Minimally invasive surgery for early lower GI cancer

Two technical developments in colorectal surgery—i.e. transanal endoscopic microsurgery (TEM) and laparoscopic surgery for colorectal disease—are now available for the treatment of early lower GI cancer. Benign lesions and early-stage tumours of the rectosigmoid are amenable for a transanal approach. Transanal endoscopic microsurgery is performed using a rectoscope 4 cm in diameter with a four-port insert. After installation of a pneumorectum, lesions up to 25 cm from the anal verge, including circumferential lesions, can be removed with a recurrence rate of 0–5% for adenomas, 3% for low-risk T1 carcinomas, and 8% for all carcinomas. Laparoscopic-assisted colonoscopic polypectomy, laparoscopic wedge resection or laparoscopic-assisted colostomy have a 67–100% success rate for avoiding a formal bowel resection for benign tumours that cannot be treated by colonoscopy alone. Early colonic cancer requires laparoscopic colectomy guided by preoperative colonoscopy or preoperative endoscopic tattooing for localisation of the affected segment.