Morphological analysis of microarterial media repair after 830 nm diode laser assisted end-to-end anastomosis: Comparison with conventional manual suture.

A series of 240 diode laser assisted end-to-end microvascular anastomoses (LAMA) and conventional manual anastomoses (CMA) were performed in the left and right common carotid of Wistar rats, respectively. In comparison with the two anastomotic methods, optic and scanning electron microscopic examinations were achieved from Day 0 to Day 210, in order to clarify the mechanism of media repair after diode laser welding, especially the long-term results. In the LAMA group, the cut vessel edges were welded without obvious thermal necrosis after laser treatment. On Day 10, media repair was underlined by circular bulges corresponding to the folds of cut vessel endings brought together. Inflammatory cells were regularly scattered in the adventitia in the vicinity of the anastomotic site, and were gaining ground intensively in the media by Day 20. At this time, the parallel organization of elastic laminae disappeared while the collagen network developed. On Day 120, irregular elastic fibres aggregated in the anastomotic site. On Day 210, reconstituted elastic lamina was present. In the CMA group, on Day 20, fibrotic repair appeared between cut vessel edges, and the injury incorporated by sutures was important. The elastic laminae were not reconstituted by Day 210 in any case. This microscopic study proves that the long-term repair of diode LAMA facilitates media repair and prevents fibrotic scarring of the media.