Twenty-six studies (1,264 patients) were included in the review: three RCTS (211 patients, range 31 to 108 patients per trial), seven case-control studies (438 patients, range 44 to 89 patients per study) and 16 cohort studies (615 patients, range 11 to 126 patients per study). Duration of follow-up (where applicable) ranged from one to 58 months (overall mean 24 months). The overall quality of the studies was reported as being moderate. Mean quality scores were 2.7 (SE 1.2) for RCTs, 4.9 (SE 0.3) for cohort studies and 6.0 (SE 0.7) for the case-control studies.
For symptomatic outcomes (nine cohort studies, one case-control study), rates of success were 86.6% in the mesh group (mean duration of follow-up 27.7 months, SE 4.2) and 97% in the non-mesh group (mean duration of follow-up 15 months). For objective outcomes (three RCTs, 12 cohort studies, five case-control studies), rates of success were 85.4% in the mesh group and 73.7% in the non-mesh group (mean duration of follow-up in both groups 25.3 months, SE 4).
Where reported, mean rate of conversion from laparoscopic to open surgery was 0.8% in the mesh group and 2.8% in the non-mesh group. Intraoperative complications occurred slightly less in the mesh group (5.7%) than the non-mesh group (9.3%). No mortality was reported for the mesh group and a very low rate was reported for the non-mesh group (0.7%). Postoperative complications were almost equal between the mesh group (10.8%) and the non-mesh group (9.2%). Mean length of hospital stay was higher in the mesh group (mean 3.3 days, SE 0.4) compared with the non-mesh group (mean 2.6 days, SE 0.5). The operation duration was somewhat higher in the mesh group (mean 165.8 minutes, SE 10.2) than in the non-mesh group (mean 143.8 minutes, SE 9.5). Full results (including numbers of patients in each analysis) were reported in the review paper.