Management of colonic polyps: an advancing discipline

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Colonoscopy with polypectomy is moderately effective in reducing the incidence and mortality of colorectal cancer.1 Colonic polyps vary in size, morphology and risk of malignant transformation and thus polypectomy technique and surveillance recommendations are tailored accordingly. Over 90% of polyps encountered at colonoscopy are <10 mm in size, do not contain advanced pathology4 and are readily removed by conventional snare polypectomy. These may be hyperplastic polyps, adenomas or sessile serrated polyps (SSPs) and are most commonly of the Paris type 0‐ls, 0‐lla or 0‐lp.7 Approximately 5% of adenomatous polyps are large lateral spreading lesions (LSLs),8 which require advanced resection techniques such as endoscopic mucosal resection (EMR) or endoscopic sub‐mucosal dissection.
Diminutive polyps ≤5 mm are found most commonly in the rectum and distal sigmoid colon and although up to 51% may be adenomas, they rarely contain advanced pathology.4 Optical diagnosis of diminutive polyps has several attractive qualities. It enables real‐time assessment which results in the ability to recommend surveillance intervals on the procedure day. It may also reduce polypectomy‐related complications and health‐care costs as diminutive hyperplastic rectosigmoid polyps do not require excision.10 Removal of diminutive polyps is best achieved by cold snare excision. Cold forceps polypectomy should be reserved for polyps <2–3 mm, although cold snare excision is preferred due to the ability to take a margin of normal tissue.12 Furthermore, most complications from polypectomy are caused by the use of diathermy and a high‐quality cold snare technique avoids these sequelae without compromising efficacy. Hot forceps polypectomy (hot biopsy) should be avoided altogether due to the clearly documented small but unacceptable risk of transmural injury with serositis, post‐procedural bleeding and delayed perforation particularly in the context of treatment of a very low‐risk lesion. Moreover, the histological specimen is often extremely degraded and non‐diagnostic and the completeness of resection is unreliable.13
In the current issue of ANZ Journal of Surgery, Sakata et al.16 present a perspective on the optical diagnosis of diminutive polyps. This important mini‐review outlines the advantages and limitations of the technology, the required criteria for its implementation and the current imaging tools such as the Narrow‐band imaging International Colorectal Endoscopic classification criteria which can assist endoscopists in the decision‐making process. As emphasized in this paper, it is important to remember that currently real‐time optical diagnosis is only proven to be accurate in expert hands. However, routine implementation of the ‘resect and discard’ or the ‘diagnose and disregard’ strategy is on the horizon and all colonoscopists must be prepared to embrace its implementation.13
Polyps which are 5–10 mm in size should be resected and retrieved for histopathology. Pedunculated and semi‐pedunculated polyps (Paris 0‐lp and 0‐lsp) of these sizes are best removed by a hot snare using a blend current on the electro‐surgical unit, whereas sessile polyps (Paris 0‐ls and 0‐lla) can be effectively and safely removed by cold snare polypectomy.14 Meticulous snare placement including a margin of 1–2 mm of normal mucosa is required, as incomplete resection is not uncommon and described in up to 10% of polyps.18
Large thick stalked (>10 mm) pedunculated adenomas are uncommon. Post‐polypectomy bleeding risk is increased due to the presence of large feeding vessels in the stalk and prophylactic measures such as endoloop placement, adrenaline injection or endoscopic clips have been applied to the stalk before resection with variable results.19 Meta‐analysis of these various trials shows a benefit for prophylactic treatment of the stalk to prevent post‐polypectomy bleeding.21
Endoscopic removal of large LSL requires special considerations; however, it is increasingly recognized as the standard of care as modelling shows it is more cost‐effective and safer than surgery.
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