Longitudinal micro-incision creation prior to balloon angioplasty for treatment of arteriovenous access dysfunction in a real-world patient population: 6-month cohort analysis

INTRODUCTION

Routine hemodialysis depends on well-functioning vascular access. In the event of vascular access dysfunction, percutaneous transluminal balloon angioplasty (PTA) is conducted to restore patency. Although an angioplasty procedure can provide an excellent immediate result by opening the access to allow dialysis to continue, the long-term patency rates are less than satisfactory. The goal of this study was to assess the outcomes of patients who underwent a novel vessel preparation via longitudinal, controlled-depth micro-incisions prior to PTA.

METHODS

This multicenter, prospective, observational registry enrolled hemodialysis patients scheduled to undergo PTA of their arteriovenous fistula or graft due to clinical or hemodynamic abnormalities. A primary endpoint was anatomic success, defined as angiographic confirmation of <30% residual stenosis post-procedure without an adverse event. Additional assessments included device technical success, clinical success, freedom from target lesion revascularization, target lesion primary patency, and circuit primary patency at 6 months.

FINDINGS

A total of 148 lesions were treated with the FLEX Vessel Prep™ System (FLEX VP) prior to PTA in 114 subjects at eight clinical sites. Target lesions were 21 ± 25 mm in length with mean pre-procedure stenosis of 75.2% ± 4.7%. Five procedural complications were recorded without serious adverse events. Two subjects did not complete the follow-up evaluation. Target lesion primary patency across all subjects at 6-months was 62.2% with mean freedom from target lesion revascularization of 202.7 days. Target lesion primary patency and freedom from target lesion revascularization for AVF cases (n = 72) were 67.5% and 212.9 days, respectively. Target lesion primary patency and freedom from target lesion revascularization for AVGs (n = 42) were 52.4% and 183.3 days, respectively. In cases treating AVF cephalic arch stenosis (n = 25), 6-month target lesion primary patency was 70.6% and freedom from target lesion revascularization was 213.4 days.

DISCUSSION

This FLEX-AV registry demonstrates safety and effectiveness, notably in the cephalic arch and AVGs, when FLEX VP is used prior to PTA for treatment of vascular access dysfunction in a population of end-stage renal disease subjects.

Device profile of the FLEX Vessel Prep System for the treatment of peripheral arterial disease: overview of its safety and efficacy

INTRODUCTION

The standard endovascular treatment for obstructed peripheral arterial disease (PAD) lesions and stenosed arteriovenous (AV) fistulae is percutaneous transluminal angioplasty (PTA). Despite consistent effectiveness in restoring blood flow, PTA does introduce risk of uncontrolled dissections that require stenting. The FLEX Vessel Prep™ System (FLEX VP) is a novel, dynamic, self-sizing, nonballoon device designed to modify obstructive stenoses and plaque, improve vessel compliance and facilitate delivery of drug therapies by creating longitudinal, controlled-depth, circumferential microincisions along the entire length of a lesion.

AREAS COVERED

In this profile, the mechanism of action of the FLEX VP system is described and differentiated. Acute procedural complications and long-term clinical outcomes following FLEX VP+PTA are presented. Specifically, the unmet clinical need for safe and effective vessel preparation in long, complex, mixed morphology PAD lesions is highlighted.

EXPERT OPINION

The FLEX VP system is an innovative approach to create predictable and consistent longitudinal microincisions in long lesions that improve acute luminal gain and vessel compliance by releasing circumferential tension in the lesion. This nonballoon-based device for plaque modification is safe, effective, easy-to-use, and minimizes PTA-associated dissections, therefore reducing stenting, supporting the 'leave nothing behind' incentive of physicians, and improving long-term clinical outcomes with less vessel trauma.

Arterial Preparation by Longitudinal Micro-Incisions Before Balloon Angioplasty of the Superficial Femoral and Popliteal Artery: Acute and 12-Month Results

PURPOSE

Percutaneous transluminal angioplasty (PTA) with conventional plain old balloon (POBA) and/or drug-coated balloon (DCB) is the primary intervention to treat peripheral artery stenoses. However, acute dissections during the procedure and potential for future target lesion revascularization remain procedural complications. The purpose of this study was to assess the acute and 12-month outcomes in patients who underwent novel vessel preparation with longitudinal, controlled-depth micro-incisions prior to PTA.

MATERIALS AND METHODS

Patients with symptomatic lower extremity peripheral arterial disease with a Rutherford class of 2 to 6 and >70% de novo stenosis of the superficial femoral or popliteal arteries were included in this retrospective study. Patients with thrombotic or embolic lesions, restenosis, or in-stent restenosis were excluded. The FLEX Vessel Prep System (FLEX VP) was used to prepare the vessel prior to PTA by creating micro-incisions at the target lesion. The FLEX VP was followed by POBA or paclitaxel DCB.

RESULTS

The study included 65 patients. Lesion characteristics were 90% median stenosis (range = 70%-100%), 75.4% mild-to-severe calcifications, and 33.8% occlusion rate, and median lesion length was 196 (range = 10-480) mm. Following vessel preparation, 82.1% of the patients had low severity dissection or no flow-limiting dissection. The provisional stent rate postprocedure was 16.9%, with a median stent length of 60 mm. The freedom from target lesion revascularization (FFTLR) in 63 evaluable patients at 6 and 12 months was 98.4% and 93.7%, respectively. Freedom from amputation was 100%.

CONCLUSION

In this real-world/all-comers patient population with long, stenotic lesions across the calcification spectrum, vessel preparation with longitudinal micro-incisions prior to PTA was associated with low dissection rate, low dissection severity, low stent implantation, and high FFTLR with the absence of amputation at 12 months relative to published reports in long-lesion cohorts. These results support vessel preparation via micro-incisions.

Vessel Calcification as a Risk Factor for In-Stent Restenosis in Complex Femoropopliteal Lesions After Zilver PTX Paclitaxel-Coated Stent Placement

Purpose: To evaluate the effect of vessel calcification on in-stent restenosis (ISR) after drug-coated stent (DCS) placement in the femoropopliteal segment. Materials and Methods: A retrospective multicenter study was undertaken involving 220 consecutive symptomatic patients (mean age 73.1±8.3 years; 175 men) with femoropopliteal lesions in 230 limbs treated with the Zilver PTX DCS and having duplex surveillance after the endovascular procedures. Mean lesion length was 16.4±9.8 cm (range 2–40); there were 104 (45.2%) total occlusions and 68 (29.6%) in-stent restenoses (ISR). Twenty (8.7%) vessels had no runoff. The majority of lesions (148, 64.3%) were calcified according to the peripheral arterial calcium scoring system (PACSS). Primary patency was evaluated by duplex. Lesions were classified as either PACSS 0–2 (none or unilateral wall calcification) or PACSS 3 and 4 (bilateral wall calcification). Multivariate analysis was performed to identify variables associated with ISR; the results are given as the hazard ratio (HR) and 95% confidence interval (CI). Results: The 1-, 2-, and 5-year primary patency and freedom from clinically-driven target lesion revascularization estimates were 75.9%, 63.6%, and 45.0%, and 84.7%, 73.7%, and 54.2%, respectively. Major amputations were performed on 4 limbs during follow-up. In multivariate analysis, vessel calcification (adjusted HR 1.718, 95% CI 1.035 to 2.851, p=0.036) was significantly correlated with the occurrence of ISR, along with lesion length (adjusted HR 1.041, 95% CI 1.013 to 1.070, p=0.003), and cilostazol administration (adjusted HR 0.476, 95% CI 0.259 to 0.876, p=0.017). Conclusion: This study suggested that bilateral vessel wall calcification was an independent risk factor for ISR in complex femoropopliteal lesions after Zilver PTX DCS placement, along with lesion length; cilostazol administration had a protective effect.