title: Evaluation of the contralateral inguinal ring in clinically unilateral inguinal hernia: a systematic review and meta-analysis.
abstract: OBJECTIVE
  The management of the contralateral inguinal canal in children with clinical unilateral inguinal hernia is controversial. Our objective was to systematically review the literature regarding management of the contralateral inguinal canal.
  
  
  METHODS
  We searched MEDLINE, EMBASE, and Cochrane databases (1940-2011) using 'hernia' and 'inguinal' and either 'pediatric,' 'infant,' or 'child,' to identify studies of pediatric (age ≤21 years) patients with inguinal hernia. Among clinical unilateral hernia patients, we assessed the number of cases with contralateral patent processus (CPP) and incidence of subsequent clinical metachronous contralateral hernia (MCH). We evaluated three strategies for contralateral management: expectant management, laparoscopic evaluation or pre-operative ultrasound. Pooled estimates of MCH or CPP were generated with random effects by study when heterogeneity was found (I(2) > 50 %, or Cochrane's Q p ≥ 0.10).
  
  
  RESULTS
  We identified 2,477 non-duplicated studies, 129 of which met our inclusion criteria and had sufficient information for quantitative analysis. The pooled incidence of MCH after open unilateral repair was 7.3 % (95 % CI 6.5-8.1 %). Laparoscopic examination identified CPP in 30 % (95 % CI 26-34 %). Lower age was associated with higher incidence of CPP (p < 0.01). The incidence of MCH after a negative laparoscopic evaluation was 0.9 % (95 % CI 0.5-1.3 %). Significant heterogeneity was found in studies and pooled estimates should be interpreted with caution.
  
  
  CONCLUSIONS
  The literature suggests that laparoscopically identified CPP is a poor indicator of future contralateral hernia. Almost a third of patients will have a CPP, while less than one in 10 will develop MCH when managed expectantly. Performing contralateral hernia repair in patients with CPP results in overtreatment in roughly 2 out of 3 patients.
authors: Division of Urology, Children's Hospital Los Angeles, Institute of Urology, University of Southern California, 4650 Sunset Blvd., #114, Los Angeles, CA, 90027, USA, pkokorowski@chla.usc.edu.
authors: P J
authors: PJ
authors: Kokorowski
authors: H-H S
authors: HH
authors: Wang
authors: J C
authors: JC
authors: Routh
authors: K C
authors: KC
authors: Hubert
authors: C P
authors: CP
authors: Nelson
mesh_terms: D002648:Child; D006552:Hernia, Inguinal / Q000175:diagnosis* / Q000601:surgery*; D059685:Herniorrhaphy; D006801:Humans; D007264:Inguinal Canal / Q000601:surgery*; D010535:Laparoscopy; D019564:Unnecessary Procedures
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