Internal hernia after laparoscopic colorectal surgery: an under-reported potentially severe complication. A systematic review and meta-analysis.

BACKGROUND

Internal hernia following laparoscopic colorectal surgery is often under-reported. The aim of this review was to evaluate the occurrence rate of internal hernia following laparoscopic colorectal surgery, and to describe clinical presentation and management strategies.

METHODS

A comprehensive literature review was conducted including MEDLINE/Pubmed, EMBASE, SCOPUS, clinicaltrials.gov, and the Cochrane Database of Systematic Reviews through April 2018. The review was conducted according to MOOSE guidelines. Quality was appraised with the Methodological Index for Non-Randomized Studies (MINORS) tool. Meta-analysis was performed using a random effects model. Studies reporting data on internal hernia after laparoscopic colorectal surgery were included.

RESULTS

Ten observational studies with a total of 8453 patients were included. All included articles were non-comparative prospective or retrospective cohort studies with an average MINORS score of 8.3 (range 6-11). Summary estimate of proportion of patients developing internal hernia after laparoscopic colorectal resection was 0.5% (95% CI 0.3-0.8%). Heterogeneity was moderate (I 46%, p = 0.03) and study size (> 1000 vs. <1000 patients) was found to have a significant contribution to heterogeneity (p = 0.002). Thirty patients (90.9%) required surgery, with 5 non-fatal and 3 fatal postoperative complications. Quality of some studies was limited; some patients were followed up for less than 1 year; primary surgical procedures included different laparoscopic approaches.

CONCLUSIONS

Occurrence rate of internal hernia after laparoscopic colorectal resection is around 5 per 1000 patients. Small-sized studies are likely to overestimate the occurrence of internal hernia. Need for reoperation is high with a substantial risk of mortality.