Prospective, randomized, multicenter clinical study comparing a self-expanding covered stent to percutaneous transluminal angioplasty for treatment of upper extremity hemodialysis arteriovenous fistula stenosis.

Use of a covered stent after percutaneous transluminal angioplasty (PTA) was compared to PTA alone for treatment of upper extremity hemodialysis patients with arteriovenous fistula (AVF) stenoses. Patients with AVF stenosis of 50% or more and evidence of AVF dysfunction underwent treatment with PTA followed by randomization of 142 patients to include a covered stent or 138 patients with PTA alone. Primary outcomes were 30-day safety, powered for noninferiority, and six-month target lesion primary patency (TLPP), powered to test whether TLPP after covered-stent placement was superior to PTA alone. Twelve-month TLPP and six-month access circuit primary patency (ACPP) were also hypothesis tested while additional clinical outcomes were observed through two years. Safety was significantly non-inferior while six- and 12-month TLPP were each superior for the covered stent group compared to PTA alone (six months: 78.7% versus 55.8%; 12 months: 47.9% versus 21.2%, respectively). ACPP was not statistically different between groups at six-months. Observed differences at 24 months favored the covered-stent group: 28.4% better TLPP, fewer target-lesion reinterventions (1.6 ± 1.6 versus 2.8 ± 2.0), and a longer mean time between target-lesion reinterventions (380.4 ± 249.5 versus 217.6 ± 158.4 days). Thus, our multicenter, prospective, randomized study of a covered stent used to treat AVF stenosis demonstrated noninferior safety with better TLPP and fewer target-lesion reinterventions than PTA alone through 24 months.

Results from the First-in-Human Study of the Caterpillar™ Arterial Embolization System.

PURPOSE: To assess occlusion success and adverse events associated with the use of a self-expanding device for peripheral artery embolization. METHODS: This prospective, single-arm, feasibility study was conducted using the Caterpillar™ Arterial Embolization Device composed of opposing nitinol fibers and a flow-occluding membrane. Twenty patients (24 embolization sites) were treated at four investigational centers in New Zealand and Australia and followed for 30 days. Embolization sites included mesenteric, accessory renal, and iliac arteries and their branches. Primary outcome measures were peri-procedural occlusion confirmed by angiography and freedom from device-related serious adverse events (SAEs) at 30 days. Secondary observations included time to occlusion and assessment of adverse events. RESULTS: Peri-procedural occlusion was 100%, and freedom from a device-related SAE was 94.7% at 30 days. One patient had abdominal bloating that required hospitalization deemed possibly related to the device or procedure. Twenty-two of 24 embolization sites were occluded with one device (91.7%). Mean procedure duration was 11.7 ± 8.6 min (device deployment time: 1.8 ± 1.0 min), and mean fluoroscopy time was 241 ± 290.7 s. All embolization sites occluded during the procedure with 62.5% occluded within three minutes and 91.6% occluded within ten minutes. No devices migrated or required re-embolization. Freedom from device- and procedure-related adverse events was 84.2%. One patient died from aortic rupture during a subsequent adjunctive abdominal aortic endovascular procedure deemed unrelated to the embolization device or procedure. CONCLUSIONS: This first-in-human study of the Caterpillar embolization device achieved peri-procedural occlusion in all patients with a 94.7% freedom from device-related SAE at 30 days. LEVEL OF EVIDENCE: Level 2b-prospective, multicenter, single-arm, first-in-human clinical study. Pre-specified endpoints were analyzed using descriptive statistics.

Prospective, Multicenter Clinical Study of the Covera Vascular Covered Stent in the Treatment of Stenosis at the Graft-Vein Anastomosis of Dysfunctional Hemodialysis Access Grafts.

PURPOSE: To study the use of the self-expanding Covera covered stent for the treatment of stenotic lesions at the venous anastomosis of hemodialysis arteriovenous grafts (AVGs). MATERIALS AND METHODS: A total of 110 patients with AVG venous anastomotic stenosis of ≥50% and access dysfunction were treated at 14 centers in the United States using percutaneous transluminal angioplasty followed by covered stent placement. The primary end points were 30-day safety and 6-month target lesion primary patency (TLPP). The secondary measures included access circuit primary patency, circuit cumulative patency, and the number of reinterventions through 24 months. RESULTS: Freedom from a primary safety event at 30 days was 96.4% while the 6-month TLPP rate was 70.3%. Seventy-five patients completed 24-month follow-up (68.2%). The TLPP rates were 54.2% at 365 days and 36.9% at 730 days while the access circuit primary patency rates were 16.7% at 365 days and 7.8% at 730 days (Kaplan-Meier analysis). The access circuit cumulative patency rates were 85.4% at 12 months and 73.6% at 24 months. The number of reinterventions to maintain the patency of the access circuit was 3.6 ± 3.1 at 24 months (1.6 ± 1.9 at the target lesion). CONCLUSIONS: Use of the Covera covered stent for hemodialysis graft-vein anastomotic stenosis provided a safe treatment option with a TLPP rate of 70.3% at 6 months and TLPP and cumulative access circuit patency rates of 36.9% and 73.6% at 2 years.

Three-Year Results from the Venovo Venous Stent Study for the Treatment of Iliac and Femoral Vein Obstruction.

PURPOSE: To assess safety and patency of the Venovo venous stent for the treatment of iliofemoral vein obstruction. MATERIALS AND METHODS: Twenty-two international centers enrolled 170 patients in the VERNACULAR study (93 post-thrombotic syndrome; 77 non-thrombotic iliac vein lesions). Primary outcome measures were major adverse events at 30 days and 12-month primary patency (freedom from target vessel revascularization, thrombotic occlusion, or stenosis > 50%). Secondary outcomes included the Venous Clinical Severity Score Pain Assessment and Chronic Venous Quality-of-Life Questionnaire assessments (hypothesis tested). Secondary observations included primary patency, target vessel and lesion revascularization (TVR/TLR), and assessment of stent integrity through 36 months. RESULTS: Freedom from major adverse events through 30 days was 93.5%, statistically higher than a pre-specified performance goal of 89% (p = 0.032) while primary patency at 12 months was 88.6%, also statistically higher than a performance goal of 74% (p < 0.0001). Mean quality-of-life measures were statistically improved compared to baseline values at 12 months (p < 0.0001). Primary patency at 36 months was 84% (Kaplan-Meier analysis) while freedom from TVR/TLR was 88.1%. There was no stent embolization/migration, and no core laboratory assessed stent fractures reported through 36 months. Six deaths were reported; none adjudicated as device or procedure related. CONCLUSION: The Venovo venous stent was successfully deployed in obstructive iliofemoral vein lesions and met the pre-specified primary outcome measures through 12 months. At 3 years, primary patency was 84%, reintervention rates were low, standardized quality-of-life and pain measures improved from baseline, and there was no stent migration or fractures. LEVEL OF EVIDENCE: Level 2-prospective, multicenter, controlled clinical study without a concurrent control or randomization. Pre-specified endpoints were hypothesis-tested to performance goals derived from peer-reviewed clinical literature. REGISTRATION CLINICALTRIALS.GOV: Unique Identifier NCT02655887.

Drug-Coated vs Uncoated Percutaneous Transluminal Angioplasty in Infrapopliteal Arteries: Six-Month Results of the Lutonix BTK Trial.

OBJECTIVES: We hypothesized that a drug-coated balloon (DCB) could improve treatment efficacy while maintaining safety when compared with percutaneous transluminal angioplasty (PTA) for the treatment of atherosclerotic infrapopliteal arterial lesions. METHODS: A total of 442 patients with angiographically significant lesions were randomized (2:1) to DCB or PTA. The primary safety and efficacy endpoints were freedom from major adverse limb events and perioperative death (MALE-POD) at 30 days, and freedom from vessel occlusion, clinically driven target-lesion revascularization (CD-TLR), and above-ankle amputation measured at 6 months. Success was achieved if safety between groups was non-inferior (margin 12%), and efficacy was statistically significant either for the overall intention-to treat (ITT) or the proximal-segment DCB groups (ie, the proximal two-thirds of the below-knee arterial pathways). RESULTS: Freedom from MALE-POD for the DCB group (99.3%) was non-inferior to PTA (99.4%; non-inferiority P<.001). Proportional analysis of the primary efficacy endpoint was statistically significant for the proximal-segment DCB group (76%) vs PTA (62.9%; one-sided P<.01; Bayesian P-value for success of .0085) while not statistically significant for the overall ITT group (74.5% for DCB vs 63.5% for PTA; one-sided P=.02). Kaplan-Meier analyses demonstrated superior efficacy for DCB in both the overall ITT and proximal-segment groups at 6 months. Primary patency and CD-TLR, hypothesis-tested secondary endpoints, were also statistically better for the DCB group compared with PTA at 6 months (one-sided P<.025). CONCLUSIONS: DCB treatment for symptomatic infrapopliteal arterial lesions produced non-inferior safety at 30 days and a statistically significant difference in the primary efficacy endpoint when compared with PTA at 6 months.

Balloon-Expandable Vascular Covered Stent in the Treatment of Iliac Artery Occlusive Disease: 9-Month Results from the BOLSTER Multicenter Study.

PURPOSE: This study sought to assess the performance of the LIFESTREAM balloon-expandable covered stent for the treatment of iliac artery atherosclerotic lesions. METHODS: A total of 155 patients were treated in a prospective, single-arm study at 17 centers in the United States, Europe, and New Zealand. The primary endpoint was a composite of device- or procedure-related death or myocardial infarction (MI) over the course of 30 days, or target lesion revascularization (TLR), major amputation of the target limb, or re-stenosis through 9-months. Secondary endpoints included primary patency, TLR, sustained clinical success, quality of life, and major adverse events (MAE). RESULTS: At 9 months, the primary composite endpoint rate was 16.2% (93.5% confidence interval [CI]: 10.6%-23.2%), primary patency was 89.1% (95% CI: 82.6%-93.7%), and freedom from TLR was 96%. There was a cumulative clinical improvement of at least one Rutherford category from baseline to 9 months of 90.5% (95% CI: 84.3%-94.9%). Quality of life, assessed by using the Walking Impairment Questionnaire (WIQ), demonstrated a mean change in total score from baseline through 9 months of 32.1 ± 26.84; overall, improvements were noted from baseline in each WIQ category. Seven of one-hundred fifty patients (4.7%; 95% CI: 1.9%-9.4%) experienced MAEs, but none were determined to be related to device or procedure. CONCLUSIONS: The LIFESTREAM balloon-expandable covered stent provided satisfactory 9-month clinical outcomes including a low rate of target lesion revascularization for the treatment of stenotic and occlusive lesions of the iliac arteries.

Nitinol Self-Expanding Stents for the Treatment of Obstructive Superficial Femoral Artery Disease: Three-Year Results of the RELIABLE Japanese Multicenter Study.

Objective: To assess the use of a nitinol stent to treat symptomatic stenoses or occlusions of the native superficial femoral artery (SFA). Materials and Methods: Seventy-four patients were treated at 12 Japanese sites. The primary endpoint, freedom from target-limb failure (TLF), was a composite of device- or procedure-related death, target-limb amputation, target-vessel revascularization (TVR), or restenosis compared to an objective performance goal (OPG) at 12 months. Secondary endpoints, including primary patency, freedom from TVR/target-lesion revascularization (TLR), improvements in clinical parameters, and major adverse events (MAEs) were evaluated through 36 months. Results: The mean overall lesion length was 80.7±38.9 mm (mean stented length: 98.8±46.1 mm). Freedom from TLF was 81.2% (p<0.001 compared to OPG) with a Kaplan-Meier estimate of 84.2% [95% confidence interval (95%CI) 73.3%, 90.9%] at 12 months. Primary patency was 71.0% at 12 months and 67.8% at 36 months. A total of 94.7% of patients improved by at least one Rutherford category and 70.2% of patients improved ankle-brachial indices ≧0.10 from baseline to 36 months. Freedom from TVR/TLR (Kaplan-Meier) was 90% at 12 months and 79.5% at 36 months. Four MAEs were reported; none were found to be device or procedure related. Conclusion: A self-expanding stent was used safely to treat stenotic and occlusive lesions of the SFA in a Japanese patient population. The composite endpoint, freedom from TLF, was superior to an historical control at one year, with low rates of revascularization and good functional and clinical outcomes through three years.

The DENALI Trial: an interim analysis of a prospective, multicenter study of the Denali retrievable inferior vena cava filter.

PURPOSE: To assess safety and effectiveness of a nitinol retrievable inferior vena cava (IVC) filter in patients who require caval interruption to protect against pulmonary embolism (PE). MATERIALS AND METHODS: Two hundred patients with temporary indications for an IVC filter were enrolled in this prospective, multicenter clinical study. Patients undergoing filter implantation were to be followed for 2 years or for 30 days after filter retrieval. At the time of the present interim report, all 200 patients had been enrolled in the study, and 160 had undergone a retrieval attempt or been followed to 6 months with their filter in place. Primary study endpoints included technical and clinical success of filter placement and retrieval. Patients were also evaluated for recurrent PE, new or worsening deep vein thrombosis, and filter migration, fracture, penetration, and tilt. RESULTS: Clinical success of placement was achieved in 94.5% of patients (172 of 182), with a one-sided lower limit of the 95% confidence interval of 90.1%. Technical success rate of filter placement was 99.5%. Technical success rate of retrieval was 97.3%; 108 filters were retrieved in 111 attempts. In two cases, the filter apex could not be engaged with a snare, and one device was engaged but could not be removed. Filter retrievals occurred at a mean indwell time of 165 days (range, 5-632 d). There were no instances of filter fracture, migration, or tilt greater than 15° at the time of retrieval or 6-month follow-up. CONCLUSIONS: In this interim report, the nitinol retrievable IVC filter provided protection against pulmonary embolism, and the device could be retrieved with a low rate of complications.