Laparoscopic-Facilitated Colonic Endoscopic Mucosal Resection and Endoscopic Submucosal Resection of Adenomas: Techniques to Avoid Segmental Colectomy

Abstract

A significant percentage of the colorectal neoplasms referred to colon and rectal surgeons for consideration for a segmental colectomy are benign sessile adenomas deemed “not amenable to colonoscopic removal” by the referring gastroenterologist. Up until the last decade, the treatment options for these lesions have been: (1) repeat colonoscopy, reassessment, and possible attempt at colonoscopic removal in the endoscopy suite, (2) formal transabdominal segmental colectomy, (3) transabdominal wedge-type colon wall excision, or (4) observation alone. Most surgeons, when faced with this situation, will perform a “cancer type” segmental colectomy because of the well-known possibility that the supposedly benign polyp may harbor an invasive cancer. Unfortunately, in a certain percentage, after doing such a resection, most often a right hemicolectomy, when the specimen is opened the surgeon is underwhelmed by the polyp in question. Most endoscopists worldwide are fearful of sessile polyps 2 cm or larger, especially those that are located in the cecum or right colon, since these latter polyps are far from the anus and because the wall of the right colon is thin and prone to perforation. Despite these challenges, over the past 30–40 years, endoscopists have developed endoscopic methods for dealing with larger benign sessile colonic polyps that allow colectomy to be avoided for many lesions that would otherwise be dealt with via segmental colectomy. Although initially introduced and developed for gastric biopsy, endoscopic mucosal resection (EMR) methods were later utilized to fully remove large gastric benign lesions, in piecemeal fashion. Later still, EMR methods were used as definitive treatment of superficial cancers invading into the superficial submucosa. As an offshoot of EMR, endoscopic submucosal dissection (ESD) methods were developed and introduced as a means of doing en bloc resection of large mucosal lesions, which permits a more thorough and useful pathologic evaluation in regard to completeness of resection and depth of invasion. In the past 20 years, EMR and ESD methods have been utilized for colorectal polyps. Again, the majority of the pioneers in this field were Japanese gastroenterologists. Because the colon wall is considerably thinner than the gastric wall, the enthusiasm for EMR in the colon is not as great as for the stomach due to fear of perforation. Thus, for large colonic polyps, ESD methods, although more difficult, may be safer and more logical. The literature attests to the fact that, in expert hands, polyps 4–6 cm in size can be safely excised in one piece via ESD. Despite these ESD successes, even the experts advise This paper was originally presented as part of the SSAT/SAGES Joint Symposium, The Endoscope as a Surgical Tool: Colorectal, at the SSAT 50th Annual Meeting, June 2009, in Chicago, Illinois. The other articles presented in the symposium were Qi Y, Stoddard D, and Monson JRT, Indications and Techniques of Transanal Endoscopic Microsurgery (TEMS), and Marks JH, TEM as a platform for NOTES.