few days to many years; the median interval is about 3 years.179 Most patients have an initial episode of

GI bleeding (i.e., herald bleed) that is followed in hours, days, or weeks by catastrophic hemorrhage.

Patients may also complain of back or abdominal pain and less commonly have fever or signs of sepsis

from infection of the graft.

The diagnosis of an aortoenteric fistula must be considered in any patient with an aortic prosthesis or

an abdominal aortic aneurysm who presents with GI hemorrhage. Endoscopy should be urgently

performed following resuscitation to disclose evidence of an aortoenteric fistula or another cause of

bleeding (e.g., peptic ulcer disease with stigmata of recent hemorrhage). If endoscopy fails to

demonstrate an aortoenteric fistula or another convincing source of bleeding and the patient is not

massively bleeding, computed tomography may be helpful in detecting perigraft infection or other

evidence of an aortoenteric fistula. In patients who are actively bleeding, exploratory laparotomy with

exposure of the proximal graft should be undertaken. Identification of an aortoenteric fistula or erosion

requires resection of the graft with extra-anatomical bypass and repair of the duodenal wall, or aortic

reconstruction using a variety of techniques such as aortic reconstruction with popliteal vein or human

allografts.180 The operative management of aortoduodenal fistulas is considered in greater detail in

Chapter 96.

Meckel Diverticulum

Bleeding from a Meckel diverticulum is a common cause of lower GI hemorrhage in children but is rare

in older adults. Meckel diverticula are present in approximately 2% of the population. The lifetime risk

of a complication from a Meckel diverticulum is about 4%.181 About 25% of patients with symptomatic

Meckel diverticula present with hemorrhage.182 In a series of 17 patients who bled from Meckel

diverticula, 11 experienced frank hemorrhage while 6 had chronic occult blood loss. The incidence of GI

hemorrhage is greatest in the first decade of life and steadily decreases from that point. In one series,

no patient older than 40 years of age, and only one patient older than 31 years, bled from a Meckel

diverticulum,182 although it has been reported in the very elderly.183 The pathogenesis of this bleeding

involves the occurrence of ectopic gastric mucosa with peptic ulceration of adjacent bowel wall.

Although these lesions may be demonstrated by enteroclysis, abdominal scintigraphy following the

intravenous injection of 99technetium-pertechnetate demonstrates the ectopic gastric mucosa within the

diverticulum, suggesting the correct diagnosis. Treatment consists of resecting the diverticulum with

adjacent bowel. Diverticulectomy alone will be associated with persistence of the ulcer and the

possibility of recurrent hemorrhage.

Small Intestinal Diverticulum

Diverticular disease of the small intestine is another uncommon cause of either UGI hemorrhage

(duodenal) or LGI hemorrhage (jejunoileal diverticula).184 The pathogenesis is similar to that of colonic

diverticula with erosion of a vasa recta through the diverticular wall and the acute onset of massive

hemorrhage. Depending on the location of the diverticulum, patients may present with either

hematemesis, melena, or hematochezia. Hemorrhage from this source can be a vexing diagnostic

problem because jejunoileal lesions are beyond the reach of the gastroscope and bleeding from duodenal

diverticula may be difficult to discern. Mesenteric angiography or intraoperative enteroscopy may

localize the site of hemorrhage in actively bleeding patients. Segmental resection of the involved

intestine is the treatment of choice.

Hemorrhage Following Endoscopic Procedures

Significant hemorrhage can occur following endoscopic biopsy, sphincterotomy, and other traumatic

procedures. Fortunately these complications are uncommon. Colonoscopy may rarely cause clinically

significant bleeding (0.1% to 0.2%).185 Biopsy of lesions increase the risk up to 10-fold. Usually this is

minor and self-limited and may occur up to 12 days after the procedure.186 The bleeding site can be

confirmed by tagged red cell scanning, arteriography, or colonoscopy. Arteriography and colonoscopy

can be used therapeutically as described previously. Endoscopically placed bands such as those used for

esophageal varices, have also been reported to be successful in arresting hemorrhage.98 Surgical

treatment is rarely required.

Hemorrhage following endoscopic biliary sphincterotomy occurs in approximately 2% of patients.187

Mild immediate bleeding is common and is usually self-limited. Late hemorrhage usually occurs within

48 hours of the procedure but can occur many days after sphincterotomy.188 More severe hemorrhage

can usually be controlled by epinephrine injection,188 making the need for operative treatment

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uncommon.

References

1. Peura DA, Lanza FL, Gostout CJ, et al. The American College of Gastroenterology Bleeding

Registry: preliminary findings. Am J Gastroenterol 1997;92:924–928.

2. Raju GS, Gerson L, Das A, et al. American Gastroenterological Association (AGA) Institute technical

review on obscure gastrointestinal bleeding. Gastroenterology 2007;133:1697–1717.

3. Laine L, Yang H, Chang SC, et al. Trends for incidence of hospitalization and death due to GI

complications in the United States from 2001 to 2009. Am J Gastroenterol 2012;107:1190–1195.

4. Vreeburg EM, Snel P, de Bruijne JW, et al. Acute upper gastrointestinal bleeding in the Amsterdam

area: incidence, diagnosis, and clinical outcome. Am J Gastroenterol 1997;92:236–243.

5. Lingenfelser T, Ell C. Lower intestinal bleeding. Best Pract Res Clin Gastroenterol 2001;15:135–153.

6. Cappell MS, Friedel D. Initial management of acute upper gastrointestinal bleeding: from initial

evaluation up to gastrointestinal endoscopy. Med Clin North Am 2008;92:491–509, xi.

7. Richter JM, Christensen MR, Kaplan LM, et al. Effectiveness of current technology in the diagnosis

and management of lower gastrointestinal hemorrhage. Gastrointest Endosc 1995;41:93–98.

8. Bramley PN, Masson JW, McKnight G, et al. The role of an open-access bleeding unit in the

management of colonic haemorrhage. A 2-year prospective study. Scand J Gastroenterol

1996;31:764–769.

9. Longstreth GF. Epidemiology and outcome of patients hospitalized with acute lower gastrointestinal

hemorrhage: a population-based study. Am J Gastroenterol 1997;92:419–424.

10. Kok KY, Kum CK, Goh PM. Colonoscopic evaluation of severe hematochezia in an Oriental

population. Endoscopy 1998;30:675–680.

11. Kaplan RC, Heckbert SR, Koepsell TD, et al. Risk factors for hospitalized gastrointestinal bleeding

among older persons. Cardiovascular Health Study Investigators. J Am Geriatr Soc 2001;49:126–

133.

12. Fiaccadori E, Maggiore U, Clima B, et al. Incidence, risk factors, and prognosis of gastrointestinal

hemorrhage complicating acute renal failure. Kidney Int 2001;59:1510–1519.

13. Cheng HC, Chuang SA, Kao YH, et al. Increased risk of rebleeding of peptic ulcer bleeding in

patients with comorbid illness receiving omeprazole infusion. Hepato Gastroenterol 2003;50:2270–

2273.

14. van Leerdam ME, Vreeburg EM, Rauws EA, et al. Acute upper GI bleeding: did anything change?

Time trend analysis of incidence and outcome of acute upper GI bleeding between 1993/1994 and

2000. Am J Gastroenterol 2003;98:1494–1499.

15. Mellemkjaer L, Blot WJ, Sorensen HT, et al. Upper gastrointestinal bleeding among users of

NSAIDs: a population-based cohort study in Denmark. Br J Clin Pharmacol 2002;53:173–181.

16. Verhamme K, Mosis G, Dieleman J, et al. Spironolactone and risk of upper gastrointestinal events:

population based case-control study. BMJ 2006; 333:330.

17. Dalton SO, Johansen C, Mellemkjaer L, et al. Use of selective serotonin reuptake inhibitors and risk

of upper gastrointestinal tract bleeding: a population-based cohort study. Arch Intern Med

2003;163:59–64.

18. Masclee GM, Valkhoff VE, Coloma PM, et al. Risk of upper gastrointestinal bleeding from different

drug combinations. Gastroenterology 2014;147:784–792.e9.

19. Garcia Rodriguez LA, Lin KJ, Hernandez-Diaz S, et al. Risk of upper gastrointestinal bleeding with

low-dose acetylsalicylic acid alone and in combination with clopidogrel and other medications.

Circulation 2011;123:1108–1115.

20. Daniel WA, Egan S. The quantity of blood required to produce a tarry stool. JAMA 1939;113:2232.

21. Schiff L, Stevens RJ, Shapiro N, et al. Observations on the oral administration of citrated blood in

man. II. The effect on the stools. Am J Med Sci 1942;203:409–412.

22. Hilsman JH. The color of blood-containing feces following the instillation of citrated blood at

various levels of the small intestine. Gastroenterology 1999;15:131–134.

23. Barnert J, Messmann H. Management of lower gastrointestinal tract bleeding. Best Pract Res Clin

1700