Drug-coated balloons versus conventional percutaneous transluminal angioplasty for treatment-naïve dysfunctional arteriovenous fistulas.: A 10-year single center retrospective study.

OBJECTIVES: To compare the primary patency and restenosis rates in treatment naieve dialysis arteriovenous fistulas (AVFs) after drug-coated balloons (DCB) versus plain balloon angioplasty (PTA). METHODS: This retrospective study included 157 patients who underwent AVF angioplasty for treatment-native AVF stenosis between January 2012 to 2022. The fistulas were Brachiocephalic (75%), Brachiobasilic (17%), and radiocephalic (8%). The index intervention was with either DCB or percutaneous transluminal angioplasty (PTA) with subsequent follow up. Patients with central venous stenosis, thrombosed fistula, fistula stents, AV graft or surgical intervention after the index procedure were excluded. RESULTS: Arteriovenous fistula angioplasty was done in 28 patients using DCB and in 129 patients using PTA. A total of 108 patients presented with a single stenosis, 42 with 2 stenoses, and 7 with 3 stenoses. The location of these stenoses was in the venous outflow (57%), the juxta anastomotic segment (31%), and cephalic arch (12%). The median time to re-intervention for the PTA was 216 days compared to 304 days for the DCB (p=0.079). Primary patency at 6 months was 60.4% for PTA and 75% for DCB (p=0.141) CONCLUSION: Although DCB angioplasty of treatmentnaïve dysfunctional AVF tends to improve the time to intervention and 6-month primary patency compared to PTA, this difference did not reach statistical significance.

Retrospective evaluation of three types of expanded polytetrafluoroethylene grafts for upper limb vascular access.

Currently, three expanded polytetrafluoroethylene (ePTFE) prosthetic graft types are most commonly used for patients with end-stage kidney disease (ESKD) who require long-term vascular access for hemodialysis. However, studies comparing the three ePTFE grafts are limited. This study compared the clinical efficacy and postoperative complications of three ePTFE prosthetic graft types used for upper limb arteriovenous graft (AVG) surgery among patients with ESKD. Patients with ESKD requiring upper limb AVG surgery admitted to our center between January 2016 and September 2019 were enrolled. Overall, 282 patients who completed the 2-year follow-up were included and classified into the following three groups according to the ePTFE graft type: the GPVG group with the PROPATEN® graft, the GAVG group with the straight-type GORE® ACUSEAL, and the BVVG group with the VENAFLO® II. The patency rate and incidence of access-related complications were analyzed and compared between groups. The patients were followed up postoperatively, and data were collected at 6, 12, 18, and 24 months postoperatively. Respective to these follow-up time points, in the GPVG group, the primary patency rates were 74.29%, 65.71%, 51.43%, and 42.86%; the assisted primary patency rates were 85.71%, 74.29%, 60.00%, and 48.57%; and the secondary patency rates were 85.71%, 80.00%, 71.43%, and 60.00%. In the GAVG group, the primary patency rates were 73.03%, 53.93%, 59.42%, and 38.20%; the assisted primary patency rates were 83.15%, 68.54%, 59.55%, and 53.93%; and the secondary patency rates were 85.39%, 77.53%, 68.54%, and 62.92%, respectively. In the BVVG group, the primary patency rates were 67.24%, 53.45%, 41.38%, and 29.31%; the assisted primary patency rates were 84.48%, 67.24%, 55.17%, and 44.83%; and the secondary patency rates were 86.21%, 81.03%, 68.97%, and 60.34%, respectively. The differences in patency rates across the three grafts were not statistically significant. Overall, 18, 4, and 12 patients in the GPVG, GAVG, and BVVG groups, respectively, experienced seroma. Among the three grafts, GORE® ACUSEAL had the shortest anastomosis hemostatic time. The first cannulation times for the three grafts were GPVG at 16 (±8.2), GAVG at 4 (±4.9), and BVVG at 18 (±12.7) days. No significant difference was found in the postoperative swelling rate between the GPVG group and the other two groups. Furthermore, no statistically significant differences were found across the three graft types regarding postoperative vascular access stenosis and thrombosis, ischemic steal syndrome, pseudoaneurysm, or infection. In conclusion, no statistically significant differences in the postoperative primary, assisted primary, or secondary graft patency rates were observed among the three groups. A shorter anastomosis hemostatic time, first cannulation time, and seroma occurrence were observed with the ACUSEAL® graft than with its counterparts. The incidence of upper extremity swelling postoperatively was greater with the PROPATEN® graft than with the other grafts. No statistically significant differences were observed among the three grafts regarding the remaining complications.

Pathohistomorphometric and Immuno-Histologic Changes in Early Arteriovenous Fistula Failure in Patients with Chronic Kidney Disease.

BACKGROUND: Hemodialysis is a prevalent treatment for the end-stage chronic kidney disease (CKD) worldwide. The primary arteriovenous fistula (AVF), widely considered the optimal hemodialysis access method, fails to mature in up to two-thirds of the cases. The etiology of the early AVF failure, defined as thrombosis or inability to use within three months post-creation remains less understood, and is influenced by various factors including patient demographics, surgical techniques, and genetic predispositions. Neointimal hyperplasia is a primary histological finding in stenotic lesions leading to the AVF failure. However, there are insufficient data on the cellular phenotypes and the impact of the preexisting CKD-related factors. This study aims to investigate the histological, morphometric, and immunohistochemical alterations in the fistula vein, pre-, peri-, and post-early failure. MATERIALS AND METHODS: Eighty-nine stage 4-5 CKD patients underwent standard preoperative assessment, including the Doppler ultrasound, before a typical radio-cephalic AVF creation. Post-failure, a new AVF was created proximally. The vein specimens were collected during the surgery, processed, and analyzed for morphometric analyses and various cellular markers, including Vimentin, TGF, and Ki 67. RESULTS: The study enrolled 89 CKD patients, analyzing various aspects of their condition and AVF failures. The histomorphometric analysis revealed substantial venous luminal stenosis and varied endothelial changes. The immunohistologic analysis showed differential marker expressions pre- and post-AVF creation. CONCLUSION: This study highlights the complexity of the early AVF failures in CKD patients. The medial hypertrophy emerged as a significant preexisting lesion, while the postoperative analyses indicated a shift towards neointimal hyperplasia. The research underscores the nuanced interplay of vascular remodeling, endothelial damage, and cellular proliferation in the AVF outcomes.

Graft Patency and Clinical Outcomes in Patients With Radial Artery Grafts Previously Instrumented for Cardiac Catheterization.

BACKGROUND: While transradial access is favored for cardiac catheterization, the radial artery (RA) is increasingly preferred for coronary artery bypass grafting. Whether the RA is suitable for use as a graft following instrumentation for transradial access remains uncertain. METHODS: Consecutive patients from 2015 to 2019 who underwent coronary artery bypass grafting using both the left and right RAs as grafts were included. Instrumented RAs underwent careful preoperative assessment for suitability. The clinical analysis was stratified by whether patients received an instrumented RA graft (instrumented versus noninstrumented groups). Eligible patients with both instrumented and noninstrumented RAs underwent computed tomography coronary angiography to evaluate graft patency. The primary outcome was a within-patient paired analysis of graft patency comparing instrumented to noninstrumented RA grafts. RESULTS: Of the 1123 patients who underwent coronary artery bypass grafting, 294 had both the left and right RAs used as grafts and were included. There were 126 and 168 patients in the instrumented and noninstrumented groups, respectively. Baseline characteristics and perioperative outcomes were comparable. The rate of major adverse cardiac events at 2 years following coronary artery bypass grafting was 2.4% in the instrumented group and 5.4% in the noninstrumented group (hazard ratio, 0.44 [95% CI, 0.12-1.61]; P=0.19). There were 50 patients included in the graft patency analysis. At a median follow-up of 4.3 (interquartile range, 3.7-4.5) years, 40/50 (80%) instrumented and 41/50 (82%) noninstrumented grafts were patent (odds ratio, 0.86 [95% CI, 0.29-2.52]; P>0.99). No significant differences were observed in the luminal diameter or cross-sectional area of the instrumented and noninstrumented RA grafts. CONCLUSIONS: There was no evidence found in this study that RA graft patency was affected by prior transradial access, and the use of an instrumented RA was not associated with worse outcomes in the exploratory clinical analysis. Although conduits must be carefully selected, prior transradial access should not be considered an absolute contraindication to the use of the RA as a bypass graft. REGISTRATION: URL: https://www.anzctr.org.au/; Unique identifier: ACTRN12621000257864.

Clinical outcomes and predictive factors of stent grafts treatment for symptomatic central venous obstruction in end stage kidney disease patients with arteriovenous access.

To assess the efficacy of stent grafts (SGs) in managing central venous obstruction disease (CVOD) in hemodialysis (HD) patients with arteriovenous (AV) access, and to identify predictive factors influencing the SG treatment outcomes. HD subjects with CVOD who underwent SGs placement at our center between August 2018 and June 2022 were enrolled. Survival curve analysis using the Kaplan-Meier method and log-rank test was performed. Cox proportional hazards regression analysis was employed to identify predictive factors associated with outcomes. A total of 59 SG implantation procedures for CVOD were analyzed, comprising 30 cases of stenosis and 29 cases of occlusion. The access circuit primary patency (ACPP) at 6, 12, and 24 months post-SG placement were 80.9%, 53.8%, and 31.4%, respectively, while, the target lesion primary patency (TLPP) were 91.3%, 67.6%, and 44.5%, respectively. Subgroup analysis revealed higher TLPP in the stenosis group compared to the occlusion group, although the difference was not statistically significant (P = 0.165). The TLPP was significantly improved by SG placement in those who had antecedent balloon dilations (P < 0.001). Cox proportional hazards regression identified target lesion length ≥ 30 mm and procedure defects as independent predictors of lower TLPP after SG treatment for CVOD in HD patients. SG placement demonstrates safety and efficacy in managing CVOD among HD patients, leading to improved TLPP of endovascular therapy (EVT) for CVOD. Notably, long target lesions (≥ 30 mm) and procedure defects emerged as predictive factors influencing TLPP.

Descriptive Analysis of Amputation-Free Survival After First Time Infra-Inguinal Bypass Occlusion.

INTRODUCTION: Occlusion after infra-inguinal bypass surgery for peripheral artery disease is a major complication with potentially devastating consequences. In this descriptive analysis, we sought to describe the natural history and explore factors associated with long-term major amputation-free survival following occlusion of a first-time infra-inguinal bypass. METHODS: Using a prospective database from a tertiary care vascular center, we conducted a retrospective cohort study of all patients with peripheral artery disease who underwent a first-time infra-inguinal bypass and subsequently suffered a graft occlusion (1997-2021). The primary outcome was longitudinal rate of major amputation-free survival after bypass occlusion. Cox proportional hazard models were used to generate hazard ratios (HRs) and 95% confidence intervals (CIs) to explore predictors of outcomes. RESULTS: Of the 1318 first-time infra-inguinal bypass surgeries performed over the study period, 255 bypasses occluded and were included in our analysis. Mean age was 66.7 (12.6) years, 40.4% were female, and indication for index bypass was chronic limb threatening ischemia (CLTI) in 89.8% (n = 229). 48.2% (n = 123) of index bypass conduits used great saphenous vein, 29.0% (n = 74) prosthetic graft, and 22.8% (n = 58) an alternative conduit. Median (interquartile range) time to bypass occlusion was 6.8 (2.3-19.0) months, and patients were followed for median of 4.3 (1.7-8.1) years after bypass occlusion. Following occlusion, 38.04% underwent no revascularization, 32.94% graft salvage procedure, 25.1% new bypass, and 3.92% native artery recanalization. Major amputation-free survival following occlusion was 56.9% (50.6%-62.8%) at 1 y, 37.1% (31%-43.3%) at 5 y, and 17.2% (11.9%-23.2%) at 10 y. In multivariable analysis, factors associated with lower amputation-free survival were older age, female sex, advanced cardiorenal comorbidities, CLTI at index procedure, CLTI at time of occlusion, and distal index bypass outflow. Initial treatment after occlusion with both a new surgical bypass (HR 0.44, CI: 0.29-0.67) or a graft salvage procedure (HR 0.56, CI: 0.38-0.82) showed improved amputation-free survival. One-year rate of major amputation or death were 59.8% (50.0%-69.6%) for those who underwent no revascularization, 37.9% (28.7%-49.0%) for graft salvage, and 26.7% (17.6%-39.5%) for new bypass. CONCLUSIONS: Long-term major amputation-free survival is low after occlusion of a first-time infra-inguinal bypass. While several nonmodifiable risk factors were associated with lower amputation-free survival, treatment after graft occlusion with either a new bypass or a graft salvage procedure may improve longitudinal outcomes.

Sharp needle reconstructs peripheral outflow for patients with malfunctional arteriovenous fistula.

OBJECTIVE: To investigate the feasibility and efficacy of combining ultrasound-guided sharp needle technique with percutaneous transluminal angioplasty (PTA) for treating outflow stenosis or dysfunction in arteriovenous fistula (AVF) among hemodialysis patients. METHODS: From October 2021 to March 2023, patients with occluded or malfunctional fistula veins not amenable to regularly angioplasty were retrospectively enrolled in the study. They underwent ultrasound-guided sharp needle intervention followed by PTA. Data on the location and length between the two veins, technical success, clinical outcomes, and complications were collected. Patency rates post-angioplasty were calculated through Kaplan-Meier analysis. RESULTS: A total of 23 patients were included. The mean length of the reconstructed extraluminal segment was 3.18 cm. The sharp needle opening was performed on the basilic vein (60.9%), brachial vein (26.1%), or upper arm cephalic vein (13%) to create outflow channels. Postoperatively, all cases presented with mild subcutaneous hematomas around the tunneling site and minor diffuse bleeding. The immediate patency rate for the internal fistulas was 100%, with 3-month, 6-month, and 12-month patency rates at 91.3%, 78.3%, and 43.5%, respectively. CONCLUSION: Sharp needle technology merged with PTA presents an effective and secure minimally invasive method for reconstructing the outflow tract, offering a new solution for recanalizing high-pressure or occluded fistulas.

Rationale and design of a single-center randomized trial to compare the graft patency between the radial artery and the no-touch saphenous vein in coronary artery bypass grafting surgery (GRAFT-CAB Study).

BACKGROUND: Previous studies suggested only the radial artery and the No-touch (NT) technique were effective in reducing graft occlusion after coronary artery bypass grafting (CABG) surgery. However, there is no randomized trial comparing these 2 graft conduits. The optimum second conduit for CABG remains undetermined. MATERIALS AND METHODS: This study is a prospective, single-center randomized clinical trial, aiming to compare the graft patency between the radial artery and the NT vein graft. All patients undergoing isolated CABG with left internal mammary artery (LIMA) plus at least 2 additional grafts will be considered eligible. About 774 cases (516 in the radial artery group and 258 in the NT vein group) will be enrolled in over 1 to 2 years. Participants will be randomized and allocated to two bypass strategies: the LIMA plus 1 radial artery and 1 conventional vein graft, or the LIMA plus 2 NT vein grafts. The primary outcome is graft occlusion at 1 year after CABG evaluated by CT angiography. The secondary outcomes include graft occlusion at 3 and 5 years and major adverse cardiac or cerebrovascular events at 1, 3, and 5 years follow-ups. DISCUSSION: This study will define whether or not the NT vein has a lower graft occlusion rate than the radial artery in short and mid-term follow-ups, and provide new evidence for the second conduit choice in CABG surgery. TRIAL REGISTRATION: ClinicalTrials.gov NCT06014047. Registered on October 15th, 2023.

Hemodynamics and Wall Mechanics of Vascular Graft Failure.

Blood vessels are subjected to complex biomechanical loads, primarily from pressure-driven blood flow. Abnormal loading associated with vascular grafts, arising from altered hemodynamics or wall mechanics, can cause acute and progressive vascular failure and end-organ dysfunction. Perturbations to mechanobiological stimuli experienced by vascular cells contribute to remodeling of the vascular wall via activation of mechanosensitive signaling pathways and subsequent changes in gene expression and associated turnover of cells and extracellular matrix. In this review, we outline experimental and computational tools used to quantify metrics of biomechanical loading in vascular grafts and highlight those that show potential in predicting graft failure for diverse disease contexts. We include metrics derived from both fluid and solid mechanics that drive feedback loops between mechanobiological processes and changes in the biomechanical state that govern the natural history of vascular grafts. As illustrative examples, we consider application-specific coronary artery bypass grafts, peripheral vascular grafts, and tissue-engineered vascular grafts for congenital heart surgery as each of these involves unique circulatory environments, loading magnitudes, and graft materials.

Rejoining Veins for Forced Maturation of Small-Caliber Arteriovenous Fistula.

BACKGROUND: To evaluate the efficacy of rejoining mainstream and accessory veins for forced maturation of autogenous arteriovenous fistula (AVF). METHODS: Twenty-three patients who underwent forced maturation through vein rejoining between January 2018 and September 2022 were included. In cases where AVF maturation failure due to the presence of accessory veins, rejoining was primarily considered when distinguishing the main branch becomes challenging. This difficulty typically occurs when the sizes of the 2 vessels are nearly equal and the combined diameters of these veins exceed 6 mm. RESULTS: The mean age and follow-up duration were 57.39 ± 16.22 years and 965.65 ± 573.42 days, respectively. Rejoining of both arterial and venous cannulation sites was performed in 11 patients (47.8%), and rejoining of only the venous cannulation site or only the arterial cannulation site was performed in 11 patients (47.8%) and 1 patient (4.3%), respectively. The mean vein size was 0.35 ± 0.06 cm before rejoining and 0.69 ± 0.07 cm after surgery, indicating a significant increase in size (P < 0.01), whereas the flow did not change significantly following rejoining surgery. Maturation and cannulation success was 100%. The 1-year primary patency rate after surgery was 82.0%. During the follow-up period, 34.8% of the patients required additional percutaneous transluminal angioplasty to maintain patency, and 2 patients (11.8%) had stenosis in the rejoined section. CONCLUSIONS: Rejoining surgery is an effective method for achieving AVF maturation in patients with accessory veins when identification of the mainstream vein is difficult, and this method may be considered when achieving maturation by sacrificing 1 vein is expected to be challenging.

A Systematic Review and Meta-Analysis of Heparin-Bonded Expanded Polytetrafluoroethylene Grafts for Below-The-Knee Femoral Bypass Surgery.

BACKGROUND: Heparin-bonded expanded polytetrafluoroethylene (hb-ePTFE) synthetic grafts are an alternative to autologous vein grafts (AVG) for surgical bypass interventions in lower limb peripheral arterial disease (LLPAD). However, the clinical benefits of hb-ePTFE grafts have not been reviewed systematically for patients undergoing below-the-knee (BK) surgical bypass. This study aimed to meta-analyze available data on the utility of hb-ePTFE in patients undergoing BK surgical bypass. METHODS: Medline, Embase, and Cochrane databases were searched, restricted to material in English with no date restriction. In addition, proceedings from relevant congresses were screened going back 2 years. The search was performed in December 2021. Eligible studies included prospective or retrospective comparative studies or prospective single-arm cohorts with an hb-ePTFE arm. Methodological quality was assessed with the ROBINS-I criteria. Outcomes included primary patency, amputation/limb salvage, and overall survival. Clinical outcomes were expressed as event rates. Studies were compared using meta-analysis to generate a standardized mean event rate for each outcome, with its 95% confidence interval (95% CI), using a random-effects model. RESULTS: Following deduplication, 10,263 records were identified and 261 were assessed as full texts. No prospective comparative studies were identified. The level of evidence was uniformly low. Seventeen publications describing data from 9 individual patient cohorts met the inclusion criteria. These cohorts included a total of 1,452 patients undergoing BK surgical bypass with hb-ePTFE. The primary patency rate was 78.9% [95% CI: 72.2-85.7%] at 1 year, 68.2% [95% CI: 62.8-73.6%] at 2 years, decreasing to 48.0% [95% CI: 27.3-68.7%] at 5 years. The secondary patency rate was 84.8% [95% CI: 77.0-92.5%] at 1 year and 68.9% [95% CI: 43.0-94.9%] at 3 years; the 1-year limb salvage rate was 88.3% [95% CI: 79.6-97.1%] at 1 year and 79.0% [95% CI: 56.7-100%] at 3 years. CONCLUSIONS: In patients undergoing BK bypass surgery, hb-ePTFE synthetic grafts, compared to uncoated grafts, perform well for patency and limb salvage. However, the quality of the evidence is low, and well-performed randomized clinical trials are needed to inform clinical decision-making on the choice of synthetic graft.

Glycemic Variability as a Predictor of Graft Failure Following Infrainguinal Bypass for Peripheral Arterial Disease: A Retrospective Cohort Study.

BACKGROUND: Glycemic variability (GV), measured as the change in visit-to-visit glycated hemoglobin (HbA1c), increases the risk of multiple adverse outcomes. However, the impact of GV on graft patency following infrainguinal bypass (IIB) is unknown. A retrospective cohort study was undertaken to assess the impact of GV on graft patency. METHODS: A 3-year single-center retrospective case notes analysis of all people undergoing IIB between 2017 and 2019. Rutherford stage, graft conduit, level of bypass, procedure details, baseline demographics, comorbidities, and GV were assessed. Time to reintervention, ipsilateral amputation, or death was recorded to determine primary patency (PP). RESULTS: One hundred six IIB outcomes were analyzed: mean (± standard deviation) age 68.0 (9.2) years; 69 (65.1%) male, 37 (33.9%), 75 (70.8%) had diabetes mellitus; and 46 (43.4%) underwent elective procedures. GV > 9.1% was associated with significantly lower median PP than GV < 9.1%, 198 (97-753.5) vs. 713 (166.5-1,044.5) days (P = 0.045). On univariate analysis, GV > 9.1% vs. < 9.1% was significantly associated with PP (hazard ratio [HR] 1.85 [confidence interval {CI} 1.091-3.136], P = 0.022). Bypass level was also a univariate predictor, with below knee bypasses (HR 2.31 [CI 1.164-4.564], P = 0.017), and tibial (HR 2.00 [CI 1.022-3.090], P < 0.043) having lower PP than above knee bypasses. On multivariate adjustment, GV > 9.1% and level of bypass remained independent predictors of PP, HR 1.96 (95% CI: 1.12-3.42, P = 0.018) and HR 2.54 (95% CI: 1.24-5.22, P = 0.011), respectively. CONCLUSIONS: GV is an independent predictor of PP following infrainguinal bypass, thus optimizing GV should be a therapeutic target.

Five-Year Experience of Interwoven Self-Expanding Stent Implantation in Stenotic Kinking of Below the Knee Prosthetic Bypasses.

PURPOSE: The purpose of this study was to evaluate the 5-year real-world results of Supera stent implantation in below the knee prosthetic bypasses (BKPBs). All the procedures were performed because of a history of recurrent thrombosis of the graft and significant stenotic kinking of the prosthesis during knee flexion. A Supera stent was implanted to prevent the next potential BKPB thrombosis. MATERIALS AND METHODS: Fourteen patients were included in this single-center, retrospective observational cohort study. All patients underwent Supera stent implantation in infrainguinal prosthetic bypass between 2012 and 2017, due to a history of recurrent thrombosis and kinking of the prosthetic bypass. RESULTS: Prior to Supera stent implantation procedure, all the patients had more than one episode of acute limb ischemia caused by thrombosis of the BKPB. The median number of BKPB thromboses prior to Supera stent implantation was 3 and ranged from 2 to 6. Technical success was achieved in all cases. Primary patency rates at 12, 24, 36 and 60 months were 71.4%, 57.1%, 57.1% and 14.3%, respectively. Secondary patency rates at 12, 24, 36 and 60 months were 78.6%, 64.3%, 64.3% and 35.7%, respectively. One stent fracture was reported during 60-month follow-up. Major amputation was performed in 6 patients in 5-year follow-up. CONCLUSION: Supera stent in treatment of recurrent thrombosis of BKBP is a safe procedure with acceptable mid-term results. However, larger and comparable prospective studies are needed for broader analysis of this procedure.

Omentin reduces venous neointimal hyperplasia in arteriovenous fistula through hypoxia-inducible factor-1 alpha inhibition.

Arteriovenous fistula (AVF) failure often involves venous neointimal hyperplasia (VNH) driven by elevated hypoxia-inducible factor-1 alpha (HIF-1α) in the venous wall. Omentin, known for its anti-inflammatory and anti-hyperplasia properties, has an uncertain role in early AVF failure. This study investigates omentin's impact on VNH using a chronic renal failure (CRF) rabbit model. The CRF rabbit model of AVF received omentin-expressing adenoviral vector or control ß-gal vector to assess omentin's effects on VNH. Human vascular smooth muscle cells (HVSMCs), stimulated with tumor necrosis factor-α (TNF-α), were exposed to recombinant human omentin (Rh-OMT) to study its influence on cell proliferation and migration. The AMP-activated protein kinase (AMPK) inhibitor compound C and the mammalian target of rapamycin (mTOR) activator MHY1485 were employed to explore omentin's mechanisms in VNH reduction through HIF-1α inhibition. Omentin treatment reduced VNH in CRF rabbits, concomitant with HIF-1α down-regulation and the suppression of downstream factors, including vascular endothelial growth factor and matrix metalloproteinases. Rh-OMT inhibited TNF-α-induced HVSMC proliferation and migration by modulating both cell cycle and cell adhesion proteins. Additionally, omentin reduced HIF-1α expression through the AMPK/mTOR pathway activation. Notably, the blockade of AMPK/mTOR signaling reversed omentin-mediated inhibition of VNH, cell proliferation, and migration, both in vivo and in vitro. In conclusion, omentin mitigates VNH post-AVF creation by restraining HIF-1α via AMPK/mTOR signaling. Strategies boosting circulating omentin levels may offer promise in averting AVF failure.

Transjugular approach in aspiration thrombectomy and angioplasty of a thrombosed straight arteriovenous graft compared to the direct hemodialysis access approach.

PURPOSE: To evaluate the efficacy and outcome of the transjugular approach in endovascular recanalization of a thrombosed straight arteriovenous graft (AVG) compared to those of the direct hemodialysis access approach (conventional approach). MATERIALS AND METHODS: We retrospectively assessed patients who underwent aspiration thrombectomy and percutaneous transluminal angioplasty for thrombosed straight AVG performed at a single institution between October 2006 and October 2021. A total of 138 thrombosed AVGs in 83 patients (39 male and 44 females) were divided into the transjugular approach group (Group A) and the conventional approach group (Group B). Technical and clinical success, postintervention primary patency, cumulative patency, and periprocedural complications were compared. RESULTS: There was no statistical difference in demographic data between groups A and B. The technical success rate of group A and B was 96.4% (80/83) and 98.2% 54/55, respectively (p > 0.05). The mean procedure time was 61.4 min (Group A) and 70.5 min (Group B) (p > 0.05). There was no statistically significant difference between the two groups in postintervention primary patency. The cumulative patency of Groups A and B was 911.9 days (range 122-6277) and 1062.3 days (range 72-2302 days), respectively (p > 0.05). One patient in Group B experienced a major graft rupture. Pseudoaneurysm formation at the sheath insertion site occurred in two patients in Group B. No cases of stenosis or thrombosis of the IJV or hematoma at the puncture site were observed in Group A. CONCLUSION: The transjugular approach is as safe and effective as the conventional approach for aspiration thrombectomy and percutaneous transluminal angioplasty of thrombosed straight AVGs.

Pull-through technique through antegrade radial artery puncture without sheath insertion in balloon-assisted radiocephalic arteriovenous fistulas maturation.

PURPOSE: The aim of this study was to investigate the effectiveness and safety of the pull-through technique through antegrade radial artery puncture without sheath insertion in balloon-assisted radiocephalic AVF maturation. METHODS: We retrospective studied a total of 62 patients with immature radiocephalic AVF, who received balloon-assisted maturation in our hospital. 15 patients received pull-through technique through radial artery without sheath insertion and 47 patients received treatment through a regular venous approach. RESULTS: The success rate of pull-through technique group and control group was 86.7% (13 out of 15), 89.1% (41 out of 46) respectively. There was no significant difference between two groups (P > 0.05). In our study, there were 2 patients in the pull-through technique group and 3 patients in the control group, which had hematoma in the vein puncture site (P = 0.59). There were also no differences in the primary patency rate between two groups at 6 months and 12 months (76.9% vs 70.7%, 38.4% vs 41.5%, respectively, P > 0.05). CONCLUSION: The pull-through technique through antegrade radial artery without sheath insertion in promoting radiocephalic AVF maturation is effective and safe.

Autologous Alternative Vein Grafts for Infrainguinal Bypass in the Absence of Single-Segment Great Saphenous Vein: A Single-Center Study.

BACKGROUND: Alternative autologous veins can be used as a conduit when adequate great saphenous vein is unavailable. We analyzed the results of our infrainguinal bypasses after adopting upper extremity veins in our practice. METHODS: This is a single-center observational study involving all patients whose infrainguinal bypass involved the use of upper extremity veins between April 2019, when we began using arm veins, and February 2023. RESULTS: During the study period, 49 bypasses were done in 48 patients; mean age 68.1 ± 9.8; men 32 (66.7%); body mass index 28.0 ± 4.8; indications for surgery: chronic limb threatening ischemia 41 (83.7%); acute limb ischemia 3 (6.1%); complications of previous prosthetic 3 (6.1%), or autologous 2 (4.1%) bypass grafts. Vein splicing was used in 43 (87.8%) bypasses with 3-segment grafts being the most common (26; 53.1%). There were 24 (49.0%) femorotibial, 11 (22.4%) femoropopliteal, 9 (18.4%) femoropedal, and 5 (10.2%) extension jump bypass procedures. Eighteen (36.7%) operations were redo surgeries. Twenty-one (42.9%) bypasses were formed using only arm veins. The median follow-up was 12.9 months (4.5-24.2). Two bypasses occluded during the first 30 postoperative days (2/49; 4.1%). Overall 30-day, 1-year, and 2-year primary patency rates were 93.7% ± 3.5%, 84.8% ± 5.9%, and 80.6% ± 6.9%, and secondary patency (SP) rates were 95.8% ± 2.9%, 89.2% ± 5.3%, and 89.2% ± 5.3%. One-segment grafts had better patencies than 2-, 3-, and 4-segment grafts (1-year SP 100% ± 0% vs 87.6% ± 6.0%). Two-year amputation-free survival was 86.8% ± 6.5%; 2-year overall survival was 88.2% ± 6.6%. CONCLUSIONS: Integration of arm vein grafts in infrainguinal bypass practice can be done safely with low incidences of perioperative graft failure. One-segment grafts had better patencies than spliced vein grafts. The achieved early patency and amputation-free survival rates strongly encourage their use. In the absence of a single-segment great saphenous vein, upper extremity vein grafts should be the preferred conduit choice.

Comparison of Clinical Effectiveness and Safety of Drug-Coated Balloons versus Percutaneous Transluminal Angioplasty in Arteriovenous Fistulae: A Review of Systematic Reviews and Updated Meta-Analysis.

PURPOSE: To evaluate the clinical effectiveness and safety of drug-coated balloons (DCBs) compared with those of percutaneous transluminal angioplasty (PTA) for arteriovenous fistula (AVF) stenosis via a review of systematic reviews (SRs) and an update of the current meta-analysis. MATERIALS AND METHODS: Literature was searched to retrieve SRs comparing DCBs and PTA for AVFs. A narrative review of SRs and pooled analysis were performed. RESULTS: Eleven SRs were included. DCBs demonstrated favorable outcomes at 6 and 12 months compared with PTA, with improved patency in 7 SRs and a trend toward favorable outcomes without statistical significance in 3 SRs. Target lesion revascularization (TLR) was reported in 3 SRs; 2 reviews reported a significantly lower incidence in the DCB group than in the PTA group, whereas 1 review reported no significant differences at 12 months. Four studies reporting all-cause mortality revealed no significant difference between the 2 treatments. In the updated meta-analysis including 23 studies, DCBs demonstrated improved primary patency at 6 months (risk ratio [RR], 1.27; 95% CI, 1.07-1.50) and 12 months (RR, 1.36; 95% CI, 1.19-1.55) and were associated with a lower incidence of TLR at 6 months (RR, 0.54; 95% CI, 0.41-0.73) and 12 months (RR, 0.78; 95% CI, 0.62-0.99). There was no difference in mortality between the 2 groups for 24 months. CONCLUSIONS: A review of SRs and meta-analysis update revealed the consistent benefits of DCBs over PTA in treating AVFs in terms of primary patency and TLR. Compared with PTA, DCBs do not increase mortality risk.