Many epithelial tumors of the gastrointestinal tract develop as benign polyps before becoming malignant, as discussed in detail in earlier chapters of this book. These may be symptomatic or asymptomatic, pedunculated or sessile, and range in size from millimeters to many centimeters in diameter. If confined to the mucosa or superficial submucosa, they are nearly all amenable to endoscopic removal by one of a variety of polypectomy techniques, endoscopic mucosal resection (EMR), or endoscopic submucosal dissection (ESD).
The principles of endoscopic polypectomy have evolved to a standardized set of techniques since their introduction almost 40 years ago. EMR and ESD techniques continue to be developed as more recent innovations. Endoscopic resection aims to remove a tumor in its entirety for cure, for complete pathologic assessment, and to reduce or eradicate the risk of recurrence while maintaining the integrity of the wall of the gastrointestinal tract and avoiding procedure-related morbidity. Bleeding is the most common complication of polypectomy, occurring in 0.3–6.0% of cases. Postpolypectomy hemorrhage can occur immediately (within 12 hours) or can be delayed (up to 30 days) and is more likely to occur with larger polyps, sessile polyps, and polyps with thick stalks. Perforation, the most feared complication of polypectomy, remains rare but relatively unchanged in incidence since the introduction of these techniques. Perforation occurs in 1–2 per 1000 cases and is more likely to occur with piecemeal polypectomy of sessile polyps, cecal polyps, and with ESD.
Polypectomy, EMR, and ESD can all be accomplished in the sedated patient as there are no pain receptors in the mucosa and submucosa. The muscularis propria and serosa together with the mesentery are capable of generating pain sensation caused by mechanical forces (eg, stretching) and the thermal effects of electrosurgery. A wide range of accessories is now available for endoscopic polypectomy and the last decade has also seen improvements in electrosurgical generators with respect to ease of use, safety, and efficacy. All endoscopists should be equipped to remove small- to medium-sized sessile polyps and nearly all pedunculated polyps in the colon. Larger sessile polyps (>2 cm in diameter), very large pedunculated polyps in the colon, and polyps of all types in the esophagus, stomach, duodenum, and small bowel require additional expertise and technology and are usually referred to centers with experience in these areas. Such tertiary referral has been demonstrated to be safe and effective and to avoid the risk of unnecessary surgery. It is also cost-effective.
Removal of polyps throughout the gastrointestinal tract requires appropriate access with an endoscope bearing an instrumentation channel diameter adequate to take standard accessories. Most of these will pass through a 2.8-mm channel but some may require 3.2 mm or greater. Accessories include biopsy forceps, snares, injection needles, combination devices marrying more than one function in a single instrument, hemostatic clips and loops, bipolar and ...