Sterility after vasectomy. (Letter)

The question raised is whether non-motile sperm dead or alive have a practical fertile potential when found in small numbers in vasectomize d males. Vital staining has shown that not all non-motile sperm are dead. However when the operation has been performed correctly so that the possibility of recanalization is minimized post-vasectomy counts may be unnecessary after 20 ejaculations have occured. The low numbers of sperm which may be present at this time are not effectively fertile and the association between oligospermia and infertility is generally accepted. Irrigation of the vas significantly reduces the number of positive counts found 3 months later. 2/3 of the individuals fail to show motile sperm as soon as 4 weeks after the operation. Those with excessive counts should not be considered infertile if a reasonable percentage of immotile sperm are viable. Vasectomy is a simple operation but it has limitations if long term surveillance is necessary before sterility is determined. A rational approach to postvasectomy management needs to be determined especially due to the medicolegal implications.