Development of sutureless vascular connecting system for easy implantation of small-caliber artificial grafts

Abstract

A novel sutureless vascular connecting system, an assembly with a delivery rod, an introducing sheath, and a connecting device, was developed for easy implantation of small-caliber vascular grafts less than 2 mm in internal diameter. A microporous stainless tube (length 2 mm, external diameter 1.6 mm, wall thickness 65 microm, pore diameter 400 microm, pore-to-pore distance 500 microm) was designed to serve as a connecting device. The feasibility of the system was tested using two types of preliminary animal experiments. One animal model consisted of graft implantation into the rat abdominal aorta (1.5 mm in diameter). The connecting device was inserted into the proximal and distal ends of the aorta through the introducing sheath by pushing the delivery rod with the connecting device placed over it. Subsequently, the aortic segments were inserted into both ends of model grafts made of segmented polyurethane (1.8 mm in internal diameter) and were fixed with banding silk threads from the exterior. The procedure was completed within 20 min without requiring specialized microsurgery techniques. Blood leakage and obstruction did not occur. The second model consisted of an end-to-end anastomosis between rabbit common carotid arteries (2 mm in diameter), which was performed within several minutes of blood flow interruption. Scanning electron microscopy demonstrated that the luminal surface of the device was fully covered with endothelial cells (ECs) after 1 week as a result of transluminal ingrowth of native ECs through the micropores in the device. This endothelialization may prevent early thrombus-induced occlusion. This simple and "easy-to-learn" technique will promote the development of small-caliber arterial grafts, and furthermore, it may have potential for clinical application.

Development of salmon collagen vascular graft: Mechanical and biological properties and preliminary implantation study

“…The SC‐G was preliminarily implanted into the rat abdominal aorta in an end‐to‐end fashion. Anastomosis was performed using a vascular connecting system developed by us 18. Using this system, graft implantation was completed within several minutes of blood flow interception [Figure 5(a)].…”

“…The rats were anesthetized with isoflurane (concentration, 1.5% and flux, 500 mL/min; Nissan Chemical) and were administered heparin (400 unit/kg, Aventis, Tokyo, Japan). The connecting devices were placed into the proximal and distal ends of the trimmed aorta by using a combination of delivery rod and its introducing sheath, as previously described 18. Subsequently, the treated aortic ends were inserted into the graft, followed by banding from the outside of the graft with 4‐0 silk thread (Alfresa, Osaka, Japan).…”

Water‐soluble argatroban for antithrombogenic surface coating of tissue‐engineered cardiovascular tissues

“…After 4 weeks, the implants were harvested with surrounding connective tissues Biotubes were obtained from the implants after the rods were pulled out. Following the adsorption of WSA by immersion of the biotubes in a WSA/saline solution (volume, 4 mL; concentration, 5 mg/mL) for 10 min, the WSA‐treated tubes were auto‐implanted into the infrarenal abdominal aorta of the same rats by end‐to‐end anastomosis and a custom‐designed sutureless vascular connecting system under microscopic guidance 23. Patency was examined at the time of surgery by direct inspection.…”