Infrainguinal ePTFE vascular graft with bioactive surface heparin bonding. First clinical results

AIM: The ultimate aim of improved expanded polytetrafluoroethylene (ePTFE) vascular graft design is to achieve patency rates in femoropopliteal bypass grafting comparable with autologous saphenous vein grafts. Enhanced thromboresistance of the ePTFE material by bioactive surface heparin bonding is one conceivable path toward this goal. This retrospective study was performed to collect the first clinical data for a new ePTFE graft with bioactive surface heparin immobilization. METHODS: Between March 2003 and February 2004, 43 femoropopliteal or femorocrural ePTFE vascular prostheses with bioactive end-point immobilized heparin (Gore-Tex Propaten Vascular Graft), using the Car-meda BioActive Surface technology, were implanted in 40 patients. Twelve prostheses were implanted in above-knee and 31 in below-knee position. The indication for bypass grafting was limb-threatening ischemia in 88% of the patients. The mean follow-up was 16.6 months. RESULTS: The primary 1-year patency was 91% for above-knee bypass grafts and 92% for below-knee bypass grafts. The 2-year primary patency rate for above-knee bypass grafts was 68% and 81% for below-knee bypass grafts. Limb salvage was achieved in 98%. The perioperative mortality was 0%, but during follow-up 22% of the patients died with patent bypass grafts. CONCLUSIONS: While conventional ePTFE grafts, particularly in the below-knee position, have shown poor results even in the short-term, the bioactive heparinized ePTFE graft evaluated in this study provides patency rates comparable with autologous vein grafts. Because the influence of luminal heparin bonding is not only limited to thromboresistance but has impact on, amongst other elements, protein adsorption (thereby improving hemocompatibility), a continuous effect for long-term patency could also be expected.     

Heparin-bonded expanded polytetrafluoroethylene vascular graft for femoropopliteal and femorocrural bypass grafting: 1-year results

OBJECTIVE: Several prosthetic materials have been used for femoropopliteal bypass grafting in patients with peripheral vascular disease in whom a venous bypass is not possible. Expanded polytetrafluoroethylene (ePTFE) is the most commonly used, but patency results have not always equaled those achieved with vein, especially in below-knee reconstructions. This study assessed the performance of a new heparin-bonded ePTFE vascular graft that was designed to provide resistance to thrombosis and thereby decrease early graft failures and possibly prolong patency. METHOD: From June 2002 to June 2003, 86 patients (62 men and 24 women; mean age, 70 years; 99 diseased limbs) were enrolled prospectively in a nonrandomized, multicenter study of the heparin-bonded ePTFE graft. Fifty-five above-knee and 44 below-knee (including 21 femorocrural) procedures were performed. Follow-up evaluations consisted of clinical examinations, ultrasonographic studies, and distal pulse assessments. Patency and limb salvage rates were assessed by using life-table analyses. RESULTS: All grafts were patent immediately after implantation. There were no graft infections or episodes of prolonged anastomotic bleeding. During the 1-year follow-up, 10 patients died, 15 grafts occluded, and 5 major amputations were performed. The overall primary and secondary 1-year patency rates were 82% and 97%, respectively. The limb salvage rate in patients with critical limb ischemia (n = 41) was 87%. Primary patency rates according to bypass type were 84%, 81%, and 74% for above-knee femoropopliteal, below-knee femoropopliteal, and femorocrural bypasses, respectively; the corresponding secondary patency rates were 96%, 100%, and 100%. CONCLUSIONS: In this study, the heparin-bonded ePTFE graft provided promising early patency and limb salvage results, with no device-related complications, in patients with occlusive vascular disease. Longer-term and randomized studies are warranted to determine whether this graft provides results superior to those achieved with other prostheses, especially in patients at increased risk of early graft failure, such as those undergoing below-knee bypass and those with poor run-off or advanced vascular disease.     

Results with heparin bonded polytetrafluoroethylene grafts for femorodistal bypasses

AIM: Expanded polytetrafluoroethylene (ePTFE) grafts are commonly used for femoropopliteal (FP) and femorocrural (FC) bypass grafting. Especially in below-knee (BK) reconstructions, patency is often inferior to the outcome in patients eligible for venous bypass grafting. This study assesses whether the Carmeda BioActive Surface (CBAS), which employs covalent end-point linkage to retain heparin on the device surface, as it is used on the Propaten vascular graft successfully, can prolong patency. METHODS: From June 2002 to December 2005, 138 patients (97 men and 41 women; mean age: 73 years) received the CBAS-ePTFE graft for 153 infrainguinal bypass procedures. Seventy-five above-knee (AK) and 78 BK (including 37 FC) procedures were performed. Follow-up evaluations consisted of clinical examinations, ultrasonographic studies, and distal pulse assessments. Patency and limb salvage rates were assessed by using life-table analyses. RESULTS: The overall primary and secondary 2-year patency rates were 73.6% and 86%, respectively. Two-year primary patency rates according to bypass type were 76.2%, 72.6%, and 68.9% for AK FP, BK FP, and FC bypasses, respectively; the corresponding secondary patency rates were 87.5%, 87.8%, and 79.4%. The 2-year limb salvage rate in patients with critical limb ischemia (n=68) was 89.9%. CONCLUSION: Our findings show that CBAS-ePTFE bypass grafts appear to give prolonged patency rates and indicate that the use of this graft may represent a viable alternative for BK bypasses, which have traditionally yielded less than desirable outcomes. A prospective randomized trial is required to provide more definitive information about the graft's patency and limb salvage performance.     

Prospective,randomized evaluation of a cuffed expanded polytetrafluoroethylene graft for hemodialysis vascular access

BACKGROUND: A cuffed expanded polytetrafluoroethylene (ePTFE) hemodialysis graft was developed to address the problem of recurrent stenosis at the graft-vein anastomosis. The purpose of this study was to compare graft patency and blood flow rates of cuffed and noncuffed (standard) ePTFE grafts placed for hemodialysis access. METHODS: Forty-eight patients were prospectively randomized and followed for up to 24 months after placement of a cuffed or standard ePTFE graft for hemodialysis access. Study end points included time to graft failure and blood flow rates on hemodialysis. RESULTS: Risk factors for graft failure were similar in both groups. However, the overall incidence of graft failure was significantly lower in the cuffed ePTFE graft group (P =.039). Graft patency rates in the cuffed versus standard groups were 64% versus 32% at 12 months (P =.037) and 58% versus 21% at 24 months (P =.0213). No cuffed ePTFE graft failed as a result of venous outflow stenosis. Average graft flow rates were similar when first measured 3 months postoperatively (845 mL/min, cuffed vs 715 mL/min, standard; P =.51) but declined more rapidly in the standard group (12 months, 623 vs 253 mL/min [P =.037]; 24 months, 531 vs 121 mL/min [P =.012]). CONCLUSIONS: The cuffed ePTFE graft was associated with increased blood flow rates during hemodialysis and improved graft patency compared with a standard ePTFE graft. Our results suggest a beneficial effect of the cuffed venous geometry for hemodialysis vascular access.     

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.     

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. Presented at the Seventeenth Annual Meeting of the Société de Chirurgie Vasculaire de Langue Française, May 29-31, 2002, Liege, Belgium.     

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.     

Late failure of reversed vein bypass grafts.

Late failure of reversed vein bypass grafts is preceded by the appearance of stenotic lesions, which progress to total occlusion. These lesions appear either as intrinsic graft lesions or as new arteriosclerotic lesions in contiguous arteries. The present study summarizes the University of Pennsylvania experience with these lesions in 521 vein grafts inserted from 1979 to 1985. The grafts were grouped according to the site of the distal anastomosis; 231 above-knee popliteal (FP AK), 171 below-knee popliteal (FP BK), and 119 tibial (FT). The overall incidence of stenotic lesions was essentially identical with the three grafts (21%), but the relative incidence of intrinsic graft to arterial lesions was higher with the more distal grafts. The most common graft lesions developed adjacent to the proximal anastomosis, which is the narrowest part of a reversed vein graft. The popliteal artery was the most common site of outflow stenosis. There was negligible incidence of tibial lesions. The most common inflow arterial lesion was located in the common femoral and iliac arteries. The superficial femoral artery (SFA) was a rare site of inflow stenosis, even though it was at risk because 96 grafts originated from the SFA or popliteal artery. Sixty-seven per cent of the graft and 52% of the arterial lesions were treated successfully by percutaneous transluminal angioplasty; the rest had minor surgical revisions. This resulted in a 19%, 10%, and 9% improvement in 5-year patency for the FT, FP BK, and FP AK bypasses. These results justify an aggressive policy of graft surveillance to identify and treat stenotic graft lesions before graft occlusion.     

Long-term Outcome of a Cuffed Expanded PTFE Graft for Hemodialysis Vascular Access

BACKGROUND: Development of venous outflow stenosis has been a major obstacle in maintaining the patency of dialysis vascular grafts. In the present study, we retrospectively analyzed the long-term results of cuffed expanded polytetrafluoroethylene (ePTFE) and non-cuffed (standard) ePTFE grafts placed for hemodialysis access. MATERIALS AND METHODS: A total of 67 patients who underwent placement of either cuffed (n = 41) or standard (n = 26) ePTFE grafts were retrospectively analyzed. There were no significant differences between the two groups with regard to age, gender, cause of end-stage renal disease, and anatomic placement of the graft. Endpoints consisted of primary (without any intervention) and secondary (with radiological or surgical intervention) graft patency rates at 1-3 years. RESULTS: There was a trend toward better primary graft patency rates in the cuffed versus the standard ePTFE: 37.7% vs. 25.7% at 1 year, 35% vs. 10.3% at 2 years, 28% vs. 5.1% at 3 years, respectively (p = 0.086, Kaplan-Meier). Secondary patency rates in the cuffed group were significantly superior (p = 0.047) to those in the standard group (81.8% vs. 56.1% at 1 year, 61.8% vs. 46.3% at 2 years, 51.5% vs. 33.1% at 3 years, respectively). Thrombosis as a cause of complete graft failure was significantly higher (34%) in the standard group than in the cuffed group (9%) (p = 0.0125). CONCLUSIONS: Compared to the standard ePTFE, the cuffed ePTFE graft provided better long-term outcome, especially in terms of secondary patency rates after radiological intervention.     

Bypass graft to the midpopliteal artery with a combined anterior and posterior approach

PURPOSE: The medial supragenicular and infragenicular approaches to the popliteal artery were introduced almost 50 years ago and replaced the posterior approach to the popliteal artery for distal graft implantation. We review a contemporary series of bypass grafts to the midpopliteal artery by use of a combined anterior and posterior approach to evaluate its potential clinical benefits. TECHNIQUE: After the proximal graft anastomosis is constructed, an incision is made in the popliteal fossa to access the midpopliteal artery, the graft is passed into that incision, and all but the popliteal incision is closed. The patient is turned, the midpopliteal artery dissection is completed, and the graft is anastomosed distally. METHODS: Fifty-seven bypass grafts, implanted distally on the midpopliteal artery by this technique over a 13-year period, chosen in preference to an infragenicular bypass graft in selected patients when a supragenicular bypass was not feasible, were assessed in terms of indications for surgery, conduit type, complications, length of postoperative hospitalization, and graft patency. RESULTS: Bypass grafting originated from the axillary artery in two cases, the common iliac artery in one case, and the femoral artery in 54 cases. The procedure was performed in five patients with a popliteal trifurcation anomaly, nine patients with a blind popliteal segment, 20 patients with limited length of autologous vein, and five patients with an above-knee graft infection requiring an alternate path for revascularization. Autologous vein was used in 35 and polytetrafluoroethylene (PTFE) in 19 bypass grafts. Three other patients had a composite sequential femoral-popliteal-tibial bypass graft, with PTFE and autologous vein. Postoperative (30 day) complications include one death (composite sequential), one stroke (PTFE), and one graft thrombosis (saphenous vein). The mean postoperative hospitalization for the last 31 patients was 4.2 +/- 3.7 days. In the autologous vein group, the 1-year primary patency rate was 87%, and the primary assisted patency rate was 94%. In the PTFE group, the 1-year primary patency rate was 72%. Two composite sequential grafts remained patent at 1 year. CONCLUSIONS: Bypass grafting to the midpopliteal artery with a combined anterior and posterior approach offers a safe and effective option to below-knee bypass grafting when an above-knee bypass grafting is not feasible. Compared with the medial infragenicular incision, the posterior incision results in reduced morbidity rates, rapid mobilization, and early hospital discharge.     

Popliteal-to-distal bypass grafts for critical leg ischaemia

BACKGROUND: To assess the value of revascularization to crural and pedal arteries using the popliteal artery as inflow source. METHODS: Experimental design: Retrospective study with a mean follow-up period of 15.2 months (range, 0-46). Setting: Academic referral center. Patients: 62 patients with critical leg ischaemia and popliteal artery suitable as inflow source for infrapopliteal arterial revascularisation. Interventions: 66 popliteal-to-distal bypass procedures, of which 18 popliteal-crural bypass grafts and 48 popliteal-pedal bypass grafts. Main outcome measures: Bypass graft patency, leg salvage, survival and success defined as patients alive with leg. RESULTS: At 1-month, 1-year, and 2-year follow-up, the primary patency rates were 87%, 58%, and 55%, secondary patency rates were 95%, 70%, and 67%, leg salvage rates were 97%, 88%, and 88%, while 88%, 70%, and 66% of patients were alive with legs at the same intervals. At 2-year follow-up the survival rate was 72%. Above-knee popliteal-to-distal bypasses achieved better primary patency (p=0.02) and corrected primary patency rates (p=0.01) than below-knee popliteal-to-distal bypasses. Diabetes and uraemia affected the survival and patients alive with leg rates. CONCLUSIONS: Popliteal-to-distal bypass surgery is worthwhile for the management of severe, isolated infrapopliteal atherosclerotic disease. Diabetic and uraemic patients are at high risk for both leg and life loss after revascularisation. Grafts originating from the above-knee popliteal artery may achieve better patency rates than those originating from the below-knee popliteal artery.     

Composite sequential grafts for femorocrural bypass reconstruction: experience with a modified technique

BACKGROUND: To evaluate the efficacy of a modification of the composite sequential femorocrural bypass graft that we adopted in 1985, a retrospective case-note study was undertaken. The grafts combined a prosthetic femoropopliteal section with a popliteal to crural section with autologous vein, linked via a common intermediate anastomosis sited on the above-knee popliteal artery. PATIENTS AND METHODS: Between 1985 and 2000, 68 grafts of this type were constructed in 65 patients with critical ischemia of the lower limb and insufficient autologous vein for construction of an all venous bypass. Reasons for insufficient long saphenous vein included previous lower limb bypass in 33 cases, phlebitis in 16 cases, venous hypoplasia in eight cases, and previous varicose vein surgery in seven cases. Distal anastomoses were carried out to the peroneal artery in 26 cases, the anterior tibial artery in 17 cases, the posterior tibial artery in 17 cases, and the pedal arteries in eight cases. Sources of vein included the long saphenous vein in 26 cases, the arm vein in 38 cases, and the short saphenous vein in two cases. In 22 limbs (32%), angiography had shown an occluded segment of above-knee popliteal artery, and in these cases, local popliteal disobliteration was performed to receive the composite anastomosis and to provide additional outflow. RESULTS: The 2-year cumulative primary patency, secondary patency, and limb salvage rates were 68%, 73%, and 75%, respectively. Localized popliteal disobliteration did not compromise graft patency (P =.07, with log-rank test). CONCLUSION: In the absence of sufficient autologous vein, patients needing bypass to crural arteries can be offered reconstruction with composite sequential grafting with satisfactory results. Furthermore, an occluded above-knee popliteal segment is not a contraindication for composite sequential bypass reconstruction.     

Long-term outcome of revised lower-extremity bypass grafts.

PURPOSE: Reversed lower-extremity vein grafts (LEVGs) frequently require operative revisions to maintain patency. Identifying grafts that are at risk, however, requires an intensive duplex scanning-based surveillance program. Excellent 5-year graft patency and limb-salvage rates have previously been reported in patients undergoing graft revisions, but results beyond 5 years are essentially unknown, a factor that is of importance in an increasingly aging population. This study was performed to determine the results of surgical revisions of LEVGs after a follow-up as long as 10 years. METHODS: All patients undergoing placement of a LEVG were observed in a program of duplex scanning-based surveillance as long as the patient remained a candidate for graft revision. Grafts were considered for revision on the basis of the presence of focal areas of increased velocity, a prestenotic to intrastenotic velocity ratio more than 3.0, or uniformly low velocities throughout the graft. All lesions were confirmed with preoperative arteriography before revision. Assisted primary patency, limb-salvage, and survival rates were determined by means of Kaplan-Meier analysis in all patients who underwent LEVG revision from January 1990 to December 2000. RESULTS: A total of 1498 LEVG procedures were performed during the study period. A total of 330 surgical graft revisions were performed on 259 extremities in 245 patients. The median follow-up period was 38 months. The assisted primary patency rate of all grafts, the limb-salvage rate for patients undergoing surgery for limb-salvage indications, and the survival rate of all patients were 87.4%, 88.7%, and 72.4%, respectively, 5 years after the original bypass grafting procedure, 85.7%, 83.4%, and 67.8%, respectively, 7 years after the original bypass grafting procedure, and 80.4%, 75.4%, and 53.4%, respectively, 10 years after the original bypass grafting procedure. A total of 180 revisions (55%) were performed during the first year, 110 (33%) between the first year and the fifth year, and 40 revisions (12%) were performed on grafts older than 5 years. LEVGs revised within the first year after bypass grafting had lesions within the graft in 78%, in the native arterial inflow in 10%, and in the native arterial outflow in 12%. This differed significantly from the location of lesions in revisions performed between 1 and 5 years and after 5 years (graft, 63% and 62%; inflow, 20% and 19%; outflow, 17% and 19%; P >.05, Chi-square). CONCLUSION: Excellent assisted primary patency and limb-salvage rates can be achieved for as long as 10 years in LEVGs that require revision, with only a 7% drop in overall patency and limb-salvage rates between the fifth and 10th years. Although most revisions were required within the first year, 34% were performed between the first year and the fifth year, and 11% after 5 years. These data support the growing body of evidence that favors an aggressive regimen of duplex scanning surveillance of LEVGs for the life of the graft. Revised grafts have excellent patency through 10 years.     

Patency Rates of Cuffed and Noncuffed Extended Polytetrafluoroethylene Grafts in Dialysis Access: A Prospective,Randomized Study

Background  Although autogenous arteriovenous fistulae are the optimal route for dialysis access, extended polytetrafluoroethylene (ePTFE) grafts continue to be the preferred access for patients without suitable superficial veins. Among the common complications related to dialysis grafts, thrombosis due to graft outlet stenosis is the most frequently encountered clinical problem. A cuffed graft was designed to eliminate the outflow turbulence to reduce outlet stenosis and to enhance the clinical patency of ePTFE grafts. We conducted a prospective, randomized study to compare the clinical outcomes of cuffed ePTFE grafts and noncuffed grafts in dialysis access. Methods  Between November 2004 and October 2005, 89 ePTFE grafts were implanted for hemodialysis access in the upper extremities of end-stage renal patients. Graft selection was randomized, with patients receiving a cuffed graft (Venaflo) or a regular noncuffed graft (Stretch Gore-Tex). All patients were monitored for signs of thrombosis or other complications. Primary and secondary graft patency was analyzed by using a life-table analysis, and the log-rank test was applied to compare graft patencies. Results  Demographic data for both groups were similar without statistical difference. The primary patency rates and secondary patency rates at 12 months after implantation were 56% and 91% for cuffed grafts, and 41% and 78% for noncuffed grafts, respectively. The cuffed group outperforms the noncuffed group regarding primary and secondary patencies statistically. However, the incidence of other complications that required further surgery was similar in both groups. Conclusions  This investigation revealed that the cuffed ePTFE graft, which was designed to decrease graft outlet stenosis, may enhance the clinical patency rates of dialysis grafts.     

Prosthetic above-knee femoropopliteal bypass grafting: five-year results of a randomized trial

PURPOSE: This trial was designed to identify factors affecting patency rates of primary prosthetic above-knee femoropopliteal bypass grafts at 5 years. METHODS: A multi-institutional, prospective trial randomized 240 patients to compare patency rates of Gore-tex and Hemashield above-knee femoropopliteal bypass grafts at 5 years. Univariate comparisons of patency between levels of each prognostic variable were made with the Kaplan-Meier method. Variables that had a univariate P value less than.25 or those known to be important were submitted to a Cox regression analysis. RESULTS: The patient survival rate at 5 years was 59.4%. There were no differences in primary or secondary patency rates at 5 years between the two graft materials (primary, 45% vs 43% and secondary, 68% vs 68%). The risk for graft occlusion was significantly increased for patients younger than 65 years (2.1; P =.001) and for grafts with a diameter less than 7 mm (1.65; P =.0219). Variables with no apparent independent effect on patency rates were smoking status, runoff, diabetes mellitus, sex, presenting symptoms, and postoperative treatment with aspirin or Coumadin. Noninvasive test results were not predictive of subsequent graft function. CONCLUSION: Although the type of prosthetic used for above-knee femoropopliteal bypass grafts does not affect 5-year patency rates, age and graft size do influence results. These factors should be considered before a prosthetic bypass grafting procedure. Furthermore, these data should serve as a contemporary standard, with which evolving and conventional procedures can be compared.     

Surgical reconstruction of iliofemoral veins and the inferior vena cava for nonmalignant occlusive disease

PURPOSE: Venous reconstructions are rarely performed, and factors affecting long-term results of bypass grafts implanted in the venous system are not well defined. In this report we updated our experience. METHODS: The clinical data of all patients who underwent venous reconstruction for iliofemoral or inferior vena caval (IVC) occlusion due to nonmalignant disease between January 1985 and June 1999 were retrospectively reviewed. Patients were classified, and outcomes were compared according to the guidelines of the Joint Vascular Societies. RESULTS: Forty-two patients, 23 males and 19 females (mean age, 40 years; range, 16-81), underwent 44 venous reconstructions. Thirty-six patients had limb swelling or venous claudication, 38 had pain, and 14 had healed or active ulcers. The cause of obstruction was congenital in two and acquired in 40 (deep vein thrombosis, 25; trauma, 5; retroperitoneal fibrosis, 4; IVC occlusion devices, 4; others, 2). Eighteen patients underwent saphenous vein crossover grafts (Palma procedure), 17 had expanded polytetrafluoroethylene (ePTFE) grafts implanted (femorocaval, 8; iliocaval, 5; crossfemoral, 3; cavoatrial, 1), 6 patients had spiral vein grafts (5 iliac/femoral and 1 cavoatrial), and 1 underwent femoral vein patch angioplasty. Clinical follow-up averaged 3.5 years (median, 2.5), and graft follow-up with imaging studies averaged 2.6 years (median, 1.6). Seven patients were lost to follow-up. The secondary 3-year patency rate for all reconstructions was 62%. Palma procedures had a 4-year patency rate of 83%. The secondary patency rate of iliocaval and femorocaval ePTFE bypass grafts at 2 years was 54%. The secondary patency was lower in patients with an arteriovenous fistula (P =.023). All ePTFE grafts had a 45% patency rate at 2 years, not significantly different from saphenous vein grafts (83%, P =.16). Clinical scores improved with graft patency (median, 0.0 vs 1.5; P =.044). CONCLUSIONS: Venous reconstructions for iliofemoral or IVC obstruction offer 3-year patency rates of 62%. The Palma procedure with autologous saphenous vein had the best long-term patency, whereas long-term success with ePTFE was moderate. The use of an arteriovenous fistula to improve graft patency remains controversial.     

Long-term results of above knee femoro-popliteal bypass depend on indication for surgery and graft-material.

OBJECTIVE To determine the long-term results of above-knee femoro-popliteal bypass with autologous saphenous vein (SV) or expanded polytetrafluoroethylene (ePTFE) in routine surgical practice. METHODS: Data from the Swedish vascular registry, Swedvasc, was reviewed retrospectively. Patients with bypass surgery in 1996 and 1997 were assessed 5-7 years later. Data were gathered from the case-records and from clinical follow-up. The composite endpoint of graft failure included death within 30 days, occlusion, major amputation, extension of the graft to below-knee position and removal of an infected graft. Kaplan-Meier curves and Cox' proportional hazard ratios were calculated. RESULTS: Four hundred and ninety-nine patients undergoing bypass for critical limb ischemia (CLI) (56%) or claudication (44%), SV (28%) or ePTFE (72%), were included. There were no significant differences in patient characteristics between patients with SV or ePTFE. CLI and ePTFE were risk factors for graft failure. For patients with both claudication and CLI SV grafts yielded better long-term results than ePTFE grafts ( p <0.03) and ( p <0.003), respectively. Symptom aggravation after graft occlusion was almost exclusively restricted to ePTFE grafts. CONCLUSIONS: Femoro-popliteal bypass above-knee with SV gives good long-term results, especially for claudication. ePTFE grafts cannot be recommended in claudicants, since occlusion occurs often and frequently leads to CLI.     

Patency and limb salvage after infrainguinal bypass with severely compromised ("blind") outflow

HYPOTHESIS: Infrainguinal graft patency and limb salvage are adversely affected by severely compromised outflow. DESIGN: Retrospective review of all infrainguinal bypass procedures performed at a single institution during a 5-year period. SETTING: University teaching hospital. PATIENTS: Two hundred seventy-four patients underwent infrainguinal bypass for limb salvage (351 grafts in 307 limbs). INTERVENTIONS: All infrainguinal bypasses originated from a femoral artery. The distal anastomosis in 279 grafts was located in an artery with at least 1 patent outflow vessel with anatomically normal end-artery runoff (Society for Vascular Surgery/International Society for Cardiovascular Surgery ad hoc committee runoff score, 1-9). The distal anastomosis of 72 grafts was located in an artery with only collateral outflow ("blind bypass"; runoff score, 10). MAIN OUTCOME MEASURES: Perioperative morbidity and mortality, primary-assisted and secondary graft patency, limb salvage, and survival. RESULTS: All data are presented as mean +/- SEM. Patients undergoing blind bypass were older (age, 70 +/- 2 vs. 66 +/- 1 years; P <.05) and had a higher incidence of hypertension (90% vs 70%; P <.05) and end-stage renal disease (24% vs. 13%; P <.05). Comparing patients undergoing blind bypass to bypass with at least 1 patent outflow vessel, there were no differences in the use of nonautogenous conduits (50% vs 59%; P =.21) or postoperative warfarin (30% vs 32%; P =.69), or in perioperative mortality rates (2.7% vs 3.2%; P =.79). After a median follow-up of 13 months (range, 0-60 months), 2-year secondary graft patency for the entire group was 63% +/- 4%. The secondary patency rate of blind bypass grafts was no different from that of grafts with at least 1 patent outflow vessel (67% +/- 7% vs. 64% +/- 4%; P was not significant). However, the 2-year limb salvage rate in limbs with blind outflow was significantly worse than in limbs with at least 1 patent outflow vessel (67% +/- 7% vs. 76% +/- 3%; P =.04). CONCLUSION: Acceptable long-term patency rates can be achieved in infrainguinal bypass grafts with blind outflow, although blind outflow remains a marker for subsequent limb loss in the chronically ischemic leg.     

Randomized clinical trial of distal anastomotic interposition vein cuff in infrainguinal polytetrafluoroethylene bypass grafting

BACKGROUND: The aim was to examine the effect of a Miller vein cuff at the distal anastomosis on the medium- to long-term patency and limb salvage rates of femoral to above-knee and femoral to below-knee popliteal artery polytetrafluoroethylene (PTFE) bypasses. METHODS: This study involved extended follow-up of the original cohort of patients included in a previously reported multicentre randomized clinical study. Outcome measures were bypass graft patency and limb salvage. RESULTS: Two hundred and sixty-one bypass operations were originally randomized. For this study, full data were available on 235 (120 with a Miller cuff, 115 without). The cumulative 5-year patency rate for above-knee bypasses with a Miller cuff was 40 per cent, compared with 42 per cent for non-cuffed bypasses (P = 0.702). The cumulative 3-year patency rate for below-knee bypasses with a Miller cuff was 45 per cent, compared with 19 per cent for non-cuffed bypasses (P = 0.018). A Miller cuff had no significant effect on limb salvage for above-knee or below-knee bypasses. CONCLUSION: Three-year patency rates of femoral to below-knee popliteal PTFE bypasses were improved by a Miller cuff. Miller cuffs had no effect on patency rates for femoral to above-knee popliteal bypasses at 5 years and did not improve limb salvage in either group.     

Meta-analysis of femoropopliteal bypass grafts for lower extremity arterial insufficiency

BACKGROUND: In femoropopliteal bypass surgery, the use of saphenous vein grafts is preferable, but synthetic grafts are widely used above the knee. The objective of this meta-analysis was to assess the long-term patency of femoropopliteal bypass grafts classified as above-knee polytetrafluoroethylene, above-knee saphenous vein, or below-knee saphenous vein. METHODS: Studies published from 1986 through 2004 were identified from electronic databases and reference lists; 73 articles contributed 1 or more series that used survival analysis, assessed femoropopliteal bypasses in one of the foregoing configurations, reported a 1-year graft patency rate, and included at least 30 bypasses. The series with a predominance of claudicant patients were included in meta-analysis C, and the series in which critical ischemia predominated were included in meta-analysis CI. Pooled survival curves of graft patency were constructed. RESULTS: In meta-analysis C, the pooled primary graft patency was 57.4% for above-knee polytetrafluoroethylene, 77.2% for above-knee vein, and 64.8% for below-knee vein at 5 years; there was a significant difference between above-knee grafts at 3, 4, and 5 years (P < .05). The corresponding pooled secondary graft patency was 73.2%, 80.1%, and 79.7%, respectively (P > .05). In meta-analysis CI, the pooled primary graft patency was 48.3% for above-knee polytetrafluoroethylene, 69.4% for above-knee vein, and 68.9% for below-knee vein at 5 years; there was a significant difference between above-knee grafts until 4 years (P < .05). The corresponding pooled secondary graft patency was 54.0%, 71.9%, and 77.8%, respectively, with a significant difference between above-knee grafts at 2, 3, and 4 years (P < .05). CONCLUSIONS: The great saphenous vein performs better than polytetrafluoroethylene in femoropopliteal bypass grafting and should be used whenever possible.