Meta-analysis of femoropopliteal bypass grafts for lower extremity arterial insufficiency

BACKGROUND: In femoropopliteal bypass surgery, the use of saphenous vein grafts is preferable, but synthetic grafts are widely used above the knee. The objective of this meta-analysis was to assess the long-term patency of femoropopliteal bypass grafts classified as above-knee polytetrafluoroethylene, above-knee saphenous vein, or below-knee saphenous vein. METHODS: Studies published from 1986 through 2004 were identified from electronic databases and reference lists; 73 articles contributed 1 or more series that used survival analysis, assessed femoropopliteal bypasses in one of the foregoing configurations, reported a 1-year graft patency rate, and included at least 30 bypasses. The series with a predominance of claudicant patients were included in meta-analysis C, and the series in which critical ischemia predominated were included in meta-analysis CI. Pooled survival curves of graft patency were constructed. RESULTS: In meta-analysis C, the pooled primary graft patency was 57.4% for above-knee polytetrafluoroethylene, 77.2% for above-knee vein, and 64.8% for below-knee vein at 5 years; there was a significant difference between above-knee grafts at 3, 4, and 5 years (P < .05). The corresponding pooled secondary graft patency was 73.2%, 80.1%, and 79.7%, respectively (P > .05). In meta-analysis CI, the pooled primary graft patency was 48.3% for above-knee polytetrafluoroethylene, 69.4% for above-knee vein, and 68.9% for below-knee vein at 5 years; there was a significant difference between above-knee grafts until 4 years (P < .05). The corresponding pooled secondary graft patency was 54.0%, 71.9%, and 77.8%, respectively, with a significant difference between above-knee grafts at 2, 3, and 4 years (P < .05). CONCLUSIONS: The great saphenous vein performs better than polytetrafluoroethylene in femoropopliteal bypass grafting and should be used whenever possible.     

Six-year prospective multicenter randomized comparison of autologous saphenous vein and expanded polytetrafluoroethylene grafts in infrainguinal arterial reconstructions

Autologous saphenous vein (ASV) and polytetrafluoroethylene (PTFE) grafts were compared in 845 infrainguinal bypass operations, 485 to the popliteal artery and 360 to infrapopliteal arteries. Life-table primary patency rates for randomized PTFE grafts to the popliteal artery paralleled those for randomized ASV grafts to the same level for 2 years and then became significantly different (4-year patency rate of 68% +/- 8% [SE] for ASV vs. 47% +/- 9% for PTFE, p less than 0.025). Four-year patency differences for randomized above-knee grafts were not statistically significant (61% +/- 12% for ASV vs. 38% +/- 13% for PTFE, p greater than 0.25) but were for randomized below-knee grafts (76% +/- 9% for ASV vs. 54% +/- 11% for PTFE, p less than 0.05). Four-year limb salvage rates after bypasses to the popliteal artery to control critical ischemia did not differ for the two types of randomized grafts (75% +/- 10% for ASV vs. 70% +/- 10% for PTFE, p greater than 0.25). Although primary patency rates for randomized and obligatory PTFE grafts to the popliteal artery were significantly different (p less than 0.025), 4-year limb salvage rates were not (70% +/- 10% vs. 68% +/- 20%, p greater than 0.25). Primary patency rates at 4 years for infrapopliteal bypasses with randomized ASV were significantly better than those with randomized PTFE (49% +/- 10% vs. 12% +/- 7%, p less than 0.001). Limb salvage rates at 3 1/2 years for infrapopliteal bypasses with both randomized grafts (57% +/- 10% for ASV and 61% +/- 10% for PTFE) were better than those for obligatory infrapopliteal PTFE grafts (38% +/- 11%, p less than 0.01). These results fail to support the routine preferential use of PTFE grafts for either femoropopliteal or more distal bypasses. However, this graft may be used preferentially in selected poor-risk patients for femoropopliteal bypasses, particularly those that do not cross the knee. Although every effort should be made to use ASV for infrapopliteal bypasses, a PTFE distal bypass is a better option than a primary major amputation.     

Vein versus polytetrafluoroethylene in above-knee femoropopliteal bypass grafting: five-year results of a randomized controlled trial

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.     

Heparin-bonded expanded polytetrafluoroethylene vascular graft for femoropopliteal and femorocrural bypass grafting: 1-year results

OBJECTIVE: Several prosthetic materials have been used for femoropopliteal bypass grafting in patients with peripheral vascular disease in whom a venous bypass is not possible. Expanded polytetrafluoroethylene (ePTFE) is the most commonly used, but patency results have not always equaled those achieved with vein, especially in below-knee reconstructions. This study assessed the performance of a new heparin-bonded ePTFE vascular graft that was designed to provide resistance to thrombosis and thereby decrease early graft failures and possibly prolong patency. METHOD: From June 2002 to June 2003, 86 patients (62 men and 24 women; mean age, 70 years; 99 diseased limbs) were enrolled prospectively in a nonrandomized, multicenter study of the heparin-bonded ePTFE graft. Fifty-five above-knee and 44 below-knee (including 21 femorocrural) procedures were performed. Follow-up evaluations consisted of clinical examinations, ultrasonographic studies, and distal pulse assessments. Patency and limb salvage rates were assessed by using life-table analyses. RESULTS: All grafts were patent immediately after implantation. There were no graft infections or episodes of prolonged anastomotic bleeding. During the 1-year follow-up, 10 patients died, 15 grafts occluded, and 5 major amputations were performed. The overall primary and secondary 1-year patency rates were 82% and 97%, respectively. The limb salvage rate in patients with critical limb ischemia (n = 41) was 87%. Primary patency rates according to bypass type were 84%, 81%, and 74% for above-knee femoropopliteal, below-knee femoropopliteal, and femorocrural bypasses, respectively; the corresponding secondary patency rates were 96%, 100%, and 100%. CONCLUSIONS: In this study, the heparin-bonded ePTFE graft provided promising early patency and limb salvage results, with no device-related complications, in patients with occlusive vascular disease. Longer-term and randomized studies are warranted to determine whether this graft provides results superior to those achieved with other prostheses, especially in patients at increased risk of early graft failure, such as those undergoing below-knee bypass and those with poor run-off or advanced vascular disease.     

Infrainguinal ePTFE vascular graft with bioactive surface heparin bonding. First clinical results

AIM: The ultimate aim of improved expanded polytetrafluoroethylene (ePTFE) vascular graft design is to achieve patency rates in femoropopliteal bypass grafting comparable with autologous saphenous vein grafts. Enhanced thromboresistance of the ePTFE material by bioactive surface heparin bonding is one conceivable path toward this goal. This retrospective study was performed to collect the first clinical data for a new ePTFE graft with bioactive surface heparin immobilization. METHODS: Between March 2003 and February 2004, 43 femoropopliteal or femorocrural ePTFE vascular prostheses with bioactive end-point immobilized heparin (Gore-Tex Propaten Vascular Graft), using the Car-meda BioActive Surface technology, were implanted in 40 patients. Twelve prostheses were implanted in above-knee and 31 in below-knee position. The indication for bypass grafting was limb-threatening ischemia in 88% of the patients. The mean follow-up was 16.6 months. RESULTS: The primary 1-year patency was 91% for above-knee bypass grafts and 92% for below-knee bypass grafts. The 2-year primary patency rate for above-knee bypass grafts was 68% and 81% for below-knee bypass grafts. Limb salvage was achieved in 98%. The perioperative mortality was 0%, but during follow-up 22% of the patients died with patent bypass grafts. CONCLUSIONS: While conventional ePTFE grafts, particularly in the below-knee position, have shown poor results even in the short-term, the bioactive heparinized ePTFE graft evaluated in this study provides patency rates comparable with autologous vein grafts. Because the influence of luminal heparin bonding is not only limited to thromboresistance but has impact on, amongst other elements, protein adsorption (thereby improving hemocompatibility), a continuous effect for long-term patency could also be expected.     

Randomized clinical trial of distal anastomotic interposition vein cuff in infrainguinal polytetrafluoroethylene bypass grafting

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.     

Long-term results of infrainguinal revascularization with polytetrafluoroethylene: a ten-year experience.

Two hundred fifty-eight patients underwent 322 infrainguinal revascularizations with use of polytetrafluoroethylene (PTFE) between 1978 and 1988. The indication was limb salvage in 190 (59%) reconstructions. Two hundred nineteen (68%) were above-knee, and 75 (23%) were below-knee femoropopliteal bypasses. Twenty-eight (8.6%) were femoral-infrapopliteal bypasses, all done for limb salvage. Follow-up ranged from 24 to 144 months (mean, 66 months). The perioperative mortality rate (1 to 30 days) was 3.4% (9 patients), with no significant difference according to indication (2.9% vs 3.7%). Actuarial primary patency at 8 years for the entire series of femoropopliteal bypasses was 53% (above knee 53%; below knee 39%; p less than 0.05), and improved with additional procedures for a secondary patency of 72%. Femoropopliteal bypasses done for severe claudication had an 8-year actuarial primary patency of 63%, compared with 38% for limb salvage (p less than 0.02). Actuarial limb salvage in the latter group at 8 years was 66%. Femoral-infrapopliteal reconstructions with PTFE had a significantly lower primary patency at 3 years (22%, with a 37% limb salvage). Sixty-four percent of the failures for all reconstructions (N = 111) occurred within 12 months, with remarkable stabilization of patency curves beyond that interval. This experience represents the largest reported series of PTFE reconstruction with longest follow-up to date and may serve as a basis for comparison of other conduits. These results suggest an important role for PTFE in femoropopliteal revascularization and a limited role of this prosthetic conduit in femoral-infrapopliteal arterial reconstructions.     

Results with heparin bonded polytetrafluoroethylene grafts for femorodistal bypasses

AIM: Expanded polytetrafluoroethylene (ePTFE) grafts are commonly used for femoropopliteal (FP) and femorocrural (FC) bypass grafting. Especially in below-knee (BK) reconstructions, patency is often inferior to the outcome in patients eligible for venous bypass grafting. This study assesses whether the Carmeda BioActive Surface (CBAS), which employs covalent end-point linkage to retain heparin on the device surface, as it is used on the Propaten vascular graft successfully, can prolong patency. METHODS: From June 2002 to December 2005, 138 patients (97 men and 41 women; mean age: 73 years) received the CBAS-ePTFE graft for 153 infrainguinal bypass procedures. Seventy-five above-knee (AK) and 78 BK (including 37 FC) procedures were performed. Follow-up evaluations consisted of clinical examinations, ultrasonographic studies, and distal pulse assessments. Patency and limb salvage rates were assessed by using life-table analyses. RESULTS: The overall primary and secondary 2-year patency rates were 73.6% and 86%, respectively. Two-year primary patency rates according to bypass type were 76.2%, 72.6%, and 68.9% for AK FP, BK FP, and FC bypasses, respectively; the corresponding secondary patency rates were 87.5%, 87.8%, and 79.4%. The 2-year limb salvage rate in patients with critical limb ischemia (n=68) was 89.9%. CONCLUSION: Our findings show that CBAS-ePTFE bypass grafts appear to give prolonged patency rates and indicate that the use of this graft may represent a viable alternative for BK bypasses, which have traditionally yielded less than desirable outcomes. A prospective randomized trial is required to provide more definitive information about the graft's patency and limb salvage performance.     

Late results of two hundred seventeen femoropopliteal bypasses to isolated popliteal artery segments

A 10-year-experience of 217 femoropopliteal bypasses to isolated popliteal artery segments in 207 patients is reported. Thirty-three femoropopliteal bypasses (15%) were performed with reversed saphenous vein and 184 (85%) with polytetrafluoroethylene grafts. Operative indications were gangrene in 121 (56%), nonhealing ulceration in 40 (18%), ischemic rest pain in 51 (24%), and claudication in 5 (2%) cases. The 5-year primary graft patency rate of these bypasses was 59% (reversed saphenous vein, 74%; polytetrafluoroethylene, 55%; p less than 0.05), the secondary 5-year graft patency rate was 61% (reversed saphenous vein, 79%; polytetrafluoroethylene, 56%; p less than 0.05), and the 5-year limb salvage rate was 78% (reversed saphenous vein, 78%; polytetrafluoroethylene, 78%). The 30-day operative mortality rate was 10%, and the 5-year patient survival rate was 38%. Eleven patients (5%) required lower extremity amputation because of progressive gangrene or extensive infection despite a patent bypass to an isolated popliteal artery segment. We conclude that femoropopliteal bypasses to isolated popliteal artery segments (1) have acceptable 5-year graft patency and limb salvage rates; (2) should be performed with reversed saphenous vein grafts when possible; (3) may be performed with polytetrafluoroethylene grafts if necessary, with a resulting limb salvage rate equal to that of reversed saphenous vein grafts; and (4) require sequential extension to an infrapopliteal artery in up to 20% of patients. In addition, the presence of an isolated popliteal artery segment is associated with a high operative mortality rate and limited life expectancy because of coronary artery disease.     

Revascularization of popliteal and below-knee arteries with polytetrafluoroethylene

The expanded polytetrafluoroethylene (PTFE) graft (Gore-tex) is the most frequently used synthetic graft when an alternative to autologous saphenous vein is required. Early results have been encouraging. In the present paper we report on 6 years of results from 153 above-knee (AK) femoropopliteal bypass grafts, 74 below-knee (BK) femoropopliteal bypass grafts, and 54 femorotibial/peroneal bypass grafts. The main indication for the vascular reconstruction was severe ischemia. Preventive antibiotics were given to 95% of the patients. Minimum observation time was 1 year after implantation. There was no operative death. Graft infection was seen in less than 5% of patients. The 6-year cumulative limb salvage rate was 87% for patients with severe ischemia in the AK femoropopliteal bypass group, 59% for those in the BK femoropopliteal bypass group, and 57% for those in the femorotibial/peroneal bypass group. The graft patency rate was 88% at 2 years and 78% at 6 years for the AK femoropopliteal bypass group, for whom the operative indication was disabling claudication, and 81% and 68%, respectively, when the indication for the vascular procedure was severe ischemia. The cumulative graft patency rate was 53% and 43% at 2 and 6 years, respectively, after implantation of BK femoropopliteal bypass grafts and 43% and 39% for femorotibial/peroneal bypass procedures. The expanded PTFE (Gore-tex) graft seems therefore to be a good alternative when an autologous vein is not available, even for reconstructions well below the knee joint.     

Cuffed anastomosis for above-knee femoropopliteal bypass with a stretch expanded polytetrafluoroethylene graft

PURPOSE: To evaluate the patency and limb-salvage rates associated with cuffed anastomosis in above-knee femoropopliteal (FP) bypasses using prosthetic grafts. METHODS: Between January 1997 and December 2005, 96 patients (99 limbs) underwent above-knee FP bypass grafting for peripheral vascular disease, with disabling claudication in 81%. All grafts were 6-mm, thin-walled, ringed, expanded polytetrafluoroethylene (ePTFE) stretch grafts anastomosed to the above-knee segment of the popliteal artery in an end-to-side fashion, with a protruding area created around the anastomotic toe and an angle of less than 30 degrees between the graft and the artery. Postoperatively, graft patency was monitored by several objective methods. Patency and limb-salvage rates were calculated by actuarial methods and Kaplan-Meier analysis. RESULTS: The mean follow-up period was 40.4 months; 15 patients were lost to follow-up. The 1-, 3-, and 5-year primary graft patency rates were 94.5%, 88.2%, and 85.7%, respectively. The 1-, 3-, and 5-year secondary patency rates were 95.6%, 94.1%, and 90.8%. The 1-, 3-, and 5-year limb-salvage rates were 98.9%, 97.3%, and 97.3%. There were three graft infections. CONCLUSION: The use of a cuffed anastomosis in FP bypass with an ePTFE stretch prosthesis appears to increase graft patency rates.     

Long-term results with the above-knee popliteal expanded polytetrafluoroethylene graft

Since approximately 30% to 40% of autogenous vein bypass grafts to the femoropopliteal level may occlude within 5 years of implantation, additional vein will be required for subsequent revisions. We undertook a study to determine whether the preferential use of an above-knee expanded polytetrafluoroethylene bypass graft to save vein is an appropriate option. We reviewed our experience with 114 above-knee expanded polytetrafluoroethylene bypass reconstructions. Life-table analysis of primary and secondary graft patency was carried out by the method of Peto and statistically analyzed for the influence of clinical indication, runoff as determined by both preoperative and intraoperative completion arteriography, smoking, and diabetes. The 5-year primary patency rate of 57% for patients with claudication was comparable to contemporary randomized or retrospective series with below-knee autogenous vein for that indication, and it was superior to the patency rate for limb salvage. The status of the runoff vessels was an important determinant of outcome. The 59 limbs with good arteriographic runoff (2 to 3 vessels) had a markedly higher 5-year patency rate (70%) than the poor arteriographic runoff (0 to 1 vessels) group (30%). Continued cigarette smoking and diabetes mellitus also appeared to affect adversely primary graft patency in our hands. Our data support the use of preferential above-knee expanded polytetrafluoroethylene grafts in patients with good angiographic runoff. This approach does not appear to prejudice the limb against secondary revisionary procedures or the use of a new autogenous graft, if required.     

A five-to seven-year experience with externally-supported Dacron prostheses in axillofemoral and femoropopliteal bypass

We have examined the clinical results of 56 externally-supported (EXS) Dacron grafts in the axillofemoral position and 117 in the femoropopliteal position. Results have been analyzed from two perspectives: primary patency concerns only those grafts that had never occluded; extended patency refers to all open grafts including those whose continued patency is the result of thrombectomy. The 5-to 7-year life-table patency rates are: axillofemoral 8 mm and 6 mm bypass: primary 75% and extended 97%; above-knee femoropopliteal 6 mm bypass: primary 78% and extended 93%; below-knee 6 mm femoropopliteal bypass: primary 41% and extended 91%. In contrast, the results for the 5 mm grafts used for femoropopliteal bypass were inferior to the 6 mm grafts: femoropopliteal 5 mm bypasses had an above-knee primary patency rate of 44% and an extended rate of 55%, with a below-knee primary patency rate of 15% and an extended rate of 32%. Rendering the noncrimped porous Dacron prosthesis kink and compression resistant by an external support coil appears to increase its potential for successful use, especially in 8 mm axillofemoral and 6 mm femoropopliteal bypasses. Presented to the Western Vascular Society, January 1986, Laguna Niguel, California.     

Prospective randomized study on bilateral above-knee femoropopliteal revascularization: Polytetrafluoroethylene graft versus reversed saphenous vein

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.     

Early results for below-knee bypasses using Distaflo

In patients who require lower extremity revascularization, prosthetic graft is a reasonable alternative in the absence of a suitable autologous vein conduit. However, prosthetic bypass grafts have limited patency, especially for infrageniculate reconstruction. Polytetrafluoroethylene grafts were geometrically modified at the distal end to increase their patency. The authors reviewed their experience with the Distaflo graft in patients who required lower extremity below-knee popliteal and tibial bypasses when no suitable autologous vein conduit was available. Chart review was conducted of the 57 patients who underwent 60 lower extremity bypasses over a 3-year period between June 2003 and April 2006. Twenty-four revascularizations were constructed to the tibial outflow sites, whereas the remaining grafts were placed to the below-knee (28) and above-knee (8) popliteal artery, respectively. Study endpoints were primary, assisted primary, secondary patency, and limb salvage at the time of follow-up. Distaflo bypass was performed at the infrageniculate level in 86.7% of cases (28 below-knee popliteal, 24 tibial). Mean follow-up time was 12 months (range, 0.5-37.5 months). At 1 year, primary, assisted primary, and secondary patencies and limb salvage rates for below-knee popliteal bypasses were 83.5%, 89.5%, 94.7%, and 94.4%, respectively. Primary, assisted primary, and secondary patencies and limb salvage rates for tibial bypasses were 44.4%, 44.4%, 63.2%, and 74.9%, respectively. Distaflo precuffed graft is a good alternative conduit for below-knee popliteal and tibial lower extremity reconstructions in the absence of an autologous vein and appears to have promising early patency and limb salvage rates even when used for tibial bypasses.     

Femoropopliteal bypass revisited: an analysis of 138 cases

Femoropopliteal bypass is utilized for infrainguinal arterial reconstruction in parents with claudication, rest pain, non-healing ulcers and gangrene. Reported patency and limb salvage rates have varied considerably and controversy exists concerning conduit choice. The purpose of this study was to reveiw the authors' results with femoropoplital bypass to determine factors which may influence outcome in a contemporary series of patients. Between 1986 and 1991, 138 femoropopliteal bypasses were performed in 120 patients. Mean follow-up was 28 (range 1–66) months. Autogenous vein was used in 59% and polytetrafluoroethylene (PTFE) in the remainder. Above-knee anastomoses were performed in 34% and below-knee in 66%. The secondary patency for autogenous vein grafts (95% at 4 years) was significantly better than for PTFE grafts (69% at 4 years; p<0.01). Secondary patency for below-knee autogenous vein grafts also was better than that for below-knee PTFE grafts (95% versus 50% at 4 years; P < 0.02). Limb salavage rates were worse for below-knee PTFE grafts than all other groups (P < 0.01). Eight of 15 failed above-knee PTFE grafts were salvaged with belowknee autogenous vein grafts and did well. In the present series, autogenous vein femoropopliteal grafts demonstrated better overall patency and limb salvage. Below-knee PTFE bypasses should be reserved for limb salvage cases in patients without adequate autogenous conduits. Failed PTFE grafts can be salvaged by autogenous bypasses, yet an advantage to this approach was not seen.     

Dacron vs. polytetrafluoroethylene grafts for femoropopliteal bypass: a prospective randomised multicentre trial.

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.     

A prospective randomized trial comparing vein with polytetrafluoroethylene in above-knee femoropopliteal bypass grafting

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.     

Heparin-bonded Dacron or polytetrafluoroethylene for femoropopliteal bypass grafting: a multicenter trial

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.     

Adjuncts to improve patency of infrainguinal prosthetic bypass grafts

The superiority of autologous venous conduit for infrainguinal arterial bypass has been well documented, especially when the bypass extends below the knee or to the tibial arteries. Nevertheless, when adequate autologous vein is not available, prosthetic bypasses (eg, polytetrafluoroethylene [PTFE] or Dacron) are often used in limb-salvage situations. The inferior long-term patency of these infrainguinal prosthetic bypasses has been documented by a number of studies. One such study reported a prospective multicenter randomized trial with only a 12% primary patency for infrapopliteal prosthetic bypasses after 4 years. Another study reported a similar experience with infragenicular bypasses with PTFE for limb salvage even for above-knee (27%, 5 year) and below-knee (25%, 5 year) femoral-popliteal bypasses. The reported PTFE graft patency was consistently inferior to that achieved with autologous vein for limb salvage. Dacron grafts appear to have similar patency rates to PTFE. In an attempt to improve prosthetic graft patency, a number of surgical and medical adjuncts have been developed. In this review, the authors discuss these adjuncts and their impact on infrainguinal prosthetic graft patency.