Thirty-four studies (2,729 unique stoma closures) were included in the review: two RCTs, five prospective studies and 29 retrospective studies. The quality of included studies appeared to be variable (acknowledged by the authors). Median follow-up from closure was 36 months (range two weeks to 9.8 years), where reported.
Overall incidence of incisional hernia was 7% (range 0% to 48%). The reoperation rate of patients who developed an incisional hernia and needed a surgical repair was 51%. There was a lower risk of incisional hernia following reversal of ileostomy compared to colostomy (OR 0.28, 95% CI 0.12 to 0.65; Ι²=0%; six studies). A funnel plot suggested a low risk of publication bias. The imaging studies reported higher detection rate with computed tomography (CT) compared to ultrasound (19% versus 48%). When these studies (assessment for hernia was primary endpoint) were combined, a clinical hernia rate of 30% and a combined clinical and radiological hernia rate of 35% were found (three studies).
Differences in age, gender and body mass index (BMI) were not predictive factors for herniation. One study found that patients with concomitant illness such as diabetes, chronic obstructive pulmonary disease and hypertension were at greater risk of developing an incisional hernia.