Autogenous composite vein bypass graft for infrainguinal arterial reconstruction☆☆☆★
Article Outline
Abstract
Purpose: Lower extremity arterial reconstruction in the absence of adequate greater saphenous vein remains a challenging problem in contemporary vascular practice. The purpose of this review is to evaluate the long-term results of autogenous composite vein grafts used for infrainguinal arterial bypass grafting. Methods: We retrospectively evaluated a prospective vascular registry and reviewed inpatient and office records. Results: From June 1983 to September 1999, 165 autogenous composite vein infrainguinal bypass grafts were performed in 154 patients (87 men, 67 women; mean age, 69 years). The mean follow-up was 25 months (range, 3-147). Patients had the usual risk factors, including a 30% incidence of prior coronary bypass grafting. Forty-eight percent of bypass grafts were performed after failed previous reconstructions, and 90% were performed for limb salvage. The conduits were comprised of 2 segments (75%), 3 segments (23%), and 4 segments (2%). The distal anastomosis was at the popliteal level in 17% and the tibial/pedal level in 83%. The 30-day operative mortality rate was 1.8%. Perioperative graft failure (< 30 days) occurred in 18 bypass grafts (11%), resulting in early amputation (< 30 days) in 1.2%. The overall 5-year cumulative patency rates were 44% ± 5% for primary patency, 63% ± 5% for primary-assisted patency (PAP), and 65% ± 5% for secondary patency (SP). A high revision rate for stenosis or thrombosis was required during follow-up to maintain patency of the grafts (27%). Limb salvage was 81% ± 5% at 5 years. Primary reconstructions with composite vein fared significantly better than secondary reconstructions (SP 76% vs 54% at 5 years, P < .01). Arm vein composites showed superior patency compared with greater saphenous vein composites (SP 79% vs 61% at 5 years, P < .05). Conclusions: Infrainguinal reconstruction with autogenous composite vein results in durable graft patency and limb salvage rates in patients with few alternatives for revascularization. Intensive graft surveillance with aggressive graft revision is necessary to achieve these results. (J Vasc Surg 2001;33:259-65.)
Infrainguinal arterial reconstruction for limb salvage in the absence of adequate greater saphenous vein (GSV) remains a challenging problem in contemporary vascular practice. The high incidence of coronary artery bypass grafting and reoperative lower extremity bypass surgery has resulted in the lack of usable GSV becoming an increasingly common clinical scenario. Since the early 1980s, our strong preference has been to complete all infrainguinal reconstructions with autogenous vein, and we have been encouraged by the excellent long-term patency of these grafts.1, 2 Unfortunately, many patients lack a single segment of vein of sufficient length to complete the reconstruction. In an analysis of lower extremity revascularizations in our institution over the past 20 years, the need for ectopic/composite vein usage has increased from 5% (before 1987) to the present 19% of our lower extremity bypass procedures. In this article, we report our 16-year experience with the use of autogenous composite vein bypass grafts for infrainguinal arterial reconstruction.
Methods
A retrospective evaluation was performed on all infrainguinal bypasses using composite vein grafts done at the Brigham and Women's Hospital between June 1983 and September 1999. Only grafts that consisted of all autogenous venous segments were considered. Data were retrieved from a computerized registry in which demographics, risk factors, procedure variables, and follow-up information have been prospectively entered for all vascular surgery patients at our institution since 1975. In addition, detailed review of computerized in-patient records, office charts, operative reports, vascular laboratory reports and angiographic findings was performed. Over the last 12 years, increasing reliance has been placed on duplex scanning for preoperative mapping of ectopic veins and for postoperative graft surveillance.
The techniques of vein harvest and preparation and performance of the venovenostomy have been previously described.3 In general, a two-team approach was adopted for exposure of the inflow and outflow sites and for harvesting the ectopic vein segments. Our strategy for the prioritization of vein usage was predicated on the principle of using the best vein available for the clinical problem at hand. In these complex cases, duplex vein-mapping guided the order in which these alternative veins were used. Apart from obvious thrombosis, wall-thickening and noncompressibility, the most useful information was whether the vein was present. If a minimum diameter of 2 to 3 mm was seen in an otherwise normal vein on duplex scan, it was explored. Our intraoperative criteria for an optimal vein were a minimum diameter of 3.5 to 4 mm, easy distensibility with gentle inflation and absence of sclerotic areas. Vein segments that did not meet these criteria were excised or repaired (“upgraded”). Intraoperative angioscopy was not used in these cases.
The various vein segments were left in situ until arterial exposure was complete to minimize ischemic injury to the conduit. This also facilitated accurate determination of the length of conduit necessary to complete the bypass. The vein segments were oriented such that the largest caliber was placed proximally, creating a gradual taper of the composite graft to optimize the size match between the graft and the native vessel at the anastomoses. Valve-lysis, when required, was performed ex vivo with the retrograde modified Mills valvulotome with the vein under constant irrigation with a heparin/papaverine solution. This was completed before the venovenostomy was performed. The anastomosis was constructed by spatulating the ends of each vein, securing the heel and toe with 7-0 polypropylene suture, and running toward the middle, taking care not to purse-string the anastomosis. Completion arteriography was routinely performed in all cases to visualize the venovenostomy and the distal anastomosis. Recently, we have also used intraoperative duplex imaging to identify occult problems in the conduit.
The vein segments that have been utilized included GSV remnants, lesser saphenous vein (LSV), basilic vein (BV), and cephalic vein (CV) from all available extremities. The BV was almost always used in a nonreversed orientation because of its usual tapered anatomy. Because the length of conduit was the limiting factor in these cases, we strived to use the most acceptable distal inflow and proximal outflow sites possible. Apart from aspirin, postoperative anticoagulation was used selectively in a minority of cases.
Follow-up examinations occurred within the first month of surgery, then at 3 monthly intervals for the first year, and semiannually thereafter. Since 1988, duplex scanning has been added to noninvasive hemodynamic studies (ankle-brachial index) for detection of occult graft lesions. A return of symptoms, change in physical examination, focal increase in graft velocity (ratio > 3:1), and decreased overall graft velocity (< 45 cm/s) in a normal caliber graft were considered evidence of significant lesions and usually lead to arteriography.4
Minor amputations were defined as those resulting in a foot that could still be used for ambulation. Limb salvage was correspondingly defined as freedom from major amputation. Primary patency (PP), primary-assisted patency (PAP), and secondary patency (SP) rates were defined in accordance with the suggested reporting standards of the Ad Hoc Committee of the Society for Vascular Surgery and the North American Chapter of the International Society for Cardiovascular Surgery.5 Survival, graft patency, and limb salvage rates were calculated with the life-table method. SEs were calculated with the Greenwood method, and comparisons were made between groups with the Mantel-Cox log-rank analysis. Categoric variables were compared with χ2 analysis. A P value of less than .05 was considered to represent statistical significance. Loss to follow-up was defined as the last patient visit or contact being more than 18 months.
Results
Over the 16-year period, 165 autogenous composite vein infrainguinal bypass grafts were performed in 154 patients. There were 87 men and 67 women, with a mean age of 69 years (range, 35-88). Risk factors included diabetes mellitus (54%), hypertension (62%), cigarette smoking (42%), and coronary artery disease (69%) with 30% of patients having undergone prior coronary artery bypass grafting. Four percent of patients had dialysis-dependent renal failure. Ninety percent of the operations were performed for limb salvage (rest pain, 36%; ulcer, 33%; gangrene, 21%); the rest were for severe claudication. Forty-eight percent of bypass grafts were performed after failed previous reconstructions.
Reasons for using composite vein included lack of a sufficient single segment vein conduit in 69%, excision of a poor quality vein segment (vein upgrade) in 21%, and unknown in 10%. The conduits were comprised of 2 segments (75%), 3 segments (23%), or 4 segments (2%). Sixty-five (39%) were solely GSV composites, 36 (22%) were arm vein (AV) composites, and 64 (39%) were various arm-leg vein combinations. The proximal anastomosis arose from the common femoral artery in 68%, the proximal superficial femoral artery in 12%, the distal superficial femoral artery in 8%, the profunda femoris artery in 6%, and the popliteal artery in 6%. The distal anastomosis was located at the above-knee popliteal artery in 2%, below-knee popliteal artery in 15%, tibioperoneal trunk in 3%, anterior tibial artery in 25%, posterior tibial artery in 19%, peroneal artery in 26%, and dorsalis pedis artery in 10%.
The overall postoperative morbidity rate was 29%, including cardiac (9%) (myocardial infarction, congestive cardiac failure, arrhythmia), wound infection (3.6%), and hematoma/seroma (5.4%). Major morbidity (myocardial infarction, stroke, renal and pulmonary failure) occurred in 7%. Perioperative graft failure (< 30 days) occurred in 18 bypass grafts (11%), resulting in early amputation (< 30 days) in 1.2%. Thirty-day operative mortality occurred in three patients (1.8%) from myocardial infarction and stroke. The mean follow-up was 25 months (range, 3-147). Thirteen percent of patients were lost to follow-up.
The overall 5-year cumulative PP rate was 44% ± 5%, the PAP rate was 63% ± 5%, and the SP rate was 65% ± 5%. Overall limb salvage in patients with limb-threatening ischemia was 81% ± 5% at 5 years (Fig 1 and Appendix A).
Fig. 1.
Overall patency and limb salvage of composite vein bypass grafts.
Fig. 2.
Secondary patency of primary versus secondary bypass grafts.
Furthermore, AV composites showed superior PP and SP compared with GSV composites (61% ± 9% vs 37% ± 7%, P < .02, and 79% ± 8% vs 61% ± 8%, P < .05, respectively) (Fig 3 and Appendix C).
Fig. 3.
Patency rates of AV versus GSV composites. AV, Arm vein; GSV, greater saphenous vein.
Fig. 4.
SP of two-segment versus more than two-segment composites.
During follow-up, significant stenotic lesions were identified with duplex scanning or arteriography in 32 grafts (20%). The sites of the lesions were distributed as follows: distal anastomosis (32%), venovenostomy (30%), proximal anastomosis (22%), and midgraft residual valve cusp (16%). This information was not available in four grafts. Among the stenotic grafts, 47% had 1 lesion, 31% had 2 lesions, and 9% had more than 2 lesions. In 13% of grafts, the number of lesions could not be determined. The overall graft revision rate (for stenosis or thrombosis) for the entire series was 27%. The revision rate for GSV composites was 29%, for AV composites, 17%, and for arm-leg vein composites, 30%.
Discussion
Single-segment GSV remains the conduit of choice for infrainguinal arterial reconstruction with 5-year cumulative PP rates of 70%, SP rates of 80%, and limb salvage rates of 90%.6 When GSV is either unusable or unavailable, limb salvage becomes a more difficult challenge. There is little doubt that autogenous conduits are superior to prosthetic grafts in the infrapopliteal location.7 However, the extent to which ectopic vein segments are used to form a long composite vein graft is highly variable primarily because the procedure requires familiarity with sources of ectopic vein and the prolonged operation often required. Of greater influence in the choice of alternative conduits is a common perception among many vascular surgeons that one or more venovenostomies tend to diminish durability. This notion has not been supported by the literature, but there are few large series of autogenous composite vein grafts reported that define long-term performance.
Our institutional preference has been to exhaust all usable autogenous vein sources for limb salvage. In this series of 165 composite grafts, the overall 5-year PAP and SP rates were 63% and 65%, respectively. Limb salvage in this challenging patient population was 79% at 5 years. This was achieved despite a higher number of adverse factors, including a 48% incidence of failed previous bypass grafts and an 83% incidence of distal anastomosis at the tibial/pedal level. In the patients who underwent primary bypasses, the 5-year PAP rate of 75% approached that of single-segment GSV conduits. Although the total morbidity rate of this approach may seem high at 29%, most of it was due to early graft failure (11%), which is expected for these challenging situations. Wound complications (infection, hematoma, seroma) comprised another 9%. Major morbidity (myocardial infarction, stroke, renal and respiratory failure) occurred in only 7%, thus justifying our aggressive approach.
A somewhat remarkable finding is the superior patency of AV composites compared with GSV composites. There was no significant difference in the risk factor profiles of each group that may have contributed to this observation. The 5-year patency rate of our AV composites (PP, 61%; SP, 79%) is similar or better than those reported in the literature.8, 9, 10, 11, 12, 13 Unlike AV composite grafts, which are always performed because of the shorter length of the veins, most GSV composites were upgrades in which a suboptimal segment of the vein was excised (45 upgraded grafts vs 20 remnant GSV grafts). This may explain the poorer performance of the GSV composites because the upgraded graft may remain inherently a poor-quality conduit.
The common perception that venovenostomy adversely affects the performance of composite grafts should be addressed. We found no difference in 5-year patency rates whether one or more venovenostomies were performed. Two other studies have shown that patency rates are not influenced by the number of segments.12, 14 Composite grafts, however, are more susceptible to stenotic lesions than single-segment conduits. After an intensive graft surveillance protocol, we detected significant stenotic lesions in 20% of grafts. The overall graft revision rate was high (27%) compared with our experience with single-segment grafts (6%-7%).15 As such, PP rates will be lower, but the more relevant and important PAP and SP rates are encouraging. The distal anastomosis and the venovenostomy were the most commonly affected areas, and multiple lesions were present in at least 40% of grafts. Duplex scanning can detect these lesions that may be asymptomatic and often easily rectified. Preservation of graft function in this group of patients is crucial because the composite graft is usually the last durable option for limb salvage.
In conclusion, infrainguinal arterial reconstruction with autogenous composite vein results in durable graft patency and limb salvage rates in patients with no other realistic alternatives for revascularization. The high incidence of vein graft stenosis mandates an aggressive surveillance protocol and graft revision to achieve these excellent results. The need for multiple vein segments should not discourage its use in limb salvage situations.
Acknowledgements
We are grateful to Ms Julie Lombara for her assistance in data management.
Appendices
Appendix A:
Life table of overall composite vein grafts
Appendix B:
Life table of primary and secondary composite grafts
Appendix C:
Life table of arm vein and greater saphenous vein composite grafts
Appendix D:
Life table of two-segment and > two-segment composite grafts
Discussion
Dr George Andros (Encino, Calif). First of all, David, thank you for sending me that manuscript in a timely fashion.
The problem with the all-autogenous approach is simply a matter of supply and demand; many more patients need bypass operations than there are available saphenous veins. With the inclusion of arm veins, the supply is still insufficient, especially because of the growing number of very long grafts extending to distal targets. Thus, in an all-autogenous cosmos, the all-autogenous composite graft is both natural and inevitable. Today, we have before us the long-term results of this composite bypass strategy from a leading group, some might say the leading group, to pioneer the all-autogenous revascularization of the leg.
The authors present the outcomes of 165 grafts in 154 patients with a 16-year follow-up. These numbers suggest that the average clinical vascular fellow will have experience with about 10 to 12 composite procedures, certainly an adequate number for indoctrination into the technique. What percent of your total infrainguinal bypasses employ the autogenous composite strategy? With this practical bit of information, we can all approximate how frequently we may be called on to use vein splicing techniques ourselves.
Using a systematic graft surveillance program, the authors obtained an assisted primary patency rate of 63% and a limb salvage rate of 81% at 5 years. They also observed that secondary stenotic lesions were not unusually common at the site of venovenostomy. This, as David pointed out, is contrary to what most surgeons had feared, notwithstanding composite grafts that require revision three to four times more often than single length conduits. How do you explain this increased revision rate if the appearance of secondary stenotic lesions at the venovenostomies is relatively minor? The roughly equivalent patencies you obtained with conduits having one, two, and three venovenostomies attest to your technical skill and your ability to clinically select usable segments. Overall it's a worthy achievement.
But, there are some problems.
First, there's the surprising longevity of your patient population operated on for those most compelling indications, rest pain and ischemic necrosis. How do you account for a 5-year mortality of only 29%? Most surgical series of claudicants and limb salvage patients report a 5-year mortality of at least 50%, irrespective of whether the operation was a first-time or redo procedure. Moreover, mortality rates three times greater than those presented here have been observed in patients who had nothing more than an SFA PTA, or perhaps no intervention at all.
In fairness, other surgeons have reported unusually good mortality rates after multiple reoperations, most often with arm veins. Do your operations confer extended survival to your patient cohort, or does the multiple revascularization procedure somehow select a more long-lived subset? How does the group's mortality compare with the overall group of infrainguinal procedures that you do? This critical statistic leads one to wonder if these patients and their limbs were somehow less in jeopardy and might not have needed one of these elegant but complex and demanding operations.
Equally bewildering is a limb salvage rate that exceeds the secondary patency rate by 15%. In our experience with limb salvage patients, the ultimate loss of a patent graft is tantamount to amputation. Could you comment? The near equivalence of your primary-assisted patency and secondary patency bears witness to the success of your graft surveillance protocol. Do you recommend subcutaneous tunnels to facilitate duplex scanning?
Finally, I'm inclined to agree with your observation that primary-assisted patency of first time or primary reconstructions is better than for secondary operations. I confess I have no better reason for concurring with you than we reported the same thing. This is far from a trivial point. In fact, it may be your most important observation. Your results with primary operations at 5 years were commendable at 75%, but the secondary operations were very disappointing at 36%. If you could have known that your patency would be that low at 5 years with redo operations requiring composite grafts, wouldn't it have been better to spare the patient the long operation with multiple incisions, the patient many hours of potentially disappointing labor, by simply inserting a PTFE graft with a vein cuff?
This paper is a bounty of useful information. I recommend it to you, and I thank the Society for the opportunity of commenting. Thank you.
Dr David K. W. Chew. Thank you, Dr Andros. I hope I can remember all your questions.
First, I would say that composite vein grafts are done about 19% to 20% of the time at our institution. Probably because of the referral patterns, we get a lot of patients who have had previous bypasses elsewhere, and we are aggressive at limb salvage. It always seems that every time we present a series, we get asked the same question of why our patients live so long. And I have to suspect that it's probably better screening. We have a good cardiology team, a vascular medicine cardiology team, that works closely with us to see who would and who would not tolerate a revascularization procedure in the extremity. Although, for our secondary bypass group the patency rates were not as good as the primary bypasses, I think it's hard to predict who would do well and who would not. And our current preference is still that if there is a distal target vessel and the patient has usable vein, we have been able to two-team these operations and get them done within 3 hours. So I don't think it really is as long as what most people would think it is if you adopt a two-team approach.
The venovenostomy was originally thought to be the most problematic site, but, as shown in this study, I think that the venovenostomy is just another potential site of a problem. It is an anastomosis that is just as problematic as the proximal or the distal anastomosis. Finally, I think that primary patency in these grafts mean nothing. With aggressive graft surveillance, we can salvage these grafts and fix them before they go down. We feel that this is the most durable option for limb salvage in this challenging patient population.
Dr Frank T. Padberg, Jr (Newark, NJ). The worst thing in vascular reconstruction of the lower extremity is bad vein. I'd like to ask how you defined acceptable or “good” vein? You said you used vein mapping, and you probably expressed it in your manuscript, but not in the presentation. What were your criteria for acceptable vein?
Likewise, we have extended ourselves beyond the use of greater saphenous, lesser saphenous, and arm vein, into occasionally using branches of the saphenous. My second specific question was whether or not you have used saphenous branch veins and whether or not they had any impact on your results?
And thirdly, although I'm sure you defined it in the manuscript but not in the presentation, I question the term composite vein. Oftentimes in our usage we use that to refer to a prosthetic plus a piece of vein, rather than two pieces of vein, which would be all autogenous. So perhaps autogenous composite would be more acceptable. Could you please comment?
Dr Chew. Well, I think our experience is that duplex scanning shows us whether the vein is present or not. Oftentimes, you really can't be sure until you take the vein out and see it in the distended state. We like to see a vein that's without any sclerotic areas, that distends evenly, and with a minimum diameter of 3.5 to 4 mm. Our vein mapping is done with the extremities in the dependent position, but I think the most useful information is whether the vein is there or isn't there. If it warrants exploration, we would explore the vein and take it out and see whether it will distend.
With regard to your second question, was it the use of lesser saphenous vein?
Dr Padberg. Branches of saphenous vein rather that greater saphenous or lesser saphenous channels specifically.
Dr Chew. If there is a good branch of the greater saphenous vein, we'll use it, because I think it works equally well in the patients with duplicated systems. And if you're lucky, you get two nice big duplicated channels, which increases your options.
Dr Padberg. Did those work as well as the others, or did you have a chance to look at that?
Dr Chew. In the 165 grafts, I remember seeing a small number where we encountered branches and we used them. Now, I don't have the data on the follow-up of these branches.
With regard to composite vein, I know that in the literature it's quite confusing, but we refer to all-autogenous composite vein grafts.
Dr Gregory L. Moneta (Portland, Ore). I was just wondering, last year we suggested that if you're going to revise vein grafts that we ought to do an angiogram before each one because sometimes we find lesions that were not found on the original duplex study. And you said you found multiple lesions in about 20% of your grafts that you revised. How many of those did you find with your initial duplex surveillance, where you found all the lesions, versus how often did the angiogram really find a lesion that was missed on the duplex?
Dr Chew. Well, I think most of our vein graft revisions had an angiogram before revision, but I don't have the data on what percentage was missed on duplex scanning.
References
- . Short-term and midterm results of an all-autogenous tissue policy for infrainguinal reconstruction. J Vasc Surg. 1989;9:107–114
- . Further experience with an all-autogenous tissue policy for infrainguinal reconstruction. J Vasc Surg. 1993;18:41–48
- . Composite autogenous vein grafts. Semin Vasc Surg. 1995;8:202–208
- . The origin of infrainguinal vein graft stenosis: a prospective study based on duplex surveillance. J Vasc Surg. 1995;21:16–25
- Recommended standards for reports dealing with lower extremity ischemia: revised version. J Vasc Surg. 1997;26:517–538
- . Infrainguinal bypass. In: 5th ed. Rutherford RB editors. Vascular surgery. Philadelphia: : WB Saunders; 2000;p. 1012; Table 69-1
- Six-year prospective multicenter randomized comparison of autologous saphenous vein and expanded polytetrafluoroethylene grafts in infrainguinal arterial reconstructions. J Vasc Surg. 1986;3:104–114
- . Arm veins for arterial revascularization of the leg: arteriographic and clinical observations. J Vasc Surg. 1986;4:416–427
- Results of a policy with arm veins used as the first alternative to an unavailable ipsilateral greater saphenous vein for infrainguinal bypass. J Vasc Surg. 1996;23:130–140
- . The use of arm vein conduits during infrageniculate arterial bypass. J Vasc Surg. 1992;16:420–427
- . Cephalic vein grafts for lower extremity revascularization. J Vasc Surg. 1992;15:543–549
- The use of arm vein in lower-extremity revascularization: results of 520 procedures performed in eight years. J Vasc Surg. 2000;31:50–59
- . Successful long term limb salvage using cephalic vein bypass grafts. Ann Surg. 1984;200:785–791
- . The use of spliced vein bypasses for infrainguinal arterial reconstruction. J Vasc Surg. 1995;21:403–412
- . Infrainguinal arterial reconstruction with nonreversed greater saphenous vein. J Vasc Surg. 1996;24:957–962
☆ Competition of interest: nil.
☆☆ Reprint requests: Michael Belkin, MD, Division of Vascular Surgery, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115 (e-mail: mbelkin@partners.org ).
★ For
Appendices A through D,
PII: S0741-5214(01)49106-3
doi:10.1067/mva.2001.112699
© 2001 Society for Vascular Surgery and The American Association for Vascular Surgery. Published by Elsevier Inc. All rights reserved.
