Parastomal hernias causing symptoms or requiring surgical repair after colorectal cancer surgery—a national population-based cohort study

Purpose Parastomal hernia is a complication with high morbidity that affects the patient’s quality of life. The aim of this study was to assess the cumulative incidence of parastomal hernia in patients who have undergone colorectal cancer surgery and to identify potential risk factors that could predispose to the development of this type of hernia in a large population-based cohort over a long follow-up period. Methods The Swedish Colorectal Cancer Registry and the National Patient Register were used to collect study cohort data between January 2007 and September 2013. All patients undergoing colorectal cancer surgery including a permanent stoma were included in the study group. Results A total of 39,984 patients were registered during the study period. Of these, 7649 received a permanent stoma. Multivariate proportional hazard analysis, based on 6329 patients for whom all covariates could be retrieved, showed that the only independent risk factor for developing a parastomal hernia was BMI ≥ 30 (HR 1.49; 95% CI 1.02–2.17; p < 0.037). A slightly elevated hazard ratio was found for preoperative radiotherapy (HR 1.36; 95% CI 0.96–1.91; p < 0.070). The cumulative incidence of patients diagnosed or surgically treated for parastomal hernia over a follow-up period of 5 years was 7.7% (95% CI 6.1–9.2%). Conclusions The cumulative incidence of parastomal hernia causing symptoms or requiring surgery after 5 years was at least 7.7%. Obesity increases the risk of developing parastomal hernia.