Local resection for early rectal tumours: Comparative study of transanal endoscopic microsurgery (TEM) versus posterior trans-sphincteric approach (Mason's operation)

OBJECTIVE: To compare local resection of early rectal tumours by transanal endoscopic microsurgery (TEM) and the conventional posterior trans-sphincteric approach (Mason's operation). METHODS: The study group comprised 31 consecutive patients with early rectal tumours (18 villous adenomas, 13 adenocarcinomas) who underwent TEM in Kwong Wah Hospital, Hong Kong. The control group consisted of 51 patients with early rectal tumours (27 villous adenomas, 24 adenocarcinomas) who underwent Mason's operation in Peking Union Medical College Hospital, Beijing. Outcome measures included morbidity and mortality, operation time, recurrence rate and postoperative pathological staging. RESULTS: Age, sex and pathological staging were similar in the two groups. The tumour size, operation time and blood loss were similar. The median distance from the anal verge was significantly higher in the TEM group (TEM/Mason = 8.0/6.4 cm, p = 0.042). The postoperative resumption of food intake (TEM/Mason = 1/5 days, p = 0.002) and the median hospital stay (TEM/Mason = 4/10 days, p = 0.005) were significantly shorter in the TEM group. Analgesic intake was significantly less in the TEM group (TEM/Mason = 0/100 mg, p = 0.0003). There was no operation-related mortality and the resection margins were clear in both groups. Two patients (3.9%) in the Mason's group developed postoperative wound infection, and two patients (3.9%) developed faecal fistulae. There was one secondary haemorrhage in the TEM group that required injection sclerotherapy. On median follow-up of 23 months, there was no tumour recurrence in the TEM group, whereas two patients (3.9%) in the Mason's group experienced recurrence during a median follow-up of 30 months. CONCLUSION: TEM is as effective as the conventional posterior trans-sphincteric approach (Mason's operation) for local curative resection of early rectal tumours. TEM is less invasive, with shorter hospital stay and fewer complications than conventional Mason's operation.