Merit Medical announced that the six-month results of the Wrapsody Arteriovenous Access Efficacy Trial (WAVE Trial), randomized group, have been confirmed for publication in the April issue of Kidney International, while the twelve-month results of the trial will be officially presented at the 50th Scientific Session of the Society of Interventional Radiology (March 29 to April 2, Nashville, USA).

Wrapsody CIE received premarket approval (PMA) from the U.S. FDA in December 2024 and launched commercialization in the U.S. in January 2025. The device had previously obtained CE certification in the European Union and was launched in Brazil.

1. Background and Technology

Patients undergoing hemodialysis need to establish an arteriovenous fistula (AVF) to achieve a long-term vascular access. However, AVF and surrounding vascular stenosis can interfere with dialysis treatment and even lead to life-threatening consequences. The WRAPSODY™ Cell-Impermeable Endoprosthesis (CIE) is designed to assist clinicians in restoring vascular access function when stenosis occurs in the venous outflow tract of dialysis patients.

Inner layer: The innermost layer of WRAPSODY is made of a biocompatible novel spun polytetrafluoroethylene (PTFE) layer, which reduces fibrin deposition and thrombus formation without the need for coatings, chemicals, or drugs.

Middle layer: The impermeable graft layer, WRAPSODY uses an impermeable intermediate graft layer design that prevents transwall cell migration without the need for drug binding.

Outer layer: The outer layer of WRAPSODY is made of standard biocompatible expanded polytetrafluoroethylene (ePTFE) material, which promotes necessary tissue ingrowth to prevent stent migration.

2. Experimental Design and Results

The WAVE trial is a multicenter, international investigational device exemption (IDE) trial aimed at evaluating the safety and efficacy of the Wrapsody CIE device over a two-year period. In the randomized portion, 245 hemodialysis patients with AVF venous outflow tract stenosis were randomly assigned to receive Wrapsody CIE treatment (n=122) or standard percutaneous transluminal angioplasty (PTA, n=123).

• Efficacy endpoints: the proportion of patients with primary patency of target lesions who do not require intervention due to clinically driven revascularization or thrombosis formation; primary patency of access, defined as the proportion of patients with no loss of vascular access at any site from the initial treatment until the need for reintervention or abandonment of the vascular access.

• Safety endpoint: The primary safety definition is the proportion of patients experiencing reintervention, hospitalization, or death due to adverse events affecting vascular access or venous outflow tract (excluding target lesion revascularization or thrombosis).

• Six-month results: The primary patency rate of target lesions in the Wrapsody CIE group was significantly higher than that in the PTA group (89.8% vs. 62.8%, p<0.0001); the primary patency rate of the access site was also significantly higher (72.6% vs. 57.9%, p=0.015); there were no significant differences in safety between the two groups.

• 12-month results: The primary patency rate of target lesions in the Wrapsody CIE group remains significantly higher than that in the PTA group (70.1% vs. 41.6%, p<0.0001); the primary patency rate of the access site continues to lead (58.1% vs. 34.4%, p=0.0003).

3. Expert Opinions

Dheeraj K Rajan, a researcher from the WAVE trial at the University of Toronto, stated: "The positive one-year results of Wrapsody CIE fill an important knowledge gap regarding the long-term durability of devices. It is encouraging that we now have a new device that can help extend the functional use of patients' vascular access."

Fred P Lampropoulos, Chairman and CEO of Merit Medical, said: "We are pleased to continue the outstanding performance of Wrapsody CIE. Merit is committed to improving patient care and providing clinicians with the data support they need for evidence-based decision making."