Outcomes after Endovascular Revascularization for Chronic Limb Threatening Ischemia from the only Vascular Quality Initiative (VQI) Center in Asia.

INTRODUCTION: This study compares chronic limb-threatening ischemia (CLTI) disease characteristics and endovascular revascularization outcomes in a multi-ethnic Asian cohort versus their North American counterparts. METHODS: The Society for Vascular Surgery Vascular Quality Initiative (SVS VQI) registry database from the first and currently the only VQI center in Asia was reviewed to identify patients with CLTI who underwent endovascular revascularization between July 2019 and April 2024. Standardized VQI reporting variables were compared against benchmarks derived from all participating centers in North America. RESULTS: 2862 endovascular revascularization procedures from our center were benchmarked against 129347 procedures from 406 North American centers. Our cohort had a higher burden of comorbidities (diabetes mellitus, end-stage renal disease, cardiac disease) and presented with more advanced Wound, Ischemia, and Foot Infection (WIfI) stages. Our patients had more heavily calcified and longer (14.8 cm vs. 6.0 cm) diseased vessels with higher prevalence of multi-level (87% vs 54.6%), infrapopliteal (52.6% vs 38.9%) and inframalleolar (9.6% vs 2.4%) disease. Rates of technical success (92.7% vs 93%) and symptom improvement (39.1% vs 40.4%) were comparable between cohorts. However, 1-year mortality rates (28.9% vs 25.1%) and major amputation rates (13.3% vs 7.8%) were significantly higher. CONCLUSION: Short term outcomes of technical success and symptom relief in our center were comparable to benchmark North American outcomes despite having a cohort with more diseased vessels, higher WIfI stages and comorbidities. However, this cohort fared worse in longer term outcomes of 1-year mortality and major amputation rates. Further studies are required to elucidate the causes to improve these outcomes.

Investigating the effects of percutaneous endovascular aneurysm repair for abdominal aortic aneurysm on the lumen size of the common femoral artery.

BACKGROUND: Percutaneous endovascular aneurysm repair (PEVAR) is the definitive therapy of choice for abdominal aortic aneurysms worldwide. However, current literature regarding the anatomic changes in the common femoral artery (CFA) post-PEVAR is sparse and contradictory, and a significant proportion of these studies did not control for the potential confounding effects of ethnicity. Thus, this study aims to investigate the anatomical effects of PEVAR on the CFA using an Asian study cohort. METHODS: Between January 2019 and September 2023, the records of 113 patients who received PEVAR were reviewed. Groins with previous surgical interventions were excluded. The most proximate pre- and postoperative CT angiography of patients receiving PEVAR via the Perclose ProGlide™ Suture-Mediated Closure System were retrospectively analysed for changes in both the CFA inner luminal diameter (ID) and outer diameter (OD), the latter also encompassing the arterial walls. Access site complications within 3 months post-PEVAR were also recorded per patient. RESULTS: One hundred seventeen groins from 60 patients were included in this study, with 1 report of pseudoaneurysm. The CFA ID exhibited a 0.167 mm decrease (p-value = 0.0403), while the OD decreased by 0.247 mm (p-value = 0.0107). This trend persisted when the data was separately analysed with the common cardiovascular risk factors of diabetes mellitus, hypertension and hyperlipidaemia. CONCLUSION: Our analysis demonstrated a statistically significant decrease in the CFA diameters post-PEVAR. However, the percentage changes were below established flow-limiting values, as reflected by the single access site complication reported. Hence, our findings give confidence in the safety profile of this procedure, even with the reported smaller baseline CFA lumen size in Asians. Moving forward, similar longer-term studies should be considered to characterise any late postoperative effects.

Intervention with selution SLR™ Agent Balloon for Endovascular Latent Limus therapy for failing AV Fistulas (ISABELLA) Trial: Protocol for a pilot clinical study and pre-clinical results.

BACKGROUND: The aim of this pilot clinical study is to evaluate the safety and efficacy of the Selution Sustained Limus Release (SLR)™ sirolimus-coated balloon (M.A. MedAlliance SA, Nyon, Switzerland) for improving the patency of failing arterio-venous fistulas (AVF) in hemodialysis patients. We also present herein a pre-clinical pharmacokinetic and safety evaluation of Selution™ to justify its first use in hemodialysis patients for endovascular access salvage. METHODS AND RESULTS: This is an investigator-initiated prospective single-center, non-blinded single-arm trial. Forty patients with clinically significant de novo or recurrent stenoses in a mature AVF circuit will be recruited. All stenotic lesions will be prepared with high pressure non-compliant conventional balloon angioplasty (CBA) prior to deployment of the Sustained-Release Selution™ sirolimus drug-eluting balloon. The primary efficacy endpoint is 6-month target lesion primary patency and the primary safety endpoint is freedom from localized or systemic serious adverse events through 30 days. Secondary endpoints of interest include technical and clinical success rates and circuit access patency at 3 and 6 months. Follow-up will occur for 2 years for those patients whose AVFs remain patent. Pharmacokinetic and histological animal safety studies performed with the Selution™ coating formulation showed prolonged arterial tissue retention of sirolimus with therapeutic levels up to 60 days and non-toxic and rapidly declining blood levels. Histological results in animal models demonstrated safety, freedom from intraluminal thrombus, reduction in restenosis by sirolimus elution compared to CBA, and no evidence of embolic phenomena indicative of adverse particulate effects. DISCUSSION: Long release sirolimus coated balloons may serve as a promising novel alternative therapy to paclitaxel-based technology for treating conduit stenosis secondary to neointimal hyperplasia. Pre-clinical pharmacokinetic and histological animal data are encouraging and provide suggestion of safety and efficacy in this setting. This single-center trial will provide a first step toward demonstration of efficacy and safety of this device for treatment of stenotic fistulas.

Maggot debridement therapy in the tropics - Preliminary outcomes from a tertiary hospital.

This paper aimed to describe the clinical outcomes and patients' acceptance of Maggot debridement therapy (MDT) at a tertiary hospital in Singapore. Patients with non-viable tissue (NVT) covering at least 25% of wound bed on lower limbs and/or unable to tolerate sharp debridement at the bedside were recruited between January and August 2021. Sterile medical-grade maggots of Lucilla Cuprina were used. Wound specialist nurses assessed the size and wound to determine the type of MDT, either Baggots or free-range larvae (FRL), and the number of maggots required prior to commencement of therapy. Wound sites were measured and photographed at multiple time points: before the start of MDT therapy, during the wound review at 48 or 72 h after each cycle of MDT and completion of therapy. Three patients received Baggot therapy, while the remaining 11 received FRL therapy. The mean age for patients receiving Baggot and FRL were 78.3 (SD = 10.6) and 63.6 (11.4), respectively. Each patient received three cycles of MDT treatment on average. The most common type of wound was ray amputated toe wounds (n = 8), while the most common wound aetiology was arterial ulcerations (n = 12). A reduction of NVT was observed in 11 out of 14 patients, and ten of these 11 patients achieved successful debridement (at least 25% reduction in NVT). Five out of 14 patients had to undergo amputation within the same admission due to poor wound healing, and 60% of these five patients failed to achieve successful debridement. MDT was quite well-accepted by the patients, and they felt some improvement in their wounds. MDT can facilitate wound healing through successful debridement and potentially reduce the need for amputation. Further research needs to be done regarding the type of MDT that is optimal to use in tropical countries with high humidity.

SIroliMus coated angioPlasty versus plain balloon angioplasty in the tREatment of dialySis acceSs dysfunctION (IMPRESSION): study protocol for a randomized controlled trial.

BACKGROUND: Percutaneous transluminal angioplasty is the current standard treatment for arteriovenous fistula (AVF) stenosis. The mid- and long-term patency with plain balloon angioplasty (PBA) is however far from satisfactory. While paclitaxel-coated balloon angioplasty has been shown to be superior to PBA, concern over its safety profile has recently arisen after a reported possible increased mortality risk with a meta-analysis of large lower limb studies. An angioplasty balloon with a new type of drug coating, the sirolimus-coated balloon (SCB), has been proven to improve patency in the coronary arteries. However, its effect on AV access has yet to be studied. METHODS/DESIGN: This is an investigator-initiated, prospective, multicenter, double-blinded, randomized controlled clinical trial to assess the effectiveness of SCB compared to PBA in improving the patency of AVF after angioplasty. A total of 170 patients with mature AVF that requires PTA due to AVF dysfunction will be randomly assigned to treatment with a SCB or PBA at a 1:1 ratio, stratified by location of AVF and followed up for up to 1 year. The inclusion criteria include [1] adult patient aged 21 to 85 years who requires balloon angioplasty for dysfunctional arteriovenous fistula [2]; matured AVF, defined as being in use for at least 1 month prior to the angioplasty; and [3] successful angioplasty of the underlying stenosis with PBA, defined as less than 30% residual stenosis on digital subtraction angiography (DSA) and restoration of thrill in the AVF on clinical examination. The exclusion criteria include thrombosed or partially thrombosed access circuit at the time of treatment, presence of symptomatic or angiographically significant central vein stenosis that requires treatment with more than 30% residual stenosis post angioplasty, and existing stent placement within the AVF circuit. The primary endpoint of the study is access circuit primary patency at 6 months. The secondary endpoints are target lesion primary patency; access circuit-assisted primary patency; access circuit secondary patency at 3, 6, and 12 months; target lesion restenosis rate at 6 months; total number of interventions; complication rate; and cost-effectiveness. The trial is supported by Concept Medical. DISCUSSION: This study will evaluate the clinical efficacy and safety of SCB compared to PBA in the treatment of AVF stenosis in hemodialysis patients. TRIAL REGISTRATION: ClinicalTrials.gov NCT04409912 . Registered on 1 June 2020.

Distribution of Peripheral Arterial Disease in Patients Undergoing Endovascular Revascularization for Chronic Limb Threatening Ischaemia: Insights from the Vascular Quality Initiative in Singapore.

This study aimed to examine the distribution of lower limb atherosclerotic lesions in a multi-ethnic Asian cohort with chronic limb threatening ischemia (CLTI) from Singapore. The Society for Vascular Surgery Vascular Quality Initiative registry database was used to identify 265 CLTI patients who underwent percutaneous angioplasty between June 2019 and December 2019, of whom 171 (64.5%) were male, and the mean age was 67.9±11.0 years. The majority were diabetic (84.5%) and 145 (54.7%) had chronic kidney disease (CKD). The majority of the lower limb atherosclerotic lesions were de novo lesions (598/797, 75.0%), predominantly TransAtlantic Inter-Society Consensus II C/D (451/797, 56.6%), and were moderately to severely calcified (76.3%). The anterior tibial artery and femoral-popliteal artery were the most commonly affected vessels. The mean length of the treated lesions was 14.5±13.7 cm. There was a tendency, albeit insignificant, of multi-level disease in those who were diabetic or had CKD.

World's First Experience Treating TASC II C and D Tibial Occlusive Disease Using the Selution SLR Sirolimus-Eluting Balloon: Six-Month Results From the PRESTIGE Study.

PURPOSE: The performance of sirolimus-coated devices has not been studied in patients with chronic limb-threatening ischemia patients. PRESTIGE aims to investigate the 6-month efficacy and safety profile of the Selution Sustained Limus Release (SLR) sirolimus-eluting balloon for treatment of TASC II C and D tibial occlusive lesions in patients with CLTI. MATERIALS AND METHODS: PRESTIGE is a pilot prospective, nonrandomized, single-arm, multi-investigator, single-center clinical study. Endpoints were adverse event-free survival at 1 month, technical success rate, primary tibial patency at 6 months, limb salvage success, target lesion revascularization (TLR), and amputation free survival (AFS). RESULTS: A total of 25 patients were included. There were 17 (68.0%) males; mean age, 63.7±9.73 years. CLTI severity was based on the Rutherford scale (R5=25/25; 100.0%). Significant comorbidities included diabetes mellitus (n=22; 88.0%) and end-stage renal failure (n=11; 44.0%). A total of 33 atherosclerotic lesions were treated (TASC II D=15 (45.5%)). Mean lesion length treated was 191±111 mm. Technical success was 100%. Primary tibial patency at 6 months was 22/27 (81.5%) and freedom from clinically driven TLR was 25/30 (83.3%). AFS was 21/25 (84.0%; 3 deaths and 1 major lower extremity amputation). Mean Rutherford score improved from 5.00 at baseline to 1.14±2.10 (p<0.05) at 6 months. There was a wound healing rate of 13/22 (59.1%) and 17/21 (81.0%) at 3 and 6 months respectively. CONCLUSIONS: Selution SLR drug-eluting balloon is a safe and efficacious modality in treating complex tibial arterial occlusive lesions in what is an otherwise frail cohort of CLTI patients, with a high prevalence of diabetes and end-stage renal failure. Technical and clinical success rates are high and 6-month target lesion patency and AFS are more than satisfactory.

Exit site complications following cyanoacrylate glue endovenous ablation of incompetent truncal veins for chronic venous insufficiency.

In the last 5 years, the use of nonthermal, nontumescent endovenous ablation such as cyanoacrylate glue (CAG) for treatment of chronic venous insufficiency has gained global popularity. This case series discusses the presentation and management of delayed access sheath site infections in patients who have undergone CAG therapy. The authors believe such adverse effects are related to granuloma formation owing to a hypersensitivity reaction to CAG at the puncture exit site. The endovenous surgeon should be aware of preventing glue spillage into the subcutaneous space at the access site during treatment, to minimize the risk of this complication developing.

Maximally Disfiguring Surgery for Forefoot Osteomyelitis: Time for a Rethink?

The treatment of choice for diabetic foot osteomyelitis is surgical debridement and targeted antibiotics with or without revascularization, depending on vascular status. In our society, debridement is done by either a vascular or orthopedic surgeon, and the common teaching is that generous amputation of bone with the accompanying soft tissue envelope is essential for adequate source control and to prevent recurrence (which remains as high as 30% even with this approach). Most of our patients undergo formal ray amputation through the metatarsal neck, while a few get digital amputations through the interphalangeal joints. Many of the resultant wounds cannot be closed and are left to heal by secondary intention. These amputations invariably alter the biomechanics of the foot and leave large and slow-healing open wounds, which have associated adverse psychosocial impacts. We describe 2 cases of patients who had osteomyelitis in the region of the forefoot who underwent complete bony resections of the osteomyelitis but with sparing of the soft tissue envelopes with good outcomes, and we challenge the dogma that maximal debridement of soft tissue must accompany debridement of necrotic and infected bone.

Microarray profiling shows distinct differences between primary tumors and commonly used preclinical models in hepatocellular carcinoma.

BACKGROUND: Despite advances in therapeutics, outcomes for hepatocellular carcinoma (HCC) remain poor and there is an urgent need for efficacious systemic therapy. Unfortunately, drugs that are successful in preclinical studies often fail in the clinical setting, and we hypothesize that this is due to functional differences between primary tumors and commonly used preclinical models. In this study, we attempt to answer this question by comparing tumor morphology and gene expression profiles between primary tumors, xenografts and HCC cell lines. METHODS: Hep G2 cell lines and tumor cells from patient tumor explants were subcutaneously (ectopically) injected into the flank and orthotopically into liver parenchyma of Mus Musculus SCID mice. The mice were euthanized after two weeks. RNA was extracted from the tumors, and gene expression profiling was performed using the Gene Chip Human Genome U133 Plus 2.0. Principal component analyses (PCA) and construction of dendrograms were conducted using Partek genomics suite. RESULTS: PCA showed that the commonly used HepG2 cell line model and its xenograft counterparts were vastly different from all fresh primary tumors. Expression profiles of primary tumors were also significantly divergent from their counterpart patient-derived xenograft (PDX) models, regardless of the site of implantation. Xenografts from the same primary tumors were more likely to cluster together regardless of site of implantation, although heat maps showed distinct differences in gene expression profiles between orthotopic and ectopic models. CONCLUSIONS: The data presented here challenges the utility of routinely used preclinical models. Models using HepG2 were vastly different from primary tumors and PDXs, suggesting that this is not clinically representative. Surprisingly, site of implantation (orthotopic versus ectopic) resulted in limited impact on gene expression profiles, and in both scenarios xenografts differed significantly from the original primary tumors, challenging the long-held notion that orthotopic PDX model is the gold standard preclinical model for HCC.