Review of Surgical Resection for Intramucosal Colorectal Neoplasms

Abstract

Background: Intramucosal colorectal neoplasms such as adenoma and carcinoma in situ have no risk for metastasis. Therefore they are curable by local treatment without lymph node dissection. Recent advances in the technique of endoscopic resention (ER) which is generally considered to be less invasive treatment than surgery has made it possible to resect even big tumors which had been unresectable endoscopically previously. Aim: For the purpose of reducing unnecessarily-invasive surgical treatment, we retrospectively analyzed patients that underwent surgery for colorectal adenoma and carcinoma in situ. Patients and Methods: Patients who underwent surgical resection (SR) for pathologically proven colorectal adenoma and carcinoma in situ in our department between 1991 and 2007 were studied. Transanal resection cases were excluded. Patients' record were retrospectively reviewed and indications for surgical resection were classified as follows; (A) Technical too difficult - Tumor size or location made ER impossible, (B) Overestimation of invasion depth - Endoscopic findings or non-lifting sign suggested submucosal (SM) invasion, and (C) Others. Results: Total 71 cases were studied. The reason for SR in 29 cases was (A) Technical too difficult for ER, and that in 33 cases was (B) Overestimation of invasion depth. In group (A), tumor size in 20 and location in 9 cases were main reasons for SR. After introduction of endoscopic submucosal dissection (ESD) technique, the minimum size of tumor which needed SR was 63mm. There were 11 cases in which tumor size was 60mm or less before the development of ESD in group (A). In group (B), 27 cases underwent SR due to endoscopic findings suggestive of submucosal invasion and other 6 cases due to non-lifting sign. Major complicaitons of surgery which needed laparotomy occured in 5 cases (7.0%). Conclusion: More than 60% of patients (11 cases with tumor <60mm in size in group (A) + all group (B) 33 cases = 44 cases) who underwent SR for early tumors could potentially have undergone ER. Endoscopic findings and non-lifting sign may overestimate invasion depth of tumors. As surgery is sometimes accompanied by severe complications, a trial ER with ESD technique should be considered where required.