Microscopic visualization of intravasal spermatozoa is positively associated with patency after bilateral microsurgical vasovasostomy

We evaluated pre-operative and intraoperative factors associated with successful patency following bilateral microsurgical vasovasostomy (VV). We retrospectively reviewed the charts of 1331 men who underwent bilateral VV by two surgeons between 2006 and 2013. Vasal fluid was examined intraoperatively for gross quality (i.e., clear or opaque and creamy/thick) and for the presence of spermatozoa on microscopy (i.e., whole spermatozoa, sperm fragments, or azoospermia). Post-operative patency was assessed by semen analysis or patient report of conception. Perioperative factors were explored using descriptive statistics and examined in logistic regression models for associations with post-operative patency. The median age at VV was 39 years [interquartile range (IQR): 35-44] and the median obstructive interval (OI) was 7 years (IQR: 4-11). Overall, 1307 patients achieved post-operative patency (98%) while 24 remained obstructed (2%). Among those who became patent, 410 reported conception. After adjustment for potential confounders, only microscopic examination of the intravasal fluid for the presence of spermatozoa (bilateral or unilateral whole spermatozoa vs. sperm parts/azoospermia) at the time of VV was significantly associated with post-operative patency with an odds ratio (OR) of 14.2 (95% CI: 5.8-34.9; p = <1 × 10(-8) ). Identification of bilateral or unilateral sperm fragments vs. azoospermia was also associated with increased odds of post-operative patency with an OR of 3.5 (95% CI: 0.9-13.6; p = 0.08). There was no statistically significant association between age at VV, OI, presence of granuloma, gross fluid quality, or surgeon and post-operative patency after controlling for potential confounders. Identification of whole spermatozoa in the vasal fluid at the time of VV was positively associated with post-operative patency. Our findings stress the need for intraoperative microscopy to aid in post-operative patient counseling.