Purpose: We evaluated the efficacy and mechanism of failure in a small case series of VasClip vasectomies.
Materials and methods: Between September 2003 and March 2004, 8 patients underwent elective vasectomy using the VasClip ligation band. Microscopic semen analysis was done a minimum of 4 weeks postoperatively and after at least 15 ejaculations. The number of sperm and motility were quantified in 15 or more high power fields. Successful vasectomy was defined as 2 consecutive postoperative unspun semen analyses containing no sperm. Patients with failed vasectomy underwent bilateral surgical removal of the vas deferens segments containing the ligation band for gross and histological analysis.
Results: Six of 8 patients (75%) were deemed azoospermic after 2 semen analyses at a mean followup of 7 and 11 weeks postoperatively, respectively. Two of 8 patients (25%) had semen analyses containing multiple motile sperm after vasectomy. In the 2 failed cases 1 side was patent, as demonstrated by vasal cannulation and irrigation with dilute methylene blue despite a well positioned, intact and secure ligation band. Histological analysis showed extravasation and sperm granuloma on the patent side.
Conclusions: The VasClip was found to fail at an unexpectedly high rate. Pathological analysis suggests sperm extravasation and fistula tract formation as the mechanism. One failure resulted in an unwanted pregnancy, which demonstrates the need for patient counseling regarding postoperative followup.