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.     

肝素涂层人工血管在腔内治疗失败的严重下肢缺血血运重建中的应用

目的:评价肝素涂层人工血管在腔内治疗失败的严重下肢缺血(CLI)患者行下肢动脉旁路移植术中的疗效。方法:回顾性分析2017年10月至2019年4月北京医院血管外科收治的腔内治疗失败的CLI患者行下肢动脉旁路移植术治疗的临床资料,根据患者临床症状、病变特点,选择个性化治疗方案,包括支架取出术、动脉内膜剥脱和成形术、人工血管或人工血管复合自体静脉旁路移植术等多种手术方式完成下肢动脉血运重建。分析围术期并发症、症状缓解和溃疡伤口愈合情况、桥血管通畅率及保肢率。结果:入组患者共27例,其中16例静息痛患者术后疼痛均有效缓解,11例有足部溃疡和组织坏死者中,9例完全愈合,2例术后半年溃疡面缩小。术后并发症6例,术后30 d无死亡病例。所有患者获得随访,随访时间为(13.0±8.9)个月(范围:2~35个月)。通过Kaplan-Meier曲线计算,术后6、12及24个月一期通畅率分别为83.3%、73.7%及49.1%;二期通畅率分别为91.8%、82.1%及70.8%;保肢率分别为91.8%、86.9%及76.6%。其中15例股-腘动脉旁路移植术术后1、2年一期通畅率分别为86.7%、49.5%;二期通畅率分别为93.3%、81.7%;保肢率分别为93.3%、81.7%。8例股-小腿动脉旁路移植术术后1、2年一期通畅率分别为45.0%、45.0%;二期通畅率分别为58.3%、58.3%;保肢率分别为58.3%、58.3%。结论:肝素涂层人工血管动脉旁路移植术为腔内治疗失败的下肢动脉复杂病变提供了一种安全有效的治疗方式,能够有效缓解症状及提高保肢率。     

Autologous saphenous vein and heparin-bonded expanded polytetrafluoroethylene as graft materials for below-the-knee femoro-popliteal bypass in patients with critical limb ischemia: A propensity score-matched analysis

ObjectiveTo compare the outcomes of heparin bonded expanded polytetrafluoroethylene (HePTFE) and autologous saphenous vein (ASV) in patients undergoing below-knee (BK) femoro-popliteal bypass for critical limb ischemia (CLI).DesignRetrospective single-centre matched case–control study.MethodsFrom 2003 to 2019, 275 consecutive BK bypasses for CLI were performed, 109 with the ASV and 166 with a HePTFE graft. All the baseline characteristics that were reliably measured and were potentially relevant in the decision-making process were included as confounders in a logistic regression model and the factors that were significantly different between the two groups then used to perform a propensity matching analysis. Propensity score-based matching was performed in a 1:1 ratio to compare outcomes. Arterial hypertension, hyperlipemia, the need for tibial anastomosis at the distal level and the run-off status were the covariates included in the matching. Follow-up outcomes were estimated by Kaplan–Meier methods and compared with log rank test.ResultsAfter propensity matching, 101 HePTFE bypasses were matched with 101 ASV bypasses. The median duration of follow-up was 37 months (range 1–192). The 5-year survival rate was 67.5% (standard error (SE) 0.05) in the HePTFe group and 64.5% (SE 0.06) in the ASV group (p = 0.8, log rank 0.04). Primary patency rates were 38% (SE 0.06) in the HePTFE group and 41% (SE 0.06) in the ASV group (p = 0.7, log rank 0.3). Also assisted primary patency and secondary patency rates did not differ in the two groups. Amputation-free survival was 53% (SE 0.05) in the HePTFE group and 58% (SE 0.06) in the ASF group (p = 0.6, log rank 0.2).ConclusionsHePTFE provided 5-year similar results to those obtained with use of the ASV in equivalent patients with CLI undergoing below-knee or tibial bypass.     

Six year experience with expanded polytetrafluoroethylene arterial grafts for limb salvage

We have used 822 polytetrafluoroethylene (PTFE) grafts in arterial reconstructions for limb salvage over the last 6 years at Montefiore Medical Center-Albert Einstein College of Medicine, Four hundred and twenty-seven femoropopliteal reconstructions with PTFE had a 6 year cumulative life table patency rate of 55% with follow-up of 76 grafts for more than 3 years and 28 grafts for more than 4 years. Seventy-nine bypasses to the isolated popliteal segment had a 6 year cumulative patency rate of 72%. There were 207 bypasses performed to the tibial, peroneal or dorsalis pedis arteries. Life table patency rates were 55% at 1 year, 40% at 2 years and 37% at 4 years. Ninety-two PTFE femorofemoral and 62 axillofemoral bypasses had 5 1/2 year cumulative life table patency rates of 83% and 75%, respectively. Axillopopliteal PTFE bypasses can salvage otherwise doomed limbs. Thirty-four such grafts had 74% 1 year and 45% 5 year patency rates. The overall infection rate in all 822 PTFE grafts was only 0.5%. Thus, PTFE is a promising vascular prosthetic material which facilitates otherwise difficult or impossible limb salvage procedures.     

Three year experience with expanded polytetrafluoroethylene arterial grafts for limb salvage

Polytetrafluoroethylene grafts were used for 175 femoropopliteal reconstructions with a cumulative 3 year life table patency rate of 77 percent. Reoperation for early or late failure was required in 27 patients to achieve this patency rate. If these 27 failures were calculated as nonpatent grafts, 3 year patency would be 62 percent. Thirty month life table patency rates were 94 and 91 percent for polytetrafluoroethylene axillofemoral and femorofemoral bypasses, respectively. Twenty-two polytetrafluoroethylene axillopopliteal bypasses were performed because of infection in the groin, previously failed reconstructions or unavailability of femoral vessels due to disease. The 2 year life table patency rate was 69 percent, with nine of the grafts patent for more than 1 year. Forty polytetrafluoroethylene bypasses to arteries at the ankle or in the foot resulted in a 2 year life table patency rate of 48 percent. Thus, polytetrafluoroethylene grafts show early promise as a vascular prosthesis. Although further study will be required to define the exact role of this new arterial substitute, it already can facilitate the performance of otherwise difficult or impossible limb salvage procedures.     

Remote arteriovenous fistula with infrapopliteal polytetrafluoroethylene bypass for critical ischemia

Between January 1985 and January 1989, 13 patients underwent femorotibial bypass using a polytetrafluoroethylene graft with a remote distal arteriovenous fistula. Indications for operation were gangrene in six patients, rest pain in five patients, and nonhealing ulcer in two patients. No patient had a usable autogenous saphenous vein. Eight patients had a previous failed femorodistal bypass. Standard femorotibial bypass was performed using a 6 mm thin-walled polytetrafluoroethylene graft. The distal remote arteriovenous fistula was done on the same artery. Warfarin was given postoperatively. Graft patency was assessed by duplex scan and digital arteriography. There was no postoperative mortality. All grafts and fistulas remained patent initially with improvement in symptoms and limb salvage. In the follow-up period there was continued graft patency in all but two patients who had a below-knee amputation. Three patients died with a patent graft. In two additional patients the graft remained patent but the fistula closed. We believe that in selected situations, the remote distal arteriovenous fistula is a potentially valuable adjunct for obligatory polytetrafluoroethylene femorotibial bypass.     

Clinical experience with expanded polytetrafluoroethylene (Gore-Tex) grafts for femoropopliteal arterial bypass

Thirty-seven grafts of expanded polytetrafluo-roethylene were implanted in 28 patients in whom autogeneous saphenous vein was not available, either for symptoms of severe claudication or limb salvage. The length of follow-up ranges from 8 to 28 months. The patency rate is 86.9 percent for the patients with severe claudication and 71.4 percent in the limb salvage group; the overall patency rate is 81 percent. We believe that expanded polytetrafluoroethylene is a good prosthetic substitute when autogenous vein is unavailable.     

High-Porosity expanded polytetrafluoroethylene grafts with omentum wrap for portal vein replacement: Intermediate results

The purpose of this study was to examine the intermediate (6-month) patency and healing characteristics of high-porosity expanded polytetrafluoroethylene (ePTFE) grafts with and without omentum wrap in a dog portal vein replacement model, compared with short-term (1-month) results. The grafts, either wrapped by omentum or not, were placed as portal vein replacements in 22 mongrel dogs. After 1 and 6 months, the grafts were retrieved and examined for patency and subjected to pathology study. Although the short-term patency rate in all grafts was 100%, regardless of the presence or absence of omentum wrap, the intermediate patency of high-porosity ePTFE without omentum wrap was very poor (20%). On the other hand, high-porosity ePTFE with omentum wrap had an intermediate patency rate of 100%. At 6 months, the high-porosity ePTFE grafts with omentum wrap were completely healed. The pseudointima was entirely replaced by thin fibrous tissue, with complete endothelial-like cell coverage throughout the graft. This result suggests that high-porosity ePTFE with omentum wrap could be a suitable prosthetic alternative to autogenous vein graft in portal vein reconstruction.     

Recent trends in bypass surgery performed in patients with critical limb ischemia

Recently, many candidates for infrainguinal bypass surgery have been patients with diabetes and tended to have ischemic tissue loss or gangrene. In the management of these patients, many technical strategies are required to obtain a good outcome after bypass surgery. The predisposing region of diabetic atherosclerosis is typically the tibial artery trunk and crural arteries. Inframalleolar bypass is ideal to supply the maximum blood flow to the foot. For this purpose, in situ bypass surgery has been the first choice since the advent of the LeMaitre valve cutter. Combined inflow percutaneous transluminal angioplasty and distal bypass are indicated for patients with a TASC A lesion in the iliac artery or superficial femoral artery. This procedure is advantageous especially for patients with end-stage renal disease (ESRD) to decrease the surgical invasiveness and to preserve the autogenous vein. Patients with ESRD usually have severe calcification of the intrinsic foot artery and sometimes a dual bypass to the pedal arteries are useful to expedite healing. Meticulous topical debridement after bypass surgery is also essential for accelerating the healing process. In this situation, negative-pressure wound drainage is currently used worldwide. Free tissue transfer, which is often combined with bypass, is another armament to salvage a severely gangrenous foot.     

Autogenous venous bypass grafts and limb salvage: 5-year results in 1971 and 1991

Claims have been made that the increased utilization of arterial reconstruction has not resulted in improved limb salvage. This report compares the resultsss of two series of patients with autogenous venous bypass grafts and examines the institutional trends at a major regional vascular center with these procedures. The two groups of patients underwent operation between 1957 and 1964 (group I) and 1982 and 1985 (group II) respectively. Each patient was followed for a minimum of 5 years or until death. This review showed that the demographics of the population and the nature of the operation changed dramatically over the 20-year period. Patients were older, had more medical co-morbid conditions, more operations were performed for salvage and more to vessels below the knee joint in the latter series. Despite these adverse factors, the 30-day patency rates were significantly better in the later group, 93% versus 76%. Likewise, limb salvage rates were improved both initially and after the 5-year period of observation. The 5-year primary patency, however, was no different between groups I and II, 60% versus 56%. Since both series preceded the use of duplex scanning for graft surveillance, even further improvements in both graft patency and limb salvage rates would be expected in patients currently treated.     

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.     

Platelet activation in bypass surgery for critical limb ischemia

Platelet activation contributes to graft occlusion after bypass surgery. This study investigated platelet activation status before, during, and after bypass. Blood was taken preoperatively from patients undergoing femoro-popliteal bypass and at incision, after dissection, after ischemia, after reperfusion, 24 hours after surgery, and almost 2 years after bypass (and given aspirin or warfarin). Platelet aggregation was measured using a turbidimetric method and platelet activation with flow cytometry. Statistical analysis was performed using Mann-Whitney U and Wilcoxon's tests. Resting platelet activation was similar between controls and patients undergoing bypass. Platelet activation decreased at incision but remained highly reactive. Platelet aggregation increased after dissection and the ischemic phase but significantly decreased after reperfusion. Platelet aggregation and activation were increased at 24 hours and subsequently after bypass. Platelets in critical limb ischemia exist in the primed state and become activated by minimum stimuli. Increased platelet activation occurs after bypass grafting for critical limb ischemia despite adjunctive therapy.     

Infrainguinal bypass for critical limb ischemia: tips and tricks

A thoughtful but aggressive approach to care of patients with critical limb ischemia (CLI) is required to alleviate lower-extremity pain/tissue injury and achieve durable limb salvage. Specific subsets of CLI patients have been identified to clearly benefit from open surgical revascularization based on presenting signs (extensive tissue loss), multi-level, long-segment arterial occlusive disease, healthy saphenous conduit, and nondiseased tibial artery target vessel with continuous patency to the pedal arch. When other clinical scenarios exist, the treatment strategy requires consideration of patient’s medical and surgical risk factors, anatomic distribution of atherosclerotic disease, and the clinical status of the limb affected by CLI. Infrainguinal saphenous vein bypass is the most durable technique for limb salvage and when properly performed is associated with excellent wound healing rates and improvement in quality of life. In this review, we detail our approach to infrainguinal arterial vein bypass in patients with CLI, including patient selection criteria, surgical planning based on arterial imaging studies, and operative technical requirements required for successful open lower-extremity bypass procedures.     

Subintimal angioplasty for the treatment of claudication and critical limb ischemia: 3-year results

OBJECTIVE: Subintimal angioplasty (SIA) is an increasingly used method of lower extremity revascularization for patients with chronic arterial occlusions. To assess the technical feasibility, safety, and 3-year outcomes of patients treated with SIA, we performed a retrospective review of our early experience. METHODS: Patient information-including demographics, indications, procedures, noninvasive arterial studies, and postprocedural events-was recorded in a database. Outcomes were determined on an intention-to-treat basis, as well as by technical success, by using Kaplan-Meier survival analysis. Continuous data were compared by using the Student t test, and survival curves were compared by log-rank testing. RESULTS: From December 2002 through December 2003, 104 patients (105 limbs) underwent SIA of 159 occlusive lesions involving the iliac (n = 10), superficial femoral (n = 85), popliteal (n = 48), or tibial (n = 16) arteries. Sixty-six (62.9%) patients were treated for critical limb ischemia, and 39 patients (37.1%) were treated for disabling claudication. Technical success was achieved in 91 procedures (86.7%) and resulted in a mean increase in ankle-brachial index of 0.36 +/- 0.16. The mean follow-up was 23.4 months (range, 0-46 months). During this period, 18 patients (17.0%) died, and 15 amputations (14.3%) were performed, 6 of which were performed for patients on whom SIA had been unsuccessful. In patients undergoing successful SIA, the primary patency was 55%, 43%, and 35% at 12, 24, and 36 months, respectively. Twenty-one patients underwent a total of 23 percutaneous procedures to maintain or restore patency of the SIA during the study period. This resulted in secondary patency rates of 71%, 63%, and 51% at 12, 24, and 36 months, respectively. Multivariate analysis revealed critical limb ischemia to be the only predictor of reduced primary patency. Fifteen patients with inoperable critical limb ischemia underwent successful SIA. Limb salvage in this group was 54% and 43% at 12 and 36 months, respectively. Limb salvage in operative candidates was 100% and 88% at the same intervals. In patients with disabling claudication, 94% experienced improvement in symptoms 3 months after the procedure, and 68% of patients reported sustained improvement at 36 months. In all operative candidates successfully treated with SIA, freedom from surgical bypass was 83% and 73% at 12 and 36 months, respectively. CONCLUSIONS: SIA for the treatment of lower extremity chronic arterial occlusions is technically feasible, results in minimal morbidity, and provides satisfactory revascularization without surgical bypass. Secondary patency is comparable to that of autologous vein bypass and is achieved with a low rate of reintervention. When used as first-line therapy, SIA provides most patients with limb salvage and freedom from surgical bypass at 3 years.     

Carotid bypass with polytetrafluoroethylene grafts: a study of 110 consecutive patients

BACKGROUND: Carotid endarterectomy (CEA) is the standard treatment for atherosclerotic lesions involving the carotid bifurcation. However, CEA can be challenging under some conditions. We describe the technique and outcome of prosthetic carotid bypass grafting (PCB) with polytetrafluoroethylene (PTFE) grafts as an elective alternative to CEA. PATIENTS AND METHODS: This retrospective analysis of prospectively collected data came from a series of 110 consecutive PCBs, that is, 9.6% of 1140 carotid revascularization procedures performed in our department between September 1986 and July 2002. Primary indications for PCB were extensive atherosclerotic lesions (n = 45, 40.9%), carotid stenosis associated with kinking (n = 29, 26.4%), recurrent stenosis (n = 18, 16.4%), and stenosis after radiation therapy (n = 7, 6.4%). RESULTS: The combined stroke and death rate at 30 days was 0.9%. Mean duration of follow-up was 647 +/- 71 days. Four carotid bypass grafts (3.6%) became occluded, and stenosis recurred in 1 (0.9%). At 3 years, overall actuarial survival was 81.4 +/- 11.5 and actuarial stroke-free rate was 97.7 +/- 2.3. There were no fatal strokes. CONCLUSION: PCB is a viable technique for treatment of extensive atherosclerotic carotid lesions, recurrent carotid stenosis, and carotid stenosis after radiation therapy. Postoperative stroke, occlusion, and recurrent stenosis rates are comparable to those associated with CEA performed under optimal conditions.