Fig. 14

Schematic illustration showing different surgical techniques used to resect rectal cancer, including their post-operative appearance on MRI. With TAMIS and TEM (a), a full-thickness resection of the tumour and the rectal wall results in a focal wall defect and surrounding fibrotic changes on post-operative MRI (white arrowheads). After a low anterior resection (b), patients typically receive a ‘side-to-end’ anastomosis where the sidewall of the proximal colon loop is anastomosed to the end of the rectum stump, creating a small blind-ending loop of the colon that can also be recognised on post-operative MRI (black arrow). After an abdominoperineal resection, the rectum and anal canal are no longer in situ, and the patient receives a permanent colostomy. In this case, the post-operative defect in the pelvis and pelvic floor was reconstructed with a myocutaneous rectus muscle flap (white arrows)