Persistent spermatozoa after vasectomy: a survey of British urologists.

OBJECTIVES

To determine the rate of, and main indications for, repeat vasectomy in our department, and to assist in policy-making procedures by determining how urologists in England and Wales manage those men who show small but persistent quantities of motile or non-motile spermatozoa in their ejaculate after vasectomy.

SUBJECTS AND METHODS

A retrospective review of all of the vasectomies and repeat vasectomies performed by the Urology Department at Southmead Hospital during a 14-month period was undertaken to determine the rate of and indications for repeat vasectomy. Subsequently, every consultant urologist in England and Wales was canvassed with a questionnaire to determine whether they repeated vasectomy in the presence of persistent motile or non-motile sperms and if so, after what time interval. Any experience of pregnancies arising from these groups was also assessed, and any relevant comments invited.

RESULTS

The local review revealed that 5% of all vasectomies were repeated within 6-36 months. Of these, 87% were performed because of persistent sperms in post-vasectomy semen samples, the majority of which showed sperm concentrations of one in 50 to one in 100 high-power fields. A response of 56% was obtained to the questionnaire and of those responding, 23% never repeated a vasectomy where there were presistent non-motile sperms, but almost all urologists would eventually repeat vasectomy where motile sperms were present. The median interval between the first and second vasectomies was 6 months and 12 months for motile and non-motile sperm, respectively. Apart from those cases already published, there was little experience of pregnancy arising from men with persistently few motile or non-motile sperms.

CONCLUSIONS

The risk of pregnancy occurring in the presence of non-motile sperms was estimated to be less than the established risk of late recanalization, and this survey provides both logical and medico-legal support for issuing a 'special clearance' to men with few persistent non-motile sperm after vasectomy, providing the risks of pregnancy are properly discussed and documented. For motile sperm, however, there appears to be a stronger precedent for repeating the vasectomy. The technique used for post-vasectomy semen analysis was also an important consideration when determining any policy regarding such cases.