Robotic microsurgical vasovasostomy and vasoepididymostomy: a prospective randomized study in a rat model

Microsurgical vasovasostomy and vasoepididymostomy remain technically challenging procedures. Refinements in technique have continually improved patency and pregnancy rates for the 2 procedures in experienced hands. Advances in surgical robotics produced the Da Vinci robot (Intuitive Surgical, Inc., Sunnyvale, California) with motion reduction and no tremor, features that may improve outcomes in microsurgery. We report a randomized prospective study of vasoepididymostomy and vasovasostomy using the Da Vinci robot in rats.

A total of 24 adult male Wistar rats underwent vasectomy through a midline abdominal incision. Two weeks later the animals were randomized to microsurgical multilayer vasovasostomy, longitudinal vasoepididymostomy or robotic vasovasostomy and vasoepididymostomy groups. Outcomes measured included surgical time, complications, patency and sperm granuloma formation at 9 weeks.

Animals were sacrificed 9 weeks after microsurgery. There were no significant differences in complications among the groups. Robotic vasovasostomy was significantly faster than the conventional microsurgical technique (68.5 vs 102.5 minutes, p = 0.002). The robotic and microsurgical vasoepididymostomy groups did not differ significantly in time. Patency rates were 100% for the robotic vasovasostomy and vasoepididymostomy groups, and 90% in the microsurgical vasovasostomy and vasoepididymostomy groups. These differences were not significant. Sperm granulomas were found in 70% of microsurgical vasovasostomy anastomoses and 27% of robotic vasovasostomy anastomoses (p = 0.001). No significant difference in the sperm granuloma rate was found between the robotic or microsurgical vasoepididymostomy groups (42% and 50%, respectively, p = 0.37).

To our knowledge we report the first randomized prospective study using the Da Vinci robot for microsurgery. We believe that the improved stability and motion reduction during microsurgical suturing with the robot helped achieve excellent patency rates for vasovasostomy and vasoepididymostomy. The robot may also allow experienced microsurgeons to perform microsurgical procedures in patients at remote locations where no experienced microsurgeons are available.