Evers J L, Collins J A
Department of Obstetrics & Gynaecology, Academisch Ziekenhuis Maastricht, P.O. Box 5800, Maastricht, Netherlands, 6202 AZ.
Cochrane Database Syst Rev. 2004(3):CD000479. doi: 10.1002/14651858.CD000479.pub2.
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.
To evaluate the effect of varicocele treatment on pregnancy rate in subfertile couples.
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.
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.
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.
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.
精索静脉曲张是阴囊内扩张的血管网,通常发生在左侧,是由于精索静脉扩张所致。尽管精索静脉曲张导致男性不育且精索静脉结扎术可治愈不育这一概念已存在近五十年,但精索静脉曲张影响生育的机制尚未得到令人满意的解释,精索静脉结扎术恢复生育的机制也未明确。此外,有人质疑蔓状静脉丛扩张与生育能力受损之间是否存在因果关系。
评估精索静脉曲张治疗对不育夫妇妊娠率的影响。
我们检索了Cochrane月经紊乱与不育症研究组试验注册库(检索时间为2003年9月12日)、Cochrane对照试验中心注册库(2004年第1期《Cochrane图书馆》)、MEDLINE(1966年1月至2004年5月)、EMBASE(1985年1月至2004年5月)以及文章的参考文献列表。此外,我们手工检索了该领域22种专业期刊从创刊至2004年的所有内容。我们还检查了交叉参考文献、综述文章的参考文献,并联系了该领域的研究人员。
如果随机对照试验与所提出的临床问题相关、将妊娠率作为结局指标报告,并且报告了治疗组(精索内静脉手术结扎或放射栓塞)和未治疗组的数据,则纳入研究。
九项研究符合本综述的纳入标准。一项是先前发表研究的扩展研究(Nieschlag, 1995/1998),因此剩下八项研究进行分析(Nilsson, 1979;Breznik, 1993;Madgar, 1995;Yamamoto, 1996;Nieschlag, 1995/1998;Grasso, 2000;Unal, 2001;Krause, 2002)。所有八项研究仅纳入了有不育问题夫妇中的男性,一项研究(Madgar, 1995)排除了精子计数<500万/mL的男性,一项研究(Krause, 2002)排除了精子计数<200万/mL和/或进行性活动率<10%的男性,两项涉及临床精索静脉曲张的试验纳入了一些精液分析正常的男性(Nilsson, 1979;Breznik, 1993)。三项研究(Yamamoto, 1996;Grasso, 2000;Unal, 2001)专门针对仅患有亚临床精索静脉曲张的男性。两位作者独立筛选潜在相关试验。如有任何意见分歧,通过协商解决(本综述未出现分歧)。如果研究进行的比较超出上述规定范围,则排除在荟萃分析之外。
八项研究合并后的Peto比值比(OR)为1.10(95%可信区间0.73至1.68),表明在男性精索静脉曲张是唯一异常发现的不育夫妇中,精索静脉曲张治疗相对于期待治疗无益处。
没有证据表明,对其他方面原因不明的不育夫妇中的男性进行精索静脉曲张治疗能提高夫妇受孕的几率。