Journal of Vascular Surgery - Articles in Press

Superior outcomes for rural patients after abdominal aortic aneurysm repair supports a systematic regional approach to abdominal aortic aneurysm care - Corrected Proof

Matthew W. Mell, Christie Bartels, Amy Kind, Glen Leverson, Maureen Smith — 2012-05-17

Objective: The impact of geographic isolation on abdominal aortic aneurysm (AAA) care in the United States is unknown. It has been postulated but not proven that rural patients have less access to endovascular aneurysm repair (EVAR), vascular surgeons, and high-volume treatment centers than their urban counterparts, resulting in inferior AAA care. The purpose of this study was to compare the national experience for treatment of intact AAA for patients living in rural areas or towns with those living in urban areas. Methods: Patients who underwent intact AAA repair in 2005 to 2006 were identified from a standard 5% random sample of all Medicare beneficiaries. Data on patient demographics, comorbidities, type of repair, and specialty of operating surgeon were collected. Hospitals were stratified into quintiles by yearly AAA volume. Primary outcomes included 30-day mortality and rehospitalization. Results: A total of 2616 patients had repair for intact AAA (40% open, 60% EVAR). Patients from rural and urban areas were equally likely to receive EVAR (rural 60% vs urban 61%; P = .99) and be treated by a vascular surgeon (rural 48% vs urban 50%; P = .82). Most rural patients (86%) received care in urban centers. Primary outcomes occurred in 11.6% of rural patients (1.3% 30-day mortality; 10.3% rehospitalization) vs 16.0% of urban patients (3% 30-day mortality, 13% rehospitalization; P = .04). In multivariate analyses, rural residence was independently associated with treatment at high-volume centers (odds ratio, 1.64; 95% confidence interval, 1.34-2.01; P < .0001) and decreased death or rehospitalization (odds ratio, 0.69; 95% confidence interval, 0.49-0.97; P = .03). Conclusions: Despite geographic isolation, patients in rural areas needing treatment for intact AAAs have equivalent access to EVAR and vascular surgeons, increased referral to high-volume hospitals, and improved outcomes after repair. This suggests that urban patients may be disadvantaged even with nearby access to high-quality centers. This study supports the need for criteria that define centers of excellence to extend the benefit of regionalization to all patients.

A randomized double-blind trial of upward progressive vs degressive compressive stockings in patients with moderate to severe chronic venous insufficiency - Corrected Proof

2012-05-17

Background: The present randomized double-blind multicenter study was designed to assess the efficacy of a progressive compressive stocking (new concept with maximal pressure at calf), compared to a degressive compressive stocking graded 30 mm Hg, evaluating the improvement of lower leg symptoms of chronic venous insufficiency (CVI) in ambulatory patients with moderate to severe chronic venous disease. Methods: Both gender outpatients presenting symptomatic moderate to severe CVI were eligible for a treatment by compressive stockings. Patients were randomly assigned to receive either degressive compressive stockings (30 mm Hg at ankle, 21 at upper calf) or progressive compressive stockings (10 mm Hg at ankle, 23 at upper calf). The primary outcome, evaluated after 3 months, was a composite success outcome, including improvement of pain or heavy legs without onset of either ulcer, deep or superficial vein thrombosis of the lower limbs, or pulmonary embolism. The ease of application of the compressive stockings reported by patients was one of secondary outcome. Results: Overall, 401 patients (199 in the progressive compressive stocking group and 202 in the degressive compressive stocking group) were randomized by 44 angiologists in France. Among them, 66% were classified in the C3 CEAP category. The rate of success was significantly higher in the progressive compressive stocking group compared to the degressive compressive stocking group (70.0% vs 59.6%; relative risk [RR], 1.18; 95% confidence interval [CI], 1.02-1.37; P = .03). This was mainly due to more frequent symptom improvement in the progressive compressive stocking group. The compressive stockings were considered easy to apply by 81.3% of patients in the progressive compressive stocking group vs 49.7% of patients in the degressive compressive stocking group (P < .0001). The rate of related serious adverse events was low and similar in both groups. Conclusions: This trial has demonstrated that progressive compressive stockings are more effective than usual degressive compressive stockings in the improvement of pain and lower leg symptoms in patients with CVI. Moreover, progressive compressive stockings were easier to apply, raising no safety concern at 3 months.

Lack of thrombus organization in nonshrinking aneurysms years after endovascular abdominal aortic aneurysm repair - Corrected Proof

2012-05-17

Objective: During endovascular abdominal aortic aneurysm repair (EVAR), blood is trapped in the aneurysm sac at the moment the endograft is deployed. It is generally assumed that this blood will coagulate and evolve into an organized thrombus. It is unknown whether this process always occurs, what its time span is, and how it influences aneurysm shrinkage. With magnetic resonance imaging (MRI), quantitative analysis of the aneurysm sac is possible in terms of endoleak volume as well as unorganized thrombus volume and organized thrombus volume. We investigated the presence of unorganized thrombus in nonshrinking aneurysms years after EVAR. Methods: Fourteen patients with a nonshrinking aneurysm without endoleak on computed tomography/computed tomography angiography underwent MRI with a blood pool agent (gadofosveset trisodium). Precontrast T1-, precontrast T2-, and postcontrast T1-weighted images (3 and 30 minutes after injection) were acquired and evaluated for the presence of endoleak. The aneurysm sac was segmented into endoleak, unorganized thrombus, and organized thrombus by interactively thresholding the differently weighted images. The classification was visualized in real-time as a color overlay on the MR images. The volumes of endoleak, unorganized thrombus, and organized thrombus were calculated. Results: Median time after EVAR was 2 years (range, 1-8.2 years). The average aneurysm sac volume of the patients was 167 ± 107 mL (mean ± standard deviation). Nine patients had an endoleak on the postcontrast T1-w images 30 minutes after injection. On average, the aneurysm sac contained 78 ± 61 mL unorganized thrombus, which corresponded to 51 ± 21 volume-percentage, irrespective of the presence of an endoleak on the blood pool agent enhanced MRI images (independent t-test, P = .8). Conclusions: In our study group, half of the nonshrinking aneurysm sac contents consisted of unorganized thrombus years after EVAR.

Critical analysis of renal duplex ultrasound parameters in detecting significant renal artery stenosis - Corrected Proof

2012-05-17

Background: Several published studies have reported differing results of renal duplex ultrasound (RDU) imaging in detecting significant renal artery stenosis (RAS) using different Doppler parameters. This study is the largest to date to compare RDU imaging vs angiography and assess various published Doppler criteria. Methods: RDU imaging and angiography were both done in 313 patients (606 renal arteries). RAS was classified as normal, <60%, ≥60% to 99%, and occlusion. Main outcome measurements included renal peak systolic velocity (PSV), systolic renal-to-aortic ratio (RAR), end-diastolic velocity (EDV), and kidney lengths. Results: The mean PSVs and RARs for normal, <60%, and ≥60% stenosis were 173, 236, and 324 cm/s (P < .0001), and 2.2, 2.9, and 4.5, respectively (P < .0001). The PSV cutoff value that provided the best overall accuracy for ≥60% stenosis was 285 cm/s, with a sensitivity, specificity, and overall accuracy of 67%, 90%, and 81%, respectively. The RAR cutoff value with the best overall accuracy for ≥60% stenosis was 3.7, with a sensitivity, specificity, and overall accuracy of 69%, 91%, and 82%, respectively. A PSV of ≥180 cm/s and RAR of ≥3.5 had a sensitivity, specificity, and overall accuracy of 72%, 81%, and 78% in detecting ≥60% stenosis. A PSV of ≥200 cm/s with an RAR of ≥3.5 had a sensitivity, specificity, and overall accuracy of 72%, 83%, and 78% in detecting ≥60% stenosis. A receiver operator characteristic (ROC) curve analysis showed that the PSV and RAR were better than the EDV in detecting ≥60% stenosis: PSV area under the curve (AUC) was 0.85 (95% confidence interval [CI], 0.81-0.88), EDV AUC was 0.71, and RAR AUC was 0.82 (PSV vs EDV, P < .0001; PSV vs RAR, P = .075; EDV vs RAR, P < .0001). A PSV of 285 cm/s or RAR of 3.7 alone were better than any combination of PSVs, EDVs, or RARs in detecting ≥60% stenosis. The mean kidney length was 10.4 cm in patients with ≥60% stenosis vs 11.0 cm in patients with <60% stenosis (P < .0001). Twelve percent of patients with ≥60% stenosis had a kidney length of ≤8.5 cm vs 4% in patients with <60% stenosis (P = .0003), and 5.6% (34 of 606) had accessory renal arteries on angiography, with six detected on RDU imaging. The presence of accessory renal arteries, solitary kidneys, or renal fibromuscular dysplasia had no influence on overall accuracy of using PSV values for detecting ≥60% stenosis. Conclusions: A PSV of 285 cm/s or an RAR of 3.7 alone can be used in detecting ≥60% RAS. Previously published data must be validated in individual vascular laboratories.

Discussion - Corrected Proof

2012-05-17

Dr Kimberley Hansen (Winston Salem, NC). Dr Mitchell, Dr Endean, members, and guests: Thank you for the opportunity to open this discussion, and thank you Ali for your paper well in advance and your presentation this morning. For me, the primary message from Dr AbuRahma and his group is that optimal criteria for renal duplex sonography are best obtained when each laboratory validates its results through comparative analysis. We agree wholeheartedly with this message, but the comparison may not be so easy to make as it once was. Some years ago, our first comparative analysis between renal duplex and angiography utilized cut film, not temporal digital subtraction. Digital subtraction with postprocessing—peak opacification and pixel shift functions—can affect images profoundly. With an analog-to-digital imaging system, our technologists can create just about any image you might prefer, bringing me to these questions:

Transcatheter arterial revascularization outcomes at vascular and general surgery teaching hospitals and nonteaching hospitals are comparable - Corrected Proof

2012-05-14

Background: Outcomes following transcatheter interventions at vascular and general surgery teaching hospitals (STH) are unknown. We examine whether surgery training programs influence clinically relevant outcomes after commonly performed endovascular procedures. Methods: Using an all-payer inpatient care database from 2008, we selected adults who underwent either endovascular carotid stenting, endografting of descending thoracic aortic aneurysm, endovascular abdominal aortic aneurysm repair, or peripheral arterial revascularization. Patients were stratified by procedures completed at Surgery Teaching (Participate in Accreditation Council for Graduate Medical Education [ACGME]-accredited vascular and general surgery programs), STH, or nonteaching hospitals (NTH). Hierarchical regression models assessed adverse outcomes and in-hospital mortality among groups. Results: Of the 175,698 records, 44% of the patients were treated at STH, while 56% underwent procedures at NTH. The adjusted odds ratio of any complication or mortality at STH and NTH were similar. Transfers, weekend admissions, and nonelective cases were higher at STH (P < .001, respectively). Paradoxically, STH treated fewer patients with more than three comorbidities compared with NTH (STH: 47% vs NTH: 53%; P < .001). Surgical teaching status did not lower the adjusted odds of mortality for any procedure. Moreover, the occurrence of any complication (adjusted odds ratios, 0.9; 95% confidence interval, .82-1.14; P = .69) and mortality (adjusted odds ratios, 0.9; 95% confidence interval, .74-1.22; P = .67) were equivalent between vascular and general STH. Conclusions: Following commonly performed transcatheter vascular procedures, and despite more transfers, weekend admissions, and nonelective procedures completed at STH, complications, and mortality were comparable across centers.

Comparative outcomes of primary autogenous fistulas in elderly, multiethnic Asian hemodialysis patients - Corrected Proof

2012-05-14

Background: The number of elderly (≥65 years) end-stage renal disease (ESRD) patients on hemodialysis is rapidly increasing. Vascular access outcomes remain contradictory and understudied across different elderly populations. We hypothesized age might influence primary autogenous fistula use and outcomes in a predominantly diabetic multiethnic Asian ESRD population. Methods: Demographic and clinical factors affecting fistula patency and maturation were retrospectively compared among patients with incident ESRD aged <65 and ≥65 years at a single center. Fistula patency was estimated by Kaplan-Meier curves with log-rank test comparison. Results: We analyzed 280 primary fistulas (59% radiocephalic, 33% brachiocephalic and 8% brachiobasilic) in this cohort consisting of 31.8% aged ≥65 years, 50% Chinese, 39% Malay, 42% women, and 70% diabetic. One- and 2-year primary (PP) and secondary (SP) patency in patients aged <65 vs ≥65 years were comparable: 41.3% vs 36.7% and 28.7% vs 24.4% (P = .547) and 57.7% vs 56.8% and 47.1% vs 47.2% (P = .990). On multivariate analysis, only non-Chinese, dialysis initiation with tunneled catheters, and surgical/endovascular interventions affected fistula survival hazard ratios (HR): 0.622 (95% confidence interval [CI], 0.43-1.00), 0.549 (95% CI, 0.297-0.841), and 2.503 (95% CI, 1.695-3.697), respectively. Nonmaturation and intervention rates were also similar at 56.7% vs 61.8% and 34% vs 32.2% at 3 and 6 months and 0.31 vs 0.36 per access year, respectively (P = .05). Females and tunneled catheters were the only risk factors for nonmaturation (HR, 1.568; 95% CI, 1.148-1.608, and HR, 1.623; 95% CI, 1.400-1.881, respectively). Conclusions: A primary fistula strategy in incident elderly ESRD is feasible and does not result in inferior outcomes. Age should therefore not be a determinant for primary fistula creation.

Analysis of Florida and New York state hospital discharges suggests that carotid stenting in symptomatic women is associated with significant increase in mortality and perioperative morbidity compared with carotid endarterectomy - Corrected Proof

2012-05-14

Background: Although large randomized studies have established the efficacy and safety of carotid endarterectomy (CEA) and, recently, carotid artery stenting (CAS), the under-representation of women in these trials leaves the comparison of risks to benefits of performing these procedures on women an open question. To address this issue, we reviewed the hospital outcomes and delineated patient characteristics predicting outcome in women undergoing carotid interventions using New York and Florida statewide hospital discharge databases. Methods: We analyzed in-hospital mortality, postoperative stroke, cardiac postoperative complications, and combined postoperative stoke and mortality in 20,613 CEA or CAS hospitalizations for the years 2007 to 2009. Univariate and multiple logistic regression analyses of variables were performed. Results: CEA was performed in 16,576 asymptomatic and 1744 symptomatic women and CAS in 1943 asymptomatic and 350 symptomatic women. Compared with CAS, CEA rates, in asymptomatic vs symptomatic, were significantly lower for in-hospital mortality (0.3% vs 0.8% and 0.4% vs 3.4%), stroke (1.5% vs 2.6% and 3.5% vs 9.4%), and combined stroke/mortality (1.7% vs 3.1% and 3.8% vs 10.9%). In cohorts matched by propensity scores, the same trend favoring CEA remained significant in symptomatic women. There was no difference in cardiac complication rates among asymptomatic women, but among symptomatic woman cardiac complications were more frequent after CAS (10.6% vs 6.5%; P = .0077). Among symptomatic women, the presence of renal disease, coronary artery disease, or age ≥80 years increased the risk of CAS over CEA threefold for the composite end point of stroke or death. For asymptomatic women only in those with coronary artery disease or diabetes, there was a statistical difference in the composite mortality/stroke rates favoring CEA (1.9% vs 3.3% and 1.7% vs 3.4%, respectively). After adjusting for relevant clinical and demographic risk factors and hospital annual volume, for CAS vs CEA, the risk of the composite end point of stroke or mortality was 1.7-fold higher in symptomatic and 3.4-fold higher in asymptomatic patients. Medicaid insurance, symptomatic patient, history of cancer, and presence of heart failure on admission were among other strong predictors of composite stroke/mortality outcome. Conclusions: Databases reflecting real world practice performance and management of carotid disease in women suggest that CEA compared with CAS has overall better perioperative outcomes in women. Importantly, CAS is associated with significantly higher morbidity in certain clinical settings and this should be taken into account when choosing a revascularization procedure.

Impact of endovascular options on lower extremity revascularization in young patients - Corrected Proof

2012-05-14

Objective: This study assessed outcomes of revascularization strategies in young patients with premature arterial disease. Methods: Lower extremity revascularization (LER) outcomes from 2000 to 2008 were retrospectively compared among consecutive patients with comparable indications and procedures: age <50 years (group A) at the time of revascularization, 51 to 60 years (group B), and >60 years (control group C). Patency, limb salvage, and survival by limb or patient level were assessed by Kaplan-Meier and Cox proportional hazards analyses. Results: A total of 409 limbs in 298 patients were treated: 44% for claudication and 56% for critical limb ischemia (CLI). Group A patients were more likely to be smokers and have a hypercoagulable state but less likely to have diabetes and renal failure. Treatment indications were comparable among groups, and procedures were equally distributed between open surgical and endovascular interventions. Two perioperative deaths occurred in group C (2%). Mean follow-up was 29 months, and 16% of claudicant patients in group A progressed to CLI (B, 3%; C, 2%; P < .001). Overall, 2-year primary, primary assisted, and secondary patency were significantly lower in group A (50.5%, 65.2%, 68.2%; P = .045) vs B (65.7%, 81.4%, 86.8%; P = .01) and C (57.9%, 78.9%, 83.9%; P < .001). Claudicant patients in group A had an unexpectedly low 2-year freedom from major amputation after intervention of only 90%. Results were more comparable across groups for CLI. The 2-year freedom from reintervention was similar (A, 81.0%; B, 78.9%; C, 83.5%), irrespective of the indication for intervention (P = .60). Younger patients had a significantly higher 3-year survival (A, 89.5%; B, 85.3%) compared with patients aged >60 years (C, 71.4%; P = .005). The 2-year freedom from major amputation rate was significantly lower in claudicant patients in group A vs C undergoing endovascular revascularization (P = .002), but not in patients treated with open revascularization (P = .40). Predictors of loss of primary patency included age <50 years (P = .003), endovascular revascularization (P = .005), and progression from claudication to CLI (P < .001). Age <50 years was also an independent predictor of limb loss vs age >60 years (P = .05). Conclusions: Endovascular options are commonly being used in young patients, especially those with claudication, but patency rates and outcomes remain very poor.

Suprarenal graft fixation in endovascular abdominal aortic aneurysm repair is associated with a decrease in renal function - Corrected Proof

2012-05-14

Introduction: Suprarenal endograft fixation is routinely used in the endovascular repair of abdominal aortic aneurysms (EVAR) to enhance proximal endograft attachment but can be associated with an adverse outcome in renal function. This prospective study assessed the effect of suprarenal fixation on serum creatinine concentration and estimated glomerular filtration rate (eGFR), calculated by the Modified Diet in Renal Disease equation, 12 months after elective EVAR. Methods: Patients undergoing elective EVAR were divided into suprarenal vs infrarenal fixation groups matched for age, sex, smoking, and aneurysm diameter. Serum creatinine and eGFR were measured at baseline, 6, and 12 months. Results: Included were 92 patients (2 women), with a mean age of 71 ± 7 years, with 46 in each group. No device-related complications were noted. Serum creatinine did not differ significantly between groups at 6 (P = .24) or 12 (P = .08) months but significantly increased in the suprarenal group at 12 months (1.08 ± 0.36 to 1.16 ± 0.36 mg/dL; P < .001) vs baseline. The eGFR (mL/min/1.73 m2) did not differ significantly at baseline between the suprarenal (85 ± 27) and infrarenal (80 ± 28; P = .33) groups or at 6 months (88 ± 29 vs 77 ± 24, respectively; P = .07). At 12 months, the suprarenal group had a lower eGFR (73 ± 23) than the infrarenal group (84 ± 26; P = .027). The eGFR at 12 months showed a significant decrease in the suprarenal (80 ± 28 to 73 ± 23; P < .001) but not in the infrarenal group (85 ± 27 to 84 ± 26; P = .48). The drop in eGFR differed significantly at 12 months in the infrarenal vs the suprarenal (0.82 vs −6.94; P < .001) group. No patient progressed to end-stage renal disease or disclosed a drop in eGFR > 30%. Conclusions: In contrast to previous studies, this study suggests that suprarenal endograft fixation in elective EVAR is associated with a drop in eGFR at 12 months.

A pilot study of a triple antimicrobial-bonded Dacron graft for the prevention of aortic graft infection - Corrected Proof

2012-05-14

Objective: Perioperative infection of an aortic graft is one of the most devastating complications of vascular surgery, with a mortality rate of 10% to 30%. The rate of amputation of the lower limbs is generally >25%, depending on the graft material, the location of the graft and infection, and the bacterial virulence. In vitro studies suggest that an antibiotic-impregnated graft may help prevent perioperative graft infection. In a pilot animal study, we tested a locally developed technique of bonding Dacron aortic grafts with three antimicrobial agents to evaluate the ensuing synergistic preventive effect on direct perioperative bacterial contamination. Methods: We surgically implanted a 6-mm vascular knitted Dacron graft in the infrarenal abdominal aorta of six Sinclair miniature pigs. Two pigs received unbonded, uninoculated grafts; two received unbonded, inoculated grafts; and two received inoculated grafts that were bonded with chlorhexidine, rifampin, and minocycline. Before implantation, the two bonded grafts and the two unbonded grafts were immersed for 15 minutes in a 2-mL bacterial solution containing 1 to 2 × 107 colony-forming units (CFU)/mL of Staphylococcus aureus (ATCC 29213). Two weeks after graft implantation, the pigs were euthanized, and the grafts were surgically excised for clinical, microbiologic, and histopathologic study. Results: The two bonded grafts treated with S aureus showed no bacterial growth upon explant, whereas the two unbonded grafts treated with S aureus had high bacterial counts (6.25 × 106 and 1.38 × 107 CFU/graft). The two control grafts (unbonded and untreated) showed bacterial growth (1.8 × 103 and 7.27 × 103 CFU/graft) that presumably reflected direct, accidental perioperative bacterial contamination; S cohnii ssp urealyticus and S chromogenes, but not S aureus, were isolated. The histopathologic and clinical data confirmed the microbiologic findings. Only pigs that received unbonded grafts showed histopathologic evidence of a perigraft abscess. Conclusions: Our results suggest that bonding aortic grafts with this triple antimicrobial combination is a promising method of reducing graft infection resulting from direct postoperative bacterial contamination for at least 2 weeks. Further studies are needed to explore the ability of this novel graft to combat one of the most feared complications in vascular surgery. Clinical Relevance: This study introduces a novel bonded Dacron aortic graft for the prevention of perioperative aortic graft infection. The quantitative results of our experimental studies showed that the bonding of three antimicrobial agents (rifampin, minocycline, and chlorhexidine) to aortic grafts nearly prevented aortic graft infection by synergistically prolonging antistaphylococcal activity. Use of an antibiotic-bonded prosthetic graft with antistaphylococcal activity should be considered in patients who have arterial infections caused by Staphylococcus aureus. After the preventive effect of this graft and its safety have been further assessed, its use may be recommended for the in situ replacement of infected grafts and possibly for routine primary cases, especially in immunocompromised patients, patients with hostile abdomen, and patients undergoing redo procedures.

Feasibility and validation of spinal cord vasculature imaging using high resolution ultrasound - Corrected Proof

2012-05-14

Background: A noninvasive method of visualization of the anterior spinal artery such as ultrasound that can be utilized in emergent or intraoperative settings can reduce the risk of spinal cord ischemia. Objective: We assessed the feasibility of imaging and characterizing blood flow in the anterior spinal artery using ultrasound with concurrent validation using a cadaveric model. Methods: We developed a protocol for ultrasonographic assessment of anterior spinal artery based on anatomic, morphologic, and physiologic characteristics of anterior spinal artery and determined the feasibility in 24 healthy subjects using high frequency probe (3-9 MHz) through the left lateral paramedian approach in the area between T8 and T12. We ascertained the detection rate, depth of insonation, and flow parameters, including peak systolic velocity, end diastolic velocity, and resistivity indexes for both segmental arteries and anterior spinal artery within the field of insonation. We validated the anatomical landmarks using simultaneous spinal angiography and simulated anterior spinal artery flow in a cadaveric set-up. Results: We detected flow in all segmental arteries at different levels of our field of insonation with mean depth (± standard deviation) of insonation at 3.9 ± 0.7 cm identified by characteristic high resistance flow pattern. Anterior spinal artery was detected in 15 (62.5%) subjects at mean depth (± standard deviation) of 6.4 ± 1.2 cm identified by characteristic low resistance bidirectional flow. Age, gender, and body mass index were not correlated with either the detection rate or depth of insonation for anterior spinal artery. Simultaneous spinal angiography and simulated anterior spinal artery flow in a cadaveric set-up confirmed the validity of the anatomic landmarks by demonstrating concordance with results obtained from volunteer subjects. Conclusions: The current study describes a technique for noninvasive imaging of spinal vasculature using ultrasound which may enhance our diagnostic capabilities in emergent and intraoperative settings.

Longitudinal computational fluid dynamics study of aneurysmal dilatation in a chronic DeBakey type III aortic dissection - Corrected Proof

2012-05-14

Computational fluid dynamics, which uses numeric methods and algorithms for the simulation of blood flow by solving the Navier-Stokes equations on computational meshes, is enhancing the understanding of disease progression in type III aortic dissections. To illustrate this, we examined the changes in patient-derived geometries of aortic dissections, which showed progressive false lumen aneurysmal dilatation (26% diameter increase) during follow-up. Total pressure was decreased by 29% during systole and by 34% during retrograde flow. At the site of the highest false lumen dilatation, the temporal average of total pressure decreased from 45 to 22 Pa and maximal average wall shear stress decreased from 0.9 to 0.4 Pa. These first results in the study of disease progression of type III DeBakey aortic dissection with computational fluid dynamics are encouraging.

Great saphenous vein diameter does not correlate with worsening quality of life scores in patients with great saphenous vein incompetence - Corrected Proof

Kathleen Gibson, Mark Meissner, David Wright — 2012-05-14

Objective: Previous studies have correlated increasing great saphenous vein (GSV) diameter with increasing CEAP clinical classification. Some insurance carriers are currently using specific GSV diameters to determine coverage for treatment of axial venous insufficiency. The aim of this study was to investigate the correlation of patient quality of life (QOL) measures with GSV diameters in varicose vein patients with GSV reflux. Methods: Data were collected from the records of 91 patients prospectively enrolled in two varicose vein trials. The patients had symptomatic varicose veins with saphenofemoral junction and proximal GSV reflux. Maximum GSV diameter was measured on duplex ultrasound imaging, with the patient standing, within 5 cm of the saphenofemoral junction. Chronic Venous Insufficiency Questionnaire 2 (CIVIQ-2, Servier, Neuilly-sur-Seine, France), Venous Insufficiency Epidemiological and Economic Study (VEINES) Symptom (Sym) and QOL assessments, and the Venous Clinical Severity Score (VCSS) assessment were completed before treatment of GSV insufficiency. Demographic information, patient weight, height, and body mass index were collected. Correlations between pairs of data were done using Pearson product moment and Spearman correlation coefficients. Results: The 91 study patients (19 men, 72 women) were a mean age of 45 years (range, 18-65 years). The mean GSV diameter was 6.7 mm (range, 2.2-14.1 mm). The mean VCSS score was 7.8 (range, 3-12). There was a weak correlation between increasing GSV diameter and VCSS (r = 0.23; P = .03) and no correlation between GSV diameter and the CIVIQ-2 score (r = 0.01), VEINES-QOL (r = −0.07), and VEINES-SYM (r = −0.1). Conclusions: GSV diameter is a poor surrogate marker for assessing the effect of varicose veins on a patient's QOL; thus, using GSV diameter as a sole criterion for determining medical necessity for the treatment of GSV reflux is inappropriate. Further correlations between QOL measures and duplex-derived objective findings are warranted.

Comparison of carotid endarterectomy and stenting in real world practice using a regional quality improvement registry - Corrected Proof

2012-05-14

Objective: Carotid artery stenting (CAS) vs endarterectomy (CEA) remains controversial and has been the topic of recent randomized controlled trials. The purpose of this study was to compare the practice and outcomes of CAS and CEA in a real world setting. Methods: This is a retrospective analysis of 7649 CEA and 430 CAS performed at 17 centers from 2003 to 2010 within the Vascular Study Group of New England (VSGNE). The primary outcome measures were (1) any in-hospital stroke or death and (2) any stroke, death, or myocardial infarction (MI). Patients undergoing CEA in conjunction with cardiac surgery were excluded. Multivariate logistic regression was performed to identify predictors of stroke or death in patients undergoing CAS. Results: CEA was performed in 17 centers by 111 surgeons, while CAS was performed in 6 centers by 30 surgeons and 8 interventionalists. Patient characteristics varied by procedure. Patients undergoing CAS had a higher prevalence of coronary artery disease, congestive heart failure, diabetes, and prior ipsilateral CEA. Embolic protection was used in 97% of CAS. Shunts were used in 48% and patches in 86% of CEA. The overall in-hospital stroke or death rate was higher among patients undergoing CAS (2.3% vs 1.1%; P = .03). Overall stroke, death, or MI (2.8% CAS vs 2.1% CEA; P = .32) were not different. Asymptomatic patients had similar rates of stroke or death (CAS 0.73% vs CEA 0.89%; P = .78) and stroke, death, or MI (CAS 1.1% vs CEA 1.8%; P = .40). Symptomatic patients undergoing CAS had higher rates of stroke or death (5.1% vs 1.6%; P = .001), and stroke, death, or MI (5.8% vs 2.7%; P = .02). By multivariate analysis, major stroke (odds ratio, 4.5; 95% confidence interval [CI], 1.9-10.8), minor stroke (2.7; CI, 1.5-4.8), prior ipsilateral CEA (3.2, CI, 1.7-6.1), age >80 (2.1; CI, 1.3-3.4), hypertension (2.6; CI, 1.0-6.3), and a history of chronic obstructive pulmonary disease (1.6; CI, 1.0-2.4) were predictors of stroke or death in patients undergoing carotid revascularization. Conclusions: In our regional vascular surgical practices, the overall outcomes of CAS and CEA are similar for asymptomatic patients. However, symptomatic patients treated with CAS are at a higher risk for stroke or death.

Use, misuse, and underuse of work relative value units in a vascular surgery practice - Corrected Proof

Bhagwan Satiani — 2012-05-14

Health care reform is forcing “alignment” between hospitals and physicians. The acceleration of employment of physicians by hospitals is bringing into focus contractual terms where compensation is tied to clinical productivity. Physician productivity is being almost entirely defined by work relative value units (WRVUs). However, vascular surgeons may bring value to a health system in ways that are unique and separate from clinical revenue as measured by WRVUs. Incentives for physicians should also be tied to behaviors that are desired, such as quality of care, efficiency, patient outcomes, patient satisfaction scores, teaching, and research, depending on the specific environment. Vascular surgeons must be aware of proper use and misuse of WRVUs and have access to the most appropriate benchmarks in negotiations for employment. With increasing employment of physicians by hospitals and focus on “alignment,” a more comprehensive measure of physician productivity is necessary.

Intermittent claudication caused by a giant atypical lipoma of the thigh - Corrected Proof

2012-05-14

The main cause of intermittent claudication in lower limbs is peripheral vascular disease. Less commonly, the etiology can be extrinsic to vascular structures, as in the cases of tumors that, due to their rapid growth, can reduce the blood supply and produce intermittent claudication during gait. We report the case of a 49-year-old patient with intermittent claudication in the left lower limb, reporting the presence of a tumor in the inner side of the left thigh with rapid growth. Doppler and angiography magnetic resonance imaging examinations demonstrated the presence of an adipose tumor that was producing deep and superficial extrinsic compression of the femoral arteries.

Long-term result of endovascular treatment for patients with nutcracker syndrome - Corrected Proof

Xiaobai Wang, Yan Zhang, Chengzhi Li, Hong Zhang — 2012-05-10

Objective: To retrospectively assess the therapeutic value of endovascular stenting for treatment of the nutcracker syndrome (NCS) in long-term follow-up and to explore the selection of the size of stents in Chinese patients with NCS. Methods: From January 2004 to August 2010, 30 patients (two women and 28 men) between 13 and 32 years old (mean, 18.2) who were diagnosed with NCS were admitted for endovascular treatment. Each patient received one self-expanding metallic stent (14-mm diameter, 60 mm long) in the compressed portion of the left renal vein during the operation, and three patients with severe left-sided varicoceles received left gonadal vein embolization. The postoperative follow-up was 12 to 80 months (median, 36.0 months). Results: The diameters at the ostium of left renal vein measured by the ultrasonic examination before treatment were 11.8 ± 1.8 mm. Technical success of operation was achieved in all patients. No perioperative complications occurred. Two cases of stent migration were found at 12 months: both stents prolapsed into the inferior vena cava, with uneventful follow-up (49 and 56 months, respectively). At 1-month follow-up, patients improved, including two patients who had persistent but less microscopic hematuria than before treatment. The clinical symptoms related to NCS almost disappeared at 3 months after the treatment. All stents were patent at the duplex scan examination, without restenosis, and no secondary recurrence of the symptoms occurred at the end of the follow-up. Conclusions: Endovascular treatment is a safe, effective, and very minimally invasive technique that provides good long-term patency rates for patients with NCS, and under the premise morphologic measurements, 14-mm-diameter, 60-mm-long self-expanding stents should be first considered for Chinese patients with NCS.

The impact of gender on outcome after infrainguinal arterial reconstructions for peripheral occlusive disease - Corrected Proof

2012-05-10

Objective: The role of gender on the outcome of infrainguinal arterial revascularization (IAR) for peripheral arterial occlusive disease remains uncertain. This study analyzed the outcome of IARs performed over 15 years, stratifying the results by sex. Methods: Details of consecutive patients undergoing primary IAR for peripheral arterial occlusive disease from 1995 to 2009 at our institution were prospectively stored in a vascular registry. Demographics, risk factors, indications for surgery, inflow sources, outflow target vessels, types of conduit, and adverse outcomes were analyzed. Postoperative surveillance included clinical examination supplemented with duplex scans and ankle-brachial index measurements in all patients at discharge, 30 days, 6 months, and every 6 months thereafter. End points of the study, ie, patency, limb salvage, and survival rates, were assessed using Kaplan-Meier life-table analysis. The χ2 or Fisher exact, Student t, and log-rank tests were used to establish statistical significance. Results: Our sample consisted of 1459 IARs performed in 1333 patients, comprising 496 women (37.2%; 531 IARs), who were a mean 3 years older than the men (74 vs 71 years; P < .001) and had a higher incidence of diabetes mellitus (52% vs 46%; P = .03) and surgery for limb salvage (91% vs 87%; P = .02). An autogenous vein conduit (great or small saphenous, or both, spliced, arm, or composite veins) was used in 87% of the IARs. No deaths occurred perioperatively (30 days). The major and minor complication rates were comparable between men and women. At 10 years, the primary patency rate was 47% in women vs 49% in men (P = .67), the assisted primary patency rate was, respectively, 53% vs 50% (P = .69), the secondary patency rate was 61% vs 61% (P = .66), limb salvage rate was 93% vs 91% (P = .54), and survival rate was 43% vs 49% (P = .65). Stratifying by type of conduit revealed no differences in patency or limb salvage rates. Conclusions: Despite an older age and more advanced stages of disease on presentation in women, IAR performed in women can achieve patency and limb salvage rates statistically no different from those recorded in their male counterparts, supporting the conviction that sex per se does not influence the outcome of lower extremity revascularization.

Midterm outcomes of endovascular aneurysm repair with selective internal iliac artery coverage without coil embolization - Corrected Proof

2012-05-10

Objective: Endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms (AAAs) that also involve the common iliac artery (CIA) typically is accomplished by endograft limb extension into the external iliac artery (EIA). In order to prevent endoleak, the internal iliac artery (IIA) is usually embolized, or alternatively a branched limb is deployed. However, IIA embolization is associated with longer operative time and increased use of contrast and radiation. It has been our practice not to routinely coil embolize the IIA. The purpose of this study was to present the midterm outcomes of this approach. Methods: Between April 1997 and June 2010, 137 patients (130 men; mean age, 70.9 years; range, 45-92 years) underwent EVAR of their AAA and had IIA coverage without coil embolization in 112 patients (no embolization [NE] group) and after coil embolization in 25 patients (coil embolization [CE] group). Anatomic indications for coverage of the IIA without coil embolization included presence of adequate sealing in the distal 5 mm of the CIA, or sealing ring at the origin of the CIA, or IIA diameter <5 mm. Preoperative mean AAA size was 60 ± 14 mm, and mean CIA diameter was 38 ± 13 mm. Postoperative computed tomography (CT) scanning was performed at 1, 6, and 12 months, and yearly thereafter. Results: Thirty-day mortality was 0.7% (1 of 137 patients). A patient presented with gluteal skin necrosis (0.7%). The incidence of postoperative buttock claudication was not different between the two groups (NE: 15 of 112 patients; CE: 3 of 25 patients; P = .852). Procedure and fluoroscopy time, contrast use, and hospital stay were significantly reduced in the NE group. Patients were followed up for 33 ± 30 months. During follow-up, 44 patients died (32.1%) and in 3 of them (2.2%), death was AAA-related. There was no difference in cumulative survival between the two groups at 1, 2, 3, and 4 years, respectively. Secondary interventions were performed in 20 of 137 patients (14.5%), including three conversions for proximal endoleak. There was no difference between the two groups in the incidence of secondary interventions (NE: 18 of 112 patients; CE: two of 25 patients; P = .301) and freedom from reintervention at 1, 2, 3, and 4 years, respectively. Ten patients (8.9%) from the NE group presented a type II endoleak during follow-up. Seven of them were associated with the covered IIA; none required reintervention. Conclusions: Stent graft coverage of the IIA without coil embolization is a safe, simple, and effective maneuver for the treatment of aortoiliac aneurysms, with a low incidence of postoperative complications and reinterventions and acceptable immediate and midterm results.

Long-term results of femoral vein transposition for autogenous arteriovenous hemodialysis access - Corrected Proof

Pierre Bourquelot, Marek Rawa, Olivier Van Laere, Gilbert Franco — 2012-05-10

Introduction: When all access options in the upper limbs have been exhausted, an autogenous access in lower limb is a valuable alternative to arteriovenous grafts. We report our experience of transposition of the femoral vein (tFV). Methods: From June 1984 to June 2011, 70 patients underwent 72 tFV in two centers (Paris and Meknès) with the same technique. All patients had exhausted upper arm veins or had central vein obstructions. Patients were followed by serial duplex scanning. All complications were recorded and statistical analysis of patency was performed according to intention to treat using the life-table method. Results: The mean interval between initiation of dialysis and creation of the tFV was 10 years. The sex ratio was even (one female/one male). Mean age was 48 years (range, 1-84 years), and there were no postoperative infections. Duplex measurements in 33 patients indicated high-flow: mean = 1529 ± 429 mL/min; range, 700-3000 mL/min. Two immediate failures were observed and four patients were lost to follow-up soon after the access creation. Ten patients (14%) experienced minor complications (hematoma, five; lymphocele, one; delayed wound healing, two; distal edema, two) and 30 patients (42%) experienced mild complications (femoral vein and outflow stenosis, 16; treated by percutaneous transluminal angioplasty, 13; or polytetrafluoroethylene patch, three; puncture site complications, three [ischemia, two; infection, one]; reversible thrombosis, three [two surgical and one percutaneous thrombectomy]; abandoned thrombosis, eight [11%] after a mean patency of 8.1 years). Thirteen patients (18%) experienced major complications necessitating fistula ligation (ischemic complications in five diabetic patients with peripheral arterial occlusive disease [one major amputation included], lower leg compartment syndrome, one; acute venous hypertension, two; secondary major edema, two; high-output cardiac failure, one; bleeding, two). All the patent accesses (59/72) were utilized for dialysis after a mean interval of 2 ± 1 months (range, 1-7 months) resulting in an 82% success rate. According to life-table analysis, the primary patency rates at 1 and 9 years were 91% ± 4% and 45% ± 11%, respectively. The secondary patency rates at 1 and 9 years were 84% ± 5% and 56% ± 9%, respectively. Conclusions: Femoral vein transposition in the lower limb is a valuable alternative to arteriovenous grafts in terms of infection and long-term patency. Secondary venous percutaneous angioplasties may be necessary. High flow rates are frequently observed and patient selection is essential to avoid ischemic complications.

Endovascular repair of ruptured abdominal aortic aneurysm does not confer survival benefits over open repair - Corrected Proof

2012-05-10

Objective: Endovascular repair of ruptured abdominal aortic aneurysm (rAAA) is being increasingly performed despite lack of good-evidence for its superiority. Other reported studies suffer from patient selection and publication bias with limited follow-up. This study is a single center propensity score comparing early and midterm outcomes between open surgical repair (OSR) and endovascular repair of rAAA (REVAR). Methods: A retrospective review from January 2001 to November 2010 identified 312 patients who underwent rAAA repairs. Thirty-one patients with antecedent AAA repair and three with incomplete records were excluded, leaving 37 REVARs and 241 OSRs. Propensity score-based matching for sex, age, preoperative hemodynamic status, surgeon's annual AAA volume, and preoperative cardiopulmonary resuscitation was performed in a 1:3 ratio to compare outcomes. Thirty-seven REVARs were matched with 111 OSRs. Late survival was estimated by Kaplan-Meier methods. Results: Operative time and blood replacement were higher with OSR. Overall complication rates were similar (54% REVAR vs 66% OSR; P = .23), except for higher incidences of tracheostomies (21% vs 3%; P = .015), myocardial infarction (38% vs 18%; P = .036), and acute tubular necrosis (47% vs 21%; P = .009) with OSR. Operative mortality rates were similar (22% REVAR vs 32% OSR), with an odds ratio of 0.63 for REVAR (95% CI = [0.24, 1.48]; P = .40). No differences in the incidences for secondary interventions for aneurysm- or graft-related complications were noted (22% REVAR vs 22% OSR; P = .99). Kaplan-Meier estimates of 1-, 2-, and 3-year survival rates were also similar (50%, 50%, 42% REVAR vs 54%, 52%, 47% OSR; P = .66). Conclusions: REVAR for rAAA does not seem to conclusively confer either acute or late survival advantages. Routine use of REVAR should be deferred until prospective, randomized trial data become available.

Staged total abdominal debranching and thoracic endovascular aortic repair for thoracoabdominal aneurysm - Corrected Proof

2012-05-10

Objective: Thoracoabdominal aortic aneurysms (TAAAs) occur most commonly in elderly individuals, who are often suboptimal candidates for open repair because of significant comorbidities. The availability of a hybrid option, including open visceral debranching with endovascular aneurysm exclusion, may have advantages in these patients who are at high-risk for conventional repair. This report details the evolution of our technique and results with complete visceral debranching and endovascular aneurysm exclusion for TAAA repair in high-risk patients. Methods: Between March 2005 and June 2011, 47 patients (51% women) underwent extra-anatomic debranching of all visceral vessels, followed by aneurysm exclusion by endovascular means at a single institution. A median of four visceral vessels were bypassed. The debranching procedure was initially performed through a partial right medial visceral rotation approach, leaving the left kidney posterior in the first 22 patients, and in the last 25 by a direct anterior approach to the visceral vessels. The debranching and endovascular portions of the procedure were performed in a single operation in the initial 33 patients and as a staged procedure during a single hospital stay in the most recent 14. Results: Median patient age was 71.0 ± 9.8 years. All had significant comorbidity and were considered suboptimal candidates for conventional repair: 55% had undergone previous aortic surgery, 40% were American Society of Anesthesiologists (ASA) class 4, and baseline serum creatinine was 1.5 ± 1.3 mg/dL. The 30-day/in-hospital rates of death, stroke, and permanent paraparesis/plegia were 8.5%, 0%, and 4.3%, respectively, but 0% in the most recent 14 patients undergoing staged repair. These patients had significantly shorter combined operative times (314 vs 373 minutes), decreased intraoperative red blood cell transfusions (350 vs 1400 mL), and were more likely to be extubated in the operating room (50% vs 12%) compared with patients undergoing simultaneous repair. Over a median follow-up of 19.3 ± 18.5 months, visceral graft patency was 97%; all occluded limbs were to renal vessels and clinically silent. There have been no type I or III endoleaks or reinterventions. Kaplan-Meier overall survival is 70.7% at 2 years and 57.9% at 5 years. Conclusions: Hybrid TAAA repair through complete visceral debranching and endovascular aneurysm exclusion is a good option for elderly high-risk patients less suited to conventional repair in centers with the requisite surgical expertise with visceral revascularization. A staged approach to debranching and endovascular aneurysm exclusion during a single hospitalization appears to yield optimal results.

Improved long-term results using Onyx glue for the treatment of persistent type 2 endoleak after endovascular aneurysm repair - Corrected Proof

2012-05-10

Objective: Persistent type 2 (PT2) endoleaks (present ≥6 months) after endovascular aneurysm repair (EVAR) are associated with adverse outcomes, and selective secondary intervention is indicated in those patients with an expanding aneurysm sac. This study evaluated the outcomes of secondary intervention for PT2. Methods: From 1999 to 2007, 136 patients who underwent EVAR developed PT2 and comprised the study cohort. Primary end points included PT2 resolution (secondary interventional success) and survival, and were evaluated using multiple logistic regression and Kaplan-Meier analyses, respectively. Results: Fifty-one patients underwent a total of 68 secondary interventions for PT2 with expanding aneurysm sacs with a median postsecondary interventional follow-up of 13.7 months. Secondary interventions included 20 inferior mesenteric artery (IMA) coil embolizations, 17 Onyx glue embolizations, 11 aneurysm sac coil embolizations, 10 non-Onyx glue embolizations, 7 lumbar artery coil embolizations, 2 open lumbar ligations, and 1 graft explant. The overall secondary interventional success rate was 43% (29 of 68). Onyx glue embolization was associated with a greater success rate when used as the initial secondary intervention (odds ratio [OR], 59.61; 95% confidence interval [CI], 4.78-742.73; P < .001). There was no difference in success between the different techniques when multiple secondary interventions were required. Five-year survival was 72% ± 0.08% and was unrelated to any of the secondary interventional techniques. Conclusions: Secondary intervention for PT2 is associated with success in less than half of all cases. Onyx glue embolization was associated with greater long-term success when used as the initial secondary intervention.

Successful thrombolysis, angioplasty, and stenting of delayed thrombosis in the vena cava following percutaneous vertebroplasty with polymethylmethacrylate cement - Corrected Proof

Suh Min Kim, Seung-Kee Min, Hwan Jun Jae, Sang-Il Min, Jongwon Ha, Sang Joon Kim — 2012-05-10

Percutaneous vertebroplasty is a widely used treatment for vertebral compression fracture. It is relatively safe, but it can be complicated by pulmonary or cerebral embolism caused by the cement injected during the procedure. Here, we present a case of a 69-year-old male with extensive deep vein thrombosis from the inferior vena cava to the right iliac and left femoral veins, which occurred 10 months after vertebroplasty. He was treated successfully by catheter-directed thrombolysis, angioplasty, and stenting. To the best of our knowledge, this is the first report of the successful treatment of delayed thrombosis caused by migrated cement inside the inferior vena cava.

Multiple congenital ectatic and fusiform arterial aneurysms associated with lower limb hypoplasia - Corrected Proof

2012-05-10

Aneurysmal disease is uncommon in children, and its presence often leads to suspicion of genetic disorders (Loeys-Dietz syndrome, Marfan syndrome, Ehlers-Danlos syndrome, tuberous sclerosis), trauma, and infection. We describe the case of a newborn boy with generalized left lower limb hypoplasia associated with diffuse areas of arteriectasis combined with areas of stenosis and fusiform aneurysms of the iliac, femoral, and popliteal arteries. No additional vascular territories were affected. The patient was asymptomatic, and no therapeutic intervention has been considered. Numerous complementary imaging and laboratory examinations failed to establish a definitive diagnosis. This collection of findings has not been previously reported.

Efficacy and durability of endovascular thoracoabdominal aortic aneurysm repair using the caudally directed cuff technique - Corrected Proof

2012-05-07

Purpose: This study determined early and intermediate results of multibranched endovascular thoracoabdominal (TAAA) and pararenal aortic aneurysm (PRAA) repair using a uniform operative technique. Methods: Eighty-one patients (mean age, 73 ± 8 years, 19 [23.5%] women) underwent endovascular TAAA repair in a prospective trial using self-expanding covered stents connecting axially oriented, caudally directed cuffs to target aortic branches. Mean aneurysm diameter was 67 ± 10 mm. Thirty-nine TAAA (48.1%) were Crawford type II, III, or V; 42 (51.9%) were type IV or pararenal. Thirty-three procedures (40.7%) were staged. The insertion approach was femoral for aortic components and brachial for branch components. Follow-up assessments were performed at 1, 6, and 12 months, and yearly thereafter. Results: All devices (n = 81) and branches (n = 306) were successfully inserted and deployed, with no conversions to open repair. Overall mortality was 6.2% (n = 5), including three perioperative (3.7%) and two late treatment-related deaths (2.5%). Permanent paraplegia occurred in three patients (3.7%), and transient paraplegia/paraparesis occurred in 16 (19.8%). Four patients (4.9%) required dialysis postoperatively, three permanently and one transiently. Women accounted for 67% of the paraplegia, 75% of the perioperative dialysis, and 60% of the perioperative or treatment-related deaths. During a mean follow-up of 21.2 months, no aneurysms ruptured, but four (4.9%) enlarged: two were successfully treated, one was unsuccessfully treated, and one was not treated. No late onset spinal cord ischemia symptoms developed. Of the five patients starting dialysis during follow-up, two resulted from renal branch occlusion. Sixteen branches occluded (nine renal, two celiac) or developed stenoses (four renal, one superior mesenteric artery), requiring stenting. Primary patency was 94.8%, and primary-assisted patency was 95.1%. Thirty-two patients (39.5%) underwent 42 reinterventions. Of 25 early reinterventions (≤45 days), 10 were to treat access or insertion complications, and 5 were for endoleak. Of 17 late reinterventions, eight were for endoleak and five were for branch stenosis/occlusion. New endoleaks developed in two patients during follow-up. Overall, 73 of 81 patients (90.1%) were treated without procedure-related death, dialysis, paralysis, aneurysm rupture, or conversion to open repair. Conclusions: Total endovascular TAAA/PRAA repair using caudally directed cuffs is safe, effective, and durable in the intermediate term. The most common form of late failure, renal artery occlusion, rarely had a clinically significant consequence (dialysis). The trend toward worse outcome in women needs further study.

Endovascular treatment of thoracoabdominal aortic aneurysms - Corrected Proof

2012-05-07

Background: Development in endograft design has extended endovascular treatment to include thoracoabdominal aortic aneurysms (TAAA). We report our experience using fenestrated and branched endografts in the management of TAAA. Methods: We analyzed a cohort of consecutive patients treated electively for TAAA using endovascular techniques between 2006 and 2011. All data were collected prospectively. The relationships between preoperative risk factors and clinical outcome were examined using univariate and multivariate statistical techniques. We also compared the outcomes between 33 previously published early cases (EC) with the last 56 later cases (LC). Results: Eighty-nine patients (83 men) were treated. Median age was 69 years. All patients were deemed unfit for open surgery. The 30-day and in-hospital mortality rates were 8.9% and 10%, respectively. Multivariate analysis showed in-hospital mortality was associated with preoperative chronic renal failure and advanced age. Higher postoperative mean arterial blood pressure was a protective factor. Technical success rate was 96.6% (94% and 98% in the EC and LC groups, respectively; P = .14). The spinal cord ischemia (SCI) rate was 7.8% (15% and 3% in the EC and LC groups, respectively; P = .063) and was associated with chronic obstructive pulmonary disease and procedure duration. Six patients (6.7%) required temporary filtration, but none required permanent renal support (associated with left ventricular ejection fraction <40% and procedure duration). Median procedure duration decreased from 232 to 203 minutes (P = .01) in the EC and LC groups, respectively. Actuarial survival was 86.8% ± 3.7% at 1 year and 74.7% ± 6% at 2 years. Conclusions: Although we have treated a cohort at high operative risk, our midterm results compare favorably with the published series of conventional surgery. Accurate hemodynamic control represented by high-normal perioperative blood pressure seems to protect against severe postoperative complications.

Use of a postoperative insulin protocol decreases wound infection in diabetics undergoing lower extremity bypass - Corrected Proof

2012-05-07

Objective: Strict glucose control in patients undergoing coronary bypass grafting has been shown to decrease infectious complications, arrhythmias, and mortality. Our objective was to determine if strict glucose control reduced morbidity after lower extremity bypass (LEB). Methods: A prospective pilot study at a single institution within the Vascular Study Group of New England was conducted from January 2009 to December 2010. Patients with diabetes and without undergoing LEB were placed on an intravenous (IV) insulin infusion for 3 days after surgery with titration of blood glucose from 80 to 150 mg/dL. The IV insulin study group (n = 104) was compared to a historic control group (n = 189) that received standard insulin treatment from the preceding 3 years. The Fisher exact test, t-tests, Wilcoxon rank-sum tests, χ2, and logistic regression analyses were used to compare in-hospital morbidity. Stratified analyses were conducted to determine if findings differed based on the presence or absence of diabetes. Results: There was no difference in postoperative complications between the two groups with regard to graft infection, myocardial infarction, dysrhythmia, primary patency at discharge, or mortality. Patients in the IV insulin group had significantly fewer in-hospital wound infections (4% vs 11%; odds ratio [OR], 0.32; 95% confidence interval [CI], 0.11-0.96; P = .047). This association strengthened after adjusting for potentially confounding baseline differences in gender, body mass index, and smoking status (adjusted OR, 0.22; 95% CI, 0.05-0.84; P = .03). When stratified by presence of diabetes, wound infections were decreased in the IV insulin group (0/44 [0%] vs 9/90 [10%]; P = .03.). In patients without diabetes treated with IV insulin, there was no significant difference in wound infections (7% vs 12%; P = .42). Conclusions: Strict glucose control with a postoperative insulin infusion protocol significantly decreased the incidence of postoperative in-hospital wound infection in the diabetic population. These previously unreported findings from this single-institution prospective study warrant further investigation.

Clopidogrel use before renal artery angioplasty with/without stent placement resulted in tertiary procedure risk reduction - Corrected Proof

2012-05-07

Objective: Contrary to coronary artery literature, the effect of preprocedural clopidogrel on renal artery restenosis (RAR) has not been characterized. This study was designed to evaluate the effect of preprocedural clopidogrel on target vessel revascularization (TVR), reintervention, and restenosis for patients who underwent recurrent renal artery angioplasty. Methods: A retrospective analysis of patients treated for RAR in single tertiary center from January 1999 to December 2009 was conducted. Patients were divided into preadmission use of: (1) clopidogrel or (2) aspirin only (acetylsalicylic acid [ASA]) for the initial procedure. TVR was defined as occurrence of a tertiary procedure for symptomatic RAR. Rate of freedom from event (ie, tertiary restenosis and TVR) was analyzed using Kaplan-Meier method. Results: Eighty-eight interventions were performed on 77 patients with RAR, 66% were females with average (mean ± SEM) age and body mass index of 68.8 ± 1.1 and 28.6 ± 0.8, respectively. Comorbidities included 96% chronic hypertension, 33% diabetes, 76% hyperlipidemia, 20% renal insufficiency, 39% tobacco use, 58% coronary artery disease, and 51% peripheral vascular disease. Clopidogrel use increased significantly during the index procedure from admission 35.2% to discharge 97.7% (P < .001, McNemar test). There was a trend toward risk reduction of a tertiary intervention (23%) for patients admitted on clopidogrel compared with ASA (P = .052). Likewise, there was a trend (P = .051) toward increased freedom from a tertiary intervention, with cumulative freedom at 8 years 93.5% for clopidogrel vs 61% for ASA. No differences were found for restenosis. Conclusions: The use of preprocedural clopidogrel was associated with a possible risk reduction of TVR reintervention, but this finding needs to be validated in randomized clinical trial.

A comparison of outcomes associated with carotid artery stent placement performed within and outside clinical trials in the United States - Corrected Proof

2012-05-07

Background: A discrepancy between characteristics of patients treated with carotid angioplasty and stent placement (CAS) within and outside clinical trials, particularly characteristics with direct impact on clinical outcome, may limit generalization of clinical trial results. The objective of this study was to identify differences in demographic and clinical characteristics and outcomes related to CAS in patients treated within clinical trials and those treated outside clinical trials in a large national cohort. Methods: We determined the frequency of CAS performed within and outside clinical trials and associated in-hospital outcomes using data from the Nationwide Inpatient Survey data files from 2005 to 2009. All the in-hospital outcomes were analyzed after adjusting for potential confounders using multivariate analysis. Results: Of the 81,638 patients who underwent CAS, 16,078 (19.6%) underwent the procedure as part of a clinical trial. The mean age of the patients was significantly lower in patients treated with CAS as part of a clinical trial than those treated with CAS outside a clinical trial. The proportion of women and nonwhites was lower among patients treated with CAS as part of a clinical trial. The in-hospital mortality was two-fold higher among patients treated with CAS outside clinical trials (1.12% vs 0.53%; P = .0005). The rate of composite endpoint of stroke, cardiac events, and death was significantly higher among patients treated with CAS outside clinical trials (P = .02). After adjusting for age, gender, presence of renal failure, and hospital bed size, CAS performed as part of a clinical trial was associated with lower rates of in-hospital mortality (odds ratio, 0.467; 95% confidence interval, 0.290-0.751; P = .0017) and composite endpoint of stroke, cardiac events, and death (odds ratio, 0.752; 95% confidence interval, 0.594-0.952; P = .0180). Conclusions: Our results suggest that CAS procedures performed as part of clinical trials was associated with lower rates of in-hospital mortality and composite endpoint of stroke, cardiac events, and death in United States. These findings highlight the need for strategies that ensure appropriate adoption of CAS to ensure that the benefits observed in clinical trials can be replicated in general practice.

Accelerated aneurysmal dilation associated with apoptosis and inflammation in a newly developed calcium phosphate rodent abdominal aortic aneurysm model - Corrected Proof

2012-05-07

Objective: The calcium chloride (CaCl2) model is a widely accepted rodent model for abdominal aortic aneurysms (AAAs). Calcium deposition, mainly consisting of calcium phosphate (CaPO4) crystals, has been reported to exist in human and experimental aneurysms. CaPO4 crystals have been used for in vitro DNA transfection by mixing CaCl2 and phosphate-buffered saline (PBS). Here, we describe accelerated aneurysm formation resulting from a modification of the CaCl2 model. Methods: A modified CaCl2 model, the CaPO4 model, was created by applying PBS onto the mouse infrarenal aorta after CaCl2 treatment. Morphologic, histologic, and immunohistochemical analyses were performed on arteries treated with the CaPO4 model and the conventional CaCl2 model as the control. In vitro methods were performed using a mixture of CaCl2 and PBS to create CaPO4 crystals. CaPO4- induced apoptosis of primary cultured mouse vascular smooth muscle cells (VSMCs) was measured by DNA fragmentation enzyme-linked immunosorbent assay. Results: The CaPO4 model produces AAA, defined as an increase of ≥50% in the diameter of the aorta, faster than in the CaCl2 model. The CaPO4 model showed significantly larger aneurysmal dilation at 7, 28, and 42 days, as reflected by a maximum diameter (measured in mm) fold-change of 1.69 ± 0.07, 1.99 ± 0.14, and 2.13 ± 0.09 vs 1.22 ± 0.04, 1.48 ± 0.07, and 1.68 ± 0.06 in a CaCl2 model, respectively (n = 6; P < .05). A semiquantitative grading analysis of elastin fiber integrity at 7 days revealed a significant increase in elastin degradation in the CaPO4 model compared with the CaCl2 model (2.7 ± 0.2 vs 1.5 ± 0.2; n = 6, P < .05). A significantly higher level of apoptosis occurred in the CaPO4 model (apoptosis index at 1, 2, and 3 days postsurgery: 0.26 ± 0.14, 0.37 ± 0.14, and 0.33 ± 0.08 vs 0.012 ± 0.10, 0.15 ± 0.02, and 0.12 ± 0.05 in the conventional CaCl2 model; n = 3; P < .05). An enhancement of macrophage infiltration and calcification was also observed at 3 and 7 days in the CaPO4 model. CaPO4 induced approximately 3.7 times more apoptosis in VSMCs than a mixture of CaCl2 (n = 4; P < .0001) in vitro. Conclusions: The CaPO4 model accelerates aneurysm formation with the enhancement of apoptosis, macrophage infiltration, and calcium deposition. This modified model, with its rapid and robust dilation, can be used as a new model for AAAs. Clinical Relevance: Animal models of abdominal aortic aneurysms (AAAs) have been used in a range of experiments to explore various aspects of pathogenesis and potential methods of treatment. The conventional calcium chloride (CaCl2) model has been widely accepted as an experimental animal model with many pathologic similarities with human AAAs. This conventional model typically shows aneurysmal dilation at 4 to 6 weeks after injury. We have created a mouse experimental AAA model with rapid and robust aneurysmal dilation through the modification of the conventional CaCl2 model that uses calcium phosphate. This modified model, with its rapid and robust dilation, can be used as a new model for AAAs.

Long-term limb salvage and survival after endovascular and open revascularization for critical limb ischemia after adoption of endovascular-first approach by vascular surgeons - Corrected Proof

Hasan H. Dosluoglu, Purandath Lall, Linda M. Harris, Maciej L. Dryjski — 2012-05-07

Objective: The adoption of endovascular interventions has been reported to lower amputation rates, but patients who undergo endovascular and open revascularization are not directly comparable. We have adopted an endovascular-first approach but individualize the revascularization technique according to patient characteristics. This study compared characteristics of patients who had endovascular and open procedures and assessed the long-term outcomes. Methods: From December 2002 to September 2010, 433 patients underwent infrainguinal revascularization for critical limb ischemia (CLI; Rutherford IV-VI) of 514 limbs (endovascular: 295 patients, 363 limbs; open: 138 patients, 151 limbs). Patency rates, limb salvage (LS), and survival, as also their predictors, were calculated using Kaplan-Meier and multivariate analysis. Results: The endovascular group was older, with more diabetes, renal insufficiency, and tissue loss. More reconstructions were multilevel (72% vs 39%; P < .001) and the most distal level of intervention was infrapopliteal in the open group (64% vs 49%; P = .001). The 30-day mortality was 2.8% in the endovascular and 6.0% in the open group (P = .079). Mean follow-up was 28.4 ±23.1 months (0-100). In the endovascular vs open groups, 7% needed open, and 24% needed inflow/runoff endovascular reinterventions with or without thrombolysis vs 6% and 17%. In the endovascular vs open group, 5-year LS was 78% ± 3% vs 78% ± 4% (P = .992), amputation-free survival was 30% ± 3% vs 39% ± 5% (P = .227), and survival was 36% ± 4% vs 46% ± 5% (P = .146). Five-year primary patency (PP), assisted-primary patency (APP), and secondary patency (SP) rates were 50 ± 5%, 70 ± 5% and 73 ± 6% in endovascular, and 48 ± 6%, 59 ± 6% and 64 ± 6% in the open group, respectively (P = .800 for PP, 0.037 for APP, 0.022 for SP). Multivariate analysis identified poor functional capacity (hazard ratio, 3.5 [95% confidence interval, 1.9-6.5]; P < .001), dialysis dependence (2.2 [1.3-3.8]; P = .003), gangrene (2.2 [1.4-3.4]; P < .001), need for infrapopliteal intervention (2.0 [1.2-3.1]; P = .004), and diabetes (1.8 [1.1-3.1]; P = .031) as predictors of limb loss. Poor functional capacity (3.3 [2.4-4.6]; P < .001), coronary artery disease (1.5 [1.1-2.1]; P = .006), and gangrene (1.4 [1.1-1.9]; P = .007) predicted poorer survival. Statin use predicted improved survival (0.6 [0.5-0.8]; P = .001). Need for infrapopliteal interventions predicted poorer PP (0.6 [0.5-0.9-2.2]; P = .007), whereas use of autologous vein predicted better PP (1.8 [1.1-2.9]; P = .017). Conclusions: Patients who undergo endovascular revascularization for CLI are medically higher-risk patients. Those who have bypass have more complex disease and are more likely to require multilevel reconstruction and infrapopliteal intervention. Individualizing revascularization results in optimization of early and late outcomes with acceptable LS, although survival remains low in those with poor health status.

Endovascular management of carotid artery stenosis secondary to sclerosing mediastinitis - Corrected Proof

Christopher J. Smolock, Shanda Blackmon, Zsolt Garami, Heitham T. Hassoun — 2012-05-07

Sclerosing mediastinitis is a rare, progressive condition characterized by extensive fibrotic reaction. We report the first known case of symptomatic, extrinsic compression of the carotid artery by fibrotic extension of sclerosing mediastinitis. A 54-year-old woman began experiencing neurologic symptoms from extension of a known mediastinal mass resulting in 70% to 79% stenosis of the right internal carotid artery. The stenosis was treated with endovascular stenting. Completion angiogram revealed a good result with <10% residual stenosis. At 18-month follow-up, the patient was symptom free without evidence of re-stenosis. Endovascular therapy provides a novel and durable solution in the midterm to this very rare problem.

Incidence and predisposing factors of cold intolerance after arterial repair in upper extremity injuries - Corrected Proof

2012-05-07

Objective: The purpose of this report was to present abnormal posttraumatic cold intolerance in patients that previously underwent repair of arterial injuries after civilian upper limb trauma in our institution. Methods: All patients who underwent repair of arterial lesions after upper limb trauma since 1990 were reviewed, and clinical follow-up studies were performed. Patients were asked to complete the cold intolerance symptom severity (CISS) questionnaire to evaluate presence and severity of self-reported cold sensitivity, and the disabilities of arm, shoulder, and hand (DASH) questionnaire to analyze functional disability. Abnormal cold intolerance was defined as a CISS score over 30. Further analysis included evaluation of epidemiologic, clinical, and perioperative data for factors predisposing to abnormal cold intolerance. Results: A total of 87 patients with previous repair of upper limb arterial injuries were eligible to answer the CISS and DASH questionnaires, and 56 patients (64%; 43 men; median age: 31.9 years) completed both. In our cohort, blunt trauma was the predominant cause of injury (n = 50; 89%). Accompanying lesions of nerves (n = 22; 39%) and/or orthopedic injuries (n = 36; 64%) were present in 48 patients (86%). After a median follow-up period of 5.5 years (range, 0.5-19.7), 23 patients (41% of 56) reported on abnormal cold intolerance. Patients with cold intolerance had worse functional results (as measured by the DASH questionnaire; mean ± SD, 42.7 ± 29.7 vs 11.5 ± 23.9; P < .001) when compared with patients without. Cold intolerance was more frequently seen in patients with previous nerve lesion (P = .027) and in proximal injuries (subclavian or axillary vs brachial or forearm arteries: P = .006), but was not correlated to gender, age, involvement of the dominant or nondominant arm, and the presence of ischemia, bone injury, or an isolated vascular injury. Conclusions: Abnormal cold intolerance is frequently seen in patients with a history of arterial repair in upper limb trauma. It is associated with significant functional impairment. Concomitant nerve injury and involvement of the subclavian or axillary artery are the major predisposing factors for development of cold intolerance after upper limb trauma.

Predictors of emergency department death for patients presenting with ruptured abdominal aortic aneurysms - Corrected Proof

2012-05-07

Objective: Ruptured abdominal aortic aneurysm (rAAA) is a critically time-sensitive condition with outcomes dependent on rapid diagnosis and definitive treatment. Emergency department (ED) death reflects the hemodynamic stability of the patient upon arrival and the ability to mobilize resources before hemodynamic stability is lost. The goals of this study were to determine the incidence and predictors of ED death for patients presenting to EDs with rAAAs. Methods: Data for patients presenting with International Classification of Disease, 9th Revision, Clinical Modification codes for rAAA from 2006 to 2008 were extracted from discharge data using the Nationwide Emergency Department Sample (NEDS), Healthcare Cost and Utilization Project, and Agency for Healthcare Research and Quality. The NEDS is the largest stratified weighted sample of US hospital-based ED visits with links to inpatient files. We compared those transferred to those admitted and treated. Sample weights were applied to produce nationally representative estimates. Patient and hospital factors associated with transfer were identified using multivariate logistic regression. These factors were then analyzed for a relationship with ED deaths. Results: A total of 18,363 patients were evaluated for rAAAs. Of these, 7% (1201) died in the ED, 6% (1160) were admitted and died without a procedure, 42% (7731) were admitted and died after repair, and 41% (7479) were admitted, treated, and survived. Transfers accounted for 4% (793) of all ED visits for rAAAs. ED death was more likely for patients seen in nonmetropolitan hospitals (12.7%) vs metropolitan nonteaching (7.0%) or metropolitan teaching hospitals (4.5%; P < .0001). Compared with other regions, the West had a higher ED mortality rate (9.6% vs 5.1%-6.9%; P = .0038). On multivariate analysis, ED death was associated with hospital groups exhibiting both high and low transfer rates. Conclusions: ED death remains a significant cause for mortality for rAAAs and varies by hospital type, rural/urban location, and geographic region. Both delays in ED arrival and delays in providing definitive care may contribute to increased ED death rates, suggesting that improved regional systems of care may improve survival after rAAA.

Regional use of combined carotid endarterectomy/coronary artery bypass graft and the effect of patient risk - Corrected Proof

2012-05-07

Introduction: Although carotid artery stenosis and coronary artery disease often coexist, many debate which patients are best served by combined concurrent revascularization (carotid endarterectomy [CEA]/coronary artery bypass graft [CABG]). We studied the use of CEA/CABG in New England and compared indications and outcomes, including stratification by risk, symptoms, and performing center. Methods: Using data from the Vascular Study Group of New England from 2003 to 2009, we studied all patients who underwent combined CEA/CABG across six centers in New England. Our main outcome measure was in-hospital stroke or death. We compared outcomes between all patients undergoing combined CEA/CABG to a baseline CEA risk group comprised of patients undergoing isolated CEA at non-CEA/CABG centers. Further, we compared in-hospital stroke and death rates between high and low neurologic risk patients, defining high neurologic risk patients as those who had at least one of the following clinical or anatomic features: (1) symptomatic carotid disease, (2) bilateral carotid stenosis >70%, (3) ipsilateral stenosis >70% and contralateral occlusion, or (4) ipsilateral or bilateral occlusion. Results: Overall, compared to patients undergoing isolated CEA at non-CEA/CABG centers (n = 1563), patients undergoing CEA/CABG (n = 109) were more likely to have diabetes (44% vs 29%; P = .001), creatinine >1.8 mg/dL (11% vs 5%; P = .007), and congestive heart failure (23% vs 10%; P < .001). Patients undergoing CEA/CABG were also more likely to take preoperative beta-blockers (94% vs 75%; P < .001) and less likely to take preoperative clopidogrel (7% vs 25%; P < .001). Patients undergoing CEA/CABG had higher rates of contralateral carotid occlusion (13% vs 5%; P = .001) and were more likely to undergo an urgent/emergent procedure (30% vs 15%; P < .001). The risk of complications was higher in CEA/CABG compared to isolated CEA, including increased risk of stroke (5.5% vs 1.2%; P < .001), death (5.5% vs 0.3%; P < .001), and return to the operating room for any reason (7.6% vs 1.2%; P < .001). Of 109 patients undergoing CEA/CABG, 61 (56%) were low neurologic risk and 48 (44%) were high neurologic risk but showed no demonstrable difference in stroke (4.9% vs 6.3%; P = .76), death, (4.9 vs 6.3%; P = .76), or return to the operating room (10.2% vs 4.3%; P = .25). Conclusions: Although practice patterns in the use of CEA/CABG vary across our region, the risk of complications with CEA/CABG remains significantly higher than in isolated CEA. Future work to improve patient selection in CEA/CABG is needed to improve perioperative results with combined coronary and carotid revascularization.

Long segment thoracoabdominal aortic occlusions in childhood - Corrected Proof

Dawn M. Coleman, Jonathan L. Eliason, Richard G. Ohye, James C. Stanley — 2012-05-07

Developmental coarctation, hypoplasia, and occlusion of the abdominal aorta is a rare disease encompassing many differing etiologies and diverse methods of treatment. Long segment thoracoabdominal aortic occlusion, an extreme manifestation of this disorder, has not previously been reported in children. Two pediatric patients with this entity, a 5- and 13-year-old with uncontrolled hypertension, underwent extensive arterial reconstructions for this entity and provided the impetus for this report. An ascending thoracic aorta to infra-renal aortic expanded polytetrafluoroethylene bypass was undertaken in the younger child. A distal thoracic aorto-bi-iliac artery expanded polytetrafluoroethylene bypass, with implantation of the left renal artery to one graft limb and a right renal artery bypass originating from the other limb, was performed in the older child. There were no major perioperative complications. Both patients were discharged with easily controlled blood pressures. They have remained normotensive at 13 and 14 months follow-up.

Implantation of amniotic membrane as a vascular substitute in the external jugular vein of juvenile sheep - Corrected Proof

2012-05-07

Objective: Amniotic membrane, as a natural biomaterial, has many advantages, such as low immunogenicity, anti-inflammation, antifibrosis, and rich extracellular matrix components, which make it a promising source for vascular tissue engineering. This study assessed the feasibility of constructing a vein conduit from the amniotic membrane and implanting it in the external jugular vein of juvenile sheep. Methods: Human amniotic membrane was prepared using fresh human placenta. For construction of a tube such as a vein, the membrane was rolled around a tube and amniotic membrane-constructed conduits were interposed to the external jugular vein by end-to-end anastomosis. Grafts were assessed for patency at weeks 5 and 48 and explanted for evaluation with histologic and microscopic techniques. Results: At 5 weeks after implantation, the grafts were completely patent and displayed no signs of dilation. The internal surface was smooth and shiny, without any evidence of thrombus formation. After 48 weeks, grafts were still completely patent and displayed no signs of intimal thickening, dilation, or stenosis. No inflammation or fibrosis was evident. Histologic evaluation of the explanted grafts demonstrated a monolayer of endothelial cells. Scanning electron microscopy revealed a confluent layer of cells with normal endothelial cell morphology. A monolayer of cells positive for von Willebrand factor was detected in histology sections. Conclusions: The findings of this study confirm that the amniotic membrane can be a proper substitute for vascular tissue engineering. Clinical Relevance: Amniotic membrane is a natural biomaterial that has successfully been used in different fields of surgery. This research evaluated conduit constructed from amniotic membrane as a substitute conduit in the external jugular vein in an animal model. The promising results of this study showed that the amniotic membrane might evolve into a clinically useful alternative for patients lacking vein for vascular reconstructions.

Peritherapeutic quantitative flow analysis of arteriovenous malformation on digital subtraction angiography - Corrected Proof

Tzung-Chi Huang, Tung-Hsin Wu, Chung-Jung Lin, Greta S.P. Mok, Wan-Yuo Guo — 2012-05-07

Background: Digital subtraction angiography (DSA) provides detailed hemodynamic information. However, the imaging interpretation is mainly based on the physician's experience and observation. We aimed to quantitatively study the peritherapeutic blood flow changes of a cerebral arteriovenous malformation (AVM) treated by embolization using optical flow estimation on DSA. Methods: A 37-year-old woman with an AVM in the right frontal lobe of her brain was enrolled. The optical flow method with a pixel-by-pixel measurement was applied to determine the blood flow in brain vessels on anterior–posterior and lateral DSA views before and after embolization. Results: A return toward normalization of blood flow as a result of embolization was determined semiquantitatively on the posttherapeutic DSA. Conclusions: Optical flow analysis on DSA illustrated the potential of quantifying intracranial blood flows in patients with cerebral vascular disorders and the therapeutic effects.

Test characteristics of the ankle-brachial index and ankle-brachial difference for medial arterial calcification on X-ray in type 1 diabetes - Corrected Proof

Joachim H. Ix, Rachel G. Miller, Michael H. Criqui, Trevor J. Orchard — 2012-05-07

Objective: Medial arterial calcification (MAC) is common in diabetes, has a characteristic appearance on X-ray imaging, and has been linked with peripheral arterial stiffness and cardiovascular disease. However, few studies have measured X-ray MAC. It has been suggested that an ankle-brachial index (ABI) >1.30 or an ankle-brachial difference (ABD) >75 mm Hg may identify X-ray MAC, but test characteristics are unknown. We hypothesized that an ABI >1.30 and ABD >75 mm Hg would have high specificity but low sensitivity for MAC on X-ray imaging. Methods: This was a cross-sectional study of 185 community-living individuals with type 1 diabetes. The ABI and the ABD were assessed. The outcome was linear “tram-track” calcifications in the lower limbs characteristic of MAC. Results: Mean age was 32 ± 6 years, and mean diabetes duration was 23 ±7 years. X-ray MAC was noted in 97 individuals (57%), 15 (8%) had ABI >1.30, and 14 (8%) had ABD >75 mm Hg. As assessed by the ABI, the area under the receiver operating characteristic curve for MAC was modest (0.65) and was slightly higher for the ABD (0.75). An ABI >1.30 had high specificity (99%) and positive predictive value (93%) but poor sensitivity (14%) and an overall accuracy of 55% for MAC. An ABD >50 mm Hg remained highly specific (98%) but had higher sensitivity (30%) and overall accuracy (62%). Conclusions: Individuals with type 1 diabetes and an ABI >1.30 or ABD >50 mm Hg are very likely to have MAC on X-ray imaging, yet many with MAC will not have an ABI or ABD above these thresholds. Given the high specificity, evaluating high ABI or ABD may be useful to understand correlates of MAC but may underestimate MAC prevalence.

Prediction of asymptomatic abdominal aortic aneurysm expansion by means of rate of variation of C-reactive protein plasma levels - Corrected Proof

2012-05-03

Objective: C-reactive protein (CRP) is an independent risk factor for arteriosclerosis, but its role in abdominal aortic aneurysm (AAA) expansion remains not completely verified. There are no data about the prognostic significance of rates of variation of the CRP levels in asymptomatic AAAs. This study investigated the association between plasma CRP levels and AAA diameter and assessed the relationship between the gradient of CRP levels and rates of expansion in asymptomatic AAAs. Methods: Plasma levels of high-sensitive CRP (hs-CRP) were measured using a high-sensitivity technique and AAA size was determined by computed tomography in 435 patients with asymptomatic AAAs followed up in our outpatient department. Results: The median hs-CRP level was 4.23 mg/L. The aorta diameter increased in the four groups of patients determined according to hs-CRP quartiles (35 ± 2, 40 ± 3, 49 ± 4, and 58 ± 5 mm; P = .01). The median rate of CRP level variation per year was 1.4 mg/L. Patients with an elevation >1.4 mg/L had an expansion rate of 4.8 mm vs 3.9 mm in those <1.4 mg/L (P < .01). The multivariate age-adjusted logistic model confirmed initial diameter and variation of CRP level were the only factors associated with expansion, with odds ratios (95% confidence intervals) of 6.3 (3.1-7.5) and 3.4 (2.1-5.6). Conclusions: These results confirm a statistical association between AAA diameter and hs-CRP plasma levels. This cohort study corroborates this potential causal association and contributes information about the value of the hs-CRP plasma level gradient as a marker of disease progression and rate of expansion.

Combination therapy with warfarin plus clopidogrel improves outcomes in femoropopliteal bypass surgery patients - Corrected Proof

2012-05-03

Background: Patients having undergone femoropopliteal bypass surgery remain at significant risk of graft failure. Although antithrombotic therapy is of paramount importance in these patients, the effect of oral anticoagulation therapy (OAT) on outcomes remains unresolved. We performed a randomized, prospective study to assess the impact of OAT plus clopidogrel vs dual antiplatelet therapy on peripheral vascular and systemic cardiovascular outcomes in patients who had undergone femoropopliteal bypass surgery. Methods: Three hundred forty-one patients who had undergone femoropopliteal surgery were enrolled and randomized: 173 patients received clopidogrel 75 mg/d plus OAT with warfarin (C + OAT), and 168 patients received dual antiplatelet therapy with clopidogrel 75 mg/d plus aspirin 100 mg/d (C + acetylsalicylic acid [ASA]). Study end points were graft patency and the occurrence of severe peripheral arterial ischemia, and the incidence of bleeding episodes. Results: Follow-up ranged from 4 to 9 years. The graft patency rate and the freedom from severe peripheral arterial ischemia was significantly higher in C + OAT group than in C + ASA group (P = .026 and 0.044, respectively, Cox-Mantel test). The linearized incidence of minor bleeding complications was significantly higher in C + OAT group than in C + ASA group (2.85% patient-year vs 1.37% patient-year; P = .03). The incidence of major adverse cardiovascular events, including mortality, was found to be similar (P = .34) for both study groups. Conclusions: In patients who have undergone femoropopliteal vascular surgery, combination therapy with clopidogrel plus warfarin is more effective than dual antiplatelet therapy in increasing graft patency and in reducing severe peripheral ischemia. These improvements are obtained at the expenses of an increase in the rate of minor anticoagulation-related complications.

The role of open and endovascular treatment with fenestrated and chimney endografts for patients with juxtarenal aortic aneurysms - Corrected Proof

2012-05-03

Objective: To present endovascular techniques in the treatment of juxtarenal aortic aneurysms (JAAAs) in relation to surgical repair; this is the “gold standard.” Methods: Between January 2008 and December 2010, 90 consecutive patients were diagnosed with primary degenerative JAAAs (≥5.0 cm) and assigned prospectively to different operative strategies on the basis of morphologic and clinical characteristics. In particular, 59 patients were treated by endovascular means such as fenestrated endovascular abdominal aortic repair (f-EVAR, n = 29) or chimney endovascular abdominal aortic repair (ch-EVAR, n = 30) endografting, and 31 patients underwent open repair (OR, n = 31). Results: Early procedure-related and all-cause (30-day) procedure-related mortality was 0% for the endovascular group and 6.4% (n = 2/31) for the OR group, due to systemic inflammatory response syndrome with consecutive multi-organ failure (P = .023). Persistent postoperative hemodialysis occurred only after OR (2/31; 6.4%). The overall estimated pre- and postoperative median estimated glomerular filtration rate and creatinine values were similar in the three subgroups. There was one left renal artery occlusion for each endovascular subgroup presented with flank pain and treated by iliaco-renal bypass in both cases. Transfusion requirements and length of hospital stay were significantly less in the endovascular group (P = .014 and P = .004, respectively). Conclusions: Endovascular treatment of JAAA is a safe alternative for the short-term management of JAAA.

Hemodynamic conditions in a failing peripheral artery bypass graft - Corrected Proof

2012-05-03

Objective: The mechanisms of restenosis in autogenous vein bypass grafts placed for peripheral artery disease are not completely understood. We investigated the role of hemodynamic stress in a case study of a revised bypass graft that failed due to restenosis. Methods: The morphology of the lumen was reconstructed from a custom three-dimensional ultrasound system. Scans were taken at 1, 6, and 16 months after a patch angioplasty procedure. Computational hemodynamic simulations of the patient-specific model provided the blood flow features and the hemodynamic stresses on the vessel wall at the three times studied. Results: The vessel was initially free of any detectable lesions, but a 60% diameter-reducing stenosis developed during the 16-month study interval. As determined from the simulations, chaotic and recirculating flow occurred downstream of the stenosis due to the sudden widening of the lumen at the patch location. Curvature and a sudden increase in the lumen cross-sectional area induced these flow features that are hypothesized to be conducive to intimal hyperplasia. Favorable agreement was found between simulation results and in vivo Doppler ultrasound velocity measurements. Conclusions: Transitional and chaotic flow occurs at the site of the revision, inducing a complex pattern of wall shear as computed with the hemodynamic simulations. This supports the hypothesis that the hemodynamic stresses in the revised segment, produced by the coupling of vessel geometry and chaotic flow, led to the intimal hyperplasia and restenosis of the graft.

Small skin incision and fistula elevation for hemodialysis using the femoral vein - Corrected Proof

Francisco Alcocer, Saul Perez, Camilo Martinez — 2012-05-03

Background: Wound morbidity commonly accompanies transposition of the femoral vein when used for hemodialysis access, mainly because of the length of the skin incision. A short incision may reduce wound complications but may compromise the arteriovenous (AV) function because of the shorter length of femoral vein available for puncture. This report presents our experience with a modification of the original technique, in which a smaller skin incision and fistula elevation were used. Methods: The clinical course of 25 AV fistulas in the thigh using the femoral vein was retrospectively analyzed. The original technique to create femoral AV access was used in 12 patients and the modified technique in 13. The procedures were performed between 2005 and 2007, and patients were monitored until January 31, 2011. Results: Three fistulas failed in each group. Five patients in the original group had wound complications. No wound complications occurred in the modified group. The fistula was first used at an average of 10.45 weeks and 6.14 weeks, respectively. Patency was similar in both groups. Conclusions: It is possible to obtain a functional AV fistula in the thigh using the femoral vessels and limiting the extent of the incision. Long-term patency is reasonable, despite the use of a short femoral segment for puncture.

Negative pressure wound therapy on exposed prosthetic vascular grafts in the groin - Corrected Proof

Paul Berger, Dennis de Bie, Frans L. Moll, Gert-Jan de Borst — 2012-05-03

Objective: This study assessed the outcome of vacuum-assisted closure (VAC) as primary therapy for exposed prosthetic vascular grafts in the groin (Szilagyi III). Methods: The study included all consecutive patients with Szilagyi III groin infections and exposed prosthetic graft material from 2009 to 2011. After initial wound debridement, VAC was applied using a two-layer combination, consisting of polyvinyl alcohol and polyurethane sponges. Continuous negative pressure was set on a maximum of 50 mm Hg. All patients received complementary antibiotic therapy. The primary endpoint was defined as complete wound closure. Secondary endpoints comprised bleeding complications, amputation, and death. Results: The study evaluated 15 patients with 17 Szilagyi III groin infections. Mean total length of VAC therapy was 43 days (range, 14-76 days). Mean time until complete healing was 51 days (range, 24-82 days). Mean length of VAC therapy in the hospital was 21 days (range, 5-61 days). Eleven patients received continued VAC treatment at home for a mean length of 22 days (range, 5-69 days). Complete healing was achieved in 14 groins (82%). Three failures due to persisting infection, persisting necrosis, and a pseudomonas infection were noted. No bleeding complications, amputations, or late reinfections occurred. Median follow-up was 380 days (range, 56-939 days). Despite therapy failure, all 17 grafts were preserved. Conclusions: VAC therapy on an exposed prosthetic vascular graft in the groin is safe and feasible when applying a combination of polyvinyl alcohol and polyurethane foam dressing and 50 mm Hg of continuous negative pressure, resulting in midterm graft preservation.

Physician-modified endovascular grafts for the treatment of elective, symptomatic, or ruptured juxtarenal aortic aneurysms - Corrected Proof

Benjamin W. Starnes — 2012-05-03

Objective: To determine if a physician-modified endovascular graft (PMEG) is a safe and effective method of treating juxtarenal aortic aneurysms in patients considered to be unsuitable for open surgical repair. Methods: A retrospective, nonrandomized, single institution evaluation of the safety and efficacy of physician modification of a currently Food and Drug Administration-approved device (Zenith Flex; Cook Inc, Bloomington, Ind) to preserve branch vessels when used in the treatment of patients with elective, symptomatic, or ruptured juxtarenal aortic aneurysms. Results: Forty-seven consecutive patients underwent fenestrated endovascular repair using PMEG over a 3-year period. Thirty-eight patients (80%) were symptomatic or had rapid aneurysm expansion. Eighty-five percent of patients were American Society of Anesthesiologist category III or IV. Eight-two fenestrations were created for 58 renal arteries, 16 superior mesenteric arteries, three celiac arteries, and the rest accessory vessels. Mean follow-up was 607 days, with a range of 425 to 1460 days. Mean contrast usage and fluoro time were 98 mL and 48 minutes. Technical success rate was 98%, and freedom from aneurysm-related death was 98%. There were six complications (13%). Three (6%) were access related, and three (6%) were procedure related and included one stroke, one case of renal failure, and one branch artery dissection. On follow up, six patients (13%) had endoleak. There was one Type 1 endoleak and five Type 2 endoleaks. In-hospital and 30-day mortality was 2%, with one patient expiring due to aspiration on the ward after successful endovascular repair. Two patients died during follow-up; one at 58 days due to cessation of dialysis and one at 485 days due to stent graft migration and occlusion of the superior mesenteric artery. There were two deaths in the first year, one in the second year, and zero in the most recent year of experience. One patient with endoleak (2%) had aneurysm sac expansion at 1 year requiring secondary intervention. Conclusions: PMEG is a safe and effective alternative for treating patients with juxtarenal aneurysms who have no other alternatives for repair. Longer-term follow-up is needed to assess the durability of repair and potential for device-related complications.

Eight-year follow-up of endovascular repair of a brachiocephalic trunk aneurysm due to Takayasu's arteritis - Corrected Proof

2012-05-03

Aneurysms of the brachiocephalic trunk are rare but their clinical outcomes are potentially devastating; they include rupture, cerebral or arm ischemia secondary to thromboembolism, and compression of the surrounding structures. Although open repair has proven successful, it is associated with significant morbidity and mortality rates. Endovascular treatment, if anatomically feasible, may offer a safer and less invasive approach to these lesions, especially in high-surgical-risk patients. We report the good long-term outcome of endovascular repair of a large innominate artery true aneurysm due to Takayasu's arteritis. A stent graft was safely and successfully deployed to exclude the aneurysm; assessment by vascular imaging at 8-year follow-up demonstrated the efficacy of the procedure.

An integrated biochemical prediction model of all-cause mortality in patients undergoing lower extremity bypass surgery for advanced peripheral artery disease - Corrected Proof

2012-05-03

Background: Patients with advanced peripheral artery disease (PAD) have a high prevalence of cardiovascular (CV) risk factors and shortened life expectancy. However, CV risk factors poorly predict midterm (<5 years) mortality in this population. This study tested the hypothesis that baseline biochemical parameters would add clinically meaningful predictive information in patients undergoing lower extremity bypass operations. Methods: This was a prospective cohort study of patients with clinically advanced PAD undergoing lower extremity bypass surgery. The Cox proportional hazard model was used to assess the main outcome of all-cause mortality. A clinical model was constructed with known CV risk factors, and the incremental value of the addition of clinical chemistry, lipid assessment, and a panel of 11 inflammatory parameters were investigated using the C statistic, the integrated discrimination improvement index, and Akaike information criterion. Results: The study monitored 225 patients for a median of 893 days (interquartile range, 539-1315 days). In this study, 50 patients (22.22%) died during the follow-up period. By life-table analysis (expressed as percent surviving ± standard error), survival at 1, 2, 3, 4, and 5 years, respectively, was 90.5% ± 1.9%, 83.4% ± 2.5%, 77.5% ± 3.1%, 71.0% ± 3.8%, and 65.3% ± 6.5%. Compared with survivors, decedents were older, diabetic, had extant coronary artery disease, and were more likely to present with critical limb ischemia as their indication for bypass surgery (P < .05). After adjustment for the above, clinical chemistry and inflammatory parameters significant (hazard ratio [95% confidence interval]) for all-cause mortality were albumin (0.43 [0.26-0.71]; P = .001), estimated glomerular filtration rate (0.98 [0.97-0.99]; P = .023), high sensitivity C-reactive protein (hsCRP; 3.21 [1.21-8.55]; P = .019), and soluble vascular cell adhesion molecule (1.74 [1.04-2.91]; P = .034). Of the inflammatory molecules investigated, hsCRP proved most robust and representative of the integrated inflammatory response. Albumin, eGFR, and hsCRP improved the C statistic and integrated discrimination improvement index beyond that of the clinical model and produced a final C statistic of 0.82. Conclusions: A risk prediction model including traditional risk factors and parameters of inflammation, renal function, and nutrition had excellent discriminatory ability in predicting all-cause mortality in patients with clinically advanced PAD undergoing bypass surgery.