Comparison of puncture versus vasotomy techniques for vasography in an animal model

We determine the adverse effects of 2 different techniques of vasography in an animal model.

Unilateral vasography was performed by a direct puncture technique with a lymphangiogram needle or through a partial thickness vasostomy technique in 2 groups of 10 adults Lewis rats using nonionic contrast medium mixed with methylene blue. Each rat had a contralateral vasectomy. A complete vasogram was confirmed by visualization of colored dye in the bladder. An additional group of 5 animals with unilateral vasectomy alone served as controls. The adverse effects of these 2 techniques were assessed by performing mating studies at 2 and 4 months after vasography. In vitro flow through the vas deferens, sperm granuloma formation and histology of the vas deferens at the vasography site were evaluated at sacrifice 5 months after vasography.

The fertility of the 3 groups, as measured by the mean number of uterine implantation sites, was not significantly different at the 2 and 4-month breeding periods. In addition, we observed no significant decrease in the fertility of the 3 groups with time. Complete vasal obstruction was noted at sacrifice in 2 rats (20%) in the vasostomy group and none in the puncture or control group (p = 0.476). The mean in vitro flow rates through the vasa of the puncture and vasostomy vasography groups were significantly lower than those in controls (p < 0.05) but not different from each other. The sperm granuloma formation rate was similar among the 3 groups.

Our results demonstrate that both vasography techniques have a measurable adverse effect on vasal flow rates and a potential adverse effect on fertility. The direct puncture method had a slightly lower complication rate than the partial thickness vasostomy method and it may be the preferable technique for the inexperienced microsurgeon.