# Experimental comparative study of a novel drug-eluting arteriovenous graft in a sheep model

## TL;DR

A new drug-eluting graft was tested in sheep but failed to maintain patency due to age-related deterioration despite reducing neointimal growth.

## Contribution

A novel drug-eluting graft prototype using a zwitterion-bounded interpenetrating polymer network was experimentally tested in a sheep AV graft model.

## Key findings

- The IPN graft showed no neointimal hyperplasia in 11 sheep after 12 months compared to 9 out of 11 in ACUSEAL grafts.
- Despite reduced neointimal growth, the IPN grafts deteriorated severely over time.
- Most grafts occluded within 12 months, indicating poor long-term patency.

## Abstract

Arteriovenous (AV) grafts often develop severe complications of stenosis due to neointimal proliferation that occurs either at the venous anastomosis site or at the outflow receiving vein. This study compares primary patency during 12 months of follow up for a new experimental Biomodics© interpenetrating polymer network (IPN) drug-eluting graft prototype with state-of-the-art GORE® ACUSEAL (ACUSEAL) in an AV graft model in sheep.

An end-to-end bypass from the common carotid artery to the jugularis vein was performed bilaterally in 12 sheep. The usage of ACUSEAL or the IPN, both 6.0 mm in diameter, was determined via randomization. The sheep were followed up every 4 weeks with ultrasonic duplex scanning to determine patency; the experienced observer was blinded to the randomization. One sheep died after 11 days, and the final sample accordingly consisted of 11 animals. When comparing neointimal hyperplasia after 12 months in the two grafts, Fisher's exact test showed a significant difference with none out of 11 in the IPN grafts and 9 out of 11 in the ACUSEAL graft (p < 0.001). However, the Biomodics© IPN exhibited severe deterioration over time.

Almost all of the grafts occluded during the 12 months of follow up. Although the zwitterion-bounded interpenetrating drug eluting polymer network showed signs to impair neointimal hyperplasia and thrombosis, age-related degeneration hindered demonstrating a potential improvement in patency.