Surgery or embolisation for varicocele in subfertile men

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 varicocele causes, and varicocelectomy cures, male subfertility has been around for almost fifty years, the mechanisms by which varicocele would affect fertility have not yet been satisfactorily explained, and neither have 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 and impairment of fertility.

Objectives: To evaluate the effect of varicocele treatment on pregnancy rate in subfertile couples.

Search strategy: We searched the Cochrane Menstrual Disorders and Subfertility Group trials register (searched 12 Sept 2003), the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 1, 2004), MEDLINE (January 1966 to May 2004), EMBASE (January 1985 to May 2004) and reference lists of articles. In addition, we hand searched 22 specialist journals in the field from their first issue until 2004. We also checked cross references, references from review articles, and contacted researchers in the field.

Selection criteria: RCTs were included if they were relevant to the clinical question posed, if they reported pregnancy rates as an outcome measure, and if they reported data in treated (surgical ligation or radiological embolization of the internal spermatic vein) and untreated groups.

Data collection and analysis: Nine studies met the inclusion criteria for this review. One was an extension of a previously published study (Nieschlag 1995/1998), which left eight studies for analysis (Nilsson 1979; Breznik 1993; Madgar 1995; Yamamoto 1996; Nieschlag 1995/1998; Grasso 2000; Unal 2001; Krause 2002). All eight only included men from couples with subfertility problems, one (Madgar 1995) excluded men with sperm counts <5 mill/mL, one (Krause 2002) men with sperm counts <2 mill/mL and/or progressive motility <10%, two trials involving clinical varicoceles included some men with normal semen analysis (Nilsson 1979; Breznik 1993). Three studies (Yamamoto 1996; Grasso 2000; Unal 2001) specifically addressed only men with subclinical varicoceles. Two authors independently screened potentially relevant trials. Any differences of opinion were resolved by consensus (none occurred for this review). Studies were excluded from meta-analysis if they made comparisons other than those specified above.

Main results: The combined Peto odds ratio (OR) of the eight studies is 1.10 (95%CI 0.73 to 1.68), indicating no benefit of varicocele treatment over expectant management in subfertility couples in whom varicocele in the man is the only abnormal finding.

Reviewers' conclusions: There is no evidence that treatment of varicocele in men from couples with otherwise unexplained subfertility improves the couple's chance of conception.