Late results with biograft in peripheral arterial surgery

A total of 106 vascular reconstructions below the inguinal ligament including axillo-femoral and femoro-femoral bypasses were performed using 137 Dardik's human umbilical veins. The indication for surgery was limb salvage in 29%. The distal anastomosis was done with the popliteal artery above the knee in 53 cases, below the knee in 31, and with a tibial artery in 1. The axillo-femoral bypass was performed in 21 cases, and femoro-femoral bypass in 32. The accumulated graft patency rates of femoro-popliteal bypass at 1 yr./3 yrs./5 yrs. were 93%/75%/75%, those of femoro-femoral bypass were 85%/85%/85%, and those of axillo-femoral bypass were 54%/27%/27%. No special risk factor influencing patency rate was found from this study. In long term period, graft aneurysm was observed in 3 cases. It is concluded that the human umbilical vein is the graft material of choice for femoro-popliteal or femoro-femoral bypass when the saphenous vein is not available, and the careful follow-up is important because of the risk of graft aneurysm.     

Venous homografts in infra-inguinal procedures: an eight years experience.

Autogenous saphenous vein is still the first choice graft material for femoro-distal bypass whenever it is available, but the choice of an alternative is still a challenging problem. Between 1982 and 1989, 100 femoro-distal reconstructions were performed with saphenous vein segment homografts, harvested during varicose vein stripping, they were selected, prepared and stored at 4 degrees C. In 71 cases the distal anastomosis was below the knee. According to the actuarial life table analysis (Kaplan & Meyer) the cumulative graft patency rate after 6 months, 1, 3, 5 and 7 years was 79%, 63%, 46%, 45% and 42% respectively. Twelve cases of aneurysm formation or stenosis requiring reintervention occurred. The patency rate was not influenced by the site of the distal anastomosis, but the condition of the run-off vessels had a significant influence on the early occlusion rate. Varicose vein segments are a readily available source of graft material. The low cost, easy storage and handling of these grafts justify their use in limb salvage procedures.     

Umbilical vein bypass in patients with severe lower limb ischemia: a report of 121 consecutive cases

In 112 patients with severe ischemia of the lower limb and without a suitable saphenous vein, 99 femoropopliteal and 22 femorodistal bypass procedures were performed with the modified human umbilical vein (Biograft, Meadox Medicals Inc., Oakland, N.J.). Seventy-eight percent of the operations were performed for limb salvage. In the remaining 22% the indication was severe disabling claudication. Forty-nine percent of the patients had previously undergone arterial reconstruction of the extremity in question. In 36% the distal anastomosis was to the popliteal artery above the knee, in 46% to the popliteal artery below the knee, and in 18% to one of the crural arteries. It was mandatory to perform an additional proximal reconstruction in 38% of the extremities. The observation time ranged from 6 to 60 months, with a mean of 24 months. Two patients died within the first month. The overall cumulative patency rate calculated by the life table method was 67.7% at 1 year, 61.2% at 2 years, and an unchanged 56.6% at 3 to 5 years. The cumulative patency rate in the limb salvage group was higher (58.6%) than the patency rate of the grafts implanted for claudication (46.5%, not significant). Graft patency decreased the more peripherally the distal anastomosis was situated, but we could demonstrate neither a significant relationship between graft patency and runoff nor any prognostic significance in the peroperatively measured flow values. Limb salvage calculated by the life table method was 86% at 1 year and 75.4% at 5 years. It is concluded that the umbilical vein graft is an acceptable alternative for bypass grafting in patients without a suitable autogenous vein.     

Should polytetrafluoroethylene grafts be used in preference to saphenous vein for femoropopliteal arterial bypass?

Some surgeons have advocated using polytetrafluoroethylene (PTFE) as the graft material of choice for femoropopliteal arterial bypass so that the saphenous vein could be preserved for future cardiovascular surgery. We have examined our results to see if this approach could be justified in our patient population. PTFE was used for 101 femoropopliteal reconstructions in 96 patients (56 male and 40 female). Thirty-eight (40%) complained of debilitating claudication and 58 (60%) had limb-threatening ischaemia. There were 83 primary PTFE femoropopliteal reconstructions and 18 repetitive procedures after failure of an earlier ipsilateral bypass. Twenty-nine of the 101 PTFE grafts were anastomosed distally to the popliteal artery above knee and the remaining 72 below knee. At 5 years, the cumulative patency for all grafts was only 11%. The 4 year cumulative patency was better for claudicants (40%) than for those with threatened limb loss (11%) but two of the 38 claudicants required amputation when their grafts failed. Patency rates were not significantly affected by the site of the distal anastomosis or by a previous failed ipsilateral femoropopliteal bypass. Worthwhile limb salvage was achieved only by frequent re-operation. Our results with PTFE are not good enough to use it in preference to an adequate saphenous vein for femoropopliteal bypass.     

Long-term results of femoro-popliteal/tibial bypasses with special references to re-operation in former femoro-popliteal procedures

Since 1962 a total of 1,361 femoro-popliteal/tibial reconstructions have been performed and followed up. In addition to the saphenous vein, Dacron, PTFE, and umbilical vein grafts were used. The following long-term results were achieved: The saphenous vein grafts have a patency of 73.6% after 10 years and of 52.2% after 17 years. Cumulative patency rate for the PTFE grafts were 76.4% after 39 months with above knee and 62.2% after 2 years with below knee reconstructions. After 12 months 85.7% of the umbilical vein grafts were functioning.     

Use of umbilical vein graft as an arterial substitute.

Seventy reconstructions, 14 to the popliteal artery above the knee, 40 to the popliteal artery below the knee, and 16 to the tibioperoneal arteries were performed with the Dardik umbilical vein graft tanned in glutaraldehyde. Indications for use included absence of or inadequate saphenous veins, or for expediency during emergency or complex procedures. The cumulative patency rate (calculated by the life table method) for the total group was 77% at 18 months. The failures are further analyzed according to the type of procedure, the grade of disease, and the distal runoff vessel. Early failures were attributed primarily to poor runoff and not to intrinsic properties of the graft. Our overall experience with the umbilical vein graft has been good. Further long-term follow-up is necessary.     

A retrospective analysis of infra-inguinal arterial reconstruction: three year patency rates.

Primary infra-inguinal arterial reconstructions were reviewed for primary patency and outcome of thrombosis in 144 patients. Distal anastomoses in these patients were to the popliteal artery and were above the knee in 63, below the knee in 53 and at the tibial level in 28. The treatment used was: polytetrafluoroethylene (PTFE) in 33 cases, PTFE with an interposition vein cuff in 29 cases, autogenous saphenous vein (ASV) in situ in 47 cases, and reversed technique in 26 cases. Life table analysis showed a 59% overall primary patency at 3 years. Patency rates of above knee anastomoses (65%) and below knee (61%) were statistically different from the tibial anastomoses (42%, P = 0.005). In both above and below knee popliteal anastomoses there was a statistically significant difference in the patency of ASV and the PTFE/vein cuff technique (P = 0.0006) but there was no difference between ASV and PTFE. There was no difference in patency rates for the various types of grafts with tibial anastomoses. Data were analysed at 3 years, taking into account the variables of smoking, diabetes or indications for surgery respectively and no difference was found in patency. The number and calibre of the run-off vessels did not influence patency significantly, hence anastomosis to any good quality vessel regardless of run-off is recommended. The poor results with the interposition vein cuff technique are unexplained but this study suggests that the technique should be reserved for anastomoses below the popliteal artery.     

A RETROSPECTIVE ANALYSIS OF INFRA-INGUINAL ARTERIAL RECONSTRUCTION: THREE YEAR PATENCY RATES

Primary infra-inguinal arterial reconstructions were reviewed for primary patency and outcome of thrombosis in 144 patients. Distal anastomoses in these patients were to the popliteal artery and were above the knee in 63, below the knee in 53 and at the tibial level in 28. The treatment used was: polytetrafluoroethylene (PTFE) in 33 cases, PTFE with an interposition vein cuff in 29 cases, autogenous saphenous vein (ASV) in situ in 47 cases, and reversed technique in 26 cases. Life table analysis showed a 59% overall primary patency at 3 years. Patency rates of above knee anastomoses (65%) and below knee (61%) were statistically different from the tibial anastomoses (42%. P = 0.005). In both above and below knee popliteal anastomoses there was a statistically significant difference in the patency of ASV and the PTFE/vein cuff technique (P= 0.0006) but there was no difference between ASV and FTFE. There was no difference in patency rates for the various types of grafts with tibial anastomoses. Data were analysed at 3 years, taking into account the variables of smoking, diabetes or indications for surgery respectively and no difference was found in patency. The number and calibre of the run-off vessels did not influence patency significantly, hence anastomosis to any good quality vessel regardless of run-off is recommended. The poor results with the interposition vein cuff technique are unexplained but this study suggests that the technique should he reserved for anastomoses below the popliteal artery.     

Der kniegelenküberschreitende femoropopliteale Bypass mit der glutaral- dehydfixierten denaturierten menschlichen Nabelschnurvene (Dardik-Biograft) – Erfahrungen mit der modifizierten Prothese

Greater saphenous vein is the preferred graft material for below knee bypass. In the case of absent autologous vein, modified human umbilical vein (HUV) is used less frequently than synthetic grafts. To assess long-term graft patency and degenerative changes, the second generation of modified human umbilical vein graft was chosen for below knee femoropopliteal bypass when autologous vein was not available. Fifty-five below knee femoropopliteal bypasses were performed in 54 patients. In most cases the operation was performed for critical leg ischemia, disabling claudication, or severe acute ischemia. In 25% of patients, previous ipsilateral bypass had been performed. In no case was ipsilateral greater saphenous vein suitable. Early graft thrombosis occurred in 30.9% of patients. In 65%, revision with thrombectomy was successful. Primary (secondary) patency rate was 55.2% (75 .5%) with a limb salvage rate of 88.3% after 48 months. After a maximal follow-up of 57.4 months, duplex scanning could not demonstrate significant aneurysmal graft degeneration. Good graft patency and duplex scan results justify continued use of the second generation of modified human umbilical vein in peripheral bypass surgery when autogenous vein is not suitable.     

Infrainguinal bypass surgery: factors determining late graft patency

The results of 373 infrainguinal bypass grafts, in a single centre, between 1980 and 1988 are reviewed. One hundred and thirty in situ vein (ISV), 47 reversed saphenous vein (RSV), 118 polytetrafluoroethylene (PTFE) and 78 human umbilical vein (HUV) grafts were used. The indications for surgery were disabling claudication in 25 per cent of patients and limb salvage in 75 per cent. In 36 per cent of operations the distal anastomosis was above the knee and in 64 per cent it was below the knee. Overall 5-year patency rates and limb salvage rates respectively were, for ISV (41 and 69 per cent), RSV (62 and 90 per cent), PTFE (31 and 67 per cent) and HUV (29 and 59 per cent). There was no significant difference in patency among these grafts at the above-knee level, but significant differences between vein and prosthetic grafts were evident below the knee (P less than 0.001). Using a proportional hazards model the three factors that consistently correlated with late graft patency were graft type (P less than 0.001), site of distal anastomosis (P less than 0.001) and distal run-off (P less than 0.001). Overall, the results suggest that prosthetic grafts are a suitable alternative to autogenous vein when the distal anastomosis is above the knee, but vein should always be used, if available, below the knee joint.     

Distal femoropopliteal bypass using a composite graft of PTFE and non-reversed saphenous vein

The results of femoropopliteal bypass to the infragenicular popliteal artery, in the absence of suitable saphenous vein have, in the main, been disappointing. We present a new type of composite graft, for use when the distal anastomosis is below the knee, which avoids the potential problems of prosthetic graft alone. The graft consists of a proximal segment of 6 mm expanded PTFE (Gore-Tex; or Impra), anastomosed to transposed non-reversed autologous saphenous vein. Forty-two patients were studied following unilateral, below knee composite femoropopliteal graft surgery for severe claudication or critical ischaemia. Pressure indices were calculated along with intraoperative flow rate, and all patients were followed up at regular intervals to assess graft patency. During the study period three patients died and graft occlusion occurred in a further eight. Analysis of the cumulative patency curve revealed that the majority of occlusions occurred in the first 3 months. The patency at 12 and 18 months was encouraging with values of 84% and 79% respectively. Comparison of pressure indices revealed a significant increase following surgery (P less than 0.001). The postoperative pressure index appeared to predict the grafts likely to occlude and the intraoperative flow rates mirrored a similar trend. Grafts which occluded had a significantly lower pressure index and flow rate (P less than 0.01, P less than 0.002, respectively). Our results suggest that for infragenicular femoropopliteal bypass grafting where full length in-situ vein graft is not possible; a composite graft using PTFE with non-reversed vein is a good alternative.     

"Femoro-distal bypass--a worthwhile procedure?"

Infrapopliteal vascular reconstruction was undertaken in 63 patients with limb threatening ischaemia. Graft materials used were reversed autogenous saphenous vein in 33 patients, umbilical vein in 23 patients, composites of saphenous and umbilical vein in six patients, and a Solcograft in one patient. At the end of the first month 13 grafts were non-functioning, and eight of these patients had an amputation performed. Cumulative 3-year limb salvage and patency rates were 69% and 35%, respectively. Cumulative patency rates of saphenous and umbilical vein grafts were equal, and neither the indication for operation nor the preoperative ankle-arm pressure index correlated to graft failure. In total, twenty-two major amputations were performed, 16 below or through the knee, and six above-knee. The conclusion is that vascular reconstructive surgery for limb threatening distal disease is a valuable procedure.     

Limitations of human umbilical vein grafts

Sixty modified human umbilical vein (HUV) grafts were used for arterial reconstruction in 48 patients between December 1979 and December 1981. Forty-four patients had limb-threatening ischemia (rest pain or tissue loss) and four had disabling claudication. Thirty-four patients had HUV grafting after a primary arterial reconstruction had failed. Fourteen had HUV used for their initial arterial bypass. The distal anastomosis was to the popliteal artery in 27 grafts (5 above and 22 below the knee) and the distal calf arteries in 33 (anterior tibial 10, posterior tibial 9, peroneal 14). The cumulative patency rate, calculated by the modified life-table method, was 34% at 1 year and 18% at 2 years. Fifteen patients required major amputation after graft failure; 13 of these healed below the knee. Preoperative and postoperative ankle/brachial systolic pressure indices and intraoperative blood flow did not correlate with graft failure. These results reflect the limitations of HUV as a graft material in patients with severe ischemia of the lower extremities. The prognostic factors that determined the outcome of arterial reconstruction with HUV in these patients remain to be defined.     

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.     

Glutaraldehyde-stabilized umbilical vein prosthesis for revascularization of the legs. Three year results by life table analysis.

Three hundred sixty-one vascular reconstructions for salvage of the leg were performed from 1975 to 1978 employing glutaraldehyde-stabilized umbilical veins. These included 183 bypasses to the popliteal segment, 108 to either of the tibial arteries and 70 to the peroneal artery. One hundred forty-one (77 per cent) of the popliteal reconstructions were below the knee. Operative mortality rates were 2.7,2.8, and 4.3 per cent for popliteal, tibial, and peroneal reconstructions, respectively. The cumulative patency rates at 36 months for each of the three types of reconstructions were 76.4 (popliteal), 63.4 (tibial), and 39.8 per cent (peroneal). The latter figure was statistically insignificant because of the small number of patients between 24 and 36 months. The cumulative patency rate for peroneal reconstructions at 2 years was 55.7 ± 6.2 per cent. Failures were usually due to inappropriate case selection or progressive disease, particularly in the distal circulation. Two grafts were removed because of wound infection and secondary graft infection. There were no instances of aneurysm formation or myointimal proliferation in the graft. These data support the continued use of the glutaraldehyde-stabilized umbilical vein as a suitable alternative to the autologous saphenous vein. The graft provides a reliable material for reconstruction of the leg that is nonantigenic, mechanically equivalent to normal vascular structures, and biocompatible as determined by physical and chemical modalities. The durability of these grafts is based on the thromboresistance of the flow surface and the cross-links established by aldehyde processing. In appropriately selected cases and with expert surgical technique, long-term graft function with limb salvage can be obtained.     

Our eight-year experience with human umbilical vein grafts

From 1977 through 1984, 58 arterial reconstructions using glutaraldehyde-tanned human umbilical vein (H.U.V.) grafts were carried out: 41 femoropopliteal, 4 composite aortopopliteal (a Dacron graft was inserted proximally), 5 femorotibial, 6 axillofemoral, 1 femorofemoral, and 1 iliofemoral bypass. Autogenous saphenous vein was absent or inadequate in all patients. Limb salvage was the primary indication for surgery (89.7%). Five and 8 years cumulative patency rates were 42.8% and 35.1% respectively for all H.U.V. by-passes and 52.4% and 41.9% respectively for femoropopliteal by-passes. Four out of the 5 femorotibial by-passes failed during the first month following surgery. Two of the 6 axillofemoral and 3 of the 4 composite aortopopliteal by-passes thrombosed within 1 and 3 years after surgery, respectively. Perioperative mortality was 5.1%, while overall mortality was 17.2%. The following conclusions can be drawn from these results: H.U.V. grafts did not achieve cumulative patency rates superior to those reported with autogenous saphenous vein, in limb salvage situations, when the saphenous vein is not available, the H.U.V. graft offers acceptable salvage rates, results from the 8-year follow-up period demonstrate the durability and long-term patency of H.U.V. grafts.     

Present status of reversed vein bypass grafting: five-year results of a modern series

From January 1980 through December 1988, 564 limbs in 434 patients were treated for infrainguinal arterial ischemia. Of these, 516 limbs in 387 patients underwent reversed vein bypass grafting. The remainder were treated by primary amputation (11 limbs, 1.9%) or by prosthetic bypass (37 limbs, 6.4%). The indications for operation were limb salvage in 80% of limbs and claudication in 20%. Adequate ipsilateral greater saphenous vein was available for 285 (55%) grafts, with reversed vein bypass achieved in the other 231 operations by use of distal graft origins (151 grafts), use of alternate vein sources (120 grafts), and splicing of venous segments (81 grafts). Seventy-six grafts (15%) were to the above-knee popliteal artery, 199 grafts (37%) were to the below-knee popliteal artery, and 241 grafts (47%) were to infrapopliteal arteries, 26 of which (11%) were to inframalleolar arteries. The primary and secondary patencies for all grafts at 5 years were 75% and 81%, respectively. Grafts to infrapopliteal arteries had significantly worse primary patency (69%) at 5 years than did grafts to the popliteal artery (77%, above knee; 80%, below knee) and grafts formed of adequate ipsilateral greater saphenous vein had significantly better primary patency (80%) than did grafts performed when this conduit was not available (68%). Secondary patency of all graft categories ranged from 76% to 85%, and there were no significant differences regardless of site of distal anastomosis, source of venous conduit, or site of graft origins. We prefer the use of reversed vein bypass grafting for lower extremity revascularization both because of the excellent patency results and because the technique can be applied to the larger number of patients in our practice who lack intact ipsilateral greater saphenous vein, in contrast to in situ vein bypass procedures.     

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.     

Femoropopliteal in situ saphenous vein bypass: Technical aspects and factors determining patency

The results and the factors influencing long-term patency rates in two technical variations of femoropopliteal «in situ» saphenous vein bypass procedures were evaluated retrospectively. Technique I (n=33) consisted of a limited approach to the saphenous vein, destruction of the valves with a Cartier stripper and no tributary ligation. Technique II (n=55) included complete exposure of the saphenous vein valvular destruction using Hall’s stripper and ligation of all tributaries. Early thrombosis was observed in 21% and 3.6% of cases in techniques I and II, respectively. The frequency of local complications was identical in both techniques (18%). Overall actuarial primary patency at 4 years was 70%. Secondary patency (including patency following reoperations for graft failure) was 88 % overall, 78.5% in technique I and 95% in technique II (p<0.05). The site of the distal anastomosis significantly influenced the four year cumulative patency rate (upper popliteal ?100%, lower popliteal ?93.6%, tibioperoneal vessels ?70.5%, p<0,05), whereas the number of patent leg vessels, the clinical stage of disease and the site of the proximal anastomosis (common femoral or superficial fernoral artery) did not. Results obtained with the in situ saphenous vein bypass using technique II were better than with technique I. Close follow-up and preventive reoperations clearly enhanced patency rates. The site of distal anastomosis significantly affected long-term results.     

By-pass grafting for femoro-popliteal atherosclerosis.

175 by-pass operations were performed for femoro-popliteal atherosclerosis during the period January 1967-April 1975. 154 were femoro-popliteal vein by-pass grafts. The material in addition includes 12 distal tibial arterial by-pass grafts, 6 homologous vein grafts, 2 Sparks prosthesis and 1 dacron graft. In the femoro-popliteal vein by-pass group 51% were operated for rest-pain or distal gangrene, while 49% had intermittent claudication. The 4 year patency rate in the two groups was 54% and 66% resepctively and was more favourable when the distal anastomosis was placed above than below the knee. However, the latter group had more severe ischaemic symptoms and the difference is probably in part due to case selection. The results were also more favourable when the proximal anastomosis was placed on the common femoral artery. The operative mortality was 38%. Vein by-pass to the lower leg arteries had a 2 year patency of only 34%. Semi-closed endarterectomy is preferred to homologous vein, Sparks prosthesis or dacron grafts where no sufficient vein for grafting exists. It is concluded that saphenous vein by-pass is the method of choice in patients where femoro-popliteal reconstruction is indicated.