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.

The Impact of Multimorbidity Burden, Frailty Risk Scoring, and 3-Directional Morphological Indices vs. Testing for CSF Responsiveness in Normal Pressure Hydrocephalus.

Objective: Multimorbidity burden across disease cohorts and variations in clinico-radiographic presentations within normal pressure hydrocephalus (NPH) confound its diagnosis, and the assessment of its amenability to interventions. We hypothesized that novel imaging techniques such as 3-directional linear morphological indices could help in distinguishing between hydrocephalus vs. non-hydrocephalus and correlate with responsiveness to external lumbar drainage (CSF responsiveness) within NPH subtypes. Methodology: Twenty-one participants with NPH were recruited and age-matched to 21 patients with Alzheimer's Disease (AD) and 21 healthy controls (HC) selected from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database. Patients with NPH underwent testing via the NPH programme with external lumbar drainage (ELD); pre- and post-ELD MRI scans were obtained. The modified Frailty Index (mFI-11) was used to stratify the NPH cohort, including Classic and Complex subtypes, by their comorbidity and frailty risks. The quantitative imaging network tool 3D Slicer was used to derive traditional 2-dimensional (2d) linear measures; Evans Index (EI), Bicaudate Index (BCI) and Callosal Angle (CA), along with novel 3-directional (3d) linear measures; z-Evans Index and Brain per Ventricle Ratio (BVR). 3-Dimensional (3D) ventricular volumetry was performed as an independent correlate of ventriculomegaly to CSF responsiveness. Results: Mean age for study participants was 71.14 ± 6.3 years (18, 85.7% males). The majority (15/21, 71.4%) of participants with NPH comprised the Complex subtype (overlay from vascular risk burden and AD); 12/21 (57.1%) were Non-Responders to ELD. Frailty alone was insufficient in distinguishing between NPH subtypes. By contrast, 3d linear measures distinguished NPH from both AD and HC cohorts, but also correlated to CSF responsiveness. The z-Evans Index was the most sensitive volumetric measure of CSF responsiveness (p = 0.012). Changes in 3d morphological indices across timepoints distinguished between Responders vs. Non-Responders to lumbar testing. There was a significant reduction of indices, only in Non-Responders and across multiple measures (z-Evans Index; p = 0.001, BVR at PC; p = 0.024). This was due to a significant decrease in ventricular measurement (p = 0.005) that correlated to independent 3D volumetry (p = 0.008). Conclusion. In the context of multimorbidity burden, frailty risks and overlay from neurodegenerative disease, 3d morphological indices demonstrated utility in distinguishing hydrocephalus vs. non-hydrocephalus and degree of CSF responsiveness. Further work may support the characterization of patients with Complex NPH who would best benefit from the risks of interventions.

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).

Treatment of cephalic arch stenosis in dysfunctional arteriovenous fistulas with paclitaxel-coated versus conventional balloon angioplasty.

BACKGROUND: Treatment of cephalic arch stenosis (CAS) with standard plain old balloon angioplasty (POBA) in dysfunctional arteriovenous fistulas (AVF), is associated with early re-stenosis and higher failure rates compared to other lesions. Paclitaxel-coated balloons (PCB) may improve patency rates. This is a retrospective cohort study. Patients who underwent POBA or PCB for CAS over a 3-year period were included. Outcomes compared were circuit primary patency rates (patency from index procedure to next intervention), circuit primary assisted-patency rates (patency from index procedure to thrombosis), and target lesion (CAS) patency rates (stenosis > 50%) at 3, 6 and 12 months. RESULTS: Ninety-one patients were included. Sixty-five (71.4%) had POBA, while 26 (28.6%) had PCB angioplasty. There were 62 (68.1%) de-novo lesions. CAS was the only lesion that needed treatment in 24 (26.4%) patients. Circuit primary patency rates for POBA versus PCB groups were 76.2% vs. 60% (p = 0.21), 43.5% vs. 36% (p = 0.69) and 22% vs. 9.1% (p = 0.22) at 3, 6 and 12-months respectively. Circuit assisted-primary patency rates were 93.7% vs. 92% (p = 1.00), 87.1% vs. 80% (p = 0.51) and 76.3% vs. 81.8% (p = 0.77), whilst CAS target lesion intervention-free patency rates were 79.4% vs. 68% (p = 0.40), 51.6% vs. 52% (p = 1.00) and 33.9% vs. 22.7% (p = 0.49) at 3, 6 and 12-months respectively. Estimated mean time to target lesion intervention was 215 ± 183.2 days for POBA and 225 ± 186.6 days for PCB (p = 0.20). CONCLUSION: Treatment of CAS with PCB did not improve target lesion or circuit patency rates compared to POBA.

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 (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.