Twelve retrospective observational/case-control studies were included in the review (n=16,566 patients; range 52 to 14,407). Overall study quality was considered moderate to poor; the absence of randomisation, blinding and allocation concealment were inherent to the included study designs and additional methodological flaws were present.
Laparoscopic appendectomy was associated with significantly smaller rates of surgical site infections than open appendectomy (OR 0.43, 95% CI 0.34 to 0.55; 11 studies), but this was associated with significant heterogeneity (Ι²=73%). This association remained, but heterogeneity was reduced (Ι²
=61%) when only studies at moderate risk of bias were analysed (OR 0.23, 95% CI 0.14 to 0.37).
Laparoscopic appendectomy was associated with a significantly longer operating time than open appendectomy (MD 12.80 minutes, 95% CI 8.35 to 17.25; four studies), but this was associated with significant heterogeneity (Ι²=86%). Exclusion of one study yielded similar results.
Laparoscopic appendectomy was associated with significantly shorter time to oral intake than open appendectomy (MD 0.8 days, 95% CI 0.5 to 1.15; three studies) and shorter length of hospital stay (MD 1.1 day, 95% CI 0.5 to 1.6; four studies). The analysis for length of hospital stay was associated with significant heterogeneity (Ι²=92%).
Three studies found that laparoscopic appendectomy patients used significantly less analgesia postoperatively than open appendectomy patients.
There was no significant difference between groups for intra-abdominal abscess complication rates.