Absorbable external rings for anastomosis of the fallopian tubes: a feasibility study

A novel approach to tubotubal anastomosis with external, absorbable, ring-shaped devices was evaluated. Fallopian tubes of female Sprague-Dawley rats were transected and coagulated and either left divided or anastomosed with microsurgical technique, with or without external rings. Postoperative patency and pregnancy rates were used to evaluate the procedures. Transected and coagulated fallopian tubes remained occluded at the time of repeated surgery, and no implantations were observed in the corresponding uterine horns. Of ten fallopian tubes anastomosed without the ring, five were patent and five were partially blocked. All ten fallopian tubes anastomosed with the external rings were fully open. Implantation sites were observed in four of ten uterine horns corresponding to fallopian tubes anastomosed without the ring and in eight of ten horns anastomosed with the external ring. The difference was statistically significant, P = to 0.03. All external rings were completely absorbed 7 weeks after anastomosis. The new technique was simpler to perform and was less time-consuming. We conclude that tubotubal anastomosis with external rings may offer advantages over the conventional technique.