Vasectomy occlusion techniques for male sterilization

Surgeons use a variety of surgical techniques for occluding the vas, which suggests that no single method has been shown to be superior to others. Fascial interposition – which can be used with most occlusion techniques – when performed in combination with ligation and excision, reduces the risk of occlusion failure without increasing the cost or side-effects of the procedure.

RHL Commentary by Xiaozhang L

1. EVIDENCE SUMMARY

This review (1) aimed to compare the effectiveness, safety, acceptability and costs of vasectomy techniques for male sterilization. Six randomized controlled trials met the inclusion criteria for the review. One trial compared vas occlusion with clips versus a conventional vasectomy technique. Three trials examined vas irrigation with sterile water versus no irrigation or irrigation with spermicidal euflavine. None of the trials found a difference between the groups for time to azoospermia except one trial, which reported that the euflavine group had lower median number of ejaculations to azoospermia than the water irrigation group. One high-quality trial compared vasectomy with fascial interposition versus vasectomy without fascial interposition. Fascial interposition was less likely to end in vasectomy failure at 34 weeks [odds ratio (OR) 0.42; 95% confidence interval (CI) 0.26–0.70]. Although fascial interposition was associated with some increased surgical difficulties, adverse events did not differ between the two groups. One trial compared an intra-vas device versus the no-scalpel method. The intra-vas device group was reported to be less likely to achieve azoospermia at 12 months (OR 0.17; 95% CI 0.08–0.36) than the no-scalpel group, but men in the intra-vas device group were more likely to be satisfied with the procedure. No conclusion could be reached regarding vas occlusion with clips or vasectomy with vas irrigation because the available studies were of poor quality and statistically underpowered. Fascial interposition improved vasectomy success.

2. RELEVANCE TO UNDER-RESOURCED SETTINGS

2.1. Magnitude of the problem

Vasectomy is a simple, safe, effective, low-cost method of permanent contraception. It is an important component of a balanced contraceptive method mix. Worldwide an estimated 31 million couples are currently relying on vasectomy for contraception (2).

A WHO publication (3) states that, "vasectomy is highly effective when the procedure is properly performed and when the man waits for 3 months after the vasectomy before having unprotected intercourse". Pregnancy rates associated with vasectomy are reported in the range of 0–2 per 100 operations, with most studies reporting failure rates of less than 1% (4). Recent studies, however, suggest that, for vasectomies performed using ligation and excision, failures are more common than previously thought (5). Method failure may due to client behaviour (having unprotected intercourse during the waiting period) or due to technical failure of the procedure.

Spontaneous recanalization of the vas is the most common cause of failure of the technique. Recanalization usually occurs when sperm granulomas forms at the vasectomy site. Multiple interconnecting epithelialized channels may develop within the granulomas and reconnect the two cut ends of the vas, re-establishing patience. Recanalization can occur soon after a vasectomy or may take several years. Early recanalization is identified by post-vasectomy sperm counts. The vasectomized individual may at first be azoospermic or may have a low sperm count, but the sperm count increases rapidly afterwards. Late recanalization is usually discovered only after a pregnancy occurs in the female partner. The pregnancy rate due to late recanalization is approximately 1 in 2000 (4). It is possible that vasectomy failures are underestimated as some women conceal and terminate pregnancies resulting from vasectomy failure. In a study of men seeking reversal of vasectomy, nearly 10% of pre-reversal ejaculates were found to contain sperm, suggesting potential method failure (6).

A variety of surgical techniques for occluding the vas have been developed over the years: ligation, excision, clips, cauterization, open-ended, fold-back, fascia interposition, irrigation, etc. Surgeons may use one or a combination of these in a single vasectomy. This heterogeneity in practice reflects the lack of evidence for superiority of any one occlusion technique over others in terms of increased effectiveness of vasectomy procedure and reduced complications.

2.2. Applicability of the results

Greater surgical experience is associated with higher rates of vasectomy success. However, one study (7) has shown that the techniques of vas occlusion used are at least as important. Simple ligation of the vas with suture material and excision of a small vas segment is believed to be the most common vasectomy occlusion technique performed in the under-resourced settings. Although it is the simplest method, ligation and excision is considered to be the least effective method (8). Adding fascial interposition to ligation and excision can significantly improve the effectiveness of vasectomy (9).

Fascial interposition, when performed in combination with ligation and excision, reduces the risk of occlusion failure without increasing the cost or side-effects of the procedure. Fascial interposition can be performed with most occlusion techniques, but the performance of fascial interposition requires additional surgical skills and appropriate hands-on training and practice are essential for developing proficiency.

2.3. Implementation of the intervention

Fascial interposition is promoted as a way of reducing vasectomy failure rates in under-resourced settings where ligation and excision is the primary occlusion technique used. The addition of fascial interposition to ligation and excision, although widely known, is not performed as widely, even in countries where fascial interposition has been included in the national standards of practice as a mandatory or optional step (10, 11). Insufficient surgical skills and time needed to perform the technique are the main reasons reported for not performing fascial interposition.

Simple ligation and excision or clips should not be used alone owing to their higher failure rates. Flushing the distal vas deferens with saline or sterile water during vasectomy may decrease the postoperative sperm count but it does not reduce failure rates or time to clearance, and there is no spermatotoxic chemical irrigant for this indication that has been approved by the United States Food and Drug Administration.

As pregnancy after vasectomy may have serious personal and medico-legal consequences, men should be always informed about the small possibility of vasectomy failure and that pregnancy can occur even several year after vasectomy.

3. RESEARCH

Clear evidence is available that fascial interposition improves vasectomy effectiveness. However, further methodologically sound randomized controlled trials of different occlusion methods (including fascial interposition, thermal- or electrocautery, chemical occlusion, open-ended vas, irrigation with chemical agent, or combinations of these methods, with longer follow-up times) are required to find the best occlusion method for vasectomy in under-resourced settings in terms of the effectiveness, safety, acceptability and cost. Long-term effectiveness studies with standardized follow-up protocols and high follow-up rates are needed to document: (i) long-term failure rates of vasectomy for different techniques of vas occlusion; and (ii) which occlusion technique is more effective than others in decreasing the risk of chronic pain or discomfort in the scrotum or testicles. Cross-sectional studies in men with vasectomies of up to 10 years' duration would also be useful to document the long-term efficacy of the method.

References

  • Cook LAA, Van Vliet HHAAM, Lopez LM, Pun A, Gallo MF. Vasectomy occlusion techniques for male sterilization. Cochrane Database of Systematic Reviews 2006; Issue 4. Art. No.: CD003991; DOI: 10.1002/14651858.
  • World Contraceptive Use 2007. New York: Department of Economic and Social Affairs, Population Division, United Nations, 2007.
  • Selected practice recommendations for contraceptive use. Second edition. Geneva: World Health Organization, 2004
  • Royal College of Obstetricians and Gynaecologists. Male and female sterilization: evidence-based guideline No. 4. London: RCOG Press, 2004
  • Nazerali H, Thapa S, Hays M, Pathak LR, Pandey KR, Sokal DC. Vasectomy effectiveness in Nepal: a retrospective study. Contraception 2003;67:397-401.
  • Lemack GE, Goldstein M. Presence of sperm in the pre-vasectomy reversal semen analysis: incidence and implications. The Journal of Urology 1996;155:167-169
  • Sokal D, Irsula B, Hays M, Chen-Mok M, Barone MA. Vasectomy by ligation and excision, with or without fascial interposition: a randomized controlled trial. BMC Medicine 2004;2:6
  • Labrecque M, Dufresne C, Barone MA, Saint-Hilaire K: Vasectomy surgical techniques: a systematic review. BMC Med 2004;2:21.
  • Sokal D, Irsula B, Hays M, Chen-Mok M, Barone MA; Investigator Study Group. Vasectomy by ligation and excision, with or without fascial interposition: a randomized trial. BMC Medicine 2004;2:6
  • Chinese Medical Association. Clinical guideline for family planning. Beijing, People’s Army Medical Press, 2004.
  • Labrecque M, Pile J, Sokal D, Kaza RC, Rahman M, Bodh SS, et al. Vasectomy surgical techniques in South and South East Asia. BMC Urology 2005;5:10

This document should be cited as: Xiaozhang L. Vasectomy occlusion techniques for male sterilization: RHL commentary (last revised: 1 September 2008). The WHO Reproductive Health Library; Geneva: World Health Organization.

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