Surgery or embolization for varicoceles in subfertile men New search for studies and content updated (conclusions changed)

Abstract

Abstract Background

A varicocele is a meshwork of distended blood vessels in the scrotum, usually left‐sided, due to dilatation of the spermatic vein. Although the concept that a varicocele causes male subfertility has been around for more than 50 years now, the mechanisms by which a varicocele would affect fertility have not yet been satisfactorily explained. Neither is there sufficient evidence to explain the mechanisms by which varicocelectomy would restore fertility. Furthermore, it has been questioned whether a causal relation exists at all between the distension of the pampiniform plexus (a network of many small veins found in the human male spermatic cord) and impairment of fertility.

Objectives

To evaluate the effect of varicocele treatment on live birth and pregnancy rate in subfertile couples where the male has a varicocele.

Search methods

We searched the Cochrane Menstrual Disorders and Subfertility Group Trials Register (12 September 2003 to January 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library Issue 1, 2012), MEDLINE (January 1966 to January 2012), EMBASE (January 1985 to January 2012), PsycINFO (to Week 1 2012) and reference lists of articles. In addition, we handsearched specialist journals in the field from their first issue until 2012. We also checked cross‐references, references from review articles and contacted researchers in the field.

Selection criteria

Randomised controlled trials (RCTs) were included if they were relevant to the clinical question posed. If they reported pregnancy rates or live birth rates as an outcome measure, and if they reported data in treated (surgical ligation or radiological embolization of the internal spermatic vein) compared to untreated or placebo groups. Two authors independently screened potentially relevant trials. Any differences of opinion were resolved by consensus (none occurred for this review).

Data collection and analysis

Ten studies met the inclusion criteria for the review. For one study we had only data from a published abstract. All ten studies only included men from couples with subfertility problems; one excluded men with sperm counts less than 5 million per mL and one excluded men with sperm counts less than 2 million per mL, with or without progressive motility of less than 10%. Two trials involving clinical varicoceles included some men with normal semen analysis. Three studies specifically addressed only men with subclinical varicoceles. Studies were excluded from meta‐analysis if they made comparisons other than those specified above.

Main results

The meta‐analysis included 894 men. No studies reported live birth. The combined fixed‐effect odds ratio (OR) of the 10 studies for the outcome of pregnancy was 1.47 (95% confidence interval (CI) 1.05 to 2.05, very low quality evidence), favouring the intervention. The number needed to treat for an additional beneficial outcome was 17, suggesting benefit of varicocele treatment over expectant management for pregnancy rate in subfertile couples in whom varicocele in the man was the only abnormal finding. Omission of the studies including men with normal semen analysis and subclinical varicocele, some of which had semen analysis improvement as the primary outcome rather than live birth or pregnancy rate, was the subject of a planned subgroup analysis. The outcome of the subgroup analysis (five studies) also favoured treatment, with a combined OR 2.39 (95% CI 1.56 to 3.66). The number needed to treat for an additional beneficial outcome was 7. The evidence was suggestive rather than conclusive, as the main analysis was subject to fairly high statistical heterogeneity (I2 = 67%) and findings were no longer significant when a random‐effects model was used or when analysis was restricted to higher quality studies.

Authors' conclusions

There is evidence suggesting that treatment of a varicocele in men from couples with otherwise unexplained subfertility may improve a couple's chance of pregnancy. However, findings are inconclusive as the quality of the available evidence is very low and more research is needed with live birth or pregnancy rate as the primary outcome.

Author(s)

Anja CJ Kroese, Natascha M de Lange, John Collins, Johannes LH Evers

Abstract

Plain language summary

Surgery or embolization for varicoceles in subfertile men

Varicocele is a dilatation (enlargement) of the veins along the spermatic cord (the cord suspending the testis) in the scrotum. Dilatation occurs when valves within the veins along the spermatic cord fail and allow retrograde blood flow, causing a backup of blood. The mechanisms by which varicocele might affect fertility have not yet been explained, and neither have the mechanisms by which surgical treatment of the varicocele might restore fertility. This review analysed 10 studies (894 participants) and found evidence (combined odds ratio was 1.47 (95% CI 1.05 to 2.05) to suggest an increase in pregnancy rates after varicocele treatment compared to no treatment in subfertile couples, in whom, apart from poor sperm quality, varicocele in the man was the only abnormal finding. This means that 17 men would need to be treated to achieve one additional pregnancy. However, findings were inconclusive as the quality of the available evidence was very low and more research is needed with live birth or pregnancy rate as the primary outcome.

Author(s)

Anja CJ Kroese, Natascha M de Lange, John Collins, Johannes LH Evers

Reviewer's Conclusions

Authors' conclusions

Implications for practice

Surgical or radiological treatment of varicocele in subfertile men with clinical varicocele and abnormal semen analysis may be of benefit, but the evidence is not conclusive. The value of surgical or radiological treatment in subfertile men with subclinical varicocele and normal semen analysis is disputable, as the number needed to treat to benefit was 17.

Implications for research

The ideal trial design would be to compare, in a randomised fashion, a sham operation with the actual procedure; any other design is potentially biased by the placebo effect of having had the operation performed; and surgery is a strong placebo indeed. However, for such a trial design it would be difficult to obtain ethical committee approval since it would put the control group at risk of surgical and anaesthetic complications without any possibility of benefit (Hargreave 1997). Since all studies included in the present review essentially considered invasive treatment, in none had the investigator, patient, or assessor been blinded to the procedure performed. However, the outcome measures of this review, live birth and pregnancy rate, were unambiguous. Therefore, apart from the placebo effect, no other negative factors of the lack of blinding were presumed to affect the conclusions drawn.

The studies included in the present review of varicocele treatment are heterogeneous. This indicates a need for a large, properly conducted RCT of varicocele treatment in men with varicocele and sperm defects, from couples with otherwise unexplained subfertility. The authors realise, however, that it will become increasingly difficult to conduct such a study, since the introduction of in vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI) in the fertility clinic will make many men reluctant to take the risk of being allocated to the no‐treatment arm of such a study, when at the same time a robust treatment of proven effectiveness is readily available in the form of IVF/ICSI. The issue will be further compounded by the fact that many couples tend to delay their first pregnancy nowadays, and are likely to feel that they have not much time left to spend on expectant management once they have decided, in their mid‐ to late thirties, to seek professional help for their fertility problem.

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