Is azoospermia the appropriate standard for post-vasectomy semen analysis? Or an unachievable goal of best practice laboratory guidelines

The increasingly stringent laboratory-approach to diagnosing azoospermia for post-vasectomy semen analysis (PVSA) continues to be at odds with the simpler approach desired by clinicians. This study describes the analysis of 10 years of PVSA and discusses the outcome in relation to risk, cost and assesses whether more stringent procedures are required. PVSA was performed on 4788 patients initially using a 2-test strategy (16 and 20 weeks post-surgery), moving to 1 test during 2013-2014. Azoospermia was confirmed by the analysis of 10 µl of semen followed by 10 µl of centrifuged pellet. In total, there were 9260 tests with a median of 1.93 tests/patient and 18.7 weeks to clearance. Surgical failure occurred in 1.75%, falling to 1.1% between 2011 and 2016. There were no cases of unwanted pregnancy, recanalization or complaints although misdiagnosis was detected in 1 case as a result of failure to confirm patient identification. Azoospermia performed according to World Health Organization (WHO) guidelines is sufficiently robust to confirm success/failure of vasectomy. With uncertainty surrounding the diagnosis, efforts to improve detection of occasional non-motile sperm are futile, cost more and fail to reduce risk of inappropriate clearance. Misdiagnosis is more likely from patient identification error and mitigation may include reverting to the safety net of a 2-test strategy.