Enrico Ascer

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.

Bypasses to plantar arteries and other tibial branches: an extended approach to limb salvage.

During the past 6 years, we have encountered 24 cases in which all major infrapopliteal arteries were occluded as determined by adequate preoperative angiography. Each patient initially had critical ischemia, 14 had a previous failed ipsilateral distal bypass, and seven had an unsuccessful lumbar sympathectomy. Instead of resorting to an amputation, we attempted to perform a bypass using patent branches of distal vessels. Of the 24 bypasses, 14 were to the lateral or medial plantar branches, three were to the deep plantar branch (plantar arch), three were to the lateral tarsal branch, and four were to unnamed branches of the proximal one third of the posterior tibial arteries (two) or anterior tibial arteries (two). All bypasses were performed with reversed saphenous vein with origins at or distal to the superficial femoral artery. Eight bypasses (four plantar and four unnamed branches) became thrombosed up to 30 months postoperatively, resulting in four below-knee amputations. Fifteen bypasses (all plantar branches) have been patent from 6 to 52 months (mean 26 +/- 13 months). The remaining patient required a below-knee amputation at 2 months despite a patent graft. These results underscore the value of this extended approach to limb salvage in situations previously believed to be indications for major amputations. Although bypasses to unnamed branches of the proximal tibial arteries did not fare well, those to the plantar branches and lateral tarsal branch resulted in excellent graft patency and limb salvage.

Short vein grafts: A superior option for arterial reconstructions to poor or compromised outflow tracts?

To determine whether vein graft length is a factor that influences infrapopliteal bypass patency, we reviewed 237 consecutive reversed saphenous vein bypasses performed because of critical ischemia during a 5-year period. One hundred seventeen long vein grafts (LVGs) were longer than 40 cm (42 to 92 cm, mean 60.9 +/- 9 cm) and 120 short vein grafts (SVGs) were 40 cm or shorter (6 to 40 cm, mean 24.7 +/- 8 cm). Ninety-three percent of the LVGs originated from or were proximal to the superficial femoral artery (SFA) whereas all of the SVGs originated at or distal to the SFA. The cumulative patency rate for LVGs at 3 years was 45% and for SVGs was 63% (p less than 0.025). In the absence of an intact pedal arch, 3-year patency rates for LVGs (51 cases) and SVGs (78 cases) were 22% and 53%, respectively (p less than 0.01). High intraoperative outflow resistance measurements (greater than 0.7 mm Hg/ml/min) were encountered in 25 cases. Of these, occlusion within 6 months occurred in six of seven cases with LVGs and in only 8 of 18 cases with SVGs (p less than 0.05). Wound complications at vein harvest sites occurred in 17% of LVGs and in only 6% of SVGs (p less than 0.01). Of 16 additional cases in which a proximal patch angioplasty or percutaneous transluminal angioplasty was performed tandem with a short distal vein graft, four occluded (less than 6 months) and 12 remained patent from 3 to 43 months (mean 12.6 months).(ABSTRACT TRUNCATED AT 250 WORDS)

Reoperation for polytetrafluoroethylene bypass failure: The importance of distal outflow site and operative technique in determining outcome

Of 724 bypasses with polytetrafluoroethylene grafts performed for critical ischemia during a 6-year period, 165 (23%) failed and necessitated reoperation for continued limb salvage. Forty-three failures occurred in 199 femoral-above-knee-popliteal bypasses (F-AKP), 33 failures in 177 femoral-below-knee-popliteal bypasses (F-BKP), 52 failures in 182 femorodistal bypasses (F-D), 28 failures in 85 axillofemoral bypasses (Ax-F), and nine failures in 81 femorofemoral bypasses (F-F). Our reoperative approach consisted of dissection of the distal anastomosis, longitudinal incision in the hood of the graft directly over the anastomosis, and proximal graft thrombectomy. Intimal hyperplasia was treated by patch angioplasty, proximal or distal progression of atherosclerosis was treated by a graft extension, and thrombectomy alone was performed when no cause of graft failure was identified. More recently, a totally new bypass was constructed in 27 cases of F-BKP or F-D failures. Reoperations featuring graft salvage for failed extra-anatomic and F-AKP bypasses yielded 3-year patency rates from the time of first reoperation of 71% and 52%, respectively, whereas for F-BKP and F-D reoperations, 3-year patency rates were 13% and 15%, respectively, at 3 years. However, totally new grafts to a different outflow artery in these settings had 3-year patency rates of 48% and 39%. These data support the aggressive use of reoperation with graft salvage when F-AKP or extra-anatomic graft failure reproduces critical ischemia. Conversely, a new bypass to a virginal outflow site, preferably with autologous vein, should be performed when a polytetrafluoroethylene F-BKP or F-D bypass fails.

Tibiotibial vein bypass grafts: A new operation for limb salvage

Tibiotibial bypasses were performed with short (8 to 33 cm) segments of reversed autologous vein in 14 patients who did not have longer segments of usable vein. All patients faced imminent amputation unless they had an effective revascularization. Two patients died, one within 1 month of operation. One patient required below-knee amputation despite a patent bypass. Eleven patients (79%) have a patent bypass and a functional limb 6 to 50 months after operation. These good patency results even with several grafts inserted into isolated segments of tibial arteries, some with incomplete plantar arches, suggest that these short vein grafts may be superior to other vein grafts. Tibiotibial bypasses may improve limb salvage results in otherwise difficult circumstances.

Cost factors in limb-threatening ischaemia due to infrainguinal arteriosclerosis.

Cost factors are an increasingly important aspect of medical care. In the United States, more than 150,000 patients per year have limb-threatening ischaemia due to infrainguinal atherosclerosis. We studied the economic impact of this disease process and its treatment in 313 consecutive patients seen at our hospital between 1979 and 1981. Minimum follow-up was 3 years. Seventy-nine percent of our patients undergoing revascularisation attempts had limb salvage with full function at 1 year and 60% had full function at 3 years. Of the patients who died, 85% died with their limbs intact. The mean patient cost for all 289 arterial reconstructions was

Components of outflow resistance and their correlation with graft patency in lower extremity arterial reconstructions.

26,194 +/-

Intraoperative outflow resistance as a predictor of late patency of femoropopliteal and infrapopliteal arterial bypasses

876 S.E. (

Influence of vein size (diameter) on infrapopliteal reversed vein graft patency

23,026 +/-

Complementary distal arteriovenous fistula and deep vein interposition : A five-year experience with a new technique to improve infrapopliteal prosthetic bypass patency

1117 for 166 femoropopliteal bypasses;