The Kinetics of Sperm Return and Late Failure Following Vasovasostomy or Vasoepididymostomy: A Systematic Review.

Vasovasostomy and vasoepididymostomy are technically challenging microsurgical reconstructive procedures necessary for men with obstructive azoospermia at the level of the vas deferens or epididymis. Patency rates following vasovasostomy or vasoepididymostomy have been widely described in the literature. However, few reports have discussed the timing of sperm return to the ejaculate after reconstruction as well as the proportion of men in whom late failure develops following vasovasostomy or vasoepididymostomy. Therefore, the objective of this article was to review the rates and predictors associated with late failure and the timing of sperm returning to the ejaculate after vasovasostomy and vasoepididymostomy. A literature search was performed using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines via the PubMed®/MEDLINE® database. We included relevant articles published in English in peer reviewed journals from 1960 to 2017 which reported outcomes regarding time to patency, time to late failure or the late failure rate after vasovasostomy or vasoepididymostomy. Macroscopic reconstructions were excluded from study. A total of 24 articles were included in the review. Mean time to patency after vasovasostomy and vasoepididymostomy ranged from 1.7 to 4.3 and 2.8 to 6.6 months, respectively. The late failure rate after microsurgical vasovasostomy and vasoepididymostomy ranged from 0% to 12% and 1% to 50%, respectively. Mean time to late failure after vasovasostomy and vasoepididymostomy ranged from 9.7 to 13.6 and 6 to 14.2 months, respectively. There was significant heterogeneity in the available data, limiting comparisons between series. Sperm returns to the ejaculate sooner in men who undergo vasovasostomy compared to vasoepididymostomy. Late failures are heterogeneously defined in the literature but they occur at a rate that is not insignificant. Thus, clinicians should discuss considerations for sperm cryopreservation.