Sixty argon laser-assisted anastomoses in rats: Macroscopic and histological studies

The present in vivo study was undertaken to evaluate the patency rate and histological appearance of 30 venous anastomoses and 30 carotid anastomoses in Wistar rats using a laser. An argon laser was used with the following parameters: power, 100 mW; time, 3 seconds; continuous mode; spot, 200 μm (fluence, 950 J/cm2; irradiance, 320 W/cm2). The macroscopic appearance and patency rate were evaluated at different postoperative intervals (30 days and 60 days). In the venous group, the patency rate was 100% with no saccular pseudo‐aneurysm. In the arterial group, the patency rate was 93% with three saccular pseudo‐aneurysms and two thromboses. Histological studies noted slight and transitory modifications of the media in the arterial group. In the venous group, the modifications appeared under the endothelium. Since the procedure was similar in both groups, the lack of pseudo‐aneurysm formation in the venous group can be explained by a lower intravascular pressure. © 1995 Wiley‐Liss, Inc.