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

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).

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.

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.

Update on the pathophysiology and medical treatment of peripheral artery disease

Approximately 6% of adults worldwide have atherosclerosis and thrombosis of the lower limb arteries (peripheral artery disease (PAD)) and the prevalence is rising. PAD causes leg pain, impaired health-related quality of life, immobility, tissue loss and a high risk of major adverse events, including myocardial infarction, stroke, revascularization, amputation and death. In this Review, I describe the pathophysiology, presentation, outcome, preclinical research and medical management of PAD. Established treatments for PAD include antithrombotic drugs, such as aspirin and clopidogrel, and medications to treat dyslipidaemia, hypertension and diabetes mellitus. Randomized controlled trials have demonstrated that these treatments reduce the risk of major adverse events. The drug cilostazol, exercise therapy and revascularization are the current treatment options for the limb symptoms of PAD, but each has limitations. Novel therapies to promote collateral and new capillary growth and treat PAD-related myopathy are under investigation. Methods to improve the implementation of evidence-based medical management, novel drug therapies and rehabilitation programmes for PAD-related pain, functional impairment and ischaemic foot disease are important areas for future research.

Physician initiated, prospective, non-randomized Multi-center trial, Investigating the safety and Efficacy of the TReatment with the LuminorTM Drug Coated Balloon and the AngioliteTM Drug Eluting Stent of IVascular in TASC C and D Tibial Occlusive disease iN patients with critical limb ischemia: 12-month results

BACKGROUND

The aim of MERLION (NCT04073121) was to evaluate the outcomes of the mono or combination therapy of the iVascular LuminorTM drug coated balloon (DCB) and AngioliteTM drug eluting stent for treatment of TASC II C/D tibial occlusive lesions in Asian patients presenting with chronic limb threatening ischemia (CLTI) from Singapore.

METHODS

MERLION was a prospective, non-randomized, single arm, observational, multicenter clinical study. Complication-free survival at one month was the safety endpoint. Immediate technical success, 12-month primary vessel patency, limb salvage, freedom from target lesion revascularization (TLR) and amputation free survival (AFS) were the efficacy endpoints of interest.

RESULTS

50 patients were included. There were 32 males (64% males; mean age 66.4±8.9 years). Majority were Rutherford 5 severity (41/50; 82%). Co-morbidities included diabetes mellitus (47/50; 94.0%), end-stage renal failure (25/50; 50.0%), and hypertension (44/50; 88%). 66 atherosclerotic lesions were treated (47 de novo and 19 restenotic; 60.6% TASC C and 39.4% TASC D). Mean lesion length treated was 13.7±9.5cm. There was 100% technical success. There were 3/66 (4.5%) bailout stenting for severe flow limiting dissections. 12-month primary tibial patency was 34/49 (69.4%) and freedom from TLR was 40/49 (81.5%). AFS was 74.0% (37/50). At 12 months, mean Rutherford scores improved from 100% (Rutherford score>3) at baseline to 31% at 12 months (p<0.05) and wound healing rate was 65.7%.

CONCLUSIONS

The iVascular LuminorTM DCB is safe and efficacious in treating highly complex infra-popliteal atherosclerotic lesions in an otherwise challenging frail population of CLTI patients from Singapore.

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.

The modified frailty index-11 predicts medium-term outcomes after endovascular revascularisation for chronic limb threatening ischaemia in Asian patients

OBJECTIVE

The aim was to evaluate the utility of frailty, as defined by the modified Frailty Index-1 1 (mFI-11) on predicting outcomes following endovascular revascularisation in Asian patients with chronic limb-threatening ischaemia (CLTI).

METHODS

CLTI patients who underwent endovascular revascularisation between January 2015 and March 2017 were included. Patients were retrospectively scored using the mFI-11 to categorise frailty as low, medium or high risk. Observed outcomes included 30-day complication rate and unplanned readmissions, 1-, 6- and 12-month mortality, and ambulation status at 6- and 12 months post-intervention.

RESULTS

A total of 233 patients (250 procedures) were included; 137 (58.8%) were males and the mean age was 69.0 (±10.7) years. 202/233 (86.7%) were diabetic and 196/233 (84.1%) had a prior diagnosis of peripheral arterial disease (PAD). The mean mFI-11 score was 4.2 (±1.5). 28/233 (12.0%), 155/233 (66.5%), and 50/233 (21.5%) patients were deemed low (mF-11 score 0-2), moderate (mFI-11 score 3-5) and high (mFI-11 score 5-7) frailty risk, respectively. High frailty was associated with an increased 12-month mortality (OR 8.54, 95% CI 1.05-69.5; p = 0.05), 30-day complication rate (OR 9.41, 95% CI 2.01-44.1; p < 0.01) and 30-day unplanned readmission (OR 5.06, 95% CI 1.06-24.2; p = 0.04). Furthermore, a high score was associated with a significantly worse 6- (OR 0.320, 95% CI 0.120-0.840; p = 0.02) and 12-month (OR 0.270, 95% CI 0.100-0.710; p < 0.01) ambulatory status.

CONCLUSION

The mFI-11 is a useful, non-invasive tool that can be readily calculated using readily available patient data, for prediction of medium-term outcomes for Asian CLTI patients following endovascular revascularisation. Early recognition of short- and mid-term loss of ambulation status amongst high-frailty patients in this challenging cohort of patients could aid decision-making for whether a revascularisation or amputation-first policy is appropriate, and manage patient and caregiver expectations on potential improvement in functional outcome.

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.