Characterization of tubal occlusion after transcervical polidocanol foam (PF) infusion in baboons.

OBJECTIVE: Our long-term goal is to develop a nonsurgical method of fallopian tubal occlusion for the purpose of permanent contraception. We have previously demonstrated that transcervical administration of 5% polidocanol foam (PF) can create tubal occlusion in macaques but that multiple treatments are required. In this study, we assessed the efficacy of various regimens of PF with and without depomedroxyprogesterone acetate (DMPA) (to control ovarian cycle phase) in the baboon. STUDY DESIGN: Adult cycling female baboons were evaluated for tubal patency by hysterosalpingography and then received a transcervical infusion of PF with (+) or without (-) an intramuscular injection of DMPA (3.5 mg/kg). Two concentrations of PF were compared: 1% [(+) DMPA, n=5; (-) DMPA, n=3] and 5% [(+) DMPA, n=4; (-) DMPA, n=3]. Controls received (+) DMPA (n=2) or (-) DMPA, (n=3) only. The reproductive tracts were removed 1-3 months after treatment for examination. RESULTS: No fallopian tubal occlusion was observed in negative controls (±DMPA). Histologic complete tubal occlusion was observed in 3/8 of females treated with 1% PF and in 6/7 treated with 5% PF. Histologic evaluation suggested that 1% PF is associated with prolonged chronic inflammation (more than 2-3 months), while 5% treatment eliminates the epithelial lining, at least focally, and resolves into complete occlusion within 1-2 months. This pattern of complete occlusion was seen in all 4 females that received 5% PF (+DMPA) and in 2/3 that received 5% PF (-DMPA). CONCLUSION: In a baboon model of transcervical permanent contraception, a single treatment with 5% PF resulted in complete tubal occlusion more reliably (85%) than 1% PF (38%). Cotreatment with DMPA may improve treatment results with 5% PF but requires additional study. IMPLICATIONS: A finding that a single transcervical treatment with 5% PF can occlude the fallopian tubes of baboon supports further study of this approach as a novel strategy for permanent contraception for women.