title: The contraceptive efficacy of intravas injection of Vasalgel™ for adult male rhesus monkeys.
abstract: BACKGROUND
  Options for male contraception are limited. The purpose of this study was to use a nonhuman primate model to evaluate Vasalgel™, a high molecular weight polymer being developed as a contraceptive device for men.
  
  
  METHODS
  Sixteen adult male rhesus monkeys received intravas injections of Vasalgel, consisting of 25% styrene maleic acid in dimethyl sulfoxide. After a one-week recovery, males were returned to outdoor group housing, which included at least 3 and up to 9 intact, breeding females with a successful reproductive history.
  
  
  RESULTS
  Treated males have had no conceptions since Vasalgel injections. All males were housed with intact females for at least one breeding season and seven have been almost continually housed with females for 2 years. Complications were minor and included one incident of incorrect placement of Vasalgel into the vas deferens and the development of a sperm granuloma in one animal. Three unilateral vasectomies were performed, one was necessary for incorrect placement of Vasalgel, the other two were elective.
  
  
  CONCLUSIONS
  Intravas injection of Vasalgel in sexually mature adult male rhesus monkeys was effective in preventing conception in a free-living, group environment. Complications were few and similar to those associated with traditional vasectomy.
authors.affiliation: California National Primate Research, University of California, One Shields Ave, Davis, CA 95616 USA.
authors.forename: Angela
authors.initials: A
authors.lastname: Colagross-Schouten
authors.affiliation: California National Primate Research, University of California, One Shields Ave, Davis, CA 95616 USA.
authors.forename: Marie-Josee
authors.initials: MJ
authors.lastname: Lemoy
authors.affiliation: California National Primate Research, University of California, One Shields Ave, Davis, CA 95616 USA.
authors.forename: Rebekah I
authors.initials: RI
authors.lastname: Keesler
authors.affiliation: Parsemus Foundation, PO Box 2246, Berkeley, CA 94702 USA.
authors.forename: Elaine
authors.initials: E
authors.lastname: Lissner
authors.affiliation: California National Primate Research, University of California, One Shields Ave, Davis, CA 95616 USA.|Department of Obstetrics and Gynecology, University of California, Davis, CA 95616 USA.
authors.forename: Catherine A
authors.initials: CA
authors.lastname: VandeVoort
keywords: Colony management; Contraception; Fertility; Hydrogel; Macaca mulatta; Primate; Sterilization; Styrene maleic acid polymer; Vas deferens; Vasalgel; Vasectomy