Practical Gastrointestinal Endoscopy

THERAPEUTIC COLONOSCOPY 189
Fig. 7.40 (a) Inject broad-stalked
polyps with epinephrine before
snaring to avoid bleeding.
(b) For long-stalked polyps with
a risk of bleeding inject sclerosant
and epinephrine.
Stalk preinjection with epinephrine before snaring makes immediate
bleeding unlikely (Fig. 7.40a). Epinephrine (1–10·mL
1:10 ·000 dilution in 0.9–1.8% (1·N or 2·N) saline) is injected at
one or more sites into the base of the polyp and causes visible
blanching from vessel contraction within a minute or so. The
endoscopist sees blanching and swelling of the stalk and finally
mauve coloration of the ischemic head. Transection through the
upper part of the stalk or above the injected area can then be
made in the certain knowledge that there will be no bleeding.
Nylon EndoLoops® or metal clipping devices are particularly relevant
to large-stalked polyps or, in patients on anticoagulants
or aspirin, as a way of strangulating the remaining stalk. The
most certain method for larger stalks is the nylon self-retaining
EndoLoop® (Fig. 7.41). The loop is usually placed on the stalk
remnant after polypectomy, because the floppy loop is difficult to
maneuver over a polyp head of 2·cm or more. For smaller stalks,
one or more metal clips can be placed easily before or after snaring.
Clips are particularly useful in controlling local bleeding
after sessile polypectomy, when there is no stalk on which to
close a loop.
Recovery of polypectomy specimens
Extraction of large polyps (3·cm or more) through the anal
sphincters can be difficult. The polyp will often fragment if
excessive traction is needed on the snare or retrieval grasper,
although a multi-wire Dormia basket or polyp-retrieval nylon
net should avoid this. Once at the anus ask the patient to bear
down ‘as if to pass wind’ in order to relax the sphincters; at the
same time gentle traction is applied to produce the polyp (cover
the perineal area to avoid explosive surprises!). If withdrawal
fails in the left lateral position, ask the patient to squat on the floor
or sit on a commode seat, which is more physiological and(with
traction maintained on the retrieval device) rapid expulsion of
the polyp invariably results—compensating for any embarrassment
about the maneuver. Alternatively, a split overtube can be
inserted into the rectum over the colonoscope, the polyp pulled
Fig. 7.41 (a) A nylon self-retaining
loop can be placed over a
large stalk …(b)… and its self-retaining
cuff tightened; (c)… and
the loop unhooked leaving the
stalk strangulated.