Morpho-Pathological Review on the Healing of Synthetic Vascular Grafts

Objective: Tissue integration of vascular grafts partially depends on the host response to injury, which immediately begins after implantation and restoration of the circulation. In an infected environment, the inflammation changes the incorporation patterns. The aim of the study was to observe the tissue incorporation process, in a normal and an infected environment. Methods: We have created an experimental model by performing subfascial implantation of four types of vascular grafts, in rats (woven Dacron®, knitted Dacron®, silver coated Dacron® and expanded Polytetrafloroethylene - ePTFE) and by infecting some of them with three different bacterial strains. We have retrieved the noninfected grafts at two and four weeks after implantation, whilst the infected ones at one, two and three weeks. Results: Detailed microscopic appearences were analysed. The control and infected groups were compared. Statistical significance was calculated for various corelations. Conclusions: The morphopathological findings showed that the ePTFE graft’s structure was best preserved. Statistical significance existed between the bacterial strain and the degree of inflammation. The silver coated Dacron® was not shown to be superior to the knitted Dacron®. The poorest incorporation was the one of the woven Dacron®