Patency Rates Research Articles

A decade's experience with retrograde open mesenteric stenting for acute mesenteric ischemia

ObjectiveRetrograde open mesenteric stenting (ROMS) is an alternative to mesenteric bypass in patients with acute mesenteric ischemia (AMI) with variable reported 30-day mortality rates. Large studies evaluating patient outcomes following ROMS are scarce. Our study aims to assess the results of this approach among patients presenting with AMI. MethodsWe reviewed all the patients with AMI who were treated with ROMS (2011-2022). Patient demographics, presentation, operative details, and outcomes were analyzed. Primary end points were in-hospital, 30-day, and 1-year mortality. Kaplan-Meier estimate for 1-year mortality and primary patency loss were generated. Secondary end points included postoperative 30-day complications. ResultsBetween 2011 and 2022, ROMS was attempted on a total of 42 patients. The median age was 70 ± 15 years and the majority of patients were female. Pain out of proportion to the physical examination was the most common presenting symptom (n = 18, 42.9%) followed by peritonitis (n = 14, 33.4%). All patients underwent preoperative intravenous contrast computed tomography imaging. In situ thrombosis was identified as the etiology of AMI in 36 patients (85.7%). Technical success was achieved in 40 patients (95.2%). Conventional, non-hybrid operating rooms were used for the majority of cases. Revascularization of all 40 patients involved angioplasty and stenting of superior mesenteric artery. A single stent was placed in 35 patients (87.5%) and the reminder had more than one stent. Eighty percent of patients required bowel resection. A second-look laparotomy was required in 34 patients (85.0%). The mean operative time, including both the general surgery and vascular surgery portions of the index procedure, was 192 ± 57 minutes. Sepsis was the most common complication observed within 30 days, occurring in 8 patients (20.0%). In terms of mortality, 13 patients (32.5%) died during their index hospitalization, and 9 died (22.5%) within 30 days. On Kaplan-Meier analysis, the 1-year overall patient survival rate was 58.6%, and the primary patency rate for stents was 51.4%. ConclusionsROMS has an excellent technical success rate in management of AMI with lower than traditionally reported mortality rates for AMI. The dual benefits of rapid revascularization and bowel evaluation should make this surgical modality an alternative approach for treatment of AMI.

Infrapopliteal Bypass In Patients On Dialysis: Patency And Survival.

Portugal has one of the highest prevalence of patients on a regular dialysis program. This population has a higher incidence of peripheral arterial disease with higher rates of postoperative morbidity and mortality. Our goal was to compare outcomes between dialysis and non-dialysis patients with chronic limb threatening ischemia (CLTI) submitted to infrapopliteal bypass. A retrospective single-center study of infrapopliteal bypass for CLTI was performed between 2012 and 2019. Patients were divided in two groups based on dialysis status (group 1 incorporated patients on dialysis). Primary end point was 1-year freedom from CLTI. Secondary end points were limb-salvage, survival and primary (PP) and tertiary patency (TP) rates at 3 years of follow-up. A total of 352 infrapopliteal bypasses were performed in 310 patients with CLTI. Fourteen percent of the revascularizations were performed on dialysis patients (48/352). Median age was 73 years (interquartile range - IQR 15) and 74% (259/352) were male. Median follow-up was 26 months (IQR 42). Overall, 92% (325/352) had tissue loss and 44% (154/352) had some degree of infection. The majority of revascularization procedures were performed with vein grafts (61%, 214/352). The 30-day mortality was 4% (11/310), with no difference between groups (p = 0.627). Kaplan-Meier analysis showed no difference between groups regarding freedom from CLTI (76% vs. 79%; HR 0.96, CI 0.65-1.44, p=0.857), limb-salvage (70% vs. 82%; HR 1.40, CI 0.71-2.78, p=0.327) and survival (62% vs. 64%; HR 1.08, CI 0.60-1.94, p=0.799). PP rates were 39% in group 1 and 64% in group 2 (HR 1.71, CI 1.05-2.79, p=0.030). TP rates were not different between groups (57% and 78%; HR 1.79, CI 0.92-3.47, p=0.082). Infrapopliteal bypass for CLTI, on dialysis patients, resulted in lower PP rates. No differences were observed in freedom from CLTI, TP, limb salvage and survival.

Contemporary Therapy of Femoropopliteal In-Stent Restenosis / Occlusion, 36-month Follow up Study.

Drug-eluting devices improved outcomes of endovascular therapy (EVT) for femoropopliteal lesions, but mainly for de novo lesions. Endovascular therapy for in-stent restenosis/occlusion (ISR/O) is challenging, and large trials and long-term data are not well reported. This study is a physician initiated, multicenter, and retrospective design. From 7 Japanese institutes, 3635 femoropopliteal cases were enrolled in the study. Among these, 346 cases of first ISR/O were studied. We defined drug-coated-balloon, drug-eluting stent, and covered stent as New devices. Balloon angioplasty and bare nitinol stent were included in the control group. The propensity score matching extracted 112 pairs. At 12months, the primary patency rate was 80.3% in the new device group and 52.7% in the control group, and there was a significant intergroup difference (P = .004). However, at 36months, the rate was 43.3% vs 39.2%, with no significant difference (P = .090). No baseline characteristics had any significant interaction effect (all P > .05). The New devices were more effective than the control group for ISR/O at 1year, but caught up at 3years.

Role of Retrograde Tibiopedal Access in Limb Salvage in Patients with Critical Lower Limb Ischemia

AbstractThe aim of this study was to assess the efficacy and safety of retrograde tibiopedal access as an alternative approach in cases of critical limb ischemia (CLI) when antegrade access has failed. A prospective study was conducted that included patients with CLI who underwent tibiopedal access after failed antegrade recanalization from January 2018 to June 2022. Follow-up was conducted at 6, 12, and 24 months. The primary outcomes evaluated were technical success rate and primary patency. Secondary outcomes included complication rate, mortality rate, and limb salvage rate (LSR). Forty-eight patients had CLI and Trans Atlantic Inter-Society Consensus infrainguinal lesions. The retrograde approach was used through the anterior tibial artery in 28 patients (58%), the posterior tibial artery in 18 patients (37.5%), and the peroneal artery in 2 patients (4.5%). Technical success was achieved in 90% of patients (43 patients). There was a significant increase in the anklebrachial index after the procedure with a mean follow-up of 22 months. Twenty-two months primary patency rate was 85.2%, while secondary patency rate was 100% and LSR was 96%, respectively. There was no mortality in the series. Retrograde tibiopedal approach is an alternative option for managing peripheral arterial disease and CLI. This method offers another means of crossing lesions when antegrade access failed, and the intervention can be completed either in an antegrade or retrograde approach. As the retrograde approach does not impact access site, considered a feasible safe treatment alternative which increase the success rate of endovascular treatment.

Bypass Patency and Amputation-Free Survival after Popliteal Aneurysm Exclusion Significantly Depends on Patient Age and Medical Complications: A Detailed Dual-Center Analysis of 395 Consecutive Elective and Emergency Procedures.

Background/Objectives: A popliteal artery aneurysm (PAA) is traditionally treated by an open PAA repair (OPAR) with a popliteo-popliteal venous graft interposition. Although excellent outcomes have been reported in elective cases, the results are much worse in cases of emergency presentation or with the necessity of adjunct procedures. This study aimed to identify the risk factors that might decrease amputation-free survival (efficacy endpoint) and lower graft patency (technical endpoint). Patients and Methods: A dual-center retrospective analysis was performed from 2000 to 2021 covering all consecutive PAA repairs stratified for elective vs. emergency repair, considering the patient (i.e., age and comorbidities), PAA (i.e., diameter and tibial runoff vessels), and procedural characteristics (i.e., procedure time, material, and bypass configuration). Descriptive, univariate, and multivariate statistics were used. Results: In 316 patients (69.8 ± 10.5 years), 395 PAAs (mean diameter 31.9 ± 12.9 mm) were operated, 67 as an emergency procedure (6× rupture; 93.8% severe acute limb ischemia). The majority had OPAR (366 procedures). Emergency patients had worse pre- and postoperative tibial runoff, longer procedure times, and more complex reconstructions harboring a variety of adjunct procedures as well as more medical and surgical complications (all p < 0.001). Overall, the in-hospital major amputation rate and mortality rate were 3.6% and 0.8%, respectively. The median follow-up was 49 months. Five-year primary and secondary patency rates were 80% and 94.7%. Patency for venous grafts outperformed alloplastic and composite reconstructions (p < 0.001), but prolonged the average procedure time by 51.4 (24.3-78.6) min (p < 0.001). Amputation-free survival was significantly better after elective procedures (p < 0.001), but only during the early (in-hospital) phase. An increase in patient age and any medical complications were significant negative predictors, regardless of the aneurysm size. Conclusions: A popliteo-popliteal vein interposition remains the gold standard for treatment despite a probably longer procedure time for both elective and emergency PAA repairs. To determine the most effective treatment strategies for older and probably frailer patients, factors such as the aneurysm size and the patient's overall condition should be considered.

Recanalization of superficial femoral artery chronic total occlusion through retrograde popliteal approach recanalization of superficial femoral artery chronic total occlusion

PurposeThis retrospective study aims to evaluate the safety, practicality, and efficacy of the independent retrograde popliteal approach for recanalization superficial femoral artery (SFA) occlusions when the bilateral common femoral artery approach is unavailable, such as after endovascular aneurysm repair or common iliac artery stenting. MethodsThis treatment was considered for patients with contralateral iliac artery occlusion, severe iliac tortuosity, or those who had previously undergone endovascular aneurysm repair or common iliac stenting. Patients with SFA lesions extending into the P1–P2 segment of the popliteal artery or with calcification in the P3 segment were excluded. Angioplasty and stenting were conducted via the popliteal artery approach, with hemostasis at the puncture site achieved using an EXOSEAL vascular closure device. Patients were routinely followed up at 3, 6, and 12 months, and annually thereafter. ResultsForty-eight consecutive patients with SFA occlusion who underwent endovascular treatment via the retrograde popliteal artery approach were included in this study. Retrograde puncture of the popliteal artery was successful in all cases. Six-French sheaths were utilized in all procedures. The EXOSEAL vascular closure device was successfully applied in all 48 cases. No instances of pseudoaneurysms, arteriovenous fistulas, major bleeding, or embolic complications were observed. The technical success rate for SFA recanalization was 100 %. All patients experienced clinical improvement. The ankle-brachial index significantly increased from an initial 0.33 ± 0.11 at admission to 0.81 ± 0.19 at discharge (P < 0.001). The mean follow-up period was 25.1 ± 11.7 months. Kaplan-Meier analysis revealed primary patency rates of 82.5 % at 12 months and 71.8 % at 24 months. No patients required major amputation during the follow-up period. ConclusionThe endovascular treatment of SFA occlusions via the independent retrograde popliteal approach is a viable alternative, demonstrating a low incidence of puncture-related complications and a high success rate of recanalization.

Alternative vein bypass in octogenarians with chronic limb-threatening ischaemia.

Octogenarians are regarded as one of the frailest patient groups among the chronic limb-threatening ischaemia population with high perioperative morbidity and mortality rates. As a result, alternative vein bypass surgery in the absence of sufficient great saphenous vein is often not considered as a potential treatment option. The aim of this study was to compare the results of octogenarians undergoing alternative vein bypass surgery due to chronic limb-threatening ischaemia to younger patients. A single-centre retrospective analysis of patients undergoing bypass surgery for chronic limb-threatening ischaemia with alternative autologous vein grafts between 1997 and 2018 was performed. Patients aged over 80 years were compared with those under 80 years. Graft patency rates were assessed and a risk factor analysis for limb loss was performed. In total, 592 patients underwent bypass surgery during the study interval. Twenty-one per cent (n = 126) of patients were 80 years or older. At 4 years, primary, primary-assisted and secondary patency as well as limb salvage rates were not significantly different between the two groups (46% versus 50%, 60% versus 66%, 69% versus 72%, 72% versus 77%, for octogenarians versus non-octogenarians respectively). Major amputations were performed in 27 (21%) octogenarians and 91 (20%) non-octogenarians (P = 0.190). No higher 30-day and long-term mortality rates nor morbidity rates were detected in the octogenarian group with a median follow-up time of 27 (interquartile range 12-56) months. Minor amputation, the reason for alternative vein grafts, as well as the profunda femoris artery as proximal origin of the bypass were risk factors for limb loss in the postoperative course. Alternative vein bypass surgery in octogenarians with chronic limb-threatening ischaemia is safe and effective in terms of patency rates, limb salvage and survival compared with younger patients in the absence of sufficient great saphenous vein. Age alone should not be a deterrent from performing bypass surgery.

The efficacy of atherectomy combined with percutaneous transluminal angioplasty (PTA)/drug-coated balloon (DCB) compared with PTA/DCB for infrapopliteal arterial diseases: A systematic review and meta-analysis.

With the development of endovascular therapies, some studies have indicated a therapeutic potential for infrapopliteal arterial revascularization with atherectomy (AT). This study was designed to perform a meta-analysis to investigate the efficacy of AT combined with percutaneous transluminal angioplasty (PTA) or drug-coated balloon (DCB) compared with PTA or DCB for infrapopliteal arterial diseases. This is a systematic review and meta-analysis. The Pubmed, Web of Science, and Cochrane Library were systematically searched for articles published up to November 2022, reporting using atherectomy devices for infrapopliteal arterial patients. Randomized controlled trials and retrospective studies were included, and clinical characteristic outcomes were extracted and pooled. Then, we analyzed the efficacies of the AT (AT + PTA or DCB) group and the non-AT (DCB or PTA) group for infrapopliteal arterial patients. We identified 6 studies with 1269 patients included in this meta-analysis. The risk ratios (RRs) of primary patency for patients treated with atherectomy group compared to non-atherectomy group at 6months was 1.03 (95% confidence intervals (CIs) 0.86-1.23, p = .74), at 12months was 1.05 (95% CIs 0.84-1.30, p = .66), in the subgroup analysis between AT combined with DCB and DCB alone, the RRs of primary patency was 1.56 (95% CIs 1.02-2.39, p = .04). The RRs of freedom from target lesion revascularization (TLR) at 6 months was 1.04 (95% CIs 0.93-1.17, p = .45), at 12 months was 1.20 (95% CIs 0.83-1.75, p = .33). The RRs of mortality at 6 months was 0.57 (95% CIs 0.29-1.11, p = .10), and at 12 months was 0.79 (95% CI 0.50-1.25, p = .31). The RRs of limb salvage at 12 months was 0.99 (95% CIs 0.92-1.07, p = .87). The standardized mean difference (SMD) of (Ankle-brachial index) ABI at 12months was 0.16 (95% CIs 0.06-0.26, p = .001). According to this systematic review and meta-analysis, no significant advantages were found with the addition of atherectomy to balloon angioplasty in the below-the-knee segment. Only in the analysis of a small subgroup of atherectomy + DCB versus DCB alone was the primary patency rate at six months significantly higher when adding atherectomy. No further significant differences were found related to 12months of primary patency, TLR, limb salvage, and mortality among groups.

Endovascular Transvenous versus Open Femoropopliteal Bypass.

Background and Objectives: Lower extremity arterial disease is one of the most prevalent manifestations of atherosclerosis. The results from numerous studies regarding the best revascularization method of an occluded superficial femoral artery have been conflicting. The aim of this study was to compare the patency of transvenous endovascular with open femoropopliteal bypass, both with vein and prosthetic grafts. To our knowledge, a direct patency comparison between transvenous endovascular and open femoropopliteal bypass has not been published. This could help elucidate which method is preferable and in which cases. Materials and Methods: Patients with complex TASC-C and D SFA lesions were offered endovascular transvenous or open bypass. A total of 384 consecutive patients with PAD requiring surgical treatment were evaluated for inclusion in this study. Three-year follow-up data were collected for 52 endovascular procedures, 80 prosthetic grafts, and 44 venous bypass surgeries. Bypass patency was investigated by Duplex US every 6 months. Kaplan-Meier plots were used to analyze primary, primary-assisted, and secondary patency for endovascular transvenous, autovenous, and prosthetic bypasses. Results: Primary, primary-assisted, and secondary patency in venous group at 3 years was 70.5%, 77.3%, and 77.3%, respectively. In the endovascular transvenous group, primary, primary-assisted, and secondary patency at 3 years was 46.2%, 69.2%, and 76.9%, respectively. The lowest patency rates at 3 years were noted in the prosthetic graft group with 22.5% primary, 26.6% primary-assisted, and 28.2% secondary patency. Conclusions: The saphenous vein is the best graft to perform in above-the-knee femoropopliteal bypass. Transvenous endovascular bypass is a viable option with comparable primary-assisted and secondary patency. Primary patency is substantially lower for endovascular transvenous compared to venous bypass. Patients treated with endovascular transvenous bypass will require a significant number of secondary procedures to provide optimal patency. Prosthetic grafts should only be used if no other option for bypass is available.

Femoral vein translocation for complex hemodialysis access

ObjectiveVascular access is difficult in patients without suitable arm veins and prior graft infections. The use of femoral vein translocation (FVT) to the upper extremity or contralateral lower extremity for hemodialysis access may be associated with low infection rates and high patency rates. FVT is used for patients without central venous occlusion who have failed prior access either owing to graft infection or repetitive graft thrombosis. The largest case series consists of 30 cases. The objective of this study is to determine the infection incidence, primary patency, primary-assisted patency, and secondary patency rates among FVTs. MethodsA retrospective chart review was performed on all patients who underwent FVT by a single vascular practice over a 10-year period (2013-2023). Study variables included length to last follow-up (months), prior access, prior graft infection, comorbid conditions, primary patency, primary-assisted patency, secondary patency, postoperative steal syndrome, postoperative graft infection, postoperative harvest site complication, and postoperative lower extremity compartment syndrome. ResultsA total of 131 FVTs were performed from 2013 to 2023; 126 patients (47% male, 53% female; 76% Black, 24% White) with a mean age of 52 ± 14 years and a mean body mass index of 29 ± 8 had at least 1 month of follow-up and were included for analysis. The median follow-up was 46 months (interqurtile range, 19-72 months). The mean number of prior permanent accesses was 2.5 ± 1.4. Forty-eight percent of patients had prior graft infections. The primary, primary-assisted, and secondary patency rates were 66%, 93%, and 98%, respectively, at 6 months; 43%, 85%, and 96% at 12 months; 25%, 70%, and 92% at 24 months; 16%, 61%, and 88% at 36 months; and 14%, 56%, and 82% at 48 months. Postoperative steal syndrome and postoperative access infection requiring excision was observed 16% and 5% of patients, respectively. Harvest site complications requiring an additional procedure occurred in 19% of cases. Three patients developed lower extremity compartment syndrome postoperatively, requiring fasciotomy. Six patients developed chronic lower extremity edema after femoral vein harvest. The mean procedure time and hospital length of stay were 197 ± 40 minutes and 3.5 ± 2.8 days, respectively. ConclusionsFVT is associated with low infection rates and high long-term patency rates. Significant postoperative complications include steal syndrome and harvest site complications. FVT remains a viable option for patients who have failed prior access owing to graft infection or repetitive graft thrombosis.

Comparison of total percutaneous in situ microneedle puncture and chimney technique for left subclavian artery fenestration in thoracic endovascular aortic repair for type B aortic dissection.

To compare the outcomes of totally percutaneous in situ microneedle puncture for left subclavian artery (LSA) fenestration (ISMF) and chimney technique in type B aortic dissection (TBAD) during thoracic endovascular aortic repair (TEVAR). Data on patients who underwent either chimney-TEVAR (n = 89) or ISMF-TEVAR (n = 113) from October 2018 to April 2022 were analyzed retrospectively. The primary outcomes were mortality and major complications at 30 days and during follow-up. The technical success rate was 84.3% in the chimney group and 93.8% in the ISMF group (p = 0.027). The incidence of immediate endoleakage was significantly higher in the chimney than ISMF group (15.7% vs 6.2%, respectively; p = 0.027). The 1- and 3-year survival rates in the chimney and ISMF groups were 98.9% ± 1.1% vs 98.1% ± 0.9% and 86.5% ± 6.3% vs 92.6% ± 4.1%, respectively (log-rank p = 0.715). The 3-year rate of cumulative freedom from branch occlusion in the chimney and ISMF group was 95.4% ± 2.3% vs 100%, respectively (log-rank p = 0.023). Both ISMF-TEVAR and chimney-TEVAR achieved satisfactory short- and mid-term outcomes for the preservation of the LSA in patients with TBAD. ISMF-TEVAR appears to offer better clinical outcomes with higher patency and lower reintervention rates. However, ISMF-TEVAR had longer operation times with higher procedure expenses. When LSA revascularization is required during TEVAR, in situ, fenestration, and chimney techniques are all safe and effective methods; in situ, fenestration-TEVAR appears to offer better clinical outcomes, but takes longer and is more complicated. LSA revascularization during TEVAR reduces post-operative complication rates. Both in situ ISMF-TEVAR and chimney-TEVAR are safe and effective techniques for the preservation of the LSA during TEVAR. The chimney technique is associated with a higher incidence of endoleakage and branch occlusion, but ISMF-TEVAR is a more complicated and expensive technique.

Outcomes of Surgical and Endovascular Treatment for Cephalic Arch Stenosis in Proximal Arteriovenous Fistula.

The cephalic arch is a significant site of stenosis in proximal arteriovenous fistulas (AVFs) that contributes to access dysfunction and thrombosis. This study aimed to evaluate the outcomes of surgical treatment (ST) and endovascular treatment (ET) for cephalic arch stenosis (CAS). A total of 62 patients with proximal AVF who underwent CAS revision using either ST or ET were enrolled between January 2018 and March 2023. In the ET group, only the initial ET following AVF formation was considered, to mitigate bias. In the ST group, central transposition of the native AVF (transposition group) or interposition of the prosthetic graft into the proximal basilic or axillary vein (interposition group) was performed. We evaluated primary and functional patency based on these groups and calculated the number of patency loss events after CAS treatment. Of the 62 patients, 38 (61%) were male, with a mean age of 66.4 years. ST was performed in 26 (42%) patients, including transposition in 16 and interposition in 10, whereas ET was administered to 36 patients during the study period. Among the ST recipients, 42% had a history of ET for CAS. The incidence of AVF thrombosis was marginally higher in the ST group than in the ET group (39% vs. 19%, P=0.098). The primary patency rates at 6 months, 1 year, and 3 years were 87%, 87%, and 66% in the transposition group; 45%, 23%, and 11% in the interposition group; and 66%, 49%, and 17% in the ET group, respectively. Notably, the primary patency of the transposition group was significantly higher than that of the interposition (P=0.001) and ET groups (P=0.016). The frequency of patency loss events per person-year after the initial revision was 0.40, 0.52, and 1.42 in the transposition, interposition, and ET groups, respectively. Transposition exhibited the most favorable primary patency rate and the lowest number of subsequent patency loss events during follow-up despite the higher rates of AVF thrombosis and previous ET at presentation. Consequently, transposition should be actively considered in eligible patients with CAS.

Editor's Choice – Outcomes of Cold Stored Saphenous Vein Allografts for Haemodialysis Vascular Access

The aim of this study was to evaluate the outcomes of cold stored saphenous vein allografts (CSVAs) for haemodialysis vascular access. A retrospective, two centre study was conducted between January 2016 and December 2020 of all patients who had CSVA placement for haemodialysis vascular access. Primary, primary assisted, and secondary patency were analysed, as well as procedural complications and re-interventions. One hundred and nine patients (n= 55 women) with a mean age of 67.2 ± 13.6 years, with no options for creating an autogenous arteriovenous fistula, were included in the study. At one year, primary, primary assisted, and secondary patency were 37.6%, 59.0%, and 73.3%, respectively; and at two years 19.9%, 42.5%, and 54.9%, respectively. During a mean follow up period of 26 ± 18 months, five patients (4.6%) had an access infection, with no related death. During the follow up period, 32 patients (29.4%) died and 13 patients (11.9%) underwent a kidney transplant. None of these patients showed immunoconversion before transplantation. The cumulative incidence of adverse events by the Fine-Gray method was calculated. Considering competing risks (death and renal transplantation), 9.2% of patients lost their vascular access at one year and 18% at two years. Moreover, 57.8% patients had stenosis, mainly on the outflow (45.9%), and 49.5% had thrombosis. With a comparable patency rate associated with a low infection rate, CSVA offers a potential alternative to expanded polytetrafluoroethylene grafts. This creates haemodialysis vascular access when the venous capital is exhausted in patients with reported risk factors for vascular access infection, i.e., insertion in the thigh, advanced age, diabetes mellitus, immunocompromised state, obesity, or revision of an infected prosthetic graft.

Snuffbox distal transradial access (dTRA) for arteriovenous fistuloplasty in Singapore: Going distal is safe.

Arteriovenous fistula (AVF) dysfunction resulting from stenosis or occlusion, is a prevalent issue in end-stage renal failure patients reliant on autogenous AVFs for dialysis. Recently, a distal transradial approach (dTRA) has emerged, offering advantages such as diminished access site complications, better patient comfort and reduced risk of radial artery occlusion. Our study seeks to assess the effectiveness, outcomes and complication rates of employing dTRA for arteriovenous fistuloplasty in Singaporean patients. A retrospective review of all dTRA fistuloplasties performed on dysfunctional or slow to mature AVFs from 2017 to 2023 in our institution was performed. Patients with a distal radial artery measuring 2 mm or more with no evidence of occlusion or thrombosis were included. Patients who required central venoplasty or cutting balloon angioplasty were excluded. Outcome measures included technical success, mean procedure duration, complications and post-intervention primary patency at 1, 3 and 6 months. Patients were followed up for 12 months post-intervention. A total of 37 patients were included. 97.3% of patients undergoing dTRA fistuloplasty had radiocephalic fistulas while 2.7% had brachiobasilic fistulas. There was 100% technical success (defined as success in radial artery cannulation, sheath insertion and crossing of stenotic lesions) in our study as all patients successfully underwent fistuloplasty via dTRA approach. One-month patency rate was 97.4%, 3-month patency rate was 92.1% and 6-month patency rate was 86.8%. There were no immediate complications (haematoma, infection, bleeding, pseudoaneurysm, occlusion) of the radial artery post-intervention. Our paper illustrates the safety and efficacy of utilising dTRA for arteriovenous fistuloplasty. This approach offers distinct benefits in addressing non-mature or dysfunctional distal forearm arteriovenous fistulas and should be taken into account in anatomically suitable cases.

The influence of near-infrared therapy on arteriovenous fistula patency in haemodialysis patients: A multicentre, randomised, controlled clinical trial.

Arteriovenous fistula (AVF) is the preferred vascular access for patients undergoing haemodialysis (HD). AVF malfunction remains a major clinical problem and is a significant independent risk factor for death. Although far-infrared (FIR) therapy has been shown to reduce complications and improve the patency rate of AVFs in various studies, it has been cautiously recommended by the Kidney Disease Outcome Quality Initiative (KDOQI) guidelines for AVF care due to insufficient evidence. Therefore, it is necessary to identify more effective methods for preventing AVF dysfunction. Many in vitro studies and few clinical studies have examined the effects of near-infrared (NIR) therapy on the vasculature. This study will examine the effects of NIR therapy on AVF. A randomised, controlled, open-label, multicentre trial will compare the effect of NIR on AVF patency after 1 year of therapy with that of a control group of patients with existing AVF. One group of patients received NIR treatment above their AVFs, whereas the control group received regular care. The primary outcome is the primary fistula patency rate within 12 months. In addition, acute changes in inflammatory, vasodilatory and haemodynamic parameters after a single treatment in the first 40 participants will be examined. This study was registered in the Clinical Trials Registry (ChiCTR2300071305) at https://register.clinicaltrials.gov/. This study will explore the long-term and acute effects of NIR on AVFs. The study findings will provide information that can be used to develop new technical support for the prevention of AVF dysfunction in patients undergoing haemodialysis.

Three-Dimensional Bio-Printed Tubular Tissue Using Dermal Fibroblast Cells as a New Tissue-Engineered Vascular Graft for Venous Replacement.

The current study was a preliminary evaluation of the feasibility and biologic features of three-dimensionally bio-printed tissue-engineered (3D bio-printed) vascular grafts comprising dermal fibroblast spheroids for venous replacement in rats and swine. The scaffold-free tubular tissue was made by the 3D bio-printer with normal human dermal fibroblasts. The tubular tissues were implanted into the infrarenal inferior vena cava of 4 male F344-rnu/rnu athymic nude rats and the short-term patency and histologic features were analyzed. A larger 3D bio-printed swine dermal fibroblast-derived prototype of tubular tissue was implanted into the right jugular vein of a swine and patency was evaluated at 4 weeks. The short-term patency rate was 100%. Immunohistochemistry analysis showed von Willebrand factor positivity on day 2, with more limited positivity observed on the luminal surface on day 5. Although the cross-sectional area of the wall differed significantly between preimplantation and days 2 and 5, suggesting swelling of the tubular tissue wall (both p < 0.01), the luminal diameter of the tubular tissues was not significantly altered during this period. The 3D bio-printed scaffold-free tubular tissues using human dermal or swine fibroblast spheroids may produce better tissue-engineered vascular grafts for venous replacement in rats or swine.

Influence of Preprocedural Statin Usage on Primary Patency and Amputation in Patients Undergoing Lower Limb Peripheral Angioplasty

Peripheral arterial disease can progress to critical limb ischemia, which is associated with high amputation rates and requires revascularization. The endovascular approach has lower long-term patency because of restenosis due to neointimal hyperplasia. Statins are significantly advantageous for patients undergoing percutaneous interventions; however, only few studies have reported surgical improvements with statin therapy after endovascular treatment in such patients. This retrospective cohort study assessed the effects of preprocedural statins on lower limb arterial angioplasty outcomes by evaluating patency and amputation rates and comparing with those without statins. Patients who underwent percutaneous transluminal angioplasty of the lower limbs for critical ischemia of the lower limbs or for limiting claudication were included in this retrospective cohort study. Patients were categorized according to statin use prior to and during hospitalization. Patient demographics, lesion morphology, primary patency, and limb salvage rates were compared between these groups. Statistical analyses were performed using Kaplan-Meier and multivariate regression analysis. A total of 178 patients undergoing endovascular intervention by critical ischemia or limiting claudication were included. Approximately 80% of the procedures were ballon angioplasty. Primary patency was 73% in 1year and preprocedural statin usage was not associated with improved primary patency rates (P=0.2798). After adjusting the amputation outcomes for pre-established variables, such as prehospitalization statin use, diabetes, procedure indication, disease location, Trans-Atlantic Inter-Society Consensus classification, and current smoking, there was no statistically significant difference associated with preprocedural statin use in primary patency (hazard ratio: 0.87 [0.33-2.29], P=0.79) or amputation (hazard ratio: 0.70 [0.40-1.23], P=0.22). The use of preprocedural statin did not improve primary patency or amputation rates in patients undergoing peripheral angioplasty.

Long-term clinical outcomes of arterial bypass and the factors independently associated with the primary patency in patients with suprainguinal arterial occlusion

IntroductionAortoiliac occlusive disease and iliofemoral occlusion are impact patient quality of life, cause limb loss and mortality. The aim of this study was to investigate the long-term clinical outcomes of arterial bypass, and the factors associated with the outcomes. MethodThis retrospective chart/image review included all types of arterial bypass procedures performed for suprainguinal arterial occlusion during January 2004 to December 2017. The primary outcome was the primary patency. The secondary outcomes were the secondary patency, amputation-free survival, overall survival and the factors associated with the outcomes. ResultA total of 135 patients (107 males) were included. The median age was 65 years. The 1-year, 5-year, and 10-year primary patency rates were 74.3%, 65.7%, and 55.6%, respectively, with independent predictors of poor outcomes being underlying cerebrovascular disease (p = 0.003) and postoperative graft infection (p = 0.016). Secondary patency rates at 1-year, 5-year, and 10-year intervals were 90.1%, 87.1%, and 77.8%, respectively, with independent predictors of poor outcomes being underlying cardiovascular disease (p = 0.013) and postoperative acute kidney injury (p = 0.010). Amputation-free survival rates at 1-year, 5-year, and 10-year intervals were 77.1%, 71.6%, and 66.0%, respectively, with the independent predictor of poor outcome being preoperative foot infection (p = 0.013). Overall survival rates at 1-year, 5-year, and 10-year intervals were 84.4%, 58.6%, and 35.3%, respectively, with independent predictors of poor outcomes being chronic kidney disease (p = 0.030) and postoperative myocardial infarction (p = 0.018). However, antiplatelet therapy emerged as an independent predictor of favorable overall survival outcomes (p = 0.034). ConclusionOur results showed the primary patency rates of arterial bypass to be relatively low at our center; however, most grafts could be saved with high secondary patency. Both disease-associated factors and patient condition-associated factors were found to influence the outcomes of this fragile patient population.

Abstract 1130: Tenascin-C In Arteriovenous Fistula Failure: Unraveling Venous Remodeling Dynamics

Background: AVF are the preferred vascular access for hemodialysis, with superior patency and lower infection rates than grafts or catheters. Nevertheless, AVF patency is reduced by both early thrombosis and NIH, culminating in diminished utilization due to one-year patency rates as low as 40-50%. Tenascin-C (TnC), an ECM glycoprotein with limited adult expression, is transiently present at sites of tissue injury and inflammation. TnC has been implicated in playing a role in the development of NIH. Hypothesis: Sustained TnC expression contributes to NIH, potentially leading to AVF failure. Methods: Female and male wild-type C57Bl/6 mice, aged 9-11 weeks, had sham surgery or AVF creation by puncturing the infrarenal aorta into the inferior vena cava (IVC) with a 25-gauge needle. Doppler ultrasound confirmed AVF presence. Tissue samples were collected for IF, WB, and qPCR. Human matched vein and AVF tissue were obtained from patients undergoing planned two-stage AVF creation surgeries and analyzed with IF. In vitro analysis of human dermal microvascular endothelial cells (HDMEC) was performed to investigate the role of TnC in thrombomodulin expression. Results: TnC expression significantly increased in the AVF by day 7, returning to baseline by day 21 and reaching negligible levels by day 42. The spatial and temporal regulation of TnC expression post-AVF creation correlated with ECM remodeling and inversely with thrombomodulin. Both mice and human studies demonstrated differential regulation of TnC and thrombomodulin in patent and occluded AVF. In HDMEC, TnC knockdown suppressed NF-kB expression and increased thrombomodulin expression, while exogenous TnC had the opposite effect. Conclusion: TnC plays a pivotal role in driving pathological inflammation, with its expression being both temporally and spatially regulated during venous remodeling post-AVF creation. Persistent TnC expression is noted in occluded mouse and human AVF, leading to decreased thrombomodulin expression and heightened thrombogenicity. Sustained TnC expression regulates the shift from physiological to pathological venous remodeling, underscoring the crucial role of the immune response in this process and highlighting potential translational therapeutic strategies.

Intravascular Ultrasound Use is Associated with Improved Patency in Lower Extremity Peripheral Arterial Interventions

ObjectivesIntravascular ultrasound (IVUS) facilitates detailed visualization of endoluminal anatomy not adequately appreciated on conventional angiography. However, it is unclear if IVUS use improves clinical outcomes of peripheral vascular interventions (PVI) for peripheral arterial disease (PAD). This study aimed to evaluate the impact of IVUS on 1-year outcomes of PVI in the vascular quality initiative (VQI). MethodsThe VQI-PVI modules were reviewed (2016-2020). All patients with available one-year follow up after lower extremity PVI were included and grouped as IVUS-PVI or non-IVUS PVI based on use of IVUS. Propensity matching (1:1) was performed using demographics and comorbidities. One-year major amputation and patency rates were compared. A generalized estimating equation (GEE) model was used to identify predictors of 1-year outcomes. Subgroup analysis based on Trans-Atlantic Inter-Society Consensus (TASC) classification, treatment length and treatment modalities were performed using same modeling approaches. ResultsThere were 56,633 procedures (non-IVUS PVI=55,302 vs IVUS-PVI=1,331) in 44,042 patients. Propensity matching yielded a total cohort of 1,854 patients matched (1:1), with no baseline differences. LER for claudication was performed in 60.4%, while one-third (33.9%) had chronic limb threatening ischemia (CLTI). IVUS was more commonly used for lesions >15cm in length (46.6% vs 43.3%) and for aortoiliac disease (31.8% vs 27.2%). Rates of atherectomy and stenting were significantly higher with IVUS-PVI (21.1% vs 16.8%), while balloon angioplasty was less common (13.5% vs 24.4%). One-year patency was better with IVUS-PVI (97.7% vs 95.2%, p=0.004). On subgroup analysis, IVUS (OR 2.20, 95% CI 1.29- 3.75) was associated with improved patency in CLTI patients, TASC C or D lesions, and treatment length >15cm. Adjunctive IVUS use during PVI did not significantly impact 1-year amputation (OR 1.7, 95%CI 0.78-3.91). On multivariable regression, adjunctive use of IVUS (OR 2.46 95%CI 1.43-4.25) and aortoiliac interventions (OR 2.91, 95%CI 1.09-7.75) were independent predictors of patency. Treatment modalities such as atherectomy, stenting or balloon angioplasty did not significantly impact patency at 1-year. ConclusionIVUS during lower extremity PVI is associated with improved 1-year patency, when compared to angiography alone. Certain subgroups, such as CLTI patients, lesions>15cm, and TASC C or D lesions might benefit from adjunctive use of IVUS.