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

Endoscopic vein harvest and its effect on lower extremity arterial bypass patency

OBJECTIVE

The use of endoscopic vein harvest (EVH) vs open vein harvest (OVH) for lower extremity arterial bypass has been an area of continued interest. Previous studies have suggested wound complication rates are improved with EVH, but there has been concern for decreased patency of these grafts long term from possible damage with EVH techniques. This study aims to evaluate the effect of EVH and patency rates.

METHODS

This retrospective study evaluated 340 patients who underwent any infrainguinal bypass with continuous segment great saphenous vein from 2013 to 2023 with OVH (n = 111) vs EVH (n = 229). Demographics, harvest technique, incisional breakdown, and need for arterial procedure from 1 to 5 years were evaluated. Primary, primary assisted, and secondary patency rates were evaluated.

RESULTS

The average age was 62.6 ± 8.8 years, and the majority of individuals were male (71.5%). The majority of participants were White (88.8%), current smokers (52.2%), had hypertension (78.0%), and the average body mass index was 27.9 ± 6.0 kg/m2. Of these, 254 (75%) had below-knee outflow targets, and 86 (25%) had above-knee outflow targets. Mean operative time was 193 minutes for EVH and was 228 minutes for OVH (P = .03). Hospital length of stay was similar between the groups. Primary patency rates including above- and below-knee targets were 43.8% EVH vs 49.6% OVH (P = .43), primary-assisted patency of 89.0% EVH vs 91.0% OVH (P = .52), and secondary patency of 81% EVH vs 75.0% EVH (P = .35). Patients with EVH were less likely to have incision breakdown compared with OVH (11.9% vs 21.1%; P = .04). A logistic regression model showed that EVH had a lower odds of failure of initial bypass requiring new bypass creation compared with OVH (adjusted odds ratio, 0.66; 95% confidence interval, 0.33-0.99). Additionally, there was also a reduction in the odds of wound complications and need for amputation with EVH vs OVH.

CONCLUSIONS

This study found no significant difference in primary, primary-assisted, and secondary patency rates when comparing EVH with OVH. The benefits of decreased operative time, similar patency rates, and decreased wound complications is promising. When EVH is performed by experienced providers, this technique could be considered for vein harvest, but future studies are needed to better evaluate its long-term efficacy.

Six-Month Patency of Long Carotid Bypass Grafts Constructed with In-Body Tissue Architecture-Induced Small-Diameter Biotubes in a Goat Model

This study investigated the long-term patency of regenerative Biotube grafts and discusses their feasibility as an alternative to autologous vein grafts for peripheral artery disease. Six Biotubes with a diameter of 4 mm were autologously fabricated in recipients using in vivo tissue engineering (in-body tissue architecture) technology and implanted as carotid artery bypass grafts in a goat model. All six grafts remained patent at 6 months despite exceeding 10 cm in length, demonstrating their biocompatibility and durability. Histological analysis revealed neointima formation, endothelialization, and minimal inflammation. However, in one goat, a graft developed stenosis, while another showed dilatation. These findings demonstrate the use of Biotubes as a viable option for peripheral vascular reconstruction as tissue-engineered vascular grafts. However, further optimization is needed to address emerging issues with their use, such as stenosis and aneurysm formation, to improve long-term patency.

Long-term outcomes of below-the-knee bypass surgery using heparin-bonded expanded polytetrafluoroethylene grafts

PURPOSE

To report the outcomes of below-the-knee (BK) bypass surgery using heparin-bonded expanded polytetrafluoroethylene (ePTFE) grafts, performed in two centers since its launch in Japan.

METHODS

We conducted a retrospective analysis of databases from two medical centers, evaluating 51 limbs in 42 consecutive patients with peripheral arterial disease (PAD), who underwent BK bypass surgery using heparin-bonded ePTFE grafts between October, 2013 and April, 2023.

RESULTS

Thirty-three limbs (64.7%) were classified as Rutherford category 4-6 and 33 limbs (64.7%) had a history of ipsilateral revascularization. Technical success was achieved in 98% of the patients. The 30 day mortality rate was 2.4% (n = 1) and the overall 30 day complication rate was 9.5% (n = 4). The median follow-up period was 38 (interquartile range 13-67) months. Three patients required major amputation and 14 died during follow-up. Primary patency rates at 1, 3, and 5 years were 67.8%, 57.5%, and 46.5%, respectively, while secondary patency rates for these periods were 84.6%, 70.0%, and 66.0%, respectively. Overall survival rates at 1, 3, and 5 years were 90.1%, 74.5%, and 70.9%, respectively.

CONCLUSIONS

BK bypass surgery using heparin-bonded ePTFE graft is a viable and durable option for patients with PAD, who are deemed unsuitable for autologous vein bypass surgery.

Endovascular and Hybrid Interventions for Aortoiliac Occlusive Disease in Patients with Intermittent Claudication

BACKGROUND

Significant practice variability exists regarding the management of intermittent claudication (IC) across anatomic segments. We sought to answer the question of whether the safety, efficacy, and durability outcomes of an endovascular approach with or without common femoral endarterectomy for complex aortoiliac occlusive disease (AIOD) justify a surgical approach in patients presenting with IC.

METHODS

A retrospective single-center review of all patients who were treated using an endovascular approach for AIOD with or without common femoral artery endarterectomy (CFE) from 2010 to 2020 was conducted. The review was limited to those with symptoms of IC. Patient- and limb-level preoperative presentations were reviewed. The outcomes were postoperative complications and patency rates in addition to freedom from re-intervention. Subgroup analyses were conducted to compare patients who underwent endovascular and hybrid procedures.

RESULTS

A total of 245 limbs in 180 consecutive patients were analyzed. The mean age was 65 years, and 61% were males. Of 176 patients, 101 (57%) had trans-atlantic inter-society consensus (TASC) class D and 18 (10%) had class C. Eleven limbs (7.4%) had access site complications, 12 (7.9%) had surgical wound complications, and below-the-knee amputation was observed in 2 limbs (0.82%) (2 patients). Two (1.0%) patients had perioperative myocardial infarction (MI), 1 (0.5%) stroke, 1 (0.5%) AKI that progressed to dialysis, and no 30-day mortality. Rutherford's classification was improved during the follow-up period. The 1-, 2-, and 5-year primary patency rates were 94%, 77%, and 58%; primary-assisted patency rates were 98%, 91%, and 79%, respectively; and secondary patency rates were 100% for all follow-up periods. Patients who had concurrent CFE were likely to have hypertension, hyperlipidemia, and anatomically more diffuse disease. No significant differences in patency or reintervention-free survival were observed, though event rates were low in both outcomes and trended toward a protective effect with CFE.

CONCLUSIONS

Endovascular management for complex AIOD with or without CFE for IC patients is safe, effective, and durable. These results justify an active, patient-centered approach for this advanced anatomic disease pattern. The morbidity of a hybrid approach in the CFE subset is low, and treatment vessel patency is excellent. The presence of anatomically advanced AIOD is not prohibitive for the treatment of patients with IC; however, careful patient selection is essential.

Drug-Coated Balloons in Autologous Vein Peripheral-Distal Bypass Graft Maintenance: Advancements and Potential Impact

INTRODUCTION

Initial surgical revascularization has a recognized primary role in patients with critical limb-threatening ischemia with a high-quality great saphenous vein for conduit. However, approximately one-third of lower extremity vein grafts develop lesions threatening graft patency. Traditional treatments have limitations, highlighting the need for innovative solutions. The advantage of drug-coated balloons (DCBs) in treating native femoropopliteal occlusive disease is well established for its anti-restenotic features. This study evaluates the use of DCBs in maintaining the patency of autologous vein infrainguinal bypass grafts.

METHODS

This retrospective multicenter cohort study included consecutive patients who underwent DCB angioplasty of infrainguinal bypass vein graft stenoses from January 2010 to December 2022 in 4 tertiary Vascular Surgery referral Centers. The primary endpoints were assisted primary patency rate, amputation, and death. All endpoints were assessed at baseline, at 1, 3, and 6 months, and every 6 months after the procedure. Follow-up was mainly performed via duplex ultrasound, by hand of an experienced independent operator.

RESULTS

In total, 296 patients received an endovascular procedure for primary patency loss of a pre-existing infrainguinal saphenous vein bypass graft. Of these, 86 cases (29%) were treated with a paclitaxel-coated balloon. The mean age of patients was 72 (67-75) years, most being males (62%, n=53). The median time from the primary revascularization to reintervention with DCB was 2.58 (95% confidence interval [CI]: 2.31-3.10) years. The DCB angioplasty involved the proximal anastomosis in 20%, the graft in 51%, the distal anastomosis in 33%, and the outflow region in 28% of cases. During a median follow-up of 5 years (3.93-7.01), a 69% assisted primary patency rate was recorded. Limb salvage was achieved in 100% of cases at 1 year and in 90% of cases at 3 years. Only 6 cases of major amputation were recorded in a median follow-up time of 10 years. Overall survival reached 84% at 5 years, calculated on a median follow-up of 9.4 (95% CI: 8.7-10.1) years.

CONCLUSION

Results suggest that DCBs may have a transformative impact on vascular care, reducing the need for repeated reinterventions, and thus improving the quality of life for patients with peripheral bypass grafts.

CLINICAL IMPACT

This study proposes a groundbreaking shift in the management of lower extremity vein graft lesions. By demonstrating the efficacy of drug-coated balloons (DCBs) in maintaining patency of infrainguinal vein bypass grafts, it offers clinicians a novel strategy to address a significant clinical challenge. Unlike traditional treatments with their limitations, DCBs present a promising alternative, potentially reducing the burden of repeated reinterventions. This innovation signifies a tangible improvement in patient outcomes, promising enhanced limb salvage rates and overall survival, thereby revolutionizing vascular care and enhancing the quality of life for individuals with peripheral bypass grafts.

Distal Adjuncts for High-Risk Lower Extremity Bypasses

BACKGROUND

This review will discuss the use of distal adjuncts for improving graft patency in high-risk lower extremity bypasses.

METHODS

Factors that contribute to the increased risk of failure in high-risk lower extremity bypasses, such as the use of nonautogenous conduits, the creation of bypasses to very distal arterial targets, and bypasses in patients with significant tibial arterial disease, will be discussed.

RESULTS

The use of surgical techniques such as creating venous cuffs, venous patches, and arteriovenous fistulas have been shown to improve the patency of high-risk bypasses.

CONCLUSIONS

Despite the increased risk of failure, the use of surgical adjuncts such as cuffs, patches, and arteriovenous fistulas can improve the patency rates of high-risk lower extremity bypasses.

Lower Extremity Bypass for Occlusive Disease: A Brief History

BACKGROUND

This is a narrative review that aims to highlight key advancements that led to the current state of lower extremity bypass surgery. It focuses on key contributors during the last century who have driven the standardization of surgical treatment of peripheral arterial occlusive disease.

METHODS

A narrative review was conducted utilizing available resources in the scientific and historical literature to track landmark achievements in the development of modern lower extremity bypass surgery for occlusive disease, focusing primarily on the last century of advancement.

RESULTS

Several critical conceptual, technological, and technical landmarks were identified as critical components of modern lower extremity bypass surgery. This includes fundamental developments in the techniques of vascular anastomosis led by Carrel and others, a developing understanding of vascular occlusive disease as a localized and segmental process with broad implementation of the techniques of arteriography, and the development of safe thromboendarterectomy aided by the development and utilization of heparin for anticoagulation. These factors led to the first femoral-to-popliteal artery bypass by Jean Kunlin in 1948. From here, advances in vascular prosthetic material pioneered by Voorhees and others, alternative vascular conduits, increasing acceptance of tibial revascularization, and dispelling the myth of diabetic "small vessel" disease broadened revascularization options for patients with complex patterns of occlusive disease and those who have limited conduit availability.

CONCLUSIONS

Modern lower extremity bypass surgery for occlusive disease arose steadily over a course of a century, driven by complex problem-solving in the pathophysiological understanding of atherosclerosis, technical developments in vascular anastomosis and arteriography, and evolution of conduit materials and pharmacologic therapy. Future advancements in bypass surgery are targeted at solving the complex problems of anastomotic intimal hyperplasia, expanding technology for alternative vascular conduits, ongoing optimization of risk factors, and scrutinizing of outcomes to make patient-centered, evidence-based decisions regarding revascularization strategy.

Surgery or Endovascular Therapy for Chronic Limb-Threatening Ischemia

Chronic limb-threatening ischemia is defined as ischemic rest pain or tissue loss (eg, ulceration/gangrene) that has been present for greater than 2 weeks. Workup includes a careful history, physical examination focused on evaluation of pulses and wounds, lower extremity noninvasive vascular studies (eg, ankle-brachial indices, toe pressures), saphenous vein mapping, and imaging of the lower extremity arterial anatomy (eg, computed tomography, magnetic resonance, or subtraction angiography) if a revascularization intervention is planned.

2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease" provides recommendations to guide clinicians in the treatment of patients with lower extremity peripheral artery disease across its multiple clinical presentation subsets (ie, asymptomatic, chronic symptomatic, chronic limb-threatening ischemia, and acute limb ischemia).

METHODS

A comprehensive literature search was conducted from October 2020 to June 2022, encompassing studies, reviews, and other evidence conducted on human subjects that was published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through May 2023 during the peer review process, were also considered by the writing committee and added to the evidence tables where appropriate.

STRUCTURE

Recommendations from the "2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with peripheral artery disease have been developed.

2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease" provides recommendations to guide clinicians in the treatment of patients with lower extremity peripheral artery disease across its multiple clinical presentation subsets (ie, asymptomatic, chronic symptomatic, chronic limb-threatening ischemia, and acute limb ischemia).

METHODS

A comprehensive literature search was conducted from October 2020 to June 2022, encompassing studies, reviews, and other evidence conducted on human subjects that was published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through May 2023 during the peer review process, were also considered by the writing committee and added to the evidence tables where appropriate.

STRUCTURE

Recommendations from the "2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with peripheral artery disease have been developed.

Overview and comparison of contemporary Society for Vascular Surgery, American Heart Association/American College of Cardiology, and European Society for Vascular Surgery guidelines for the management of patients with intermittent claudication

Intermittent claudication (IC) is a phenotype of peripheral artery disease that is characterized by pain in the lower extremity muscles during activity that is relieved by rest. Medical management, risk factor control, smoking cessation, and exercise therapy have historically been the mainstays of treatment for IC, but advances in endovascular technology have led to increasing use of peripheral vascular interventions in this patient population. There are meaningful differences in published society guidelines and appropriate use criteria relevant to the management of IC, especially regarding indications for peripheral vascular interventions. The current review aims to highlight similarities and differences between major society recommendations for the management of IC, and to discuss practice trends, disparities, and evidence gaps in the use of peripheral vascular interventions for IC in the context of existing guidelines.

Autologous and synthetic pediatric iliofemoral reconstruction: a novel technique for pediatric iliofemoral artery reconstruction

Pediatric lower extremity arterial catheterization-related injuries can result in significant long-term morbidity. Revascularization is challenging due to concerns for long-term patency and growth accommodation with synthetic grafts. We describe a novel technique for iliofemoral revascularization using common iliac artery transposition and bridging polytetrafluoroethylene grafts. We treated two children who underwent femoral catheterization resulting in lifestyle-limiting claudication. Both patients experienced immediate resolution of symptoms. Postoperative imaging demonstrated widely patent vasculature. ASPIRE (autologous and synthetic pediatric iliofemoral reconstruction) is a method of pediatric iliofemoral artery revascularization that allows for an autologous artery to span the hip joint, reducing graft thrombosis risk and accommodating patient growth.

Carotid Artery Bypass Surgery of In-Body Tissue Architecture-Induced Small-Diameter Biotube in a Goat Model: A Pilot Study

Biotubes are autologous tubular tissues developed within a patient's body through in-body tissue architecture, and they demonstrate high potential for early clinical application as a vascular replacement. In this pilot study, we used large animals to perform implantation experiments in preparation for preclinical testing of Biotube. The biological response after Biotube implantation was histologically evaluated. The designed Biotubes (length: 50 cm, internal diameter: 4 mm, and wall thickness: 0.85 mm) were obtained by embedding molds on the backs of six goats for a predetermined period (1-5 months). The same goats underwent bypass surgery on the carotid arteries using Biotubes (average length: 12 cm). After implantation, echocardiography was used to periodically monitor patency and blood flow velocity. The maximum observation period was 6 months, and tissue analysis was conducted after graft removal, including the anastomosis. All molds generated Biotubes that exceeded the tensile strength of normal goat carotid arteries, and eight randomly selected Biotubes were implanted. Thrombotic occlusion occurred immediately postoperatively (1 tube) if anticoagulation was insufficient, and two tubes, with insufficient Biotube strength (<5 N), were ruptured within a week. Five tubes maintained patency for >2 months without aneurysm formation. The spots far from the anastomosis became stenosed within 3 months (3 tubes) when Biotubes had a wide intensity distribution, but the shape of the remaining two tubes remained unchanged for 6 months. The entire length of the bypass region was walled with an αSMA-positive cell layer, and an endothelial cell layer covered most of the lumen at 2 months. Complete endothelial laying of the luminal surface was obtained at 3 months after implantation, and a vascular wall structure similar to that of native blood vessels was formed, which was maintained even at 6 months. The stenosis was indicated to be caused by fibrin adhesion on the luminal surface, migration of repair macrophages, and granulation formation due to the overproliferation of αSMA-positive fibroblasts. We revealed the importance of Biotubes that are homogeneous, demonstrate a tensile strength > 5 N, and are implanted under appropriate antithrombotic conditions to achieve long-term patency of Biotube. Further, we clarified the Biotube regeneration process and the mechanism of stenosis. Finally, we obtained the necessary conditions for a confirmatory implant study planned shortly.

Endovascular aneurysm repair with mesenteric artery bypass for abdominal aortic aneurysm with occlusion of celiac and superior mesenteric arteries

A 67-year-old male patient required surgical management of an abdominal aortic aneurysm. Contrast-enhanced computed tomography showed a saccular infrarenal abdominal aortic aneurysm and occlusion of the origins of the celiac artery, superior mesenteric artery, and inferior mesenteric artery. Aortography revealed large amounts of blood flow from capillaries around the abdominal aorta to the inferior mesenteric artery and retrograde blood flow to a meandering mesenteric artery through the superior rectal artery. Considering the risk of bowel ischemia, we performed endovascular aneurysm repair with mesenteric artery bypass. The operation was successful, and his postoperative course was uneventful. This procedure could be useful and less invasive.

Indications for a "Surgery-First" Approach for the Treatment of Lower Extremity Arterial Disease

BACKGROUND

In recent years, there has been a tendency toward an "endovascular-first" approach for the treatment for femoropopliteal arterial disease. The purpose of this study is to determine if there are patients that are better served with an initial femoropopliteal bypass (FPB) rather than an endovascular attempt at revascularization.

METHODS

A retrospective analysis of all patients undergoing FPB between June 2006 - December 2014 was performed. Our primary endpoint was primary graft patency, defined as patent using ultrasound or angiography without secondary intervention. Patients with <1-year follow-up were excluded. Univariate analysis of factors significant for 5-year patency was performed using χ2 tests for binary variables. A binary logistic regression analysis incorporating all factors identified as significant by univariate analysis was used to identify independent risk factors for 5-year patency. Event-free graft survival was evaluated using Kaplan-Meier models.

RESULTS

We identified 241 patients undergoing FPB on 272 limbs. FPB indication was disabling claudication in 95 limbs, chronic limb-threatening ischemia (CLTI) in 148, and popliteal aneurysm in 29. In total, 134 FPB were saphenous vein grafts (SVG), 126 were prosthetic grafts, 8 were arm vein grafts, and 4 were cadaveric/xenografts. There were 97 bypasses with primary patency at 5 or more years of follow-up. Grafts patent at 5 years by Kaplan-Meier analysis were more likely to have been performed for claudication or popliteal aneurysm (63% 5-year patency) as compared with CLTI (38%, P < 0.001). Statistically significant predictors (using log rank test) of patency over time were use of SVG (P = 0.015), surgical indication of claudication or popliteal aneurysm (P < 0.001), Caucasian race (P = 0.019) and no history of COPD (P = 0.026). Multivariable regression analysis confirmed these 4 factors as significant independent predictors of 5-year patency. Of note, there was no statistical correlation between FPB configuration (above or below knee anastomosis, in-situ versus reversed saphenous vein) and 5-year patency. There were 40 FPBs in Caucasian patients without a history of COPD receiving SVG for claudication or popliteal aneurysm that had a 92% estimated 5-year patency by Kaplan-Meier survival analysis.

CONCLUSIONS

Long-term primary patency that was substantial enough to consider open surgery as a first intervention was demonstrated in Caucasian patients without COPD, having good quality saphenous vein, and who underwent FPB for claudication or popliteal artery aneurysm.

Evaluation of Arterial and Venous Allografts in Subinguinal Bypasses

BACKGROUND

Autologous saphenous vein is the preferred conduit for below-the-knee bypasses in patients with critical limb-threatening ischemia. Alternative graft must be considered for patients without (autologous saphenous vein). The aim of this article is to evaluate the mid-term performance of arterial allograft (AA) and venous allograft (VA) used as alternative conduits.

METHODS

This retrospective study included patients with critical limb-threatening ischemia, with or without a history of homolateral femoropopliteal bypass, and no autologous veins were available who underwent infrainguinal arterial reconstructions using VA or AA from 2008 to 2018. Patients undergoing revision operations for infected bypasses were excluded. Primary patency (PP), primary assisted patency, secondary patency, major amputation, and death from any cause were the endpoints. For each event, a set of analyses were performed.

RESULTS

Overall, 111 patients (63 VAs and 48 AAs) were included, with 108 having below-the-knee bypass. The median follow-up time was 27.8 months (15.6-37.4). The difference in PP between the 2 allograft types was significant (P = 0.049), with 65.9% (43.7-81.0), 44.1% (24.2-62.3), and 44.1% (24.2-62.3) in the AA group, respectively, at 6, 12, and 18 months, whereas 55.6% (40.0-68.6), 46.0% (30.6-60.2), and 33.2% (18.2-49.0) in the VA group. The choice of an AA over a VA was an independent factor associated with patency (for PP: hazard ratio [HR] = 0.43 [0.24-0.75], P = 0.003); primary assisted patency: HR = 0.52 (0.30-0.89], P = 0.018; and secondary patency: HR = 0.49 (0.27-0.88), P = 0.016. The allograft type did not affect either the incidence of major amputation or death from any cause (respectively, HR = 1.20 [0.49-2.93], and 0.88 [0.37-2.14]).

CONCLUSIONS

The nature of the allograft appears to influence the patency of infrainguinal reconstruction, but not the course of the disease. Performant alternative grafts answering infectious issues are needed.

Ethnicity-based differences in thrombosis in lower extremity vascular bypass: a review of current literature

INTRODUCTION

Understanding prothrombotic factors is important in vascular surgery for surgical planning, preoperative evaluation, and post-operative management. The purpose of this study was to investigate ethnicity-based differences in coagulation between East Asian and Western cohorts by comparing patency rates after infrainguinal bypass surgery.

EVIDENCE ACQUISITION

A review of infrainguinal bypass patients was conducted for East Asian (including Chinese, Japanese, and Korean) and Western (North American and European) studies between 1990 and 2015 within the Journal of Vascular Surgery. The number of patent grafts at 1-year and 5-years were calculated from reported patency rates for PTFE grafts, Dacron grafts, all prosthetic grafts, autogenous grafts, and all grafts. Statistical analysis was performed using Chi-square test for each graft type at each time point.

EVIDENCE SYNTHESIS

A total of 9972 grafts from 50 studies were included in our review. There were 3592 grafts from East Asian patients and 6380 grafts from Western patients. There was a statistically significant (P<0.05) difference between East Asian and Western cohorts in both 1-year and 5-year patency rates for PTFE, all prosthetic, and all grafts.

CONCLUSIONS

East Asians had significantly higher patency rates after infrainguinal bypass surgery for PTFE, all prosthetic, and all graft types compared with Westerners, showing an ethnicity-based difference in thrombosis. Further research is needed to identify the specific genetic or dietary influences causing this significant difference.

What should we expect from intravascular ultrasound use for complex femoropopliteal lesions?

In this review article, we summarize the clinical benefit of intravascular ultrasounds (IVUS) in the endovascular therapy (EVT) of complex femoropopliteal (FP) lesions. Due to the development of novel FP-dedicated devices, outcomes of FP-EVT have been improved. As a result, revascularization methods for the FP lesions have shifted to EVT. However, the long-term durability in complex FP lesions has not yet reached that of bypass surgery using autogenous vein. Strategies for EVT of complex FP lesions are still inconsistent and have room for improvement. Long-term results generally depend on the patient and lesion backgrounds but are also affected by the quality of the procedure. Previous reports have shown IVUS evaluation can better assess vessel size compared to conventional angiographic evaluation. In contrast to angio-guided EVT, which evaluates vessel size by inner diameter, IVUS can be evaluated it with an external elastic membrane, which leads to the selection of a more appropriate (basically, larger) size device. Conversely, angiographic evaluation underestimates the vessel size, suggesting that it may lead to insufficient result. Furthermore, IVUS can also assess the adequate guidewire route, presence of severe dissection etc. As the evidence so far shows, the use of IVUS may improve the quality of EVT procedure, resulting in improved long-term outcomes. In conclusion, despite the widespread use of IVUS in FP-EVT practice, it still conditionally applied. The purpose of IVUS in the EVT of complex FP lesions should be clarified. More evidence regarding the IVUS in complex FP lesions is needed.

Saphenous vein dilation as an alternative to prosthetic femoral–distal bypass revascularization

A 63-year-old man with a history of bipolar and schizoaffective disorder was admitted to the psychiatry unit. His comorbidities included active smoking, hypertension, diabetes, hyperlipidemia, coronary artery disease after coronary artery bypass grafting, and peripheral arterial disease. During the admission, the patient began to complain of right foot pain at rest. Angiography revealed occlusion of a previously placed right superficial femoral artery and popliteal stents, severe common femoral and distal popliteal stenosis with only a patent posterior tibial (PT) artery runoff. Serial venoplasty was performed and revealed an inadequately sized, ipsilateral great saphenous vein, followed by a delayed femoral–PT in situ saphenous vein bypass. Angiography at 32 months demonstrated a patent femoral–PT great saphenous vein bypass.

Development of a vascular substitute produced by weaving yarn made from human amniotic membrane

Because synthetic vascular prostheses perform poorly in small-diameter revascularization, biological vascular substitutes are being developed as an alternative. Although their in vivo results are promising, their production involves long, complex, and expensive tissue engineering methods. To overcome these limitations, we propose an innovative approach that combines the human amniotic membrane (HAM), which is a widely available and cost-effective biological raw material, with a rapid and robust textile-inspired assembly strategy. Fetal membranes were collected after cesarean deliveries at term. Once isolated by dissection, HAM sheets were cut into ribbons that could be further processed by twisting into threads. Characterization of the HAM yarns (both ribbons and threads) showed that their physical and mechanical properties could be easily tuned. Since our clinical strategy will be to provide an off-the-shelf allogeneic implant, we studied the effects of decellularization and/or gamma sterilization on the histological, mechanical, and biological properties of HAM ribbons. Gamma irradiation of hydrated HAMs, with or without decellularization, did not interfere with the ability of the matrix to support endothelium formation in vitro. Finally, our HAM-based, woven tissue-engineered vascular grafts (TEVGs) exhibited clinically relevant mechanical properties. Thus, this study demonstrates that human, completely biological, allogeneic, small-diameter TEVGs can be produced from HAM, thereby avoiding costly cell culture and bioreactors.

Outcomes of Femoropopliteal Bypass for Lifestyle-Limiting Claudication in the Endovascular Era

INTRODUCTION

Outcomes after femoropopliteal bypass for intermittent claudication (IC) remain unclear in the endovascular era.

METHODS

A multi-institutional database was retrospectively queried for all femoropopliteal bypass procedures performed between 1995 and 2020. Demographics, operative details, and outcomes were documented. A statistical analysis included Kaplan-Meier curves and Cox proportional hazards ratios (HR).

RESULTS

A total of 282 patients underwent femoropopliteal bypass surgery for IC. Median age was 68 y (interquartile range, 61-73 y). Bypass conduits included great saphenous vein (GSV) (48.2%), prosthetic grafts (48.9%), and non-GSV autogenous grafts (2.8%). Distal bypass target was above-knee in 62.1% and below-knee in 37.9% of patients. The most common postoperative complications were wound infections (14.2%) followed by unplanned 30-d hospital readmissions (12.4%). Mortality rates were low at 0.4% (30 d) and 3.2% (1 y). Five-year primary patency rates trended highest for claudicants undergoing above-knee bypass with GSV conduit (log-rank P = 0.065). Five-year amputation-free survival rates were highest using GSV conduit regardless of distal bypass target (log-rank P = 0.017). On a multivariable analysis, age (HR 1.02 [1.00-1.04], P = 0.023) and active smoking (HR 1.48 [1.06-2.06], P = 0.021) were identified as risk factors for diminished primary graft patency. Risk factors for amputation-free survival included age (HR 1.03 [1.01-1.05], P < 0.001) and GSV conduit type (HR 0.65 [0.46-0.90], P = 0.011).

CONCLUSIONS

Femoropopliteal bypass among claudicants is associated with high rates of wound infection and hospital readmission. Active smoking portends worse outcomes in this population. These data may inform clinical decision-making regarding surgical intervention for claudication in the endovascular era.

Alternative autologous and biologic conduits have worse outcomes than prosthetic grafts for infrainguinal bypass in patients with chronic limb-threatening ischemia

OBJECTIVE

Single segment great saphenous vein (GSV) is the preferred conduit in infrainguinal bypass. Alternative autologous conduits (AAC) and nonautologous biologic conduits (NABC) are thought to be a better alternative to traditional prosthetic conduits (PC) in the absence of GSV. In this study we analyzed the outcomes of these alternative conduits in lower extremity bypasses (LEB) in patients with chronic limb-threatening ischemia.

METHODS

The Vascular Quality Initiative LEB database from 2003 to 2020 was queried for this study, to identify LEB in patients with chronic limb-threatening ischemia. Primary outcomes were graft patency, major adverse limb events (MALE), and MALE-free survival at 1 year. Standard statistical methods were used as appropriate.

RESULTS

We identified 22,671 LEB procedures (12,810 GSV, 6002 PC, 1907 AAC, and 1952 NABC). Compared with the GSV group, the other conduit patients were significantly older, had more comorbidities, had an increased rate of prior lower extremity interventions, had a higher rate of infrageniculate bypass targets, and were less ambulatory at baseline. The PC, AAC, and NABC groups had significantly higher rates of postoperative morbidity compared with the GSV group. The PC group had a higher 30-day mortality compared with the GSV, AAC, and NABC groups (3% PC vs 2% GSV, 2% AAC, 2% NABC; P = .049). Both PC and NABC had higher 1-year mortality compared with GSV and AAC (13% PC and 13% NABC vs 10% GSV, 10% AAC; P = .02). In an adjusted Cox regression model (stratified by infrageniculate target and adjusted for age, comorbidities, and prior vascular interventions) PC was not significantly different from GSV, but AAC (hazard ratio [HR], 1.41; 95% confidence interval [CI], 1.19-1.67; P < .001) and NABC (HR, 1.9; 95% CI, 1.61-2.25; P < .001) were associated with an increased risk of loss of primary patency. A similar association with MALE was observed: both AAC (HR, 1.35; 95% CI, 1.15-1.58; P < .001) and NABC (HR, 1.8; 95% CI, 1.53-2.11; P < .001) were associated with an increased risk of MALE compared with GSV; PC was not significantly different from GSV.

CONCLUSIONS

In the absence of GSV, alternative conduits (autologous or nonautologous biologic) do not confer a benefit with regard to graft patency or MALE compared with PCs. Increased operating time or costs associated with the use of these conduits is not justified based on this study.

Bioengineering Human Tissues and the Future of Vascular Replacement

Cardiovascular defects, injuries, and degenerative diseases often require surgical intervention and the use of implantable replacement material and conduits. Traditional vascular grafts made of synthetic polymers, animal and cadaveric tissues, or autologous vasculature have been utilized for almost a century with well-characterized outcomes, leaving areas of unmet need for the patients in terms of durability and long-term patency, susceptibility to infection, immunogenicity associated with the risk of rejection, and inflammation and mechanical failure. Research to address these limitations is exploring avenues as diverse as gene therapy, cell therapy, cell reprogramming, and bioengineering of human tissue and replacement organs. Tissue-engineered vascular conduits, either with viable autologous cells or decellularized, are the forefront of technology in cardiovascular reconstruction and offer many benefits over traditional graft materials, particularly in the potential for the implanted material to be adopted and remodeled into host tissue and thus offer safer, more durable performance. This review discusses the key advances and future directions in the field of surgical vascular repair, replacement, and reconstruction, with a focus on the challenges and expected benefits of bioengineering human tissues and blood vessels.

Society for Vascular Surgery Appropriate Use Criteria for Management of Intermittent Claudication

The Society for Vascular Surgery (SVS) Appropriate Use Criteria (AUC) for Management of Intermittent Claudication were created using the RAND appropriateness method (RAM) which is a validated and standardized methodology that combines best-available evidence from medical literature with expert opinion, using a modified-Delphi process. These criteria serve as a framework upon which individualized patient and clinician shared decision-making can grow. These criteria are not absolute. AUC should not be interpreted as a requirement to administer treatments rated as appropriate (benefit outweighs risk). Nor should AUC be interpreted as a prohibition on treatments rated as inappropriate (risk outweighs benefit). There will be clinical situations in which moderating factors, not included in these AUC, will shift the appropriateness level of a treatment for an individual patient. Proper implementation of AUC calls for a description of those moderating patient factors. For scenarios with an indeterminate rating, clinician judgement combined with best available evidence should determine treatment strategy. Importantly, these are scenarios in need of mechanisms to track treatment decisions and outcomes. AUC should be revisited on a periodic basis to ensure that these criteria remain relevant. The panelists rated 2280 unique scenarios for the treatment of intermittent claudication (IC) in the aortoiliac, common femoral and femoropopliteal segment in Round 2 rating. Of these, only 9 (0.4%) had disagreement according to the IPRAS formula, indicating an exceptionally high degree of consensus among the panelists. [Note, post-hoc, the term, "inappropriate," was replaced with the term "R>B" (risk outweighs benefit). The term "appropriate" was also replaced with "B>R" (benefit outweighs risk)]. The key principles for the management of intermittent claudication reflected within these AUC are: (1) Exercise therapy is a preferred initial management strategy for all patients with IC. (2) For patients who have not completed exercise therapy, invasive therapy may provide net benefit in selected patients with IC who are non-smokers, are taking optimal medical therapy, are considered low physiologic and technical risk, and who are experiencing severe lifestyle limitation and/or short walking distance. (3) Considering the long-term durability of currently available technology, invasive interventions for femoropopliteal disease should be reserved for patients with severe lifestyle limitation and short walking distance. (4) In the common femoral segment, open common femoral endarterectomy provides greater net benefit than endovascular intervention for the treatment of IC. (5) In the infrapopliteal segment, invasive intervention for the treatment of intermittent claudication is of unclear benefit and may be harmful.

Clinical Effect of Revascularization Strategies and Pharmacologic Treatment on Long-Term Results in Patients with Advanced Peripheral Artery Disease with TASC C and D Femoropopliteal Lesions

Background

This study was to assess the clinical outcome and associated parameters of endovascular therapy (EVT group) and bypass surgery (bypass group) in patients with long femoropopliteal TransAtlantic Inter-Society Consensus II (TASC II) C and D peripheral artery disease (PAD).

Methods

187 patients who underwent successful EVT or bypass surgery were assessed. The endpoints included the events of cardiovascular disease (CVD) and lower-extremity amputation (LEA), 3-year primary patency, and 3-year amputation-free survival (AFS).

Results

The 3-year primary and secondary patency rates were better in the bypass group (P=0.007 and P=0.039, respectively), while the incidences of LEA, new CVD events, and mortality were comparable between groups. Weighted multivariate Cox analyses showed that cilostazol treatment (hazard ratio (HR): 0.46, 95% confidence interval (CI): 0.3–0.72, P=0.001), statin treatment (HR: 0.54, 95% CI: 0.33–0.9, P=0.014), and direct revascularization (DR) (HR: 0.47, 95% CI: 0.29–0.74, P=0.001) were predictive factors of 3-year primary patency. Kaplan–Meier curve analyses of time-to-primary cumulative AFS showed that nondiabetes mellitus, mild PAD, and cilostazol and statin treatment were correlated with a superior 3-year AFS (log rank test, P=0.001, P < 0.001, P=0.009, and P=0.044, respectively).

Conclusions

Endovascular stenting based on the angiosome concept and bypass surgery provide comparable benefits for the treatment of long, advanced femoropopliteal lesions after a short follow-up period, whereas cilostazol therapy for more than 3 months, aggressive treatment of dyslipidemia, and surgical revascularization were associated with higher primary patency.

Facilitation of adhesion and spreading of endothelial cells on silicone oxide-coated dacron material by microwave-excited low-pressure plasma

Objectives

Autologous transplants are still the means of choice for bypass surgery. In addition to good tolerability, there is a reduced thrombogenicity and fewer neointima hyperplasia compared to artificial materials. However, since viable transplants are limited, attempts are being made to improve existing artificial vascular prosthesis material. Next to the reduction of thrombogenicity, a rapid endothelialization of the vascular graft should reduce intimal hyperplasia and thus prevent stenoses. The effect of newly developed silicon oxide coatings on the growth of endothelial cells was therefore the goal of this work in a cell culture study.

Methods

A woven, uncoated polyethylene terephthalate (PET) vessel prosthesis was used. The coating process was carried out in a low-pressure plasma reactor in a multi-step process. After preparation of the vacuum chamber hexamethyldisiloxane (HDMSO) with oxygen was evaporated using argon plasma. By this an approx. 1 nm thin adhesion promoter layer was separated from plasma and HMDSO. The silicone oxide barrier layer was applied to the PET vessel samples. The carbon content of the layer could be selectively altered by changing the HMDSO oxygen flow ratio, resulting in coatings of 100 nm, 500 nm, and 1,000 nm. In addition, two different oxygen-to-HMDSO ratios were used. To achieve a carbon coating as low as possible, the ratio was set to 200:1. A carbon-rich layer was obtained with the 1:1 setting. The various coatings were then examined for their surface texture by scanning electron microscopy (SEM) as well as by cell culture experiments for cell viability and growth using EA.hy 926 cells.

Results

SEM showed no changes in the surface morphology; however a layer thickness of 1,000 nm showed peeled off coating areas. Alamar blue assays showed a significantly higher metabolic activity (p=0.026) for the coating 500 nm, ratio 200:1 compared to untreated control samples and a significantly lower metabolic activity (p=0.037) of the coating 500 nm, ratio 1:1 compared to the coating 500 nm, ratio 200:1. This underlines the apparent tendency of the 1:1 coating to inhibit the metabolic activity of the cells, while the 200:1 coating increases the activity. Fluorescence microscopy after calcein acetoxymethyl ester (AM) staining showed no significant difference between the different coatings and the uncoated PET material. However, a tendency of the increased surface growth on the coating 500 nm, ratio 200:1, is shown. The coatings with the ratio 1:1 tend to be less densely covered.

Conclusions

The results of this work indicate a great potential in the silicon coating of vascular prosthesis material. The plasma coating can be carried out easy and gently. Cell culture experiments demonstrated a tendency towards better growth of the cells on the 200:1 ratio coating and a poorer growth on the carbon-rich coating 1:1 compared to the uncoated material. The coating with silicon oxide with a thickness of 500 nm and an oxygen-HMDSO ratio of 200:1, a particularly low-carbon layer, appears to be a coating, which should therefore be further investigated for its effects on thrombogenicity and intimal hyperplasia.

Endovascular Treatment of Long Femoropopliteal Lesions with Contiguous Bare Metal Stents

OBJECTIVES

Recent controversies on the use of drug coated/eluting devices in the arteries of the lower extremities renewed the focus on the evaluation of more conventional techniques. The results of the stenting of short and/or intermediate femoro-popliteal lesions are well known, but little data relate to the endovascular treatment of long femoro-popliteal lesions with contiguous bare metal stents (ETLFBS). The objective of this study was to report our results of ETLFBS.

MATERIAL AND METHODS

Between January 2014 and December 2017, 1233 patients had an infrainguinal angioplasty in our center. The files of patients treated for femoropopliteal lesions longer than 250 mm using extensive stenting with contiguous bare metal stents were reviewed and analyzed. The primary outcome was the 12-month primary patency, defined by the absence of restenosis (≥50%) and/or reintervention on the target lesion. Continuous data were expressed as mean and standard deviation. Survival analysis was carried out according to Kaplan-Meier.

RESULTS

Overall, 64 patients aged 80 ± 11 years were included, with 49 (76.6%) presenting with critical limb ischemia. Lesions were classified as TASC D in 54.7% of the cases. The length of the lesions was 295 ± 64 mm and 3 ± 1 stents were implanted. The 30-day mortality was null but two patients (3.1%) presented nonvascular major complications. With a follow-up of 27 ± 17 months, 22 patients (34.3%) died including three of vascular causes. The healing of the trophic disorder was obtained in 77.5% of the cases. The rate of amputation was 10.9%. The 6-, 12-, and 24-month primary patency rates were 79.7%, 66.6%, and 60.9%, respectively. The 6-, 12-, and 24-month rates of freedom from target lesion revascularization were 96.3%, 73.9%, and 71.9%, respectively. The 6-, 12-, and 24-month survival rates were 90.3%, 83.6%, and 65.6%, respectively.

CONCLUSIONS

The 12-month primary patency rate of ETLFBS is acceptable. This strategy constitutes an acceptable alternative in patients presenting with critical limb ischemia and a limited life expectancy.

Outcomes of bypass and endovascular interventions for advanced femoropopliteal disease in patients with premature peripheral artery disease

OBJECTIVE

Patients with premature peripheral artery disease (PAD), defined as age ≤50 years at presentation, have had poor outcomes with open and endovascular lower extremity revascularization. It is unclear whether either strategy is associated with better outcomes because comparative studies have been limited to case series in this patient population. The aim of the present study was to compare the outcomes of patients with premature PAD who had undergone bypass or endovascular revascularization for advanced femoropopliteal disease. Our hypothesis was that open bypass would provide superior long-term outcomes compared with endovascular intervention for patients with premature advanced femoropopliteal PAD.

METHODS

All the patients with premature PAD who had undergone isolated femoropopliteal lower extremity revascularization and included in the Vascular Quality Initiative infrainguinal bypass and peripheral vascular intervention files were reviewed from 2003 through 2019. Propensity score matching (1:1) was performed between patients who had undergone femoropopliteal bypass and endovascular interventions for isolated femoropopliteal Trans-Atlantic Classification System C or D lesions. The 1-year outcomes, including reintervention, patency, major amputation, and mortality, were analyzed.

RESULTS

Of the 2538 included patients, 902 had undergone isolated femoropopliteal endovascular intervention and 1636 had undergone femoropopliteal bypass. The endovascular intervention group were more likely to have diabetes (68.9% vs 54.0%; P < .001), coronary artery disease (31.0% vs 23.0%; P < .001), renal failure requiring dialysis (14.2% vs 7.2%; P < .001), and claudication (45.1% vs 36.6%; P < .001) compared with the bypass group. After propensity score matching, 466 patients were in each group with no significant differences in the baseline characteristics. Perioperative morbidity was higher with femoropopliteal bypass compared with endovascular intervention (12.0% vs 7.9%; P = .038); however, the rates of major amputation and mortality were not different. At 1 year, patients who had undergone femoropopliteal bypass were less likely to require reintervention (17.0% vs 25.2%; P = .012). However, no differences were found in major amputation (7.7% vs 7.9%; P = .928) or mortality (5.2% vs 5.2%; P = 1.00). Propensity score matching was also performed between femoropopliteal bypass with the great saphenous vein and isolated femoropopliteal endovascular interventions, and the outcomes were similar.

CONCLUSIONS

For patients with premature PAD and advanced femoropopliteal disease, bypass surgery decreased the reintervention rate at 1 year but was associated with increased perioperative morbidity and hospital length of stay compared with endovascular therapy. No differences were found in major amputation or mortality between the two strategies.

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

OBJECTIVE

To 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).

DESIGN

Retrospective single-centre matched case-control study.

METHODS

From 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.

RESULTS

After 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).

CONCLUSIONS

HePTFE provided 5-year similar results to those obtained with use of the ASV in equivalent patients with CLI undergoing below-knee or tibial bypass.

Resurrection of Chronically Occluded Prosthetic Bypass Grafts in a Single Stage with Suction Thrombectomy and Intervention

BACKGROUND

Peripheral arterial occlusive disease (PAOD) continues to be a vexing problem despite the advent of endovascular techniques augmenting traditional open repair. At our institution, we have found there is a growing number of patients with PAOD who are vein-challenged and have undergone prosthetic bypass previously for infrainguinal arterial reconstruction. When occluded, these grafts have been abandoned for a new bypass strategy or amputation. We present a novel technique of reestablishing flow through chronically occluded prosthetic bypass grafts.

METHODS

A retrospective review of a prospectively maintained database compiled at 2 institutions between 2016 and 2019 was performed. Six patients had previous prosthetic bypass grafts with 4 patients having femoral to popliteal grafts, 1 patient with a femoral to femoral graft, and 1 with a femoral to posterior tibial bypass graft. All patients had an attempted single-stage intervention to clear chronically occluded grafts.

RESULTS

A total of 6 patients were included in the study. Indications for intervention were chronic, critical limb ischemia with tissue loss (3), severe claudication (2), and acute on chronic limb ischemia (1). Average time from bypass to suction thrombectomy was 29 months (6-60 months). Mean patency duration is 13 months (1-28 months). Adjunctive procedures include overnight lysis to improve outflow in 1 patient (16.6%), drug-coated balloon angioplasty (83.3%), or stents (83.3%). There were no embolic complications during these procedures. All (2) wounds healed and all are maintained on full-dose anticoagulation and/or antiplatelet therapy.

CONCLUSIONS

Often, the timing of bypass graft occlusion is unknown, and the risk of embolism with lysis for chronically occluded bypass grafts is concerning with traditional peripheral intervention techniques. We report a new and unique minimally invasive approach to resurrect chronically occluded prosthetic bypass grafts often successful in just one stage. This tool offers an alternative technique for limb salvage in complex patients and as use increases, requires further interrogation.

The SELUTION SLR™ drug-eluting balloon system for the treatment of symptomatic femoropopliteal lesions

Endovascular treatment has become first line therapy for the treatment of femoropopliteal disease. Drug-coated devices play a key role in maintaining vessel patency. In the past antiproliferative coating of drug-coated balloons (DCBs) exclusively consisted of paclitaxel. Use of limus drugs was limited by a short residency time in the vessel wall. Besides the drug, the SELUTION SLR™ drug-eluting balloon system consists of a coating formulation of four excipients. The first excipient is a biodegradable polymer (poly(lactic-co-glycolic acid)) that is intermixed with the sirolimus to form micro-reservoirs and regulates drug release via matrix degradation. This review summarizes the existing pre-clinical and clinical literature on treatment of femoropopliteal artery lesions with the SELUTION SLR DCB.

Asia-Pacific Consensus Statement on the Management of Peripheral Artery Disease: A Report from the Asian Pacific Society of Atherosclerosis and Vascular Disease Asia-Pacific Peripheral Artery Disease Consensus Statement Project Committee

BACKGROUND

Peripheral artery disease (PAD) is the most underdiagnosed, underestimated and undertreated of the atherosclerotic vascular diseases despite its poor prognosis. There may be racial or contextual differences in the Asia-Pacific region as to epidemiology, availability of diagnostic and therapeutic modalities, and even patient treatment response. The Asian Pacific Society of Atherosclerosis and Vascular Diseases (APSAVD) thus coordinated the development of an Asia-Pacific Consensus Statement (APCS) on the Management of PAD.

OBJECTIVES

The APSAVD aimed to accomplish the following: 1) determine the applicability of the 2016 AHA/ACC guidelines on the Management of Patients with Lower Extremity Peripheral Artery Disease to the Asia-Pacific region; 2) review Asia-Pacific literature; and 3) increase the awareness of PAD.

METHODOLOGY

A Steering Committee was organized to oversee development of the APCS, appoint a Technical Working Group (TWG) and Consensus Panel (CP). The TWG appraised the relevance of the 2016 AHA/ACC PAD Guideline and proposed recommendations which were reviewed by the CP using a modified Delphi technique.

RESULTS

A total of 91 recommendations were generated covering history and physical examination, diagnosis, and treatment of PAD-3 new recommendations, 31 adaptations and 57 adopted statements. This Asia-Pacific Consensus Statement on the Management of PAD constitutes the first for the Asia-Pacific Region. It is intended for use by health practitioners involved in preventing, diagnosing and treating patients with PAD and ultimately the patients and their families themselves.

Optical Coherence Tomography Contribution Assessment in the Revascularization of Long Femoropopliteal Occlusive Lesions (TASC C and D): A Randomized Trial

BACKGROUND

Endovascular treatment has become the first-line revascularization technique for femoropopliteal lesions. This technique lacks reliable and accurate morphological control of the arterial segment treated. Intraoperative 2-dimensional angiogram consumes iodinated contrast media and increases X-ray exposure; this subsequently provides no 3-dimensional information on the quality of the revascularization completed, what could explain some of the early and late failures of the technique. We evaluated whether intraoperative optical coherence tomography (OCT) control in addition to standard angiogram could improve the primary patency rate at 12 months in comparison to standard angiogram alone in patients with occlusive femoropopliteal lesions.

METHODS

The tomography by optical coherence in femoral artery trial is a multicentric, prospective, randomized, controlled, and single-blind study including patients with long de novo occlusive femoropopliteal lesions. The randomization will be achieved in 2 balanced groups of patients after crossing successfully the lesion: group 1 with intraoperative OCT control in addition to standard angiogram and group 2 with standard angiogram alone. The randomization will be stratified by center. The protocol has been submitted and approved by a French ethic's committee under reference number CPP2019-12-098. The study has been registered under the reference number NCT04434586 on the Web site of clinicaltrials.gov.

RESULTS

The primary outcome of the study is the primary patency at 12 months. The number of patients who need to be treated is 166 (83 in each group) considering 5% of no workable data. Symptoms' improvement, target lesion revascularization, target vessel revascularization, quality-of-life questionnaires, cost utility, and cost effectiveness will be analyzed as secondary end-point variables at 12 months.

CONCLUSIONS

The present study is to evaluate the potential benefit for patients on the result of endovascular revascularization of long occlusive femoropopliteal lesion at 12 months when using intraoperative OCT control.

Arm Vein versus Small Saphenous Vein for Lower Extremity Bypass in the Absence of Both Great Saphenous Veins

BACKGROUND

Bypass surgery remains the gold standard for long and complex arterial occlusions in the lower limb. The vein is regarded superior to prosthetic conduits in peripheral arterial bypass surgery. However, this option is often limited because of previous bypass, stripping, or poor quality of the ipsilateral and/or contralateral great saphenous vein (GSV). Under these circumstances, the arm vein (AV) and small saphenous vein (SSV) are the only alternative autologous vein grafts.

METHODS

We analyzed all consecutive patients treated at an academic tertiary referral center between January 1998 and July 2018 using either the AV or SSV as the main peripheral bypass graft. Study end points were primary patency, secondary patency, limb salvage, and survival.

RESULTS

In total, 416 bypass procedures using exclusively AV (n = 327) or SSV (n = 89) were performed. There was a predominance of male gender. The majority of risk factors were evenly distributed between groups. The mean follow-up period was 2.3 years (0.9 to 13.3 years). Five-year primary and secondary patency rates were 39% (95% CI: 31-47%) and 67% (59-75%) for AV and 53% (41-66%) and 76% (67-86%) for SSV, respectively (P = 0.2 and 0.25). The five-year limb salvage and survival rates were 71% (68-81%) and 84% (77-90%) for AV and 78% (67-88%) and 90% (82-98%) for SSV, respectively (P = 0.52 and 0.11).

CONCLUSIONS

Both AV and SSV are equally effective alternatives for peripheral bypass if no GSV is available. Although there was a trend toward better results with the SSV, there was no significant difference between the 2 options.

Arterial reconstruction using the donor's gonadal vein in living renal transplantation with multiple renal arteries: a case report and a literature review

Background

Arterial reconstruction is one of the paramount procedures in kidney transplantation (KT) and greatly important if the procured kidney has multiple renal arteries (MRA). Despite various established techniques for arterial reconstruction, sometimes, the surgeon finds performing arterial anastomoses challenging in case of MRA. In our case, the donor’s gonadal vein and recipient’s internal iliac artery graft were used for arterial anastomoses, and 3 years after KT, the allograft did not present vascular complications.

Case presentation

A 34-year-old man underwent ABO-incompatible preemptive living KT. The allograft had three renal arteries and four renal veins. After donor nephrectomy, arterial reconstruction was performed on a back table. These arteries were reconstructed into one piece using the recipient’s internal iliac artery graft. The two arteries at the middle of the renal hilum were reconstructed using the conjoined method. As the superior renal artery was too short to anastomose, the donor’s gonadal vein was used for extension. The internal iliac artery graft was anastomosed to the original internal iliac artery. Intraoperative Doppler ultrasonography revealed that the blood flow in each renal artery was adequate, resulting in sufficient blood flow throughout the allograft. The allograft function was maintained with a serum creatinine level of approximately 0.9 mg/dL without vascular complications 3 years after KT.

Conclusions

The donor’s gonadal vein can be a candidate for extension of the renal artery in the allograft with MRA. Further follow-up is needed for the assessment of long-term outcomes.

Midterm Results of a Japanese Prospective Multicenter Registry of Heparin-Bonded Expanded Polytetrafluoroethylene Grafts for Above-the-Knee Femoropopliteal Bypass

BACKGROUND

This study prospectively analyzed the midterm results of above-the-knee femoropopliteal bypass (AKb) using bioactive heparin-bonded expanded polytetrafluoroethylene (HB-ePTFE) graft in patients with femoropopliteal occlusive disease.

METHODS AND RESULTS

This prospective, multicenter, non-randomized study reviewed limbs undergoing AKb with HB-ePTFE graft for femoropopliteal lesion in 20 Japanese institutions between July 2014 and October 2017. Primary efficacy endpoints were primary, primary assisted, and secondary graft patency. Safety endpoints included any major adverse limb event and perioperative mortality. During the study period, 120 limbs of 113 patients (mean age, 72.7 years) underwent AKb with HB-ePTFE grafts. A total of 45 patients (37.5%) had critical limb ischemia and 17 (15.0%) were on hemodialysis (HD). Median duration of follow-up was 16 months (range, 1-36 months). Estimated 1- and 2-year primary, primary assisted, and secondary graft patency rates were 89.4% and 82.7%, 89.4% and 87.2%, and 94.7% and 92.5%, respectively. On univariate analysis of 2-year primary graft patency, having 3 run-off vessels, cuffed distal anastomoses, no coronary artery disease, and no chronic kidney disease requiring HD were significantly associated with favorable patency.

CONCLUSIONS

AKb using HB-ePTFE grafts achieved favorable 2-year graft patency. AKb using HB-ePTFE grafts may therefore be an acceptable, highly effective treatment option for femoropopliteal artery lesions.

Computed Tomography Angiography in the Assessment of Great Saphenous Vein as Conduit for Infrainguinal Bypass Surgery

INTRODUCTION

The great saphenous vein (GSV) is commonly used as a conduit during infrainguinal bypass (IIB) and is usually well seen on computed tomography angiography (CTA) which is frequently performed for preoperative planning. In this study, we asked whether CTA could replace ultrasonography (US) as the primary mode of conduit assessment, by comparing GSV measurements for patients who underwent both CTA and US vein mapping prior to IIB.

METHODS

All IIB that were completed in the six-and-a-half-year period from January 1, 2012, to July 31, 2018, at the authors' institution were examined. Great saphenous vein measurements were analyzed for patients who had undergone both CTA and US vein mapping. Correlation between the measurements was calculated with the Pearson correlation coefficient. Data were then examined using Bland-Altman plots. Then categorical analysis was used to determine the adequacy of GSV for use as a bypass conduit.

RESULTS

There were 302 patients who underwent IIB, with 73 legs, in 47 patients, examined with CTA and US. Computed tomography angiography and US measurements were moderately correlated (r = 0.531) across all measurement locations. Correlation progressively reduced distally (proximal thigh r = 0.534, midthigh r = 0.536, knee r = 0.35, midcalf r = 0.185, P = .074, ankle r = 0.078, P = .485). Bland-Altman plots of the pooled location data demonstrated no systematic bias. However, the upper and lower limits of agreement were wide, between -2.02 and +2.37 mm, demonstrating a lack of agreement between CTA and US. Analysis of each location revealed similar findings. A receiver operator characteristic curve was constructed based on a minimum US GSV diameter for adequate bypass conduit of 3 mm. The CTA value that maximized the Youden index was 3.8 mm.

CONCLUSION

The level of error between CTA and US measurements, demonstrated by the large limits of agreement on Bland-Altman plots, would not be clinically acceptable. However, if a larger threshold is accepted, CTA has the potential to replace preoperative US vein mapping of GSV.

N-Acetylcysteine Does Not Improve the Endothelial and Smooth Muscle Function in the Human Saphenous Vein

Oxidative stress can lead to vein graft dysfunction in the saphenous vein. This ex vivo study is aimed to compare the effects of increasing concentrations of the antioxidant N-acetylcysteine (NAC) with heparinized saline (HS) on endothelial and smooth muscle function in the human saphenous vein. Long saphenous vein segment obtained during infrainguinal bypass surgery was divided into 7 rings; 1 immersed in HS and the remaining 6 in increasing NAC concentrations (0.0025%, 0.005%, 0.01%, 0.02%, 0.03%, and 0.04%). Rings were mounted in an organ bath, and relaxant responses to acetylcholine and sodium nitroprusside were assessed through isometric tension studies. Endothelium-dependent relaxations were observed in 77 vein segments from 11 patients. No significant difference was seen in veins treated with either lower NAC concentrations (0.0025%, 0.005%, 0.01%, 0.02%, and 0.03%) or HS. However, HS-treated veins showed significantly better relaxation compared to those treated with maximum (0.04%) NAC ( P < .05). Endothelium-independent relaxations were observed in 91 segments from 13 patients. No difference in relaxation was observed between veins treated with HS or any of the NAC concentrations. In conclusion, lower NAC concentrations do not offer better endothelial protection than HS, whereas the highest NAC concentration has a detrimental effect on endothelium-dependent relaxation. Moreover, NAC did not show beneficial effect on direct smooth muscle relaxation.

Thrombosis of a Long-Segment Aneurysm from the Iliac to Popliteal Artery Associated with Arteriovenous Malformation and Varicose Veins

A 58-year-old male patient with severe claudication due to thrombosis of the left ilio-femoro-popliteal artery aneurysm. He also had a venous stasis ulcer with a history of multiple embolotherapy of arteriovenous malformation. Duplex sonography revealed reflux and varicose veins of the left great saphenous vein (GSV). A sequential bypass surgery was performed that consisted of excision of the left external iliac and common femoral artery aneurysm, external iliac to deep femoral interposition with an expanded polytetrafluoroethylene graft, and femoro-posterior tibial artery bypass with the reversed left GSV. Symptoms of claudication were alleviated and the chronic ulcer was healed in time. To our knowledge, this is the first report of successful bypass in a patient with arterial aneurysm, arteriovenous malformation, and venous insufficiency that can be diagnosed as an atypical case of Parkes Weber syndrome. Long-term follow-up is needed to define the fate of aneurysms and varicose vein graft.

Successful repair of a popliteal aneurysm with saphenous vein graft in a patient with Marfan syndrome

Marfan syndrome is an autosomal dominant disorder caused by mutations in the fibrillin 1 gene (FBN1). This leads to defective elasticity of connective tissue in the arterial wall. Aortic aneurysms and dissections are the most common vascular anomalies; the incidence of peripheral artery aneurysms is not well understood. Treatment options for infrainguinal disease are limited as endovascular interventions are generally contraindicated. The best conduit for arterial reconstruction is also unknown because there is concern that saphenous vein may become aneurysmal. Currently, there are few case reports regarding outcomes of infrainguinal arterial reconstructions, and follow-up has been very short term. We report a rare case of successful repair of a popliteal aneurysm using a saphenous vein graft in a patient with Marfan syndrome.

Ten Year Experience of Using Cryopreserved Arterial Allografts for Distal Bypass in Critical Limb Ischaemia

OBJECTIVE/BACKGROUND

In critical limb ischaemia (CLI), current guidelines recommend revascularisation whenever possible, preferentially through endovascular means. However, in the case of long occlusions or failed endovascular attempts, distal bypasses still have a place. Single segment great saphenous vein (GSV), which provides the best conduit, is often not available and currently there is no consensus about the best alternative graft.

METHODS

From January 2006 to December 2015, 42 cryopreserved arterial allografts were used for a distal bypass. Autologous GSVs or alternative autologous conduits were unavailable for all patients. The patients were observed for survival, limb salvage, and allograft patency. The results were analysed with Kaplan-Meier graphs.

RESULTS

Estimates of secondary patency at one, two and five years were 81%, 73%, and 57%, respectively. Estimates of primary patency rates at one, two and five years were 60%, 56%, and 26%, respectively. Estimates of limb salvage rates at one, two and five years were 89%, 89%, and 82%, respectively. Estimates of survival rates at one, two and five years were 92%, 76% and 34%, respectively. At 30 days, major amputations and major adverse cardiac events were one and zero, respectively. Six major amputations occurred during the long-term follow up.

CONCLUSION

Despite a low primary patency rate at two years, the secondary patency of arterial allografts is acceptable for distal bypasses. This suggests that cryopreserved arterial allografts are a suitable alternative for limb saving distal bypasses in the absence of venous conduits, improving limb salvage rates and, possibly, quality of life.

Multidisciplinary Care for Critical Limb Ischemia: Current Gaps and Opportunities for Improvement

Critical limb ischemia (CLI), defined as ischemic rest pain or nonhealing ulceration due to arterial insufficiency, represents the most severe and limb-threatening manifestation of peripheral artery disease. A major challenge in the optimal treatment of CLI is that multiple specialties participate in the care of this complex patient population. As a result, the care of patients with CLI is often fragmented, and multidisciplinary societal guidelines have not focused specifically on the care of patients with CLI. Furthermore, multidisciplinary care has the potential to improve patient outcomes, as no single medical specialty addresses all the facets of care necessary to reduce cardiovascular and limb-related morbidity in this complex patient population. This review identifies current gaps in the multidisciplinary care of patients with CLI, with a goal toward increasing disease recognition and timely referral, defining important components of CLI treatment teams, establishing options for revascularization strategies, and identifying best practices for wound care post-revascularization.

Efficacy of Cutting Balloon Angioplasty for Chronic Total Occlusion of Femoropopliteal Arteries

BACKGROUND

Chronic total occlusion (CTO) of femoropopliteal artery (FP) continues to be a lesion subset where maintaining long-term patency after endovascular treatment is challenging. We evaluated the efficacy of cutting balloon angioplasty (CBA) for de novo FP-CTOs in patients with symptomatic lower limb ischemia.

METHODS

Seventy-three limbs of 67 symptomatic patients with de novo FP-CTOs successfully recanalized using CBA alone were enrolled in this study. Primary patency was defined as the absence of recurrent symptoms and no deterioration of the ankle-brachial index (ABI) >0.10 from the immediate postinterventional value.

RESULTS

The mean age was 73.5 ± 7.3 years, and 59.7% of patients had diabetes mellitus. Most lesions were classified as Trans-Atlantic Inter-Society Consensus II type C (n = 18; 24.7%) or type D (n = 44; 60.3%), with mean lesion and occluded lengths of 24.8 ± 11.4 and 17.8 ± 11.2 cm, respectively. No procedure-related adverse events occurred, except one distal embolization. The ABI significantly increased after intervention from 0.52 ± 0.12 to 0.80 ± 0.15 (P < 0.0001), with marked improvement in clinical symptoms (Rutherford stage: 2.7 ± 1.0 to 1.1 ± 1.2, P < 0.0001). The mean follow-up period was 31.2 ± 18.0 months, and the primary patency rates at 12 and 24 months were 75.3% and 60.6%, respectively. The independent predictive factors of failed patency were baseline hemoglobin A1c (P = 0.031, hazard radio [HR] 1.51 per 1%), occluded length ≥15 cm (P = 0.036, HR 2.90), and severe dissection (P = 0.033, HR 2.85). Vessel calcification and diameter did not affect primary patency.

CONCLUSIONS

CBA is a feasible option for endovascular treatment of FP-CTOs. Diabetic status, occlusion length, and severe dissection after CBA are independent negative predictors of long-term patency.