Fallopian Tube Occlusion with Use of a Small Intestine Submucosa Device: Evaluation in a Rabbit Model

Abstract

The present study evaluates the short- and midterm efficacy of a small intestinal submucosa (SIS) device for fallopian tube occlusion in rabbits. In a pilot study, several SIS device designs were tested for positional stability (absence of migration). The design selected for further testing consisted of a center of spongy SIS surrounded by an SIS sheet and held together by a 0.006-inch wire helix with two barbs. It was delivered on the tip of a short coaxial 3-F/5-F catheter set. Using this design, bilateral transuterine fallopian tube occlusion was performed in eight New Zealand White rabbits. Follow-up consisted of plain radiography at 2 weeks and hysterosalpingography at 6 weeks (n = 4 animals; eight tubes), 12 weeks (n = 2 animals; four tubes), or 24 weeks (n = 2 animals; four tubes). Thereafter, the animals were killed and the fallopian tubes were harvested for histologic evaluation. A single device was placed successfully in each fallopian tube. Fifteen of 16 devices (94%) remained in place throughout follow-up. One device migrated into the vagina at 2-week follow-up. Hysterosalpingography of the 15 tubes with occluders in place showed occlusion in seven of seven (100%) at 6 weeks, three of four (75%) at 12 weeks, and two of four (50%) at 24 weeks. Histologic evaluation revealed luminal occlusion by reorganized SIS containing macrophages, fibrocytes, and scant foreign-body giant cells. Only a mild inflammatory reaction was observed around the tube. In the animals with recanalization at 12 and 24 weeks, new channels were found alongside the original still-occluded fallopian tube lumen. The original lumen of the fallopian tube was effectively occluded by the SIS occluder, which was remodeled within the fallopian tubes of rabbits. Partial peripheral recanalization was observed over time.