Neo-endothelialisation of PTFE microvascular grafts: a five-year experience.
This paper presents the results of a 5-year experience of the implantation of 1 mm diameter polytetrafluoroethylene (PTFE) prosthesis in rodents. By evaluating the implanted grafts at different intervals, the process of neo-endothelial healing can be divided into six phases: Platelet Aggregation Phase (Stage I); Fibrin Network Phase (Stage II); Bridging Phase (Stage III); Progression Phase (Stage IV-A); Transmural Migration Phase (Stage IV-B) (only in optimal grafts, with thin wall and long fibril length); Intimal Closure Phase (Stage V); and Endothelial Thromboresistance Phase (Stage VI). Grafts with 60 or 90 microns fibril length offer enough "anchoring space" for the ingrowth of neo-endothelium and they act as a framework for the neo-endothelial invasion. Furthermore, this type of material allows intramural migration and penetration of cellular elements. In particular, a network of capillaries traversing the graft wall and opening eventually on the luminal surface can provide multiple sources of neo-endothelium, contributing to the development of the inner neo-endothelial lining. Scanning electron microscopy can favourably assist in the evaluation of different types of PTFE grafts, with regard to their fibril length, diameter, and wall thickness.
Department of Orthopaedics, University of Milan, Monza, Italy.
M
M
Lanzetta
E R
ER
Owen
D001807:Blood Vessel Prosthesis; D004730:Endothelium, Vascular / Q000502:physiology*; D006801:Humans; D010974:Platelet Aggregation; D011138:Polytetrafluoroethylene; D011474:Prosthesis Design; D012038:Regeneration
D011138:Polytetrafluoroethylene