Objectives. To assess the effect of irrigation of the distal vas deferens with sterile water at the time of vasectomy on sperm clearance. Is it possible to accelerate clearance and avoid the problem of lingering sperm?

Methods. Two hundred men undergoing vasectomy were randomized to receive either a standard vasectomy or vasectomy plus irrigation of each vas deferens with sterile water. The interval between vasectomy and the production of two azoospermic semen samples was recorded.

Results. Overall, 37 patients were excluded for failing to follow the postvasectomy protocol for semen analysis, leaving 87 in the control group and 76 who received vasal irrigation. No statistically significant differences existed between the two groups with regard to the mean time to clearance (26.4 weeks, control group versus 28.6 weeks, flush group), proportion clear at 16 weeks (29% versus 21%), or proportion with lingering sperm at 40 weeks (22% versus 26%).

Conclusions. Irrigation of the vas deferens with sterile water does not accelerate the clearance of spermatozoa after vasectomy. Men wishing to undergo vasectomy must be counseled about the possibility of lingering sperm.