Page 21 - Gastrointestinal Bleeding (Xuất huyết tiêu hóa)

CHAPTER 20 Gastrointestinal Bleeding 295

Dieulafoy Lesion been reported in patients who vomit while taking a bowel purge
before colonoscopy. 186 Endoscopy usually reveals a single tear 20
A Dieulafoy lesion is a large (1- to 3-mm) submucosal artery that begins at the gastroesophageal junction and extends several
that protrudes through the mucosa, is not associated with a pep- millimeters distally into a hiatal hernia sac. Occasionally, more
tic ulcer, and can cause massive bleeding. It is usually located in than one tear is seen. A retroflexed view in the stomach may
the gastric fundus, within 6 cm of the gastroesophageal junction, provide better visualization than a forward view. The bleeding
although lesions in the duodenum, small intestine, and colon stigmata of Mallory-Weiss tears can include a clean base, adher-
have been reported. The cause is unknown, and congenital and ent clot, NBVV, oozing, or, rarely, active spurting. Usually, the
acquired (related to mucosal atrophy or an arteriolar aneurysm) bleeding is self-limited and mild, but occasionally it can be severe,
causes are thought to occur (see Chapter 38). especially in patients with esophageal varices or coagulopathies.
Dieulafoy lesion can be difficult to identify at endoscopy Mucosal (superficial) Mallory-Weiss tears can start healing within
because of the intermittent nature of the bleeding; the overly- hours and can heal completely within 48 hours.
ing mucosa may appear normal if the lesion is not bleeding. An Although approximately 50% of patients hospitalized with
NBVV or adherent clot without an ulcer may be seen on endos- UGI bleeding from a Mallory-Weiss tear receive blood transfu-
copy. If a massive UGIB seems to be emanating from the stom- sions, the tear manifests as mild, self-limited hematemesis in most
ach, careful inspection of the proximal stomach should be carried patients, who do not seek medical care. 187 The rebleeding rate
out to look for a protuberance that might be a Dieulafoy lesion. among patients hospitalized for a Mallory-Weiss tear is approxi-
DEP has been used to help identify a Dieulafoy lesion not visual- mately 10%; risk factors for rebleeding include shock at presen-
ized on endoscopy. 179 Owing to the difficulty of identifying the tation and active bleeding at endoscopy. 188 Owing to the risk of
bleeding site and because rebleeding is not uncommon, we rec- continued and recurrent bleeding, patients with active bleeding
ommend that if a Dieulafoy lesion is found and treated, the site from a Mallory-Weiss tear should undergo endoscopic therapy,
should be marked with submucosal injection of ink to tattoo the which can be performed successfully with epinephrine injection,
area in case of rebleeding and the need for retreatment. MPEC, hemoclip placement, or band ligation. Randomized trials
Endoscopic hemostasis of a Dieulafoy lesion can be performed that compared MPEC and medical therapy with an H2RA have
with injection therapy, a thermal probe, hemoclipping, OTSC found that endoscopic therapy reduces the rates of rebleeding,
hemoclipping, or rubber band ligation. 111,179-185 Large case series blood transfusions, and emergency surgery. 189
have reported an initial hemostasis rate of approximately 90%, Our current endoscopic technique for treating actively bleed-
with the need for surgery in 4% to 16% of cases. 182 Rebleeding ing Mallory-Weiss tears in patients without portal hypertension
rates may be lower with combination therapy or OTSC hemo- or esophageal varices is to apply endoscopic hemoclips to stop
clipping because underlying arterial blood flow is eradicated the bleeding and close the tear. If hemoclips are unavailable, epi-
more effectively than by injection or monotherapy. 111 Although nephrine injection to slow bleeding and focal hemostasis of the
all the endoscopic hemostasis techniques seem to be effective, bleeding site with MPEC at a low-power setting (12 to 14 W) and
perforation and delayed rebleeding have been reported after band with light pressure applied for 1 to 2 seconds are recommended.
ligation (see Chapter 42). The management of patients with esophageal varices caused by
portal hypertension who also have a Mallory-Weiss tear should
Mallory-Weiss Tears be targeted toward the esophageal varices, with esophageal band
ligation or variceal sclerotherapy (see later and Chapter 92).
Mallory-Weiss tears are mucosal or submucosal lacerations that Patients with a Mallory-Weiss tear are also treated with anti-
occur at the gastroesophageal junction and usually extend distally emetics if they have nausea or vomiting, and a PPI to accelerate
into a hiatal hernia (Fig. 20.14). Patients generally present with mucosal healing. Long-term treatment with a PPI is not required.
hematemesis or coffee-ground emesis and a history of nonbloody
vomiting followed by hematemesis, although some patients do Cameron Lesions
not recall vomiting. The tear is thought to result from increased
intra-abdominal pressure, in combination with a shearing effect Cameron lesions are linear erosions or ulcerations in the proxi-
caused by negative intrathoracic pressure above the diaphragm, mal stomach at the end of a large hiatal hernia, near the diaphrag-
which is often related to vomiting. Mallory-Weiss tears have matic pinch (Fig. 20.15). 190 Cameron lesions are thought to be
caused by mechanical trauma and local ischemia as the hernia
moves against the diaphragm and only secondarily by acid and
pepsin. They can be a source of acute UGI bleeding but more
commonly may present as chronic GI bleeding and iron defi-
ciency anemia. Cameron lesions are a common cause of obscure
GI bleeding (see later) and, not uncommonly, are missed by an
unsuspecting endoscopist. Endoscopic management has been
reported. 191 Long-term medical management is usually with iron
supplements and an oral PPI. 192,193 Surgical repair of the hiatal
hernia may be needed for patients with severe acute or chronic GI
bleeding and failure of medical management (see Chapter 27). 192

UGI Malignancy
Malignancy accounts for 1% of severe UGIBs. The tumors are
usually large, ulcerated masses in the esophagus, stomach, or duo-
denum. Endoscopic hemostasis with MPEC, laser, injection ther-
apy, or hemoclips can temporarily control acute bleeding in most
patients and allow time to determine the appropriate long-term
Fig. 20.14 Endoscopic appearance of a Mallory-Weiss tear with mild management. 194,195 Patients with an ulcerated subepithelial mass
oozing. Note that the tear starts at the gastroesophageal junction (long (usually a GIST or leiomyoma) should undergo surgical resec-
arrow) and extends distally into the hiatal hernia (short arrow). tion of the mass to prevent rebleeding and, in the case of a GIST,