Chirurgie fémoro-poplitée - Femoro popliteal bypass

1. Malmstedt J et al. (2005). "A randomized prospective study of valvulotome efficacy in in situ reconstructions." Eur J Vasc Endovasc Surg 30(1): 52-6
2. Schouten O et al. (2005). "End-to-end versus end-to-side distal anastomosis in femoropopliteal bypasses; results of a randomized multicenter trial." Eur J Vasc Endovasc Surg 29(5): 457-62
3. Panneton JM et al. (2004). "Multicenter randomized prospective trial comparing a pre-cuffed polytetrafluoroethylene graft to a vein cuffed polytetrafluoroethylene graft for infragenicular arterial bypass." Ann Vasc Surg 18(2): 199-206
4. Ballotta E et al. (2004). "Prospective randomized study on reversed saphenous vein infrapopliteal bypass to treat limb-threatening ischemia: common femoral artery versus superficial femoral or popliteal and tibial arteries as inflow." J Vasc Surg 40(4): 732-40.
5. Devine,C, C McCollum (2004). "Heparin-bonded Dacron or polytetrafluorethylene for femoropopliteal bypass: five-year results of a prospective randomized multicenter clinical trial." J Vasc Surg 40(5): 924-31
6. Griffiths GD et al. (2004). "Randomized clinical trial of distal anastomotic interposition vein cuff in infrainguinal polytetrafluoroethylene bypass grafting." Br J Surg 91(5): 560-2
7. Klinkert P et al. (2003). "Vein versus polytetrafluoroethylene in above-knee femoropopliteal bypass grafting: five-year results of a randomized controlled trial." J Vasc Surg 37(1): 149-55
8. Ballotta E, et al. (2003). "Prospective randomized study on bilateral above-knee femoropopliteal revascularization: Polytetrafluoroethylene graft versus reversed saphenous vein." J Vasc Surg 38(5): 1051-5
9. Kreienberg PB et al. (2002). "Early results of a prospective randomized trial of spliced vein versus polytetrafluoroethylene graft with a distal vein cuff for limb-threatening ischemia." J Vasc Surg 35(2): 299-306
10. Devine C et al. (2001). "Heparin-bonded Dacron or polytetrafluoroethylene for femoropopliteal bypass grafting: a multicenter trial." J Vasc Surg 33(3): 533-9
11. Post S et al. (2001). "Dacron vs. polytetrafluoroethylene grafts for femoropopliteal bypass: a prospective randomised multicentre trial." Eur J Vasc Endovasc Surg 22(3): 226-31
12. Burger DH et al. (2000). "A prospective randomized trial comparing vein with polytetrafluoroethylene in above-knee femoropopliteal bypass grafting." J Vasc Surg 32(2): 278-83
13. Johnson W, KK Lee (2000). "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." J Vasc Surg 32(2): 268-77
14. Green RM et al. (2000). "Prosthetic above-knee femoropopliteal bypass grafting: five-year results of a randomized trial." J Vasc Surg 31(3): 417-25
15. Robinson BI et al. (1999). "A prospective randomized multicentre comparison of expanded polytetrafluoroethylene and gelatin-sealed knitted Dacron grafts for femoropopliteal bypass." Cardiovasc Surg 7(2): 214-8
16. Hamsho A et al. (1999). "Prospective randomised trial of distal arteriovenous fistula as an adjunct to femoro-infrapopliteal PTFE bypass." Eur J Vasc Endovasc Surg 17(3): 197-201
17. Stonebridge PA et al. (1997). "Randomized trial comparing infrainguinal polytetrafluoroethylene bypass grafting with and without vein interposition cuff at the distal anastomosis. The Joint Vascular Research Group." J Vasc Surg 26(4): 543-50
18. Watelet J et al. (1997). "Femoropopliteal bypass: in situ or reversed vein grafts? Ten-year results of a randomized prospective study." Ann Vasc Surg 11(5): 510-9
19. Abbott WM et al. (1997). "Prosthetic above-knee femoropopliteal bypass grafting: results of a multicenter randomized prospective trial. Above-Knee Femoropopliteal Study Group." J Vasc Surg 25(1): 19-28
20. Aalders GJ, TJ van Vroonhoven (1992). "Polytetrafluoroethylene versus human umbilical vein in above-knee femoropopliteal bypass: six-year results of a randomized clinical trial." J Vasc Surg 16(6): 816-23; discussion 823-4
21. Moody AP et al. (1992). "In situ versus reversed femoropopliteal vein grafts: long-term follow-up of a prospective, randomized trial." Br J Surg 79(8): 750-2
22. McCollum C et al. (1991). "PTFE or HUV for femoro-popliteal bypass: a multi-centre trial." Eur J Vasc Surg 5(4): 435-43.
23. Wengerter KR et al. (1991). "Prospective randomized multicenter comparison of in situ and reversed vein infrapopliteal bypasses." J Vasc Surg 13(2): 189-97; discussion 197-9.
24. Gupta SK et al. (1991). "Prospective, randomized comparison of ringed and nonringed polytetrafluoroethylene femoropopliteal bypass grafts: a preliminary report." J Vasc Surg 13(1): 163-72.

1. Malmstedt, J., R. Takolander, et al. (2005). "A randomized prospective study of valvulotome efficacy in in situ reconstructions." Eur J Vasc Endovasc Surg 30(1): 52-6.
OBJECTIVES: To compare the efficacy of valvulotomes during in situ bypass surgery. DESIGN: A randomized prospective blinded study. MATERIALS AND METHODS: Thirty PAD patients scheduled for infrainguinal greater saphenous vein bypass were randomized to use of adjustable or fixed valvulotomes for valve destruction. Valvulotomy was performed after construction of the proximal anastomosis. The efficacy of valve destruction was determined by angioscopy after completion of the distal anastomosis by a separate blinded examiner. RESULTS: A total of 123 valves were evaluated, 61 after use of an adjustable and 62 with a fixed valvulotome. There was no difference (p =.88) in number of retained valves between the two groups (n = 16, 17, respectively). The majority of incompletely destroyed valves were found in the proximal parts of the graft (46%, 13 out of 28). The primary patency at 30 days was 100 and 79%, respectively, p =.09). CONCLUSIONS: No significant difference in efficacy between valvulotomes was found. Both types tend to miss a large proportion of proximal valves.

2. Schouten, O., M. T. Hoedt, et al. (2005). "End-to-end versus end-to-side distal anastomosis in femoropopliteal bypasses; results of a randomized multicenter trial." Eur J Vasc Endovasc Surg 29(5): 457-62.
OBJECTIVE: To compare end-to-side (ETS) and end-to-end (ETE) distal anastomoses for femoropopliteal bypasses. DESIGN: Prospective, randomized, multicenter trial. METHODS: Patients from 14 centers were randomized to either ETS or ETE distal anastomosis, with stratification according to center and four categories: venous and prosthetic above knee bypass, and venous and prosthetic below knee bypass. Follow-up, with history, physical examination, ankle-brachial pressure index and duplex scan was performed at 3 months, 6 months and every 6 months thereafter until 36 months postoperatively. RESULTS: A total of 328 femoropopliteal bypass operations were performed in 274 patients. Due to anatomical considerations at the time of surgery, 15 procedures (4.6%) were excluded from further analysis. Patient characteristics, cardiovascular risk factors, Rutherford classification and number of open run-off vessels were similar for both groups. Primary patency was 75 vs 74%, 65 vs 66% and 63 vs 55% for ETE vs ETS after 1, 2 and 3 years, respectively, (p = 0.26). During follow up major amputations were necessary in 20 ETE bypasses and in nine ETS bypasses (p = 0.028). CONCLUSION: ETE distal anastomosis infemoropopliteal bypasses does not improve patency compared to ETS anastomosis. Major amputations, after failure of the bypass, were required more frequently for ETE distal anastomoses.

3. Panneton, J. M., L. H. Hollier, et al. (2004). "Multicenter randomized prospective trial comparing a pre-cuffed polytetrafluoroethylene graft to a vein cuffed polytetrafluoroethylene graft for infragenicular arterial bypass." Ann Vasc Surg 18(2): 199-206.
Poor patency of synthetic grafts for infragenicular revascularization has led to use of distal vein patches or cuffs. The aim of this study was to compare the distally widened Distaflo PTFE graft, which mimics a vein cuff, with a PTFE graft with distal vein modification. In this prospective, randomized, multicenter trial we compared use of a precuffed PTFE graft wit that of PTFE grafts with distal vein modification for infragenicular revascularization in patients with critical limb ischemia without saphenous vein. Study end points were primary and secondary patency and limb salvage rates at 2 years. From January 28,1999 to November 1, 2000, 104 patients were enrolled in 10 North American centers. Thirteen were excluded for protocol violation. Ninety-one bypasses were performed in 89 patients with a mean age of 73 years (range 47-90). By randomization, 47 bypasses were done with the precuffed graft and 44 with PTFE graft with vein cuff. Both groups were comparable for comorbidities and operative variables, except for a higher incidence of acute ischemia in the precuffed group (19% vs. 4.5%, p = 0.03). Bypass was a redo procedure in 53% and was performed at the infrapopliteal vessels in 79%. Operative mortality was 2.2% (2/91). Mean follow-up was 14 months (range 1-30). At 1 and 2 years, primary patency was 52% and 49% for the precuffed group and 62% and 44% for the vein cuffed group, respectively (p = 0.53). At 1 year and 2 years, the limb salvage rate was 72% and 65% for the precuffed group and 75% and 62% in the vein cuffed group (p = 0.88). Although numbers are small and follow-up short, this midterm analysis shows similar results for the Distaflo precuffed grafts and PTFE grafts with vein cuff. A precuffed graft is a reasonable alternative conduit for infragenicular reconstruction in the absence of saphenous vein and provides favorable limb salvage.

4. Ballotta, E., L. Renon, et al. (2004). "Prospective randomized study on reversed saphenous vein infrapopliteal bypass to treat limb-threatening ischemia: common femoral artery versus superficial femoral or popliteal and tibial arteries as inflow." J Vasc Surg 40(4): 732-40.
PURPOSE: Use of inflow sources distal to the common femoral artery (CFA) for bypass to infrapopliteal arteries is a compromise measure when the length of the vein is not adequate. The purpose of this study was to compare the clinical outcome of vein infrapopliteal bypass arising from the CFA and from the distal superficial femoral or popliteal and tibial arteries in patients with limb-threatening ischemia. METHODS: Over 13 years, 160 vein infrapopliteal vein bypass procedures (160 patients) were randomized into 2 groups, 80 with inflow arising from the CFA (group 1) and 80 with inflow from below the CFA (group 2). Patency and limb salvage rates were assessed with the Kaplan-Meier method. All patients underwent graft surveillance at discharge and at 30 days and 6 months after surgery, then every 6 months thereafter. Follow-up ranged from 30 days to 127 months (mean, 49 months). RESULTS: Groups were similar with regard to age, sex, and most atherosclerotic risk factors. Gangrene as an indication for surgery was statistically more frequent in group 1 (73.7% vs 48.7%; P =.002), whereas nonhealing ulcer and rest pain were statistically more frequent in group 2 (respectively, 51.2% vs 25%; P =.001 and 46.2% vs 28.7%; P =.03). No patients died during the perioperative (30 days) period. At 1, 3, and 5 years patency and limb salvage rates were comparable between groups, tending toward significance for the 5-year primary patency rate (73% vs 57%; P =.08). CONCLUSIONS: In the absence of significant proximal disease, infrapopliteal revascularization arising distal to the CFA can ensure patency and limb salvage rates statistically similar to those with use of the CFA. Moreover, procedures arising distal to the CFA required fewer graft revisions to maintain patency of failing grafts.

5. Devine, C. and C. McCollum (2004). "Heparin-bonded Dacron or polytetrafluorethylene for femoropopliteal bypass: five-year results of a prospective randomized multicenter clinical trial." J Vasc Surg 40(5): 924-31.
OBJECTIVE: Dacron was largely abandoned for femoropopliteal bypass 30 years ago, because better patency rates were achieved with saphenous vein. Despite the range of potential prosthetics, polytetrafluoroethylne (PTFE) clearly predominates in current femoropopliteal practice. We compared heparin-bonded Dacron (HBD) with PTFE in a randomized multicenter clinical trial. METHOD: Over 28 months, 209 patients (179 above-knee disease, 30 below-knee disease) were randomized to receive HBD (n = 106) or PTFE (n = 103) grafts. Aspirin, 300 mg/d, was started before surgery, and was continued if tolerated. RESULTS: At follow-up for a minimum of 5 years (mean, 76 months; range, 60-89 months), 37 patients (17.7%) had died with patent grafts and 121 (58%) grafts were occluded. Primary patency rate, measured with Kaplan-Meier survival analysis, was 46% (95% confidence interval [CI], 35%-57%) at year 5 for HBD, compared with 35% for PTFE (CI, 25%-45%; P <.055). Long-term patency was achieved in only 4 of 78 interventions performed in 55 thrombosed grafts. Secondary patency rate for HBD was 47% (CI, 36%-58%), and for PTFE was 36% (CI, 26%-46%). Risk factors for arterial disease did not significantly influence prosthetic patency. Major limb amputation was necessary in 9 patients with HBD grafts and 20 patients with PTFE grafts (P <.025). Two amputations in the HBD group and 8 amputations in the PTFE group were in patients undergoing bypass surgery to treat claudication only. Limb salvage rate was 86% (CI, 77%-95%) and 74% (CI, 64%-84%), respectively. CONCLUSIONS: Significantly better patency rates were achieved with HBD than with PTFE at 3 years (P <.044), but the difference was no longer statistically significant at 5 years (P <.055). The incidence of major limb amputation, however, was significantly greater (P <.025) in the PTFE group compared with the HBD group at both 3 and 5 years of follow-up.

6. Griffiths, G. D., J. Nagy, et al. (2004). "Randomized clinical trial of distal anastomotic interposition vein cuff in infrainguinal polytetrafluoroethylene bypass grafting." Br J Surg 91(5): 560-2.
BACKGROUND: The aim was to examine the effect of a Miller vein cuff at the distal anastomosis on the medium- to long-term patency and limb salvage rates of femoral to above-knee and femoral to below-knee popliteal artery polytetrafluoroethylene (PTFE) bypasses. METHODS: This study involved extended follow-up of the original cohort of patients included in a previously reported multicentre randomized clinical study. Outcome measures were bypass graft patency and limb salvage. RESULTS: Two hundred and sixty-one bypass operations were originally randomized. For this study, full data were available on 235 (120 with a Miller cuff, 115 without). The cumulative 5-year patency rate for above-knee bypasses with a Miller cuff was 40 per cent, compared with 42 per cent for non-cuffed bypasses (P = 0.702). The cumulative 3-year patency rate for below-knee bypasses with a Miller cuff was 45 per cent, compared with 19 per cent for non-cuffed bypasses (P = 0.018). A Miller cuff had no significant effect on limb salvage for above-knee or below-knee bypasses. CONCLUSION: Three-year patency rates of femoral to below-knee popliteal PTFE bypasses were improved by a Miller cuff. Miller cuffs had no effect on patency rates for femoral to above-knee popliteal bypasses at 5 years and did not improve limb salvage in either group.

7. Klinkert, P., A. Schepers, et al. (2003). "Vein versus polytetrafluoroethylene in above-knee femoropopliteal bypass grafting: five-year results of a randomized controlled trial." J Vasc Surg 37(1): 149-55.
OBJECTIVE: Controversy still exists whether polytetrafluoroethylene is equivalent to vein as bypass graft material for the above-knee femoropopliteal bypass. Therefore, a prospective randomized trial was performed to compare vein with polytetrafluoroethylene for femoropopliteal bypasses with the distal anastomosis above the knee. METHODS: Between January 1993 and December 1996, 151 above-knee femoropopliteal bypasses were performed. The indications for operation were severe claudication in 120 cases, rest pain in 20 cases, and ulceration in 11 cases. After randomization, 75 reversed saphenous venous bypasses and 76 polytetrafluoroethylene bypasses were performed. RESULTS: No perioperative mortality was seen, and 5% of the patients had minor infections of the wound, not resulting in loss of the bypass, the limb, or life. After 5 years, 38% of the patients had died and 7% were lost to follow-up. Only once was the saphenous vein necessary for coronary artery bypass grafting. Primary patency rates after 5 years were 75.6% for venous bypass grafts and 51.9% for polytetrafluoroethylene grafts (P =.035). Secondary patency rates were 79.7% for vein and 57.2% for polytetrafluoroethylene bypasses (P =.036). In the venous group, 14 bypasses failed, leading to five new bypasses. In the polytetrafluoroethylene group, 29 bypasses failed, leading to 16 reinterventions. For these 16 new bypasses, in four cases, the ipsilateral preserved saphenous vein was used. In both groups, one above-knee amputation and one below-knee amputation had to be performed. CONCLUSION: We conclude after 5 years of follow-up of this randomized controlled trial that a bypass with saphenous vein has better patency rates at all intervals and needs fewer reoperations. Saphenous vein should be the graft material of choice for above-knee femoropopliteal bypasses and should not be preserved for reinterventions. Polytetrafluoroethylene is an acceptable alternative if the saphenous vein is not available.

8. Ballotta, E., L. Renon, et al. (2003). "Prospective randomized study on bilateral above-knee femoropopliteal revascularization: Polytetrafluoroethylene graft versus reversed saphenous vein." J Vasc Surg 38(5): 1051-5.
OBJECTIVE: Some controversy exists as to whether polytetrafluoroethylene (PTFE) is equivalent to reversed saphenous vein (SV) as bypass graft material for above-knee femoropopliteal revascularization. We compared the 5-year patency rate with reversed SV and PTFE grafts in patients with claudication who underwent bilateral above-knee femoropopliteal revascularization. METHODS: Between January 1994 and December 1997, 51 patients (102 limbs) with bilateral disabling claudication due to superficial femoral artery occlusion underwent above-knee femoropopliteal bypass grafting, with SV in one limb and PTFE graft in the other limb. Patients were randomly selected for sequential surgical treatment with either SV-PTFE or PTFE-SV. Kaplan-Meier analysis was used to estimate patency rate, and various factors were analyzed to ascertain any association with revascularization failure. RESULTS: There was no perioperative (30 day) limb loss or death, but five late deaths (late survival rate, 90%). Mean follow-up was 59 months. In the SV group, three bypass grafts failed, requiring repeat operation in only one patient. In the PTFE group, eight bypass grafts failed, leading to five repeat operations. There was no statistically significant difference in primary "assisted" patency rate for the two grafts: 100%, 98%, and 94% for SV grafts, and 96%, 84%, and 84% for PTFE grafts (P =.09), after 1, 3, and 5 years, respectively. CONCLUSIONS: The overall results of this randomized study show that SV and PTFE grafts have a statistically comparable patency rate when used above the knee in patients with claudication. Use of SV, however, leads to fewer occlusions and repeat operations.

9. Kreienberg, P. B., R. C. Darling, 3rd, et al. (2002). "Early results of a prospective randomized trial of spliced vein versus polytetrafluoroethylene graft with a distal vein cuff for limb-threatening ischemia." J Vasc Surg 35(2): 299-306.
OBJECTIVE: Single-piece vein remains the conduit of choice in patients who need bypass grafting for limb salvage. When this option is not available, two of the remaining options are prosthetic bypass graft or several segments of vein spliced together. In this study, we compare spliced vein bypass grafting versus polytetrafluoroethylene grafting with a distal vein cuff in patients with limb-threatening ischemia. METHODS: Between 1996 and 2000, 39 bypass grafting procedures in 36 patients were performed for limb-threatening ischemia. These procedures were prospectively randomized to either spliced vein bypass grafting (spliced group, 19 bypass grafts) or polytetrafluoroethylene grafting with a distal vein cuff (cuff group, 20 bypass grafts). All the patients in the cuff group underwent anticoagulation therapy with warfarin sodium after surgery. The inclusion criteria included: no single-piece vein option for bypass grafting, adequate vein for splice, no composite sequential option, and limb-threatening ischemia. The demographics were similar between the two groups. RESULTS: The primary patency rate at 2 years was 44% and 49% for the spliced and cuff groups, respectively. In the spliced group, seven of 19 bypass grafts underwent revision in the follow-up period, and two of 20 cuffed bypass grafts were successfully revised. The secondary patency rate was 87% and 59% (P <.05), with limb salvage rates of 94% and 85% for spliced and cuff groups, respectively. Four patients in the spliced vein group needed reoperation for wound complications related to vein harvest. One polytetrafluoroethylene graft needed removal for infection. Two early mortalities occurred in the spliced group, one from myocardial infarction and one from stroke. The overall survival rate at 2 years between the two groups was 67% and 100% for the spliced and cuff groups, respectively (P <.05). CONCLUSION: Although this is a preliminary report, it appears that both spliced vein bypass grafting and polytetrafluoroethylene bypass grafting with a distal vein cuff produce acceptable limb salvage rates. The secondary patency rate for spliced vein is better, but these bypass grafts more often need revision or reoperation for wound complications.

10. Devine, C., B. Hons, et al. (2001). "Heparin-bonded Dacron or polytetrafluoroethylene for femoropopliteal bypass grafting: a multicenter trial." J Vasc Surg 33(3): 533-9.
BACKGROUND: Dacron (polyester fiber) was largely abandoned for femoropopliteal bypass grafts 30 years ago because saphenous vein achieved better patencies. However, in patients taking aspirin, patency in above-knee femoropopliteal bypass grafts has recently been shown to be equivalent to that with saphenous vein. We compared heparin-bonded Dacron (HBD) and polytetrafluoroethylene (PTFE) in a randomized multicenter trial including below-knee popliteal or tibioperoneal trunk bypass graft where the long saphenous vein was absent or inadequate. METHODS: Over 28 months, 209 patients undergoing femoropopliteal bypass grafts (180 above-knee, 29 below-knee) were randomized to HBD (n = 106) or PTFE (n = 103). Each patient was given aspirin (300 mg/d) before surgery, and this continued unless the patient had intolerance to the aspirin. RESULTS: The mean follow-up was 42 months (range, 28-55). Fifteen (7.1%) patients died with patent grafts, and three (1.4%) infected grafts were removed. Patency (measured with Kaplan-Meier survival analysis) at 1, 2, and 3 years for HBD was 70%, 63%, and 55% compared with 56%, 46%, and 42%, respectively, for PTFE (P =.044). A total of 67 secondary interventions were performed on 48 thrombosed grafts; long-term patency was achieved in only three. Risk factors for arterial disease did not significantly influence patency. Amputations have been performed in 23 patients, six after HBD and 17 after PTFE bypass grafts (P =.015). CONCLUSIONS: HBD achieved better patency than PTFE, which carried a high risk of subsequent amputation.

11. Post, S., T. Kraus, et al. (2001). "Dacron vs. polytetrafluoroethylene grafts for femoropopliteal bypass: a prospective randomised multicentre trial." Eur J Vasc Endovasc Surg 22(3): 226-31.
OBJECTIVES: To compare the patency of PTFE (Polytetrafluoroethylene) and unsealed knitted Dacron femoro-popliteal bypasses. DESIGN: Multi-centre prospective randomised trial. MATERIALS AND METHODS: Of 203 patients randomised, 194 were included in the final analysis (103 Dacron grafts and 91 PTFE grafts). The median follow-up was 36 months (range: 6-72 months); the distal anastomosis was above-knee in 141 and below-knee in 53 cases. Univariate comparisons of patency were made by the Kaplan-Meier method, multivariate calculations on the effects of covariables by a Cox regression analysis. RESULTS: There was no difference regarding primary and secondary patency or limb salvage between Dacron and PTFE. The primary 3-year patency for Dacron grafts was 64% (95% confidence interval [C.I.] 55-74%) and for PTFE grafts 61% (C.I. 49-72%). The corresponding 3-year secondary patency was 81% (C.I. 73-89%) and 75% (C.I. 65-86%) respectively, the limb salvage rate 90% (C.I. 84-96%) and 91% (C.I. 84-97%). Upon multivariate analysis below-knee anastomosis was the principal independent predictor of primary graft failure (risk ratio 1.7 [C.I. 1.05-2.8]), impaired secondary patency was associated with infragenicular bypass (risk ratio 3.3 [C.I. 1.8-6.3]) and distal gangrene (risk ratio [C.I. 1.01-3.8]p=0.048), major amputation was independently predicted by below-knee bypass, tissue necrosis, and poor run-off index. CONCLUSIONS: PTFE and Dacron are equally suitable for femoro-popliteal bypass.

12. Burger, D. H., A. P. Kappetein, et al. (2000). "A prospective randomized trial comparing vein with polytetrafluoroethylene in above-knee femoropopliteal bypass grafting." J Vasc Surg 32(2): 278-83.
OBJECTIVE: Despite many clinical studies, there is still uncertainty as to whether venous material is superior to polytetrafluoroethylene for femoropopliteal reconstruction proximal to the knee joint. Supported by early satisfactory results with thin-walled, stretched polytetrafluoroethylene for suprageniculate bypass grafts, a prospectively randomized clinical trial was designed to evaluate the effectiveness of reversed saphenous vein in comparison with that of polytetrafluoroethylene in above-knee arterial reconstruction. METHODS: In a 3-year period, 151 above-knee femoropopliteal bypass graft operations were performed in 136 patients (77 male, 59 female). The indication for operation was severe claudication in 120 cases, rest pain in 20 cases, and ulceration in 11 cases. For the bypass graft, a reversed saphenous vein was used in each of 75 cases, and a polytetrafluoroethylene prosthesis was used in each of 76 cases. Preoperative risk factors were diabetes (24%), a history of myocardial infarction (23%), and current status with respect to smoking (74%). There was no hospital mortality; 5% of patients had minor postoperative complications. RESULTS: After 2 years, the primary patency was 83% for saphenous vein and 67% for polytetrafluoroethylene (P =.065); the secondary patency was 83% for saphenous vein and 77% for polytetrafluoroethylene (P =.298). During a follow-up period of 2 years, we found no statistically significant difference in primary and secondary patency between saphenous vein and polytetrafluoroethylene. We found no predictive factor for occlusion of either bypass graft. CONCLUSION: The use of polytetrafluoroethylene above the knee is a reasonable alternative in femoropopliteal bypass grafting that is associated with acceptable short-term patency rates.

13. Johnson, W. C. and K. K. Lee (2000). "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." J Vasc Surg 32(2): 268-77.
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.

14. Green, R. M., W. M. Abbott, et al. (2000). "Prosthetic above-knee femoropopliteal bypass grafting: five-year results of a randomized trial." J Vasc Surg 31(3): 417-25.
PURPOSE: This trial was designed to identify factors affecting patency rates of primary prosthetic above-knee femoropopliteal bypass grafts at 5 years. METHODS: A multi-institutional, prospective trial randomized 240 patients to compare patency rates of Gore-tex and Hemashield above-knee femoropopliteal bypass grafts at 5 years. Univariate comparisons of patency between levels of each prognostic variable were made with the Kaplan-Meier method. Variables that had a univariate P value less than.25 or those known to be important were submitted to a Cox regression analysis. RESULTS: The patient survival rate at 5 years was 59.4%. There were no differences in primary or secondary patency rates at 5 years between the two graft materials (primary, 45% vs 43% and secondary, 68% vs 68%). The risk for graft occlusion was significantly increased for patients younger than 65 years (2.1; P =.001) and for grafts with a diameter less than 7 mm (1.65; P =.0219). Variables with no apparent independent effect on patency rates were smoking status, runoff, diabetes mellitus, sex, presenting symptoms, and postoperative treatment with aspirin or Coumadin. Noninvasive test results were not predictive of subsequent graft function. CONCLUSION: Although the type of prosthetic used for above-knee femoropopliteal bypass grafts does not affect 5-year patency rates, age and graft size do influence results. These factors should be considered before a prosthetic bypass grafting procedure. Furthermore, these data should serve as a contemporary standard, with which evolving and conventional procedures can be compared.

15. Robinson, B. I., J. P. Fletcher, et al. (1999). "A prospective randomized multicentre comparison of expanded polytetrafluoroethylene and gelatin-sealed knitted Dacron grafts for femoropopliteal bypass." Cardiovasc Surg 7(2): 214-8.
PURPOSE: To compare graft patency between expanded polytetrafluoroethylene (PTFE) and gelatin-sealed knitted Dacron for femoropopliteal bypass. METHODS: A prospective, multicentre trial was performed in 108 patients randomized to receive either a PTFE or Dacron prosthetic graft. Distal anastomosis was above knee in 75 and below knee in 33 patients. RESULTS: Primary patency at 1, 2 and 3 years was 72, 52 and 52% for PTFE, and 70, 56 and 47% for Dacron (P = 0.87). Secondary patency at 1, 2 and 3 years was 74, 54 and 54% for PTFE and 78, 70 and 53% for Dacron (P = 0.39). The most significant predictors of early graft failure were poor vessel run-off (P = 0.04) and critical limb ischaemia (P = 0.04). CONCLUSION: There was no difference in graft patency between PTFE and Dacron for femoropopliteal bypass.

16. Hamsho, A., D. Nott, et al. (1999). "Prospective randomised trial of distal arteriovenous fistula as an adjunct to femoro-infrapopliteal PTFE bypass." Eur J Vasc Endovasc Surg 17(3): 197-201.
OBJECTIVES: To compare graft patency and limb salvage rate following femoro-infrapopliteal bypass using ePTFE grafts with and without the addition of adjuvant arterio-venous fistula. DESIGN: A prospectively randomised controlled trial. MATERIALS: Patients referred to two teaching hospital vascular surgery units in the U.K. for the treatment of critical limb ischaemia. METHODS: Eighty-seven patients (M:F; 2.3:1) undergoing 89 femoro-intrapopliteal bypass operations with ePTFE grafts for critical limb ischaemia were randomly allocated to have AVF included in the operative procedure (n = 48) or to a control group without AVF (n = 41). An interposition vein-cuff was incorporated at the distal anastomosis in all patients. RESULTS: The cumulative rates of primary patency and limb salvage at 1-year after operation for patients with AVF were 55.2% and 54.1% compared to 53.4% and 43.2%, respectively, for the control group. The differences between the AVF and control groups did not reach statistical significance, in terms of either graft patency or limb salvage, at any stage after operation (Log-Rank test). CONCLUSIONS: AVF confers no additional significant clinical advantage over interposition vein cuff in patients having femoro-infrapopliteal bypass with ePTFE grants for critical limb ischaemia.

17. Stonebridge, P. A., R. J. Prescott, et al. (1997). "Randomized trial comparing infrainguinal polytetrafluoroethylene bypass grafting with and without vein interposition cuff at the distal anastomosis. The Joint Vascular Research Group." J Vasc Surg 26(4): 543-50.
PURPOSE: A multicenter randomized prospective study was undertaken to determine whether an interposition vein cuff improved the short-term and medium-term patency and limb salvage rates of femoral-above-knee and femoral-below-knee popliteal artery polytetrafluoroethylene (PTFE) bypass procedures. METHODS: Two hundred sixty-one bypass operations were randomized (133 to vein cuff and 128 to no vein cuff). One hundred fifty grafts were to the above-knee popliteal artery, 96 to the below-knee popliteal artery, and 15 to tibial vessels. The median follow-up was 617 days. RESULTS: The 12-month patency rates for cuffed and uncuffed above-knee popliteal artery PTFE bypass grafts were 80% and 84%, and the 2-year patency rates were 72% and 70%, respectively. The patency rates for bypass grafts to the below-knee popliteal artery at 12 months were 80% and 65% and at 2 years 52% and 29%, respectively (p = 0.03). At the below-knee site, this was reflected in 24-month difference in limb salvage rates of 84% and 62%, respectively (p = 0.08). CONCLUSIONS: There was no improvement in the patency rate with the use of a distal anastomosis interposition vein cuff in femoral-above-knee popliteal PTFE bypass grafts, but there was a statistically significant advantage when PTFE bypass grafts were anastomosed to the popliteal artery below the knee.

18. Watelet, J., P. Soury, et al. (1997). "Femoropopliteal bypass: in situ or reversed vein grafts? Ten-year results of a randomized prospective study." Ann Vasc Surg 11(5): 510-9.
One hundred femoropopliteal bypass procedures performed in 91 patients between October 1980 and January 1985 were randomly divided into two statistically comparable groups including 50 in situ vein grafts and 50 reversed vein grafts. The indication for bypass was chronic critical ischemia in 97% of cases. The lower anastomosis was made on the distal popliteal artery in 75% of cases. Follow-up ranged from 10 years (for the last patient included) to 14 years. Three patients have been lost to follow-up. Median survival was 54 months in the in situ graft group and 76.5 months in the reversed graft group. Actuarial survival at 10 years was 30.8% in the in situ graft group and 29.5% in the reversed graft group. Actuarial limb salvage at 10 years was 73.5% in the in situ graft group and 74.4% in the reversed graft group. Graft occlusion was observed in 10 cases during the perioperative period (six in the in situ graft group and four in the reversed graft group) and in 19 cases during the late postoperative period (12 in the in situ graft group and seven in the reversed graft group). Reoperation during follow-up was required in 13 cases in the in situ graft group (11 patients) and in nine cases in the reversed graft group (five patients). Discounting residual arteriovenous fistulas (FAV) (five ligations in four patients), the incidence of lesions involving the bypass and anastomoses threatening graft patency was 6% in the in situ graft group and 8% in the reversed graft group. Actuarial primary patency at 10 years was 41.7% in the in situ graft group and 64.5% in the reversed graft group (p < 0.05). Actuarial secondary patency at 10 years was 64.8% in the in situ graft group and 70.2% in the reversed graft group (NS). As a function of vein diameter, actuarial secondary patency at 10 years in the in situ graft group was 37.5% for bypasses using veins with a diameter of 4 mm or less and 80.6% for bypasses using veins larger than 4 mm (p < 0.05). In the reversed graft group the patency rate was 71.2% for bypasses using veins with a diameter of 4 mm or less and 65.5% for bypasses using veins larger than 4 mm. In addition to requiring a training period the in situ technique raises the problem of valve removal especially for small diameter veins. The absence of these disadvantages makes the reversed technique the procedure of choice for femoropopliteal bypass.

19. Abbott, W. M., R. M. Green, et al. (1997). "Prosthetic above-knee femoropopliteal bypass grafting: results of a multicenter randomized prospective trial. Above-Knee Femoropopliteal Study Group." J Vasc Surg 25(1): 19-28.
PURPOSE: There are excellent arguments in favor of the preferential use of prosthetic grafts above the knee for the treatment of infrainguinal occlusive disease. This approach has been popularized on the basis of the seemingly acceptable results when using polytetrafluoroethylene (PTFE). However, in many centers, knitted Dacron polyester has been used in these patients, and there are several studies that show equivalent and, in some, superior results with Dacron when compared with PTFE. The purpose of this study was to examine these results in a definitive way. METHODS: A randomized prospective trial in eight clinical academic centers in the United States and Canada was initiated in 1991. Two hundred forty-four patients eligible for such a study, by virtue of criteria extant in each institution at the time, were centrally randomized. They underwent placement of either a knitted Dacron polyester graft impregnated with collagen or a thin-wall expanded reenforced PTFE graft to the above-knee popliteal artery, usually from the common femoral artery. They were frequently observed by protocol for as long as 5 years by a physical examination noninvasive hemodynamic study, including duplex scanning in many instances. Continuing patency was noted, as were other potential adverse outcome events. The data were analyzed by the log-rank test for cumulative patency and expressed as Kaplan-Meier curves. Data were further analyzed with a Cox proportional hazards model. RESULTS: There were no differences in graft groups in demographic or comorbid factors. The procedural mortality rate was zero, and the morbidity rate was low (6.5%). The long-term patient survival rate was excellent (77% at 3 years). At the end of these years, no statistical significance in primary or secondary patency rates was observed between the two grafts (primary patency rate, 62% +/- 14.4% for Dacron; 57% +/- 15.5% for PTFE). No unexpected adverse outcomes on limb status were noted. Patency rates in both graft groups were inferior in patients who received small grafts (5 to 6 mm vs 7 to 8 mm; hazards ratio, 4.15) and younger (<65 years) smoking patients. CONCLUSIONS: The fact that these two prosthetic grafts performed in equivalent fashion in a controlled, well-conducted prospective study is not surprising in spite of the previous work that suggested differences. If the preferential use of synthetic bypass grafts above the knee is to be used, it should be restricted to older nonsmokers with favorable anatomy. In that instance, the choice of graft material will depend on handling characteristics and cost. Above-knee prostheses should be only selectively used in younger, smoking patients, and graft size should be carefully considered in patients who undergo this operation.

20. Aalders, G. J. and T. J. van Vroonhoven (1992). "Polytetrafluoroethylene versus human umbilical vein in above-knee femoropopliteal bypass: six-year results of a randomized clinical trial." J Vasc Surg 16(6): 816-23; discussion 823-4.
In a prospective, randomized trial 6 mm polytetrafluoroethylene (PTFE) and 6 mm human umbilical vein (HUV) were compared in above-knee femoropopliteal bypass grafting. In claudicants a prosthetic graft was used intentionally, in limb-salvage cases only when autologous vein was insufficient. Ninety-six extremities were randomized (49 PTFE and 47 HUV). Operative indication was disabling claudication in 77 and limb salvage in 19 extremities. The two groups were comparable as to preoperative risk factors and operative and postoperative treatment. Median follow-up was 76 months (range 47 to 91 months), during which 23 patients died of nonrelated causes with functioning grafts. Thirty-eight grafts failed (33 because of occlusion and five for other reasons). At 6 years the primary patency rate was 38.7% in the PTFE group and 71.4% in the HUV group (p < 0.001). Corresponding rates for secondary patency at 6 years were 51.4% and 76.4% (p < 0.005).

21. Moody, A. P., P. R. Edwards, et al. (1992). "In situ versus reversed femoropopliteal vein grafts: long-term follow-up of a prospective, randomized trial." Br J Surg 79(8): 750-2.
In a prospective, randomized trial, 226 patients undergoing femoropopliteal bypass for lower limb ischaemia were allocated to reversed (123 patients) or in situ (103) techniques. The groups were comparable for age, sex, incidence of diabetes, and indications for surgery. Eleven veins were rejected at operation, nine in the reversed group and two in the in situ group, leaving 114 reversed and 101 in situ grafts for study. Cumulative patency rates were not significantly different between reversed and in situ grafts at any time up to 6 years after operation, with primary patency rates at 1, 3 and 5 years of 84.8, 69.5 and 62.4 per cent for reversed grafts and 79.9, 71.2 and 63.5 per cent for in situ grafts. Small vein grafts (< 4 mm in diameter) were associated with patency rates at 1, 3 and 5 years of 63.5, 46.7 and 36.0 per cent compared with 93.9, 82.5 and 75.9 per cent for vein grafts > or = 4 mm in diameter (P < 0.002, log rank test). The patency rates of small veins employed in situ and reversed were similar. The in situ technique confers neither short- nor long-term advantage over reversed vein grafting for femoropopliteal bypass.

22. McCollum, C., G. Kenchington, et al. (1991). "PTFE or HUV for femoro-popliteal bypass: a multi-centre trial." Eur J Vasc Surg 5(4): 435-43.
Despite wide clinical experience the choice between human umbilical vein (HUV) or polytetrafluoroethylene (PTFE) when the saphenous vein is inadequate remains unclear. In a multi-centre trial of 801 femoro-popliteal bypasses, autogenous vein could not be used in 252 (31%), of which 191 were randomised to either HUV or PTFE and started on aspirin 300 mg plus dipyridamole 150 mg (ASA + DPM) twice daily. Graft patency measured objectively by independent trial coordinators was expressed on an "intention to treat" basis by life table and analysed statistically by log rank and confidence intervals (95% CI). Overall, 101 grafts failed and cumulative patency was 53% (45-61%) at 3 years compared with 60% (55-65%) in 549 vein grafts. Prosthetic bypass patency above knee was 65% (55-75%); markedly better than 35% (23-47%) below knee (p less than 0.001) and comparable with 62% (55-69%) in 217 above knee saphenous vein grafts. Most failures occurred early at a rate of 52/1000 patient-months in the first 3 months (43/1000 for vein) falling to 21/1000 by 6 to 12 months and around 10/1000 subsequently. Randomisation produced comparable groups of 87 HUV and 104 PTFE grafts. Cumulative primary patency for HUV was 68, 63 and 57% at 1, 2 and 3 years, respectively compared with 61, 56 and 48% for PTFE with wide confidence intervals for the difference at 3 years (-20 to 38%, p = 0.27).(ABSTRACT TRUNCATED AT 250 WORDS)

23. Wengerter, K. R., F. J. Veith, et al. (1991). "Prospective randomized multicenter comparison of in situ and reversed vein infrapopliteal bypasses." J Vasc Surg 13(2): 189-97; discussion 197-9.
We have performed a prospective, randomized, multicenter study to compare in situ and reversed vein grafts for long limb salvage bypasses from the proximal thigh to an infrapopliteal artery. Three hundred eighty-four patients required an infrapopliteal bypass for critical lower extremity ischemia. Of these, 259 were excluded because a short vein bypass was performed or because the vein was considered inadequate. The remaining 125 patients had a randomized vein bypass, 63 reversed, 62 in situ. The two groups were similar with regard to risk factors, indications, graft dimensions, and outflow. Secondary patency at 30 months was similar for both techniques: reversed 67% +/- 9% (+/- SE); in situ 69% +/- 8%. For veins less than or equal to 3.0 mm in minimum distended diameter 24-month patency rates were 61% +/- 22% for 12 in situ veins and 37% +/- 29% for 10 reversed veins (p greater than 0.05). Angiographic evaluation of failing grafts revealed lesions similar in type and frequency in both types of grafts. These included focal (in situ, n = 4; reversed, n = 7) and diffuse vein hyperplasia (in situ, n = 2; reversed, n = 1), and inflow and outflow stenoses (in situ, n = 4; reversed, n = 3). The incidence of wound complications and the mortality rate were similar for the two groups. These data show no significant difference in overall patency rates for the two types of vein grafts at 2 1/2 years.(ABSTRACT TRUNCATED AT 250 WORDS)

24. Gupta, S. K., F. J. Veith, et al. (1991). "Prospective, randomized comparison of ringed and nonringed polytetrafluoroethylene femoropopliteal bypass grafts: a preliminary report." J Vasc Surg 13(1): 163-72.
Kinking and compression with knee flexion are thought to be one cause of failure of below-knee polytetrafluoroethylene femoropopliteal bypass. To prevent this problem polytetrafluoroethylene grafts externally supported with rigid rings have been developed. The present randomized, prospective study compared ringed and nonringed polytetrafluoroethylene grafts in 122 patients who underwent femoropopliteal bypass for severe limb ischemia. Patients were well matched for surgical indications and risk factors. There was no significant difference in the 3-year graft patency rate of ringed versus nonringed polytetrafluoroethylene femoropopliteal bypasses (74% vs 68%, p = 0.5). Similarly, no significant differences were found in the 3-year graft patency rates of ringed versus non-ringed above-knee (82% vs 74%, p = 0.5) or below-knee polytetrafluoroethylene femoropopliteal bypasses (68% vs 59%, p = 0.5). The 3-year graft patency rate of all above-knee polytetrafluoroethylene femoropopliteal bypasses was slightly greater than that of below-knee polytetrafluoroethylene femoropopliteal bypasses (76% vs 62%), but this difference was not statistically significant (p = 0.25). The 3-year limb salvage rate with ringed polytetrafluoroethylene grafts was 92% compared with 79% for nonringed polytetrafluoroethylene grafts, but this difference was not statistically significant (p = 0.25). Data to date from this study fail to support the recommendation that ringed polytetrafluoroethylene grafts be used preferentially over conventional polytetrafluoroethylene grafts in patients who require femoropopliteal bypass with a synthetic graft.