Related Experiment Video
Updated: Feb 11, 2026

A Training and Testing System for Performing Vascular Reconstruction In Vitro
Published on: October 26, 2019
In Vivo Evaluation of Short-Term Performance of New Three-Layer Collagen-Based Vascular Graft Designed for Low-Flow
Tomas Grus1, Lukas Lambert2, Mikulas Mlcek3
1Department of Cardiovascular Surgery, First Faculty of Medicine, Charles University and General University Hospital in Prague, U Nemocnice 2, 128 08 Prague 2, Czech Republic.
Aim:
The aim of this study was to evaluate short-term patency of the new prosthetic graft and its structural changes after explantation.
Methods:
The study team developed a three-layer conduit composed of a scaffold made from polyester coated with collagen from the inner and outer side with an internal diameter of 6 mm. The conduit was implanted as a bilateral bypass to the carotid artery in 7 sheep and stenosis was created in selected animals. After a period of 161 days, the explants were evaluated as gross and microscopic specimens.
Results:
The initial flow rate (median ± IQR) in grafts with and without artificial stenosis was 120 ± 79 ml/min and 255 ± 255 ml/min, respectively. Graft occlusion occurred after 99 days in one of 13 conduits (patency rate: 92%). Wall-adherent thrombi occurred only in sharp curvatures in two grafts. Microscopic evaluation showed good engraftment and preserved structure in seven conduits; inflammatory changes with foci of bleeding, necrosis, and disintegration in four conduits; and narrowing of the graft due to thickening of the wall with multifocal separation of the outer layer in two conduits.
Conclusions:
This study demonstrates good short-term patency rates of a newly designed three-layer vascular graft even in low-flow conditions in a sheep model.
Related Concept Videos
Seedless Vascular Plants
Vascular Spasm
Overview of the Vascular System
Vascular Resistance
The primary determinants of vascular resistance are vessel diameter, blood viscosity, and vessel length. Among these, vessel diameter plays the most significant role due to the fourth power relationship described by...
Non-vascular Seedless Plants
Inflammatory Response I: Vascular and Cellular

