Effect of vasovasostomy on contralateral testicular damage associated withunilateral vasectomy in mature and immature Lewis rats

Objective: We sought to determine if laser-assisted vasovasostomy could rev erse the contsalateral histologic testicular changes associated with unilat eral vasectomy. Design: A prospective, randomized, blinded, controlled study. Setting: Animal microsurgical laboratory, St. John's Mercy Medical Center, St. Louis, Missouri. Patient(s): Twenty mature and 20 immature male Lewis r ats. Intervention(s): Ten mature and 10 immature male Lewis rats underwent unila teral vasectomy. At 5 months, testicular biopsy and laser-assisted vasovaso stomies were performed followed 2 months later by evaluation of vas patency and repeat testicular biopsy. Control animals consisted of 10 rats in each group, 5 that undervent sham operations and 5 that had halothane anesthesi a alone. Result(s): In the immature and mature groups unilateral vasectomy resulted in marked contralateral testicular damage in 30% (3 of 10) and 50% (5 of 10 ), respectively. Vas patency determined 2 months after vasovasostomy was 80 % (8 of 10) in the mature group and 89% (8 of 9) in the immature group. No animal that had contralateral testicular changes after vasectomy and a pate nt vas after vasovasostomy showed improvement in testicular histology. Conclusion(s): It appears that contralateral testicular damage associated w ith unilateral vasectomy is not improved 2 months after successful vasovaso stomy in mature or immature Lewis rats. (Fertil Steril(R) 2000;73: 238-41. (C) 2000 by American Society for Reproductive Medicine.)