A comparative evaluation of polytetrafluoroethylene, umbilical vein, and saphenous vein bypass grafts for femoral-popliteal above-knee revascularization: a prospective randomized Department of Veterans Affairs cooperative study

PURPOSE: Currently, the choice of a vascular prosthesis for a femoral-popliteal above-knee arterial bypass graft is left to the surgeon's preference, because the available information on comparative evaluations is inconclusive. The Department of Veterans Affairs (VA) Cooperative Study 141 was established to identify whether improved patency exists with different bypass graft materials for patients with femoral-popliteal above-knee bypass grafts. METHODS: Between June 1983 and June 1988, 752 patients at 20 VA medical centers were randomized to receive either an externally supported polytetrafluoroethylene (PTFE; N = 265), human umbilical vein (HUV; N = 261), or saphenous vein (SV; N = 226) for an above-knee femoral-popliteal bypass graft. The indication for the bypass grafting operation was limb salvage in 67.5% of the patients. Patients were observed every 3 months for the first year and every 6 months thereafter. All patients were instructed to take aspirin (650 mg) daily for the duration of the study.Doppler-derived ankle-brachial indices (ABIs) were determined preoperatively and serially postoperatively. A bypass graft was considered to be patent when the Doppler-derived postoperative ABI remained significantly improved (more than 0.15 units higher than their preoperative value) and additional objective information, such as angiograms or operations, did not contradict these observations. Patency failure also included bypass grafts that were removed because of an infection or aneurysmal degeneration. Patency rates were compared by using the Kaplan-Meier life table analysis. RESULTS: The cumulative assisted primary patency rates were statistically similar among the different conduit types at 2 years (SV, 81%; HUV, 70%; PTFE, 69%). After 5 years, above-knee SV bypass grafts had a significantly (P 相似文献   

Heparin-bonded Dacron or polytetrafluorethylene for femoropopliteal bypass: five-year results of a prospective randomized multicenter clinical trial

OBJECTIVE: Dacron was largely abandoned for femoropopliteal bypass 30 years ago, because better patency rates were achieved with saphenous vein. Despite the range of potential prosthetics, polytetrafluoroethylne (PTFE) clearly predominates in current femoropopliteal practice. We compared heparin-bonded Dacron (HBD) with PTFE in a randomized multicenter clinical trial. METHOD: Over 28 months, 209 patients (179 above-knee disease, 30 below-knee disease) were randomized to receive HBD (n = 106) or PTFE (n = 103) grafts. Aspirin, 300 mg/d, was started before surgery, and was continued if tolerated. RESULTS: At follow-up for a minimum of 5 years (mean, 76 months; range, 60-89 months), 37 patients (17.7%) had died with patent grafts and 121 (58%) grafts were occluded. Primary patency rate, measured with Kaplan-Meier survival analysis, was 46% (95% confidence interval [CI], 35%-57%) at year 5 for HBD, compared with 35% for PTFE (CI, 25%-45%; P < .055). Long-term patency was achieved in only 4 of 78 interventions performed in 55 thrombosed grafts. Secondary patency rate for HBD was 47% (CI, 36%-58%), and for PTFE was 36% (CI, 26%-46%). Risk factors for arterial disease did not significantly influence prosthetic patency. Major limb amputation was necessary in 9 patients with HBD grafts and 20 patients with PTFE grafts (P < .025). Two amputations in the HBD group and 8 amputations in the PTFE group were in patients undergoing bypass surgery to treat claudication only. Limb salvage rate was 86% (CI, 77%-95%) and 74% (CI, 64%-84%), respectively. CONCLUSIONS: Significantly better patency rates were achieved with HBD than with PTFE at 3 years (P < .044), but the difference was no longer statistically significant at 5 years (P < .055). The incidence of major limb amputation, however, was significantly greater (P < .025) in the PTFE group compared with the HBD group at both 3 and 5 years of follow-up.     

Factors influencing results of femoropopliteal bypass operations for lower limb ischemia

An ideal way to assess the effectiveness of femoropopliteal bypass procedures is to standardize patient- and surgeon-related variables by randomization. Through statistical analysis of multiple factors influencing patency, limb loss, death rate and hospital stay, the authors reviewed retrospectively 136 bypass procedures performed over 5 years. Variables that contributed significantly to the results were: preoperative symptoms (p = 0.037), graft material used (p = 0.016), age of the patient (p = 0.007), adequacy of runoff (p = 0.041) and smoking postoperatively (p = 0.013). Autogenous vein grafts were superior to prosthetic grafts, the cumulative patency at 5 years being 67.5% and 38.2% respectively. The authors emphasize that all patients needing vascular surgery should be advised to stop smoking, since in this study postoperative smoking increased the probability of limb loss and adversely affected the cumulative patency rate by interaction with other variables such as preoperative symptoms, graft material and age.     

Polytetrafluoroethylene versus human umbilical vein in above-knee femoropopliteal bypass: six-year results of a randomized clinical trial.

In a prospective, randomized trial 6 mm polytetrafluoroethylene (PTFE) and 6 mm human umbilical vein (HUV) were compared in above-knee femoropopliteal bypass grafting. In claudicants a prosthetic graft was used intentionally, in limb-salvage cases only when autologous vein was insufficient. Ninety-six extremities were randomized (49 PTFE and 47 HUV). Operative indication was disabling claudication in 77 and limb salvage in 19 extremities. The two groups were comparable as to preoperative risk factors and operative and postoperative treatment. Median follow-up was 76 months (range 47 to 91 months), during which 23 patients died of nonrelated causes with functioning grafts. Thirty-eight grafts failed (33 because of occlusion and five for other reasons). At 6 years the primary patency rate was 38.7% in the PTFE group and 71.4% in the HUV group (p < 0.001). Corresponding rates for secondary patency at 6 years were 51.4% and 76.4% (p < 0.005).     

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

BACKGROUND: Dacron (polyester fiber) was largely abandoned for femoropopliteal bypass grafts 30 years ago because saphenous vein achieved better patencies. However, in patients taking aspirin, patency in above-knee femoropopliteal bypass grafts has recently been shown to be equivalent to that with saphenous vein. We compared heparin-bonded Dacron (HBD) and polytetrafluoroethylene (PTFE) in a randomized multicenter trial including below-knee popliteal or tibioperoneal trunk bypass graft where the long saphenous vein was absent or inadequate. METHODS: Over 28 months, 209 patients undergoing femoropopliteal bypass grafts (180 above-knee, 29 below-knee) were randomized to HBD (n = 106) or PTFE (n = 103). Each patient was given aspirin (300 mg/d) before surgery, and this continued unless the patient had intolerance to the aspirin. RESULTS: The mean follow-up was 42 months (range, 28-55). Fifteen (7.1%) patients died with patent grafts, and three (1.4%) infected grafts were removed. Patency (measured with Kaplan-Meier survival analysis) at 1, 2, and 3 years for HBD was 70%, 63%, and 55% compared with 56%, 46%, and 42%, respectively, for PTFE (P =.044). A total of 67 secondary interventions were performed on 48 thrombosed grafts; long-term patency was achieved in only three. Risk factors for arterial disease did not significantly influence patency. Amputations have been performed in 23 patients, six after HBD and 17 after PTFE bypass grafts (P =.015). CONCLUSIONS: HBD achieved better patency than PTFE, which carried a high risk of subsequent amputation.     

Serial angiographic follow-up of grafts one year and five years after coronary artery bypass surgery.

OBJECTIVE: We studied retrospectively the patency of grafts after coronary artery bypass grafting (CABG) using serial angiographies performed one year and five years after surgery. METHODS: One hundred and nine patients who had available coronary angiographies at both one year and five years after CABG were included. Morphologic changes of anastomotic sites and grafts were traced in the same group of patients using the FitzGibbon grading system. RESULTS: The arterial graft patency rate (FitzGibbon grade A+B) was significantly higher than the saphenous vein grafts at both one year (98.0% vs 82.4%, p<0.001) and five years (90.7% vs 80.2%, p=0.006) after surgery, respectively. The arterial graft patency rate was superior to vein grafts in the left anterior descending coronary artery territory at both one year (97.5% vs 82.0%, p=0.001) and five years (90.9% vs 78.0%, p=0.042) postoperatively. Other territories showed similar patency rates between arterial and vein grafts. The vein graft patency rate at five years postoperatively was lowest in the right coronary territory when compared with other territories. When the patency pattern was compared between postoperative years 1 and 5, the proportion of FitzGibbon grade B grafts increased significantly in the vein grafts (3.1% vs 7.5%, p=0.002), while that of arterial grafts remained stable (8.6% vs 7.3%, p=0.774). When the graft patency at postoperative year 5 was compared between patients with recurrent angina and those without, the patients with recurrent angina showed a higher proportion of FitzGibbon grade B grafts (19.2% vs 4.8% in arterial grafts, p=0.023; 20.5% vs 4.8% in vein grafts, p=0.003) and lower grade A grafts (65.4% vs 86.4% in arterial grafts, p=0.019; 43.6% vs 78.2% in vein grafts, p<0.001), and a lower vein graft patency rate (64.1% vs 83.0%, p=0.014). CONCLUSIONS: The arterial graft patency rate was significantly higher than that of saphenous vein grafts, especially in the left anterior descending coronary artery territory, at one year and five years postoperatively. The decreased patency rate of the vein grafts, along with insulin-dependent diabetes mellitus, were associated with angina recurrence.     

PTFE or HUV for femoro-popliteal bypass: a multi-centre trial

Despite wide clinical experience the choice between human umbilical vein (HUV) or polytetrafluoroethylene (PTFE) when the saphenous vein is inadequate remains unclear. In a multi-centre trial of 801 femoro-popliteal bypasses, autogenous vein could not be used in 252 (31%), of which 191 were randomised to either HUV or PTFE and started on aspirin 300 mg plus dipyridamole 150 mg (ASA + DPM) twice daily. Graft patency measured objectively by independent trial coordinators was expressed on an "intention to treat" basis by life table and analysed statistically by log rank and confidence intervals (95% CI). Overall, 101 grafts failed and cumulative patency was 53% (45-61%) at 3 years compared with 60% (55-65%) in 549 vein grafts. Prosthetic bypass patency above knee was 65% (55-75%); markedly better than 35% (23-47%) below knee (p less than 0.001) and comparable with 62% (55-69%) in 217 above knee saphenous vein grafts. Most failures occurred early at a rate of 52/1000 patient-months in the first 3 months (43/1000 for vein) falling to 21/1000 by 6 to 12 months and around 10/1000 subsequently. Randomisation produced comparable groups of 87 HUV and 104 PTFE grafts. Cumulative primary patency for HUV was 68, 63 and 57% at 1, 2 and 3 years, respectively compared with 61, 56 and 48% for PTFE with wide confidence intervals for the difference at 3 years (-20 to 38%, p = 0.27).(ABSTRACT TRUNCATED AT 250 WORDS)     

Femoro-distal bypass surgery at Groote Schuur hospital--4-year retrospective study

An analysis of the demographics and outcome of femoro-distal bypass in patients presenting with defined critical limb ischaemia at Groote Schuur Hospital, Cape Town, is presented. MATERIALS AND METHODS: A retrospective review was conducted between January 1998 and December 2001. During this period, 65 patients underwent femoro-distal bypass. Of these, 57 patients were analysed and 8 patients were excluded from the study because of incomplete medical records RESULTS: The median age of the patients in this study was 62 years, with a male-to-female ratio of 34:23. Twenty-eight patients (49%) were diabetic. An overall 2-year mortality of 19.2% was recorded. Reversed saphenous vein graft (RSVG) was used in 29 legs (50.9%) and in situ vein graft (ISVG) in 19 legs (33.3%). There was no statistically significant difference in the graft patency between the two methods (p = 0.39); the 2-year cumulative patency was 40% for the RSVG and 39% for the ISVG. In our unit only 2 factors influenced the outcome of femoro-distal bypass--local sepsis in the foot and an increased early postoperative ankle-brachial index (p < 0.05). Diabetes mellitus, gender, age and race had no influence on the outcome. This study showed that the site of the distal anastomosis had no effect on graft patency or limb salvage. At 2 years, the cumulative patency and limb salvage rates were 40% and 56% respectively. Of the 11 grafts with stenotic lesions requiring intervention, 6 were detected between 18 and 24 months. CONCLUSION: Management of critical limb ischaemia is a major part of the workload in our unit, with most patients undergoing primary amputation. The surgical outcome of femoro-distal bypass was largely influenced by local sepsis and early postoperative ABI. We found that more than half the stenotic lesions detected during graft surveillance occurred beyond 18 months postoperatively. This suggests that a graft surveillance programme should continue beyond 18 months.     

Infrapopliteal composite bypass with autologous vein and second generation glutaraldehyde stabilized human umbilical vein (HUV) for critical lower limb ischaemia.

OBJECTIVE: To audit a single center consecutive series of infrapopliteal composite bypasses with second generation glutaraldehyde stabilized human umbilical vein. DESIGN: Retrospective study. PATIENTS: From January 1996 to July 2006 89 femoro-distal bypasses were constructed in 85 patients with HUV and residual vein segments as composite grafts in the absence of sufficient length of autologous vein. METHODS: All patients with infrainguinal bypass operations were registered prospectively. Bypasses to infrapopliteal arteries performed with HUV-composite grafts were reviewed for graft patency, limb salvage, patient survival and possible biodegeneration of the HUV. RESULTS: Early graft thrombosis was noted in 21.3%, necessitating revision surgery. Primary, primary assisted and secondary patency rates were 35%, 40% and 42% respectively, with a limb salvage rate of 87% after 5 years. Graft infection occurred in 7 limbs. Aneurysmal HUV graft degeneration was not detected by duplex scanning. CONCLUSION: HUV-composite bypasses provide acceptable patency and favorable limb salvage rates. Patency was similar to previous series using PTFE-composite bypasses but was significantly inferior to vein bypass. Possible biodegradation of the HUV grafts seems to be of minor clinical relevance.     

Popliteal-to-distal bypass: identifying risk factors associated with limb loss and graft failure

Modern therapy, including endoluminal procedures and improved medical management, still yield less than desired results for tibial vessel occlusive disease. Despite the recent focus on these newer interventions, few modern series have evaluated the efficacy of popliteal-to-distal bypass procedures. The authors aimed to determine the efficacy of popliteal-distal bypass and to identify adverse prognostic factors for ultimate limb salvage. Eighty-seven patients (54 men; average age: 63 years) underwent 92 popliteal-distal bypasses. Duplex ultrasound was utilized to assess patency of all grafts. Data were analyzed by life-table analysis to determine patency rates at postoperative intervals. Median patient follow-up was 2.4 years. Major indications for bypass included chronic limb ischemia (86%) and disabling claudication (8%); 62% of the limbs were considered threatened, and 74% of the proximal anastomoses were above-knee. All procedures were technically successful. There were no perioperative (< 30 days) deaths, and 86% of patients were alive at 5 years. Cumulative patency rates were 74% at 6 months, 70% at 2 years, and 63% at 5 years. Limb salvage rates closely paralleled patency rates. At 5 years, 62% of the affected limbs were intact; 72% of the limbs lost were associated with early (< 180 days) bypass failures. Predictors of limb loss included early graft failure (84 days vs 1,288 days, p < 0.0001), younger age (57 years vs 64 years, p = 0.039), history of previous ipsilateral vascular procedures (50% vs 21%, p = 0.03), heavy (> 1 ppd) tobacco use (p = 0.001), and a thrombosed femoral-popliteal bypass at presentation (p = 0.002). When successful, popliteal-distal bypass is associated with excellent long-term patency and limb salvage rates. Early failures are often associated with limb loss. Heavy tobacco use, younger age, early graft failures, repeat revascularization, and presentation with a thrombosed femoral-popliteal graft are associated with limb loss.     

Simultaneous aortic surgery and malnutrition increase morbidity after revascularisation of the mesenteric arteries.

OBJECTIVE: To evaluate the early and late outcome of mesenteric revascularisation in patients who had had elective mesenteric revascularisation for chronic intestinal ischaemia. DESIGN: Retrospective review. SETTING: Academic clinic, United States. SUBJECT: 19 consecutive patients (7 men, 12 women; mean age 70 years, range 53-83). RESULTS: Angiography showed that 2 mesenteric vessels were affected in 7 patients and 3 in 12. Four patients had coexisting symptomatic aortoiliac occlusive disease and 1 patient had bilateral renal artery stenosis. A total of 36 visceral arteries were revascularised. One patient died postoperatively, and 8 developed serious complications. Morbidity and mortality were significantly higher in patients who had simultaneous infrarenal aortic or renal artery reconstructions (p = 0.01). Patients whose body weight before operation was less than 90% of ideal had more complications (8/11) than patients who were within 10% of their ideal body weight (1/8) (p = 0.02). Cumulative survival was 89% at 1 year, 72% at 3 years, and 57% at 5 years. The cumulative graft patency rate was 92% at 3 years and 66% at 5 years. CONCLUSIONS: Mesenteric bypass procedures for chronic mesenteric ischaemia are durable. Long-term survival and graft patency rates are excellent even in older patients. Simultaneous aortic surgery should be avoided because of the associated morbidity. More than 10% below ideal body weight was associated with higher morbidity. For these patients, early total parenteral nutrition postoperatively, or a period of total parenteral nutrition preoperatively may reduce postoperative morbidity and mortality.     

Axillopopliteal bypass grafting: indications, late results, and determinants of long-term patency

In the last 12 years we have performed 55 axillopopliteal bypass graftings with 6 mm polytetrafluoroethylene grafts for limb salvage in 50 patients who were at high risk for limb loss. Indications for this procedure were (1) severe atherosclerotic disease of the common, superficial, and deep femoral arteries (33 cases); (2) failed aortofemoral bypass grafting with sufficient fibrosis or disease progression in the deep femoral artery (five cases); (3) insufficient hemodynamic and clinical improvement after axillofemoral bypass grafting (10 cases); and (4) sepsis in the groin from a previously infected graft (seven cases). The 30-day operative mortality rate was 8%, and the 5-year cumulative patient survival rate was 40%. Overall 1-, 3-, and 5-year cumulative primary graft patency rates were 58%, 45%, and 40%, respectively. Comparable limb salvage rates were 83%, 68%, and 58%. Repeat operations increased 5-year patency rates from 40% to 59% (p less than 0.05). Three-year patency rate for grafts placed in the presence of poor angiographic runoff in one vessel was 62% and for good angiographic runoff (two to three vessels) it was 57% (NS). Grafts to the above-knee popliteal artery had a patency rate of 67% at 3 years, whereas for grafts that crossed the knee joint it was 51% (NS). Three-year patency rate for 24 straight axillopopliteal grafts was 42%, and for 31 sequential axillofemoral-popliteal grafts it was 74% (p less than 0.05). These results show that axillopopliteal bypass grafting is justified when other standard operations are not possible in patients who are in imminent danger of limb loss, and that every possible effort should be made to use the common or deep femoral artery as part of a sequential axillofemoral-popliteal procedure.     

PTFE-vein composite grafts for critical limb ischaemia: a valuable alternative to all-autogenous infrageniculate reconstructions.

OBJECTIVES: to analyse the long-term results of primary composite bypass grafts comparing them to PTFE and vein grafts. DESIGN: a retrospective observational study. MATERIALS AND METHODS: between 1980 and 1996, 568 primary infrageniculate bypass procedures were performed; a saphenous-vein graft was used in 428 procedures, a PTFE graft in 44 and a composite PTFE-saphenous-vein graft in 96. Thirty-six composite grafts were below the knee and the remaining 60 extended more distally. Twenty-one bypass grafts from the latter group were sequential. Mean follow-up was 45.6 months. Five-year primary and secondary patency and limb salvage rates were compared by life-table analysis. RESULTS: cumulative 5-year primary patency for composite grafts was 58% and for saphenous-vein grafts 74%, while secondary patency rate was 75% and 82%, respectively (p <0.05). The 5-year limb salvage rate was 80% for composite grafts and 88% for saphenous-vein grafts (p >0.05). The primary and secondary patency and limb salvage rate for PTFE grafts was 24%, 31% and 40%, respectively. CONCLUSION: Composite grafts of PTFE and saphenous vein are significantly superior to PTFE graft alone and should be used in patients who lack sufficient length of saphenous vein.     

Factors affecting the outcome of 463 femorotibial reconstructions

Between 1973 and 1986, 463 infrapopliteal bypasses were performed on 408 limbs in 383 patients at Royal Prince Alfred Hospital. There were 265 males and 118 females. Their mean age was 69 years, 30% were diabetic, 71% smoked and 38% were hypertensive. The indication for surgery was threatened limb loss in 350 limbs and short distance claudication in 58 limbs. The peri-operative mortality rate was 5%. Cumulative graft patency was 58% (s.e.m. = 2.7) at 5 years. The limb salvage rate was 66% (s.e.m. = 2.5) at 5 years. Cumulative patency rate for autogenous grafts (n = 332) was 63% (s.e.m. = 3.2) at 5 years compared with the cumulative patency rate for synthetic grafts (n = 131) of only 38% (s.e.m. = 5) at 5 years (P less than 0.05). There was no significant difference between the cumulative patency of autogenous grafts originating from the common femoral artery (n = 195) and those from the superficial femoral artery (n = 111). Cumulative patency of autogenous grafts did not significantly differ with the site of distal anastomosis; posterior tibial (n = 79), anterior tibial (n = 98), peroneal artery (n = 138) with 5-year cumulative patency rates of 65% (s.e.m. = 6.4), 65% (s.e.m. = 6.1) and 70% (s.e.m. = 4.6) respectively (P greater than 0.05). Autogenous graft material is the most important determinant of a durable result from femorotibial bypass. Proximal and distal anastomotic sites should be chosen to allow maximal utilization of available autogenous vein.     

Biodegradation of glutaraldehyde-tanned human umbilical vein grafts

A retrospective analysis of the long-term behavior of 111 glutaraldehyde-tanned human umbilical vein (HUV) grafts implanted between September 1977 and December 1993 was conducted. A total of 81 patients, with a mean age of 68.7 years, received the grafts and were followed up for between 1 and 131 months. The 5-year primary cumulative patency rate for above-knee femoropopliteal bypass was 83.1%, whereas that of other bypasses was 60.9%. An aneurysm of the graft was defined as a physically apparent localized dilatation, with diffuse ectasia being excluded. There were 11 aneurysms found in 9 grafts, 2 of which arose at the factory-made suture lines. The accumulated incidence of aneurysms had reached 21.9% by the 6th year. One aneurysm compressed the graft and resulted in limb-threatening ischemia and another resulted in frank rupture. Moreover, reinforcement of the mesh could not prevent aneurysm development, the repair of which is mandatory due to the risk of rupture and acute thrombosis. The HUV grafts showed an acceptable patency rate in the above-knee location, but the incidence of aneurysm formation after 5 years was abnormally high. Thus, both the risks and benefits of HUV grafts must be taken into account when considering their clinical application.     

In situ saphenous vein for lower extremity revascularization.

BACKGROUND. During a 6-year period, 349 in situ saphenous vein bypass grafts were performed for limb salvage by three surgeons. METHODS. Outflow anastomoses were constructed to the infrageniculate popliteal (25%), posterior tibial (20%), peroneal (20%), anterior tibial (19%), and dorsal pedal arteries (7%). Mean patient age was 70 1/2 years. RESULTS. The 30-day mortality rate was 3.2%, and 19% died during the ensuing 68-month interval. At 1, 24, and 60 months primary graft patency was 89%, 77%, and 74%, secondary graft patency was 91%, 80%, and 78%, and cumulative limb survival was 94%, 88%, and 84%, respectively. Cumulative patency rates at 60 months depending on outflow site were as follows: popliteal (85%), anterior tibial (80%), posterior tibial (70%), dorsal pedal (68%), and peroneal (60%). Patency at the peroneal position was significantly inferior to that of other infrapopliteal sites combined (p less than 0.05). Cumulative limb survival at 60 months, according to outflow site, was as follows: popliteal (95%), anterior tibial (85%), posterior tibial (78%), dorsal pedal (73%), and peroneal (67%). There was no significant difference in limb salvage among infrapopliteal outflow sites. However, patency rates and limb salvage were significantly better for the popliteal outflow site than the infrapopliteal outflow sites (p less than 0.01). CONCLUSIONS. (1) A 5-year graft patency rate of 78% and a limb salvage rate of 84% are achievable, (2) peroneal bypass is associated with a lower rate for graft patency but not limb salvage, and (3) popliteal bypass has the best graft patency and limb salvage rates.     

Bypasses to tibial vessels using polytetrafluoroethylene as the solo conduit in a predominantly diabetic population

The authors reviewed the Vascular Surgery Registry at the Beth Israel Deaconess Medical Center between 1990 and 1996 and identified 45 patients (47 limbs) who underwent bypass with polytetrafluoroethylene alone to infra-popliteal vessels. This represented only 2.6% of total tibial bypasses performed during that time. Sixty-nine percent of patients had diabetes. Indication for bypass was limb salvage in 96% of patients. Primary and secondary patency rates at 30 days, 1, 3, and 5 years were 87%, 87%; 58%, 60%; 41%, 43%; and 36%, 39%; respectively. Limb salvage rates at 30 days, 1, 3, and 5 years were 91%, 68%, 63%, and 63%. Cumulative survival rates at 3 and 5 years, however, were 53%, and 42%. The 29 grafts (64%) that were postoperatively anticoagulated with sodium warfarin showed trends in improved primary patency (47% vs 19%, p = 0.07), secondary patency (49% vs 20%, p = 0.03), and limb salvage (67% vs 58%, p = 0.06), at 3 years. There were no significant differences between diabetics and non-diabetics except in a trend toward decreased patient survival at 3 and 5 years in the diabetic population. Postoperatively, there were no deaths but there were two (4.2%) major cardiac complications. These data support the judicious use of tibial vessel bypass using PTFE in selected patients for limb salvage when autologous vein is not available. Diabetic patients appear to have similar results to non-diabetics and the postoperative use of sodium warfarin is beneficial.     

Long‐term prognosis of femoropopliteal bypass: An analysis of 349 consecutive revascularizations

Background : Femoropopliteal bypass is the commonest procedure for lower limb revascularization. The aim of the present study was to determine the long‐term outcomes of femoropopliteal bypass and evaluate the prognostic significance of various clinical factors on the long‐term results. Methods : From 1976 to 1998, 349 consecutive primary femoropopliteal bypass operations were performed on 314 patients at the University of Hong Kong Medical Centre. Indications for operation included claudication (n = 85) and limb‐threatening ischaemia (n = 264). Univariate and multivariate analyses of 14 clinical variables were undertaken to identify significant prognostic factors affecting the graft patency, limb salvage and patient survival rates. Results : The overall primary patency rates of femoropopliteal bypass were 88%, 79% and 76% at 1, 3 and 5 years, respectively. Type of graft material and age of patient were independent prognostic factors of graft patency. The cumulative limb salvage rates were 90%, 86% and 86% at 1, 3 and 5 years, respectively. No clinical factor was found to be predictive of ultimate limb loss. The overall survival rates were 89%, 85% and 78% at 1, 3 and 5 years, respectively. Coronary artery disease was the main cause of late death. Gender and indication for operation were the significant predictive factors of long‐term survival. Conclusions : Femoropopliteal bypass using reversed long saphenous vein provided the most durable long‐term patency. Autologous saphenous vein should be the choice of vascular conduit if available. Male gender and limb‐threatening ischaemia were associated with a poor survival.     

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.     

Infrainguinal Bypass Graft Patency and Limb Salvage Rates in Critical Limb Ischemia: Influence of the Mode of Presentation

Rest pain, ulceration, and gangrene are often considered together in studies describing outcomes in patients with critical limb ischemia. A retrospective analysis of prospectively collected data of 152 infrainguinal bypass grafts performed on 128 patients with chronic critical limb ischemia over a 6-year period was carried out. Grafts were classified according to the mode of presentation and were followed up by regular clinical and duplex examinations. Mean follow-up period was 29 months (range 12 to 60 months). Patients' demographics, risk factors, and graft characteristics were not statistically different between the groups. The 5-year cumulative primary patency rates were 33%, 52%, and 51% for gangrene, ulceration, and rest pain, respectively (p = 0.04). The 5-year cumulative primary assisted patency rates were 46%, 70%, and 72% for gangrene, ulceration, and rest pain, respectively (p = 0.01). The 5-year cumulative secondary patency rates were 48%, 76%, and 75% for gangrene, ulceration, and rest pain, respectively (p = 0.003). The 5-year cumulative limb salvage rates were 59%, 87%, and 83%, for gangrene, ulceration, and rest pain, respectively (p = 0.01). Gangrene is a distinct subcategory of critical limb ischemia with a worse prognosis than ulceration and rest pain and should be classified as such when reporting results of infrainguinal bypass grafts.