Clinical Research on NSV

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

3
Pregnancy Rates After Vasectomy
Sources Costello et al, Centers for Disease
Control Prevention, unpublished Wang,
Contraception 2002 and Nazerali et al.
Contraception, 2003
4
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
5
Vasectomy Failure and Recanalization Rates
Recanalization based on qualitative assessment by
3 masked reviewers Failure defined as gt 10
million sperm/mL at 12 weeks or later
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

7
When Can Men Rely on Their Vasectomy for
Contraception?
azoospermia
lt 3 million / mL
3-20 million/ml.
20 million / mL
Source Barone et al, in press, 2003
8
Severe Oligospermia at 12-14 Weeks and 20
Ejaculation After Vasectomy
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