Anastomosis of small veins with suture or Nakayama's apparatus. A comparative study

In controlled experiments, the posterior facial veins in the rabbits neck (diameter 1.5-2.0 mm) were repaired, either by manual suture with 10-0 nylon or by the use of Nakayama's ring pin stapler. The so-called Nakayama "animal" rings, made from metal alloy, as well as the "human" rings, made from tantalum, were employed. A Nakayama anastomosis was performed in only one-third of the time required to complete a suture anastomosis. Evaluation of anastomotic patency was carried out after 7 days, and the vessels were examined histologically in serial sections. Veins anastomosed by the Nakayama technique had a statistically significant lower rate of early thrombosis than the sutured veins, while no difference was found in the occurrence of late thrombosis. The histological analysis showed a perfect endothelium-to-endothelium coaptation in the Nakayama anastomoses, and endothelium covered the anastomotic site in one week. In suture anastomoses the histological picture was more complex, with disintegration of the layers of the vessel wall and hyaline degeneration betweeen sutures. The "animal" rings almost constantly caused local phlebitis, but these changes were not reflected in the patency rates at one week.