A microvascular anastomotic device: Part II. A histologic study in arteries and veins.

This study analyzes the histology associated with the polyethylene ring-pin device. The device was placed in 20 rabbit femoral arteries and 20 femoral veins. Specimens were harvested at 24-hour and 3-week postoperative intervals and were analyzed using light, scanning electron, and transmission electron microscopy. Generally, the reparative process in the arteries and veins was similar. In 24-hour artery and vein specimens, the endothelial cells were absent, the media tapered within the device, but smooth muscle cells (SMC) remained partially viable. In 3-week specimens, the device junction was well healed and reendothelialized. Subintimal hyperplasia was present, the internal elastic lamina was not reconstituted, and the SMCs were partially viable. Small vascular channels formed at the device junction, and small venous valves were noted near the device. Macrophages lined the margins of the device. The early reparative process proceeds favorably, by histologic criteria, after vessel repair with the polyethylene ring-pin device.