Umbilical Vein Grafts Research Articles

Evaluation Of The Artegraft Conduit For Lower Extremity Revascularization: Retrospective Analysis Of Outcomes When Used In The Situation Of No Available Autologous Saphenous Vein For Conduit In Lower Extremity Bypass Procedures

Artegraft is a biological conduit made from bovine carotid artery. Over the years, there have been a multitude of studies evaluating the outcomes of Artegraft in arteriovenous access for hemodialysis. There are limited reports on its use in lower extremity revascularization. Use of other biologic grafts such as the umbilical vein graft showed superior outcome compared with other non-biologic grafts in lower extremity bypass. The objective of this paper was to evaluate our experience utilizing Artegraft in lower extremity bypasses when no native venous conduit was available.

A Feasible Technique for Middle Hepatic Vein Reconstruction in Right Lobe Liver Transplantation: Usage of Autologous Portal Vein With Bench Recanalized Umbilical Vein Graft.

Background Middle hepatic vein (MHV) reconstruction is necessary to achieve a good outcome in right lobe liver transplantation. Many successful reconstruction methods have been reported as there are anatomical variations in MHV tributaries. Some methods are time consuming to perform routinely and other methods are not applicable in all anatomical variations. Large series which describe routine use of portal vein (PV) and bench recanalized umbilical vein (UV) graft have not been reported. In this paper, we report our experience of this novel technique of MHV reconstruction as a standard protocol. Material and method From February 2017 to December 2018, there were 301 patients who received right lobe liver transplant in our Centre, and the new MHV in 268 grafts were reconstructed with autologous PV and bench recanalized UV. The length of the vein graft and distance between segment 5 branch and MHV orifice were measured. We divided these patients into 3 risk groups according to the MHV drainage area (congestion volume) of the right lobe (Low risk: under 30%, Medium risk: 31 to 45%, High risk: over 45%). Clinical data was collected, and perioperative data were compared between the 3 groups. Results The distance from V5 to MHV orifice, PV autologous graft only, and PV&UV was 9.5±2.5, 7.2±1.5, 13.5±2.2 cm respectively. The patency rate of our reconstructed MHV was 97% and 89% at 1 month and 1 year respectively. There was no significant difference in perioperative data among the 3 groups. The survival in medium and high groups were statistically equivalent to that in low risk group. Conclusion Autologous portal with bench recanalized umbilical vein graft shows a high patency rate and achieves satisfactory outcome in grafts with large MHV drainage area. This graft is able to deal with all the MHV tributary variations by a single method.

Sphingosine-1-phosphate improves endothelialization with reduction of thrombosis in recellularized human umbilical vein graft by inhibiting syndecan-1 shedding in vitro.

Sphingosine-1phosphate (S1P) is a low molecular-weight phospholipid mediator that regulates diverse biological activities of endothelial cell, including survival, proliferation, cell barrier integrity, and also influences the development of the vascular system. Based on these characters, we the first time to use it as an additive during the process of a small caliber blood vessel construction by decellularized human umbilical vein and endothelial cell/endothelial progenitor. We further explored the function and mechanism of S1P in promoting revascularization and protection against thrombosis in this tissue engineered vascular grafts. The results showed that S1P could not only accelerate the generation but also reduce thrombus formation of small caliber blood vessel.

Living Donor Liver Transplantation Using a Right Liver Graft With Additional Vein Reconstructions for Patient With Situs Inversus

Living donor liver transplantation (LDLT) using a right liver graft with additional vein reconstructions has not been previously reported in a situs inversus (SI) patient. A 60-year-old man with SI was referred for LDLT for end-stage cirrhosis secondary to hepatitis B. The calculated regional volumes of the individual hepatic vein territories in the right liver graft suggested that the middle hepatic vein (MHV) tributaries and the inferior right hepatic veins (IRHVs) should be reconstructed in addition to the right hepatic vein (RHV). On the back-table, the recipient's recanalized umbilical vein graft was anastomosed to the V5 opening, and the other side of vein graft was anastomosed to the RHV and V8 opening to create a large single orifice. After total hepatectomy, the right liver graft was placed in the left subphrenic space at the reversed position. The common orifice of hepatic venous drainage from RHV, V8 and V5 was anastomosed to the anatomical RHV conduit of the recipient, followed by IRHV anastomosis to the inferior vena cava. Postoperative course was almost uneventful, and no vascular complications were experienced. Even for SI patients, LDLT using a right liver graft with reconstructions of the MHV tributaries and the IRHVs is feasible.

The Utility of Recanalized Umbilical Vein Graft to the Hepato-pancreato-biliary Surgeon

The authors recently published their experience of recanalizing umbilical veins in deceased liver donors, with recanalized umbilical veins as vascular conduits for meso-Rex bypass procedures. They have since found recanalized umbilical veins to be an excellent, easy to harvest vascular conduit that can be used for multiple vascular procedures and repair. Here, they report their experience using this vessel for bypass and vascular reconstruction. They have recanalized umbilical veins and used them in a total of 5 Meso-Rex bypasses; 5 pancreaticoduodenectomies; 1 left hepatic trisegmentectomy with right portal vein (PV) resection and reconstruction; 1 right hepatectomy and 1 adrenalectomy, both with partial inferior vena cava (IVC) resection and reconstruction; 1 coronary-Rex bypass shunt for extrahepatic PV thrombosis; and 1 orthotopic liver transplantation with infrahepatic IVC anastomotic dehiscence patched with umbilical vein graft. Umbilical veins were dilated mechanically and used in situ for the meso-Rex bypass surgery; they were ligated in the space of Rex and then dilated ex vivo otherwise to be used as interposition grafts or a vein patch. A total of 15 hepato-pancreato-biliary procedures were done using the recanalized umbilical vein as graft; 2 patients required thrombectomy postoperatively with reexploration, venotomy, thrombectomy with fogarty catheter, and venotomy closure. The umbilical vein graft is a fine vascular conduit and can serve many purposes in hepatobiliary surgery.

All-in-one sleeve patch graft venoplasty for multiple hepatic vein reconstruction in living donor liver transplantation

ObjectivesThis paper presents an innovative technique to address complex multiple hepatic vein (HV) reconstruction in right lobe graft living donor liver transplantation (RL-LDLT). MethodsA patient with hepatitis C virus-related cirrhosis underwent RL-LDLT. The graft had seven HVs, including: the right HV (17mm); one segment VII HV (11mm); two segment VI HVs (6mm and 16mm), and three segment V HVs. The graft weighed 663g (53% of standard liver volume; ratio of graft weight to recipient body weight: 0.96). Each HV had significant drainage territory requiring reconstruction. A cryopreserved iliac vein graft was used to create a sleeve patch to incorporate the HV openings. The holes were anastomosed to their corresponding HV tributaries using continuous 6–0 polydioxanone (PDS) sutures. Two of the three segment V HVs were combined using a smaller iliac vein patch, which was anastomosed in an end-to-side fashion to a previously harvested recipient umbilical vein interposition graft. The other end of the umbilical vein graft was anastomosed to the larger iliac vein sleeve patch. ResultsOverall, six HV openings were incorporated in one sleeve patch to allow a single wide anastomosis with the recipient inferior vena cava. Doppler ultrasound after reconstruction showed adequate flow patterns in all the HVs. ConclusionsAll-in-one sleeve patch graft venoplasty simplifies the reconstruction of multiple HVs and reduces warm ischaemia time in RL-LDLT with excellent outcomes.

Biological grafts as arterial substitute in the infragenicular level: A prospective evaluation

In order to evaluate patency and clinical success rates, foot salvage rates, and complications associated with the use of two biological graft conduit materials, the authors performed a prospective study of 109 femoroinfrageniculate bypasses performed over six years. The two grafts studied as arterial substitutes were chemically processed human umbilical vein (HUV) graft and ovine collagen graft (OCG). Indications for surgery were disabling claudications (11%), acute ischemia (20%), rest pain (35%), and nonhealing ulceration or gangrene (34%). Sixty-two (57%) operations were repeat procedures for occluded grafts. Major complications occurred in 11.9%: 4 deaths, 1 acute renal failure, 4 graft infections, 4 anastomotic hemorrhages, and 1 case of inadequate graft rinsing. There were 39 early occlusions, which resulted in one-month primary patency rates of 59% (OCG) and 69% (HUV) and secondary patency rates of 71% (OCG) and 87% (HUV). The primary and secondary patency rates at two years were 47% and 58% for OCGs, 42% and 58% for HUVs. The mean foot salvage rates at one month were 82.5% (OCG) and 95.3% (HUV) and at one year were 73% (OCG) and 82% (HUV). These results did not show statistically relevant differences between the two graft materials (chi square = 0.891,p>0.1). Acute ischemia was associated with a higher percentage of failure when compared with chronic ischemia, but significance was not reached (chi square = 2.77,p=0.10). However, patients with repeat procedures were associated with higher rates of failure than those undergoing primary procedures (chi square = 5.12,p=0.025).

Femoropopliteal prosthetic bypass with glutaraldehyde stabilized human umbilical vein (HUV)

Femoropopliteal bypass still is the standard surgical therapy for disabling claudication and critical ischemia. When autologous vein is not suitable synthetic or biological prostheses may be considered. Second generation glutaraldehyde tanned human umbilical vein (HUV) graft was chosen for above and below knee femoropopliteal bypass when autologous vein was not available. A single center experience regarding long-term graft function, secondary reinterventions, and potential biodegeneration of the HUV is presented. Between January 1994 and January 2005, 211 consecutive femoropopliteal bypass operations with HUV (65 above knee and 146 below knee) were performed in 197 patients for disabling claudication (57), chronic critical ischemia (130), popliteal artery aneurysm (9), acute ischemia (14), or aneurysmal degeneration of a synthetic graft (1) in the absence of suitable ipsilateral great saphenous vein. Grafts were followed with duplex scan supplemented by additional angiography in case of recurrent ischemia with prospective documentation of follow-up data in a computerized vascular database. Surveillance of the HUV included routine evaluation of potential biodegeneration with duplex scan. Retrospective analysis of graft patency, limb salvage, and signs of aneurysmal degeneration was performed. Mean (median) follow-up was 44 (35) months (range 1 to 143 months). Thirty-day mortality was 2.4%. Early postoperative bypass thrombosis after a median of 4 days postoperatively (0 to 30 days) prompted revision with thrombectomy in 16% of cases. Besides late bypass thrombosis in 14.7%, additional operative or endovascular reinterventions during follow-up to maintain or restore graft patency was necessary in 8.5% of bypasses. Primary, primary assisted, secondary patency rate, and limb salvage rate after 5 years were 54%, 63%, 76%, and 92%, respectively, for all bypasses with no significant difference between above and below knee anastomosis. Duplex scan identified segmental aneurysmal degeneration in six grafts, which led to operative reintervention in three cases. The rate of detected aneurysm for grafts patent for more than three years was 7% with a rate of reintervention for aneurysm of 3.5%. Although a considerable rate of early thrombotic occlusions occurred, excellent secondary graft patency and limb salvage combined with a tolerable rate of late aneurysmal degeneration detected by means of duplex scan surveillance justify the use of the HUV in femoropopliteal bypass surgery when ipsilateral autogenous vein is not suitable.

Novel thromboresistant materials

The development of a clinically durable small-diameter vascular graft as well as permanently implantable biosensors and artificial organ systems that interface with blood, including the artificial heart, kidney, liver, and lung, remain limited by surface-induced thrombotic responses. Recent breakthroughs in materials science, along with a growing understanding of the molecular events that underlay thrombosis, has led to the design and clinical evaluation of a variety of biologically active coatings that inhibit components of the coagulation pathway and platelet responses by surface immobilization or controlled release of bioactive agents. This report reviews recent progress in generating synthetic thromboresistant surfaces that inhibit (1) protein and cell adsorption, (2) thrombin and fibrin formation, and (3) platelet activation and aggregation.

Venous outflow reconstruction with surgically reopened obliterated umbilical vein in domino liver transplantation

Venous outflow reconstruction with surgically reopened obliterated umbilical vein in domino liver transplantation

Tissue-on-Tissue Testing of Dry Eye Formulations for Reduction of Bioadhesion

Glutaraldehyde-preserved, human umbilical cord vein graft (UCVG) was selected as a stable surrogate tissue source for testing of bioadhesion-reducing lubricants. Bioadhesion, as manifested in tissue-on-tissue friction coefficients of 0.2–0.4 for saline-lubricated UCVG, was quantitatively and persistently reduced after the instillation of a single aliquot of an ophthalmic “artificial tears” formulation containing active demulcents polyethylene glycol (PEG400) and propylene glycol (PG), as well as a gellable hydroxypropyl guar (HP Guar) in a borate-buffered solution between the “blinking” tissues. Reduced adhesion was maintained (was “substantive”), even after rinsing excess lubricant from the surfaces. Comparative tests with tissue-on-solid, and solid-on-solid, similarly lubricated couples point to a potentially unique mechanism that involves macromolecules modifying the tissue phases to provide rinse-resistant lubricity and surface protection in articulated tissue-to-tissue interfaces. Results for tissue-on-tissue couples were obtained in laboratory trials utilizing a reciprocating pin-on-disc type friction/wear test device articulating preserved human umbilical cord vein segments under increasing loads, and again after saline rinsing to determine persistence of the friction-reducing effects. A single confirmatory test using donated human cornea against vein graft tissue showed the lowest coefficient of friction, below 0.05, for the “artificial tears” formulation. Mechanistic studies employing the same test device and protocol for metal oxide (germanium)-on-metal oxide couples, as well as for metal oxide-on-tissue couples, indicated that simple increases in viscosity were not the likely sources of friction reduction, and revealed frictional values higher than measured for the similarly lubricated tissue-on-tissue couples. Thus, formulation development to minimize bioadhesion requires that appropriate simulations be used to obtain clinically predictive data for circumstances of liquid uptake into the tissues, resultant tissue swelling, and binding to impermeable adjacent materials.

Sequential Femoral Distal Composite Bypass with Second Generation Glutaraldehyde Stabilized Human Umbilical Vein (HUV)

Conclusion: Limb salvage and graft patency rates with sequential composite bypasses composed of second generation human umbilical vein grafts and autogenous vein provide reasonable primary and secondary patency rates and are associated with excellent limb salvage. Summary: The authors sought to evaluate a policy of using a combination of second generation human umbilical vein (HUV) grafts and autogenous vein as a sequential conduit in patients felt to have inadequate autogenous conduit for construction of an all autogenous lower extremity bypass. This was a retrospective study from a single center in Germany. From January 1998 to December 2003, 1,231 infrainguinal bypasses were performed in this center. Of those, 54 consisted of a femoral-distal HUV-autologous vein sequential composite bypass. All patients had critical leg ischemia and were felt to have an absence of sufficient length of autogenous vein. The sequential HUV-composite technique was reviewed for graft patency, limb salvage, and patient survival. Primary and secondary patency rates at 1, 2, 3 and 4 years were 71, 61, 53 and 53%, and 89, 80, 73 and 67% respectively. Limb salvage rates at 1, 2, 3, and 4 years were 96, 92, 88 and 88%. Four year survival was 56%. After one month, additional graft based procedures were required in six bypasses. Five patients had asymptomatic occlusion of one sequential anastomosis. There were no identified complications related to bio-degeneration of the HUV graft. Comment: There still remains some interest in the use of human umbilical vein grafts. The author’s technique of using human umbilical vein grafts as the prosthetic component of a prosthetic/autologous sequential composite bypass has provided reasonable results in terms of both patency and limb salvage. The results differ little from what one would expect with similar procedures with PTFE grafts. Bio-degeneration of the HUV grafts in this series of limb salvage patients appeared to be a non issue. If a sequential composite autogenous graft is required it appears to make little difference whether the prosthetic component is PTFE or human umbilical vein.

Infrainguinal bypass surgery: Factors determining late graft patency

The results of 373 infrainguinal bypass grafts, in a single centre, between 1980 and 1988 are reviewed. One hundred and thirty in situ vein (ISV), 47 reversed saphenous vein (RSV), 118 polytetrafluoroethylene (PTFE) and 78 human umbilical vein (HUV) grafts were used. The indications for surgery were disabling claudication in 25 per cent of patients and limb salvage in 75 per cent. In 36 per cent of operations the distal anastomosis was above the knee and in 64 per cent it was below the knee. Overall 5-year patency rates and limb salvage rates respectively were, for ISV (41 and 69 per cent), RSV (62 and 90 per cent), PTFE (31 and 67 per cent) and HUV (29 and 59 per cent). There was no significant difference in patency among these grafts at the above-knee level, but significant differences between vein and prosthetic grafts were evident below the knee (P less than 0.001). Using a proportional hazards model the three factors that consistently correlated with late graft patency were graft type (P less than 0.001), site of distal anastomosis (P less than 0.001) and distal run-off (P less than 0.001). Overall, the results suggest that prosthetic grafts are a suitable alternative to autogenous vein when the distal anastomosis is above the knee, but vein should always be used, if available, below the knee joint.

Human umbilical vein and PTFE grafts compared in an artificial circulation

Human umbilical vein and PTFE grafts compared in an artificial circulation

Biomechanical properties of different segments of human umbilical cord vein and its value for clinical application

No satisfactory effects have been obtained with the use of synthetic blood vessels (diameter <6 mm) as substitutes for human small arteries or veins for the purpose of clinical vascular reconstruction. Therefore, blood vessels of human origin, for example, umbilical cord blood vessels, with their wide availability, still should be considered. However, little information on biomechanical properties of human umbilical cord blood vessels is available. The objective was to provide a theoretical basis for the clinical application of umbilical cord veins as optional material for small-caliber grafts. This was a nonrandomized, noncontrolled in vitro study. The experiment was conducted in the Laboratory of Medical Biomechanics, Yunyang Medical College. Umbilical cord veins of 20 normal fetuses of spontaneous labor were collected by the Department of Obstetrics and Gynecology, Taihe Hospital in Shiyan City, Hubei Province. The fetuses aged 37-40 weeks, and the parturients were 20-30 years old. Umbilical cord veins of the 20 fetuses were used and the placental ends were treated as proximal ends while the fetal ends as distal ends. The fetal ends were divided into three segments: proximal, middle, and distal segments. The relationship between pressure of umbilical cord veins segments and the diameters was measured on the biomechanical experiment stand for soft tissues, and then the elastic modulus was calculated. The materials were transversely extracted, refrigerated, and sliced up before HE staining. The geometrical morphology indexes were measured by a computer image analysis system (Leica-Q500IW). The main outcome measures were: incremental elastic modulus (E(inc)), pressure-strain elastic modulus (E(p)), volume elastic modulus (E(v)), diameter, and wall thickness of the veins. E(inc), E(p), and E(v) of umbilical cord veins of proximal, middle, and distal segments increased with the pressure elevated. The three kinds of elastic modulus of proximal segments (E(inc): 26.98 +/- 3.21, E(p): 16.58 +/- 2.12, E(v): 8.31 +/- 2.35) were all lower than those of distal segments (E(inc): 33.20 +/- 4.21, E(p): 119.45 +/- 2.87, E(v): 9.71 +/- 1.32) (F = 95.74-126.52, p < 0.05), and a tendency to increase was shown from proximal segments to distal segments. Media thickness [(0.30 +/- 0.05)] mm, (0.24 +/- 0.03) mm] and the diameters [(3.07 +/- 0.12) mm, (2.30 +/- 0.13) mm] decreased gradually from proximal to distal segments (F = 12.76, p < 0.01). It is feasible to use umbilical cord veins as substitutes for the transplantation of small-caliber arteries in terms of basic biomechanical properties. On vascular grafting, different segments of umbilical cord veins should be chosen cautiously so that the biomechanical characteristics of umbilical cord vein grafts could be in accordance with those of host to increase the long-term patency rate of transplanted blood vessels.

Bile duct reconstruction with pedicled umbilical vein graft

目的 进一步总结带蒂脐静脉瓣胆道修复的临床经验和远期随访结果.方法第一种术式,胆管上下端后壁对端吻合,前壁纵行切开,其缺损以带蒂脐静脉瓣修复21例;第二种术式,胆管狭窄切开、整形,胆管缺损以带蒂脐静脉瓣修复18例.结果本组无死亡病例.术后达7年以上25例,其中再手术3例,术后7～12年ERCP 9例,双剂量静脉胆道造影1例,胆道显影均正常;轻度胆管炎2例;另10例无任何症状,B超胆道未见异常.结论带蒂脐静脉瓣胆道修复是一种理想的胆道修复手术。

Regarding “cryopreserved saphenous vein allografts in infrainguinal revascularization: analysis of 240 grafts”

Farber et al (J Vasc Surg 2003;38:15-31) have defined a specific role for the use of cryopreserved saphenous vein in infrainguinal revascularization. However, their reference to the umbilical vein is based on an article published in the Journal of Vascular Surgery in 1988. The authors should have referred to a subsequent publication,1Dardik H. Wengerter K. Qin F. Pangilinan A. Silvestri F. Wolodiger F. et al.Comparative decades of experience with glutaraldehyde-tanned human umbilical cord vein graft for lower limb revascularization an analysis of 1275 cases.J Vasc Surg. 2002; 35: 64-71Abstract Full Text Full Text PDF PubMed Scopus (97) Google Scholar which clearly showed no aneurysmal degeneration in the series followed during the decade 1990 to 2000. Their comments and conclusions with regard to the current status of the use of umbilical vein grafts would have been different and more accurate in describing the current status of this material.

Comparative decades of experience with glutaraldehyde-tanned human umbilical cord vein graft for lower limb revascularization: An analysis of 1275 cases

Purpose: Biological material has been used as an alternative to autogenous vein since the first lower extremity revascularization procedures were performed. Our experience with glutaraldehyde-tanned human umbilical cord vein graft (UVg), which spanned a period of 28 years, forms the basis of this report, with an emphasis on comparative results between the two decades from 1975 to 1985 and from 1990 to 2000. Methods: Between 1990 and 2000, 283 lower extremity bypass grafting procedures were performed in 230 patients (264 limbs), with UVg used as the predominant, or sole, graft material. Our experience with 907 reconstructions in the decade from 1975 to 1985 has been previously documented and now serves as a baseline comparison with the past decade of experience with UVg. Each reconstruction was classified on the basis of the distal anastomotic site with or without distal arteriovenous fistulas (dAVFs). The primary and secondary graft patency rates were determined for each category as was cumulative palliation, which combines the end points of graft failure, amputation, and death Results: The results from the second decade (1990 to 2000) showed a continuation of improving patency rates for UVg grafts in lower extremity revascularization. Comparison results of complications showed no changes in the low incidence rates of infection, stenosis, dissection, and pseudoaneurysm. The original series results showed a 2.9% requirement for aneurysm surgery, with an incidence rate of biodegradation of 57% (36% aneurysms, 21% dilation), whereas the current series results have shown no aneurysms to date. The comparative 6-year secondary patency rates for past and current popliteal and crural bypass grafts (with or without dAVF) were: popliteal, 53% versus 67%, P <.05; and crural, 26% without dAVF versus 47% with dAVF, P <.05. The limb salvage rates for the two series at 6 years showed no significant changes between the decades and the types of bypass grafts. Thrombolysis was performed during the decade from 1990 to 2000 in 27 UVg cases, with lysis achieved in 23 cases (85%) and limb salvage achieved in 20 cases (74%). Since 1996, associated endovascular procedures (fluoroscopy, angioplasty) have assumed increasing importance in the reduction of perioperative graft closure and in the enhancement of patency Conclusion: Our continuing experience with UVg confirms that favorable results can be obtained with this biologic alternative to autologous vein for lower limb revascularization. Concern regarding biodegradation and aneurysm formation even after 5 years are unfounded at this time. Improved patency and limb salvage rates can be achieved in concert with lower nonthrombotic failure rates, increasing performance of associated endovascular procedures, use of tourniquets, and the addition of dAVF for crural bypass grafting. Prospective randomized studies are still necessary for the assessment of the comparative role of all graft materials, a project that continues to evade our specialty. (J Vasc Surg 2002;35:64-71.)

Comparative decades of experience with glutaraldehyde-tanned human umbilical cord vein graft for lower limb revascularization: An analysis of 1275 cases*1

Comparative decades of experience with glutaraldehyde-tanned human umbilical cord vein graft for lower limb revascularization: An analysis of 1275 cases*1

A comparative evaluation of polytetrafluoroethylene, umbilical vein, and saphenous vein bypass grafts for femoral-popliteal above-knee revascularization: A prospective randomized Department of Veterans Affairs cooperative study

Purpose: Currently, the choice of a vascular prosthesis for a femoral-popliteal above-knee arterial bypass graft is left to the surgeon's preference, because the available information on comparative evaluations is inconclusive. The Department of Veterans Affairs (VA) Cooperative Study 141 was established to identify whether improved patency exists with different bypass graft materials for patients with femoral-popliteal above-knee bypass grafts. Methods: Between June 1983 and June 1988, 752 patients at 20 VA medical centers were randomized to receive either an externally supported polytetrafluoroethylene (PTFE; N = 265), human umbilical vein (HUV; N = 261), or saphenous vein (SV; N = 226) for an above-knee femoral-popliteal bypass graft. The indication for the bypass grafting operation was limb salvage in 67.5% of the patients. Patients were observed every 3 months for the first year and every 6 months thereafter. All patients were instructed to take aspirin (650 mg) daily for the duration of the study. Doppler-derived ankle-brachial indices (ABIs) were determined preoperatively and serially postoperatively. A bypass graft was considered to be patent when the Doppler-derived postoperative ABI remained significantly improved (more than 0.15 units higher than their preoperative value) and additional objective information, such as angiograms or operations, did not contradict these observations. Patency failure also included bypass grafts that were removed because of an infection or aneurysmal degeneration. Patency rates were compared by using the Kaplan-Meier life table analysis. Results: The cumulative assisted primary patency rates were statistically similar among the different conduit types at 2 years (SV, 81%; HUV, 70%; PTFE, 69%). After 5 years, above-knee SV bypass grafts had a significantly (P ≤.01) better patency rate (73%) than HUV bypass grafts (53%), which had a significantly (P ≤.01) better patency rate than PTFE bypass grafts (39%). Limb salvage was slightly worse with PTFE conduits. The number of bypass graft thromboses and major amputations within the first 30 days was highest in the HUV group. Conclusion: The overall results of this prospective randomized study suggest that the SV should be considered as the bypass graft of choice for femoral-popliteal above-knee reconstruction and that, when a prosthetic bypass graft is used, an HUV should also be considered as an alternative choice to PTFE. (J Vasc Surg 2000;32:268-77.)