Patency of infrainguinal polytetrafluoroethylene bypass grafts with distal interposition vein cuffs

Polytetrafluoroethylene (PTFE) prosthetic bypasses in the lower extremity have poor patency rates, particularly in limb salvage cases. Patency and limb salvage rates of PTFE bypasses supplemented by distal interposition vein cuffs were assessed in patients requiring revascularization for critical limb ischemia, in the absence of a suitable autologous saphenous vein. Between October 1993 and April 1996, 163 patients underwent 185 infrainguinal bypasses. Forty-three limbs in 42 patients (12 women, 30 men; mean age 67 years) did not have a suitable autologous saphenous vein (24%) and had femoropopliteal (20) and infrapopliteal (23) bypasses performed. Patients were examined prospectively at 3-month intervals during the first year and at 6-month intervals thereafter to determine graft patency and limb salvage. Postoperative anticoagulation with warfarin was used in 26 patients. Indications for operation included limb salvage in 41 extremities (21 rest pain/ulceration or gangrene, 20 rest pain alone), and disabling claudication in two. Patients were followed clinically for 2–30 months (mean 10 months). Cumulative 2-year life-table patencies for all grafts, femoropopliteal and infrapopliteal bypasses were 64%, 75% and 62%, respectively. Previous primary patencies at the authors' institution for PTFE bypasses without vein cuffs were 35%, 46% and 12% for the same categories. Cumulative life-table limb salvage for all PTFE/vein cuff bypasses in the present series was 76% compared with 37% in previous PTFE bypasses without vein cuffs. Adjunctive use of distal interposition vein cuffs improves prosthetic graft patency, while producing satisfactory limb salvage. Postoperative anticoagulation did not influence graft patency. PTFE/vein cuff for lower-extremity revascularization shows good 2-year patency and is an acceptable alternate conduit in patients with critical limb ischemia when autologous saphenous vein is absent.     

Infrapopliteal bypass for established gangrene of the forefoot or toes

This study was undertaken to assess factors affecting limb salvage after femorodistal bypass in patients with established gangrene. From January 1977 through June 1983, 361 patients underwent infrapopliteal bypasses; 58 patients (59 limbs) had forefoot and/or toe gangrene. There were 33 men and 25 women (mean age 67.6 years), and 40 patients (69%) were diabetic. A total of 71 femorodistal bypass procedures were performed in these patients: a single bypass in 49, repeat procedure in eight, and multiple bypasses in two patients. Graft material was autogenous saphenous vein in 22 cases, polytetrafluoroethylene (PTFE) in 39 cases, and a composite graft in 10 procedures. After bypass 50 patients underwent limited toe or forefoot amputation with uncomplicated healing. Limb salvage by life-table analysis was 70% at 1 year, 60% at 3 years, and 28% at 5 years. The graft patency at 3 years was 65% for vein grafts and 30% for PTFE grafts. In the entire series the operative mortality rate was 1.7%. Age, sex, hypertension, or diabetes mellitus did not influence the result of surgery. Similarly, failure of a previous femoropopliteal or tibial graft did not reduce the likelihood of limb salvage. Graft patency, however, is prerequisite for limb salvage, and graft patency can be maintained by thrombectomy or repetitive bypass. The present study suggests that limb salvage is possible in as many as two thirds of limbs with established gangrene. Although saphenous vein remains the graft material of choice, its absence should not preclude attempts at limb salvage. Repetitive grafting did not jeopardize patient safety but contributed significantly to extended limb survival.     

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.     

Comparison of expanded PTFE and vein grafts in lower extremity arterial reconstructions

Polytetrafluoroethylene (PTFE) bypasses were used in a series of arterial reconstructions to the popliteal artery (45) and to arteries below that level (11). These were performed in high-risk situations in patients who lacked a suitable saphenous vein. Vein bypasses were performed in a comparable series of high-risk situations in patients having a suitable autologous saphenous vein (45 to the level of the popliteal artery and 11 to an artery below that level). PTFE patency rates at 4-14 months were 43 to 45 (96%) for the femoro-popliteal reconstructions (with a limb salvage rate of 39 to 45 or 87%) and 5 of 11 (45%) for the distal bypasses. Saphenous vein bypass patency rates at 8-14 months were 39 of 45 (87%) for the femoropopliteal reconstructions (with a limb salvage rate of 36 of 45 or 80%) and 5 of 11 (45%) for the distal bypasses. These results justify continued use of PTFE grafts in patients without saphenous veins who require lower extremity arterial reconstructions for limb salvage. The exact place of PTFE grafts in arterial reconstructive surgery of the lower extremity definition based on longer periods of observation.     

Durability of the in situ saphenous vein arterial bypass: a comparison of primary and secondary patency

The use of the saphenous vein in situ is associated with unique problems that decrease primary graft patency (patency uninterrupted by revision). During the past 5 years, we have performed 192 in situ saphenous vein bypasses in 182 patients, including 61 to the popliteal artery, 128 to infrapopliteal arteries, and three to isolated popliteal artery segments. The operative indications were critical limb ischemia in 178 cases (93%), popliteal aneurysm in eight cases (4%), and disabling claudication in six cases (3%). A progressive decline in primary patency occurred after operation. The primary patency rate at 36 months was only 48% for femoropopliteal bypasses and was 58% for femorotibial bypasses. In contrast, the secondary patency rate (patency maintained by thrombectomy, thrombolysis, or revision) at 36 months was 89% and 80% for femoropopliteal and femorotibial bypasses, respectively. The improved secondary patency was due to postoperative surveillance of graft hemodynamics and the success of graft revision. Problems unique to the in situ technique (incomplete valve incision, residual arteriovenous fistula, graft torsion and entrapment) accounted for 58% of early (less than 30 days) graft revisions and 52% of late revisions. The use of Doppler spectral analysis at operation and duplex scanning after operation can locate unsuspected technical errors and identify grafts with low flow at increased risk for failure. The primary patency of the in situ bypass mandates objective assessment of valve incision sites at operation and a protocol of postoperative surveillance to identify grafts that require revision. Early surgical intervention of hemodynamically abnormal but patent in situ bypasses is rewarded by excellent secondary patency.     

Prospective, randomized comparison of ringed and nonringed polytetrafluoroethylene femoropopliteal bypass grafts: a preliminary report

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.     

Value and limitations of secondary femoropopliteal bypasses with polytetrafluoroethylene

Secondary femoropopliteal bypasses with polytetrafluoroethylene (PTFE) grafts are widely regarded to be of questionable value. This has prompted some to abandon all attempts at secondary revascularization with PTFE and others to recommend that primary femoropopliteal bypasses be performed preferentially with PTFE grafts so that vein may be used for secondary procedures. Because we questioned both of these views, we reviewed all femoropopliteal bypasses done at our institution in the past 12 years and identified 73 secondary PTFE femoropopliteal procedures performed after a failed ipsilateral infrainguinal bypass (69 failed femoropopliteal; 4 failed femorodistal). Seventy (96%) secondary bypasses were performed for limb salvage and 3 (4%) for severe disabling claudication. Insertion of grafts to the popliteal artery was above the knee in 26 (36%) and below the knee in 47 (64%). Primary life-table graft patency at 4 years was only 38%. Forty-eight reinterventions in 34 limbs were required to restore or maintain graft patency in thrombosed or failing grafts. For thrombosed grafts, 20 interventions consisted of 9 simple thrombectomies and 11 thrombectomies with additional revision procedures (5 distal or proximal extensions, 6 patch angioplasties). Twenty-eight lesions threatening graft patency were treated by percutaneous transluminal angioplasty in 3, proximal or distal extensions in 20, and patch angioplasty in 5. As a result of these reinterventions, the overall secondary patency rate was 55% at 4 years, and the limb salvage rate was 74% at 4 years. Although aggressive follow-up and reintervention may be required, the use of secondary PTFE conduits in the femoropopliteal position is a viable option in patients undergoing limb salvage procedures who are at high risk.(ABSTRACT TRUNCATED AT 250 WORDS)     

Early experience with popliteal to infrapopliteal bypass for limb salvage

In an attempt to improve graft patency and limb salvage in patients with isolated tibial vessel and/or popliteal-tibial vessel occlusive disease, bypass grafts from the popliteal or distal superficial femoral artery to infrapopliteal arteries were used in patients requiring bypass for limb salvage. During a 2 1/2-year period, 23 patients with patent axial vessels and hemodynamically normal inflow to the level of the knee underwent such bypasses. Cumulative graft patency and limb salvage rates at 31 months were 84% and 70%, respectively. Five of the six patients who required below-knee amputation did so because of progressive gangrene in the presence of a patent bypass. Short bypasses between the popliteal and infrapopliteal arteries can significantly contribute to limb salvage in patients with tibial vessel occlusive disease and may be particularly useful in patients with saphenous veins too short for longer bypasses.     

Polytetrafluoroethylene grafts as the first-choice arterial substitute in femoropopliteal revascularization

We studied a series of femoropopliteal bypass operations in which polytetrafluoroethylene (PTFE) grafts were used as the first choice, regardless of the availability of saphenous vein. From Jan 1, 1979 to Dec 31, 1982, 63 PTFE femoropopliteal bypass grafts were placed in 55 patients without exploration of the saphenous vein. Forty-three grafts were placed for limb salvage, and 20 grafts were placed for disabling claudication. Patients were followed up for nine to 53 months (average, 23 months). The operative mortality was 1.8%. There were no infections. The overall patency at 30 months was 76.1%. The 30 months' cumulative patency rate for patients with claudication was 89.3%, and there were no amputations. The cumulative 30-month patency for limb salvage was 70.1%, and there was a limb salvage rate of 81.2%. Because the 30-month results were comparable with reported series using autogenous saphenous vein, we concluded that PTFE conduits may be considered the first-choice arterial substitute for femoropopliteal reconstruction. Until longer follow-ups are available, reversed autogenous saphenous vein should probably be the graft of first choice in younger patients (less than 60 years of age) without coronary artery disease who are undergoing femoropopliteal revascularizations.     

Tibial Bypass Using Complex Autologous Conduit: Patency and Limb Salvage

Over an 8-year period, we performed 93 lower extremity bypasses using complex autologous conduits, which included (1) contralateral greater saphenous vein (GSV), (2) composite GSV, (3) superficial femoral vein, (4) lesser saphenous vein, (5) cephalic or basilic veins, and (6) composite-sequential (PTFE and vein) grafts. These grafts represented 16% of all infrainguinal bypasses during this period, and all grafts were performed to treat limb-threatening ischemia. Survival, patency, and limb salvage were examined by the life-table method. Primary graft patency was 46 and 38% at 3 and 5 years. Assisted-primary patency was 62 and 59%, and secondary graft patency rates were 68 and 64% at 3 and 5 years. Twenty-nine bypasses (31%) required revision to restore or maintain patency. The 3-year limb salvage rate was significantly better when revision was performed for graft stenosis than for graft thrombosis (90% vs. 46%, p < 0.05). Overall limb salvage rate was 73% at 5 years. The mortality rate was 5.4% and the 5-year survival was 51%. Complex autologous tibial bypasses provided acceptable long-term limb salvage in patients with severe ischemia and inadequate ipsilateral GSV. The increased operating time and complexity required did not produce prohibitive operative risks. Postoperative graft surveillance in these complex vein bypasses allowed revision in many cases before graft occlusion occurred and significantly improved long-term limb salvage.     

Femoral-distal bypass with in situ greater saphenous vein. Long-term results using the Mills valvulotome.

During a 7-year period, 440 consecutive in situ saphenous vein grafts originating in the groin were performed in 371 patients, exposing the entire vein for valvulotomy with a modified Mills valvulotome. critical ischemia was the indication for bypass in 68%, and the distal anastomosis was to an infrapopliteal artery in 46%. Thirty-day operative mortality was 2.0%. Postoperative surveillance identified 18 stenotic grafts (4.1%), which were revised while still patent (primary revised patency); 36 grafts (8.2%) underwent revision after graft occlusion (secondary patency). Five-year life-table analysis showed overall primary revised patency of 78%, secondary patency of 83%, limb salvage of 88%, and patient survival of 66%. Femoroperoneal and inframalleolar bypasses fared well. The presence of diabetes did not diminish late graft patency. In contrast to reversed vein grafts, long infrapopliteal in situ grafts had long-term secondary patency similar to shorter femoropopliteal bypass grafts (p greater than 0.05). These results, coupled with the versatility and simplicity of the technique as used in the present series, suggest that in situ vein grafting is the procedure of choice for long infrapopliteal bypass.     

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.     

Results of bypasses to the anterior tibial artery through the interosseous membrane

The purpose of the present study was to retrospectively evaluate the results of anatomically tunneled grafts to the anterior tibial artery for distal revascularization in terms of patency and limb salvage rates as well as local morbidity, which can lengthen the postoperative hospital stay. Twenty-three patients received 24 bypasses to the anterior tibial artery, with grafts tunneled through the interosseous membrane. The mean age was 67 years; 10 patients were diabetic, 12 were smokers, 9 presented with significant coronary artery disease, and 2 with chronic renal insufficiency. The donor vessel was the common femoral artery in 17 cases, the superficial femoral artery in 4, and the infra-articular popliteal artery in 3. The graft material consisted in the reversed saphenous vein in 4 cases, the non-reversed devalvulated ex situ saphenous vein in 11, composite polytetrafluoroethylene (PTFE) + inversed saphenous vein in 6, and PTFE alone in 3 cases. No postoperative mortality was observed, nor was there postoperative graft occlusion or need for major amputation. The average postoperative length of stay in the hospital was 9.7 days. Two local surgical wound complications were observed, which did not necessitate a postoperative hospital stay exceeding 15 days. Cumulative primary patency and limb salvage rates at 3 years were 50% and 70%, respectively. Anatomic tunneling of grafts to the anterior tibial artery yields patency and limb salvage rates comparable to those reported in the literature for distal bypasses and, considered overall, an acceptably low local morbidity and short hospital stay. Definitive superiority over externally tunneled grafts, however, is not definitely demonstrated by this study and should be prospectively tested. Received: 9 May 1997     

A comparison of in situ and reversed saphenous vein grafts for infrainguinal reconstruction

Despite the recent popularity of the in situ saphenous vein graft for infrainguinal arterial reconstruction, considerable doubt exists as to whether this approach offers any real advantage over conventional reversed vein grafts. Therefore we have reviewed our experience with 675 infrainguinal vein grafts undertaken during the past 10 years. There have been no substantial modifications in the technique used for 535 reversed vein grafts over the 10-year period. During the past 3 years, 140 in situ vein grafts have been carried out with the Leather valvulotome used to incise the venous valves. Life-table analysis of 449 femoropopliteal reversed saphenous vein grafts demonstrated 1- and 3-year cumulative patency rates of 81% and 73%, respectively, and a 5-year patency rate of 63%. Seventy-five femoropopliteal in situ bypasses demonstrated a patency rate of 85% at both 1- and 3-year intervals. Cumulative patency rates for 86 femoroinfrapopliteal reversed saphenous vein grafts were 64% and 62% at 1 and 3 years, respectively. Comparable patency rates for 65 infrapopliteal in situ saphenous vein grafts remained stable at 87% for 3 years. Fifteen of the in situ bypasses were anastomosed to vessels at the ankle or foot level, whereas none of the reversed bypasses was carried that far distally. This experience with both in situ and reversed techniques on one service by the same surgeons demonstrates a clear superiority of the in situ saphenous vein graft for infrapopliteal reconstruction at the 3-year interval.     

Axillopopliteal bypass for limb salvage.

Forty-one axillopopliteal bypass grafts have been placed in 30 patients for limb salvage in the past 12 years. The mean patient age was 65.6 years; 8 were women; 19 smoked; and six had diabetes. Sixteen grafts were straight axillopopliteal bypass grafts, and 25 were sequential axillopopliteal bypass grafts. Cumulative life-table primary patency rates at 1, 2, and 3 years were 70%, 56%, and 43%, respectively; secondary patency rates were 73%, 57%, and 50%, respectively. Corresponding limb salvage rates were 86%, 69%, and 69%, respectively. Ringed polytetrafluoroethylene (PTFE) graft patency at 3 years was 61% versus 40% for unsupported PTFE grafts (p = 0.35). Ringed PTFE axillofemoral grafts with sequential femoropopliteal saphenous vein grafts had a 3-year patency of 67%. Graft patency was restored in 25% of occluded grafts by thrombectomy and in 80% of occluded grafts by thrombectomy with graft revision (p = 0.21). Cumulative 3-year patient survival was 48%. The 30-day operative mortality rate was 20%; patients operated on for graft infection had a 30-day operative mortality rate of 36%. The data support the use of axillopopliteal bypass for limb salvage when standard revascularization techniques are contraindicated. Long-term patency is enhanced by use of externally supported PTFE and sequential femoropopliteal saphenous vein.     

Long-term evaluation of composite sequential bypass for limb-threatening ischemia.

When sufficient vein for a completely autogenous femorotibial artery bypass is not available, composite sequential grafting by using vein combined with polytetrafluoroethylene material is a surgical option. This study reviews what is currently the largest collection of these grafts and focuses on technical aspects and long-term patency characteristics. During a 7-year period 67 composite sequential bypasses were used to manage rest pain (38), ulcer (18), or gangrene (11) in 62 patients (mean age, 66 years). Fifty-two percent were men, and 51% had diabetes. This method was used as a primary reconstruction in 30, a second bypass in 16, and in 21 it was used after multiple other failed bypasses. Femoral to above-knee popliteal (44) and below-knee popliteal (23) 6 mm polytetrafluoroethylene grafts were placed. Then extensions of greater saphenous (57) or lesser saphenous (10) vein were anastomosed to the anterior tibial (19), posterior tibial (26), or peroneal (22) arteries. Fifty-three percent were maintained on long-term warfarin (Coumadin) anticoagulation, and 33% were maintained on aspirin. No deaths occurred in the perioperative period. Bypass patency was ascertained by a Doppler pressure and waveform analysis, with mean follow-up of patency or to the time of graft failure of 33 months (1 to 91 months). Three-year patient survival was 72%. Cumulative life-table primary patency of 72% (1-year), 64% (2-year), and 48% (3-year) was calculated. Two grafts are functioning 7 years after placement. Limb salvage was 84% at 2 years and 70% at 4 years. At the time of failure, five grafts retained a patent venous bypass segment, which allowed prompt reconstruction of the proximal portion. In a comparison of grafts with early failure and those with long-term patency, the SVS/ISCVS runoff score, vein diameter, tibial artery diameter, and coagulation status were similar. However, patients with the popliteal anastomosis above the knee had 2-year patency of 72% compared with 46% for those with below-knee anastomoses. This technique, when possible, appears preferable to an all prosthetic tibial bypass.     

Polytetrafluoroethylene in above-knee arterial bypass surgery for critical ischemia.

Seventy-one consecutive above-knee polytetrafluoroethylene (PTFE) femoropopliteal arterial bypasses performed between 1981 and 1989 for critical ischemia were followed prospectively to determine graft patency and limb salvage. Cumulative graft patency and limb salvage rates were calculated by life table analysis. Graft patency was 80%, 68%, 55%, 39%, and 39%, and limb salvage 97%, 87%, 84%, 77%, and 77% at 1, 2, 3, 4, and 5 years, respectively. Twenty-nine grafts have occluded with re-emergence of critical ischemia in 14, treated by 5 amputations and 9 reconstructions using autogenous saphenous vein (ASV) in 6 and PTFE in 3. These favorable results are not as good in terms of primary patency as those reported with ASV, but good limb salvage, good early patency, ease of use, and preservation of the saphenous vein for use later have encouraged us toward primary use of PTFE in selected patients. This experience strongly questions the wisdom of an "all autogenous" policy for reconstruction at this level.     

Isolated femoropopliteal bypass graft for limb salvage after failed tibial reconstruction: a viable alternative to amputation

PURPOSE: Femoropopliteal bypass grafting procedures performed to isolated popliteal arteries after failure of a previous tibial reconstruction were studied. The results were compared with those of a study of primary isolated femoropopliteal bypass grafts (IFPBs). METHODS: IFPBs were only constructed if the uninvolved or patent popliteal segment measured at least 7 cm in length and had at least one major collateral supplying the calf. When IFPB was performed for ischemic lesions, these lesions were usually limited to the digits or small portions of the foot. Forty-seven polytetrafluoroethylene grafts and three autogenous reversed saphenous vein grafts were used. RESULTS: Ankle brachial pressure index (ABI) increased after bypass grafting by a mean of 0.46. Three-year primary life table patency and limb-salvage rates for primary IFPBs were 73% and 86%, respectively. All eight IFPBs performed after failed tibial bypass grafts remained patent for 2 to 44 months, with patients having viable, healed feet. CONCLUSION: In the presence of a suitable popliteal artery and limited tissue necrosis, IFPB can have acceptable patency and limb-salvage rates, even when a polytetrafluoroethylene graft is used. Secondary IFPB can be used to achieve limb salvage after failed tibial bypass grafting.     

Composite sequential grafts in severe ischemia: a comparative study

From October 1978 to June 1983, 64 sequential bypass grafts were performed in 59 patients with limb-threatening ischemia. These patients were classified into three study groups as follows: reversed saphenous vein graft alone (12), composite sequential (proximal polytetrafluoroethylene [PTFE] and distal vein) graft (30), and PTFE graft in entirety (22). Graft patency was confirmed in all cases by serial Doppler ankle pressure measurements or by angiography. Cumulative life-table patency rates were then compared over a period of 27 months. The patency rates for composite sequential grafts using a distal short segment of vein were statistically indistinguishable from those for bypasses performed entirely with saphenous vein. These yielded a patency rate of 80% at 1 and 2 years. In contrast, the 1- and 2-year patency rates of the PTFE sequential grafts were 52% and 47%, respectively (p less than 0.05). Composite sequential bypasses using an otherwise inadequate segment of saphenous vein are a sound alternative revascularization procedure, with a patency rate comparable to that of reversed saphenous vein bypasses.