title: A randomized, controlled, multicenter contraceptive efficacy clinical trial of the intravas device, a nonocclusive surgical male sterilization.
abstract: Because of unavoidable complications of vasectomy, this study was undertaken to assess the efficacy and safety of male sterilization with a nonobstructive intravas device (IVD) implanted into the vas lumen by a mini-surgical method compared with no-scalpel vasectomy (NSV). IVDs were categorized into two types: IVD-B has a tail used for fixing to the vas deferens (fixed wing) whereas IVD-A does not. A multicenter prospective randomized controlled clinical trial was conducted in China. The study was comprised of 1459 male volunteers seeking vasectomy who were randomly assigned to the IVD-A (n = 487), IVD-B (n = 485) or NSV (n = 487) groups and underwent operation. Follow-up included visits at the 3 rd -6 th and 12 th postoperative months. The assessments of the subjects involved regular physical examinations (including general and andrological examinations) and semen analysis. The subjects' partners also underwent monitoring for pregnancy by monthly interviews regarding menstruation and if necessary, urine tests. There were no significant differences in pregnancy rates (0.65% for IVD-A, 0 for IVD-B and 0.21% for NSV) among the three groups (P > 0.05). The cumulative rates of complications at the 12 th postoperative month were zero, 0.9% and 1.7% in the three groups, respectively. In conclusion, IVD male sterilization exhibits a low risk of long-term adverse events and was found to be effective as a male sterilization method, similar to the NSV technique. IVD male sterilization is expected to be a novel contraceptive method.
authors.forename: Wen-Hong
authors.initials: WH
authors.lastname: Lu
authors.forename: Xiao-Wei
authors.initials: XW
authors.lastname: Liang
authors.forename: Yi-Qun
authors.initials: YQ
authors.lastname: Gu
authors.forename: Wei-Xiong
authors.initials: WX
authors.lastname: Wu
authors.forename: Li-Wei
authors.initials: LW
authors.lastname: Bo
authors.forename: Tian-Gui
authors.initials: TG
authors.lastname: Zheng
authors.affiliation: Key Laboratory of Male Reproductive Health, National Health and Family Planning Commission, National Research Institute for Family Planning and WHO Collaborating Centre for Research in Human Reproduction, Beijing, China.
authors.forename: Zhen-Wen
authors.initials: ZW
authors.lastname: Chen
mesh_terms: D000328:Adult; D002681:China; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D011446:Prospective Studies; D013076:Sperm Count; D013081:Sperm Motility; D013245:Sterilization, Reproductive / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D016896:Treatment Outcome; D014649:Vas Deferens / Q000601:surgery*; D014659:Vasectomy / Q000009:adverse effects; D055815:Young Adult