Clinical Research on NSV Recent Findings and Programmatic Implications

Programmatic Implications of Clinical Research Findings New evidence on: pregnancy rates following vasectomy effectiveness of different occlusion methods when can men rely on their vasectomy for contraception cautery device reuse EngenderHealth

Pregnancy Rates After Vasectomy 5 years 9.5% 3 years 4.2% Nepal 1 years China 1.9% US Time after vasectomy Failure rate Location Sources: Costello et al, Centers for Disease Control & Prevention, unpublished; Wang, Contraception; 2002 and Nazerali et al. Contraception, 2003 EngenderHealth

What is the Best Vas Occlusion Technique? Recent results based on semen analysis: Retrospective review Clips - 7.1% (103/1453) Cautery - 0.09% (1/1165) Prospective, non-comparative study Ligation & excision alone - 11.5% (25/217) Sources: Labrecque et al. J Urol 2002; Barone et al. J Urol in press, 2003 EngenderHealth

Vasectomy Failure and Recanalization Rates Recanalization based on qualitative assessment by 3 masked reviewers Failure defined as > 10 million sperm/mL at 12 weeks or later EngenderHealth

When Can Men Rely on Their Vasectomy for Contraception? Ideal is semen analysis to confirm azoospermia (or severe oligospermia) Semen analysis unavailable or inaccessible in many low resource settings A common recommendation is after 12 weeks or 20 ejaculations EngenderHealth

When Can Men Rely on Their Vasectomy for Contraception? 20 ejaculations 12 weeks 100 90 80 70 60 50 40 30 20 10 azoospermia < 3 million / mL 3-20 million/ml. 20 million + / mL Vasectomy by ligation and excision alone…i.e. without fascial interposition Sperm concentrations indicating potential fertility (3 million sperm/ml or more) were more prevalent at 20 ejaculations postvasectomy (43/210; 20.5%) compared with 12 weeks (27/207; 13.0%) EngenderHealth Source: Barone et al, in press, 2003

Severe Oligospermia at 12-14 Weeks and 20 Ejaculation After Vasectomy Ligation and excision alone @ 14 weeks 82/100 men @ 20 ejaculations62.5/100 men Ligation and excision with FI @14 wks 91.2/100 men @ 20 ejaculations 73.4/100 men Cautery @ 12 weeks 95/100 men @ 20 ejaculations 77/100 men EngenderHealth

Conclusions… Vasectomy failures may be more common than generally thought, none the less vasectomy is an excellent method Ligation & excision without fascial interposition is an inferior occlusion method Cautery appears to be better than ligation & excision with fascial interposition 12 weeks is a better endpoint than 20 ejaculations for when men can rely on their vasectomy in setting where semen analysis is not practical EngenderHealth