1. Clinical Research on NSV
Recent Findings
and
Programmatic Implications

2. 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
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3. 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Sources: Costello et al, Centers for Disease Control & Prevention, unpublished; Wang, Contraception; 2002 and Nazerali et al.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
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4. What is the Best Vas Occlusion Technique?
Recent results based on semen analysis:
Retrospective review
Clips - 7.1% (103/1453)
Cautery % (1/1165)
Prospective, non-comparative study
Ligation & excision alone % (25/217)
Sources: Labrecque et al. J Urol 2002; Barone et al. J Urol in press, 2003
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5. 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
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6. 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
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7. When Can Men Rely on Their Vasectomy for Contraception?
20 ejaculations 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%)
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Source: Barone et al, in press, 2003

8. 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
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9. 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
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