Prosthetic Bypass Research Articles

A systematic review and meta-analysis of revascularization outcomes of infrainguinal chronic limb-threatening ischemia

BackgroundThe optimal strategy for revascularization in infrainguinal chronic limb-threatening ischemia (CLTI) remains debatable. Comparative trials are scarce, and daily decisions are often made using anecdotal or low-quality evidence. MethodsWe searched multiple databases through May 7, 2017, for prospective studies with at least 1-year follow-up that evaluated patient-relevant outcomes of infrainguinal revascularization procedures in adults with CLTI. Independent pairs of reviewers selected articles and extracted data. Random-effects meta-analysis was used to pool outcomes across studies. ResultsWe included 44 studies that enrolled 8602 patients. Periprocedural outcomes (mortality, amputation, major adverse cardiac events) were similar across treatment modalities. Overall, patients with infrapopliteal disease had higher patency rates of great saphenous vein graft at 1 and 2 years (primary: 87%, 78%; secondary: 94%, 87%, respectively) compared with all other interventions. Prosthetic bypass outcomes were notably inferior to vein bypass in terms of amputation and patency outcomes, especially for below knee targets at 2 years and beyond. Drug-eluting stents demonstrated improved patency over bare-metal stents in infrapopliteal arteries (primary patency: 73% vs 50% at 1 year), and was at least comparable to balloon angioplasty (66% primary patency). Survival, major amputation, and amputation-free survival at 2 years were broadly similar between endovascular interventions and vein bypass, with prosthetic bypass having higher rates of limb loss. Overall, the included studies were at moderate to high risk of bias and the quality of evidence was low. ConclusionsThere are major limitations in the current state of evidence guiding treatment decisions in CLTI, particularly for severe anatomic patterns of disease treated via endovascular means. Periprocedural (30-day) mortality, amputation, and major adverse cardiac events are broadly similar across modalities. Patency rates are highest for saphenous vein bypass, whereas both patency and limb salvage are markedly inferior for prosthetic grafting to below the knee targets. Among endovascular interventions, percutaneous transluminal angioplasty and drug-eluting stents appear comparable for focal infrapopliteal disease, although no studies included long segment tibial lesions. Heterogeneity in patient risk, severity of limb threat, and anatomy treated renders direct comparison of outcomes from the current literature challenging. Future studies should incorporate both limb severity and anatomic staging to best guide clinical decision making in CLTI.

The outcomes of prosthetic bypass grafting for chronic mesenteric ischemia.

This study aims to analyze early and late outcomes of the prosthetic bypass grafting procedure in the treatment of chronic mesenteric ischemia. Twenty-two patients (15 males, 7 females; mean age 60±10 years; range, 32 to 78 years) who underwent prosthetic bypass grafting for chronic mesenteric ischemia due to atherosclerosis between March 2009 and March 2017 were included in this study. The demographic and operative data were analyzed retrospectively. The most common risk factors for atherosclerosis were hypertension, diabetes, and hyperlipidemia. A total of 72% of the patients were active tobacco users. The common symptoms were postprandial angina and weight loss. Six patients (27%) had a history of endovascular intervention for mesenteric revascularization. Celiac artery bypass grafting was performed in 17 patients, while superior mesenteric artery bypass grafting was performed in 21 patients. Retrograde bypass was done in all patients and polytetrafluoroethylene grafts were used in 20 patients (90%). The mean hospital stay was 10.5 days and the mean follow-up was 44.7 months. The most common postoperative complications were respiratory failure (9%) and infection (9%). In-hospital mortality was observed in one patient (%4.5)who had acute myocardial infarction-related low cardiac output. One patient had graft thrombosis resulting in early graft infection a month after discharge. Late graft thrombosis was observed in two patients at 44 and 85 months, respectively. Late mortality was observed in two patients due to malignancy and cerebral bleeding, respectively. Prosthetic bypass grafting via open surgery for chronic mesenteric ischemia seems to be an effective treatment in long-term and can be implemented with low surgical risks.

One-Year Results of First-Line Treatment Strategies in Patients With Critical Limb Ischemia (CRITISCH Registry)

Purpose: To examine the outcomes of all first-line strategies for the treatment of critical limb ischemia (CLI), identify factors that influenced the treatment choice, and determine the risk of amputation or death after each treatment. Methods: CRITISCH (ClinicalTrials.gov identifier NCT01877252) is a multicenter, national, prospective registry evaluating all available treatment strategies applied in 1200 consecutive CLI patients in 27 vascular centers in Germany. The recruitment started in January 2013 and was completed in September 2014. Treatment options were endovascular revascularization (642, 53.5%), bypass surgery (284, 23.7%), femoral artery patchplasty (126, 10.5%) with or without concomitant peripheral intervention, conservative treatment (118, 9.8%), and primary major amputation (30, 2.5%). The primary endpoint of this study was amputation-free survival (AFS). The Society of Vascular Surgery’s suggested objective performance goal (OPG) for AFS (71%) was used as the effectiveness criterion. Multivariable regression methods were employed to identify variables that influenced the treatment selection and AFS after each treatment; results are presented as the hazard ratio (HR) and 95% confidence interval (CI). Results: The 12-month AFS estimates following endovascular therapy, bypass grafting, femoral patchplasty, and conservative treatment were 75%, 72%, 73%, and 72%, respectively. Factors influencing treatment choice were age, chronic kidney disease (CKD), diabetes, smoking, prior vascular procedures in the index leg, TransAtlantic Inter-Society Consensus II C/D lesions, and absence of runoff vessels. Cox regression analysis identified CKD (HR 2.07, 95% CI 1.26 to 3.41, p=0.004), the use of a prosthetic bypass conduit (HR 1.97, 95% CI 1.23 to 3.14, p=0.004), and previous vascular intervention in the index limb (HR 1.52, 95% CI 0.94 to 2.43, p=0.085) as independent risk factors for diminished AFS after bypass surgery. CKD (HR 1.47, 95% CI 1.09 to 1.99, p=0.012) and Rutherford category 6 (HR 1.81, 95% CI 1.30 to 2.52, p<0.001) compromised the performance of endovascular revascularization. Conclusion: CRITISCH registry data revealed that all first-line treatment strategies selected and indicated by the treating physicians met the suggested OPGs. CKD was an important determinant of patient prognosis after treatment regardless of the revascularization method.

Distal vein patch use and limb events after infragenicular prosthetic bypasses

ObjectiveIn the absence of suitable autologous vein, the use of prosthetic grafts for infragenicular bypasses in peripheral arterial disease has become standard practice. The purpose of this study was to investigate whether creating a vein patch at the distal anastomosis would further improve patency and freedom from major adverse limb events (MALEs). Furthermore, we sought to investigate whether the use of a distal vein patch (DVP) was associated with lower rates of acute limb ischemia (ALI) for those presenting with occluded prosthetic bypass graft. MethodsThe cases of all patients undergoing infragenicular prosthetic bypass grafts between January 2009 and July 2016 were retrospectively reviewed. Demographics of the patients, clinical data, and outcomes (graft patency and MALEs) were collected. Patients were compared according to treatment group (DVP vs no DVP). A Cox regression analysis was used to analyze follow-up results. ResultsDuring the study period, a total of 373 patients underwent infragenicular bypass at our institution; of those, 93 (24.9%) had prosthetic grafts (DVP, 39; no DVP, 54). Overall, 92 (98.9%) patients were male; the mean age was 63.3 ± 6.6 years and did not differ between the two groups. Patients undergoing prosthetic bypass with DVP were more likely to have chronic obstructive pulmonary disease (38.5% vs 14.8%; P = .009) and less likely to have chronic kidney disease (2.6% vs 20.4%; P = .011). Follow-up data were available for all patients for a median of 7.8 months (range, 1-89 months). After adjustment for differences in demographics and clinical data between the two groups, when outcomes were analyzed, MALEs were significantly lower in the DVP group (35.9% vs 57.4%; odds ratio [OR], 0.4; 95% confidence interval [CI], 0.2-0.9; P = .041). Similarly, reintervention rates were significantly lower in the DVP group (30.8% vs 50.0%; OR, 0.4; 95% CI, 0.2-0.9; P = .044). There was a trend toward higher primary patency in the DVP group (46.2% vs 35.2%; OR, 1.5; 95% CI, 0.7-3.5; P = .206) and lower rates of ALI after bypass occlusion (30.0% vs 42.9%; OR, 0.6; 95% CI, 0.2-1.8; P = .345). A Cox regression time-to-event analysis revealed late separation of freedom from MALEs for DVP relative to no DVP (log rank, P = .269). ConclusionsIn this evaluation of infragenicular prosthetic bypass grafts, the creation of a vein patch at the distal anastomosis was associated with lower reintervention rates and a trend toward improved primary patency and MALEs. Furthermore, for those presenting with occluded prosthetic bypass graft, the use of a DVP was associated with a trend toward lower rates of ALI.

A patient with lower gastrointestinal bleeding: common history, very uncommon cause, minimally invasive treatment

An 81-year-old patient with significant cardiac comorbidities, a history of sigmoid resection 6 years ago, and iliac bypass surgery 19 years ago presented with mild hematochezia for the previous 3 days. While hemodynamically stable at first, he developed massive bleeding during preparation for colonoscopy and underwent a short course of cardiopulmonary resuscitation. Colonoscopy revealed no active bleeding but a protuberance of the colonic wall and a coagulation clot. In ultrasonography immediately after endoscopy, a large aneurysm was diagnosed and diagnosis of an iliaco-colonic fistula was assumed. CT scan demonstrated a large pseudoaneurysm of the distal anastomosis after iliaco-iliac bypass. With endovascular treatment, the original lumen of the iliac artery could be recanalized, and 2 covered stents were placed to cover both anastomosis of the prosthetic bypass leading to a complete shutdown of bypass perfusion. A double-barreled transversostoma was established to minimize contamination of the aneurysmal sac. Seven months after these procedures, the patient is well and free of infection.Though aorto- or iliaco-colonic fistula after aortic or iliac surgery are very rare, endoscopists should be aware of their possibility. A high index of clinical suspicion in patients with prior abdominal vascular bypass surgery should prompt rapid imaging studies, possibly before endoscopy. In critically ill patients, endovascular treatment may be a suitable alternative and result in a favorable outcome.

Tissue expander-stimulated lengthening of arteries for the treatment of midaortic syndrome in children

BackgroundMidaortic syndrome (MAS) is a rare condition characterized by stenosis of the abdominal aorta. Patients with disease refractory to medical management will usually require either endovascular therapy or surgery with use of prosthetic graft material for bypass or patch angioplasty. We report our early experience with a novel approach using a tissue expander (TE) to lengthen the normal native arteries in children with MAS, allowing primary aortic repair without the need for prosthetic graft material. MethodsWe conducted a retrospective review of patients with MAS undergoing the TE-stimulated lengthening of arteries (TESLA) procedure at our institution from 2010 to 2014. Data are presented as mean (range). ResultsFive patients aged 4.8 years (3-8 years) underwent the TESLA procedure. Stages of this procedure include the following: stage I, insertion of retroaortic TE; stage II, serial TE injections; and stage III, final repair with excision of aortic stenosis and primary end-to-end aortic anastomosis. Stage II was completed in 4 months (1-9 months) with 12 (7-20) TE injections. Goal lengthening was achieved in all patients. Stage III could not be completed in one patient because of extreme aortic inflammation, which precluded safe excision of the aortic stenosis and required use of a prosthetic bypass graft. The other four patients completed stage III with two (one to three) additional vessels also requiring reconstruction (renal or mesenteric arteries). At 3.2 years (1-6 years) of follow-up, all patients are doing well. ConclusionsThe TESLA procedure allows surgical correction of MAS without the need for prosthetic grafts in young children who are still growing.

Nonconventional mesocaval prosthetic shunt interposition in refractory case with portal hypertension in a 10-kg female infant

Surgical treatment of portal hypertension in infants is challenging because of the high risk of shunt thrombosis. A 10-kg female infant underwent six failed procedures before being successfully treated by interposition of a 10-mm-diameter prosthetic graft between two 3-mm-diameter splanchnic veins and the inferior vena cava. Follow-up at 10 years demonstrates shunt patency and normal development without rebleeding. An aggressive surgical strategy is justified as long as even nonconventional techniques are available to prevent life-threatening complications of portal hypertension. Prosthetic grafts can be used when no autologous vein graft is available. Decellularized allografts with reduced immunogenicity may also be effective alternative materials. Keywords: mesocaval anastomosis, PHT, prosthetic shunt

Hospital Costs Associated With Dedicated Vascular Endoprosthesis Versus Prosthetic Bypass In Popliteal Artery Aneurysm Treatment In France

To assess hospital costs of patients with popliteal artery aneurysm (PAA) treated by dedicated vascular endoprosthesis versus prosthetic bypass. All hospital stays with PAA treated by endoprosthesis and prosthetic bypass were extracted from the French medical information system (Programme de Médicalisation des Systèmes d’Information, PMSI) 2013 database: implant code was used for endoprosthesis and the combination of both procedure and implant codes for prosthetic bypass. Patients were followed during one year from their first stay (March 2013/March 2014). An algorithm and a medical review excluded rehospitalisations not related to follow up for either treatment. To control confounding factors, patients from both arms were matched according to their age, gender, hospital status (public/private) and principal diagnosis ICD-10 (International Classification of Diseases) code. Associated costs during this period were added up both for the initial surgery and the related rehospitalisations: the mean 1-year cost per patient was estimated and compared between both arms. Valuation was performed considering French official tariffs. In 2013, 573 patients with endoprosthesis and 3,976 patients with prosthetic bypass were identified: 456 patients in each arm could be matched. Patients were 72±10 years old on average, 89% were men. 54% of stays occurred in public hospitals. Median length of initial stay was 3 days [2-6] for endoprosthesis implantation and 8 days [6-13] for prosthetic bypass surgery. 42% of endoprosthetic patients and 41% of bypass patients had at least one rehospitalization: respectively, 72% versus 74% of them occurred within 6 months after treatment. The mean 1-year cost was €12,714 ± €9,486 per endoprosthesis patient versus €14,038 ± €11,021 per bypass patient (difference statistically significant; p=0.0014). Using endoprosthesis instead of prosthetic bypass for the treatment of PAA led to a lower mean 1-year cost per patient.

Risk Factors and Outcomes Associated With Infected Lower Extremity Prosthetic Bypasses and Patches

Risk Factors and Outcomes Associated With Infected Lower Extremity Prosthetic Bypasses and Patches

Anticoagulation and antiplatelet therapy in patients with peripheral arterial disease of the femoropopliteal arteries.

Peripheral arterial disease (PAD) is associated with a substantial cardiovascular risk and secondary prevention is recommended for all patients. In this report, the literature on anticoagulant and antiplatelet drugs for patients with PAD in the femoro-popliteal segment is reviewed. PubMed/MEDLINE and Cochrane Database was searched for studies published between January 1966 and August 2017. Meta-analyses and randomized controlled trials describing outcome of anticoagulants or antiplatelet drugs for secondary prevention or following vascular interventions in patients with PAD were included. All patients with PAD should receive antiplatelet therapy to reduce cardiovascular risk with a slight preference for clopidogrel monotherapy. Following intervention, most patients will continue to benefit from this treatment. Patients receiving a venous bypass graft will benefit from VKA treatment and those with a below-knee prosthetic bypass graft should receive dual antiplatelet therapy (acetylsalicylic acid combined with clopidogrel). Further sufficiently powered studies are needed to further explore the optimal medical treatment for patients that undergo vascular interventions.

Infrarenal aorta as the donor site for bypasses to the superior mesenteric artery for chronic mesenteric ischemia: A prospective clinical series of 24 patients

Treatment of symptomatic, chronic mesenteric ischemia is indicated to relieve symptoms and prevent acute ischemia and death. Current therapeutic options include endovascular and open surgery. The purpose of this prospective study was to evaluate the results of bypasses to the superior mesenteric artery arising from the infrarenal aorta or infrarenal aortic grafts. From January 1999 to December 2016, 24 consecutive patients with a mean age of 61years underwent a prosthetic bypass to the superior mesenteric artery. Nine patients (37%) presented with an associated clinically important stenosis of the celiac artery and 10 (42%) of the inferior mesenteric artery. Five patients (21%) received preoperative parenteral nutrition. Four patients (17%) underwent dual antiplatelet treatment. The donor site was the infrarenal aorta in 19 patients (79%) and an infrarenal, Dacron graft was used in 5 (21%). The origin of the bypass was from the distal infrarenal aorta or Dacron graft in 19 patients (79%) and from the proximal infrarenal aorta in 5 patients (21%). The graft material consisted of 7mm polytetrafluoroethylene in 19 cases (79%) and 7mm Dacron in 5 cases (21%). A concomitant bypass to the inferior mesenteric artery was performed in 4 patients (17%). The primary end points were postoperative mortality, morbidity, graft infection, late survival, primary patency, and symptom-free rate. The secondary end point was postoperative hemorrhagic complications. No postoperative mortality occurred. Postoperative morbidity included a prolonged postoperative ileus in 4 patients (17%), transitory postoperative increases in serum creatinine concentrations in 3 patients (12%), and myocardial ischemia in 2 patients (8%). No postoperative hemorrhagic complications or graft infection were observed. Overall, the cumulative survival rate was 77% at 60months. The overall late-patency rate and freedom from recurrence of symptoms were both 87% at 60months. Infrarenal aorta and infrarenal aortic grafts are an excellent source for the revascularization of the superior mesenteric artery. Bypasses to the superior mesenteric artery from the infrarenal aorta, either isolated or associated with adjunctive bypass to the inferior mesenteric artery, yield results that are comparable with those obtained with complete digestive artery revascularization using other donor sources.

USE of arterialized saphenous vein venous flow-through flaps as a temporizing measure for hand salvage in contaminated wounds presenting with limb ischemia: A case series.

Vascular injuries resulting in limb ischemia are traditionally treated acutely with autologous or prosthetic bypass grafts. Traumatic contaminated injuries with soft tissue and vascular segmental loss are challenging as prosthetic bypasses are at risk of erosion, infection, and occlusion; and autologous bypasses are at risk of desiccation, blow-out, infection, and clotting. We propose a novel approach to these injuries by using arterialized saphenous vein venous flow-through free flaps (S-VFTF) as an autologous bypass, and present the results of its application in a series of cases. Spanning 2008 to 2015, four patients presenting with large contaminated crush/avulsion wounds with vascular injury underwent hand revascularization with S-VFTF, allowing the contaminated wounds to be serially debrided. Definitive soft tissue reconstruction was performed once the wound was considered clean. The S-VFTF skin paddle was de-epithelialized and the soft tissue defect covered with a free latissimus dorsi flap or a rectus abdominis myocutaneous flap. All ischemic limbs were successfully reperfused and there were no take backs for perfusion issues. All S-VFTF remained patent at discharge and final follow-up. No partial or complete finger/hand amputations were required. All definitive coverage free flap survived with no complications. The two-stage reconstruction presented may help reconstructive and vascular surgeons consider alternatives to traditional vascular reconstruction methods. This technique avoids an exposed vascular graft in an extensively contaminated open wound. It allows the surgeon to perform thorough and sufficient debridement of the wound, preventing definitive reconstruction in a not yet declared zone of injury.

Novel approach in using ultrasound in treating acute limb ischemia.

It is imperative to gain safe access into the occluded targeted vessel and begin treating acute extremity limb ischemia. Often the origin of the targeted native artery or bypass graft will have a flush occlusion making it difficult to cannulate. This paper looks at the novel use of portable ultrasound to evaluate the origin of the artery or bypass graft to help facilitate the start of thrombolysis. We reviewed our last 2 years of acute limb ischemia in our patients with high risk factors and comorbidities. We reviewed the use of ultrasound in these cases from the initial use of gaining femoral access to real time ultrasound and fluoroscopic guidance into the targeted native artery or bypass graft to begin needed thrombolysis. We had 26 acute limb ischemia in 10 patients with native arterial circulation and in 16 patients with either saphenous or prosthetic bypass grafts. Ultrasound was used in gaining safe access with no complications in 22 contralateral and 2 antegrade femoral and 4 direct-graft accesses. Ultrasound was used in 6 of these cases to help gain access in the occluded graft (4 cases) and saphenous veins (2 cases). It was successful in all cases but one case which had bleeding. Ultrasound is increasing in its application including acute limb ischemia with flush occlusions of native arteries and bypass grafts.

Invited commentary

The search for the optimal arterial replacement has continued for decades. The avenues of focus have been on material, technique, and medical adjuncts. Simultaneously, the role of interventions to salvage failing grafts has been dominated by duplex ultrasound surveillance. Duplex surveillance has been driven by the idea that demonstrable changes in hemodynamics corresponding with impending graft failure can be detected and treated before graft thrombosis. Surveillance has suffered from the determination of the best intervals, and the role of surveillance of prosthetic grafts has not been as well-demonstrated as for vein grafts. Enter the authors of the current manuscript. In this paper, the authors have taken another tack to optimize graft performance—a self-monitoring graft. Grafts previously lost in the interval between scheduled surveillance may now be saved with real-time continuous in vivo monitoring. This, the authors hope, can improve outcomes with prosthetic grafts until the holy grail of a perfect arterial substitute is attained. This paper offers a proof-of-concept study demonstrating a self-monitoring prosthetic bypass graft. The authors have developed a piezo-electric sensor that can be implanted surrounding a polytetrafluoroethylene graft. This sensor can then remotely deliver information regarding flow dynamics in the graft in real time via Blue Tooth technology. This is accomplished using proprietary parameters based on the acoustic energy present in the system. The current manuscript demonstrates early in vitro testing as well as in vivo results in an ovine carotid-carotid bypass model with follow-up to 30 days. The sensor covers 2 cm of the 20-cm graft and was able to detect upstream and downstream stenoses in vitro. The in vivo testing demonstrated that the data can be easily collected on a daily basis through living tissue. However, the in vivo testing did not provide any information on detection of stenoses (likely owing to the short time frame). This technology is exciting and has been ushered forward by the miniaturization that has been possible over the past two decades as well as the development of the Internet and wireless devices. This opens entirely new doors of investigation. Whether this new technology can be adapted to vein grafts as well as prosthetics; and whether any of this can actually lead to improved overall graft patency and clinical outcomes awaits further studies, which will likely be years in coming. As technology has improved so many other aspects of our daily lives, this report will undoubtedly usher in further avenues of study merging technology with graft materials development in an exciting way. Initial in vitro and in vivo evaluation of a self-monitoring prosthetic bypass graftJournal of Vascular SurgeryVol. 65Issue 6PreviewProsthetic grafts used for lower extremity revascularization and dialysis access fail because of hyperplastic stenosis and thrombosis. Graft surveillance is advocated to monitor function; however, graft failure can occur between episodic examinations. An innovative sensor with wireless, microchip technology allows automated surveillance with assessment of graft function using a “cloud”-based algorithm. We performed proof-of-concept experiments with in vitro and in vivo models to assess the feasibility such a real-time graft surveillance system. Full-Text PDF Open Archive

VESS20. Distal Vein Patch Use and Limb Events Following Infragenicular Prosthetic Bypasses

VESS20. Distal Vein Patch Use and Limb Events Following Infragenicular Prosthetic Bypasses

The Natural History and Outcomes of Endovascular Therapy for Claudication

The natural history of claudication is well-characterized and traditional therapy includes risk factor modification and exercise protocols with revascularization reserved for patients who are severely impaired. However, the reduced periprocedural morbidity with endovascular therapy has led physicians to broaden the indications for intervention for peripheral artery disease, and more claudicants are undergoing procedures for disease that is moderately limiting to their lifestyle. This study sought to assess the natural history of patients who have undergone peripheral vascular intervention for claudication. All patients who underwent at least 1 peripheral vascular intervention (PVI) for claudication at a single institution from January 2007 to December 2013 were identified. Patient demographics were assessed using the hospital record. Outcomes included secondary endovascular intervention, secondary bypass intervention, amputation, and survival. Cox proportional hazards models were created to assess risk factors for further intervention. Five hundred fifteen patients were identified as having undergone PVI for claudication during the study period. Forty-three percent were female, 37% had diabetes, 31% had coronary artery disease, 26% were current smokers, 6.6% had congestive heart failure, 8.2% had a tibial lesion that was intervened upon, and 35% had a Trans-Atlantic Inter-Society Consensus Document (TASC) II C/D lesion. Actuarial survival at 5years was 79.9% and 62.5% of patients had primary patency. The limb salvage rate was 97.2%. Over the follow-up period, 21.8% required some type of further intervention: either endovascular (17.7%) or open bypass (7.2%). A Cox proportional hazards model adjusting for age, sex, and other comorbidities showed that the two largest risk factors for requiring reintervention were angioplasty only (no stent; hazard ratio [HR] 1.36, P=0.02) and TASC C/D lesion (HR 1.52, P=0.03). With 5-year follow-up, patients have a primary patency that is comparable to an open prosthetic bypass to an above knee target. In addition, the secondary patency rate was over 90% and the major amputation rate as less than 3%. The presence of a TASC C/D lesion was predictive of failure of endovascular therapy, and surgical bypass should be considered in these patients.

Comparative effectiveness of anticoagulation on midterm infrainguinal bypass graft patency

ObjectiveTherapeutic anticoagulation (AC) is used clinically for prolongation of infrainguinal bypass patency, but evidence for the efficacy of this practice is conflicting. The objective of our study was to determine the association of AC with bypass graft primary patency. MethodsClinical and comorbid data of patients undergoing infrainguinal bypass grafts to a below-knee target with at least 1 year of follow-up performed from 2003 to 2015 were obtained from the Society for Vascular Surgery Vascular Quality Initiative. Inverse propensity of treatment-weighted Cox regression was used to assess the effect of AC on patency in the total cohort while adjusting for clinical, operative, and comorbid differences between treatment groups. Subgroup analyses of distal targets and conduit type were performed. Perioperative complications were analyzed using propensity-weighted logistic regression. ResultsWe identified 7612 bypass grafts with intact 1-year follow-up information from 2003 to 2015. The mean age was 67.5 ± 11.2 years; 30.5% (n = 2320) were female, and 28.6% (n = 2165) were discharged on therapeutic AC. The anticoagulated group had a higher rate of tibial, ankle, and pedal targets (52.1% [n = 1127] vs 47.6% [n = 2269]; P < .001), had a greater use of non-single-segment vein conduits (44.3% [n = 951] vs 26.5% [n = 1426]; P < .001), and was more likely to have had a previous ipsilateral bypass (27.2% [n = 589] vs 14.7% [n = 794]; P < .001) or stent (25.4% [n = 550] vs 20.9% [n = 1130]; P < .001). Estimated unadjusted primary patency was 70.8% ± 0.6% at 1 year and lower for anticoagulated bypasses (66.9% ± 1.2% vs 72.4% ± 0.7%; P < .001). Propensity-weighted analysis showed no significant association of AC with primary patency in the overall cohort (hazard ratio [HR], 0.98; 95% confidence interval [CI], 0.86-1.11; P = .8) but demonstrated a trend toward improvement of primary patency in those with a non-single-segment vein conduit to a below-knee popliteal target (HR, 0.85; 95% CI, 0.80-1.02; P = .09). AC was associated with significantly improved secondary patency in those with prosthetic bypass grafts (HR, 0.77; 95% CI, 0.62-0.96; P = .02) or prosthetic bypasses to an infrapopliteal target (HR, 0.72; 95% CI, 0.54-0.97; P = .02). Odds of postoperative wound complications were significantly higher in those receiving AC (odds ratio, 1.33; 95% CI, 1.11-1.61; P = .002). ConclusionsThis study does not demonstrate a significant impact of therapeutic AC on primary patency for infrainguinal bypass grafts. Treatment with AC may benefit secondary patency in those with a prosthetic bypass, especially to an infrapopliteal target, but at an increased risk of postoperative wound complications.

Hybrid Endovascular Aortic Aneurysm Repair: Preservation of Pelvic Perfusion with External to Internal Iliac Artery Bypass

Diminished pelvic arterial flow as a result of intentional coverage/embolization of internal iliac arteries (IIA) during isolated endovascular common iliac artery aneurysm (CIAA) repair or endovascular repair of abdominal aortic aneurysms (EVAR) may result in symptomatic pelvic ischemia. Although generally well tolerated, in severe cases, pelvic ischemia may manifest as recalcitrant buttock claudication, vasculogenic impotence, or perineal, vesicle, rectal, and/or spinal cord ischemia. Branched graft technology has recently become available; however, many patients are not candidates for endovascular repair with these devices. Therefore, techniques to preserve pelvic arterial flow are needed. We reviewed our outcomes of isolated endovascular CIAA repair or EVAR in conjunction with unilateral external-internal iliac artery bypass. Single-center, retrospective review of 10 consecutive patients who underwent hybrid endovascular abdominal aortic aneurysm (AAA) or CIAA repair with concomitant external-internal iliac artery bypass between 2006 and 2015. Demographics, index procedural details, postoperative symptoms, hospital length of stay (LOS), follow-up imaging, and bypass patency were recorded. The cohort of 10 patients was all men with a mean age of 71years (range: 56-84). Hybrid repair consisted of contralateral IIA coil embolization followed by EVAR with external iliac artery-internal iliac artery (EIA-IIA) bypass. All EIA-IIA bypasses were performed via a standard lower quadrant retroperitoneal approach with a prosthetic bypass graft. Technical success was 100%, and there were no perioperative deaths. One patient developed transient paraplegia, 1 patient had buttock claudication on the side of his hypogastric embolization contralateral to his iliac bypass, and 1 developed postoperative impotence. 20% of patients sustained long-term complications (buttock claudication and postoperative impotence). Mean LOS was 2.8days (range: 1-9days). Postoperative imaging was obtained in 90% of patients, and mean follow-up was 10.8months (range: 0.5-36months). All bypasses remained patent. Although branched graft technology continues to evolve, strategies to maintainadequate pelvic circulation are necessary to avoid the devastating complications of pelvic ischemia. We have demonstrated that a hybrid approach combining EVAR or isolated endovascular common iliac artery exclusion with a unilateral external-internal iliac bypass via a retroperitoneal approach is well tolerated with a short LOS and excellent patency rates.

Prosthetic bypass for restenosis after endarterectomy or stenting of the carotid artery

ObjectiveThe objective of this study was to evaluate the results of prosthetic carotid bypass (PCB) with polytetrafluoroethylene (PTFE) grafts as an alternative to carotid endarterectomy (CEA) in treatment of restenosis after CEA or carotid artery stenting (CAS). MethodsFrom January 2000 to December 2014, 66 patients (57 men and 9 women; mean age, 71 years) presenting with recurrent carotid artery stenosis ≥70% (North American Symptomatic Carotid Endarterectomy Trial [NASCET] criteria) were enrolled in a prospective study in three centers. The study was approved by an Institutional Review Board. Informed consent was obtained from all patients. During the same period, a total of 4321 CEAs were completed in the three centers. In these 66 patients, the primary treatment of the initial carotid artery stenosis was CEA in 57 patients (86%) and CAS in nine patients (14%). The median delay between primary and redo revascularization was 32 months. Carotid restenosis was symptomatic in 38 patients (58%) with transient ischemic attack (n = 20) or stroke (n = 18). In this series, all patients received statins; 28 patients (42%) received dual antiplatelet therapy, and 38 patients (58%) received single antiplatelet therapy. All PCBs were performed under general anesthesia. No shunt was used in this series. Nasal intubation to improve distal control of the internal carotid artery was performed in 33 patients (50%), including those with intrastent restenosis. A PTFE graft of 6 or 7 mm in diameter was used in 6 and 60 patients, respectively. Distal anastomosis was end to end in 22 patients and end to side with a clip distal to the atherosclerotic lesions in 44 patients. Completion angiography was performed in all cases. The patients were discharged under statin and antiplatelet treatment. After discharge, all of the patients underwent clinical and Doppler ultrasound follow-up every 6 months. Median length of follow-up was 5 years. ResultsNo patient died, sustained a stroke, or presented with a cervical hematoma during the postoperative period. One transient facial nerve palsy and two transient recurrent nerve palsies occurred. Two late strokes in relation to two PCB occlusions occurred at 2 years and 4 years; no other graft stenosis or infection was observed. At 5 years, overall actuarial survival was 81% ± 7%, and the actuarial stroke-free rate was 93% ± 2%. There were no fatal strokes. ConclusionsPCB with PTFE grafts is a safe and durable alternative to CEA in patients with carotid restenosis after CEA or CAS in situations in which CEA is deemed either hazardous or inadvisable.

Surface Coating of Polytetrafluoroethylene with Extracellular Matrix and Anti-CD34 Antibodies Facilitates Endothelialization and Inhibits Platelet Adhesion Under Sheer Stress.

Expanded polytetrafluoroethylene (ePTFE) polymers do not support endothelialization because of nonconductive characteristics towards cellular attachment. Inner surface modification of the grafts can improve endothelialization and increase the long-term patency rate of the ePTFE vascular grafts. Here we reported a method of inner-surface modification of ePTFE vascular graft with extracellular matrix (ECM) and CD34 monoclonal antibodies (CD34 mAb) to stimulate the adhesion and proliferation of circulating endothelial progenitor cells on ePTFE graft to enhance graft endothelialization. The inner surface of ECM-coated ePTFE grafts were linked with CD34 mAb in the presence of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide (EDC/NHS) solution and the physicochemical properties, surface morphology, biocompatibility, and hemocompatibility of the grafts were studied. The hydrophilicity of CD34 mAb-coated graft inner surface was significantly improved. Fourier transform infrared spectroscopy analysis confirmed ECM and CD34 mAb cross-linking in the ePTFE vascular grafts with our method. Scanning electron microscopy analysis showed protein layer covering uniformly on the inner surface of the modified grafts. The cell-counting kit-8 (CCK-8) assay confirmed that the modified graft has no obvious cytotoxicity. The modified graft showed a low hemolytic rate (0.9%) in the direct contact hemolysis test, suggesting the modification improved hemocompatibility of biopolymers. The modification also decreased adhesion of platelets, while significantly increased the adhesion of endothelial cells on the grafts. We conclude that our method enables ePTFE polymers modification with ECM and CD34 mAb, facilitates endothelialization, and inhibits platelet adhesion on the grafts, thus may increase the long-term patency rate of the prosthetic bypass grafts.