An Observational Clinical Trial Examining the Effect of Topical Oxygen Therapy (Natrox™) on the Rates of Healing of Chronic DiAbetic Foot Ulcers (OTONAL Trial)

Natrox™ topical oxygen therapy (TOT) (Inotec AMD Ltd, Cambridgeshire, UK) employs a small battery-powered "oxygen generator" to concentrate atmospheric oxygen and feeds pure, moist, oxygen through a fine, soft tube to a dressing-like "oxygen distribution system", which is placed over the wound and is held in place by a conventional dressing. The aim was to determine the effectiveness of Natrox™ for non-healing diabetic foot ulcers (DFU) over a 3-month period.Longitudinal, single-arm, open prospective registry study using 12 weeks of TOT using a 4 week run-in period. 20 patients recruited to OTONAL had chronic DFU greater than 3 months duration or minor amputation sites with less than 50% healing in 4 weeks.There were 13 (65%) males and the mean age was 65.7 (±11.6) years. The mean glycated haemoglobin (HbA1c) was 6.9 (±1.3) mmol mol-1 and mean wound duration before TOT was 114 (±79.1) days. 18/20 (90.0%) patients had concomitant lower limb revascularization angioplasty for chronic limb threatening ischaemia. The mean size of the foot ulcer at baseline was 11.3 ± 14.8 cm2 and mean transcutaneous oxygen measurement value was 34.1 (±19.6) mm Hg. Wound closure of >75% was observed in 14/20 (70.0%) patients. There was a 91.3% (±14.9%) wound area reduction by 3 months (P = .001) and mean time for 100% closure was 77.6 ± 32.5 days. Mean pain scores reduced from 2.4 (±1.8) at baseline to .5 (±1.0) at 3 months (P = .008). All patients were very satisfied using the ambulatory device. Use of TOT in chronic diabetic foot wounds stimulates a healing state, underpinning the concept that oxygen plays a central role in wound healing. Our results are more compelling if you consider they started with relatively large-sized DFUs and majority of patients were frail with underlying peripheral artery disease. (NCT03863054).

3-year clinical outcomes of A Singapore VenaSeal™ real world post-market evaluation Study (ASVS) for varicose vein ablation

INTRODUCTION

Medium-term clinical outcome data are lacking for cyanoacrylate glue (CAG) ablation for symptomatic varicose veins, especially from the Asian population.

OBJECTIVES

Aim was to determine the 3-year symptomatic relief gained from using the VenaSeal™ device to close refluxing truncal veins from the Singaporean ASVS prospective registry.

METHODS

The revised Venous Clinical Severity Score (rVCSS) and three quality of life (QoL) questionnaires were completed to assess clinical improvement in venous disease symptoms along with a dedicated patient satisfaction survey. 70 patients (107 limbs; 40 females; mean age of 60.9 ± 13.6 years) were included at 3 years.

RESULTS

At 3 years, rVCSS showed sustained improvement from baseline (5.00 to 0.00; p < 0.001) and 51/70 (72.9%) had improvement by at least 2 or more CEAP categories. Freedom from reintervention was 90% and 85.7% patients were extremely satisfied with the treatment outcome. No further reports of further hypersensitivity reactions after one year.

CONCLUSION

The 3-year follow-up results of the ASVS registry demonstrated continued and sustained clinical efficacy with few reinterventions following CAG embolization in Asian patients with chronic venous insufficiency.

TRIAL REGISTRATION

ClinicalTrials.gov Registration: NCT03893201.

MagicTouch PTA Sirolimus-Coated Balloon for Femoropopliteal and Below-the-Knee Disease: 3-Year Outcomes of the XTOSI Trial

BACKGROUND

Sirolimus-coated balloon (SCB) is a potential treatment option for peripheral arterial disease (PAD). There are currently no long-term clinical data for this novel treatment for PAD. We present the 3-year results of the first-in-human study of MagicTouch PTA SCB for treatment of PAD for both femoropopliteal and below-the-knee arteries.

METHODS

The XTOSI pilot study is a prospective, single-arm, open-label, single-center trial evaluating MagicTouch PTA SCB for symptomatic PAD. Assessments through 3 years included freedom from clinically driven target lesion revascularization (CD-TLR), freedom from major amputation, amputation-free survival (AFS), overall survival, and ulcer-free status.

RESULTS

At 3 years, the overall freedom from CD-TLR was 84.4%, freedom from major amputation was 86.1%, AFS was 63.3%, overall survival was 63.3%, and ulcer-free status in remaining survivors with intact limbs was 100%. For femoropopliteal lesions, at 3 years, the freedom from CD-TLR was 92.9%, freedom from major amputation was 93.3%, AFS was 70%, and overall survival was 70%. For below-the-knee lesions, at 3 years, the freedom from CD-TLR was 77.8%, freedom from major amputation was 81.0%, AFS was 58.6%, and overall survival was 58.6%.

CONCLUSIONS

SCB in the XTOSI pilot study showed promising clinical results sustained to 3 years, and no long-term safety concerns were raised. Randomized trials are currently ongoing to investigate the safety and efficacy of SCB for treatment of PAD.

Study protocol for a Prospective, Randomized controlled trial of stEnt graft and Drug-coated bAlloon Treatment for cephalic arch stenOsis in dysfunctional arteRio-venous fistulas (PREDATOR)

BACKGROUND

Treatment of cephalic arch stenosis (CAS) is associated with high risk of failure and complications. Although stent-graft (SG) placement has improved patency rates, stent edge restenosis has been raised as a potential limiting factor for SG usage in CAS. This study aims to evaluate the safety and efficacy of combining stent graft placement with paclitaxel-coated balloon (PCB) angioplasty versus PCB alone in the treatment of CAS.

METHODS

This is an investigator-initiated, prospective, international, multicenter, open-label, randomized control clinical trial that plans to recruit 80 patients, who require fistuloplasty from dysfunctional arteriovenous fistula (AVF) from CAS. Eligible participants are randomly assigned to receive treatment with SG and PCB or PCB alone in a 1:1 ratio post-angioplasty (n = 40 in each arm). Randomization is stratified by de novo or recurrent lesion, and the participants are followed up for 1 year. The primary endpoints of the study are target lesion primary patency (TLPP) and access circuit primary patency (ACPP) rates at 6-months. The secondary endpoints are TLPP and ACPP at 3- and 12-month; target lesion and access circuit assisted primary and secondary patency rates at 3, 6, and 12-months and the total number of interventions; complication rate; and cost-effectiveness.

DISCUSSION

This study will evaluate the clinical efficacy and safety of combination SG and PCB implantation compared to PCB alone in the treatment of CAS for hemodialysis patients.

Sirolimus-coated balloon angioplasty in maintaining the patency of thrombosed arteriovenous graft: 1-year results of a prospective study

BACKGROUND

A prospective, pilot study was designed to test the feasibility of using sirolimus-coated balloon (SCB) to treat graft vein junction of thrombosed arteriovenous graft (AVG) following successful pharmacomechanical thrombectomy. The present report provides the 1-year results of this study.

METHODS

This is a 1-year follow-up of a single, prospective, single-arm study that was conducted from 2018 to 2019 in 20 patients who presented to a tertiary institution with thrombosed AVG. The recruited patients received SCB angioplasty at the graft-vein junction following successful endovascular thrombectomy of a thrombosed AVG. One year after recruitment, there were three deaths, one AVG revision, and one AVG explantation among the participants recruited. The outcomes of 15 subjects at 1-year following the index procedure obtained from electronic medical records were re-examined.

RESULTS

The 1-year access circuit primary patency rate was 40%, while assisted primary and secondary patency rates were 46.7% and 73.3%, respectively. A total of 16 interventions (4 angioplasties, 12 thrombectomies) were performed in 9 patients over the 12 months. Four AVGs were abandoned. The median number of interventions per patient was 1 (0-3) per year. Using Kaplan-Meier analysis, the mean estimated post-intervention access circuit primary patency was 230 (95% CI: 162-300) days, while access circuit assisted primary patency was 253 (95% CI: 187-320) days, and access circuit secondary patency was 292 (95% CI: 230-356) days. Sub-group analysis did not show a significant difference in the mean estimated primary patency between AVG with de novo and recurrent stenosis (245 days, 95% CI: 151-339 vs 210 days, 95% CI: 113-307; p = 0.29).

CONCLUSIONS

SCB may help sustain the patency of thrombosed AVG following successful thrombectomy.

A case of severe polyarteritis nodosa with critical limb threatening ischemia-promising treatment with sirolimus drug-coated angioplasty

Polyarteritis nodosa (PAN) is a rare form of vasculitis. Acute limb ischemia is a rare presentation and complication of PAN. Plain old balloon angioplasty (POBA) is one of the treatment strategies for addressing PAN-related critical limb threatening ischemia (CLTI). However, recurrence of stenosis and occlusion is frequent, making POBA a poor treatment choice, as evidenced in our described clinical case. Consequently, with consideration of sirolimus's anti-inflammatory and immunosuppressive properties, we used a sirolimus-coated balloon in the treatment of PAN-induced CLTI. A 37-year-old woman first presented with acute limb ischemia as her initial symptom. Diagnostic angiography demonstrated occlusion of her tibial vessels, and POBA was performed to restore perfusion. Later in the course of her illness, she developed foot gangrene despite multiple courses of immunosuppressive drugs and several attempts with POBA to achieve limb salvage. Because of her disease trajectory, a MagicTouch (Concept Medical) sirolimus-coated balloon was deployed to her anterior tibial artery during her third angioplasty. At 17 months after her last angioplasty, she remained ulcer free, and surveillance scans demonstrated occlusion-free tibial vessels. The use of sirolimus-coated balloon angioplasty is a promising treatment approach for successful limb salvage in patients with PAN vasculitis and CLTI.

USE of IMplanting the Biotronik PassEo-18 Lux drug coated balloon to treat failing haemodialysis arteRiovenous FIstulas and grafts (SEMPER FI Study)

BACKGROUND

Plain old balloon angioplasty has been the mainstay of treatment for arteriovenous fistula (AVF) stenoses. Recent studies suggest that drug coated balloons (DCB) may significantly reduce re-intervention rates on native and recurrent lesions. The Passeo-18 Lux DCB (Biotronik AG, Buelach, Switzerland) is packaged with a 3.0 µg/mm2 dose of paclitaxel. The hypothesis is that its use provides better target lesion primary patency (TLPP), primary assisted patency (PP), secondary patency (SP) rates and reduces the number of visits for re-intervention in a cohort of patients with stenotic AVF and arteriovenous grafts (AVGs).

METHODS

The USE of IMplanting the Biotronik PassEo-18 Lux DCB to treat failing haemodialysis arteRiovenous FIstulas and grafts trial (SEMPER FI) was a prospective double-centre, multi-investigator, non-consecutive, non-blinded single-arm study investigating the efficacy and safety of the Passeo-18 Lux DCB in patients with stenotic AVF/AVG lesions between January 2021 and January 2022. Patient demographics, clinical characteristics, vascular access history, operative indications, details and outcomes were collected prospectively. TLPP, circuit access primary patency (CAP), PP, SP and deaths 6- and 12-months post-intervention were studied.

RESULTS

Ninety-one patients with 110 lesions were recruited across the two centres. 62.6% (n = 57) were male with a median age of 63.5 years (SD = 10.5). 62.6% (n = 57) were taking anti-platelets. Eighty-five AVFs and six AVGs were treated. 60% (n = 54) of AVFs intervened were radiocephalic. 52.7% (n = 58) of targeted lesions were juxta-anastomotic stenosis (JAS) and one-third (n = 33) at the AVF/AVG outflow. 70.9% (n = 78) of lesions were recurrent. Median time from last intervention was 219 days. 78% of target lesions (n = 85) and circuits (n = 70) were patent at 6-months, of which 96.7% (n = 87) of those requiring assisted intervention were patent.

CONCLUSION

This study shows that the Passeo-18 Lux DCB can be an effective and safe tool in the treatment of failing haemodialysis AVFs/AVGs.

Use of the helical SUPERA™ stent and Passeo-18 Lux™ drug-coated balloon to treat recurrent cephalic arch stenosis for dysfunctional brachiocephalic fistulas: 1 year results of the Arch V SUPERA-LUX study

BACKGROUND

Aim of Arch V SUPERA-LUX was to evaluate the safety and efficacy of the combination therapy of SUPERA™ (Abbott Vascular, Santa Clara, CA, USA) helical stent implantation and Passeo-18 Lux™ (Biotronik Asia Pacific Pte Ltd, Singapore) drug coated balloon (DCB) elution to treat recurrent cephalic arch stenosis (CAS) in the setting of AV access dysfunction.

METHODS

Investigator-initiated, single-center, single-arm prospective pilot study of 20 end-stage renal failure Asian patients with a dysfunctional brachiocephalic fistula. All had symptomatic recurrent CAS within 6 months of prior intervention. The lesion was pre-dilated with a standard high-pressure balloon (Biotronik Passeo-35 HP balloon). The DCB (Passeo-18 Lux™) is subsequently inflated and the SUPERA™ stent deployed to sit 2 mm distal to the cephalic arch and covering the CAS but within the DCB zone. All patients were prescribed dual antiplatelet therapy for 3 months and followed up with Duplex ultrasound at 6- and 12-months.

RESULTS

There were 9 (45%) males and mean age was 67 ± 11.0 years. Mean time from prior procedure was 113 ± 68 days and main indication for reintervention was high venous pressure (9/20, 45%). Technical success was 100% and there were no peri-procedural complications related to either stent or DCB deployment. Target lesion primary patency at 6- and 12-months was 10/18 (55%) and 5/16 (31%), respectively. Mean time to target lesion re-intervention was 170 ± 82 days. Circuit access patency was 8/18 (44%) and 2/16 (13%) at 6- and 12-months respectively and mortality was 3/20 (15%) attributed to the patients' underlying co-morbidities.

CONCLUSION

Dual prong strategy of using SUPERA™ stenting and Passeo-18 Lux™ drug elution for recurrent CAS, although safe, was no more efficacious than conventional balloon angioplasty or stenting alone. Development of an intense inflammatory reaction within the stent led to reinterventions of a number of cases with suboptimal results.

Polymer-coated paclitaxel-eluting stents for the treatment of stenosed native arteriovenous fistulas: Long-term results from the ELUDIA study

BACKGROUND

Percutaneous transluminal angioplasty is the preferred treatment of stenosed failing arteriovenous fistulas (AVF) but is hampered by increasing rates of vascular restenosis because of development of myointimal hyperplasia.

METHODS

This multicenter observational study of polymer-coated low-dose paclitaxel-eluting stents (ELUvia stents by Boston Scientific) in stenosed AVF undergoing hemoDIAlysis (ELUDIA) was jointly conducted in three tertiary hospitals from Greece and Singapore. Failure of AVF was defined according to K-DOQI criteria and significant fistula stenosis (>50%DS by visual estimate) was determined with subtraction angiography. Patients were considered for ELUVIA stent insertion based on significant elastic recoil following balloon angioplasty for the treatment of a single vascular stenosis within a native AVF. The primary outcome measure was sustained long-term patency of the treated lesion/fistula circuit defined as successful stent placement with resumption of uninterrupted hemodialysis and without significant vascular restenosis (50%DS threshold) or other secondary interventions during follow-up.

RESULTS

Some 23 patients received the ELUVIA paclitaxel-eluting stent (eight radiocephalic, 12 brachiocephalic, and three transposed brachiobasilic native AVFs). Mean AVF age at the time of failure was 33.9 ± 20.4 months. Treated lesions included 12 stenoses at the juxta-anastomotic segment, nine at the outflow veins, and two cephalic arch lesions with a mean diameter stenosis of 86 ± 8%. Median stent diameter and length used were 7 mm and 40 mm, respectively. After a median follow-up period of 20 months, some 18 stents out of 23 cases remained patent (cumulative rate 78.3%) without any clinical or imaging evidence of recurrent stenosis. Estimated primary patency of the ELUVIA stents was 80.6% and of the corresponding fistula circuit 65.1% at 2 years by Kaplan-Meier methods.

CONCLUSIONS

This observational study has shown promising long-term results of polymer-coated paclitaxel-eluting stents for the treatment of failing arteriovenous fistulas. Large-scale controlled studies are necessary.

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.

One year clinical outcomes of Rutherford 6 chronic limb threatening ischemia patients undergoing lower limb endovascular revascularisation from Singapore

Background

Percutaneous transluminal angioplasty (PTA) is widely used as a first-line revascularisation option in patients with chronic limb threatening ischemia (CLTI). This study aimed to evaluate the short-term endovascular revascularisation treatment outcomes of a cohort of Rutherford 6 (R6) CLTI patients, from a multi-ethnic Asian population in Singapore.

Patients with R6 CLTI who underwent endovascular revascularisation from June 2019 to February 2020 at Singapore General Hospital, a tertiary vascular centre in Singapore, were included and followed up for one year. Primary outcome measures included number and type of reinterventions required, 3-, 6- and 12-month mortality, 6- and 12-month amputation free survival (AFS), wound healing success and changes in Rutherford staging after 3, 6 and 12 months.

Results

Two hundred fifty-five procedures were performed on 86 patients, of whom 78 (90.7%) were diabetics, 54 (62.8%) had coronary artery disease (CAD) and 54 (62.8%) had chronic kidney disease (CKD). 42 patients (48.8%) required reintervention within 6 months. Multivariate analysis revealed that the presence of CAD was a significant independent predictor for reintervention. Mortality was 15.1%, 20.9% and 33.7% at 3, 6 and 12 months respectively. AFS was 64.0% and 49.4% at 6 and 12 months. Inability to ambulate, congestive heart failure (CHF), dysrhythmia and CKD were significant independent predictors of lower 12-month AFS.

Conclusions

PTA for R6 CLTI patients was associated with relatively high mortality and reintervention rates at one year. CAD was an independent predictor of reintervention. More research is required to help risk stratify which CLTI patients would benefit from an endovascular-first approach versus conservative treatment or an immediate major lower extremity amputation policy.

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.

Midterm outcomes (2 years) using the Venovo™ and Sinus Obliquus™ venous stents in the treatment of non-thrombotic and post-thrombotic iliac vein lesions – Results from a multi-centre Asian cohort

Introduction

Medium-term outcome data are lacking for dedicated venous stents especially from the Asian population.

Objectives

Aim was to determine the 2-year patency and symptomatic relief gained from using the BD Venovo™ and Optimed Sinus Obliquus™venous stents for ilio-femoral obstruction (IFO).

Methods

60 patients (71 limbs; 39 females; mean age of 66.4 ± 11.9 years) were included in this prospective dual centre Asian cohort. Clinical improvement was determined by change in the CEAP, rVCSS and pain scores. Stent patency and stenosis were measured using area reduction on CTV and diameter reduction on Duplex ultrasound.

Results

At 2 years, 65.7% showed ≥1 CEAP score improvement from baseline and rVCSS and pain scores remained low and sustained. 87.1% venous leg ulcers remained healed. Freedom from target lesion revascularisation was 94.3% and overall stent patency was 87.1%. There were no stent fractures or migration reported.

Conclusion

Dedicated venous stents for IFO were associated with sustained clinical improvement and a high freedom from reintervention at 2 years in Asian patients.

Pain Outcomes Following Mechanochemical Ablation vs Cyanoacrylate Adhesive for the Treatment of Primary Truncal Saphenous Vein Incompetence: The MOCCA Randomized Clinical Trial

Importance

Endovenous thermal ablations (ETAs) are recommended as first-line treatment for truncal vein reflux, have a short recovery time, and are cost-effective. However, ETAs are associated with discomfort during tumescent anesthesia infiltration. To minimize discomfort, nonthermal, nontumescent ablation techniques had emerged in the form of mechanochemical ablation (MOCA) and cyanoacrylate adhesive injection (CAE).

Objective

To assess pain scores immediately after truncal ablation using a 100-mm visual analog scale and 10-point number scale to compare pain-related outcomes following mechanochemical ablation vs cyanoacrylate adhesive treatment.

Design, Setting, and Participants

The Multicenter Randomized II Clinical Trial Comparing Mechanochemical Ablation vs Cyanoacrylate Adhesive for the Treatment of Primary Truncal Saphenous Veins Incompetence study was a prospective multicenter randomized clinical trial conducted at 3 sites between November 2017 and January 2020. Inclusion criteria were primary great or small saphenous varicose veins; exclusion criteria included recurrent varicose veins, current deep venous thrombosis, or serious arterial disease. There were 392 participants screened, 225 were excluded, and 167 participants underwent randomization. Four participants did not receive allocated intervention and were included in the intention-to-treat analysis. Follow-up took place at 2 weeks, and 3, 6, and 12 months.

Interventions

Patients with primary truncal vein incompetence were randomized to receive either MOCA or CAE.

Main Outcomes and Measures

The primary outcome measure was pain score immediately after completing truncal ablation using a 100-mm visual analog scale (VAS) and a 10-point number scale. Secondary outcome measures included degree of ecchymosis, occlusion rates, clinical severity, and generic and disease-specific quality of life (QoL) scores.

Results

Of 167 study participants, 99 (59.3%) were women, and the mean (SD) age was 56 (15.8) years. Overall, 155 truncal veins treated (92.8%) were great saphenous veins. Demographic data and baseline status were comparable between treatment groups. A total of 73 patients (47%) underwent adjunctive treatment of varicosities. Overall median (IQR) maximum pain score after truncal treatment was 23 mm (10-44) on the VAS and 3 (2-5) on the number scale, showing no significant difference in median (IQR) pain measured by VAS (MOCA, 24 [11.5-44.7] mm vs CAE, 20 [9.0-42.0] mm; P = .23) or by number scale (MOCA, 4 [2-5] vs CAE, 3 [2-4]; P = .18). Both groups demonstrated significant and comparable improvement in clinical severity, generic and disease-specific QoL scores, and complete occlusion rates. Four patients treated with CAE developed minor complications (superficial thrombophlebitis and thrombus extensions).

Conclusions and Relevance

To our knowledge, this was the first randomized clinical trial directly comparing nontumescent ablation techniques. The study demonstrated that the MOCA and CAE techniques have a similar periprocedural pain score.

Trial Registration

ClinicalTrials.gov Identifier: NCT03392753.

Treatment of a Delayed Type IIIb Endoleak 20 Years Post EVAR With Inverted Contralateral Limb Custom-Made Device: A Case Report

PURPOSE

Type III endoleak can be difficult to distinguish from Type I endoleak. Depending on the stent graft anatomy, the use of standard bifurcated endografts may not be technically feasible, and patients may have to be subject to an aorto-uni-iliac repair with femoral-femoral bypass or open surgery.

CASE REPORT

We report a case of an 86-year-old male who had a Type IIIb endoleak 20 years post EVAR which was characterized on angiography to be from a hole close to the bifurcation limb origin. The initial Talent (Medtronic, Santa Rosa, California) device had a 50 mm main body common trunk, which was not amenable to treatment with standard devices. He was successfully treated with a custom-made device with an inverted contralateral limb.

CONCLUSIONS

Our case highlights the need for lifelong surveillance post EVAR as endoleak may present decades post initial EVAR. It also demonstrates that many Type III endoleak which were otherwise deemed unsuitable for treatment with standard devices may potentially be treatable with custom-made device (CMD). This solution preserves a percutaneous option in a now older person which avoids surgical bypass. Further studies are required to establish the durability of this treatment and survey for recurrence.

Diabetes and other vascular risk factors in association with the risk of lower extremity amputation in chronic limb-threatening ischemia: a prospective cohort study

BACKGROUND

Patients with diabetes are at increased risk of developing chronic limb-threatening ischemia (CLTI) due to peripheral arterial disease, and this often results in lower extremity amputation (LEA). Little is known of the interaction between diabetes and other vascular risk factors in affecting the risk of CLTI.

METHODS

We investigated the association of diabetes, and its interaction with hypertension, body mass index (BMI) and smoking, with the risk of LEA due to CLTI in the population-based Singapore Chinese Health Study. Participants were interviewed at recruitment (1993-1998) and 656 incident LEA cases were identified via linkage with nationwide hospital database through 2017. Multivariate-adjusted Cox proportional hazards models were used to compute hazard ratios (HRs) and 95% CIs for the associations.

RESULTS

The HR (95% CI) for LEA risk was 13.41 (11.38-15.79) in participants with diabetes compared to their counterparts without diabetes, and the risk increased in a stepwise manner with duration of diabetes (P for trend < 0.0001). Hypertension and increased BMI independently increased LEA risk in those without diabetes but did not increase the risk in those with diabetes (P for interaction with diabetes ≤ 0.0006). Conversely, current smoking conferred a risk increment of about 40% regardless of diabetes status.

CONCLUSIONS

Although diabetes conferred more than tenfold increase in risk of LEA, hypertension and increased BMI did not further increase LEA risk among those with diabetes, suggesting a common mechanistic pathway for these risk factors. In contrast, smoking may act via an alternative pathway and thus confer additional risk regardless of diabetes status.

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.govNCT04409912. Registered on 1 June 2020

MagicTouch PTA Sirolimus Coated Balloon for Femoropopliteal and Below the Knee Disease: Results From XTOSI Pilot Study Up To 12 Months

INTRODUCTION

Sirolimus coated balloon (SCB) is a promising treatment option to prevent restenosis for peripheral arterial occlusive disease (PAOD). This is a pilot first-in-human study of MagicTouch percutaneous transluminal angioplasty (PTA) SCB for treatment of PAOD for both femoropopliteal and below the knee arteries (BTK).

MATERIAL AND METHODS

Xtreme Touch-Neo [MagicTouch PTA] Sirolimus Coated Balloon (XTOSI) pilot study is a prospective, single-arm, open-label, single-center trial evaluating MagicTouch PTA SCB for symptomatic PAOD. Primary endpoint was defined as primary patency at 6 months (duplex ultrasound peak systolic velocity ratio ≤2.4). Secondary endpoints included clinically driven target lesion revascularization (CD-TLR), amputation free survival (AFS), all-cause mortality, and limb salvage success.

RESULTS

Fifty patients were recruited. The mean age was 67 (n=31 [62%] males). SCB was applied to femoropopliteal in 20 patients (40%) and BTK in 30 patients (60%). Majority of treatments (94%) were performed for limb salvage indications (Rutherford scores 5 or 6). This was a high risk cohort, in which 90% had diabetes, 36% had coronary artery disease, 20% had end stage renal failure, and American Society of Anaesthesiologists (ASA) score was 3 or more in 80%. Mean lesion length treated was 227±81 mm, of which 36% were total occlusions. Technical and device success were both 100%. At 30 days, mortality was 2% and major limb amputation was also 2%. Six-month primary patency was 80% (88.2% for femoropopliteal; 74% for BTK). At 12 months, freedom from CD-TLR was 89.7% (94.1% for femoropopliteal; 86.3% for BTK), AFS was 81.6% (90.0% for femoropopliteal; 75.9% for BTK), all-cause mortality was 14.3% (10.0% for femoropopliteal; 17.2% for BTK), and limb salvage success was 92.9% (94.4% for femoropopliteal; 91.7% for BTK). There was a statistically significant increase between baseline and 6-month toe pressures for both femoropopliteal (57.3±23.3 mm Hg vs 82.5±37.8 mm Hg; p<.001) and BTK lesions (52.8±19.2 mm Hg vs 70.7±37 mm Hg; p<.037). At 12 months, wound healing rate was 33/39 (84.6%).

CONCLUSIONS

MagicTouch PTA SCB in the XTOSI study showed promising 6-month primary patency and encouraging 12-month freedom from CD-TLR, AFS, and limb salvage rates. No early safety concerns were raised. Randomized trials are needed to investigate the safety and efficacy of SCB for treatment of PAOD.

Health Services Use and Functional Recovery Following Blunt Trauma in Older Persons - A National Multicentre Prospective Cohort Study

OBJECTIVE

Frailty is associated with morbidity and mortality in older injured patients. However, for older blunt-trauma patients, increased frailty may not manifest in longer length of stay at index admission. We hypothesized that owing to time spent in hospital from readmissions, frailty would be associated with less total time at home in the 1-year postinjury period.

DESIGN

Prospective, nationwide, multicenter cohort study.

SETTING AND PARTICIPANTS

All Singaporean residents aged ≥55 years admitted for blunt trauma with an Injury Severity Score (ISS) or New Injury Severity Score (NISS) ≥10 from March 2016 to July 2018.

METHODS

Frailty (by modified Fried criteria) was assessed at index admission, based on questions on preinjury weight loss, slowness, exhaustion, physical activity, and grip strength at the time of recruitment. Low time at home was defined as >14 hospitalized days within 1 year postinjury. The contribution of planned and unplanned readmission to time at home postinjury was explored. Functional trajectory (by Barthel Index) over 1 year was compared by frailty.

RESULTS

Of the 218 patients recruited, 125 (57.3%) were male, median age was 72 years, and 48 (22.0%) were frail. On univariate analysis, frailty [relative to nonfrail: odds ratio (OR) 3.45, 95% confidence interval (CI) 1.33-8.97, P = .01] was associated with low time at home. On multivariable analysis, after inclusion of age, gender, ISS, intensive care unit admission, and surgery at index admission, frailty (OR 5.21, 95% CI 1.77-15.34, P < .01) remained significantly associated with low time at home in the 1-year postinjury period. Unplanned readmissions were the main reason for frail participants having low time at home. Frail participants had poorer function in the 1-year postinjury period.

CONCLUSIONS AND IMPLICATIONS

In the year following blunt trauma, frail older patients experience lower time at home compared to patients who were not frail at baseline. Screening for frailty should be considered in all older blunt-trauma patients, with a view to being prioritized for postdischarge support.

Endoleak Complicated by communicating psoas abscess and aorto-enteric fistula in an immunocompromised patient

PURPOSE

While endovascular repair of aortic aneurysm (EVAR) has become the mainstay treatment for abdominal aortic aneurysm (AAA), it is not without its disadvantages. Feared complications include graft infections, fistulation and endoleak, the outcomes of which may be life limiting.

CASE REPORT

We present a case of a 57 year-old patient with human immunodeficiency virus (HIV) previously treated with EVAR for AAA complicated by endoleak post treatment. He developed an aorto-psoas abscess 2 years later which harboured Mycobacterium avium complex, and medical therapy was unsuccessful. He eventually underwent an extra-anatomical bypass and graft explant, for which an aortoenteric fistula was also discovered and repaired.

CONCLUSION

Infection of endografts post EVAR is relatively rare, and there are presently no guidelines concerning its management. The concomittance of aorto-psoas abscess and aortoenteric fistula is even more uncommon, and necessitated surgical explant for source control purposes in our patient. Lifelong surveillance is required for complications of the aortic stump and bypass patency.

Registry to investigate the efficacy and safety of the VenaBlock© VeIn SEaling system for VaRicose veins in SingApore - Six months results of the RIVIERA trial

BACKGROUND

The Venablock^© Venous Closure System (Invamed, Ankara, Turkey) is a novel cyanoacrylate-based non-thermal non-tumescent embolization device to block refluxing truncal veins for chronic venous insufficiency and varicose veins. The aim was to prospectively evaluate the safety and 6 months efficacy of Venablock^© for the treatment of primary great saphenous vein (GSV) and small saphenous vein (SSV) incompetency in a multi-ethnic cohort from Singapore.

METHODS

This was a single arm, single investigator prospective study of 29 patients (39 limbs, 39 truncal veins) recruited over a 5-month period (August 2019 to February 2020), who were treated with the Venablock^© device at a tertiary vascular unit in Singapore. Patients with symptomatic varicose veins (C2-6) and had truncal reflux > 0.5 second on venous Duplex ultrasound were included. Follow-up occurred at 2 weeks, 3 and 6 months with dedicated quality of life questionnaires and a targeted Duplex ultrasound performed to check for continued venous occlusion.

RESULT

Mean age was 61.4 (±11.0) years and mean BMI was 26.2 (±5.7) kg/m². 11/29 (37.9%) were males. Most common CEAP class treated was 2 (12/29, 41.3%). Mean diameter of treated GSV was 5.7 (±2.0) mm, 4.8 (±1.7) mm and 4.2 (±1.3) mm for the proximal, mid and distal above knee segments respectively. Mean time from access puncture to sheath removal was 23.4 (±10.0) mins. Vein occlusion at 2 weeks, 3 and 6 months was 39/39 (100%), 39/39 (100%) and 36/37 (97.2%) respectively. 5/29 (17.2%) developed puncture site infections, of which 3/29 (7.7%) required formal surgical drainage. 3/29 (7.7%) developed phlebitis. At 6 months, revised Venous Clinical Severity Score improved from 5.2 (±3.5) to 2.1 (±2.9; p < .001); EuroQol-5 Dimension score, from 7.4 (±2.1) to 5.7 (±1.4; p < .001); Aberdeen Varicose Vein Questionnaire score, from 18.1 (±15.5) to 7.9 (±8.9; p = .007); and Chronic Venous Insufficiency Questionnaire, from 18.6 (±16.2) to 4.5 (±6.3; p < .001).

CONCLUSION

Venablock^© is a safe and efficacious option of treating truncal venous insufficiency in a multi-ethnic Asian cohort from Singapore in the short term. There is a significant improvement in QoL. Longer follow-up is required to assess the durability of this technique, in particular the higher puncture site infection rates observed compared to other glue-based therapies.

Evidence-based medical treatment of peripheral arterial disease: A rapid review

ABSTRACT Introduction: Peripheral arterial disease (PAD) treatment guidelines recommend the use of statins and antiplatelets in all PAD patients to reduce adverse cardiovascular and limb-related outcomes. In addition, hypertension and diabetes should be treated to reach recommended targets. The aim of this rapid review was to evaluate the level of adherence to evidence-based medical therapy (EBMT) recommended by PAD treatment guidelines in the real-world setting. Methods: We searched PubMed and Embase using keywords, MeSH and Emtree terms related to the population, exposure and outcomes from their inception to 22 September 2020. We included randomised controlled trials, non-randomised studies, and observational studies reporting adherence to at least 1 of these 4 drug classes: (1) statins, (2) antiplatelets, (3) antihypertensives and (4) antidiabetic drugs. Non-English articles, abstracts, dissertations, animal studies and case reports or series were excluded. A narrative summary of the results was performed. Results: A total of 42 articles were included in the review. The adherence to lipid-lowering drugs/statins ranged from 23.5 to 92.0% and antiplatelets from 27.5 to 96.3%. Only 7 and 5 studies reported use of “any anti-hypertensive” and “any anti-diabetic” medications, respectively, and the proportion of the cohort treated were generally close to the proportion with hypertension and/or diabetes. Adherence in studies published in 2016–2020 ranged from 52.4–89.6% for lipid-lowering drugs and 66.2–96.3% for antiplatelets. Conclusion: EBMT adherence in PAD patients was highly variable and a substantial proportion in many settings were undertreated. There was also a notable lack of studies in Asian populations. Keywords: Evidence-practice gap, medication adherence, pharmacoepidemiology

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.

Endovenous cyanoacrylate ablation for chronic venous insufficiency and varicose veins among Asians

Introduction: Endovenous cyanoacrylate glue (CAG) ablation for the treatment of chronic venous insufficiency (CVI) and varicose veins has shown non-inferior outcomes with an excellent safety profile, high patient satisfaction rate, and excellent efficacy when compared to the gold standard of endothermal ablation. A review of the current literature for CAG use in CVI showed that most studies and longer-term data are from Caucasian-based populations, which are subject to different anatomical venous variations and socio-economical contexts. This review aimed to gather the current evidence for CAG use in Asian CVI patients. Methods: Asian studies for the use of CAG in CVI were included in this review. Successful ablation rates, quality of life improvement and novel complications such as glue hypersensitivity reactions are described, along with anatomical descriptions of superficial venous anatomy in study patients. Use of CAG in Singapore and Asia was addressed. Results: CAG has been gaining traction as an option for CVI treatment in Asians. In Singapore, it has been adopted with comparable low complication rates and significant improvement of quality of life after treatment. As we increase our understanding of the variations in venous anatomy in the Asian population, new techniques such as retrograde deployment of the device and use of CAG ablation for venous leg ulcers have been developed. Conclusion: Further robust evidence in terms of large randomised control trials along with costeffectiveness studies are needed to determine the true value of CAG ablation in the Asian setting.

Computed tomography venography versus intravascular ultrasound in the diagnosis of iliofemoral vein stenosis

Summary: Background: Iliofemoral vein stenosis can cause debilitating chronic venous disease. Diagnostic tools include both computed tomography venography (CTV) and intravascular ultrasonography (IVUS). We aim to compare the diagnostic performance of CTV and IVUS. Patients and methods: We performed a retrospective study of patients with chronic venous disease presenting with iliac vein compression or post-thrombotic limb symptoms, excluding those with acute deep vein thrombosis, high anaesthesia risk, or who had contrast allergy. All patients received CTV before IVUS, as part of the diagnostic work-up and intervention. The cross-sectional area (CSA) of iliofemoral vein segments obtained from both studies were compared against reference CSAs to derive percentage stenosis. A 50% reduction in CSA was considered significant. Results: We studied 50 patients between May 2018 and April 2019. 58% of patients had severe disease CEAP C5-6. 48% of patients had at least one vein segment with significant stenosis. The left proximal common iliac vein was the most commonly stenosed vein segment (n = 12, 24% on IVUS). CSA measurements from CTV were greater than those of IVUS, with a correlation coefficient of 0.57 (p < 0.005). Conversely, percentage stenosis measured on CTV was lower than on IVUS, with approximately one-third of significant stenosis missed on CTV (58 veins from CTV vs. 78 from IVUS, p < 0.005). With IVUS as the gold standard, CTV has low sensitivity (37.2%, 95% CI 26.5–48.9) and high specificity (92.5%, 95% CI 89.3–94.9) in detecting significant stenosis. Conclusions: CTV has limited diagnostic performance in identifying iliofemoral vein stenosis. Patients with normal CTV findings should proceed with IVUS imaging if the clinical features are supportive of iliofemoral vein stenosis.

Single Asian Center Experience Using the Flixene™ Early Cannulation Graft for Hemodialysis Access Creation

BACKGROUND

The aim of this study was to review the efficacy of the Flixene™ (Atrium™, Hudson, NH, USA) hemodialysis arterio-venous graft (AVG) in a multiethnic Asian cohort of patients with end-stage renal failure (ESRF). Primary outcome was graft primary patency rate and secondary end points included graft usability, time to cannulation, reinterventions required for access salvage, complications, and patient mortality.

METHODS

Single-center, single-arm, multi-investigator nonrandomized retrospective study. Patients with ESRF who underwent Flixene™ graft implantation over a two-year period (January 2017 - December 2018) were included to allow at least one-year follow-up. Demographics, procedural and follow-up data were collected from the hospital electronic medical records.

RESULTS

About 48 patients (49 AVG) were included. There were 24 (50%) men; mean age 63.7 (IQR 58.2-71.3) years. Technical success rate was 45/49 (91.8%); 4/49 (8.2%) AVG created did not reach cannulation. 11/49 (22.4%) and 28/49 (57.1%) achieved cannulation within 1 and 2 weeks, respectively. 6- and 12- month primary patencies were 33.5% and 19.6%, respectively. Primary-assisted patency rates were 46.6% and 29.6% at the same time intervals. Secondary patency rate was 77.6% and 63.9% at 6 and 12 months, respectively. There were 6 (12.2%) graft infections requiring explant and one-year mortality was 14%.

CONCLUSIONS

Our experience with the Flixene™ early cannulation graft is comparable with other AVGs in terms of patency and infection rates. However, early cannulation rates are lower than in other case series.

The Cleaner XT™ Device as an Endovascular Adjunct for Pharmacomechanical Thrombolysis of Thrombosed Arteriovenous Fistulas and Grafts

Objective: This paper documents our experience using the Cleaner XT™ device (Argon Medical Devices, Plano, TX, USA) for pharmacomechanical thrombolysis (PMT) of thrombosed haemodialysis arteriovenous grafts (AVG) and fistulas (AVF). Materials and Methods: This was a retrospective case series (n=17) over six months at Singapore General Hospital. We evaluated demographics, procedural data, technical and procedural success, patency rates and complications. Results: There were 8 (47%) males and the patients' mean age was 66 (± 5.7) years. The mean age of AVF/AVG was 1605 (± 1099) days. All procedures were performed under local anaesthetic. PMT was performed within a mean time of 40 (±34.3) hours from the presentation. Technical, clinical and procedural success was 15/17 (88%). The thrombolysis agents used were tissue plasminogen activator (52.9%) and urokinase (41.2%). Mean primary patency time was 114 (± 116) days, with a 65% 1-month and 47% 3-month primary patency rates. The mean secondary patency time was 155 (±132) days, with 76% one-month and 65% three-month secondary patency rates, respectively. AVF rupture occurred in 3/17 (18%) cases but did not involve loss of the access circuit. Conclusion: The Cleaner XT™ device is a safe, minimally invasive endovascular tool for PMT in thrombosed AVF/AVG, with relatively high success and low complication rates.

Single-Center Prospective Pilot Study of Sirolimus Drug-Coated Balloon Angioplasty in Maintaining the Patency of Thrombosed Arteriovenous Graft

PURPOSE

To investigate the use of a sirolimus drug-coated balloon (DCB) in the management of a thrombosed arteriovenous graft (AVG).

MATERIALS AND METHODS

A single-center prospective pilot study was conducted between October 2018 and October 2019. Twenty patients (age = 67.0 years ± 10; male = 35%; mean time on dialysis = 31 months) with thrombosed upper limb AVG were enrolled. After successful pharmacomechanical thrombectomy and adequate treatment of the graft vein junction, sirolimus DCB angioplasty was performed at the graft vein junction. The patients were followed-up for 6 months, and all adverse events occurring during the study period were recorded.

RESULTS

The primary circuit patency rates at 3 and 6 months were 76% and 65%, respectively, while the assisted-primary circuit patency rates at 3 and 6 months were 82% and 65%, respectively. The 3- and 6-month secondary circuit patency rates were 88% and 76%, respectively. Using Kaplan-Meier analyses, the estimated mean primary, assisted-primary, and secondary patencies were 285 days (95% confidence interval (CI) = 194-376 days), 319 days (95% CI = 221-416 days), and 409 days (95% CI = 333-485 days). No adverse event directly related to sirolimus DCB use was observed.

CONCLUSIONS

The results of this pilot study suggest that the application of sirolimus DCB at the graft vein junction after the successful thrombectomy of AVG may be a feasible option to improve patency outcomes.

Effect of short-term low molecular weight heparin on patency following successful salvage of arteriovenous access with recurrent thrombosis

AIM

This study aims to investigate the effect of low molecular weight heparin (LMWH) in maintaining the patency of arteriovenous (AV) access with recurrent thrombosis.

METHODS

Following successful thrombectomy, 66 patients with recurrent thrombosis were included in the study. The primary, assisted primary and secondary patency rates of patients who received LMWH (n = 24) were compared with those who did not receive anticoagulant (n = 42) using Kaplan-Meier analysis. Cox-regression analysis was performed to investigate potential predictors of patency rates.

RESULTS

The mean dose of enoxaparin used was 40 ± 13.1 mg or 0.74 ± 0.2 mg/kg daily for a median duration of 14 (IQR 7,28) days. The mean trough anti-Xa concentrations measured after two doses of LMWH was 0.17 ± 0.13 IU/mL. Kaplan-Meier analyses for mean primary, assisted primary and secondary patency rates of LMWH vs no anticoagulation groups were 149 (95% CI: 91 - 207) vs 87 (95% CI: 42-132) days (P < .006), 230 (95% CI: 142-320) vs 107 (95% CI: 62-150) days (P = .01) and 438 (299-579) vs 294 (95% CI: 197-392) days (P = .08) respectively. LMWH remained a significant protective predictor of primary (HR: 0.49; 95% CI: 0.25-0.86; P = .02) and assisted primary patency rates (HR: 0.51; 95% CI: 0.27-0.98; P = .04) after adjusting for patient age, access age, type of AV access, presence of peripheral vascular disease and haemoglobin levels.

CONCLUSION

LMWH may improve short and mid-term patency rates for AV accesses with recurrent thrombosis.

"Angioplasty-First" Approach for Limb Salvage in Asian Patients with Critical Limb Ischemia: Outcomes from 3,303 Angioplasties on 2,402 Limbs in a Single Tertiary Hospital

PURPOSE

To review outcomes of patients with critical limb ischemia (CLI) who underwent conventional percutaneous transluminal angioplasty (PTA) as first-line treatment for revascularization.

MATERIALS AND METHODS

Retrospective review of 3,303 angioplasty procedures on 2,402 limbs in 1,968 patients with CLI was conducted. Mean patient age was 68 years ± 11, and 1,057 patients (54%) were male. Diabetes mellitus (DM) was present in 1,736 patients (88%), and end-stage renal disease (ESRD) in 579 (29%). A majority of patients (90%) had tissue loss. Limb salvage rates were generated by Kaplan-Meier plot. Univariate and multivariate Cox regression analysis was conducted to investigate associations between clinical predictors and time-to-event outcome.

RESULTS

Limb salvage rates at 1, 3, 5, and 10 years were 75%, 73%, 72%, and 62%, respectively, and overall survival rates were 79%, 64%, 56%, and 34%, respectively. In multivariable Cox regression analysis with the outcome of major amputation, significant predictors included age < 69 years (P = .032), Malay race (P = .029), DM (P < .001), history of cerebral vascular disease (P = .003), ESRD (P < .001), Rutherford classification (P = .042), repeat intervention (P = .034), and number of straight-line flows (P < .001) and plantar arch integrity (P < .001) on completion angiography. Significant associations with mortality were age < 69 years (P < .001), male sex (P = .030), Malay race (P = .027), history of ischemic heart disease (P < .001), ESRD (P < .001), and repeat intervention (P < .001).

CONCLUSIONS

PTA as first-line revascularization for patients with CLI is safe and effective. Further studies are suggested to validate the outcome predictive model.

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.

Heal or no heel: Outcomes of ischaemic heel ulcers following lower limb revascularization from a multi-ethnic Asian Cohort in Singapore

Ischaemic diabetic heel ulcers are difficult to treat and prognosis is often guarded. The aim was to document our outcome of treating heel ulcers following revascularization in a predominantly diabetic Asian cohort presenting with chronic limb threatening ischaemia from Singapore. Retrospective cohort study (n = 66, 66 limbs) over a 5‐year period. Data were collected from hospital electronic health records. Outcomes included time to healing, amputation free survival (AFS), and mortality. Minimum follow‐up period was 6 months. Multivariate regression analysis was performed to look for factors associated with poor outcome. Mean age was 67.4 ± 8.8 years. 62/66 (93.9%) were diabetics. Mean wound size at presentation was 3.6 ± 2.3 cm. Mean Wound, Ischaemia, Foot Infection (WIFI) score was 5 ± 1.6. 12/66 (18%) patients had a patent posterior tibial artery pre‐operatively. Straight line flow was restored in only 31/66 (46.9) patients but 47/66 (71.2%) had successful limb salvage. Median time to wound healing was 90.0 (IQR 60‐180) days. A median of 1 (IQR 0‐2) wound debridement was required. Patients who underwent negative pressure dressing (23/66; 34.8%) required a median of 26 (IQR 13‐33) cycles to achieve healing. Amputation free survival (AFS) was 72% and 68% at 6‐ and 12‐months, respectively. Mortality rate was 16.7% and 19.7% at 6‐ and 12‐months, respectively. Low albumin level and initial Rutherford class were independent predictors of worse 6‐month AFS. Outcomes of heel ulcers post revascularisation may not be as poor as previously described. Persistent attention to wound care with multidisciplinary effort is needed for optimal healing.

Endovascular Deep Vein Stenting of Symptomatic Post-Thrombotic and Non-Thrombotic Iliac Vein Stenotic Lesions: A Multicentre Cohort Experience from Singapore

INTRODUCTION

This paper presents our experience with deep venous stenting in a multi-ethnic Asian cohort of patients with symptomatic Non-Thrombotic Iliac Vein Lesions (NIVL) and Post-Thrombotic Syndrome (PTS).

MATERIALS AND METHODS

This was a multicentre retrospective cohort study of patients who had symptomatic deep venous disease. Stent patency rate was evaluated using Duplex ultrasonography immediately post-intervention and at 3, 6 and 12 months. Clinical outcomes were evaluated using the revised Venous Clinical Severity Score (rVCSS) and Visual Analogue Scale (VAS) pain score at baseline and 3 months post-procedure.

RESULTS

87 patients (males = 47/87 (54.0%)); median age = 62 years (IQR 55 - 70)) and 115 limbs were analysed (left = 76/115 (66.1%)). Median follow-up time was 175 (IQR 57 - 257) days. 97/115 (84.3%) had NIVLs and 55/115 (47.8%) had May-Thurner-Syndrome. 43/115 (37.4%) had Clinical, Etiology, Anatomy and Pathophysiology (CEAP) 6 disease. Primary stent patency rates were 98.2% (112/114), 97.9% (93/95), 95.7% (89/93) and 92.8% (64/69) immediately post-intervention, 3, 6 and 12 months, respectively. The 6-month secondary patency rate was 99.1% (114/115). Mean rVCSS and VAS improved from 11.52 (±3.54) to 5.77 (±2.36) (P < 0.01) and 6.62 (±1.93) to 2.92 (±1.50) (P < 0.01) respectively, at 3 months. 41/43 (95.3%) venous ulcers healed over a median time of 169 days (IQR 120 - 253).

CONCLUSIONS

Short term primary patency rates following deep venous stenting are excellent, with few re-interventions. Patients presented with NIVLs rather than PTS. There was excellent clinical improvement at 3 months, with a high and expedient venous ulcer healing rate.

Utility of a novel high pressure non-compliant balloon for tibial atherosclerotic lesions in Asian patients with chronic limb threatening ischaemia

Background: The aim was to evaluate the safety and efficacy of a high pressure, non-compliant balloon in the treatment of infrapopliteal occlusive disease in Asian patients with chronic limb threatening ischaemia (CLTI) from Singapore. Patients and methods: Prospective, multi-centre, single arm, non-randomized study. Immediate technical success, 6-month primary vessel patency (determined by Duplex ultrasonography), limb salvage, one-year clinically driven target lesion re-intervention (TLR) and amputation free survival (AFS) were the efficacy endpoints of interest. Results: 86 patients (63% males, mean age 68.9 ± 9.9 years) were enrolled over a 15-month period. Diabetes mellitus (DM) and end-stage renal failure (ESRF) were present in 94% and 38% of patients respectively. All had some degree of tissue loss at baseline (Rutherford scale 5 and 6 = 91% and 9% respectively). Of the 86 legs, 72% had 3 crural vessel disease and 84% had moderate/severe vessel wall calcification. 90% had > = 1 TASC D tibial lesion. Acute technical success was 89%. One month mortality was 3.5% and one-year freedom from TLR was 91%. 6-month tibial patency was 73%. 54/66 (82%) patients had at least one target treated tibial artery open at 6 months. A lower baseline toe pressure (OR 1.03, 95%CI 1.00-1.05) and elastic recoil post angioplasty (OR 0.20, 95%CI 0.05-0.79) were associated with a worse 6 month tibial patency. One-year AFS was 67%. 47/66 (71%) patients had a clinical improvement of at least one Rutherford class at 6 months and 52/59 (88%) experienced complete wound healing at 12 months. Conclusions: Use of a high pressure non-compliant balloon is safe and efficacious in treating highly complex infra-popliteal atherosclerotic lesions in an otherwise challenging population of CLTI patients with a high incidence of DM and ESRF. It is associated with highly satisfactory acute technical success, 6-month target lesion patency and one-year limb salvage.

Two-year clinical outcomes following lower limb endovascular revascularisation for chronic limb threatening ischaemia at a tertiary Asian vascular centre in Singapore

INTRODUCTION

Percutaneous transluminal angioplasty (PTA) is commonly used to treat patients with chronic limb-threatening ischaemia (CLTI). This study aimed to examine mortality and functional outcomes in a multi-ethnic Asian population from Singapore of CLTI patients who predominantly had diabetes mellitus.

METHODS

CLTI patients who underwent PTA between January 2015 and March 2017 at the Vascular Unit at Singapore General Hospital, Singapore, were studied. Primary outcome measures were 30-day unplanned readmission, two-year major lower extremity amputation (LEA), mortality rates, and ambulation status at one, six and 12 months.

RESULTS

221 procedures were performed on 207 patients, of whom 184 (88.9%) were diabetics. One-, six- and 12-month mortality was 7.7%, 16.4% and 21.7%, respectively. The two-year LEA rate was 30.0%. At six and 12 months, only 96 (46.4%) and 93 (44.9%) patients were ambulant, respectively. Multivariate analysis revealed that preoperative ambulatory status; haemoglobin; Wound Ischaemia and foot Infection (WIfI) score; and end-stage renal failure (ESRF) were independent predictors for one-year ambulatory status. Predictors of mortality at one, six and 12 months were ESRF, preoperative albumin level, impaired functional status and employment status.

CONCLUSION

PTA for CLTI was associated with low one-year mortality and two-year LEA rates but did not significantly improve ambulation status. ESRF and hypoalbuminemia were independent predictors of mortality. ESRF/CKD and WIfI score were independent predictors of loss of ambulation at six months and one year. We need to better risk stratify CLTI patients to decide between initial revascularisation and an immediate LEA policy.

Study protocol of a pilot study on sirolimus-coated balloon angioplasty in salvaging clotted arteriovenous graft

Background

In arteriovenous graft (AVG) for haemodialysis, the primary cause of failure is venous stenosis of the graft-vein junction from neointimal hyperplasia (NIH), resulting in thrombosis. While interventions to salvage clotted AVG are known to have high clinical success rates, long-term patency rates have been suboptimal. Drug-coated balloon (DCB) has been used to treat stenosed arteriovenous access in recent years with encouraging results but data on its effect in clotted AVG is unavailable.

Methods

This is an investigator-initiated, single-center, single-arm prospective pilot study to determine the safety and outcome of the sirolimus-coated balloon (SCB) in the salvage of thrombosed AVG. Twenty patients who undergo successful percutaneous thrombectomy will receive treatment with SCB at the graft vein junction. The patients will be followed-up for 6-months. The primary endpoint is the patency rates at 3-month while the secondary endpoints are the patency rates and the number of interventions needed to maintain patency at 6-month.

Discussion

Unremitting efforts have been made to prolong the patency of AV accesses over the years. DCB angioplasty combines mechanical and biological treatment for vascular stenosis. Sirolimus, being a cystostatic anti-proliferative agent, has been successfully used in coronary artery interventions. As the primary pathology of vascular stenosis in the dialysis circuit is neointimal hyperplasia, the use of sirolimus in balloon angioplasty may be effective. With this prospective study, we evaluate the efficacy and safety of SCB in patients with clotted AVG.

Trial registration

ClinicalTrials.gov Identifier: NCT03666208 on 11 September 2018.

The Modified Frailty Index Does Not Predict Mortality After Major Lower Extremity Amputation for Peripheral Arterial Disease in an Asian Population

BACKGROUND

Patients with critical limb ischemia (CLI) who undergo major lower extremity amputation (LEA) have been associated with high one-year mortality rates. Previous western-based studies have identified risk factors that exponentiate these poor outcomes, including nonambulatory status and cardiovascular morbidity. We assessed the effect of frailty, using the modified frailty index (mFI) in a cohort undergoing major LEA for CLI to predict mortality, perioperative complications, and unplanned readmissions in a tertiary institution from Singapore.

METHODS

Data on patients who had undergone major LEA from January 2016 to December 2017 were collected retrospectively. Inclusion criteria were below-knee amputations (BKAs) or above-knee amputations (AKAs) performed for peripheral arterial disease-related tissue loss or sepsis only. Patients were categorized into 3 risk groups based on the 11-variable mFI: low mFI, 0-0.27; moderate mFI, 0.36-0.54; and high mFI ≥0.63. Univariate and multivariate analysis was performed using logistic regression analysis.

RESULTS

211 patients underwent major LEA, of whom 133 (63.0%) had undergone BKA. The mean mFI was 0.41 (range 0-0.81). 84/211 (39.8%) died within 1 year after the procedure, with mortality rates of 25/65 (38.4%), 49/127 (38.6%), and 10/19 (52.6%) in the low-, moderate-, high-mFI categories, respectively. High and moderate mFI had failed to demonstrate an increased risk of mortality when compared with the low-mFI group (P > 0.05). 91/211 (43.1%) patients had perioperative complications, whereas 27/211 (12.8%) patients were readmitted within 30 days of discharge. Myocardial infarction, chronic kidney disease, and atrial fibrillation were found to be predictive of poor outcomes after major LEA.

CONCLUSIONS

Frailty as measured with the mFI did not predict outcome after major LEA. This could be due to confounding effects such as high prevalence of renal dysfunction and the constancy of diabetes and peripheral vascular disease in this population that would reduce the differentiation of patients using the mFI.