[Morphology of a neonatal umbilical vein graft under prolonged experimental conditions].

The authors carried out a comparative histological and electron microscopic study of the bioprosthesis of the umbilical vein (Biograft manufactured by Meadox) and bioprosthesis obtained according to the method by M. I. Kuzin and coworkers. A far greater preservation of the new bioprosthesis was observed at long-term periods both at the histological and ultrastructural levels. Some morphological phenomena reflecting the time course of the vessel graft rearrangement were delineated 18 to 24 months after transplantation, particularly the development of "collateral" vessels in the perivenous space. The suggestion was made about an important role of Wharton's substance in the formation of the vessels.