Blockade of tubal patency following transcervical administration of polidocanol foam: initial studies in rhesus macaques

ObjectiveTo demonstrate the feasibility of polidocanol foam (PF) as a nonsurgical method of female permanent contraception using a nonhuman primate model.Study DesignFour groups of adult female rhesus macaques underwent either transcervical treatment with 5% PF directly into the uterine cavity, treatment with inert (methylcellulose, MF) foam or no treatment followed by removal of the reproductive tract for histologic evaluation. Untreated animals were included in Group 1 (n= 3). Group 2 animals (n= 4) were treated once with MF. Group 3 (n= 7) received a single, and Group 4 (n= 5) received multiple monthly treatments with PF; in these 2 groups, baseline tubal patency was assessed either laparoscopically by chromopertubation (CP) or by hysterosalpingography.ResultsGroup 1 (untreated) and Group 2 (MF) animals had normal tubal histology. In contrast, Group 3 and 4 females treated with PF showed evidence of tubal damage. In Group 4, bilateral tubal blockade was noted on CP after two (n= 2) or three (n= 3) treatments. Histologic analysis confirmed complete tubal occlusion (loss of epithelium, fibrosis) in three of these animals, and one showed significant tubal damage localized to the intramural segment. Nontarget (cervix, vagina, endometrium, ovary) reproductive tissues were unaffected. While similar tubal changes were observed after a single treatment (Group 3), endometrial hemorrhage was also noted as an acute change.ConclusionPF is a promising candidate agent for nonsurgical permanent female contraception. The histologic features of PF occlusion are confined to the intramural portion of the tube.ImplicationsThis study in rhesus macaques supports further development of transcervical administration of PF as a nonsurgical approach to permanent contraception. A nonsurgical method could reduce risks and costs associated with surgical female sterilization and increase access to permanent contraception.