Evaluation of the contralateral inguinal ring in clinically unilateral inguinal hernia: a systematic review and meta-analysis

Abstract

Purpose: 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.

Conflict of interest statement

Declaration of conflict of interest:

PK declares no conflict of interest

HW declares no conflict of interest

JR declares no conflict of interest

KH declares no conflict of interest

CN declares no conflict of interest

Conflicts of Interest: None of the authors have a conflict of interest to disclose.

Figures

Figure 1

Flow diagram of search strategy.

Figure 2

Pooled incidence of Metachronous Hernia after open primary repair and expectant management.

Figure 3

Pooled incidence of CPP with laparoscopic examination of the contralateral inguinal canal.