# Six-Month Patency of Long Carotid Bypass Grafts Constructed with In-Body Tissue Architecture-Induced Small-Diameter Biotubes in a Goat Model

## TL;DR

This study shows that tissue-engineered Biotube grafts can remain open for six months in goats, offering a potential alternative to traditional vein grafts for blood vessel repair.

## Contribution

The study demonstrates the long-term patency of in-body tissue-engineered small-diameter vascular grafts in a large animal model.

## Key findings

- Six Biotubes remained patent for six months despite exceeding 10 cm in length.
- Histological analysis showed neointima formation, endothelialization, and minimal inflammation.
- One graft developed stenosis and another showed dilatation, indicating areas for improvement.

## Abstract

This study investigated the long-term patency of regenerative Biotube grafts and discusses their feasibility as an alternative to autologous vein grafts for peripheral artery disease. Six Biotubes with a diameter of 4 mm were autologously fabricated in recipients using in vivo tissue engineering (in-body tissue architecture) technology and implanted as carotid artery bypass grafts in a goat model. All six grafts remained patent at 6 months despite exceeding 10 cm in length, demonstrating their biocompatibility and durability. Histological analysis revealed neointima formation, endothelialization, and minimal inflammation. However, in one goat, a graft developed stenosis, while another showed dilatation. These findings demonstrate the use of Biotubes as a viable option for peripheral vascular reconstruction as tissue-engineered vascular grafts. However, further optimization is needed to address emerging issues with their use, such as stenosis and aneurysm formation, to improve long-term patency.