Tibial bypass for limb salvage using polytetrafluoroethylene and a distal vein patch

OBJECTIVE: Tibial artery bypass for limb salvage may be required in patients without adequate autogenous vein. The interposition of venous tissue at the distal anastomosis has been advocated to improve the results of prosthetic grafts to tibial arteries. Having reported on technical feasibility and an early experience with polytetrafluoroethylene (PTFE) and a distal vein patch (DVP), we examine the results of this technique with 4-year follow-up. METHODS: From July 1993 to July 1999, 514 tibial bypass grafts were performed, with 80 bypass grafts in 79 patients with PTFE/DVP as the conduit. Patient demographics included 39 men and 40 women (mean age, 67 years); 42 had diabetes mellitus (53%), 16 had renal failure (20%), and 48 had Eagle criteria for increased cardiac risk (60%). Indications for revascularization were rest pain in 39 (49%) and tissue loss in 41 (51%). Lack of adequate vein resulted from previous failed lower extremity bypass graft (47 [59%]), previous coronary bypass graft (21 [26%]), unsuitable vein (8 [10%]), and absent vein due to ligation and stripping (4 [5%]). Follow-up ranged from 1 to 48 months. Results are reported as primary patency or limb salvage +/- SE. RESULTS: Bypass grafts originated from the common femoral artery (40 [50%]), the superficial femoral artery (6 [8%]), and the external iliac artery (34 [43%]). Recipient arteries included anterior tibial (17 [21%]), posterior tibial (28 [35%]), and peroneal (35 [44%]). Four-year primary patency and limb salvage rates were 62.89% +/- 10.6% and 79.21% +/- 8.45%, respectively. There was a 24% mortality rate during the follow-up period. Acute failure occurred in 7 grafts with 5 immediate amputations and 2 revisions. A total of 17 grafts failed during the follow-up period, leading to 11 amputations. CONCLUSION: The DVP technique allows PTFE bypass grafts to tibial arteries with acceptable long-term patency and limb salvage.     

Infragenicular Bypass Graft for Limb Salvage Using Polytetrafluoroethylene and Distal Vein Cuff as the First Alternative in Patients Without Ipsilateral Greater Saphenous Vein

The objectives of this study were to evaluate the results of polytetrafluoroethylene infragenicular bypass grafts with a distal interposition vein cuff in patients with critical limb ischemia in the absence of ipsilateral greater saphenous vein. From January 1997 to June 2002, 58 consecutive below-knee bypass grafts with PTFE and distal interposition vein cuff were performed in 57 patients with a median age of 70.8 years. The distal anastomosis was located at the infragenicular popliteal artery in 18 cases and at tibial vessels in 40. Primary patency, secondary patency, and limb salvage were analyzed using the Kaplan-Meier method. During a median follow-up of 14.4 months (range, 1-50) 26 cases of graft occlusion and 19 major amputations were registered. The primary and secondary patency rates at 12, 24, and 36 months were 57%, 54%, and 47% and 61%, 58%, and 50%, respectively. Limb salvage rates reached 69%, 69%, and 59% at 12, 24, and 36 months. When below-knee revasculanzation is required in patients with limb-threatening ischemia, in the absence ipsilateral greater saphenous vein, PTFE grafts with a distal vein cuff are a reasonable substitute with acceptable long-term patency and limb salvage rates.     

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.     

The multiple sequential distal bypass graft: seven-year follow-up

Thirty-nine infrainguinal bypass grafts with multiple sequential distal anastomoses were performed on 35 patients ranging in age from 32 to 79 years (mean 65.8 years) with severe femoropopliteal occlusive disease. Thirty-eight procedures were performed for limb salvage indications. Distal anastomoses were performed to the popliteal-anterior tibial arteries in seven procedures, the popliteal-posterior tibial arteries in six, the popliteal-peroneal arteries in six, the anterior tibial-peroneal arteries in eight, the posterior tibial-peroneal arteries in 10, and the posterior tibial-anterior tibial arteries in two. Saphenous vein was the graft material in 31 procedures (in situ in two), polytetrafluoroethylene (PTFE) in four, and saphenous vein-PTFE composite in four. The mean Doppler ankle-arm index was 0.38 +/- 0.14 preoperatively and 0.89 +/- 0.13 postoperatively. The early (30-day) graft patency rate was 93%. With life-table analysis, the long-term primary patency rate was 70% at 1 year, 61% at 3 years, and 52% at 7 years for saphenous vein grafts; the secondary patency rate was 65% at 7 years for saphenous vein grafts. The secondary patency rate for PTFE and PTFE-vein composite grafts was 75% at 1 year, 50% at 3 years, and 17% at 5 years. Cumulative life-table limb salvage rates were 91% at 1 year, 85% at 5 years, and 61% at 7 years. The multiple sequential distal bypass graft is durable and highly efficacious in achieving limb salvage.     

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     

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.     

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.     

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.     

Lower extremity revascularization with in situ saphenous vein for critical ischemia

Over a 3 1/2 year period, 55 limbs were revascularized with in situ saphenous vein bypass grafts in 49 patients. Ninety-five percent of grafts were constructed in patients with critical ischemia for limb salvage, and 5 percent were constructed for debilitating claudication. The proximal anastomosis was performed in the groin in all patients. The distal graft was taken to the popliteal artery in 45 percent and to a tibial or isolated popliteal segment in 55 percent, with 55 percent of the grafts having single-vessel runoff. The perioperative mortality rate was 7 percent. The primary immediate patency rate was 91 percent and the secondary immediate patency rate was 98 percent at 1 month. The cumulative patency rate at 42 months was 85.4 percent overall, 86.6 percent for the tibial grafts, and 84 percent for the popliteal grafts. The cumulative limb salvage rate was 100 percent for the popliteal grafts, 90 percent for the tibial grafts, and 94.5 percent overall. All of the patients were followed and 3 required secondary revision. In situ vein bypass is a technically demanding procedure that can be performed successfully in high-risk patients with limbs with minimal runoff and can yield very high long-term patency and limb salvage rates in a community hospital setting.     

Long-term results of infragenicular bypasses with autogenous vein originating from the distal superficial femoral and popliteal arteries

Forty-nine bypasses originating from the distal superficial femoral artery or popliteal artery in 46 patients were reviewed to examine late patency, limb salvage, and factors leading to graft failure. Operations were performed because of tissue loss in 86%, rest pain in 12%, and limiting claudication in 2% of limbs. Proximal anastomosis was from the distal superficial femoral artery in 12% and the popliteal artery in 88%. Distal anastomosis was to the below-knee popliteal artery or proximal tibial vessels in 20% and the distal tibial vessels in 80%. Life-table analysis showed a primary patency rate of 83%, 62%, and 41%, at 1, 3, and 5 years, respectively. The rate of limb salvage at 6 years for all grafts was 69%. Cox proportional hazards analysis determined that stenosis of 20% or greater in the proximal superficial femoral artery before bypass was a significant risk factor for graft failure (p = 0.02) despite the presence of normal intra-arterial pressure at the site of the proximal anastomosis at the time of bypass. Long-term survival in these patients was low, with a 6-year survival rate of only 24%. Infragenicular bypasses originating from the distal superficial femoral artery or the popliteal artery can be performed with patency and limb salvage rates comparable to bypasses originating from the common femoral artery. These bypasses are more likely to fail when performed in the presence of a stenosis 20% or greater in the superficial femoral or popliteal artery proximal to the graft origin.     

Improved patency of infrainguinal polytetrafluoroethylene bypass grafts using a distal Taylor vein patch

OBJECTIVE: The purpose of this study was to evaluate graft patency and limb salvage rates for infrainguinal polytetrafluoroethylene (PTFE) bypass grafts using distal anastomotic Taylor vein patch in patients lacking suitable vein conduit. METHODS: We reviewed 44 patients who underwent infrainguinal bypass between January 1996 and August 2000 using 6-mm PTFE and a distal Taylor vein patch. Postoperative oral anticoagulation was administered to 80% of patients. Graft patency was confirmed during follow-up with serial graft duplex scanning. RESULTS: Operative indications were rest pain, nonhealing ulcer, or gangrene in 76% of patients, 43% of whom had undergone previous ipsilateral leg bypass. Distal anastomotic sites were the below-knee popliteal (29%) and tibial-peroneal arteries (67%). At 1 month, 1 year, and 2 years, respectively, the primary patencies (SE <10%) were 86%, 71%, and 71%; limb salvage rates were 95%, 75%, and 66%; and mortality rates were 5%, 20%, and 20%. CONCLUSIONS: These early results with PTFE and distal Taylor vein patch are promising, and markedly superior to previous reports of PTFE without anastomotic modification. Further long-term follow-up will be necessary to determine the 3- to 5-year durability of such reconstructions.     

Autogenous arterial bypass grafts: durable patency and limb salvage in patients with inframalleolar occlusive disease and end-stage renal disease

OBJECTIVE: The purposes of this study were to determine whether autogenous arterial grafts to distal pedal arteries improve the patency of grafts and limb salvage in patients with end-stage renal disease and nonhealing ischemic wounds and to better define the indications for autogenous arterial grafts. DESIGN: A review of consecutive patients with end-stage renal disease undergoing autogenous arterial grafts from 1994 through 1999 was carried out. The setting was a university hospital. All 11 patients with end-stage renal disease and nonhealing, ischemic wounds (stage IV SVS-ISCVS classification) undergoing autogenous arterial grafting from 1994 to 1999 were evaluated. Noninvasive studies confirmed inadequate perfusion pressures in all patients. Pre-bypass arteriography identified no major arteries patent at the level of the malleolus, with reconstitution of only a distal or branch pedal or plantar vessel less than 1 mm in diameter. Five patients with patent tibial vessels to just above the ankle underwent bypass surgery with autogenous arterial grafts alone. Six patients also had proximal occlusive disease that required grafts longer than the autogenous arterial grafts; in each of these six patients, an autogenous vein graft proximal to the autogenous arterial graft was placed through use of a composite technique. Inflow was from the common femoral artery in one patient, the popliteal artery in five patients, and a tibial artery in five patients. Outflow was to the medial plantar artery in five patients, the distal dorsalis pedis artery in three patients, the lateral plantar artery in two patients, and the superficial arch in one patient. The conduit was the subscapular artery in four patients, the deep inferior epigastric artery in four patients, the superficial inferior epigastric artery in two patients, and the radial artery in one patient. The main outcome measures were assisted primary graft patency and functional limb salvage rate. RESULTS: Follow-up ranged from 6 to 63 months (mean, 20 months); graft patency was determined by means of duplex scanning. All 11 patients are alive, and nine grafts are patent, including three after revision for graft stenosis. Assisted primary patency was 82% at 3 years. All nine patients with patent grafts remained ambulatory and had healed wounds or limited forefoot amputations. CONCLUSION: Autogenous arterial grafts were effective in treating limb-threatening ischemia in patients with end-stage renal disease and inframalleolar arterial insufficiency. Graft patency and limb salvage rates were higher than those reported for autogenous vein graft in these patients. Autogenous arterial grafting may therefore prove to be an effective alternative to autogenous vein grafting in selected patients.     

The merit of polytetrafluoroethylene extensions and interposition grafts to salvage failing infrainguinal vein bypasses

Purpose: The purpose of this study was to evaluate the merit of polytetrafluoroethylene (PTFE) extensions and interpositions for the management of failing infrainguinal vein bypass grafts.Methods: The treatment of 133 failing vein grafts in 125 patients over a 10-year period was retrospectively reviewed. Twenty-two graft-threatening lesions were detected in patients who did not have a usable autogenous vein conduit as determined by preoperative and intraoperative evaluations. A PTFE extension or interposition graft was used for the necessary reconstruction in all cases.Results: Ten lesions were within the vein graft, 11 were proximal to the graft in the femoral or popliteal artery segments, and one was distal to the graft in the popliteal artery. The treatment of these lesions included 19 extensions and three mid graft interpositions. The vein graft lesions developed significantly sooner (mean 10.6 ± 2.5 months) after the bypass ( p < 0.05) than the arterial lesions (mean 28.0 ± 6.1 months). The 3-year cumulative secondary patency rate for these vein grafts treated with PTFE extensions or interpositions was 84% ± 8%. This was not significantly different from the 3-year cumulative secondary patency rate for vein grafts treated with vein extensions or interpositions at our institution over the same time period (82% ± 10%). The 3-year limb salvage rates were 95% and 89%, respectively.Conclusions: These results indicate that PTFE extensions and interpositions can be used successfully to maintain the patency of failing vein grafts and may serve to prolong limb salvage in patients without any usable autogenous vein. Early reintervention with a PTFE conduit in this difficult group of patients is appropriate to salvage a failing vein graft. (J VASC SURG 1996;23:329-35.)     

Infrapopliteal-lower extremity revascularization with prosthetic conduit: a 20-year experience

The use of prosthetic conduits for lower extremity revascularization in the infrapopliteal location remains controversial. The objective of this report is to describe the immediate and long-term results in a series collected over two decades. Of the approximately 1,500 lower extremity revascularizations performed between 1978 and 1998, 81 infrapopliteal bypass cases using polytetrafluoroethylene (PTFE) as conduit in 77 patients were identified. Autogenous conduit was unavailable (86%) due to prior surgery: coronary artery bypass graft (25%), femoro-popliteal bypass (60%), or femoro-distal bypass (23%). All cases were done for critical ischemia using PTFE (6 mm, 95%; ring reinforced, 54%) under general (75%) or regional (25%) anesthesia. The distal anastomosis was to the anterior tibial artery (43%), posterior tibial artery (28%), tibioperoneal trunk (16%), or peroneal artery (12%), and vein patch was used in 25% of cases. Postoperative features included acute graft thrombosis in 11 cases (14%), all done under general anesthesia, perioperative death in 3 (4%), and a mean in-hospital stay of 17 days. Long-term follow-up has ranged from 1 to 144 months (mean, 22 months). At 36 months, primary patency was 20%, secondary patency 42%, and limb salvage 55% calculated by the Kaplan-Meier method. Univariate analyses revealed regional anesthesia was associated with prolonged primary patency (35% vs 15%, p=0.026) while the use of ring-reinforced PTFE conduit was associated with prolonged limb salvage (65% vs 40%, p=0.042). All other variables including gender, smoking, diabetes mellitus, renal failure, decade of operation, use of vein patch or postoperative warfarin were not significantly associated with either prolonged patency or limb salvage. Despite poor primary patency, distal prosthetic bypass can lead to long-term limb salvage. These data suggest distal anastomotic vein patches and postoperative anticoagulation may not be beneficial adjuncts. However, the use of regional anesthesia may decrease the incidence of perioperative thrombosis and the use of ring reinforced conduit may prolong limb salvage.     

Early experience utilizing the in situ saphenous vein technique in 54 patients

We have compared our early and late experience utilizing in situ saphenous vein bypass graft for lower extremity arterial occlusive disease in 54 patients who underwent in situ femoral to popliteal and distal bypass grafts between July of 1983 and February 1985. There were 3 femoral to above-knee popliteal bypasses, 27 femoral to below-knee popliteal bypass grafts, 12 femoral to anterior tibial dorsalis pedis bypass grafts, 10 femoral to posterior tibial bypass grafts and 2 femoral to peroneal in situ bypass grafts. The operative indications were progressive disabling claudication in 8 (15%) and limb salvage in 46 (85%). Eighty-nine percent of the limb salvage patients had 0-1 vessel runoff by arteriogram. Cumulative life table patency of the 54 in situ bypass grafts was 79% at 20 months. One hundred percent of the patients who were operated on for disabling claudication had patent grafts at 20 months. Seventy-eight percent of the limb salvage patients had patent grafts. Fourteen of the limb salvage patients required amputation and of these 14, 10 had patent grafts at the time of amputation. There were 8 deaths in the series. Our results demonstrate that a definite learning curve exists with this technique, however, once established, long-term patency and improved limb salvage statistics can be obtained.     

Effect of Warfarin Anticoagulation on Below-Knee Polytetrafluoroethylene Graft Patency

When polytrafluoroethylene (PTFE) must be used for below-knee bypass to achieve limb salvage, effective anticoagulation with warfarin may improve graft survival. We analyzed our practice of routinely using oral anticoagulation to improve graft patency rates for PTFE grafts to below-knee popliteal and crural vessels in limb salvage procedures. We reviewed our established vascular database from February 1999 through April 2003 to identify those patients who required below-knee and tibial artery bypass with PTFE for critical limb ischemia. All patients were initiated on warfarin anticoagulation postoperatively, with an international normalized ratio (INR) of 2.0-3.0 considered therapeutic. All patients were discharged in the therapeutic range. Life-table analysis and Kaplan-Meier estimates were used to compare primary patency rates with regard to INR and position of distal anastomosis. Cox proportional hazards analysis was performed to compare the patency rates for grafts with therapeutic versus subtherapeutic anticoagulation while correcting for variability in distal runoff. Between February 1999 and April 2003, 74 patients (mean age, 69.2 years; 58% men) had 77 below-knee PTFE bypasses. Indications for operation included rest pain (43), ischemic ulcer (27), and gangrene (7). Patients presenting with occluded grafts more often had a subtherapeutic INR. Patients with a subtherapeutic INR (1.9) had a median primary graft patency of 6.8 months and those with a therapeutic INR (2.0) had a median primary graft patency of 29.9 months (p = 0.0007). Analysis by Cox proportional hazards model demonstrated a significantly better graft patency rate in patients with a therapeutic INR regardless of outflow vessel. The patency rates of PTFE grafts to infrageniculate vessels may be improved by effective anticoagulation with warfarin. This improved patency rate may also result in improved limb salvage and further support the use of PTFE grafts for critical limb ischemia when autogenous vein is not available. Predictably, the best results are seen with an INR therapeutic range of 2.0 to 3.0.Presented at the Twenty-ninth Annual Meeting of the Peripheral Vascular Surgery Society, Anaheim, CA, June 4-5, 2004.     

Infragenicular polytetrafluoroethylene bypass with distal vein cuffs for limb salvage: a contemporary series

HYPOTHESIS: Infragenicular polytetrafluoroethylene (PTFE)-venous cuff bypass grafting provides acceptable graft patency and limb salvage rates for limb salvage. DESIGN: Retrospective clinical review of a consecutive series. SETTING: Vascular surgical practice during the interval October 1, 2000, to September 1, 2004. PATIENTS: Fifty-one male and 49 female patients whose mean age was 76.9 years were operated on for tissue loss (67%), chronic rest pain (28%), and severe claudication (6%). Fifty-two percent of patients were diabetic and 49% had undergone previous leg bypass surgery. All patients had absent or inadequate greater saphenous vein, and 84 patients had absent or inadequate arm vein. INTERVENTIONS: One hundred five infragenicular PTFE bypasses were performed in these 100 patients. Distal targets were the infragenicular popliteal (40), posterior tibial (35), anterior tibial (16), and peroneal arteries (14). Sixty-eight venous cuffs were constructed from lesser saphenous vein. MAIN OUTCOME MEASURES: Graft patency, limb salvage, and patient survival were analyzed. RESULTS: Twelve early graft failures resulted in 7 leg amputations. The mean +/- SE 3-year primary patency and limb salvage rates were 64.4% +/- 12.8% and 74.4% +/- 11.9%, respectively. Perioperative mortality was 2.9% and 3-year survival was 38%. Graft follow-up ranged from 1 to 47 months with a mean of 13 months using life-table methods. CONCLUSIONS: For patients requiring arterial revascularization for limb salvage, in which autologous venous conduit is unavailable, distal venous cuff-PTFE bypass provides acceptable patency and limb salvage rates when viewed in the context of short life expectancy for these elderly patients.     

复合血管序贯式旁路移植术治疗慢性肢体缺血的临床分析

目的:探讨复合血管序贯式下肢动脉旁路术治疗慢性下肢缺血的效果。方法:回顾性分析3年内采用复合式血管序贯式动脉血管重建的25例慢性下肢缺血患者的临床资料。复合血管由聚四氟乙烯（PTFE）人工血管及自体静脉组合而成。PTFE近心端与股总动脉吻合，远端与孤立腘动脉吻合；自体静脉从PTFE血管远端发出并与小腿的胫或腓动脉吻合。结果:自体静脉远端吻合口止于胫前动脉5例，胫后动脉8例，腓动脉12例。术后1，2，3年累积通畅率分别为78%， 72%， 61%。二期累积通畅率分别为83%，77%，68%。救肢率分别为83%，83%，73%。结论:复合血管序贯旁路术治疗慢性肢体缺血远期通畅率较高，具有较好的救肢效果，是解决自体静脉不足的合理选择。     

The distaflo graft: a valid alternative to interposition vein?

INTRODUCTION: the rationale behind the Distaflo graft is inhibition of myointimal hyperplasia through optimisation of haemodynamic forces at the distal anastomosis. This prospective study reports our early clinical results. METHOD: patients with critical limb ischaemia, but no autologous vein, underwent infrainguinal bypass using Distaflo. Clinical and Duplex assessment provided prospective data from which one year cumulative patency, limb salvage and survival rates were calculated using Kaplan-Meier analysis. Log rank test enabled comparison with an historical control group of Miller cuff grafts. RESULTS: fifty Distaflo were inserted over 29 months into 46 patients, median age 68.5 years, 27 male (59%), of which 27 (54%) were re-do procedures. Proximal anastomoses were to common femoral arteries in 40 cases (80%); distal anastomoses were to popliteal vessels in 20 (40%), and tibial vessels in 30 (60%). The Distaflo graft had patency, limb salvage and survival rates of 39, 50 and 82% respectively compared to 49, 56 and 85% respectively in the control group, with no statistical difference (p = 0.39; 0.65; 0.67 respectively; log rank). CONCLUSION: in this non-randomised study, the Distaflo has similar one year patency, limb salvage and survival rates to the Miller cuff, potentially justifying its use an alternative in distal prosthetic arterial reconstruction for critical limb ischaemia.