Polytetrafluoroethylene in above-knee arterial bypass surgery for critical ischemia

Global Vascular Guidelines on the Management of Chronic Limb-Threatening Ischemia

GUIDELINE SUMMARY

Chronic limb-threatening ischemia (CLTI) is associated with mortality, amputation, and impaired quality of life. These Global Vascular Guidelines (GVG) are focused on definition, evaluation, and management of CLTI with the goals of improving evidence-based care and highlighting critical research needs. The term CLTI is preferred over critical limb ischemia, as the latter implies threshold values of impaired perfusion rather than a continuum. CLTI is a clinical syndrome defined by the presence of peripheral artery disease (PAD) in combination with rest pain, gangrene, or a lower limb ulceration >2 weeks duration. Venous, traumatic, embolic, and nonatherosclerotic etiologies are excluded. All patients with suspected CLTI should be referred urgently to a vascular specialist. Accurately staging the severity of limb threat is fundamental, and the Society for Vascular Surgery Threatened Limb Classification system, based on grading of Wounds, Ischemia, and foot Infection (WIfI) is endorsed. Objective hemodynamic testing, including toe pressures as the preferred measure, is required to assess CLTI. Evidence-based revascularization (EBR) hinges on three independent axes: Patient risk, Limb severity, and ANatomic complexity (PLAN). Average-risk and high-risk patients are defined by estimated procedural and 2-year all-cause mortality. The GVG proposes a new Global Anatomic Staging System (GLASS), which involves defining a preferred target artery path (TAP) and then estimating limb-based patency (LBP), resulting in three stages of complexity for intervention. The optimal revascularization strategy is also influenced by the availability of autogenous vein for open bypass surgery. Recommendations for EBR are based on best available data, pending level 1 evidence from ongoing trials. Vein bypass may be preferred for average-risk patients with advanced limb threat and high complexity disease, while those with less complex anatomy, intermediate severity limb threat, or high patient risk may be favored for endovascular intervention. All patients with CLTI should be afforded best medical therapy including the use of antithrombotic, lipid-lowering, antihypertensive, and glycemic control agents, as well as counseling on smoking cessation, diet, exercise, and preventive foot care. Following EBR, long-term limb surveillance is advised. The effectiveness of nonrevascularization therapies (eg, spinal stimulation, pneumatic compression, prostanoids, and hyperbaric oxygen) has not been established. Regenerative medicine approaches (eg, cell, gene therapies) for CLTI should be restricted to rigorously conducted randomizsed clinical trials. The GVG promotes standardization of study designs and end points for clinical trials in CLTI. The importance of multidisciplinary teams and centers of excellence for amputation prevention is stressed as a key health system initiative.

Global vascular guidelines on the management of chronic limb-threatening ischemia

Chronic limb-threatening ischemia (CLTI) is associated with mortality, amputation, and impaired quality of life. These Global Vascular Guidelines (GVG) are focused on definition, evaluation, and management of CLTI with the goals of improving evidence-based care and highlighting critical research needs. The term CLTI is preferred over critical limb ischemia, as the latter implies threshold values of impaired perfusion rather than a continuum. CLTI is a clinical syndrome defined by the presence of peripheral artery disease (PAD) in combination with rest pain, gangrene, or a lower limb ulceration >2 weeks duration. Venous, traumatic, embolic, and nonatherosclerotic etiologies are excluded. All patients with suspected CLTI should be referred urgently to a vascular specialist. Accurately staging the severity of limb threat is fundamental, and the Society for Vascular Surgery Threatened Limb Classification system, based on grading of Wounds, Ischemia, and foot Infection (WIfI) is endorsed. Objective hemodynamic testing, including toe pressures as the preferred measure, is required to assess CLTI. Evidence-based revascularization (EBR) hinges on three independent axes: Patient risk, Limb severity, and ANatomic complexity (PLAN). Average-risk and high-risk patients are defined by estimated procedural and 2-year all-cause mortality. The GVG proposes a new Global Anatomic Staging System (GLASS), which involves defining a preferred target artery path (TAP) and then estimating limb-based patency (LBP), resulting in three stages of complexity for intervention. The optimal revascularization strategy is also influenced by the availability of autogenous vein for open bypass surgery. Recommendations for EBR are based on best available data, pending level 1 evidence from ongoing trials. Vein bypass may be preferred for average-risk patients with advanced limb threat and high complexity disease, while those with less complex anatomy, intermediate severity limb threat, or high patient risk may be favored for endovascular intervention. All patients with CLTI should be afforded best medical therapy including the use of antithrombotic, lipid-lowering, antihypertensive, and glycemic control agents, as well as counseling on smoking cessation, diet, exercise, and preventive foot care. Following EBR, long-term limb surveillance is advised. The effectiveness of nonrevascularization therapies (eg, spinal stimulation, pneumatic compression, prostanoids, and hyperbaric oxygen) has not been established. Regenerative medicine approaches (eg, cell, gene therapies) for CLTI should be restricted to rigorously conducted randomizsed clinical trials. The GVG promotes standardization of study designs and end points for clinical trials in CLTI. The importance of multidisciplinary teams and centers of excellence for amputation prevention is stressed as a key health system initiative.

Vein Versus Prosthetic Graft for Femoropopliteal Bypass Above the Knee: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Conflicting evidence exists surrounding which conduit material is preferable in above-knee femoropopliteal bypass surgery. We performed a systemic review of electronic information sources to identify randomized controlled trials (RCTs) comparing vein versus prosthetic grafts in above-knee femoropopliteal bypasses. Eight RCTs reporting 1271 grafts (608 saphenous vein and 663 prosthetic) in 1132 patients were included. At 5 years, the vein group had significantly higher primary patency (odds ratio [OR]: 1.73, 95% confidence interval [CI]: 1.17-2.55, P = 0.006), primary assisted patency (OR: 4.02, 95% CI: 2.84-5.70, P < 0.0001), and secondary patency (OR: 1.83, 95% CI: 1.20-2.80, P = 0.005) rates compared with the prosthetic group. The vein group required significantly fewer reinterventions (OR: 0.33, 95% CI: 0.18-0.60, P = 0.0003). There was no significant difference in 30-day mortality (risk difference: −0.01, 95% CI: −0.02 to 0.01, P = 0.34), 30-day morbidity (OR: 1.58, 95% CI: 0.61-4.06, P = 0.35), major amputation (OR: 0.71, 95% CI: 0.43-1.18, P = 0.19), or overall survival (OR: 0.95, 95% CI: 0.70-1.30, P = 0.76) when comparing vein versus prosthetic grafts. Our analysis supports the use of the saphenous vein in above-knee femoropopliteal bypass grafting owing to its superiority in primary, primary assisted, and secondary patency rates and less need for reintervention when compared with prosthetic grafts.

Predictive factors for better bypass patency and limb salvage after prosthetic above-knee bypass reconstruction

BACKGROUND

Peripheral arterial disease (PAD) is one of the most underestimated diseases because of its high prevalence and unfavorable prognosis. Many PAD patients without suitable autologous veins or options for endovascular treatment receive prosthetic above-knee femoropopliteal bypass (PAKB). Until now predictors of prosthetic bypass failure and of increased amputation risk remain indistinct. This study aimed to identify predictive factors associated with better bypass patency and limb salvage to achieve a more favorable outcome after PAKB reconstruction.

METHODS

Pre-, intra-, and postoperative data of 244 PAKB procedures performed at a German university medical center were collected and analyzed using univariate and multivariate methods. To our knowledge this 12-year experience is the largest retrospective study to identify predictors for patency and limb salvage after PAKB reconstruction.

RESULTS

Of the PAD patients 94% (229/244) were followed for an average of 34.9 months. Patient cohorts characteristics were: mean age, 66.1 years, 181 men (74%), claudication (64%), rest pain (16%), ischemic lesions (20%), arterial hypertension (92%), smoking (79%), hyperlipidemia (65%) and type 2 diabetes (43%). Cumulative primary 1- and 3-year graft patency rates were 60.8% and 50.7%, respectively, and cumulative 1- and 3-year limb salvage rates were 89.3% and 86.1%, respectively. One hundred seven bypasses (43.9%) failed, 26 patients (10.7%) required a major and seven patients (2.9%) required a minor amputation. Overall survival rates of PAD patients after 1- and 3-years were 94.4% and 82.9%, respectively. Subjective symptom improvement was found to be the most important prognostic follow-up factor for graft patency and limb salvage. Patients with recurrent symptoms in the follow-up had an increased risk of emerging bypass failure compared with patients with subjective symptom improvement (patency at 1 year: 40.8% vs 100% and at 3 years: 26% vs 100%; P < .001). No patient with subjective improvement in symptoms during follow-up underwent an amputation (limb salvage at 1 year: 100% vs 79% and at 3 years: 100% vs 72.8%; P < .001). Therefore, subjective symptom improvement should be the decisive criterion to determine follow-up intervals of PAD patients. In univariate analysis further significant factors associated with better graft patency and limb salvage rates were: claudication compared with critical ischemia, larger graft diameter (>6 mm), pre- and postoperative antiplatelet therapy, statin therapy independent from lipid values after PAKB revascularization, and an experienced vascular surgeon.

CONCLUSIONS

In our study, we determined the subjective improvement in symptoms as the most important prognostic factor for bypass function and limb salvage after PAKB. Furthermore, disease stage of critical ischemia, graft diameter, preoperative aspirin use, and postoperative statin medication were independent predictive factors. Therefore, PAD patients should be treated with aspirin pre- and postoperatively as well as with a statin postoperatively. In case of PAKB reconstruction only prostheses with a large diameter (>6 mm) should be used and the procedure should be performed by an experienced surgeon. Considering these results with regard to the predictive factors for better graft patency and limb salvage rates a significant more favorable outcome during the follow-up and an increased 5-year patency rate for PAKB reconstructions can be expected.

An Update on Endovascular Therapy of the Lower Extremities

Considerable advances have been made over the last decade in percutaneous technology for treatment of atherosclerotic diseases in the iliac, femoropopliteal, and distal tibioperoneal arteries. While treatment strategies are well defined in the iliofemoral segment, where angioplasty and stenting perform well in appropriately selected lesions, the search for a durable transcatheter therapy for femoropopliteal and distal occlusive disease continues. The spectrum of treatment alternatives to angioplasty ranges from transcatheter plaque excision to laser ablation, rotational atherectomy, cryoplasty, brachytherapy, and stenting. We review in this article the status of percutaneous endovascular techniques for the treatment of lower extremity vascular occlusive disease.

Morbidity of femoropopliteal bypass surgery

A systemic review of published reports on the incidence of early (<30 days) adverse events occurring after above- or below-knee femoropopliteal bypass surgery was conducted to provide contemporary outcomes data for comparative reporting. A total of 38 articles were included describing 6,374 femoropopliteal bypasses in 6,007 patients. Fifty-two percent were male and the mean age was 64.6 years (range, 40 to 93 years). The various studied types of complications were reported in 10 to 34 of 38 articles and definitions were often missing. The overall 30-day morbidity rate was 36.8%. The wound infection rate was 7.8% (range, 0.0 to 17.4%) accompanied with dermal necrosis in 0.4%. Graft infection was described in 2.4% (range, 0.0 to 5.3%) of cases. Postoperative bleeding was seen in 7.4% (range, 0.0 to 26%), of which 2.5% required return to surgery. Occlusions were reported in 12.0% (range, 0.0 to 59%). Lymphedema occurred in 2.9% (range, 0.0 to 9.6%) of cases and surgical site seroma formation occurred in 2.0% (range, 1.0% to 3.0%). Overall 30-day mortality rate was 2.3% (range 0.0 to 4.3%). Pooled data comparing vein grafts and prosthetic grafts revealed no significant difference (P = .10; risk ratio = 0.82; 95% confidence interval, 0.66-1.03; I(2) = 0%) in the incidence of complications. This review confirmed the morbidity of femoropopliteal bypass surgery is inconsistently reported and definitions are lacking. Because one-third of patients can be expected to experience an adverse event after femoropopliteal bypass grafting, standards on defining and reporting complications are necessary if comparative outcome standards are developed.

Basic data related to surgical infrainguinal revascularization procedures: a twenty year update

In 1990, Dalman and Taylor published a compilation of reported data that were identified by them as related to infrainguinal revascularization procedures in peripheral vascular surgery during the decade of the 1980s. The intervening 20 years has seen revolutionary advances in the field of peripheral vascular surgery, especially in the adoption of endovascular techniques, and an explosion of data related to emerging technologies in the field of infrainguinal revascularization. The tables in this manuscript reflect the evolution of our surgical knowledge during the turn of the 21st century. The superior patency of autologous saphenous vein in all positions is reaffirmed.

Femoro-popliteal bypass above knee with saphenous vein vs synthetic graft

There is still debate whether sintethic graft (polytetrafluoroethylene or Dacron) is equivalent to vein as bypass graft material for the above-knee femoropopliteal bypass. Therefore, we performed prospective randomized trial to compare vein with polytetrafluoroethylene/dacron for femoropopliteal bypasses with the distal anastomosis above the knee. Between January 2000 and June 2003, 121 femoropopliteal bypasses were performed. The indications for operation were severe claudication in 96 cases, rest pain in 16 cases, and ulceration in 9 cases. After randomization, 60 reversed saphenous venous bypasses and 61 polytetrafluoroethylene/dacron bypasses were performed. 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, 37% of the patients had died and 7% were lost to follow-up. Only once saphenous vein was necessary for coronary artery bypass grafting. Primary patency rates after 5 years were 76,6% for venous bypass grafts and 59,1% for polytetrafluoroethylene/dacron grafts (p=0,035). Secondary patency rates were 83,3% for vein and 69,2% for polytetrafluoroethylene/dacron bypasses (p = 0,036). In the venous group, 10 bypasses failed, leading to four new bypasses. In the polytetrafluoroethylene group, 22 bypasses failed, leading to 12 reinterventions. After 5 years of follow-up, we conclude 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/dacron is an acceptable alternative if the saphenous vein is not available.

Remote endarterectomy for occlusive iliac and superficial femoral artery disease

Today's patients increasingly desire a low-risk procedure with rapid return to functional status following surgery. Many patients actively seek a minimally invasive option. During the last decade, minimally invasive surgical and radiological procedures emerged from their infancy to become an integral part of the treatment strategy in both peripheral arterial occlusive disease and aneurysmal arterial disease. The trend towards restoration of luminal patency, using the vessel itself as a conduit, can also be termed restorative intervention. As radiological percutaneous transluminal angioplasty has thus far proven unsuccessful in the long term for iliac and femoropopliteal occlusive lesions exceeding 10 cm, a new endovascular surgical procedure has been developed. A modification to the original ringstripper, used in semiclosed endarterectomy, was made to enable the technique of remote endarterectomy.

The American Journal of Surgery

In the last of our quarterly digests for 1992, Dr Hiram Polk has this month selected articles from the July to September issues of The American Journal of Surgery, of which he is Editor. Correspondence should be addressed primarily to Dr Polk, although The British Journal of Surgery would be glad to receive a copy.

An update on endovascular therapy of the lower extremities

Considerable advances have been made over the last decade in percutaneous technology for treatment of atherosclerotic diseases in the iliac, femoropopliteal, and distal tibioperoneal arteries. While treatment strategies are well defined in the iliofemoral segment, where angioplasty and stenting perform well in appropriately selected lesions, the search for a durable transcatheter therapy for femoropopliteal and distal occlusive disease continues. The spectrum of treatment alternatives to angioplasty ranges from transcatheter plaque excision to laser ablation, rotational atherectomy, cryoplasty, brachytherapy, and stenting. We review in this article the status of percutaneous endovascular techniques for the treatment of lower extremity vascular occlusive disease.

Dacron femoral-popliteal bypass grafts in good-risk claudicant patients

PURPOSE

To evaluate prosthetic femoral-popliteal (FP) grafts as bypass conduits in favorable patients with refractory calf claudication.

SETTING

University-affiliated urban teaching hospital.

METHODS

Cohort study of patency of 6-mm Dacron FP grafts used to treat patients with medically refractory calf claudication meeting the following criteria: nonsmoker; above-knee popliteal artery as an appropriate target vessel; > or =2-vessel tibial outflow; and postoperative anticoagulation and antiplatelet therapy. End points included primary and secondary FP graft patency, need for and outcome of subsequent intervention, limb amputation, and survival.

RESULTS

From January 1998 through March 2001, 92 patients underwent 100 Dacron bypass grafts for medically refractory claudication. All underwent serial postoperative graft surveillance using duplex ultrasound. Using the Society for Vascular Surgery/International Society of Cardiovascular Surgery criteria life-table, primary patency was 84%, assisted primary patency was 88%, and secondary patency was 90% at 5 years. Two patients (2%) died during a mean follow-up period of 49 months (range 30 to 68). No limbs required amputation. Among 9 limbs in which Dacron FP bypass failed, 8 underwent subsequent successful autogenous bypass to the popliteal artery.

CONCLUSION

In highly selected subjects with favorable features known to increase the likelihood of prosthetic graft patency, prosthetic FP grafts function well. Such patients undergo a simpler, more straightforward procedure than when autogenous FP bypass is performed. Subsequent success of autogenous FP repeat bypass suggests that previous prosthetic FP bypass does not threaten lower-extremity arterial outflow.

Saphenous Vein Versus PTFE for Above-Knee Femoropopliteal Bypass. A Review of the Literature

The autogenous saphenous vein is considered the best bypass graft material for arterial bypasses below the inguinal ligament. However, a synthetic graft or prosthesis is considered an acceptable alternative, especially when the distal anastomosis is situated above the knee. Some studies even suggest that patency rates for vein and synthetic grafts are comparable, whereas others indicate that a vein graft is superior to a prosthetic graft, even above the knee. To test the hypothesis that both vein grafts and synthetic prostheses are equally beneficial in the above-knee position, we performed a systematic review of available studies comparing the patency of saphenous vein and polytetrafluoroethylene (PTFE) as bypass material. English and German medical literature from 1966 to 2002 was searched using Medline, and 25 articles meeting our inclusion and exclusion criteria were selected. The patency of venous bypasses was superior to that of PTFE bypasses at all time intervals studied. After 2 years, the primary patency rate of venous bypasses was 81% as compared to 67% for PTFE bypasses, and after 5 years it was 69 and 49%, respectively. After 5 years, the secondary patency of PTFE bypasses reached 60%. When only randomized trials were considered, venous bypasses were again superior to PTFE bypasses at all intervals studied. After 2 years, the primary patency rate of venous and PTFE bypasses was 80 and 69%, respectively, and after 5 years it was 74 and 39%, respectively. Since both randomized and retrospective studies comparing venous with PTFE bypasses showed that vein grafts were 'better' than PTFE prostheses, the null hypothesis that there is no difference between the two types of graft material was rejected (p=0.008). We conclude from this systematic review that if a saphenous vein is available, a venous bypass should be chosen at all times, even if patients have an anticipated short life expectancy (<2 years). If the saphenous vein is absent or not suitable for bypass grafting, PTFE is a good alternative as bypass material.

Long-term Outcome of Femoral Above-knee Popliteal Artery Bypass Using Autologous Saphenous Vein Versus Expanded Polytetrafluoroethylene Grafts

Despite a recent flurry of publications on preferred techniques for femoral above-knee popliteal artery bypass, controversy persists over the use of autologous saphenous vein and expanded polytetrafluoroethylene (ePTFE) grafts. The purpose of this study was to compare our long-term results using these two bypass materials. In a series of 474 infrainguinal bypasses performed between January 1993 and December 1998, we performed a total of 75 femoral above-knee popliteal artery bypass using an autologous saphenous vein graft in 48 cases (64%) and an ePTFE graft in 27 cases (36%). Prosthetic grafts were used by choice in 17 cases and by necessity due to the absence of useable vein in 10 cases. There were 55 men and 18 women with a mean age of 70 years. The indication for bypass was lower extremity arterial occlusive disease at stage II in 17 cases (22.7%), stage III in 9 cases (12%), and stage IV in 36 cases (48%); subacute ischemia in 8 cases (10.7%); and femoropopliteal aneurysm in 5 cases (6.7%). Preoperative arteriography demonstrated three patent leg arteries in 15.5% of cases, two patent leg arteries in 43.5%, and one patent leg artery in 41%. There was no significance difference between the vein graft and ePTFE graft groups with regard to indications and arteriographic findings. No patient died during the immediate postoperative period. The mean duration of follow-up was 25.5 months (range, 3 to 108 months). The primary patency rate at 4 years was 82.2 +/- 8% for venous bypass vs. 80.6 +/- 11.8% for ePTFE bypass (p = 0.42). The secondary patency rate at 4 years was 84.7 +/- 7.4% for vein bypasses and 79.5 +/- 12% for ePTFE bypasses (p = 0.26). In our experience, there was no statistically significant difference in long-term outcome of femoral above-knee popliteal artery bypass using autologous vein grafts or prosthetic ePTFE grafts.

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.

A prospective randomized trial comparing vein with polytetrafluoroethylene in above-knee femoropopliteal bypass grafting

OBJECTIVE

Despite many clinical studies, there is still uncertainty as to whether venous material is superior to polytetrafluoroethylene for femoropopliteal reconstruction proximal to the knee joint. Supported by early satisfactory results with thin-walled, stretched polytetrafluoroethylene for suprageniculate bypass grafts, a prospectively randomized clinical trial was designed to evaluate the effectiveness of reversed saphenous vein in comparison with that of polytetrafluoroethylene in above-knee arterial reconstruction.

METHODS

In a 3-year period, 151 above-knee femoropopliteal bypass graft operations were performed in 136 patients (77 male, 59 female). The indication for operation was severe claudication in 120 cases, rest pain in 20 cases, and ulceration in 11 cases. For the bypass graft, a reversed saphenous vein was used in each of 75 cases, and a polytetrafluoroethylene prosthesis was used in each of 76 cases. Preoperative risk factors were diabetes (24%), a history of myocardial infarction (23%), and current status with respect to smoking (74%). There was no hospital mortality; 5% of patients had minor postoperative complications.

RESULTS

After 2 years, the primary patency was 83% for saphenous vein and 67% for polytetrafluoroethylene (P =.065); the secondary patency was 83% for saphenous vein and 77% for polytetrafluoroethylene (P =.298). During a follow-up period of 2 years, we found no statistically significant difference in primary and secondary patency between saphenous vein and polytetrafluoroethylene. We found no predictive factor for occlusion of either bypass graft.

CONCLUSION

The use of polytetrafluoroethylene above the knee is a reasonable alternative in femoropopliteal bypass grafting that is associated with acceptable short-term patency rates.

Long term results of polytetrafluoroethylene in above knee femoropopliteal bypass for critical ischaemia

Ninety-six consecutive above-knee femoropopliteal bypasses, using polytetrafluoroethylene (PTFE) preferentially, were performed for limb-threatening ischaemia. Cumulative primary graft patency was 68 per cent, 49 per cent and 36 per cent and limb salvage 93 per cent, 85 per cent and 75 per cent at 1, 3 and 5 yr respectively. As a result of poor long term survival (51 per cent at 5 yr), and the healing of remedial lesions before graft occlusion, 68 patients (72 per cent) required no further intervention. Eighteen secondary bypasses were undertaken, 12 using ipsilateral saphenous vein. In this group of elderly patients with poor life expectancy, where a limited operation is desirable, the use of PTFE provided excellent limb salvage with low morbidity. Although we can no longer justify our continued use of PTFE in every case of critical ischaemia because of its inferior patency to autogenous vein, we continue to use it preferentially in patients whose lifespan is likely to be short and in cases where a remedial lesion is present.

The performance of femoropopliteal bypasses using polytetrafluoroethylene above the knee versus autogenous vein below the knee

BACKGROUND

Controversy exists as to the choice of conduit for the treatment of superficial femoral artery occlusive disease, particularly when a patent above-knee popliteal artery exists. Some surgeons advocate the preferential use of polytetrafluoroethylene (PTFE), whereas others favor the use of autogenous vein. This report compares our experience with above-knee femoropopliteal bypass with PTFE versus below-knee femoropopliteal bypass with autogenous vein.

METHODS

This study covers a 15-year period extending from 1982 to 1996 during which 1,313 arterial reconstructions were performed for superficial femoral and/or proximal popliteal arterial disease. Four hundred and thirty-eight procedures were performed to the above-knee popliteal artery using PTFE, and 875 procedures were performed to the below-knee popliteal artery using autogenous vein. The indication for surgery was limb salvage in 77% of patients in the PTFE group and 88% of patients in the vein group.

RESULTS

The 1-, 3-, and 5-year cumulative life table primary patency rates for the PTFE group were 74%, 56%, and 50%, respectively. The primary patency rates for the vein bypass group were 83%, 75%, and 67%, respectively (P < 0.01). The 5-year cumulative limb salvage rates were 91% and 95% for the PTFE and vein groups, respectively (P = NS).

CONCLUSIONS

In this series, below-knee femoropopliteal venous reconstructions have superior patency rates compared with above-knee femoropopliteal PTFE reconstructions. Venous reconstruction for femoropopliteal occlusive disease gives the optimal long-term result. Prosthetic reconstruction should be considered for patients with limited venous conduit or decreased life expectancy.

The effect of a surveillance programme on the patency of synthetic infrainguinal bypass grafts

OBJECTIVES

Vein graft surveillance is widely acknowledged to be of benefit in improving graft patency at least in the first year after arterial bypass surgery. The aim of this study was to examine the effect of a surveillance programme on the patency of synthetic infrainguinal bypass grafts.

DESIGN

A prospective study of 69 consecutive prosthetic bypass grafts was undertaken over a 3 year period.

METHODS

Patients were seen at 3 monthly intervals after surgery and underwent measurement of ankle brachial pressure indices and a colour Duplex scan of the graft.

RESULTS

The surveillance programme was able to detect treatable lesions in five grafts and in the run-off vessels of two other grafts prior to occlusion. However 14 grafts failed after the first 30 days, 12 of which were not predicted by the surveillance programme.

CONCLUSIONS

Surveillance appears to be of limited benefit in the maintenance of patency of synthetic infrainguinal bypass grafts.