Comparison of processed bovine internal mammary arteries and autologous veins as arterial femoral substitutes in dogs: blood compatibility and pathological characteristics.

This study was undertaken to compare the chemically processed internal mammary artery (BIMA) and the autologous femoral vein as arterial grafts. The BIMA prosthesis was implanted as a left femoral artery bypass and the femoral vein as a right femoral artery bypass graft in 27 dogs. In groups of three dogs the grafts were implanted for predetermined durations: 4, 24 and 48 hours (short term), 1, 2 and 4 weeks (medium term) and 3, 6 and 9 months (long term). All autologous veins were patent when the dogs were killed. The patency rates of the BIMA grafts were 100% in the short-term group, 67% in the medium-term group and 29% in the long-term group. The deposition of labelled fibrinogen and platelets on flow surfaces, the structural preservation of the wall of the BIMA prosthesis and accumulation of thrombi during the period of implantation were studied.