Microvascular anastomosis has become an essential technique m reconstructive surgery. A patent microvascular anastomosis is required for the success of a free tissue transfer. As the application of microsurgery grows, the desirability of performing an end to end and end to side anastomosis continues to be debated. This experimental study presents the comparison of patency rate of two types of microvascular anastomosis techniques : side to side anastomosis and end to end anastomosis.

A comparative study was undertaken to evaluate side to side micro anastomosis technique using intraluminal catheter. In this study, two clinical metods of microvascular anastomosis were compared. We compared the patency rate and time required for anastomosis. Histological changes (postoperative 1 weeks) were also invsetigated.

Postoperative patency rate was 90% by side to side technique compared to 100% by end to end technique at immediate postoperative and postoperative two weeks. This study revealed that there was no significant difference in patency rate among end to end suture method group and side to side suture method group. Microscopically, we found the relatively smooth surface of the anastomosis site with endothelial regeneration and partial hyaline degeneration in the group using side to side anastomotic method.

We believe there are many advantages in this side to side technique by using intraluminal catheter in perforater flap field and can be highly competitive to the other microvascular anastomisis techniques.

There have been many parameters that determined the results of radiocephalic ffisutla. However, few reliable intraoperative parameters have been suggested until now. The purpose of this study was to find the correlation between intra-operative blood flow and early patency of radiocephalic fistula.

Between March 1998 and October 1999, 45 radiocephalic arteriovenous fistulas were constructed in 38 patients. Intra-operative blood flow measurements were made 10 minutes after complection of the vascular anastomoses with 3-4mm handheld flow probes. Patients were followed until failure of fistula or 3months after first hemodialysis with these fistulas. Intraoperative blood flow as well as age, sex, presence of diabetes, size of cephalic vein, thrill on the fistula and flow of radial artery were correlated with early patency.

The mean intraoperative blood flow was 195.9±16.7 mL/min ranged from 50 to 500 mL/min, and it was the only significant parameter that determined early patency of radiocephalic fistula. Fistulas with flow less than 150 ml/min(10 of 18) revealed higher failure rate than those of flow more than 150 ml/min(1 of 27), which was statistically significant(p<0.01). All of the patients with flow less than 70 ml/min(5 of 5) failed in maintaining patency within a month. However, the other variables were not correlated with early patency.

In conclusion intra-operative blood flow measurements can be performed with ease and intraoperative blood flow in radiocephalic fistula is well correlated with early patency of the fistula. And we rocommend that radio-cephalic fistula of flow less than 150mL/min should be observed carefully and that of flow less than 70mL/min must be abandoned intraoperatively.