Patient and procedure-related risk factors for adverse events after infrainguinal bypass
Article Outline
Background
Current medical practice urges individual health care facilities and medical professionals to obtain and provide detailed insight in quality of care with the possibility of comparing data between institutions. Adverse event (AE) analysis serves as a mainstay in quality assessment in vascular surgery, but the comparison of AE data between facilities can be complex. The aim of the present study was to assess independent risk factors for AE occurrence: patient, disease and operation characteristics besides general differences between health care facilities.
Methods
All AEs after infrainguinal bypass graft procedures (BGPs) in three health care facilities in the Netherlands were evaluated. AEs were defined identically in the facilities.
Results
Of 601 BGPs performed, 662 AEs were registered. Independent predictors of AEs were female gender (odds ratio [OR], 2.13; 95% confidence interval [CI], 1.39-3.26; P < .01), age ≥60 years (OR, 0.57; 95% CI, 0.34-0.95; P = .03), American Society of Anesthesiologists classification 3-4 (OR, 1.79; 95% CI, 1.01-3.17; P = .05), comorbidities of pulmonary disease (OR, 2.99; 95% CI, 1.67-5.34; P < .01) and diabetes mellitus (OR, 2.49; 95% CI, 1.58-3.94; P < .01), distal anastomosis level at below knee femoropopliteal BGP (OR, 2.01; 95% CI, 1.26-3.22; P < .01), femorotibial BGP (OR, 2.40; 95% CI, 1.37-4.19; P < .01), and popliteopedal BGP (OR, 92.39; 95% CI, 11.13-766.98; P < .01). One health care facility had significantly fewer AEs than the other two (OR, 0.21; 95% CI, 0.13-0.35; P < .01).
Conclusion
Age, gender, comorbidity, and type of surgery are all independent predictors of AE occurrence in vascular surgery. After adjustment for differences in these factors, one health care facility still had lower AE occurrence, which needs to be examined further.
The current medical climate, characterized by increased cost, individual patient awareness, and medicolegal concerns, urges individual health care facilities and medical professionals to obtain and provide detailed insight in the quality of provided care. To evaluate provided care, analyses of process, structure, and outcome indicators are frequently reported.1, 2 One of the most studied outcome indicators is the assessment of incidences of adverse events (AEs).
Evaluating AEs can raise the awareness of shortcomings in surgical practice and increase transparency in provided care. Through analysis of AEs, one can learn from them, and through study of the cause of the occurrence of the AEs, one can try to decrease the number and severity of AEs in the future.3, 4, 5 Therefore, AEs can be used as outcome measures to assess the quality of surgical care.6, 7, 8
Owing to extensive comorbid conditions and technically challenging surgical revascularization procedures, patients treated for peripheral arterial occlusive disease (PAOD) are at high risk for developing AEs. Rutherford et al9, 10 proposed an AE registration classification. However, the literature shows inconsistency in defining, documenting, and classifying AEs, resulting in diverse interpretations of AE analysis.8, 11, 12
The Association of Surgeons of the Netherlands (ASN)13 developed a uniform definition of an AE. Three teaching hospitals in the Netherlands—the Department of Vascular Surgery of the St. Elisabeth Hospital in Tilburg (EH),3, 8, 14 the Red Cross (RCH) and the Leyweg locations in The Hague of the Haga Hospital,4, 5, 6, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 and the Leiden University Medical Centre (LUMC)13, 25, 26, 27—used this definition and have been documenting AEs prospectively according to this definition for >15 years.
The aim of the present study was to assess the independent risk factors for AE occurrence after peripheral arterial bypass graft procedures (BGP) of patient, disease, and operation characteristics besides general differences between health care facilities.
Methods
Patients
Between January 2000 and January 2005, 601 consecutive patients were treated with a BGP for PAOD at the surgical departments of the EH, the RCH, and in the LUMC in the Netherlands. These three health care facilities are teaching hospitals. Criteria for treatment were intermittent claudication (IC) or critical lower limb ischemia (CLI). IC was defined as extremity pain, discomfort, or weakness that is consistently produced by the same amount of walking or equivalent muscular activity in a given patient and that is promptly relieved by cessation of that activity with a pain-free walking distance (PFWD) <100 m and an ankle pressure after exercise <50 mm HG (Fontaine stage IIb). This corresponds with category 3 of the Society for Vascular Surgery/North American Chapter of the International Society for Cardiovascular Surgery (SVS/ISCVS) standards.9, 10 CLI was defined as ischemic rest pain (Fontaine classification 3) with a resting ankle pressure <40 mm Hg and gangrene or nonhealing ischemic ulceration (Fontaine classification 4) with a resting ankle pressure <60 mm Hg. This corresponds with categories 4, 5, and 6 of the SVS/ISCVS standards.
Risk factors and comorbidities
Risk factors and comorbidities were registered prospectively of all patients during their admission intake. Smoking, hypertension, cardiac disease, hyperlipidemia, diabetes mellitus, renal disease, pulmonary disease, carotid disease, and age were classified according to the SVS/ISCVS standards and according to the Trans-Atlantic InterSociety Consensus Document on Management of Peripheral Arterial Disease (TASC).28 Risk factor and comorbidity management, according to TASC and the American Heart Association/American College of Cardiology (AHA/ACC),29 were conducted by a vascular specialist or cardiologist preoperatively in the out-patient clinic or during admission before operation when an urgent intervention was indicated. The American Society of Anesthesiologists (ASA) classification30 of patients was determined according to their general preoperative condition prospectively.
Revascularization
Vascular treatment by infrainguinal BGPs was performed according to standard vascular techniques, using preferably reversed vein for infrainguinal femoropopliteal, crural, or pedal BGPs. All vascular operations were performed by or under the supervision of a vascular surgeon. The decision to intervene and the type of intervention were driven by the SVS/ISCVS and TASC reporting standards.
Adverse events
The Association of Surgeons of the Netherlands (ASN) has agreed on a common definition of AEs.13, 26, 31 This definition differs from that used in other studies because it was chosen with the explicit aim of excluding subjective judgment on cause and effect, and right and wrong. The definition of an AE is:
An unintended and unwanted event or state occurring during or following medical care, that is so harmful to a patient's health that (adjustment of) treatment is required or that permanent damage results. The AE may be noted during hospitalization, until 30 days after discharge or transfer to another department. The intended result of treatment, the likelihood of the adverse outcome occurring, and the presence or absence of a medical error causing it, is irrelevant in identifying an adverse outcome.
All three health care facilities registered AEs according to this definition.
Statistical analysis
Patients with and without AE were compared on several characteristics using χ2 tests. If the expected count of a variable was less than five, the Fisher-exact test was used. This was done both for patient characteristics (age, gender), disease/health status of the patient (ASA, PAOD), comorbidity (cardiac, pulmonary, renal, carotid disease, diabetes mellitus), tobacco use, and type of bypass procedure. We also included a variable of the hospital where patients were treated to take into account any remaining variation.
The variables showing significant differences between patients with and without AEs were included in the multivariable logistic regression analysis with AE occurrence as the dependent variable. The same analysis was done with specific types of AEs as the dependent variable to assess whether these were risk factors for specific types of AEs or for AEs in general. In addition to this full model including all variables, we also assessed whether a limited model would fit the data just as well, including only those variables readily available in most registries. This will give some estimate about whether the additional effort of collecting extra information, as done in the present study, is worthwhile. The Nagelkerke R2 was used as a measure of the goodness-of-fit, indicating the percentage of the variance in AE occurrence that is explained by the variables included in the model.
For all statistical analyses, a value of P < .05 was considered statistically significant. Statistical analyses were performed using SPSS 16.0 software (SPSS Inc, Chicago, Ill).
Results
Patients and AE
During the study period, 371 men (61.7%) and 230 women (38.3%) underwent surgical treatment because of PAOD. Mean age was 72.6 years (range, 35-94 years). AEs were prospectively reported in 283 patients (47.3%) during the 30-day postoperative period, with a total of 662 AEs (Table I). Most AEs concerned the (sub)cutis (31.4%), vascular management (23.4%), or the cardiac system (12.4%).
Table I. Adverse events (n = 662) after treatment for peripheral arterial occlusive disease in the sample of 601 patients
| Adverse events | No. (%) |
|---|---|
| Cardiac | 82 (12.4) |
| Congestive heart failure | 31(4.7) |
| Arrhythmia | 12(1.8) |
| Cardiac arrest | 8(1.2) |
| Myocardial infarction | 26(3.9) |
| Tachycardia/bradycardia | 3(0.5) |
| Endocarditis/pericarditis | 1(0.2) |
| Other | 1(0.2) |
| Pulmonary | 27(4.1) |
| Respiratory insufficiency | 6(0.9) |
| Aspiration/pneumonia | 21(3.2) |
| Neurology | 20(3.0) |
| Cerebrovascular accident | 6(0.9) |
| Neurapraxia | 4(0.6) |
| Other | 10(1.5) |
| Renal | 39(5.9) |
| Renal failure | 9(1.4) |
| Urinary tract infection | 18(2.7) |
| Urinary retention | 12(1.8) |
| (Sub)cutis | 208(31.4) |
| Blister or ulcer | 11(1.7) |
| Abscess | 16(2.4) |
| Seroma | 7(1.1) |
| Cellulites | 8(1.2) |
| Wound hematoma | 10(1.5) |
| Wound infection | 98(14.8) |
| Wound dehiscence | 21(3.2) |
| Necrosis or tissue loss | 37(5.6) |
| Muscles and skeleton | 5(0.8) |
| Compartmental syndrome | 3(0.5) |
| Osteomyelitis | 2(0.3) |
| Hematology | 28(4.2) |
| Thrombocytopenia | 3(0.5) |
| Septicemia | 20(3) |
| Fluid and electrolytes | 5(0.8) |
| Vascular management | 155(23.4) |
| Line infection | 5(0.8) |
| Deep venous thrombosis | 3(0.5) |
| Bypass graft procedure | |
| Infection | 6(0.9) |
| Stenosis | 12(1.8) |
| Occlusion | 81(12.2) |
| Hemorrhage | 48(7.3) |
| General management | 98(14.8) |
| Error in (Appendix 3) | 27(4.1) |
| Delay in (Appendix 3) | 48(7.3) |
| Incomplete hospital record | 23(3.5) |
| Total adverse events | 662(100) |
| Patients with adverse events | 283(47.3) |
Risk factors of AEs
As summarized in Table II, patients with AEs more often were women, <60 years of age, at ASA ≥3, treated for CLI, had cardiac, pulmonary, renal, carotid disease, or diabetes mellitus, were smokers, and underwent a below knee BGP. Fewer patients with AEs were treated in health care facility 2 than in the other two. This was confirmed in multivariable analysis that showed the independent risk factors for AE occurrence were female gender, age <60 years, ASA 3 or 4, pulmonary disease, diabetes mellitus, and all three below knee BGPs (Table III). Furthermore, health care facility 2 had significantly lower AE occurrence after adjustment for the above differences in patient, disease, and operation characteristics. This full model, including all of these variables, fit the data rather well, explaining 44% of the variance in AE occurrence (Table III).
Table II. Differences in patient, disease, and procedure characteristics between patients with and without adverse events
| Characteristics, % | Without AEs (n = 318) | With AEs (n = 283) | Test of difference | |
|---|---|---|---|---|
| χ2 | P | |||
| Gender | 6.11 | .01 | ||
| Male | 66.4 | 56.5 | ||
| Female | 33.6 | 43.5 | ||
| Age, % | 4.17 | .04 | ||
| ≥60 years | 83 | 76.3 | ||
| ASA classification | 94.97 | <.01 | ||
| 1-2 | 69.5 | 29.7 | ||
| 3-4 | 30.5 | 70.3 | ||
| PAOD, % | 21.83 | <.01 | ||
| Intermittent claudication | 38.4 | 20.8 | ||
| Critical limb ischemia | 61.6 | 79.2 | ||
| Comorbidity (SVS/ISCVS) | ||||
| Cardiac disease | 38.46 | <.01 | ||
| No | 63.8 | 38.5 | ||
| Yes | 36.2 | 61.5 | ||
| Pulmonary disease | 27.38 | <.01 | ||
| No | 89.6 | 73.1 | ||
| Yes | 10.4 | 26.9 | ||
| Renal disease | 6.22 | .01 | ||
| No | 95.6 | 90.5 | ||
| Yes | 4.4 | 9.5 | ||
| Carotid disease | 8.43 | <.01 | ||
| No | 89.3 | 80.9 | ||
| Yes | 10.7 | 19.1 | ||
| Diabetes mellitus | 34.47 | <.01 | ||
| No | 77.7 | 55.1 | ||
| Yes | 22.3 | 44.9 | ||
| Tobacco use | 5.98 | .01 | ||
| No | 48.4 | 38.5 | ||
| Yes | 51.6 | 61.5 | ||
| Bypass graft procedure | 61.56 | <.01 | ||
| Femoropopliteal, AK | 51.9 | 27.9 | ||
| Femoropopliteal, BK | 31.8 | 36.7 | ||
| Femorotibial | 16 | 23.3 | ||
| Popliteopedal | 0.3 | 12 | ||
| Health care facility | 88.76 | <.01 | ||
| Facility 1 | 22.3 | 48.8 | ||
| Facility 2 | 62.9 | 24.7 | ||
| Facility 3 | 14.8 | 26.5 | ||
Table III. Determinants for adverse event occurrence: multivariate analysis (full model)a
| Characteristics | OR | 95% CI | Pb |
|---|---|---|---|
| Gender | |||
| Female vs male | 2.13 | (1.39-3.26) | <.01 |
| Age | |||
| Age ≥60 vs <60 years | 0.57 | (0.34-0.95) | .03 |
| ASA classification | |||
| 3-4 vs 1-2 | 1.79 | (1.01-3.17) | .05 |
| PAOD | |||
| CLI vs IC | 0.68 | (0.40-1.16) | .16 |
| Comorbidity (SVS/ISCVS) | |||
| Cardiac disease (yes/no) | 1.62 | (0.97-2.68) | .06 |
| Pulmonary disease (yes/no) | 2.99 | (1.67-5.34) | <.01 |
| Renal disease (yes/no) | 1.31 | (0.55-3.12) | .54 |
| Carotid disease (yes/no) | 1.67 | (0.94-2.97) | .08 |
| Diabetes mellitus (yes/no) | 2.49 | (1.58-3.94) | <.01 |
| Tobacco use (yes/no) | 1.32 | (0.86-2.02) | .2 |
| Bypass graft procedure | |||
| (Ref = Femoropopliteal, AK) | |||
| Femoropopliteal, BK | 2.01 | (1.26-3.22) | <.01 |
| Femorotibial | 2.4 | (1.37-4.19) | <.01 |
| Popliteopedal | 92.39 | (11.13-766.98) | <.01 |
| Health care facility | |||
| (Ref = Facility 1) | |||
| Facility 2 | 0.21 | (0.13-0.35) | <.01 |
| Facility 3 | 1.14 | (0.66-1.98) | .63 |
aModel fit: Nagelkerke R2 = 0.44. |
bValues of P < .05 are significant. |
If only age, gender, ASA class, type of BGP, and hospital were included in the multivariable analysis, because these are readily available in most registries, similar results were found except for the higher risk associated with ASA class 3 and 4 (Table IV). It is likely that part of the comorbidity is now included in the higher ASA classes, resulting in a higher excess risk. With such a limited model, including only variables readily available in most registries, still a rather good fit of the data is obtained, explaining 39% of the variance in AE occurrence by this limited set of variable (Table IV).
Table IV. Determinants for adverse event occurrence: multivariate analysis (limited model)a
| Characteristics | OR | 95% CI | Pb |
|---|---|---|---|
| Gender | |||
| Female vs male | 2 | (1.33-3.01) | <.01 |
| Age | |||
| Age ≥60 vs <60 years | 0.47 | (0.29-0.76) | <.01 |
| ASA classification | |||
| 3-4 vs 1-2 | 3.38 | (2.26-5.07) | <.01 |
| Bypass graft procedure | |||
| (Ref = Femoropopliteal, AK) | |||
| Femoropopliteal, BK | 1.82 | (1.17-2.84) | <.01 |
| Femorotibial | 2.52 | (1.50-4.22) | <.01 |
| Popliteopedal | 78.06 | (9.89-616.16) | <0.01 |
| Health care facility | |||
| (Ref = Facility 1) | |||
| Facility 2 | 0.27 | (0.17-0.44) | <.01 |
| Facility 3 | 1.2 | (0.72-1.99) | .48 |
aModel fit: Nagelkerke R2 = 0.39. |
bValues of P < .05 are significant. |
To assess whether these risk factors were found for all types of AEs or just for specific groups, the same analyses were performed for the largest groups of AEs in Table I, comprising cardiac, (sub)cutis, and vascular management. Gender and ASA classification were not found as independent risk factors for these three AE groups (data not shown). The lower AE occurrence in patients aged >60 years was only found for vascular management AEs (odds ratio [OR], 0.43; 95% confidence interval [CI], 0.24-0.77). Diabetes mellitus on the other hand, consistently increased the incidence in all three groups of AEs (cardiac: OR, 2.37 [95% CI, 1.20-4.67]; (sub)cutis: OR, 2.44 [95% CI, 1.58-3.77]; vascular management: OR, 2.38 [95% CI, 1.42-3.96]), as did smoking (cardiac: OR, 2.40 [95% CI, 1.03-5.58]; (sub)cutis: OR, 1.69 [95% CI, 1.06-2.67]; vascular management: OR, 2.06 [95% CI, 1.18-3.60]). Pulmonary comorbidity was only found to increase the occurrence of cardiac AEs (OR, 4.58; 95% CI, 2.21-9.51). The incidence of vascular management AEs was increased in all three below knee BGPs compared with above knee BGP (femoropopliteal BGP: OR, 2.06 [95% CI, 1.11-3.83]; femorotibial BGP: OR, 3.23 [95% CI, 1.64-6.38]; popliteopedal BGP: OR, 16.74 [95% CI, 6.43-43.60]) .The incidence of (sub)cutis AEs was only increased for popliteopedal BGP (OR, 3.02 [95% CI, 1.29-7.05]). Health care facility 2 had consistently lower occurrences in all three AE groups (cardiac: OR, 0.20 [95% CI, 0.08-0.51]; (sub)cutis: OR 0.40 [0.24-0.69]; vascular management: OR, 0.33 [0.18-0.62]).
Discussion
The primary goal of this study was to assess independent risk factors for AE occurrence after peripheral arterial BGP: patient, disease, and operation characteristics besides general differences between health care facilities.
In this study, 661 AEs were registered in 601 patients, and one or more AEs were documented in 47% of all patients undergoing BGP. As expected, patients undergoing peripheral arterial BGP frequently have extensive comorbid conditions resulting in a relatively high likelihood to experience AEs. In accordance with previous reports, the specific patient population in our study frequently experienced wound, graft, and cardiac AEs.4, 18, 32
Specific detailed analysis of variables related to the occurrence of AEs was conducted. Especially, differences in patient, disease, and procedural characteristics, as well as differences between health care facilities, were assessed in terms of likelihood of AEs. When patients with and without AEs were compared by univariate analysis, female gender, age <60 years, indication of operation (CLI vs IC) and comorbid conditions were related to AE occurrence. The type of operation performed was also strongly related with the incidence of AEs. Patients undergoing distal BGP were highly susceptible to AEs, with almost no patients without AEs during admission.
In multivariate analysis, female gender, age, pulmonary disease, and diabetes mellitus were independent predictive risk factors for the occurrence of AEs. The type of operation performed was also strongly related to the incidence of AEs; this result is in concordance with the literature especially in patients undergoing distal bypasses.33
After adjustment for differences in these characteristics, patients treated in health care facility 2 had a lower AE occurrence than patients from the other hospitals. Similar results occurred when only limited information readily available in most registries was included and also fitted the data rather well, explaining 39% instead of 44% of the variance. The lower AE occurrence in health care facility 2 was found for cardiac, (sub)cutis, and vascular management AEs. Diabetes mellitus,34, 35, 36, 37, 38 smoking,37, 38, 39, 40 and popliteopedal34, 35, 37, 38 BGP also increased the occurrence for all three types of AE, as is well known from the literature.
The results may partially be explained by factors not taken into account in this study. Not only are preoperative comorbid conditions strongly associated with AEs but also operations in patients undergoing previous vascular procedures in the unilateral limb.34, 41 Therefore, detailed registration of previous vascular interventions in the affected limb should be documented. Furthermore, emergency operations are associated with more AEs compared with elective cases,6, 21, 42, 43 as well as a possible difference in AE occurrence between open and endovascular procedures as a the primary choice of treatment. These factors, which were not measured in this study, might explain part of the lower AE occurrence in health care facility 2, if this facility were, for instance, to treat more patients undergoing primary revascularization instead of redo procedures or were to have a different mix in open and endovascular procedures.
Our results show that one health care facility had a lower AE occurrence after adjustment for several patient, disease, comorbidity, and operation characteristics. The question is whether the occurrence of AEs is actually lower or was caused by higher under-reporting or a different interpretation of the AE definition in this facility. For instance, a difference in reported wound infections (as one of the possible AEs) could be caused by interobserver variability among different physicians in different facilities (local skin redness observed depends on day to day wound inspection) and variability of interhealth care facility therapeutically prophylactic strategies (local skin redness postoperatively treated with prophylactic antibiotics more readily in one facility compared with another facility). These factors are not easily measured by objective variables but may explain a significant part of the observed difference between health care facilities.
These results can be used in clinical practice. The identification of risk factors for postoperative AEs is essential to balance the potential benefits and risks of surgical interventions in individual patients. A detailed insight in the chances of an unfavorable outcome by assessing AE incidences (and therefore ones' own medical performance) in the past is paramount to choosing the appropriate surgical strategy and to provide future patients with proper information about the risk of postoperative AEs given the possible risk factors that these patients may have.1
A possible implication of these findings is observed differences in AE occurrence between health care facilities may represent true differences, may be caused by other (unmeasured) factors, or may be induced by subtle differences in the interpretation of the same definition. One of the possibilities is to engage a team of independent reviewers to audit a sample of the medical records of patients with and without AEs to assess whether all health care facilities interpret the definition in exactly the same way and have similar effectiveness in reporting these AEs. Only then will the study of AE differences between facilities and other factors associated with quality of care do what it was initiated for in the first place: contribute to the improvement of quality of care.
Conclusion
Comparison of quality of care among different health care facilities after arterial peripheral bypass surgery by assessing AE incidences is complex. Patient and disease characteristics, comorbidity, and type of surgery performed are independent risk factors for AE occurrence. If corrected for these variables, significant differences still exist between different health care facilities in AE incidence.
Author contributions
References
- . Decrease of mortality of ruptured abdominal aortic aneurysm after centralization and in-hospital quality improvement of vascular service. Ann Vasc Surg. 2007;21:580–585
- . Use of national surgical quality improvement program data as a catalyst for quality improvement. J Am Coll Surg. 2007;204:1293–1300
- . Classifying surgical complications: a critical appraisal. Arch Surg. 2005;140:1078–1083
- . Complication registration in patients after peripheral arterial bypass surgery. Ann Vasc Surg. 2003;17:198–202
- . Recording and classification of complications in a surgical practice. Eur J Surg. 1999;165:421–424discussion 425
- . Can the incidence of unplanned reoperations be used as an indicator of quality of care in surgery?. Am J Med Qual. 2007;22:198–202
- . Quality of health care (Part 3: Improving the quality of care). N Engl J Med. 1996;335:1060–1063
- . The registration of complications in surgery: a learning curve. World J Surg. 2005;29:402–409
- . Vascular surgery—comparing outcomes. J Vasc Surg. 1996;23:5–17
- Recommended standards for reports dealing with lower extremity ischemia: Revised version. J Vasc Surg. 1997;26:517–538
- . Complications on a general surgery service: Incidence and reporting. Can J Surg. 2000;43:113–117
- . Quality of complication reporting in the surgical literature. Ann Surg. 2002;235:803–813
- . Effectiveness of routine reporting to identify minor and serious adverse outcomes in surgical patients. Qual Saf Health Care. 2005;14:378–382
- . [registration of postoperative complications to improve the results of surgery]. Ned Tijdschr Geneeskd. 1996;140:781–784
- . Skin closure after infrainguinal bypass surgery: a prospective randomised study. Eur J Vasc Endovasc Surg. 2002;23:321–324
- . Vein versus polytetrafluoroethylene in above-knee femoropopliteal bypass grafting: five-year results of a randomized controlled trial. J Vasc Surg. 2003;37:149–155
- . The effect of implementation of an optimized care protocol on the outcome of arteriovenous hemodialysis access surgery. J Vasc Surg. 2008;48:659–668
- . Treatment for peripheral arterial obstructive disease: An appraisal of the economic outcome of complications. J Vasc Surg. 2008;48:368–376
- . A prospective study of incidence of saphenous nerve injury after total great saphenous vein stripping. Dermatol Surg. 2008;34:1333–1339
- . Contemporary series of morbidity and mortality after lower limb amputation. Eur J Vasc Endovasc Surg. 2005;29:633–637
- . The incidence of unplanned returns to the operating room after peripheral arterial bypass surgery and its value as indicator of quality of care. Vasc Endovascular Surg. 2008;42:19–24
- . Wound complications at the groin after peripheral arterial surgery sparing the lymphatic tissue: a double-blind randomized clinical trial. Am J Surg. 2009;197:747–751
- . Nosocomial infections after peripheral arterial bypass surgery. World J Surg. 2007;31:1687–1692
- . The value of a mortality-scoring system in the quality control of patients undergoing abdominal aortic surgery. Eur J Vasc Endovasc Surg. 1999;18:523–526
- . Surgery groups differed in adverse outcome probabilities and can be used to adjust hospital comparisons. J Clin Epidemiol. 2005;58:56–62
- . Adverse outcomes in surgical patients: Implementation of a nationwide reporting system. Qual Saf Health Care. 2006;15:320–324
- . Adverse outcomes after discharge: Occurrence, treatment and determinants. Qual Saf Health Care. 2008;17:47–52
- . Management of peripheral arterial disease (PAD) (TASC working group. Transatlantic Inter-Society Consensus (TASC)). J Vasc Surg. 2000;31:S1–S296
- ACC/AHA guidelines for the management of patients with peripheral arterial disease (lower extremity, renal, mesenteric, and abdominal aortic): A collaborative report from the American Associations for Vascular Surgery/Society for Vascular Surgery, Society for Cardiovascular Angiography and Interventions, Society for Vascular Medicine and Biology, Society of Interventional Radiology, and the ACC/AGA task force on practice guidelines (writing committee to develop guidelines for the management of patients with peripheral arterial disease)—summary of recommendations. J Vasc Interv Radiol. 2006;17:1383–1397quiz 1398
- . Use of American Society of Anesthesiologists physical status classification to assess perioperative risk in patients undergoing radical nephrectomy for renal cell carcinoma. Urology. 2004;63:841–846discussion 846-7
- . Automated registration of adverse events in surgical patients in the Netherlands: the current status. Ned Tijdschr Geneeskd. 2003;147:1273–1277
- . Patient- and procedure-specific risk factors for postoperative complications in peripheral vascular surgery. Qual Saf Health Care. 2009;18:131–136
- Limb salvage after successful pedal bypass grafting is associated with improved long-term survival. J Vasc Surg. 2001;33:6–16
- Infrapopliteal-lower extremity revascularization with prosthetic conduit: a 20-year experience. Vasc Endovascular Surg. 2002;36:255–262
- Determinants of functional outcome after revascularization for critical limb ischemia: An analysis of 1000 consecutive vascular interventions. J Vasc Surg. 2006;44:747–755discussion 755-6
- The impact of diabetes on current revascularisation practice and clinical outcome in patients with critical lower limb ischaemia. Eur J Vasc Endovasc Surg. 2006;32:51–59
- A prospective analysis of critical limb ischemia: factors leading to major primary amputation versus revascularization. Ann Vasc Surg. 2007;21:458–463
- . Risk factors, medical therapies and perioperative events in limb salvage surgery: Observations from the prevent iii multicenter trial. J Vasc Surg. 2005;42:456–464discussion 464-5
- . Mortality risk reduction associated with smoking cessation in patients with coronary heart disease: a systematic review. JAMA. 2003;290:86–97
- . The role of tobacco cessation, antiplatelet and lipid-lowering therapies in the treatment of peripheral arterial disease. Vasc Med. 1997;2:243–251
- . Reoperative lower extremity revascularization with cadaver vein for limb salvage. Ann Vasc Surg. 2009;23:24–31
- Free-floating thrombus of the carotid artery: Literature review and case reports. J Vasc Surg. 2007;45:199–205
- . Factors associated with stroke or death after carotid endarterectomy in northern new england. J Vasc Surg. 2008;48:1139–1145
Competition of interest: none.
The editors and reviewers of this article have no relevant financial relationships to disclose per the JVS policy that requires reviewers to decline review of any manuscript for which they may have a competition of interest.
PII: S0741-5214(09)02058-8
doi:10.1016/j.jvs.2009.09.055
© 2010 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.
