more than 70% of patients, and a second treatment increases the rate of control from 90% to 95%.

Continued or recurrent hemorrhage after endoscopic treatment often requires emergency portal

decompression either with transjugular intrahepatic portosystemic shunting (TIPS) or rarely

surgery.144–146 Following an initial episode of variceal hemorrhage several options are available for the

prevention of further hemorrhage. These options, as well as the operative management of bleeding

esophageal varices are discussed in detail in Chapter 59.

Mallory–Weiss Tears

The Mallory–Weiss syndrome is acute UGI hemorrhage that occurs after retching or vomiting. Mallory

and Weiss described the laceration of the gastric cardia and postulated that violent emesis against an

unrelaxed cardia was the mechanism of injury. They were able to produce similar mucosal tears in

cadavers by forcing gastric contents against an occluded gastroesophageal junction.147 The typical

patient is an alcoholic who begins to retch and vomit after an alcohol binge although this syndrome may

also be found in nonalcoholics with bouts of emesis. Initially the vomitus consists of gastric contents

without blood and subsequently the patient develops hematemesis and/or melena. Overall, these lesions

account for about 5% to 10% of patients with UGI bleeding.120,136,148

The initial management of these patients is similar to that of patients bleeding from other sources of

UGI hemorrhage and includes volume resuscitation, gastric lavage, and decompression. Most patients

with Mallory–Weiss tears stop bleeding spontaneously, either before treatment or after these early

measures. Once bleeding has stopped, rebleeding is rare.

In patients who continue to bleed despite these maneuvers, nonoperative and operative therapeutic

options are available. Nonoperative management, consisting of endoscopic electrocoagulation, banding

or injection therapy, has been successfully applied to these lesions.149 In cases not amenable to

endoscopic therapy, operative management consists of oversewing the laceration through an anterior

longitudinal gastrotomy in the middle third of the stomach.

LOWER GI HEMORRHAGE

Although the passage of maroon or bright red blood per rectum may occur in the presence of a massive

UGI hemorrhage, this finding most commonly indicates a source distal to the ligament of Treitz. The

absence of blood in bilious nasogastric lavage further supports a distal location of hemorrhage.

Although numerous potential causes of LGI hemorrhage are possible (Table 65-2), colonic diverticulosis

and colitis are by far the most common. Small bowel sources and other colonic pathology such as colon

cancer are relatively unusual causes of acute GI hemorrhage.

Diagnostic Approach

The most important question to answer when presented with a patient with LGI hemorrhage is not,

“What is bleeding?” but rather, “Where is the bleeding?” The common causes of colonic hemorrhage are

mucosal in nature, not palpable, and not visible from the serosal surface of the bowel. Therefore, it is

imperative that the surgeon makes every effort to localize the source of bleeding preoperatively since it

is usually impossible to locate intraoperatively. If the surgeon waits to attempt localization until it is

clear that surgical treatment will be required it may be too late. Colonoscopy, tagged RBC scanning

and/or angiography should be obtained as early as possible after presentation.

After determination that the bleeding is likely from an LGI source, it is important to first exclude

anorectal causes of hemorrhage, such as hemorrhoidal bleeding. At this point, colonoscopy is usually

performed as it can rule out anorectal causes of bleeding, but also help determine non-anorectal causes

of hemorrhage. In the authors’ experience, despite studies showing high value, colonoscopy in an

actively bleeding patient with an unprepped colon is seldom therapeutic. However, it can be of

significant diagnostic benefit. It is usually fairly easy to determine when bleeding is from a neoplasm,

and noting the location helps guide the surgeon in decision making. Conversely in AVMs and

diverticular bleeding, locating the actual source of bleeding is often unsuccessful due to the presence of

blood and stool. However, noting the extent of blood in the colon can be helpful to guide future surgical

decision making. For example, if blood is only noted in the sigmoid colon and rectum, this suggests

bleeding is from a distal source and a sigmoid colectomy may suffice if bleeding persists. Alternatively

if blood is noted throughout the entire colon, the location of the bleed is unclear and a total colectomy

may be necessary. The terminal ileum should be intubated as well. While a small amount of blood can

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reflux into the terminal ileum, if an extensive amount of blood is noted then a small bowel source

should be considered and the surgeon should be hesitant about performing a total colectomy if bleeding

persists.

Alternatively, a tagged RBC scan can be obtained as soon as practical, or in occasional cases of

massive hemorrhage, conventional angiography or MDCT. If the tagged RBC scan localizes a bleeding

site, the patient is then sent for angiography to attempt to embolize the bleeding vessel. If the tagged

RBC scan does not demonstrate bleeding, then it is probable that bleeding has stopped. One may then

proceed to colonoscopy after adequate mechanical bowel preparation.

If the bleeding is rapid enough to warrant emergency surgery, bleeding can usually be demonstrated

by tagged RBC scan, MDCT, or angiography. It should be the very rare patient who will need to

proceed to surgery for LGI hemorrhage with failed preoperative localization. In these cases a careful

search for small bowel bleeding sources, possibly including intraoperative small bowel endoscopy,

should be performed.

Colonic Diverticulosis

9 In Western society, the prevalence of colonic diverticula increases with age such that about 60% of

people in their seventh decade of life are affected and the incidence increases roughly 1% per year.

Only about 20% of patients with diverticulosis have symptoms attributable to these lesions and less than

5% experience hemorrhage.150 Hemorrhage from diverticular disease is most often massive, associated

with hematochezia, and accompanied by varying degrees of hemorrhagic shock. Classically, patients

present with a sudden occurrence of mild lower abdominal discomfort, rectal urgency, and the

subsequent passage of a large bloody stool. Because the colon can contain large volumes of blood,

neither the volume nor the frequency of bloody stools is a reliable guide to the rate of hemorrhage.

Despite the massive nature of hemorrhage, most patients with diverticular disease stop bleeding

spontaneously. Most series report bleeding ceases spontaneously in 80% of cases, although up to 25% to

50% can rebleed. Of those who rebled, less than one-fourth required surgery.151

Bleeding associated with diverticular disease comes from a perforated vasa recta located at the neck

or apex of a diverticulum. The vasa recta penetrates the colonic wall from the serosa to the submucosa

through obliquely oriented connective tissue septa. Protrusion of colonic mucosa through this

connective tissue plane causes apposition of the diverticulum and the vasa recta (Fig. 65-4). Ulceration

of the mucosa within the neck of the diverticulum and disruption of the arterial wall produces

hemorrhage into the lumen of the bowel. Although diverticular disease is more prevalent in the left

colon, right-sided lesions account for half or more episodes of bleeding.151,152 Risk factors for rebleeding

are hypertension, NSAID use, coagulopathy, renal failure, ischemic heart disease, and cluster type

diverticula.153,154

Figure 65-4. Colonoscopic view of a colonic diverticulum. A vasum rectum is seen entering the diverticulum and forming one of

the walls.

The massive nature of the bleeding caused by colonic diverticula limits the diagnostic usefulness of

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colonoscopy. Rarely is a bleeding vessel seen within a diverticulum and the presence of blood or clot

within a diverticulum is of no diagnostic benefit. Selective mesenteric arteriography may demonstrate

the luminal extravasation of contrast; however, in one study of patients bleeding from diverticulosis,

angiographic localization was effective in less than 20% of patients.155 Failure to visualize a bleeding

point is usually due to cessation of active bleeding at the time of angiography.

Given the relatively low risk of recurrent hemorrhage, patients who stop bleeding should be treated

expectantly. About 10% of patients bleeding from colonic diverticula continue to bleed and ultimately

require operative intervention. Embolization of bleeding vessels in the colon has been reported to be

safe and effective in the majority of patients; however there is a definite risk of ischemic

complications.156,157 The rapid nature of the hemorrhage and the difficulty in defining the site of

bleeding through the endoscope can limit endoscopic attempts at control of diverticular hemorrhage,

especially in patients with large volume rapid bleeding.

If the site of bleeding can be localized, patients who continue to bleed from diverticular disease

should undergo resection of the colon segment that contains the site of bleeding. Even after successful

localization of a bleeding source, the least operation that can usually be contemplated is a

hemicolectomy or wide segmental colectomy. Segmental colon resection has been associated with

rebleeding rates of only 0% to 15% and mortality rates of 0% to 13%. Tagged RBC scanning, while

sensitive, cannot always pinpoint a bleeding site with great accuracy. Although angiography usually

gives more precise localization, correlation between the vascular pattern and the anatomic location is

sufficiently imprecise to warrant at least a segmental resection. Finally, measurement with colonoscopy

is notoriously misleading with even experienced endoscopists making mistakes about the precise site of

a lesion. If the location is unable to be localized and the blood appears confined to the colon, a total

abdominal colectomy should be performed as most studies show rebleeding rates of 0%, and “blind”

segmental colectomy has been shown to have a rebleeding rate of up to 75%.65 However, the surgeon

and patient should be aware of a failure rate even after total abdominal colectomy as the small bowel

could potentially be the source. There are few worse sights for the surgeon than blood coming from an

ileostomy after a blind total abdominal colectomy for bleeding.

Although a total colectomy, often with end ileostomy, for nonlocalized ongoing colonic hemorrhage

may occasionally be necessary, it should be performed only after exhaustive attempts to localize the site

of bleeding. Total colectomy is associated with greater perioperative morbidity rates than segmental

resection and postoperative volume losses from ileostomies or diarrhea may present a significant

problem to elderly patients.

Colonic Angiodysplasia

Sometimes called vascular ectasias or arteriovenous malformations, these lesions are believed to arise

from the age-related degeneration of previously normal intestinal submucosal veins and overlying

mucosal capillaries. Angiodysplasia is located most frequently in the cecum and ascending colon,

although it may be found more distally in 20% to 30% of cases. Multiple lesions may be present in as

many as 40% to 75% of all cases.158 Microscopically, angiodysplasia consists of dilated, thin-walled

vessels that appear to be ectatic veins and venules localized within the submucosa. A dilated submucosal

vein is often found and occasionally an enlarged artery. Angiodysplasia is generally thought to be an

acquired lesion associated with aging, but the exact etiology is unknown.

The prevalence of colonic angiodysplasia in the general population appears to be less than 1%.159

These lesions may present with hematochezia, melena, occult blood loss, or iron-deficiency anemia.

Bleeding lesions are most commonly found in the right colon. As compared to diverticular bleeding,

episodes of hemorrhage from vascular ectasias are usually less severe, and are somewhat more likely to

recur. After the initial episode of hemorrhage, the majority of patients will stop bleeding

spontaneously.160

Vascular ectasias may be diagnosed by either colonoscopy or by selective mesenteric angiography.

Colonoscopy has been reported to have a sensitivity of 80% in demonstrating vascular ectasias.161

However, colonoscopic diagnosis of these lesions in actively bleeding patients may be confounded by

the presence of other incidental lesions including traumatic and suction artifacts produced during the

examination. In addition, after significant bleeding and hypovolemia, the shunting of blood flow away

from the intestinal mucosa may obscure these lesions in inadequately resuscitated patients. When

vascular ectasias are located, colonoscopy can be used effectively to treat vascular ectasias either by

coagulation or possibly injection of sclerosants.162,163

Selective mesenteric angiography may also demonstrate these lesions and compliment colonoscopy,

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