6-Month Pivotal Results of Tack Optimized Balloon Angioplasty using the Tack Endovascular System® in Below-the-Knee Arteries

Abstract Objective There is no vascular implant commercially available in the U.S. to treat post-angioplasty dissections in below-the-knee (BTK) arteries. The Tack Endovascular System® is purpose-built to repair post-percutaneous transluminal angioplasty (PTA) BTK dissections. A trial was conducted to investigate the safety and efficacy of the first-of-a-kind implantable BTK device to treat post-PTA dissections in the setting of critical limb ischemia. Methods This prospective, single arm, multi-center study evaluated the Tack Endovascular System for treating post-PTA dissections in the mid/distal popliteal, tibial, and peroneal arteries. The primary safety endpoint is major adverse limb events (MALE) + perioperative death (POD), assessed at 30 days post index procedure; the primary efficacy endpoint is a composite of major adverse limb events (MALE) at 6 months and POD; and the unpowered secondary endpoint is primary patency at 6 months. With no available on-label comparator, the primary endpoints of this trial were determined using objective performance goals (OPGs) from a systematic literature search. Secondary endpoints included Tacked segment(s) patency and target limb salvage (TLS) at 6 months. Six-month results are reported. Results Of the 233 patients enrolled, 50.2% (117/233) were Rutherford 5, and 33.5% (78/233) were Rutherford 4. 341 post-PTA dissections were treated. Each patient received at least one Tack implant, and 100% of dissections were resolved per angiographic core laboratory. Both primary safety and efficacy endpoints were met: MALE + POD at 30 days was 1.3% (3/228), and freedom from MALE at 6 months + POD at 30 days was 95.6% (196/205). Six-month Tacked segment patency was 82.1% (247/301) and TLS was 98.5% (202/205). Kaplan-Meier freedom from CD-TLR and amputation-free survival at 6 months were 92.0% and 95.7%, respectively. Rutherford improvement was reported in 79.4% (158/199). Most (90/122, 73.8%) pre-existing wounds were healed or improving. Conclusions The Tack Endovascular System is safe and effective for treating post-PTA BTK dissections through six months, with favorable rates of MALE + POD, patency, CD-TLR, limb salvage, and wound healing.