EXPANDABLE PROSTHESIS FOR SUTURELESS ANASTOMOSIS IN THORACIC AORTA PROSTHETIC SUBSTITUTION

Objective. Most complications of descending aorta prosthetic substitut ion seem mainly to be related directly (ischemia to distal organs, i.e . liver, kidney, spinal cord) or indirectly (extracorporeal circulatio n or shunts and systemic heparinization complications) to the duration of blood flow interruption. The purpose of this study is to report th e results of animal experimentation of a new device for sutureless pro sthetic substitution of the descending thoracic aorta, with a very sho rt crossclamping phase. Methods. The device consists of expandable loo ps of stainless steel wires, sewn to the proximal end of a Dacron pros thesis. The stainless steel wire loops can be expanded and tightened b y activating a removable guide in such a way that the prosthesis varie s its diameter, while maintaining a regular cylindrical shape. The dev ice was prepared in two different configurations, one for long segment s (expandable prosthesis end) and the other to be used for very short segments or as an anastomotic ring between prosthetic or vascular stum ps (quick anastomotic ring). The expandable prosthesis end was tested in swine experiments by performing the prosthetic substitution of the first 10 cm of descending cross-clamped aorta, the prosthesis being fi xed with the device both at the proximal and the distal ends (six expe riments). All animals survived the procedure, that was accomplished wi th a very short crossclamping time. The quick anastomotic ring was use d to anastomose two prosthesis ends, at the middle of the prosthetic s egment used for descending aorta substitution (two swine), to perform the distal anastomosis in the same model of descending aorta substitut ion (one swine) and simply to re-anastomose a subtotally transected de scending aorta (one swine). Results. The present experience proved the reliability of the device to carry out a sutureless, accurate, simple and quick anastomosis. Its advantage over an intraluminal ringed pros thesis is much easier insertion of the retracted wired end into the va scular stumps, thus allowing for a prosthetic diameter appropriate to the substituted vessel. Conclusions. The reduced crossclamping feature of the device would suggest its use mainly in thoracic aorta prosthet ic substitution for the prevention of ischemic damage to distal organs ; it can also be used to advantage wherever an end-to-end vascular or prosthetic anastomosis is indicated, providing an accurate, stented an astomosis.