TH8.1 Radiological incidence of donor-site incisional hernia and parastomal hernia after Vertical Rectus Abdominus Myocutaneous Flap-based reconstruction following colorectal surgery

Abstract Aims The vertical rectus abdominis myocutaneous (VRAM) flap is commonly used to reconstruct perineal defects for low rectal and anal cancer. The incidence of midline incisional hernias after VRAM reconstruction varies from 3.6% when detected clinically to up to 50% when detected radiologically. The aims of this study is to accurately determine the radiological incidence of donor-site incisional and parastomal hernia following VRAM reconstruction. Methods Retrospective cohort study of patients undergoing colorectal surgery requiring VRAM reconstruction over 10 years. Data were collected on patient demographics, indication for surgery and surgical procedure including details of any hernia repair. Images from surveillance CTs were reviewed for presence and size of midline incisional and/or parastomal hernias. Parastomal hernias were classified based on the European Hernia Society (EHS) classification. Results 173 patients were included in the analysis. The median age was 67 years (range 29 – 88 years) and median length of follow up was 49 months (IQR 24.3 – 71.0 months). The overall radiological incidence of incisional hernia was 27.6%. The radiological incidence of donor-site incisional hernia after VRAM at 1, 2 and 5 years was 16.8%, 25.2% and 18.5%. The parastomal hernia incidence at 1, 2 and 5 years was 37.9%, 44.1% and 29.8% (48.6% overall). Conclusions The majority of patients who develop donor-site incisional hernia and parastomal herniation following VRAM tend to do so within the first two years. Although the use of CT imaging improves the diagnosis of donor-site incisional and parastomal hernias, the clinical significance of this is unknown.