Thermal energy can be applied to endoscopic forceps at the time of polypectomy or biopsy. Using the same principles and techniques described above for “cold” polypectomy/biopsy , monopolar electrocautery can be applied to enhance hemostasis and thermal destruction of the remaining margin of resected tissue. The theoretical benefit of this polypectomy technique has never been definitively proven. Additionally, the quality of the resected specimen can be degraded by cautery artifact, making histologic assessment by the pathologist difficult [14]. If polypectomy by forceps is thought to be appropriate given the size of the polyp, the authors recommend using a jumbo size forceps. Patients usually have a grounding pad applied to the mid-thigh before the procedure begins or when the decision is made to proceed with hot forceps polypectomy.

The injection of liquid into the submucosal plane beneath a polyp may aide in adequate and complete endoscopic polyp excision and is essential to the techniques of endoscopic mucosal resection (EMR ) and endoscopic submucosal dissection (ESD) . Submucosal “lifting” of the target lesion off of the deep submucosa and muscularis propria is thought to minimize transmural damage to the bowel wall and thus perforation. Further, this may also allow for more complete adenomatous tissue removal and minimize local recurrence. The injectate is delivered endoscopically via a flexible needle, which is passed through the working channel of the colonoscope (Fig. 9.2 and Video 9.2).

Lesions that do not lift appropriately despite injection may indicate invasion of the submucosa or muscularis propria by an invasive cancer focus within the lesion. In the case of prior attempts at polypectomy, the resultant fibrosis and scarring within the adenomatous polyp may also prevent adequate lifting. Thought must be given to endoscopic attempts at polypectomy of lesions that do not lift appropriately after submucosal injection or lesions that have an ulcerated component. Various substances are currently used for submucosal injection. The cheapest and most readily available is normal saline. Other commercially available injectates are also used, including glycerol, hyaluronic acid, succinylated gelatin, and hydroxyethyl starch (Hetastarch). Colored compounds such as methylene blue, indigo carmine, or dilute India ink can also be used both for submucosal lifting of the lesion and tattooing (Video 9.3) for future site identification.

While normal saline is the cheapest and most readily available substance for this purpose, use is limited to procedures for which prolonged submucosal lift is not needed. Normal saline rapid clearance from the submucosal plane makes it unsuitable for procedures such as EMR or ESD. A recently presented meta-analysis demonstrated higher rates of en bloc resection and lower rates of residual tissue remaining using a viscous solution versus normal saline [15]. Another recent meta-analysis comparing various solutions to normal saline demonstrated equivocal results, likely due to a lack of standardized injectates between the individual randomized trials [16].

In summary, submucosal injection with normal saline or other solution should result in adequate lift of the adenomatous polyp to facilitate endoscopic polypectomy. Lesions that do not lift adequately with appropriate injection technique may be indicative of invasion from an occult cancer or excessive fibrosis from prior attempts at polypectomy or biopsy.

The availability of endoscopic clips has increased in recent years. Both through-the-scope and over-the-scope devices are commercially available to endoscopists for use during colonoscopy (Fig. 9.3, Video 9.4). Reported uses include rendering polypectomy sites hemostatic, closure of colonic perforations, and mucosal approximation after EMR or ESD [17]. Studying mucosal healing after advanced polypectomy, 28 patients were randomly assigned to clip closure of the polypectomy site versus leaving the wounds open. At 4 weeks, the patients who underwent clip closure had a significantly higher rate of mucosal healing than those who were not closed [17]. While the clinical significance of this is unclear, endoscopists should become facile at the use of endoscopic clip placement, should the need arise.

For lesions too large for endoscopic forceps, a snare may be useful for polypectomy (Fig. 9.4 and Video 9.5). Endoscopic snares are available in a variety of configurations and sizes, and one can be chosen based on the anatomy of the lesion to be removed. Shape, size, and morphology of the polyp often will influence which type of snare is best suited for the application. Given the size of the lesion, it may also be difficult to retrieve a polyp from the lumen of the bowel once it has been resected. Large lesions often cannot be suctioned through the colonoscope for fear they become trapped and lost. Simply grasping the lesion with the snare and removing it by withdrawing the colonoscope may not be feasible if the polyp is in the proximal colon. Additional endoscopic devices such as through-the-scope baskets and nets may be used for this purpose to secure the lesion as the colonoscope is withdrawn.