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Copyright of Gefaesschirurgie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Studies reveal variations in the in the origin, number, and branching patterns of the lateral circumflex femoral artery (LCFA). The present study aimed to document such variations and their potential clinical applicability. Thirty-two femoral triangles of 16 embalmed adult human cadavers were dissected to investigate the variation in the origin, number, and branching patterns of LCFA. The main branches of the LCFA were tracked independently for numerical variations in branching pattern. The distance between the origin of LCFA and mid inguinal point (MIP) was also measured in each case. LCFA was most commonly arising from profunda femoris (PF), followed by femoral artery (FA) and common trunk of the femoral artery (CFA). Duplication LCFA was observed in 15 (46.87%) limbs, in 5 (31.25%) cases duplication was only on right side, in 4 (25%) cases duplication was only on left side and in 3 (18.75%), duplication was bilateral. Cases with duplication of LCFA, showed numerical variations with descending pattern being the most common. The average distance of LCFA1 and LCFA2 from mid-inguinal point was 5.77±1.35 cm and 6.14±2.05 cm respectively. Detailed information regarding the occurrence of duplication will be great importance for surgeons, interventional radiologists, and other medical professionals performing procedures in the femoral region. Knowledge of variation of branching pattern of LCFA is utmost important as surgeons use the descending branch of the LCFA in bypass grafting and vascular reconstruction surgeries. [ABSTRACT FROM AUTHOR]

Background: Intermittent Claudication (IC) is exercise pain seen in lower extremity arterial diseases. If it is left untreated, it may be the initial sign of a process leading to amputation. In the present study, the purpose was to compare the postoperative early and mid-term results of the patients who were treated with endovascular methods and those who underwent bypass graft surgery in the treatment due to IC complaints because of isolated Femoropopliteal Arterial Disease. Method: Postoperative first-month, sixth-month, and 12th-month follow-up results, procedure requirements, and demographic characteristics of the 153 patients who underwent femoropopliteal bypass because of isolated Femoropopliteal Arterial Disease and 294 patients who underwent endovascular intervention in our hospital between January 2015 and May 2020 were compared in the study. Results: It was found in demographic characteristics that endovascular intervention was performed more frequently in smokers and graft bypass surgery was performed more frequently in hyperlipidemic patients, and the results were found to be statistically significant. High amputation rates were detected at statistically significant levels in diabetic and hypertriglycemic patients and 1-year primary patency rates were found to be higher in patients who underwent graft bypass surgery. No differences were detected between the two methods in terms of mortality. Conclusion: Interventional treatment modalities must be considered for patients with isolated Femoropopliteal Arterial Disease whose symptoms persist despite exercise and the best medical treatment. We think that Bypass Graft Surgery has more positive results than endovascular interventions when short and medium-term amputation, repetitive intervention needs, and changes in quality of life are compared in patients who receive the same medical treatment. [ABSTRACT FROM AUTHOR]

The frozen elephant trunk (FET) technique can be applied to extensive aortic pathology, including lesions in the aortic arch and proximal descending thoracic aorta. FET is useful for tear-oriented surgery in dissections, managing malperfusion syndrome, and promoting positive aortic remodeling. Despite these benefits, complications such as distal stent-induced new entry and spinal cord ischemia can pose serious problems with the FET technique. To prevent these complications, careful sizing and planning of the FET are crucial. Additionally, since the FET technique involves total arch replacement, meticulous surgical skills are essential, particularly for young surgeons. In this article, we propose several techniques to simplify surgical procedures, which may lead to better outcomes for patients with extensive aortic pathology. In the era of precision medicine, the next-generation FET device could facilitate the treatment of complex aortic diseases through a patient- tailored approach.

Objectives: To determine the influence that the number of patent crural run-off vessels has on short- and mid-term outcomes following femoro-popliteal bypass. Methods: All patients undergoing index femoro-popliteal bypass grafting between 2013 and 19 at our unit were included. Preoperative imaging was used to stratify patients into cohorts with either one or ≥2 patent run-off vessels. Primary outcomes measures included bypass patency and limb salvage rates at one and 3 years post-operatively. Survival analysis was performed using Kaplan–Meier curves and Logrank test. Results: 147 bypasses performed on 143 patients were included. 24 patients had one-vessel run-off and 123 had ≥2 vessels patent. Patients with one-vessel run-off had a higher proportion of emergency admissions (54% vs 41%) and diabetes (42% vs 31%). 31% of patients underwent diagnostic angiogram imaging in addition to having duplex ultrasound and/or computed tomography angiography. There were no significant differences in primary, primary-assisted or secondary patency rates between the cohorts at 12 or 36 months. Limb salvage rates were significantly higher amongst those with ≥2 vessel run-off at 12 (86% vs 71%, p = 0.03) and 36 (85% vs 71%, p = 0.04) months. For those with occluded grafts, a higher proportion of patients with ≥2 vessel run-off subsequently had an attempt at redo bypass grafting. Conclusions: Femoro-popliteal bypass is a reasonable treatment option for patients with one-vessel run-off. However, whilst patency rates are comparable, clinicians should be aware of the lower successful limb salvage rates for patients with one patent vessel (especially those presenting with tissue loss). [ABSTRACT FROM AUTHOR]

Purpose: Based on the clinical need for grafts for vascular tissue regeneration, our group developed a customizable scaffold derived from the human amniotic membrane. Our approach consists of rolling the decellularized amniotic membrane around a mandrel to form a multilayered tubular scaffold with tunable diameter and wall thickness. Herein, we aimed to investigate if silica nanoparticles (SiNP) could enhance the adhesion of the amnion layers within these rolled grafts. Methods: To test this, we assessed the structural integrity and mechanical properties of SiNP-treated scaffolds. Mechanical tests were repeated after six months to evaluate adhesion stability in aqueous environments. Results: Our results showed that the rolled SiNP-treated scaffolds maintained their tubular shape upon hydration, while non-treated scaffolds collapsed. By scanning electron microscopy, SiNP-treated scaffolds presented more densely packed layers than untreated controls. Mechanical analysis showed that SiNP treatment increased the scaffold's tensile strength up to tenfold in relation to non-treated controls and changed the mechanism of failure from interfacial slipping to single-point fracture. The nanoparticles reinforced the scaffolds both at the interface between two distinct layers and within each layer of the extracellular matrix. Finally, SiNP-treated scaffolds significantly increased the suture pullout force in comparison to untreated controls. Conclusion: Our study demonstrated that SiNP prevents the unraveling of a multilayered extracellular matrix graft while improving the scaffolds' overall mechanical properties. In addition to the generation of a robust biomaterial for vascular tissue regeneration, this novel layering technology is a promising strategy for a number of bioengineering applications. [ABSTRACT FROM AUTHOR]

Introduction: Aortoiliac occlusive disease can contribute to lower extremity ischaemic symptoms requiring intervention. Though proximal aorto-femoral bypass surgery has been the mainstay of intervention, the delayed healing in many patients necessitates exploration of other techniques, including sequential revascularisation. Aim: To estimate the outcomes of aortoiliac occlusive disease treated by aorto-femoro-popliteal and distal bypass surgeries. Materials and Methods: A prospective cohort study was conducted to determine the treatment outcomes of 25 patients with aortoiliac occlusive disease visiting a tertiary care centre of Government Stanley Medical College and Hospital, Chennai, Tamil Nadu, India from October 2012 to December 2014. Data regarding the aetiology of the disease, co-morbidities including substance use, degree of disease involvement, and treatment modalities were collected. Data was analysed by Statistical Package for Social Sciences (SPSS) software version 22.0. The Chi-square test was used to compare outcomes with different treatment modalities, and a p-value

Copyright of Hospital a Domicilio is the property of Centro Internacional Virtual de Investigacion en Nutricion and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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. [ABSTRACT FROM AUTHOR]

Introduction: Aortoiliac occlusive disease can contribute to lower extremity ischaemic symptoms requiring intervention. Though proximal aorto-femoral bypass surgery has been the mainstay of intervention, the delayed healing in many patients necessitates exploration of other techniques, including sequential revascularisation. Aim: To estimate the outcomes of aortoiliac occlusive disease treated by aorto-femoro-popliteal and distal bypass surgeries. Materials and Methods: A prospective cohort study was conducted to determine the treatment outcomes of 25 patients with aortoiliac occlusive disease visiting a tertiary care centre of Government Stanley Medical College and Hospital, Chennai, Tamil Nadu, India from October 2012 to December 2014. Data regarding the aetiology of the disease, co-morbidities including substance use, degree of disease involvement, and treatment modalities were collected. Data was analysed by Statistical Package for Social Sciences (SPSS) software version 22.0. The Chi-square test was used to compare outcomes with different treatment modalities, and a p-value <0.05 was considered statistically significant. Results: The mean age of the study participants was 58.3±2 years (range 40 to 70 years). The study noted that the most common aetiology for aortoiliac occlusive disease was atherosclerosis in 18 (72%) cases. The most common associated co-morbidity was smoking in 18 (72%) cases. Abnormal profunda patency was noted in 15 (60%) cases and synthetic Polytetrafluoroethylene (PTFE) was used in 80% of sequential bypass cases. A significantly higher proportion (86.7% vs 30%) of people treated by the sequential procedure achieved relief from claudication pain (p-value<0.05). The complication noted after the proximal bypass was pseudoaneurysm (20%), and the only complication noted after the sequential bypass was graft thrombosis (13.33%). The mean Ankle-brachial Index (ABI) score and ulcer healing time were also significantly higher in the sequential bypass procedure (p-value<0.05). Conclusion: Sequential bypass offers better advantages than proximal bypass for treating aortoiliac occlusive disease. It was found to be a safe and effective method for successful limb salvage, ensuring successful limb revascularisation and sufficient outflow to maintain graft patency. [ABSTRACT FROM AUTHOR]

Autologous vascular arterial or venous graft are not available in 10-40% of patients, due to vascular pathologies, and the utility of decellularized biological scaffolds would be a solution for those cases. The purpose of this research was to obtain a functional acellular xenograft, prior to in-vivo testing as a vascular graft in an experimental animal.

Inflow arterial aneurysms are a rare but serious complication after long term arteriovenous fistulae (AVF), probably due to arterial wall remodelling after an increase in flow and shear stress, and kidney transplantation with immunosuppressive therapy. This study aimed to describe the outcomes of surgical treatment and long term follow up in a large cohort. This prospective cohort study collected data from patients with a true inflow artery aneurysm after AVF creation that was surgically repaired between 2010 and 2022. Anastomotic and infected aneurysms or post-puncture pseudoaneurysms were excluded. Demographic data, access characteristics, symptoms, treatment strategies, and long term follow up were recorded; patency was estimated using Kaplan–Meier survival analysis. During the study period, 28 patients (64% men, mean age 60.1 years) were treated surgically for aneurysmal degeneration of the axillary or brachial (n = 23) or radial (n = 5) artery after an AVF (10 distal, 18 proximal) performed a mean of 18.3 ± SD 7.9 years previously. Most AVFs were ligated or thrombosed, while all patients except one had previously received kidney transplants. Most of the cases (n = 18) were symptomatic: 13 with pain or swelling, four with distal embolisation, and one rupture. They were repaired by aneurysm partial excision and graft interposition (11 great saphenous vein, six ipsilateral basilic vein, three cephalic vein, and two PTFE graft), ligation (n = 3), or direct end to end anastomosis (n = 3). No major complications occurred before discharge, after a mean hospital stay of 2.4 days. After a mean follow up of 4.8 ± 3.3 years, three cases presented complications: two recurrent proximal brachial aneurysms were repaired with an additional proximal interposition graft (one with further late infected pseudoaneurysm) and an asymptomatic post-traumatic graft thrombosis. Five year primary and secondary patency was 84% and 96%, respectively. Aneurysmal degeneration of the inflow artery is an unusual complication during long term follow up of AVFs. Aneurysm excision and, in general, autogenous graft interposition using the saphenous or ipsilateral arm vein is a safe and effective strategy. [ABSTRACT FROM AUTHOR]

Background: Thromboangiitis obliterans (TAO) poses a higher risk of amputation than atherosclerosis obliterans. It is characterized by onset at a relatively young age. There are currently no clear treatment guidelines for TAO other than smoking cessation. In this study, we aimed to identify factors that could influence a favorable prognosis of TAO. Methods: From January 2009 to December 2019, we retrospectively reviewed the initial symptoms, characteristics, treatments, and disease course of 37 patients (45 limbs) with TAO. Logistic regression analysis was performed to investigate factors affecting the course of symptoms that persisted or worsened despite treatment. Results: Patients’ mean age was 37.2±11.4 years, and all patients were men. The mortality rate was 0% during the follow-up period (76.9±51.1 months). All patients were smokers at the time of diagnosis, and 19 patients (51.4%) successfully quit smoking during treatment. When comparing the Rutherford categories before and after treatment, 23 limbs (51.1%) showed improvement, the category was maintained in 11 limbs (24.4%), and 11 limbs (24.4%) worsened. Symptom persistence or exacerbation despite treatment was associated with a higher initial Rutherford category (odds ratio [OR], 1.59; 95% confidence interval [CI], 1.04–2.42; p=0.03) and a higher score of the involved below-knee artery at the time of diagnosis (OR, 2.26; 95% CI, 1.10–4.67; p=0.03). Conclusion: The degree of disease progression at the time of diagnosis significantly affected patients’ prognosis. Therefore, early diagnosis and intervention are important to improve the course of TAO.

Surgical procedures can result in unforeseen vascular injuries. In cases of severe vascular injuries, the involvement of an experienced vascular surgeon in the operation can be life-saving. The aim of this study is to elucidate the surgical approaches and outcomes in vascular injuries that occurred during elective operations of various branches within our institution. Between October 2014 and June 2018, 18 patients required surgery due to unexpected severe vascular injuries. Gender, age, injury site, elective operation, intervention to vascular injury, hemodynamic status, type of anesthesia, mean operation time, and postoperative status of the patients were retrospectively obtained from hospital database. Diagnostic tests and imaging methods were recorded, and the utilization of blood products used during the operation has been investigated. The intensive care unit and service follow-ups of the patients as well as their post-discharge controls were collected from hospital records. Among the patients undergoing vascular intervention, 60% (n=11) experienced arterial injuries, while 40% (n=7) had venous injuries. When examining the type of intervention, all patients, except for one, underwent intervention by placing a side or cross-clamp on the vascular structure. Primary repair was performed in 11 patients, end -to-end repair in 2 patients, PTFE graft placement in 1 patient, saphenous vein interposition in 3 patients, and ligation in 1 patient. Two patients (11%) died during the surgery. As a result, the surgeon should accurately and quickly evaluate findings such as unexplained hypotension, tachycardia, loss of pulse or heat loss during the operation, and should suspect vascular injury. It is possible to reduce mortality and morbidity rates when iatrogenic vascular injuries are diagnosed early. [ABSTRACT FROM AUTHOR]

ObjectiveIncreasing evidence has shown that the risks associated with surgical revascularization for intermittent claudication outweigh the benefits. The aim of our study was to quantify the cost of care associated with perioperative complications after elective lower extremity bypass (LEB) in patients presenting with intermittent claudication.MethodsAll patients undergoing first-time LEB for claudication in the Healthcare Database (2009-2015) were included. The primary outcome was in-hospital postoperative complications, including major adverse limb events (MALE), major adverse cardiac events (MACE), acute kidney injury, and wound complications. The overall crude hospital costs are reported, and a generalized linear model with log link and inverse Gaussian distribution was used to calculate the predicted hospital costs for specific complications.ResultsOverall, 7154 patients had undergone elective LEB for claudication during the study period. The median age was 66 years (interquartile range, 59-73 years), 67.5% were male, and 75.3% were white. Two thirds of patients (61.2%) had Medicare insurance, followed by private insurance (26.9%), Medicaid (7.7%), and other insurance (4.2%). In-hospital complications occurred in 8.5% of patients, including acute kidney injury in 3.0%, MALE in 2.8%, wound complications in 2.3%, and MACE in 1.0%. The overall median crude hospital cost was $11,783 (interquartile range, $8911-$15,767) per patient. The incremental increase in cost associated with a postoperative complication was significant, ranging from $6183 (95% confidence interval, $4604-$7762) for MALE to $10,485 (95% confidence interval, $6529-$14,441) for MACE after risk adjustment.ConclusionsPostoperative complications after elective LEB for claudication are not uncommon and increase the in-hospital costs by 46% to 78% depending on the complication. Surgical revascularization for claudication should be used sparingly in carefully selected patients.

Background: A secondary aortoenteric fistula after an aortic graft replacement or endovascular aortic repair is a rare but devastating complication that leads to extremely high morbidity and mortality. Because reports of vascular graft infection with enteric fistulization complicating in a hybrid aortic repair with renovisceral debranching are limited, the management method such as the extent of removal of the infected graft, reconstruction procedures, and the ideal type of graft are still debatable. Case presentation: We report a successful case of a 73-year-old man presenting a vascular graft infection with duodenal fistulization, 10 years after hybrid endovascular aortic repair with renovisceral debranching for a 60-mm diameter of supra-renal abdominal aortic aneurysm. The patient had a history of polymyalgia rheumatica on oral prednisolone, perigraft seroma, deep vein thrombosis, and an allergy to rifampicin. The patient eventually recovered after partial removal of the grafts, in situ reconstruction using Fusion Bioline vascular prosthesis, primary duodenal repair, application of omental flap, and antibiotics without any evidence of re-infection after 1.5 years. Conclusions: Although hybrid endovascular aortic repair is considered advantageous, especially for the elderly and high-risk patients, due to the avoidance of extracorporeal circulation and thoracotomy; once a devastating complication happens, an optimal treatment method should be considered for patients with several comorbidities. Although our procedures provided favorable results, careful monitoring to avoid re-infection is mandatory. [ABSTRACT FROM AUTHOR]

Rationale: Osseous dysplasia (OD) is a benign fibro-osseous lesion classified as periapical, focal or florid with some rare cases being diagnosed as expansive OD. Patient Concerns: A 43-year-old female presented with gross mandible expansion and tooth displacement. Diagnosis: Imaging scans revealed an expansive lesion in the anterior mandible, with varying opacity in the central region, and other smaller lesions in the region of teeth #37 and #47, consistent with expansive OD. Treatment: Surgical resection followed by immediate reconstruction of the mandibular defect using a microvascularized fibular graft. Outcomes: The patient had a 4-year follow-up, with adequate mandibular bone continuity, mastication, swallowing, and speaking ability reestablished. Take-away Lessons: Immediate reconstruction after large surgical resection is required as tissues retract over time, hampering late reconstructions. Microvascularized fibular graft aims at adequate and functional rehabilitation with osseointegrated implants and long-term follow-up is needed as florid OD may evolve into expansive OD. [ABSTRACT FROM AUTHOR]

Establishing and maintaining a healthy endothelium on vascular and intravascular devices is crucial for the prevention of thrombosis and stenosis. Generating a biofunctional surface on vascular devices to recruit endothelial progenitor cells (EPCs) and endothelial cells (ECs) has proven efficient in promoting in situ endothelialization. However, molecules conventionally used for EPC/EC capturing generally lack structural stability, capturing specificity, and biological functionalities, which have limited their applications. Discovery of effective, specific, and structurally stable EPC/EC capturing ligands is desperately needed. Using the high-throughput One-Bead One-Compound combinatorial library screening technology, we recently identified a disulfide cyclic octa-peptide LXW7 (cGRGDdvc), which possesses strong binding affinity and functionality to EPCs/ECs, weak binding to platelets, and no binding to inflammatory cells. Because LXW7 is cyclic and 4 out of the 8 amino acids are unnatural D-amino acids, LXW7 is highly proteolytically stable. In this study, we applied LXW7 to modify small diameter vascular grafts using a Click chemistry approach. In vitro studies demonstrated that LXW7-modified grafts significantly improved EPC attachment, proliferation and endothelial differentiation and suppressed platelet attachment. In a rat carotid artery bypass model, LXW7 modification of the small diameter vascular grafts significantly promoted EPC/EC recruitment and rapidly achieved endothelialization. At 6 weeks after implantation, LXW7-modified grafts retained a high patency of 83%, while the untreated grafts had a low patency of 17%. Our results demonstrate that LXW7 is a potent EPC/EC capturing and platelet suppressing ligand and LXW7-modified vascular grafts rapidly generate a healthy and stable endothelial interface between the graft surface and the circulation to reduce thrombosis and improve patency. STATEMENT OF SIGNIFICANCE: In this study, One-Bead One-Compound (OBOC) technology has been applied for the first time in discovering bioactive ligands for tissue regeneration applications. Current molecules used to modify artificial vascular grafts generally lack EPC/EC capturing specificity, biological functionalities and structural stability. Using OBOC technology, we identified LXW7, a constitutionally stable disulfide cyclic octa-peptide with strong binding affinity and biological functionality to EPCs/ECs, very weak binding to platelets and no binding to inflammatory cells. These characteristics are crucial for promoting rapid endothelialization to prevent thrombosis and improve patency of vascular grafts. LXW7 coating technology could be applied to a wide range of vascular and intravascular devices, including grafts, stents, cardiac valves, and catheters, where a "living" endothelium and healthy blood interface are needed.

Objective: Calcification of vascular grafts, including polyethylene terephthalate (PET) and expanded polytetrafluoroethylene (ePTFE) grafts may contribute to graft failure, but is under reported. The aim of this study was to review the literature to assess whether vascular graft calcification is deleterious to vascular graft outcomes. Data sources: The Medline and Embase databases were searched. Review methods: A systematic literature search according to PRISMA Guidelines was performed using a combined search strategy of MeSH terms. The MeSH terms used were “calcification, physiologic”, “calcinosis”, “vascular grafting”, “blood vessel prosthesis”, “polyethylene terephthalates”, and “polytetrafluoroethylene”. Results: The systematic search identified 17 cases of PET graft calcification and 73 cases of ePTFE graft calcification over a 35 year period. All cases of PET graft calcification were reported in grafts explanted for graft failure. The majority of cases of ePTFE graft calcification were unexpectedly noted in grafts used during cardiovascular procedures and subsequently removed. Conclusion: Calcification of synthetic vascular grafts is under reported but can compromise the long term performance of the grafts. More data, including specific analysis of radiological findings as well as explant analysis are needed to obtain a more sensitive and specific analysis of the prevalence and incidence of vascular graft calcification and the impact of calcification on synthetic graft outcomes.

Vascular access-induced limb ischemia is a known complication of arteriovenous fistulas and grafts. Many techniques have been adopted to prevent steal in high-risk patients and to treat steal in cases of moderate ischemia not controlled with conservative management. A major factor guiding treatment is access flow volume. Management is different when ischemia is combined with the excessive flow in contrast to the combination with normal flow. We describe the most popular techniques encountered in the English literature as a part of a stepwise approach to treating dialysis access steal syndrome. In absence of ischemia, when cardiac issues emerge due to extreme access flow volumes, some of these techniques are also used to decrease flow and protect the heart. Patient’s history, focused clinical examination, color duplex ultrasound examination, pulse oximetry and an angiogram are essential tools to approach this entity.

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 (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.

BackgroundChronic limb-threatening ischemia (CLTI), defined as ischemic rest pain or tissue loss secondary to arterial insufficiency, is caused by multilevel arterial disease with frequent, severe infrageniculate disease. The rise in CLTI is in part the result of increasing worldwide prevalence of diabetes, renal insufficiency, and advanced aging of the population. The aim of this study was to compare a bypass-first with an endovascular-first revascularization strategy in patients with CLTI due to infrageniculate arterial disease.MethodsWe reviewed the American College of Surgeons National Surgical Quality Improvement Program targeted lower extremity revascularization database from 2012 to 2015 to identify patients with CLTI and isolated infrageniculate arterial disease who underwent primary infrageniculate bypass or endovascular intervention. We excluded patients with a history of ipsilateral revascularization and proximal interventions. The end points were major adverse limb event (MALE), major adverse cardiovascular event (MACE), amputation at 30 days, reintervention, patency, and mortality. Multivariable logistic regression was used to determine the association of a bypass-first or an endovascular-first intervention with outcomes.ResultsThere were 1355 CLTI patients undergoing first-time revascularization to the infrageniculate arteries (821 endovascular-first revascularizations and 534 bypass-first revascularizations) identified. There was no significant difference in adjusted rate of 30-day MALE in the bypass-first vs endovascular-first revascularization cohort (9% vs 11.2%; odds ratio [OR], 0.73; 95% confidence interval [CI], 0.50-1.08). However, the incidence of transtibial or proximal amputation was lower in the bypass-first cohort (4.3% vs 7.4%; OR, 0.60; CI, 0.36-0.98). Patients with bypass-first revascularization had higher wound complication rates (9.7% vs 3.7%; OR, 2.75; CI, 1.71-4.42) compared with patients in the endovascular-first cohort. Compared with the endovascular-first cohort, the incidence of 30-day MACE was significantly higher in bypass-first patients (6.9% vs 2.6%; adjusted OR, 3.88; CI, 2.18-6.88), and 30-day mortality rates were 3.23% vs 1.8% (adjusted OR, 2.77; CI, 1.26-6.11). There was no difference in 30-day untreated loss of patency, reintervention of treated arterial segment, readmissions, and reoperations between the two cohorts. In subgroup analysis after exclusion of dialysis patients, there was also no significant difference in MALE or amputation between the bypass-first and endovascular-first cohorts.ConclusionsCLTI patients with isolated infrageniculate arterial disease treated by a bypass-first approach have a significantly lower 30-day amputation. However, this benefit was not observed when dialysis patients were excluded. The bypass-first cohort had a higher incidence of MACE compared with an endovascular-first strategy. These results reaffirm the need for randomized controlled trials, such as the Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL-2) trial and Best Endovascular vs Best Surgical Therapy in Patients with Critical Limb Ischemia (BEST-CLI), to provide level 1 evidence for the role of endovascular-first vs bypass-first revascularization strategies in the treatment of this population of challenging patients.

Solitary pelvic ectopic kidneys associated with aneurysmal degeneration of the iliac arteries and abdominal aorta are very rare events. Surgical approaches for the correction of aneurysms with renal involvement are challenging due to the lack of current consensus, especially when they are associated with functional solitary pelvic ectopic kidneys. For this reason, one of the strategies that has shown good results in the short- and medium-term is cold nephroprotection, which can be used safely in these patients. In the present case, aortic ectasia with bilateral iliac aneurysms associated with a solitary pelvic ectopic kidney was evidenced in a 75-year-old male patient with arterial hypertension and dyslipidemia. Bilateral aortoiliac reconstruction was performed with hypogastric artery reconstruction and reimplantation of the ectopic renal artery under cold renal irrigation, without complications and with preserved renal function. [ABSTRACT FROM AUTHOR]

Solitary pelvic ectopic kidneys associated with aneurysmal degeneration of the iliac arteries and abdominal aorta are very rare events. Surgical approaches for the correction of aneurysms with renal involvement are challenging due to the lack of current consensus, especially when they are associated with functional solitary pelvic ectopic kidneys. For this reason, one of the strategies that has shown good results in the short and medium term is cold nephroprotection, which can be used safely in these patients. In the present case, aortic ectasia with bilateral iliac aneurysms associated with a solitary pelvic ectopic kidneys was evidenced in a 75-year-old male patient with arterial hypertension and dyslipidemia. Bilateral aortoiliac reconstruction was performed with hypogastric artery reconstruction and reimplantation of the ectopic renal artery under cold renal irrigation, without complications and preservation of renal function. [ABSTRACT FROM AUTHOR]

Background: The objective of the present study was to evaluate the bioresorption rate of collagen coating (CC) sealed on textile vascular grafts (VGs) and their healing in humans using histologic analysis of explanted VGs. Methods: A total of 27 polyester textile VGs had been removed during surgery from 2012 to 2020. The segments underwent histologic assessment. The CC bioresorption rate was assessed using morphometric analysis to determine the internal and external capsule thickness, inflammatory reaction degree, presence of neovessels, and endothelial cell layer. Results: A total of 27 VGs were explanted from 25 patients because of infection (n = 5; 18.5%), thrombosis (n = 7; 25.9%), stenosis (n = 2; 7.4%), rupture (n = 4; 14.8%), aneurysmal degeneration (n = 3; 11.1%), revascularization (n = 4; 14.8%), or another cause (n = 2; 7.4%), with a median implantation duration of 291 days (interquartile range [IQR], 48-911 days). VGs with remaining CC (n = 7; 26%) had been explanted earlier than had those without (n = 20; 74%; 1 day [IQR, 1-45 days] vs 516 days [IQR, 79-2018 days]; P = .001). After 1 year, no remaining CC was detected on the analyzed VG sections. VGs implanted for 90 days. VGs implanted for >90 days had a greater external capsule thickness (889.2 μm [IQR, 39.6-1317 μm] vs 0 μm [IQR, 0-0 μm]; P = .002), a higher number of inflammatory mononuclear cells and giant cells (168 cells [IQR, 110-310 cells] vs 0 cells [IQR, 0-94 cells]; P < .0001) and a higher number of neovessels (4 [IQR, 0-5] vs 0 [IQR, 0-0]; P = .001) than those implanted for

Background Non-invasive monitoring of autologous vein graft (VG) bypass grafts is largely limited to detecting late luminal narrowing. Although magnetic resonance imaging (MRI) delineates vein graft intima, media, and adventitia, which may detect early failure, the scan time required to achieve sufficient resolution is at present impractical. Purpose To study VG visualization enhancement in vivo and delineate whether a covalently attached MRI contrast agent would enable quicker longitudinal imaging of the VG wall. Material and Methods Sixteen 12-week-old male C57BL/6J mice underwent carotid interposition vein grafting. The inferior vena cava of nine donor mice was treated with a gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA)-based contrast agent, with control VGs labeled with a vehicle. T1-weighted (T1W) MRI was performed serially at postoperative weeks 1, 4, 12, and 20. A portion of animals was sacrificed for histopathology following each imaging time point. Results MRI signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were significantly higher for treated VGs in the first three time points (1.73 × higher SNR, P = 0.0006, and 5.83 × higher CNR at the first time point, P = 0.0006). However, MRI signal enhancement decreased consistently in the study period, to 1.29 × higher SNR and 2.64 × higher CNR, by the final time point. There were no apparent differences in graft morphometric analyses in Masson's trichrome-stained sections. Conclusion A MRI contrast agent that binds covalently to the VG wall provides significant increase in T1W MRI signal with no observed adverse effects in a mouse model. Further optimization of the contrast agent to enhance its durability is required.

Abstract As the global population ages, the issue of abdominal aortic aneurysm continues to grow. With the evolution of new devices and refined operative technique, aneurysm treatment via endovascular aortic repair is becoming increasingly favourable. This, however, is not without drawbacks, where regular surveillance is paramount to long‐term success and detection of post‐procedure complications. Of these complications, endoleak is the most notable and poses the greatest risk of potential future aortic rupture. The purpose of this review paper is to discuss the armada of imaging modalities used in the detection and evaluation of endoleak and their varying usefulness. Plain abdominal X‐ray is a cost‐effective tool in detecting gross graft abnormalities such as stent migration or deformity (kinking or fracture). Though it may raise suspicion for endoleak, X‐ray does not allow accurate classification of endoleak type when used alone. Duplex ultrasonography quantifies both aortic anatomy and real time flow dynamics. Most screening programmes are conducted using two‐dimensional ultrasound. Unfortunately, observer and equipment variability may lead to surveillance discrepancies—but reduced when utilising a dedicated vascular sonography laboratory. Contrast enhanced ultrasonography is a promising alternative to computed tomography, though still is emerging. Computed tomography angiography certainly has disadvantages (ionising radiation, contrast‐nephropathy, limited differentiation of endoleak type)—however, it provides near‐real surgical dimensions and highlights graft complications and concomitant disease (such as neighbouring infection). With widespread availability and short scan time, it certainly remains valuable in surveillance. Magnetic resonance angiography has a similar sensitivity to computed tomography (minus the radiation), however is plagued by movement and metal artefact. Other novel modalities in endoleak surveillance include four‐dimensional ultrasound, multiplanar intra‐operative probes, nuclear medicine and wall stress analysis.

The frozen elephant trunk (FET) technique can be applied to extensive aortic pathology, including lesions in the aortic arch and proximal descending thoracic aorta. FET is useful for tear-oriented surgery in dissections, managing malperfusion syndrome, and promoting positive aortic remodeling. Despite these benefits, complications such as distal stent-induced new entry and spinal cord ischemia can pose serious problems with the FET technique. To prevent these complications, careful sizing and planning of the FET are crucial. Additionally, since the FET technique involves total arch replacement, meticulous surgical skills are essential, particularly for young surgeons. In this article, we propose several techniques to simplify surgical procedures, which may lead to better outcomes for patients with extensive aortic pathology. In the era of precision medicine, the next-generation FET device could facilitate the treatment of complex aortic diseases through a patient-tailored approach.

We report a case of a hybrid aortic debranching procedure for repair of a paravisceral inflammatory aortic aneurysm. Vein grafts were chosen over prosthetics because of concern for infection as a possible etiology. The gonadal vein was successfully used as a vein graft between the right common iliac artery and the right renal artery before aortic endograft placement.

Vascular access-induced limb ischemia is a known complication of arteriovenous fistulas and grafts. Many techniques have been adopted to prevent steal in high-risk patients and to treat steal in cases of moderate ischemia not controlled with conservative management. A major factor guiding treatment is access flow volume. Management is different when ischemia is combined with the excessive flow in contrast to the combination with normal flow. We describe the most popular techniques encountered in the English literature as a part of a stepwise approach to treating dialysis access steal syndrome. In absence of ischemia, when cardiac issues emerge due to extreme access flow volumes, some of these techniques are also used to decrease flow and protect the heart. Patient's history, focused clinical examination, color duplex ultrasound examination, pulse oximetry and an angiogram are essential tools to approach this entity. [ABSTRACT FROM AUTHOR]

ABSTRACT BACKGROUND: Peripheral arterial disease (PAD) is characterized by progressive narrowing of the arterial lumen, resulting from atherosclerotic plaques. Treatment for PAD aims to control atherosclerosis and improve blood flow. Use of antiplatelet agents and anticoagulants has played important roles in helping to prevent occlusions and stenosis. OBJECTIVE: To evaluate the evidence from Cochrane systematic reviews regarding the accuracy, effectiveness and safety of use of anticoagulants and antiplatelets in lower-limb revascularization, in patients with peripheral arterial disease. METHODS: Systematic reviews found through searches in the Cochrane Library were included. Two authors evaluated whether the reviews found were in line with the inclusion criteria for this investigation. A qualitative synthesis of their findings was presented. RESULTS: Three systematic Cochrane reviews were included. Patients who underwent prosthetic bypass surgery probably presented greater benefit from use of antiplatelets, and patients who underwent vein revascularization probably presented greater benefit from use of anticoagulants. Patients who received endovascular treatment benefited from both antiplatelet and anticoagulant treatment. However, the reliability of the results found was impaired because at the time when these reviews were published, there was no mandatory assessment using the GRADE criteria. CONCLUSION: Despite the evidence found, it is necessary for these reviews to be updated in order to evaluate the degree of certainty of the results found.

BACKGROUND: Surgical approach to type A acute aortic dissection (AADA) is usually dictated by the presenting anatomy. We compared long-term outcomes of AADA repaired with a root replacement versus a supracoronary tube graft, regardless of the proximal extent of the intimal tear. METHODS: A single-centre, retrospective cohort of consecutive patients undergoing repair of AADA between December 1999 and March 2012 were stratified based on the proximal surgical procedure performed: supracoronary tube graft or root replacement. Imaging, chart reviews and clinical follow-ups were analyzed to identify the presenting anatomy and clinical outcomes. RESULTS: We included the cases of 75 patients in our analysis: 54 received a supracoronary tube graft and 21 received a root replacement. The proximal tear was identified below the sinotubular junction in all patients in the root group and in 61% of patients in the supracoronary group. We detected no differences between the groups for in-hospital mortality, length of stay, or complications. However, the root group had significantly increased renal failure (0% v. 9.5%, p = 0.018), cardiopulmonary bypass time (198.4 ± 80.0 min v. 316.5 ± 102.5 min, p < 0.001), cross-clamp time (91.6 ± 34.9 min v. 191.3 ± 52.8 min, p < 0.001), duration of surgery (457.5 ± 129.9 min v. 611.6 ± 197.8 min, p < 0.001), and platelet transfusions (8.1 ± 7.6 v. 12.8 ± 8.7 units, p = 0.021) than the supracoronary group. Long-term follow-up demonstrated a greater incidence of 2+ aortic regurgitation among patients in the supracoronary group than the root group (29.7% v. 0.0%, p = 0.006); however, there was no difference between the groups in symptoms or reoperation. CONCLUSION: In AADA, aortic root replacement involves a longer procedure with increased risk of early renal impairment. Long-term follow-up identified significantly more aortic regurgitation and root dilation in the supracoronary group than the root group, with a trend toward worse long-term survival. However, we found no difference between the groups in mortality, reoperation or New York Heart Association class.

Small-diameter synthetic vascular grafts have high failure rate due to primarily surface thrombogenicity, and effective surface chemical modification is critical to maintain the patency of the grafts. In this study, we engineered a small-diameter, elastic synthetic vascular graft with off-the-shelf availability and anti-thrombogenic activity. Polycarbonate-urethane (PCU), was electrospun to produce nanofibrous grafts that closely mimicked a native blood vessel in terms of structural and mechanical strength. To overcome the difficulty of adding functional groups to PCU, we explored various surface modification methods, and determined that plasma treatment was the most effective method to modify the graft surface with functional amine groups, which were subsequently employed to conjugate heparin via end-point immobilization. In addition, we confirmed in vitro that the combination of plasma treatment and end-point immobilization of heparin exhibited the highest surface density and correspondingly the highest anti-thrombogenic activity of heparin molecules. Furthermore, from an in vivo study using a rat common carotid artery anastomosis model, we showed that plasma-heparin grafts had higher patency rate at 2weeks and 4weeks compared to plasma-control (untreated) grafts. More importantly, we observed a more complete endothelialization of the luminal surface with an aligned, well-organized monolayer of endothelial cells, as well as more extensive graft integration in terms of vascularization and cell infiltration from the surrounding tissue. This work demonstrates the feasibility of electrospinning PCU as synthetic elastic material to fabricate nanofibrous vascular grafts, as well as the potential to endow desired functionalization to the graft surface via plasma treatment for the conjugation of heparin or other bioactive molecules.Statement of significanceVascular occlusion remains the leading cause of death all over the world, despite advances made in balloon angioplasty and conventional surgical intervention. Currently, autografts are the gold-standard grafts used to treat vascular occlusive disease. However, many patients with vascular occlusive disease do not have autologous vascular graft available. Therefore, there is a widely recognized need for a readily available, functional, small-diameter vascular graft (inner diameter of

BackgroundThe erosion of the early mortality advantage of elective endovascular aneurysm repair (EVAR) compared with open repair of abdominal aortic aneurysm remains without a satisfactory explanation.MethodsAn individual-patient data meta-analysis of four multicentre randomized trials of EVAR versus open repair was conducted to a prespecified analysis plan, reporting on mortality, aneurysm-related mortality and reintervention.ResultsThe analysis included 2783 patients, with 14 245 person-years of follow-up (median 5·5 years). Early (0-6 months after randomization) mortality was lower in the EVAR groups (46 of 1393 versus 73 of 1390 deaths; pooled hazard ratio 0·61, 95 per cent c.i. 0·42 to 0·89; P = 0·010), primarily because 30-day operative mortality was lower in the EVAR groups (16 deaths versus 40 for open repair; pooled odds ratio 0·40, 95 per cent c.i. 0·22 to 0·74). Later (within 3 years) the survival curves converged, remaining converged to 8 years. Beyond 3 years, aneurysm-related mortality was significantly higher in the EVAR groups (19 deaths versus 3 for open repair; pooled hazard ratio 5·16, 1·49 to 17·89; P = 0·010). Patients with moderate renal dysfunction or previous coronary artery disease had no early survival advantage under EVAR. Those with peripheral artery disease had lower mortality under open repair (39 deaths versus 62 for EVAR; P = 0·022) in the period from 6 months to 4 years after randomization.ConclusionThe early survival advantage in the EVAR group, and its subsequent erosion, were confirmed. Over 5 years, patients of marginal fitness had no early survival advantage from EVAR compared with open repair. Aneurysm-related mortality and patients with low ankle : brachial pressure index contributed to the erosion of the early survival advantage for the EVAR group. Trial registration numbers: EVAR-1, ISRCTN55703451; DREAM (Dutch Randomized Endovascular Aneurysm Management), NCT00421330; ACE (Anévrysme de l'aorte abdominale, Chirurgie versus Endoprothèse), NCT00224718; OVER (Open Versus Endovascular Repair Trial for Abdominal Aortic Aneurysms), NCT00094575.

Bypass grafting is an established treatment method for coronary artery disease. Graft patency continues to be the Achilles heel of saphenous vein grafts. Research models for bypass graft failure are essential for a better understanding of pathobiological and pathophysiological processes during graft patency loss. Large animal models, such as pigs or sheep, resemble human anatomical structures but require special facilities and equipment. This video describes a rat vein interposition model to investigate vein graft patency loss. Rats are inexpensive and easy to handle. Compared to mouse models, the convenient size of rats permits better operability and enables a sufficient amount of material to be obtained for further diverse analysis. In brief, the inferior epigastric vein of a donor rat is harvested and used to replace a segment of the femoral artery. Anastomosis is conducted via single stitches and sealed with fibrin glue. Graft patency can be monitored non-invasively using duplex sonography. Myointimal hyperplasia, which is the main cause for graft patency loss, develops progressively over time and can be calculated from histological cross sections.

Chronic limb-threatening ischemia is rarely associated with previous traumatic injury. We present a case of a 28-year-old male with progressive digit ulcers, a weak pulse, cyanosis, and a cold limb. Eight months prior, he had a motorcycle accident resulting in a right clavicle fracture and brachial plexus injury. Computed tomography angiography revealed occlusion of the right subclavian artery near a surgically implanted reduction plate. The patient underwent an open subclavian-brachial bypass with a reversed saphenous vein graft. His postoperative recovery was uneventful. After 3 months, he had a euthermic right hand with a palpable pulse and his ulcers had completely healed. This case reinforces the need for patients with a neurological deficit in the upper extremity caused by blunt trauma to undergo thorough vascular examination to identify potential arterial injury and compromised perfusion.

Surgical resection remains the best choice for the treatment of liver tumors. Hepatectomy combined with artificial vascular reconstruction has been proven as an alternative to treating tumors involving the main hepatic veins. As the cutting-edge surgical technique, robotic liver surgery is a novel procedure expanding the field of minimally invasive approaches, especially in complex reconstruction. This study reports, for the first time, on a robotic hepatectomy with middle hepatic vein (MHV) reconstruction using an expanded polytetrafluoroethylene (ePTFE) graft for a patient with hepatic adenoma. The tumor, which was located in segment 8, was adjacent to the MHV. Robot-assisted resection of segment 4 and partial segment 8, and MHV reconstruction using a ePTFE graft were performed. During the post-operative examination and follow-up, the blood flow of the ePTFE graft was patent, and liver function recovered well. Thus, robotic hepatectomy with MHV reconstruction is a safe, minimally invasive, and precise surgery that may provide a novel approach for patients with liver tumors that are invading or adjacent to the main hepatic veins.

We report a case of successful open repair of a 7.5-cm juxtarenal abdominal aortic aneurysm (AAA) in the presence of a left-sided inferior vena cava (LS-IVC) crossing the aorta at the level of the renal arteries in a 72-year-old man. The orifice of the right renal artery was slightly caudal to that of the left renal artery and concomitant occlusive diseases of both iliac arteries were present. Based on the imaging and intraoperative findings, repair of the juxtarenal AAA was performed with mobilization of the LS-IVC, which was encircled twice with soft silicone rubber vessel loops on both sides of operating field and the blood content of the LS-IVC was temporarily evacuated. This procedure allowed proximal control with inter-renal clamping of the aorta and placement of an aortobifemoral polytetrafluoroethylene graft.

Inadequate vein quality or prior harvest precludes use of autologous single segment greater saphenous vein (ssGSV) in many patients with chronic limb-threatening ischemia (CLTI). Predictors of patient outcome after infrainguinal bypass with alternative (non-ssGSV) conduits are not well-understood. We explored whether limb presentation, bypass target, and conduit type were associated with amputation-free survival (AFS) after infrainguinal bypass using alternative conduits. A single-center retrospective study (2013-2020) was conducted of 139 infrainguinal bypasses performed for CLTI with cryopreserved ssGSV (cryovein) (n = 71), polytetrafluoroethylene (PTFE) (n = 23), or arm/spliced vein grafts (n = 45). Characteristics, Wound, Ischemia, and foot Infection (WIfI) stage, and outcomes were recorded. Multivariable Cox proportional hazards and classification and regression tree analysis modeled predictors of AFS. Within 139 cases, the mean age was 71 years, 59% of patients were male, and 51% of cases were nonelective. More patients undergoing bypass with cryovein were WIfI stage 4 (41%) compared with PTFE (13%) or arm/spliced vein (27%) (P =.04). Across groups, AFS at 2 years was 78% for spliced/arm, 79% for PTFE, and 53% for cryovein (adjusted hazard ratio for cryovein, 2.5; P =.02). Among cases using cryovein, classification and regression tree analysis showed that WIfI stage 3 or 4, age >70 years, and prior failed bypass were predictive of the lowest AFS at 2 years of 36% vs AFS of 58% to 76% among subgroups with less than two of these factors. Although secondary patency at 2 years was worse in the cryovein group (26% vs 68% and 89% in arm/spliced and PTFE groups; P <.01), in patients with tissue loss there was no statistically significant difference in wound healing in the cryovein group (72%) compared with other bypass types (72% vs 87%, respectively; P =.12). In patients with CLTI lacking suitable ssGSV, bypass with autogenous arm/spliced vein or PTFE has superior AFS compared with cryovein, although data were limited for PTFE conduits for distal targets. Despite poor patency with cryovein, wound healing is achieved in a majority of cases, although it should be used with caution in older patients with high WIfI stage and prior failed bypass, given the low rates of AFS. [ABSTRACT FROM AUTHOR]

ABSTRACT The Fistula First Breakthrough Initiative, founded in 2003, was responsible for changing the access profile in the United States, increasing the prevalence of arteriovenous fistulas (AVFs) by 50% and reducing that of arteriovenous grafts (AVGs). However, the concept that AVFs are always the best access for all patients has been challenged. Discussion points are: (1) the questionable survival benefit of AVFs over AVGs, if one takes into account the high rates of primary AVF failure; (2) the potential benefits of using AVGs for greater primary success; and (3) the questionable benefit of AVFs over AVGs in patients with shorter survival, such as the elderly. The high rate of primary failure and maturation procedures leads to prolonged use of catheters, and it is one of the weaknesses of the fistula first strategy. AVGs proved to be better than AVFs as a second access after the failure of a first AVF, and in patients with non-ideal vessels, with greater primary success and reduced catheter times. AVGs appear to have a similar survival to AVFs in patients older than 80 years, with less primary failures and interventions to promote maturation. The most recent KDOQUI guidelines suggest an individualized approach in access planning, taking into account life expectancy, comorbidities and individual vascular characteristics, with the aim of chosing adequate access for the right patient, at the right time, for the right reasons.

A 47-year-old male with Leriche syndrome presented with digital gangrene due to TASC II type-D occlusion of the distal aorta and common iliac arteries. Open revascularization was performed using a Dacron aorto-biiliac bypass graft; however, the postoperative course revealed a nondisclosed history of intravenous opioid abuse as he went into withdrawal psychosis. Our report highlights ways to mitigate infection risk associated with prosthetic aortic grafts in suspected or confirmed intravenous drug abusers. The literature review suggests alternative strategies like aortoiliac endarterectomy, total endovascular approach using non-covered stents, or a hybrid approach. The primary use of autologous venous grafts should be considered as a last resort so that the veins are retained for future use in case of graft infection. Patient factors like comorbidities, fitness to undergo surgery, anatomical extent of occlusion, and availability of facilities/expertise can further guide the management plan owing to a lack of evidence-based guidelines.

Limb ischemia is a known complication of vascular access that may appear early postoperatively or after years. Over the last few decades, various techniques based on different physiological mechanisms have been used for treatment. A standardized treatment does not exist, and must be individualized based on the flow volume, and the type and location of the access. True and false vascular access aneurysms are another common complication of arteriovenous fistulas, which develop because of venous hypertension or repeated needling. Evidence in the literature regarding treatment of patients with steal syndrome and concomitant true arteriovenous aneurysms is scarce. A female with a brachiocephalic fistula complicated by steal syndrome and vascular access aneurysms was treated successfully with tapered graft placement and aneurysm exclusion.

BACKGROUND: U.S. hemodialysis patients with systemic lupus erythematosus (SLE) and end-stage renal disease (ESRD) are less likely than other ESRD patients to have a permanent vascular access (fistula or graft) in place at the dialysis start. We examined whether vascular access outcomes after dialysis start differed for SLE vs. other ESRD patients. METHODS: Among U.S. patients initiating hemodialysis in 2010 with only a catheter (n = 40,911; 384 with SLE) and using a permanent access on first dialysis (n = 13,073; 48 with SLE), we examined the association of SLE status with time to first placement of a permanent access (among catheter-only patients) and to loss of access patency (among patients using a permanent access on first dialysis), both censored 1 year after dialysis start, using multivariable Cox proportional hazards models. RESULTS: Among catheter-only patients, 46.1 % vs. 54.5 % of those with SLE-ESRD vs. other ESRD had a permanent access placed within 1 year after dialysis start. However, with adjustment, there was no association of 1-year placement with SLE status [HR = 1.00 (95 % CI, 0.86-1.17)]. SLE-ESRD vs. other ESRD patients starting dialysis with a permanent access were less likely to experience a 1-year loss of patency (43.8 % vs. 55.0 %), but this association was not statistically significant after adjustment [HR = 0.88 (0.57-1.37)]. CONCLUSION: These results suggest that SLE-ESRD patients starting dialysis with a catheter are not more likely to have a permanent access placed in the first year of dialysis, despite an observed lack of association of SLE status with subsequent loss of vascular access patency among those starting dialysis with a permanent access.

OBJECTIVE: Approximately 30% of autogenous vein grafts develop luminal narrowing and fail because of intimal hyperplasia or negative remodeling. We previously found that vein graft cells from patients who later develop stenosis proliferate more in vitro in response to growth factors than cells from patients who maintain patent grafts. To discover novel determinants of vein graft outcome, we have analyzed gene expression profiles of these cells using a systems biology approach to cluster the genes into modules by their coexpression patterns and to correlate the results with growth data from our prior study and with new studies of migration and matrix remodeling. METHODS: RNA from 4-hour serum- or platelet-derived growth factor (PDGF)-BB-stimulated human saphenous vein cells obtained from the outer vein wall (20 cell lines) was used for microarray analysis of gene expression, followed by weighted gene coexpression network analysis. Cell migration in microchemotaxis chambers in response to PDGF-BB and cell-mediated collagen gel contraction in response to serum were also determined. Gene function was determined using short-interfering RNA to inhibit gene expression before subjecting cells to growth or collagen gel contraction assays. These cells were derived from samples of the vein grafts obtained at surgery, and the long-term fate of these bypass grafts was known. RESULTS: Neither migration nor cell-mediated collagen gel contraction showed a correlation with graft outcome. Although 1188 and 1340 genes were differentially expressed in response to treatment with serum and PDGF, respectively, no single gene was differentially expressed in cells isolated from patients whose grafts stenosed compared with those that remained patent. Network analysis revealed four unique groups of genes, which we term modules, associated with PDGF responses, and 20 unique modules associated with serum responses. The yellow and skyblue modules, from PDGF and serum analyses, respectively, correlated with later graft stenosis (P = .005 and P = .02, respectively). In response to PDGF, yellow was also associated with increased cell growth. For serum, skyblue was also associated with inhibition of collagen gel contraction. The hub genes for yellow and skyblue (ie, the gene most connected to other genes in the module), scavenger receptor class A member 5 (SCARA5) and suprabasin (SBSN), respectively, were tested for effects on proliferation and collagen contraction. Knockdown of SCARA5 increased proliferation by 29.9% ± 7.8% (P < .01), whereas knockdown of SBSN had no effect. Knockdown of SBSN increased collagen gel contraction by 24.2% ± 8.6% (P < .05), whereas knockdown of SCARA5 had no effect. CONCLUSIONS: Using weighted gene coexpression network analysis of cultured vein graft cell gene expression, we have discovered two small gene modules, which comprise 42 genes, that are associated with vein graft failure. Further experiments are needed to delineate the venous cells that express these genes in vivo and the roles these genes play in vein graft healing, starting with the module hub genes SCARA5 and SBSN, which have been shown to have modest effects on cell proliferation or collagen gel contraction.

Vascular graft infection (VGI) is a feared complication. Prevention is of the utmost importance and vascular graft coatings (VGCs) could offer a potential to do this, with in vitro research a first crucial step. The aim of this study was to summarise key features of in vitro models investigating coating strategies to prevent VGI in order to provide guidance for the setup of future translational research. A comprehensive search was performed in MEDLINE, Embase, and Web of Science. A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. For each database, a specific search strategy was developed. Quality was assessed with the Toxicological data Reliability Assessment Tool (ToxRTool). In vitro models using a VGC and inoculation of the graft with a pathogen were included. The type of graft, coating, and pathogen were summarised. The outcome assessment in each study was evaluated. In total, 4 667 studies were identified, of which 45 papers met the inclusion criteria. The majority used polyester grafts (68.2%). Thirty-one studies (68.9%) included antibiotics, and nine studies (20%) used a commercial silver graft in their protocol. New antibacterial strategies (e.g., proteolytic enzymes) were investigated. A variety of testing methods was found and focused mainly on bacterial adherence, coating adherence and dilution, biofilm formation, and cytotoxicity. Ninety-three per cent of the studies (n = 41) were considered unreliable. Polyester is the preferred type of graft to coat on. The majority of coating studies are based on antibiotics; however, new coating strategies (e.g., antibiofilm coating) are coming. Many in vitro setups are available. In vitro studies have great potential, they can limit the use, but cannot replace in vivo studies completely. This paper can be used as a guidance document for future in vitro research. [ABSTRACT FROM AUTHOR]

As the global population ages, the issue of abdominal aortic aneurysm continues to grow. With the evolution of new devices and refined operative technique, aneurysm treatment via endovascular aortic repair is becoming increasingly favourable. This, however, is not without drawbacks, where regular surveillance is paramount to long‐term success and detection of post‐procedure complications. Of these complications, endoleak is the most notable and poses the greatest risk of potential future aortic rupture. The purpose of this review paper is to discuss the armada of imaging modalities used in the detection and evaluation of endoleak and their varying usefulness. Plain abdominal X‐ray is a cost‐effective tool in detecting gross graft abnormalities such as stent migration or deformity (kinking or fracture). Though it may raise suspicion for endoleak, X‐ray does not allow accurate classification of endoleak type when used alone. Duplex ultrasonography quantifies both aortic anatomy and real time flow dynamics. Most screening programmes are conducted using two‐dimensional ultrasound. Unfortunately, observer and equipment variability may lead to surveillance discrepancies—but reduced when utilising a dedicated vascular sonography laboratory. Contrast enhanced ultrasonography is a promising alternative to computed tomography, though still is emerging. Computed tomography angiography certainly has disadvantages (ionising radiation, contrast‐nephropathy, limited differentiation of endoleak type)—however, it provides near‐real surgical dimensions and highlights graft complications and concomitant disease (such as neighbouring infection). With widespread availability and short scan time, it certainly remains valuable in surveillance. Magnetic resonance angiography has a similar sensitivity to computed tomography (minus the radiation), however is plagued by movement and metal artefact. Other novel modalities in endoleak surveillance include four‐dimensional ultrasound, multiplanar intra‐operative probes, nuclear medicine and wall stress analysis. [ABSTRACT FROM AUTHOR]

To determine differences in outcomes among patients undergoing ipsilateral carotid bypass with hostile or normal neck anatomy. Single-center retrospective review of all ipsilateral extracranial carotid bypasses performed between 1998 and 2018. Forty-eight patients underwent ipsilateral carotid bypass from the common carotid artery to either the internal carotid artery or carotid bifurcation during the study period. Seven patients were excluded owing to either a lack of follow-up or missing data. The indications for intervention included infected patches, aneurysmal degeneration, symptomatic and asymptomatic stenosis or restenosis, carotid body tumors, neck malignancy, and trauma. In 25 procedures (61%), there was a hostile neck anatomy defined as a prior history of external beam neck irradiation or neck surgery. Among this group, 12 pectoralis muscle flaps were performed for reconstructive coverage. Conduits included polytetrafluorethylene (n = 21), great saphenous vein (n = 9), superficial femoral artery (n = 7) and arterial homograft (n = 4). All superficial femoral artery conduits were used in the hostile neck group (P =.03). The overall mean time of follow-up was 22 months, with all bypasses remaining patent with no significant clinical stenosis. The 30-day ipsilateral stroke and myocardial infarction rates were 4.88% each, all within the hostile neck group, with no 30-day mortalities for the entire cohort. One-third of the muscle flaps were performed in the setting of infected patches (P =.02) with no significant differences in perioperative outcomes with use. The overall median hospital length of stay was significantly increased in patients receiving muscle flap coverage (3.0 vs 7.0 days; P =.04). In patients with a complex carotid pathology, ipsilateral carotid bypass is an effective solution for carotid reconstruction. Different conduits should be used depending on the indication. Muscle flap coverage should be considered in hostile settings when primary wound closure is not feasible. [ABSTRACT FROM AUTHOR]