Outcomes after endovascular revascularization for chronic limb-threatening ischemia from the only Vascular Quality Initiative (VQI) center in Asia.

OBJECTIVE: This study compares chronic limb-threatening ischemia disease characteristics and endovascular revascularization outcomes in a multi-ethnic Asian cohort vs their North American counterparts. METHODS: The Society for Vascular Surgery Vascular Quality Initiative (VQI) registry database from the first and currently the only VQI center in Asia was reviewed to identify patients with chronic limb-threatening ischemia 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: A total of 2862 endovascular revascularization procedures from our center were benchmarked against 129,347 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 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. CONCLUSIONS: Short-term outcomes of technical success and symptom relief in our center were comparable to benchmarked North American outcomes despite having a cohort with more diseased vessels, higher Wound, Ischemia, and foot Infection stages, and more 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.

Pilot single-arm study to investigate the efficacy and safety of endovenous Microwave ablations for treatment of varicose veins in Singapore - one year results of the MAESTRO registry.

OBJECTIVES: Aim was to report a prospective two-centre Singaporean experience using Endovenous Microwave Ablation (EMA) to treat symptomatic primary great saphenous vein reflux. We evaluated 1-year safety, efficacy and patient satisfaction. METHODS: 50 patients (63 limbs; 29 females; mean age 58.0 ± 12.1 years) were included. Patients were reviewed at 2-weeks, 3-, 6- and 12-months and underwent Duplex ultrasound assessment. Three quality of life (QoL) questionnaires were completed. RESULTS: The truncal closure rates at 2-weeks, 3-, 6- and 12-months were 63/63 (100%), 59/59 (100%), 58/58 (100%) and 59/60 (98.3%), respectively. There was 100% technical success and no serious adverse events. There were sustained improvement of QoL questionnaire scores from 2 weeks to 12 months. CONCLUSION: EMA is a safe and efficacious venous ablative technology at 12 months and is associated with a high rate of target vein occlusion and sustained QoL improvement.

Slow-flow phenomena following lower limb paclitaxel- and sirolimus-coated balloon angioplasty in the setting of chronic limb threatening ischaemia-a case series.

The Achilles heel of plain old balloon angioplasty (POBA) is neointimal hyperplasia (NIH) and restenosis, caused from the barotrauma of ballooning. Drug-coated balloons using a paclitaxel-based platform (PCB) have been shown to retard the restenotic process, using the anti-proliferative effects of paclitaxel, and give longer vessel patency. This is important in the setting of chronic limb threatening ischemia (CLTI) and for the protracted wound healing process in these frail patients. However, during PCB application, more than 50% of the drug is lost downstream, a phenomenon termed particulate embolization. This is thought to account for the slow- or no-flow phenomenon encountered after PCB use. Recent data suggest that slow-flow phenomenon was associated with a lower target lesion revascularisation rate and worse amputation free survival (AFS). The use of sirolimus coated balloons (SCB) to impede the NIH cascade has been less well studied but recent data suggested excellent short-term efficacy and found no slow flow phenomenon with their use in the tibial arteries in CLTI patients. Aim of this case series is to highlight the difference in flow phenomena using PCB and SCB elution in the setting of CLTI. We evaluated the use of parametric colour coding and time attenuation curves (TAC) as a quantitative measure of blood flow. SCB may have an advantage over PCB use in the peripheral vasculature because of a reduced incidence of slow flow phenomenon following drug elution.

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.

Early results of an Asian prospective multicenter VenaSeal real-world postmarket evaluation to investigate the efficacy and safety of cyanoacrylate endovenous ablation for varicose veins.

OBJECTIVE: The aim of A Singapore VenaSeal Real-World Post-Market Evaluation Study (ASVS) was to evaluate the performance of cyanoacrylate closure (CAC) for varicose veins in a prospective multiracial Singaporean Asian cohort. We report early clinical and patient satisfaction outcomes at 3 months after intervention. METHODS: There were 100 patients (151 legs; 156 truncal veins) who underwent CAC between April and December 2018. Of the 151 legs, 49 (32.5%) were treated for great saphenous vein (GSV) incompetence, 96 (63.6%) for bilateral GSV incompetence, 1 (0.7%) for small saphenous vein (SSV) incompetence, and 5 (3.3%) for combined unilateral GSV and SSV reflux. At baseline, 68 legs (45.0%) had C4 to C6 disease, and 67 legs (44.4%) had concomitant multiple stab avulsions. Patients were reviewed at 2 and 12 weeks by duplex ultrasound to check for venous recanalization (defined as ≥5 cm in length), pain score, revised Venous Clinical Severity Score, EuroQol-5 Dimension questionnaire score, Aberdeen Varicose Vein Questionnaire score, 14-item Chronic Venous Insufficiency Questionnaire (CIVIQ-14) for quality of life measures, and patient satisfaction. Time to return to work and normal activities were also recorded. RESULTS: There were 59 female patients, and mean age was 60.1 ± 12.7 years. There was 100% technical success. Patients tolerated the procedure well and reported low periprocedural pain (mean pain score, 2.9 [range, 0-9]). Patient surveys at the 3-month interval showed high satisfaction rates, with 72 of 91 (79.1%) being extremely or very satisfied. By day 10, of 100 patients, 93 (93%) resumed daily activities, whereas 36 (36%) had returned to work. At 2 weeks, GSV and SSV were completely occluded in 150 of 150 (100%) and 6 of 6 (100%) veins, respectively. At 3 months, GSV and SSV occlusion rates were 140 of 141 (99.3%) and 6 of 6 (100%), respectively. Transient superficial phlebitis was reported in 27 of 151 (18 %) legs, which was self-limited. At 3 months, revised Venous Clinical Severity Score improved from 5.00 (range, 1.00-18.00) to 1.00 (0.00-10.00; P < .001); EuroQol-5 Dimension score, from 0.686 (-0.382 to 1.00) to 1.00 (0.12-1.00; P < .001); Aberdeen Varicose Vein Questionnaire score, from 17.14 (1.29-61.15) to 4.83 (0.00-57.12; P < .001); and 14-item Chronic Venous Insufficiency Questionnaire, from 19.64 (1.79-73.21) to 7.14 (0.00-51.79; P < .001). CONCLUSIONS: CAC has a high safety profile and is an effective way to block refluxing truncal veins in Asian patients at early follow-up. Patients are highly satisfied and report low postoperative pain. There is significant continued quality of life improvement at 3 months. Early results are encouraging, but we await further prospective long-term follow-up from the study.

Use of the VENOVO™ and Sinus Obliquus™ venous stents in the treatment of non-thrombotic or post-thrombotic iliac vein lesions - Short-term results from a multi-centre Asian cohort.

OBJECTIVES: Deep venous stenting with intravascular ultrasound (IVUS) guidance is gaining favour as the treatment modality of choice for symptomatic ilio-femoral venous occlusive disease. The aim was to determine the short-term patency and symptomatic relief gained using the Bard Venovo™ and Optimed Sinus Obliquus™ stents in the endovascular treatment of non-thrombotic iliac vein lesions (NIVL) and post-thrombotic venous obstruction (PTO) from two Asian tertiary vascular centres. METHODS: Sixty patients (males = 21/60 (35.0%); median age 67 years (interquartile range 54-77)) who underwent IVUS interrogation and ilio-femoral stenting (June 2018-May 2019) in two Asian centres were prospectively followed. Clinical improvement was determined by the revised Venous Clinical Severity Score (rVCSS), pain using the Visual Analogue Scale (VAS) and ulcer healing rate. Patency rates were evaluated using Duplex ultrasound and computer tomography venogram. RESULTS: Seventy-one legs were interrogated and stented; 11/60 (18.3%) patients had a bilateral procedure. Indications for surgery were PTO (n = 11/71 (15.5%)) and NIVL (n = 60/71 (84.5%)). Twenty-seven of 71 (38.0%) patients had CEAP 6 disease. The median follow-up was 283 (interquartile range 211-370) days. Technical and procedural success was both 100%. Twenty-one of 71 (29.6%) legs had a combination of Venovo™ and Sinus Obliquus™ stents inserted for concurrent ilio-caval and iliac lesions. There were no major post-operative complications. Six-month primary, assisted primary and secondary patency rates were 94.1, 97.1 and 100%, respectively. There were no stent fractures. Mean rVCSS and VAS improved from 12.26 (±3.31) to 4.33 (±2.78) and 6.97 (±1.38) to 2.03 (±1.65), respectively, at three months (p < 0.01). Complete ulcer healing was seen in 27/27 (100%) patients at three months. CONCLUSION: Use of Venovo™ and Sinus Obliquus™ stents for symptomatic ilio-femoral venous disease showed excellent six-month primary patency rate with no stent fractures. There were significant clinical improvement and low-device-related complications. Longer follow-up is awaited to see how these dedicated venous stents perform.

Early (6 months) results of a pilot prospective study to investigate the efficacy and safety of sirolimus coated balloon angioplasty for dysfunctional arterio-venous fistulas: MAgicTouch Intervention Leap for Dialysis Access (MATILDA) Trial.

BACKGROUND: The aim of this pilot study was to evaluate the safety and efficacy of the MagicTouch™ sirolimus-coated balloon (SCB) catheter (Concept Medical Inc., Tampa, FL, US) on improving the patency of failing arterio-venous fistulas (AVF) with de novo and recurrent stenoses. MATILDA reports early outcomes at 3- and 6 months post intervention. METHODS: Single-centre, single-arm prospective pilot study of 33 (18 males; mean age 64.7±11.6 years) end-stage renal failure Asian patients with a dysfunctional AVF, who underwent SCB angioplasty between May 2019-January 2020. All procedures were performed under local anaesthetic without sedation and as day surgery. All patients were prescribed dual antiplatelet therapy for 3 months and followed up with Duplex ultrasound at 3 and 6 months. RESULTS: 47 stenotic target lesions treated and 24/33 (72.7%) patients were for restenosis. Main indications for intervention was low/dropping access flow (21/33; 63.6%) and most common target lesion was in the juxta-anastomosis (19/47; 40.4%). There was 100% technical and procedural success. There were no peri-procedural complications related to the SCB. The target lesion primary patency rates at 3 and 6 months were 46/47 (97.9%) and 29/35 (82.9%) respectively. Circuit access patency rates at 3 and 6 months were 31/33 (93.9%) and 17/25 (68%) respectively. There was one (2.9%) death at 6 months and 4/33 (12.1%) overall to date, all from patients' underlying co-morbidities. CONCLUSIONS: SCB angioplasty for dysfunctional AVF circuits is a safe and efficacious modality in Asian haemodialysis patients at six months comparable if not better than the paclitaxel data reported to date in the literature.

Does longitudinal or transverse orientation of the ultrasound probe improve cannulation success in minimally invasive venous surgery: A multicentre randomised controlled trial.

OBJECTIVE: This study evaluates the effect of transverse and longitudinal ultrasound transducer orientation on saphenous vein cannulation during endovenous ablation. METHODS: A single-blinded, multicentre, randomised controlled trial was performed in patients undergoing ultrasound-guided venous cannulation for saphenous ablation. The primary outcomes were overall cannulation success and time to successful cannulation. RESULTS: In total, 100 patients were assigned to parallel longitudinal orientation and transverse orientation groups. Cannulation success was 100%. There was no significant variation in time to cannulation detected between the transverse orientation and longitudinal orientation (85 s vs. 71 s, p = 0.314). Longitudinal orientation was associated with significantly fewer needle passes [median 3 (interquartile range 1-5) vs. 2 (interquartile range 1-3), p = 0.026] and less pain (median visual analogue scale score 1 vs. 2.5, p = 0.039) than those in the transverse orientation group. CONCLUSION: This trial has shown that while longitudinal orientation is associated with less procedural pain it has no significant effect on time to target vein cannulation during endovenous ablation.

The utility of endovenous cyanoacrylate glue ablation for incompetent saphenous veins in the setting of venous leg ulcers.

OBJECTIVE: Patients with venous leg ulcers (VLUs) represent the worse spectrum of chronic venous insufficiency (CVI). The Early Venous Reflux Ablation (EVRA) landmark trial published in 2018 demonstrated that early endovenous intervention results in faster healing of VLUs. We describe our post-EVRA experience using endovenous cyanoacrylate glue ablation (ECGA) to treat superficial venous reflux on an early basis and assess its efficacy and safety in the setting of VLUs. METHODS: There were 37 patients (39 legs, 43 truncal veins) with 43 discrete venous ulcers who underwent ECGA for CVI symptoms and VLUs. They received compression therapy and regular dressings for the VLUs postoperatively and were reviewed at 1 week, 3 months, 6 months, and 12 months after the procedure. Postoperative healing time for VLUs and complications were recorded along with the patient's satisfaction and postprocedure pain scores. RESULTS: The venous ulcers were all <30 cm2 before ECGA. The mean time for VLU healing from operation was 73.6 ± 21.9 days, and the primary occlusion rate of the CVI at both 1 week and 3 months was 100%. No major adverse events were observed except for one case of deep venous thrombosis. There was significant improvement in the revised Venous Clinical Severity Score postoperatively from 11 ± 1.63 (baseline) to 5.6 ± 1.37 (P < .001) at 3-month follow-up (on a scale of 0 to 27, with the severity of symptoms at a maximal 27). The visual analog scale scores for pain were low postoperatively, decreasing from a preoperative score of 6.84 ± 1.42 to 2.72 ± 1.59 (P < .001) at the 3-month follow-up (on a scale of 1-10, with 10 being the most severe pain). The median time to return to normal activities was 7 days (interquartile range, 5-7 days). CONCLUSIONS: ECGA together with compression therapy for VLUs is both safe and effective in this population of Asian patients. ECGA for patients with VLUs has excellent patient acceptability, minimal morbidity, and low recanalization rates at 12 months. Larger extensive studies and longer follow-up periods are required to validate the preliminary outcomes of this paper, and if it is proven to significantly improve ulcer healing rates, this will change the way we approach chronic venous ulceration.