Peculiarities of vitalization of grafts made of porous polytetrafluoroethylene in reconstruction of major veins (an experimental study).

Increased incidence of locally disseminated malignant neoplasms with invasion of major veins compels modern surgery to search for an optimal material for reconstruction of major veins. Presented herein are the results of an experimental study aimed at exploring patency and peculiarities of vitalization of grafts made of porous polytetrafluoroethylene (7th generation, 2010) manufactured by the Closed Joint Stock Company 'Research and Production Complex 'Ecoflon' (St. Petersburg, Russia) with an internal diameter measuring 4.0 mm and used for reconstruction of major veins and arteries with a follow up period up to 270 days. Vitalization of porous polytetrafluoroethylene grafts in the venous position is comparable to that in the arterial position, having similar patterns. Both in the arterial and venous position, vitalization of the graft proceeds at the expense of 'crawling' of the neointima from the anastomoses to the centre of the graft. To distinctive peculiarities of vitalization of grafts in the venous position belong statistically significantly larger thickness of the neointima in the venous position at all stages of the study, lack of statistically significant difference of the neointimal thickness near the edges and in the central part of the graft in the venous position at 270 days. Neither thromboses nor haemodynamically meaningful stenoses of the porous polytetrafluoroethylene grafts and anastomoses in the venous position, despite low velocity of blood flow and its laminar pattern, were observed at any terms of follow up. The obtained findings are indicative of the possibility and validity of using porous polytetrafluoroethylene grafts for reconstruction of major veins in clinical practice.