Vein Bypass Research Articles

Visceral Artery Aneurysms: A 40-Year Experience from a Single Center.

Visceral artery aneurysms (VAAs) are a relatively uncommon phenomenon, occurring all types of VAA at an incidence of 0.01% to 0.2%. The present study aims to describe the clinical characteristics, and treatment outcomes of patients with VAAs treated at a Chilean academic institution over the past 40 years. Single center retrospective study of patients with VAAs surgically treated between August 1982 and May 2023. Data encompassing patient demographics, aneurysm characteristics, treatment modalities, and outcomes were analyzed. The cohort included 59 patients with 64 aneurysms, predominantly female (n=35, 59.3%) with a median age of 51 years (range: 21-86 years). The most common VAAs were localized in the renal (n=32, 50.0%) and splenic arteries (n=20, 31.3%). Endovascular procedures were performed in 27 (42.2%) cases, and open surgery in 37 (57.8%) cases. Two (3.1%) cases were treated with renal autotransplantation, aneurysmectomy was performed in three (4.7%) cases, prosthetic bypass in 10 cases (15.6%), and vein bypass in 22 cases (34.4%). Embolization was employed in 21 cases (32.8%), covered stenting in 5 cases (7.8%), and one case (1.6%) received both embolization and stenting. Technical success was 100% in the endovascular group vs. 97.0% in the open group (p=0.387). Overall, the complication rate was 6.7% (n=4) with a 30-day mortality rate of 2.1% (n=1). Median follow-up was 60.5 months (6-318 months), with a long-term mortality rate of 5.0% (n=3). Patients operated on during the first time frame era, before the endovascular era, (1982-2002) had larger aneurysms than those operated on in the second time frame (2003-2023), with a median size of 30 mm versus 23 mm, respectively (p < 0.04). In the present study, both open repair and endovascular repair had similar surgical outcomes; however, the shift seen over time towards endovascular interventions aligns with current trends favoring less invasive procedures.

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

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. 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. 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. 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. 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.

Cephalic to jugular vein bypass surgery of subclavian vein stenosis for arteriovenous fistula salvage in maintenance hemodialysis patients.

Ipsilateral subclavian vein stenosis in a well-functioning upper extremity arteriovenous fistula (AVF) is a significant factor contributing to AVF failure and sometimes swelling of ipsilateral upper extremity. Graft bypass surgery can alleviate outflow tract stenosis in upper extremity AVF, restore function, and efficiently relieve arm swelling. The present study aimed to evaluate patency and postoperative complications after cephalic to jugular graft bypass surgery in patients with upper extremity AVF failure or upper extremity swelling on the same side of the AVF resulting from ipsilateral subclavian vein stenosis. Five patients with upper extremity AVF and ipsilateral subclavian vein stenosis undergoing maintenance hemodialysis were included. Three patients had AVF dysfunction, while two experienced swelling of the arm due to high venous pressure in the AVF. The surgical procedure involved creating a subcutaneous tunnel in the shoulder to connect a 6 mm polytetrafluorethylene (PTFE) graft, from either near the fistula site (n = 3) or at the mid-upper arm cephalic vein (n = 2), to the jugular vein. Graft bypass surgery was successful, and all patients were able to resume hemodialysis postoperatively. Upper extremity edema improved, without any postoperative wound infections, non-healing wounds, steal syndrome, or high-flow AVF leading to heart failure as a complication. Five to 19 months after surgery, the bypass grafts exhibited a primary patency rate of 100%, and vascular access fulfilled the requirements for hemodialysis. Cephalic to jugular vein bypass surgery for upper extremity AVF with ipsilateral subclavian vein stenosis effectively preserved function of the original fistula, and was associated with few postoperative complications.

Immunohistochemical Localization of Fibroblast Activation Protein in Coronary Arteries with Different Forms of Atherosclerosis.

Background: Fibroblast activation protein (FAP) is a cell surface glycoprotein expressed by myofibroblasts in areas of active tissue remodeling. It plays a potentially important role in cardiac remodeling, atherosclerotic plaque formation, and plaque rupture. Given the distinct pathophysiology and morphology of different forms of atherosclerosis, we analyzed FAP expression in human coronary vessels with no coronary artery disease, atherosclerotic plaques at different levels of progression, and other distinct forms of coronary disease in post bypass vein grafting and cardiac allograft vasculopathy after a heart transplant. Methods: Immunohistochemical staining with monoclonal F19 mouse anti-human FAP antibody was performed to identify FAP in human atherosclerotic plaques, coronary bypass atherosclerosis, and post-transplant arteriosclerosis. The presence and distribution of FAP in different types and stages of human atherosclerosis were compared. Results: There was no FAP staining in patients with no significant coronary disease. All different types of human atherosclerotic lesioning lesions showed the presence of FAP expression, with different staining patterns in advanced atherosclerotic plaque, vein graft atherosclerosis lesions, and arteriosclerosis after a heart transplant. Conclusions: These data suggest that FAP may be a potential diagnostic marker and target for interventions, not only in coronary atherosclerotic plaque, but also in other forms of coronary disease, which have distinct pathophysiologies and currently limited treatment options.

Mid-Term Results of Popliteal-Pedal Inframalleolar Vein Bypasses in Chronic Limb-Threatening Ischemia Patients After Previous Failed Tibial Endovascular Recanalization

Inframalleolar bypass still preserves its role in the modern endovascular era. Aim of this study was to evaluate the mid-term outcomes of "short" inframalleolar vein bypasses in patients with chronic limb-threatening ischemia (CLTI) after the previously failed tibial endovascular recanalization. Between January 2015 and December 2021,107 CLTI patients in 3 Italian Departments of Vascular Surgery underwent "short" inframalleolar vein bypass after failed tibial endovascular recanalization. Early (30-day) and 3-year outcomes were evaluated in terms of survival, primary patency, primary assisted patency, secondary patency, and amputation-free survival. Univariate analysis of the perioperative factors affecting outcomes were performed by the means of log-rank test. The associations of procedure variables were sought based on a multivariate Cox regression analysis. Distal anastomosis (inframalleolar) was mostly performed on dorsal pedis (64, 59.8%). At 30days, bypass occlusion was recorded in 5 cases (4.6%). The mean follow-up period was 20.5±17.9months. The estimated 3-year overall survival was 66.7%. Three-year estimates of primary patency, primary assisted patency, secondary patency, and amputation-free survival were 68.5%, 70.1%, 70.2%, and 76.7%, respectively. Multivariate analysis showed a negative association of insulin treatment with primary patency (HR 4.3, P=0.04), primary assisted patency (HR 5.1, P=0.02), and secondary patency (HR 5.1, P=0.02). The negative association of long-term corticosteroid use was also found with primary patency (HR 7.8, P=0.005), primary assisted patency (HR 8.7, P=0.003), secondary patency (HR 8.7, P=0.003), and amputation-free survival (HR 3.9, P=0.05). Short" vein bypasses to the foot arteries in CLTI patients yielded good mid-term overall patency and limb salvage rates after a failed tibial endovascular recanalization. Insulin-dependent diabetes mellitus and long-term corticosteroid use seemed to affect the outcomes.

Vein bypass first vs. best endovascular treatment first revascularisation strategy for chronic limb-threatening ischaemia due to infra-popliteal disease: the BASIL-2 RCT.

Chronic limb-threatening ischaemia with ischaemic pain and/or tissue loss. To examine the clinical and cost-effectiveness of a vein bypass-first compared to a best endovascular treatment-first revascularisation strategy in preventing major amputation or death. Superiority, open, pragmatic, multicentre, phase III randomised trial. Thirty-nine vascular surgery units in the United Kingdom, and one each in Sweden and Denmark. Patients with chronic limb-threatening ischaemia due to atherosclerotic peripheral arterial disease who required an infra-popliteal revascularisation, with or without an additional more proximal infra-inguinal revascularisation procedure, to restore limb perfusion. A vein bypass-first or a best endovascular treatment-first infra-popliteal, with or without an additional more proximal infra-inguinal revascularisation strategy. The primary outcome was amputation-free survival. Secondary outcomes included overall survival, major amputation, further revascularisation interventions, major adverse limb event, health-related quality of life and serious adverse events. Participants were randomised to a vein bypass-first or a best endovascular treatment-first revascularisation strategy. The original sample size of 600 participants (247 events) was based on a hazard ratio of 0.66 with amputation-free survival rates of 0.72, 0.62, 0.53, 0.47 and 0.35 in years 1-5 in the best endovascular treatment-first group with 90% power and alpha at p = 0.05. The sample size was revised to an event-based approach as a result of increased follow-up time due to slower than anticipated recruitment rates. Participants were followed up for a minimum of 2 years. A cost-effectiveness analysis was employed to estimate differences in total hospital costs and amputation-free survival between the groups. Additionally, a cost-utility analysis was carried out and the total cost and quality-adjusted life-years, 2 and 3 years after randomisation were used. Between 22 July 2014 and 30 November 2020, 345 participants were randomised, 172 to vein bypass-first and 173 to best endovascular treatment-first. Non-amputation-free survival occurred in 108 (63%) of 172 patients in the vein bypass-first group and 92 (53%) of 173 patients in the best endovascular treatment-first group [adjusted hazard ratio 1.35 (95% confidence interval 1.02 to 1.80); p = 0.037]. Ninety-one (53%) of 172 patients in the vein bypass-first group and 77 (45%) of 173 patients in the best endovascular treatment-first group died [adjusted hazard ratio 1.37 (95% confidence interval 1.00 to 1.87)]. Over follow-up, the economic evaluation discounted results showed that best endovascular treatment-first was associated with £1690 less hospital costs compared to vein bypass-first. The cost utility analysis showed that compared to vein bypass-first, best endovascular treatment-first was associated with £224 and £2233 less discounted hospital costs and 0.016 and 0.085 discounted quality-adjusted life-year gain after 2 and 3 years from randomisation. Recruiting patients to the Bypass versus Angioplasty in Severe Ischaemia of the Leg Trial-2 trial was difficult and the target number of events was not achieved. A best endovascular treatment-first revascularisation strategy was associated with better amputation-free survival, which was largely driven by fewer deaths. Overall, the economic evaluation results suggest that best endovascular treatment-first dominates vein bypass-first in the cost-effectiveness analysis and cost-utility analysis as it was less costly and more effective than a vein bypass-first strategy. The Bypass versus Angioplasty in Severe Ischaemia of the Leg Trial-2 investigators have a data sharing agreement with the BEst Surgical Therapy in patients with Chronic Limb threatening Ischaemia investigators. One output of this collaboration will be an individual patient data meta-analysis. Current Controlled Trials ISRCTN27728689. This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 12/35/45) and is published in full in Health Technology Assessment; Vol. 28, No. 65. See the NIHR Funding and Awards website for further award information.

Long-Term Outcomes of Elective Endovascular versus Open Repair of Popliteal Artery Aneurysms in the VISION Database

IntroductionThe best modality for elective popliteal artery aneurysm repair (PAR) remains controversial. Most single center studies suggest open popliteal aneurysm repair (OPAR) is more durable than endovascular (EPAR), but large randomized multicenter studies are lacking. This study compares long-term outcomes of EPAR and OPAR in the VQI-VISION database. MethodsVascular Quality Initiative (VQI) Medicare-linked VISION database (2010-2019) for peripheral vascular interventions and infrainguinal bypass were reviewed for elective PAR. Patients undergoing OPAR and EPAR were propensity-matched to compare outcomes. ResultsThere were 1,159 PAA repairs (65.1% open). EPAR patients were older (77 vs 73 years, p<0.001) and more likely to be on P2Y12 inhibitors (26.5% vs 17.0%, p<0.001). After matching, there were 396 patients in each group with similar baseline characteristics. EPAR patients were more likely to be discharged home (87.6% vs 48.5%, p<0.001) and have shorter hospital length-of-stay (1 vs 3 days, p<0.001). Kaplan-Meier curves showed no difference in mortality, reintervention, or major amputation at 1, 3, and 5 years. Cox proportional hazards regression showed no significant association between revascularization strategy and mortality, reintervention, or major amputation. Subgroup analysis of patients undergoing OPAR with great saphenous vein (GSV) bypass compared to EPAR showed that OPAR with GSV bypass was associated with lower mortality without difference in reintervention or major amputation. ConclusionElective EPAR is durable and comparable to OPAR in terms of limb outcomes, even when GSV is used as conduit. However, bypass with GSV was associated with increased survival after open popliteal aneurysm repair compared to endovascular therapy.

Renal nutcracker syndrome presenting with varicocele: A case series

Introduction and importanceNutcracker syndrome (NCS) is a rare condition characterized by left renal vein compression and presents with diverse clinical manifestations. This case series study aims to evaluate the clinical presentations and outcomes of patients with NCS and varicocele. Case presentationWe reviewed the cases of four male patients, aged 15 to 19 years, who presented with recurrent and grade 3 varicocele after varicocelectomy. All patients reported pain in the hypogastric, flank, or groin areas. Despite the absence of hematuria, NCS was diagnosed based on duplex ultrasound and contrast-enhanced computed tomography (CT) scans. Patients underwent open surgical interventions, including gonadal vein transposition or saphenous vein bypass. Clinical discussionThe absence of hematuria in these cases poses a diagnostic challenge, as current diagnostic criteria for NCS relies on its presence. Our findings underscore the need to consider NCS in patients with varicocele, even in the absence of hematuria. Surgical interventions were effective in resolving the symptoms. After NCS surgery, the varicocele in one patient resolved, and three patients underwent varicocelectomy successfully without recurrence throughout the recovery period. ConclusionThis case series highlights the diagnosis of NCS presenting with varicocele and local pain without hematuria, emphasizing the need for improved diagnostic and management approaches.

Ultrasound-guided drainage of a popliteal ganglion cyst extending to the adventitia of the popliteal artery: a case report of cystic adventitial disease of synovial origin.

We report a case of a 67-year-old woman suffering from intermittent claudication secondary to severe popliteal stenosis due to compression by a popliteal ganglion cyst extending into the adventitia of the popliteal artery. After declining vein bypass grafting, this patient was successfully treated using ultrasound-guided aspiration of the cyst, which restored normal flow to the popliteal artery. Whilst aspiration of Baker's cysts causing claudication has been attempted before, this represents the first reported case of successful recanalization of the popliteal artery by ganglion cyst aspiration and further supports an important possible aetiology and treatment for cystic adventitial disease.

Role of Multistate Models to Predict Patency, Limb Salvage, and Survival: New Concepts to Analyse Data in Peripheral Arterial Disease

In peripheral arterial disease, patency, limb salvage, and survival rates are mostly reported using Kaplan-Meier analyses. When comparing different revascularisation techniques, these methods have limitations in analysing complex patient flows over time. This study aimed to present, illustrate, and discuss new concepts based on multistate models of analysing outcome parameters in peripheral arterial disease. Previously published data from a single centre, randomised controlled trial (RCT) with 218 cases that underwent either vein bypass surgery (bypass group, n= 109) or nitinol stent angioplasty (stent group, n= 109) of long femoropopliteal lesions were re-analysed using non-homogeneous Markov models. A step by step description of the concepts of states, state space, definitions, and illustration of transition probability curves as well as the benefits of multistate models is given. The RCT was registered at ISRCTN.com (ISRCTN18315574). Transition probability curves over time showed similar patterns in the bypass and stent groups. Significant differences in the transition probabilities were found for transitions from primary patency as well as secondary patency to end of patency. The transition probability for patients with preserved primary patency at 24 months who moved to end of patency at 48 months was 19.9% in the stent group vs. 6.4% in the bypass group (p < .001). The proposed method can answer important questions, such as: Did patients after femoropopliteal stenting with preserved primary patency at two years lose their patency more quickly within the following years compared with bypass surgery? And did stent patients after a re-intervention to maintain patency at one year lose their patency more quickly compared with bypass surgery within the following years? Completely new research questions can now be raised and answered to optimise treatment and follow up strategies; this might lead to better identification of subgroups at higher risk of clinical deterioration following revascularisation procedures.

Comparative outcomes between cryopreserved cadaveric saphenous vein and spliced autogenous vein for infrainguinal bypass

Objective Cryopreserved greater saphenous vein (CV) and spliced autogenous veins (SV) serve as alternative conduits for lower extremity revascularization when a single-segment autogenous saphenous vein is not available. This study compares the outcomes of infrainguinal bypasses using CV and two-segment SV as conduits. Methods We conducted a retrospective review of data on all lower extremity bypasses performed using CV or SV at our institution. Patients undergoing revascularization for atherosclerotic occlusive disease were included in the statistical analysis, while those with primary acute embolic and/or traumatic causes were excluded. Primary outcomes included limb loss. Secondary outcomes included primary, primary assisted, and secondary patency at one and 3 years. Results 56 patients were included in the analysis, 25 had CV bypass and 31 had SV. The groups did not significantly differ in demographics and comorbidities except for age (mean age 68 CV vs 62 SV, p = .03), and prior coronary artery bypass graft (32% CV vs 6.5% SV, p = .01). There was no statistically significant difference between CV and SV at one- and three-years in limb salvage (54.4% CV vs 61.7% SV, p = .96 and 48.3% CV vs 50.2% SV, p = .94), and bypass abandonment (44.2% CV vs 61.7% SV, p = .83 and 44.2% CV vs 44% SV, p = .85). Despite lower one and 3-year primary patency for CV compared to SV (33.3% CV vs 54.9% SV, p = .29, and 27.7% CV vs 48% SV, p = .27), the difference was statistically not significant. CV and SV had also similar one and 3-year primary assisted (41.8% CV vs 57.8% SV, p = .72 and 41.8% CV vs 44.9% SV, p = .71), and secondary patency (43.9% CV vs 61.7% SV, p = .8 and 43.9% CV vs 44% SV, p = .88), with no statistically significant difference. Conclusion In patients for whom single-segment autologous saphenous vein bypass is not an option, CV and SV show comparable limb salvage up to 3 years. SV may be a more durable option with higher patency, this was however not statistically significant in our cohort likely due to sample size.

Contemporary Outcomes of Infrainguinal Vein Bypass Surgery for Chronic Limb-Threatening Ischaemia: A Two-Centre Cross-Sectional Study.

Background/Objectives: Chronic limb-threatening ischaemia (CLTI) is a significant life and limb-threatening condition. Two recent seminal trials, BEST-CLI and BASIL-2, have provided seemingly conflicting results concerning the optimal treatment modality for patients with CLTI. We sought to investigate the outcomes of patient undergoing infrainguinal bypass at two centres in Aotearoa New Zealand. Methods: A cross-sectional retrospective review of all patients who underwent infrainguinal bypass grafting for CLTI at Auckland City Hospital and Waikato Hospital between January 2020 and December 2021 was performed. The primary outcome was a composite of death, above-ankle amputation, and major limb reintervention. The secondary outcome was minor limb reintervention. Kaplan-Meier survival analysis was performed to determine time to the primary and secondary endpoints. Demographic factors were examined using the log-rank test to examine the effect on the outcome. Results: One hundred and nineteen patients who underwent infrainguinal bypass for CLTI in the study period were identified. Of these, 93 patients had a bypass with ipsilateral or contralateral GSV. The median follow-up time was 1.85 years. The most common indication for surgery was tissue loss (69%, n = 63), with the most common distal bypass target being the below-knee popliteal artery (45%, n = 41). The primary composite outcome occurred in 42.8% of the cohort (n = 39). Death was the most common component of the primary outcome (26%, n = 24). Male sex (HR 0.48, 95% CI 0.26-0.88, p = 0.018) and statin use (HR 0.49, 95% CI 0.24-0.98, p = 0.044) were independent predictors of protection from the composite outcome on multivariate analysis. Dialysis dependence (HR 3.32, 95% CI 1.23-8.99, p = 0.018) was an independent predictor for patients meeting the composite outcome. Conclusions: This study's results are consistent with the published outcomes of BEST-CLI. The patient cohorts examined, anatomical disease patterns, and conduit use may explain some of the differences observed between this study, BEST-CLI and BASIL-2. Further work is required to define the specific patient populations who will benefit most from an open surgical or endovascular first approach to the management of CLTI.

Medium-to Long-term Outcomes of Rex Shunt in 105 Children With Extrahepatic Portal Vein Obstruction in China

PurposeThe aim of our study was to analyze the medium-to long-term outcomes of Rex shunts in a large series of children with extrahepatic portal vein obstruction (EHPVO). MethodsThe clinical data of 105 children aged between 6 months and 16 years with EHPVO who underwent Rex shunt between October 2014 and June 2021 at our center were retrospectively reviewed after more than 2 years of follow-up. ResultsThe overall patency rate of the Rex shunt was 91.43% (96/105) during a median follow-up of 41 months (range, 24–98 months). Eighty-seven (82.86%) of the 105 patients underwent classical Rex shunt with internal jugular vein (IJV) bypass, and the remaining 18 patients (17.14%) underwent modified Rex shunt with intra-abdominal vein bypass. Patients with a patent shunt experienced portal hypertension resolution, which was characterized by a reduction in portal pressure, disappearance of variceal bleeding, relief of gastroesophageal varices, and relief of splenomegaly or hypersplenism. The rate of Rex shunt thrombosis in our center was 8.57% (9/105), and a repeat Rex shunt was effective for the treatment of graft thrombosis. Anastomotic stenosis occurred in 14.26% (15/105) of the children, 38.46% (5/13) of whom received successful endovascular intervention therapy and experienced remission of portal hypertension symptoms. The patency rate of the classical Rex shunt was higher than that of the modified Rex shunt (97.70% vs. 61.11%), whereas the rate of vascular complications, including anastomotic stenosis and graft thrombosis, of the classical Rex shunt was lower than that of the modified Rex shunt (11.49% vs. 77.78%). Further comparison revealed that the risk of vascular complications was substantially greater in the modified Rex shunt group than in the classical Rex shunt group in the nonadjusted model, minimally adjusted model, and fully adjusted model (RR ranged from 6.77 to 7.07, all p < 0.001). ConclusionsThe Rex shunt provides medium-to long-term benefits for children with EHPVO. The classical Rex shunt with IJV bypass provides the best patency rate and the fewest vascular complications. Levels of EvidenceⅢ Type of StudyRetrospective comparative study.

Femoro-popliteal bypass versus remote endarterectomy: a propensity matched analysis.

The purpose of this study was to compare femoropopliteal bypass (FPB) and remote endarterectomy (RE) for long femoropopliteal lesions. Single center retrospective propensity matching analysis of the symptomatic patients with long occlusion of the femoro-popliteal segment (>250 mm), who underwent femoro-popliteal bypass above the knee or remote endarterectomy from 2014 to 2020. Primary endpoints: primary patency (PP), secondary patency (SP), target lesion revascularization (TLR). Secondary endpoints: MALE, MACE, clinical improvement and survival. Four hundred patients were divided into two groups: 200 in the FPB group and 200 in the RE group. As a result of propensity score matching, 110 (FPB) and 109 (RE) patients remained. Three-year primary patency rates were 62% for FPB vs. 53% for RE, P=0.16. Secondary patency rates were 84% for FPB vs. 75% for RE, P=0.10. Freedom from TLR were 61% for FPB vs. 71% for RE P=0.21. Survival and amputation-free survival (AFS) also did not differ (93% vs. 94%, P=0.81 and 87% vs. 92%, P=0.19 respectively). Primary patency of the GSV higher than RE (P=0.00) and PTFE (P=0.00). It was established statistically advantages of RE and great saphenous vein (GSV) bypass over a PTFE bypass in SP (P=0.01 P=0.03), TLR (P=0.02 P=0.00) and AFS (P=0.03 P=0.01). Surgical treatment of long femoropopliteal occlusions with an autovenous bypass or remote endarterectomy showed significantly better results in secondary patency, TLR and AFS than the use of PTFE prostheses. GSV remains the gold standard for femoropopliteal bypass surgery.

Beyond the Rex: an innovative meso-intrahepatic portal vein bypass for late-onset extrahepatic portal vein occlusion after living donor liver transplantation.

The Meso-Rex bypass (MRB) is recognized as an effective treatment for portal hypertension secondary to extrahepatic portal vein occlusion (EHPVO) both in the pediatric and adult population, within or outside the context of liver transplantation. It is the preferred surgical treatment in most centers because not only does it addresses the portal hypertension, but also restores physiologic portal hepatopetal flow. However, the Rex recess, the landmark for this technique, may not be safely accessible in some patients. We present a 22-year-old male who underwent living donor liver transplant (LDLT) for neonatal hepatitis. He presented with variceal bleeding due to EHPVO at 13 years after transplant. Various endoscopic, radiologic, and surgical interventions were employed to address the recurrent gastrointestinal bleeding, but results have been unsatisfactory. We performed a meso-intrahepatic portal vein bypass (MIPVB), an innovative alternative to the MRB, for this patient with extensive post-operative adhesions, perihilar collaterals, and cavernous transformation. MIPVB creation in patients where the Rex recess is inaccessible is technically challenging. But with a multidisciplinary team approach, meticulous preoperative planning, and close follow-up, the authors have demonstrated that it is a safe and feasible option for patients with late-onset EHPVO after liver transplantation.

Application of flow-through flaps for replantation after traumatic limb amputation according to the angiosome concept.

This study was performed to explore the treatment of the injury caused by traumatic limb amputation. From October 2002 to October 2021, 30 cases were enrolled in the present study. The reasons for injury were as follows: 8 cases with single hydraulic column crush injury, 12 cases with gear and wire rope stranding, 6 cases with belt avulsion injury, and 4 cases with carbon block smash injury. The present study application of a free or small saphenous vein bypass to reconstruct the injured artery and vein according to the concept of the angiosome model. The defective vessels were bridged with the axial vessels of a flow-through flap, such as a medial calf flap or anterolateral femoral flap, to construct an additional blood supply and drainage vein for the severed limb. The clinical data of 30 cases with traumatic limb amputation of the lower leg and ankle were retrospectively analyzed. In all 30 cases of traumatic limb amputation, the replantation via the adoption of a flow-through flap was successful, and 85.6% of the patients remained in good postoperative condition. There were no symptoms of ischemia in the marginal segment after blood supply reconstruction of the transected limb by axial vascular bridging within the flap. Via the adoption of microsurgical techniques, the blood supply to the transected limb can be reconstructed by bridging the defective vessels with the adoption of the axial vessels of the flow-through flap is a feasible and advanced treatment option.

Comparison of the mechanical properties of bypass grafts: Experimental assays.

One prevalent therapeutic strategy for addressing atherosclerosis is using an alternative blood supply route to the heart, referred to as bypass surgery. In these surgeries, the saphenous vein, radial artery, and internal mammary artery are commonly used to create this bypass route. Unfortunately, due to negligence regarding the compatibility of the graft with the host tissue, reoperation is often required after several years. One method that can aid in selecting a suitable vein for bypass is simulating the solid-fluid interaction, and performing such simulations requires knowledge of the mechanical properties of bypass grafts. Therefore, extracting the mechanical properties of bypass grafts is essential. In this study, human bypass grafts were subjected to uniaxial tensile testing, and their elastic modulus was extracted and compared. Additionally, the hyperelastic properties of these grafts were extracted using the Mooney-Rivlin model for use in numerical software. The average elastic modulus in the circumferential direction for radial artery, mammary artery, and saphenous vein samples were determined to be 1.384 ± 0.268MPa, 3.108 ± 1.652MPa, and 7.912 ± 2.509MPa, respectively. Based on the results of uniaxial tests, the saphenous vein exhibited the highest stiffness among the three vascular tissues. The mechanical characterization results of the bypass vessels can be applied to the clinical studies of heart diseases. They may help develop an appropriate treatment approach.

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

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. 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. 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 30day mortality rate was 2.4% (n = 1) and the overall 30day 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 5years 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 5years were 90.1%, 74.5%, and 70.9%, respectively. 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.

FGL2/FcγRIIB Signalling Mediates Arterial Shear Stress-Mediated Endothelial Cell Apoptosis: Implications for Coronary Artery Bypass Vein Graft Pathogenesis.

The sudden exposure of venous endothelial cells (vECs) to arterial fluid shear stress (FSS) is thought to be a major contributor to coronary artery bypass vein graft failure (VGF). However, the effects of arterial FSS on the vEC secretome are poorly characterised. We propose that analysis of the vEC secretome may reveal potential therapeutic approaches to suppress VGF. Human umbilical vein endothelial cells (HUVECs) pre-conditioned to venous FSS (18 h; 1.5 dynes/cm2) were exposed to venous or arterial FSS (15 dynes/cm2) for 24 h. Tandem Mass Tagging proteomic analysis of the vEC secretome identified significantly increased fibroleukin (FGL2) in conditioned media from HUVECs exposed to arterial FSS. This increase was validated by Western blotting. Application of the NFκB inhibitor BAY 11-7085 (1 µM) following pre-conditioning reduced FGL2 release from vECs exposed to arterial FSS. Exposure of vECs to arterial FSS increased apoptosis, measured by active cleaved caspase-3 (CC3) immunocytochemistry, which was likewise elevated in HUVECs treated with recombinant FGL2 (20 ng/mL) for 24 h under static conditions. To determine the mechanism of FGL2-induced apoptosis, HUVECs were pre-treated with a blocking antibody to FcγRIIB, a receptor FGL2 is proposed to interact with, which reduced CC3 levels. In conclusion, our findings indicate that the exposure of vECs to arterial FSS results in increased release of FGL2 via NFκB signalling, which promotes endothelial apoptosis via FcγRIIB signalling. Therefore, the inhibition of FGL2/FcγRIIB signalling may provide a novel approach to reduce arterial FSS-induced vEC apoptosis in vein grafts and suppress VGF.

Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL)-2 Trial: Analysis of the Timing and Causes of Death in Participants Randomised to an Infrapopliteal Vein Bypass or Best Endovascular Treatment First Revascularisation Strategy

The Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL)-2 trial enrolled participants with chronic limb threatening ischaemia who required an infrapopliteal, with or without a femoropopliteal, revascularisation procedure to restore limb perfusion. Participants randomised to a vein bypass (VB) first revascularisation strategy were over one third more likely than those randomised to a best endovascular treatment (BET) first revascularisation strategy to die from any cause during a median follow up of 40.0 (interquartile range 20.9, 60.6) months. The aim of the present study was to describe the timing and causes of death in BASIL-2 as a first step towards trying to better understand why randomisation to a VB first revascularisation strategy was associated with this excess mortality. A 10 person international panel comprising vascular and endovascular surgeons as well as vascular interventional radiologists, who had all been principal investigators in BASIL-2, took part in a modified Delphi consensus exercise to adjudicate the primary cause of death and, in particular, whether the cause was primarily cardiac or non-cardiac. In 151 of 168 deaths (89.9%), the Delphi panel achieved a consensus regarding the cause of death being probably cardiac or non-cardiac. In the BET group, 16 of 77 deaths (21%) were classified as probably cardiac compared with 32 of 91 (35%) in the VB group (unadjusted subdistribution hazard ratio 2.16, 95% confidence interval [CI] 1.20 - 3.87; unadjusted cause specific hazard ratio 2.15, 95% CI 1.19 - 3.90). At the point of randomisation, 64 of 344 (18.6%), 40 of 342 (11.7%), and 37 of 344 (10.8%) participants had a previous myocardial infarction (MI), percutaneous coronary intervention (PCI), and coronary artery bypass graft (CABG), respectively. There was no evidence of varying treatment effects for cause of death in subgroup analyses of previous PCI, CABG, or MI. The excess mortality observed in the VB first revascularisation strategy group in BASIL-2 was largely due to deaths that were adjudicated by the Delphi panel as probably primarily cardiac. These excess cardiac deaths were observed throughout follow up and there was no evidence of non-proportional hazards. Further work is ongoing to try to better understand the reasons for these findings.