Transcervical hysteroscopic sterilization using cyanoacrylate: a long-term experimental study on sheep

We investigated the transcervical hysteroscopy application of n-butyl-2-cyanoacrylate in the uterine tube lumen of a non-rodent animals (sheep) with fallopian tube dimensions similar those in humans.

Standard hysteroscopic procedures were performed on female Texel sheep (n = 26). The right and left ostia were identified. For each ewe, a urethral catheter (5Fr) was used for the delivery of 0.5 mL of saline or an equal volume of n-butyl-2-cyanoacrylate into the uterine tube. Following the procedure, ewes were housed with males of proven fertility for 90 days (equivalent to 5.5 estrous cycles). Postmortem (dye and burst pressure) and in vivo (hysterosalpingogram) testing for tube patency were both performed 90 days and 180 days following the procedure.

All animals receiving the saline treatment became pregnant. Gross inspection of uterine tubes following n-butyl-2-cyanoacrylate treatment revealed no visceral adhesions or fibrosis. However, postmortem testing revealed total obstruction within the fallopian tubes. This was confirmed by hysterosalpingogram, in that iodine contrast did not escape into the abdominal cavity.

The cyanoacrylate promoted a reliable fallopian tube obstruction without fibrosis in an animal model exhibiting a similar tube diameter to that found in women. The technique can be evaluated for efficacy in vivo using hysterosalpingography.