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

AIM: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Risk Prediction of Diabetic Foot Amputation Using Machine Learning and Explainable Artificial Intelligence.

BACKGROUND: Diabetic foot ulcers (DFUs) are serious complications of diabetes which can lead to lower extremity amputations (LEAs). Risk prediction models can identify high-risk patients who can benefit from early intervention. Machine learning (ML) methods have shown promising utility in medical applications. Explainable modeling can help its integration and acceptance. This study aims to develop a risk prediction model using ML algorithms with explainability for LEA in DFU patients. METHODS: This study is a retrospective review of 2559 inpatient DFU episodes in a tertiary institution from 2012 to 2017. Fifty-one features including patient demographics, comorbidities, medication, wound characteristics, and laboratory results were reviewed. Outcome measures were the risk of major LEA, minor LEA and any LEA. Machine learning models were developed for each outcome, with model performance evaluated using receiver operating characteristic (ROC) curves, balanced-accuracy and F1-score. SHapley Additive exPlanations (SHAP) was applied to interpret the model for explainability. RESULTS: Model performance for prediction of major, minor, and any LEA event achieved ROC of 0.820, 0.637, and 0.756, respectively, with XGBoost, XGBoost, and Gradient Boosted Trees algorithms demonstrating best results for each model, respectively. Using SHAP, key features that contributed to the predictions were identified for explainability. Total white cell (TWC) count, comorbidity score and red blood cell count contributed highest weightage to major LEA event. Total white cell, eosinophils, and necrotic eschar in the wound contributed most to any LEA event. CONCLUSIONS: Machine learning algorithms performed well in predicting the risk of LEA in a patient with DFU. Explainability can help provide clinical insights and identify at-risk patients for early intervention.

Use of Wallstent device as an embolic protection device during stenting of aortic thrombus.

Blue toe syndrome can occur due to distal embolization from proximal lesions such as an aortic thrombus. We describe the case of a patient who presented with chronic limb threatening ischemia due to a flow-limiting infrarenal aortic thrombus, with gangrene from distal embolization to the left fifth toe, and was successfully treated with endovascular aortic stent graft insertion. Distal embolization during instrumentation was successfully prevented by using a partially deployed Wallstent (Boston Scientific) as an embolic protection device. The reconstrainable Wallstent device can be considered for distal thromboembolic protection during aortic stenting, in particular, when distal embolization is a concern and commercial devices are not readily available.

The Utility of Ultrasound Guidance to Improve the Safety of Closure of Antegrade Common Femoral Artery Access after Lower Limb Revascularization.

This study aimed to investigate the feasibility of ultrasound (US)-guidance in reducing adverse event (AE) rates when using Angioseal device during antegrade lower limb angioplasty via common femoral artery access. From December 2016 to November 2022, 1,322 patients were identified, including 1,131 (85.6%) patients who underwent US-guided closure and 191 (14.4%) who underwent non-US-guided closure. Moderate AEs were encountered in 10 (5.2%) patients in the non-US-guided closure group compared to 38 (3.4%) patients in the US-guided closure group (P = .208). Severe AEs were encountered in 4 (2.1%) patients in the non-US-guided closure group compared to 3 (0.3%) patients in the US-guided closure group (P = .010). Overall AEs occurred in 14 (7.3%) patients in the non-US-guided closure group compared to 41 (3.6%) patients in the US-guided closure group (P = .029). Binary logistic regression showed that only non-US guidance was an independent risk factor for the occurrence of severe AEs (P = .008).

Getting a Foothold on Diabetic Foot Disease-Outcomes of a Multidisciplinary Clinical Pathway for Inpatient Diabetic Foot Care: A 17-Year Institutional Review.

INTRODUCTION: Diabetes foot disease (DFD) contributes to poor quality of life, clinical and economic burden. Multidisciplinary diabetes foot teams provide prompt access to specialist teams thereby improving limb salvage. We present a 17-year review of an inpatient multidisciplinary clinical care path (MCCP) for DFD in Singapore. METHODS: This was a retrospective cohort study of patients admitted for DFD and enrolled in our MCCP to a 1700-bed university hospital from 2005 to 2021. RESULTS: There were 9279 patients admitted with DFD with a mean of 545 (±119) admissions per year. The mean age was 64 (±13.3) years, 61% were Chinese, 18% Malay and 17% Indian. There was a higher proportion of Malay (18%) and Indian (17%) patients compared to the country's ethnic composition. A third of the patients had end stage renal disease and prior contralateral minor amputation. There was a reduction in inpatient major lower extremity amputation (LEA) from 18.2% in 2005 to 5.4% in 2021 (odds ratio 0.26, 95% confidence interval 0.16-0.40, P < .001) which was the lowest since pathway inception. Mean time from admission to first surgical intervention was 2.8 days and mean time from decision for revascularization to procedure was 4.8 days. The major-to-minor amputation rate reduced from 1.09 in 2005 to 0.18 in 2021, reflecting diabetic limb salvage efforts. Mean and median length of stay (LOS) for patients in the pathway was 8.2 (±14.9) and 5 (IQR = 3) days, respectively. There was a gradual trend of increase in the mean LOS from 2005 to 2021. Inpatient mortality and readmission rate was stable at 1% and 11%. CONCLUSION: Since the institution of a MCCP, there was a significant improvement in major LEA rate. An inpatient multidisciplinary diabetic foot care path helped to improve care for patients with DFD.

Single-centre experience with endovascular rotational thrombectomy for single session salvage of thrombosed arteriovenous fistulas and grafts.

OBJECTIVES: This paper documents our experience and outcomes of using a relatively new endovascular rotational thrombectomy device for salvage of thrombosed vascular access. METHODOLOGY: A retrospective study reviewing patients with thrombosed native AVF or AVG who underwent endovascular declotting using a rotational thrombectomy device between November 2018 and May 2020 at a tertiary university hospital in Southeast Asia. We evaluated demographics, procedural data, technical and procedural success, patency rates and complications. RESULTS: A total of 40 patients underwent single session endovascular declotting of thrombosed vascular access. The mean follow-up period was 21.6 months (range 13.4-31 months). The technical success was 92.5% and clinical success was 80%. About 50% of patients had concomitant thrombolysis for pharmacomechanical thrombectomy. One patient had a myocardial infarction during the post-operative period. There were no other major complications within 30 days. The primary patency was 45.5% at 6 months and 22.7% at 12 months. Assisted primary patency was 68.1% at 6 months and 61.6% at 12 months, which was maintained up to 2 years. The secondary patency was 84.1% at 6 and 12 months. CONCLUSION: Our study shows that rotational thrombectomy device for single session thrombectomy of thrombosed arteriovenous fistulas and grafts is safe and effective. A high technical and clinical success rate was achieved, with low complication rates and specific advantages compared to other techniques, including reduced length of hospital stay. Our reported mid-term outcomes are reasonable with an assisted primary patency of 62% at 12 and 24 months. The use of newer techniques and novel dedicated thrombectomy devices show promise.

Endovascular repair of mycotic aortic aneurysms confers good medium-term outcomes and aneurysmal sac resolution.

INTRODUCTION: Mycotic aortic aneurysm (MAA) is a life-threatening condition. Endovascular repair (EVAR) of aortic aneurysms has been found to be a safe and effective alternative to open repair. We aimed to present the short- to medium-term outcomes for EVAR of MAA in our cohort. METHODS: We conducted a retrospective study of 23 consecutive patients with MAA who underwent EVAR in our hospital from January 2008 to July 2017. RESULTS: The mean age of our study population was 62 years. The mean aneurysmal size was 3.2 cm. Abdominal MAAs (n = 16, 70%) were the most common, followed by thoracic MAAs (n = 4, 17%). There was no 30-day mortality in our cohort. Endoleak (Types 1, 3, 4) was detected in 3 (13%) cases. At the one-month surveillance computed tomography aortogram, all patients had a reduction in aneurysmal size and 5 (22%) had complete aneurysmal sac resolution. 7 (30%) patients had sac resolution at six months and 8 (35%) patients, at 12 months. The overall survival was 91%, 80% and 61% at one, 12 and 60 months, respectively. CONCLUSION: EVAR is a feasible and durable method for the repair of MAA, with a five-year overall survival of 61%. All patients in our study had a reduction in aneurysmal size at one month, with 65% having complete aneurysmal sac resolution by 12 months.

Intravascular ultrasound correlation of unenhanced magnetic resonance venography in the context of pelvic deep venous disease.

OBJECTIVE: In the present retrospective, assessor-blinded cross-sectional study, we compared the diagnostic efficacy of the relaxation-enhanced angiography without contrast and triggering (REACT) protocol for magnetic resonance venography (MRV) and intravascular ultrasound (IVUS). METHODS: All patients without prior lower limb vascular stenting who had undergone MRV with the REACT protocol and IVUS at our institution from January 2018 to May 2020 were included. The REACT protocol for MRV comprises three main phases: the adiabatic-based T2-preparation module, the non-volume-selective short tau inversion recovery pulse sequence, and the three-dimensional, modified two-point chemical-shift water-fat separated turbo-field echo pulse sequence. The IVUS findings served as the reference standard for stenosis and were used in the diagnostic efficacy analysis of the REACT protocol for MRV. The REACT protocol MRV images were reviewed by three board-certified interventional radiologists, and an interrater analysis was performed. RESULTS: A total of 33 patients (110 segments with IVUS correlation; 18 men [54.5%] and 15 women [45.5%]) were included. Most patients were Chinese (63.6%), and 24 had had bilateral deep venous disease (72.7%). The mean patient age was 59.0 years (range, 26.0-79.5 years). Moderate agreement was found between the three radiologists' diagnoses of iliac vein pathology using the REACT protocol for MRV (κ = 0.524; 95% confidence interval [CI], 0.426-0.623; P < .001). Compared with IVUS, REACT protocol MRV achieved a sensitivity of 96.10% (95% CI, 89.03%-99.19%), specificity of 78.79% (95% CI, 61.09%-91.02%), positive predictive value of 91.36% (95% CI, 84.54%-95.33%), and negative predictive value of 89.66% (95% CI, 73.81%-96.38%). Overall, 78.5% agreement was noted between the REACT protocol MRV and IVUS findings. Good agreement between the index test and reference standard was noted (κ = 0.779; 95% CI, 0.645-0.907; P ≤ .05). CONCLUSIONS: REACT protocol MRV has the potential to be a highly sensitive and specific screening tool to diagnose deep venous disease.

Cost-Effectiveness of Drug-Coated Balloon Angioplasty Versus Conventional Balloon Angioplasty for Treating Below-the-Knee Arteries in Chronic Limb-Threatening Ischemia: The SINGA-PACLI Trial.

PURPOSE: Drug-coated balloon angioplasty (DCBA) has been studied as a potentially superior option compared to conventional percutaneous transluminal angioplasty (PTA) in treating below-the-knee (BTK) arteries in chronic limb-threatening ischemia (CLTI). The aim of this study is to examine the cost-effectiveness of DCBA versus PTA in BTK arteries based on a randomized controlled trial. MATERIAL AND METHODS: A prospective economic study was embedded in a randomized controlled trial of 138 patients with CLTI. Resource use and health outcomes were assessed at baseline, and at 3, 6 and 12 months post-intervention. Costs were calculated from a societal perspective and health outcomes measured using quality-adjusted life years with probabilistic sensitivity analysis performed to account for subject heterogeneity. RESULTS: Compared with participants randomized to receive PTA, participants randomized to DCBA gained an average baseline-adjusted quality-adjusted life years (QALYs) of .012 while average total costs were USD$1854 higher; this translates to an incremental cost-effectiveness ratio (ICER) of US$154,500 additional cost per QALY gained. However, the estimate of ICER had substantial variance with only 48% of bootstrap ICERs meeting a benchmark threshold of US$57,705 (the average gross domestic product (GDP) per capita of Singapore). CONCLUSION: The use of DCBA in BTK arteries in CLTI patients was not cost-effective compared with PTA. LEVEL OF EVIDENCE: 2, Randomized trial.

Clinical validation of an artificial intelligence-enabled wound imaging mobile application in diabetic foot ulcers.

There is a lifetime risk of 15% to 25% of development of diabetic foot ulcers (DFUs) in patients with diabetes mellitus. DFUs need to be followed up on and assessed for development of complications and/or resolution, which was traditionally performed using manual measurement. Our study aims to compare the intra- and inter-rater reliability of an artificial intelligence-enabled wound imaging mobile application (CARES4WOUNDS [C4W] system, Tetsuyu, Singapore) with traditional measurement. This is a prospective cross-sectional study on 28 patients with DFUs from June 2020 to January 2021. The main wound parameters assessed were length and width. For traditional manual measurement, area was calculated by overlaying traced wound on graphical paper. Intra- and inter-rater reliability was analysed using intra-class correlation statistics. A value of <0.5, 0.5-0.75, 0.75-0.9, and >0.9 indicates poor, moderate, good, and excellent reliability, respectively. Seventy-five wound episodes from 28 patients were collected and a total of 547 wound images were analysed in this study. The median wound area during the first clinic consultation and all wound episodes was 3.75 cm2 (interquartile range [IQR] 1.40-16.50) and 3.10 cm2 (IQR 0.60-14.84), respectively. There is excellent intra-rater reliability of C4W on three different image captures of the same wound (intra-rater reliability ranging 0.933-0.994). There is also excellent inter-rater reliability between three C4W devices for length (0.947), width (0.923), and area (0.965). Good inter-rater reliability for length, width, and area (range 0.825-0.934) was obtained between wound nurse measurement and each of the C4W devices. In conclusion, we obtained good inter-rater and intra-rater reliability of C4W measurements against traditional wound measurement. The C4W is a useful adjunct in monitoring DFU wound progress.

Clinical validation of a machine-learning-based handheld 3-dimensional infrared wound imaging device in venous leg ulcers.

Chronic venous insufficiency is a chronic disease of the venous system with a prevalence of 25% to 40% in females and 10% to 20% in males. Venous leg ulcers (VLUs) result from venous insufficiency. VLUs have a prevalence of 0.18% to 1% with a 1-year recurrence of 25% to 50%, bearing significant socioeconomic burden. It is therefore important for regular assessment and monitoring of VLUs to prevent worsening. Our study aims to assess the intra- and inter-rater reliability of a machine learning-based handheld 3-dimensional infrared wound imaging device (WoundAide [WA] imaging system, Konica Minolta Inc, Tokyo, Japan) compared with traditional measurements by trained wound nurse. This is a prospective cross-sectional study on 52 patients with VLUs from September 2019 to January 2021 using three WA imaging systems. Baseline patient profile and clinical demographics were collected. Basic wound parameters (length, width and area) were collected for both traditional measurements and measurements taken by the WA imaging systems. Intra- and inter-rater reliability was analysed using intra-class correlation statistics. A total of 222 wound images from 52 patients were assessed. There is excellent intra-rater reliability of the WA imaging system on three different image captures of the same wound (intra-rater reliability ranging 0.978-0.992). In addition, there is excellent inter-rater reliability between the three WA imaging systems for length (0.987), width (0.990) and area (0.995). Good inter-rater reliability for length and width (range 0.875-0.900) and excellent inter-rater reliability (range 0.932-0.950) were obtained between wound nurse measurement and each of the WA imaging system. In conclusion, high intra- and inter-rater reliability was obtained for the WA imaging systems. We also obtained high inter-rater reliability of WA measurements against traditional wound measurement. The WA imaging system is a useful clinical adjunct in the monitoring of VLU wound documentation.

Effectiveness of Comanagement Model: Geriatric Medicine and Vascular Surgery.

OBJECTIVES: Older surgical patients frequently develop postoperative complications due to their frailty and multiple comorbidities. Geriatric medicine consultation helps to optimize risk factors and improve outcomes in patients with hip fracture. This study aimed to evaluate patient outcomes before and after comanagement model implementation between geriatric medicine (Geriatric Surgical Service) and vascular surgery services. DESIGN: This was a case-control study involving emergency vascular surgical patients who were comanaged by vascular surgery, geriatric medicine, and geriatric nursing services. SETTINGS AND PARTICIPANTS: This study was conducted in a tertiary hospital in Singapore from 2015 to 2018 with acute vascular surgical patients aged older than 65 years. METHODS: A retrospective cohort of 135 patients from 2013 to 2014 (control group) who fulfilled the criteria for the comanagement model was compared with a prospective cohort of 348 patients who were comanaged by a geriatric surgical service from 2015 to 2018, and a further subgroup analysis of patients between 2015 and 2016 (n = 150) (early intervention group) and between 2017 and 2018 (n = 198) (late intervention group) was performed. RESULTS: Comanaged patients had a significantly shorter length of hospital stay (11.6 vs 20.8 days, P = .001), reduced nosocomial infections (3% vs 12% for urinary tract infection, P = .003) and decreased 30-day readmission rates (22% vs 34%, P = .011). A trend of a decreased incidence of fluid overload was noted in patients comanaged with the geriatric surgical service (3% vs 7%, P = .073). Subgroup analysis showed progressive reductions in the length of stay (15.4 vs 11.6 days, P = .001), 30-day readmission rate (35% vs 22%, P = .01), and nosocomial urinary tract infection (8% vs 3%, P = .003) between the early intervention group and the late intervention group. Although they were not statistically significant, reductions were also observed in the delirium rate (13% vs 11%) and other postoperative medical complications in the early intervention group and the late intervention group. CONCLUSION AND IMPLICATIONS: Despite having increasing comorbidities, older vascular surgical inpatients had a significantly shorter length of stay, reduced nosocomial infections, and decreased 30-day readmission rates through a comanagement model with vascular surgery and geriatric medicine services. Improvements in outcomes were observed over time as the model of care evolved. Geriatric medicine intervention in the perioperative period improves the outcomes of older acute vascular surgical patients.

Novel home use of mechanical negative pressure wound therapy in diabetic foot ulcers.

OBJECTIVE: Mechanical negative pressure wound therapy is an ultraportable, light weight and disposable single-use device that has been shown to promote wound healing. This study evaluated home use of a mechanically powered negative pressure wound therapy (NPWT) in diabetic foot wounds. METHODS: Patients underwent revascularisation and/or debridement or amputation before starting mechanical NPWT. Wound outcomes and images of the wounds were recorded at each follow-up visit by the wound nurse. Patients were followed up until wound closure or end of therapy. RESULTS: A total of 12 patients (each with one wound) were included in the study. Of the 12 wounds, 33.3% (n=4) of wounds achieved primary wound closure while the remaining 66.6% (n=8) of wounds demonstrated a mean wound size reduction of 37.5±0.13%. Of the closed wounds, mean time to healing was 4.75±2.50 weeks. There was 100% limb salvage with no further debridement or amputations, and no 30-day unplanned readmissions. Mean length of hospital stay before starting home NPWT was 9.75±6.31 days. Mean number of NPWT changes was 8.33±2.67 sessions, while mean duration of therapy was 4.0±1.54 weeks. Mean cost of home NWPT therapy was US$1904±731 per patient. CONCLUSION: The home use of mechanically powered NPWT in diabetic foot wounds demonstrated excellent wound healing rates and 100% limb salvage, with no complications.

Randomized Controlled Trial Comparing Drug-coated Balloon Angioplasty versus Conventional Balloon Angioplasty for Treating Below-the-Knee Arteries in Critical Limb Ischemia: The SINGA-PACLI Trial.

Background There is a paucity of randomized trials demonstrating superior efficacy of drug-coated balloon angioplasty (DCBA) compared with conventional percutaneous transluminal angioplasty (PTA) for below-the-knee arterial disease in patients with -critical limb ischemia. Purpose To compare DCBA versus PTA for below-the-knee lesions in participants with critical limb ischemia through 12 months. Materials and Methods In this prospective, randomized, two-center, double-blind superiority study, participants with critical limb ischemia with rest pain or tissue loss with atherosclerotic disease in the native below-the-knee arteries were randomly assigned (in a one-to-one ratio) to DCBA or PTA after stratification for diabetes and renal failure between November 2013 and October 2017. The primary efficacy end point was angiographic primary patency at 6 months analyzed on an intention-to-treat basis. Secondary end points through 12 months were composed of major adverse events including death and major amputations, wound healing, limb salvage, clinically driven target-lesion revascularization, and amputation-free survival. Primary and binary secondary end points, analyzed by using generalized-linear model and time-to-event analyses, were estimated with Kaplan-Meier survival curves and hazard ratios (Cox regression). Results Seventy participants (mean age, 61 years ± 10 [standard deviation]; 43 men) in the DCBA group and 68 (mean age, 64 years ± 10; 50 men) in the PTA group were evaluated. The percentage of patients with angiographic primary patency at 6 months was 43% (30 of 70) in the DCBA group and 38% (26 of 68) in the PTA group (P = .48). Through 12 months, the percentage of deaths was similar: 21% in the DCBA group and 16% in the PTA group (P = .43). Amputation-free survival rate assessed with Kaplan-Meier curves differed through 12 months: 59% (41 of 70) in the DCBA group compared with 78% (53 of 68) in the PTA group (P = .01). Conclusion In participants with critical limb ischemia, the drug-coated balloon angioplasty group and the conventional percutaneous transluminal angioplasty group had similar primary patency rates at 6 months after treatment of below-the-knee arteries. Amputation-free survival rates through 12 months were higher in the percutaneous transluminal angioplasty group. © RSNA, 2021 Online supplemental material is available for this article.

Outcomes of Catheter-Directed Thrombolysis for Arteriovenous Fistula Thrombosis in Singapore: Is It Still Relevant Today?

Objective: To review the outcomes of catheter-directed thrombolysis (CDT) for salvage of thrombosed arteriovenous fistula (AVF) in a single centre in Southeast Asia. Methods: A retrospective study of CDT in AVF between January 2015 and July 2018 at a tertiary university hospital was carried out. Results: Within the study period, 85 patients underwent CDT for AVF thrombosis. Of these patients, 78% underwent CDT for 24 h and 12% required CDT for 48 h. Moreover, 14% of patients had bleeding during CDT and hence required a decrease in dosing or complete cessation. Incidence of intracranial haemorrhage was 1%, and technical success was 92%. Post CDT, primary patency rates at 12, 24 and 36 months were 87%, 62% and 36%, respectively; assisted primary patency rates at 12, 24 and 36 months were 96%, 82% and 69%, respectively; and secondary patency rates at 12, 24 and 36 months were 99%, 93% and 86%, respectively. Multivariate analysis did not identify any predictive factors for patency post CDT. Conclusion: Within our study population, CDT for AVF salvage conferred good technical results with low rates of complications. There was good primary patency at 12 months, and the results were sustained up to 36 months. It remains a useful modality for fistula salvage, avoiding surgical intervention.

Transradial access for arteriovenous fistuloplasty in Singapore.

BACKGROUND: Endovascular balloon angioplasty is standard therapy for dysfunctional arteriovenous fistula in end-stage renal failure patients on hemodialysis. Venous antegrade or retrograde puncture of the fistula is typically performed to gain access for fistuloplasty. Transradial approach for brachiocephalic or brachiobasilic arteriovenous fistulas offers an alternative method of access with the advantage of addressing multi-focal juxta-anastomotic and venous stenosis from the same approach. We aim to review the efficacy, outcomes and complication rates of transradial access for arteriovenous fistuloplasty among patients in Singapore. METHODS: A retrospective review of 195 endovascular fistuloplasties from September 2017 to August 2019, at a tertiary university hospital Vascular Surgery unit. RESULTS: Of 195 fistuloplasties, 43 (22%) were transradial approach (23 brachiocephalic arteriovenous fistulas, 20 brachiobasilic arteriovenous fistulas) in 33 patients (67% male and mean age = 65 years). Of these 43 procedures, 11 (26%) were performed as balloon-assisted maturation fistuloplasties while 32 (74%) were performed for mature arteriovenous fistulas with multi-focal juxta-anastomosis and venous stenosis. Technical success rate was 95% with mean procedure duration at 43.5 ± 14.6 min. Mean pre- and post-fistuloplasty dialysis access flow rates increased from 502 to 952 ml/min (p < 0.001). Post-intervention primary patency was 100%, 66% and 20% at 1, 6 and 12 months, respectively. There were four patients with non-limb-threatening radial artery thrombosis (9.3%) while there was no radial artery pseudoaneurysm or post-procedural bleeding. CONCLUSION: Transradial approach for arteriovenous fistuloplasty is a safe and feasible option in patients requiring balloon-assisted maturation or with multi-focal juxta-anastomotic and venous stenosis.

Systematic review and meta-analysis of the prevalence of abdominal aortic aneurysm in Asian populations.

OBJECTIVE: The prevalence of abdominal aortic aneurysms (AAAs) is well reported in Western countries and AAA screening programs are well-established. However, although individual studies have reported that the prevalence of AAAs is lower in Asian populations, high-quality data on the prevalence of AAA in Asians are relative lacking. The present study aimed to systematically synthesize the data available in the literature and report the prevalence of AAAs in Asians. METHODS: An electronic search was performed using two major databases (PubMed and EMBASE) with no limitations imposed on the year of publication. The review conformed to the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines. Studies that reported the prevalence of AAAs in Asians were selected, and the population characteristics, AAA definition, method of screening, target population, and total number of patients screened were recorded. RESULTS: Our search yielded 157 unique articles. After a full-text review, 17 articles were included in the present study. All 17 studies of fair quality. The overall AAA prevalence was 1.30% (95% confidence interval [CI], 1.01%-1.59%) in Asian populations. The prevalence of AAAs was 2.56% (95% CI, 1.81%-3.31%) in Asian populations selected for cardiovascular risk factors and 0.61% (95% CI, 0.37%-0.85%) in Asian populations not selected for cardiovascular risk factors. CONCLUSIONS: The prevalence of AAAs in the general Asian population is low. However, the prevalence in Asian populations selected for cardiovascular risk factors approaches the prevalence of AAAs in Western populations. As such, screening for AAAs in carefully selected Asian male populations with cardiovascular risk factors could potentially yield benefits. Opportunistic screening for AAAs during ultrasound examination of the abdomen or transthoracic echocardiography for other indications could also be considered. However, further studies are needed to evaluate the potential benefits of screening for AAAs in carefully selected Asian populations.

Iliac vein pathology and short-term stenting outcomes in a South-East Asian population: A single-centre experience.

OBJECTIVE: Current literature regarding iliofemoral intervention and stenting is mostly based on Western populations. We present our experience of iliofemoral stenting for chronic venous disease within a South-East Asian population. METHODS: This is a single-centre retrospective review of a prospectively collected registry. Seventy-one patients with 105 limbs underwent iliac vein IVUS and stenting between 2016 and 2019. All patients underwent pre-procedure ultrasound venous scan and MRI venogram. Pre- and post-operative CEAP classification, Villalta score and Venous Clinical Severity Score (VCSS), technical results, stent patency rates and complication rates are documented. RESULTS: Seventy-six per cent of the cases are non-thrombotic iliac vein lesion, and 68% of patients have C4 to C6 disease. Ten percentage of patients had acute thrombosis on presentation. There was 100% technical success. A 6- and 7-point reduction in the mean VCSS and Villalta score, respectively, were noted post-stenting (baseline of 10 points and P < 0.001 in both categories). Post-stenting ulcer healing rate was 91% at 6 and 12 months. One-year ulcer recurrence and cellulites recurrence were at 8% and 7%, respectively. One unplanned 30-day readmission (not related to procedure) and no 30-day mortality were noted. Bleeding complication from anticoagulation was 3%. There was 10% in-stent non-flow limiting stenosis on surveillance. One-year primary patency was 91%, and secondary patency was 100%. CONCLUSION: Within our series, iliofemoral stenting has 100% technical success, with statistically significant reduction in VCSS and Villalta score, good wound healing rates, low ulcer and cellulites recurrence and good primary and secondary patency rates at 1 year.