Practical Gastrointestinal Endoscopy

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CHAPTER 7
duodenal polypectomy or for the resection of dysplastic or early
malignant areas in the esophagus or stomach. Esophageal or
gastric resections tend to be extensive and there is a higher risk
of both bleeding and perforation when snaring duodenal polyps,
compared with those in the colon. Snare-loop biopsy for diagnostic
purposes (Ménétrier’s disease, etc.) is useful in the stomach
but some caution is needed because it is easy to take a much
bigger bite than intended when assessing using a wide-angle
of view in a large viscus. Gastric polyps are more often trivial
and non-neoplastic than adenomatous, and tend to be small and
easily managed; the innumerable shiny ‘fundic gland polyps’
in the gastric body and fundus of many FAP patients (and a few
others) can be entirely ignored. Peutz–Jeghers polyps may be
larger but are usually thin-stalked and easy to snare. It is wise to
suppress gastric acid for 1 week after any upper GI polypectomy
to reduce the likelihood of delayed hemorrhage. Gastric and
duodenal resection specimens are easily lost after snaring, so
use of antispasmodics and a quick eye and hand are desirable. A
nylon retrieval net is the ideal means for safe retrieval of larger
or multiple specimens because of the obvious need to safeguard
the airways during withdrawal.
Perforation is more likely in theduodenum and small intestine because
the wall is thin, so there is a corresponding need for greater caution
in snaring and electrosurgery. The endoscopist’s role in FAP
patient upper GI tract surveillance is fortunately mainly limited
to inspection at 1–3-yearly intervals, with representative biopsies
for dysplasia grade. Papillary resection for high-grade dysplasia
is a rare possibility. The large sessile polyps that occur in the
peripapillary area of less than 10% of FAP patients are distinctly
hazardous to remove except by endoscopic mucosal resection
(EMR), whereas the frequent tiny polyps or pale dysplastic areas
can be ignored. Polyps with severe dysplasia histologically or
size approaching1·cm require removal by mucosectomy or snaring.
Open surgery, usually Whipple’s operation (with subtotal
pancreatectomy), is the ‘last-ditch’ option the endoscopist is
seeking to avoid.
The technique of suction cap EMR has particular application for
duodenal polypectomy as well as, more frequently, for ‘piecemeal’
removal of areas of high-grade dysplasia or early cancer
in esophageal or gastric mucosa. It is rarely needed in the colon,
since simple injection polypectomy is easier. Suction cap EMR
requires a little endoscopic dexterity but is remarkably safe and
effective:
1–Preload the transparent EMR suction cap onto the tip of the
gastroscope (Fig. 7.43a).
2–If several resections are expected, also preload an overtube
over the endoscope shaft.