Excerpt from Duodenum, Ulcers


Synonyms, Key Words, and Related Terms: DU, peptic ulcer, gastric ulcer, Helicobacter pylori, H pylori, Zollinger-Ellison syndrome

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Background: Duodenal ulcers (DUs) affect nearly 10% of the adult population at some time (Levine, 2000). DUs account for two thirds of all peptic ulcers, which are defined as mucosal breaks >3 mm, and gastric ulcers account for the rest. Unlike gastric ulcers, which may be malignant in about 5% of cases (Levine, 2000), DUs are almost invariably benign; therefore, treatment with antisecretory drugs can be commenced after radiologic diagnosis, without endoscopy being performed beforehand.

Pathophysiology: The most common cause of DUs is infection with Helicobacter pylori (Pattison et al, 1997; Peek and Blaser, 1997; Suerbaum and Michetti, 2002). About 90% of DUs and 70-75% of gastric ulcers are associated with H pylori infection. The second most common cause of DUs is the use of nonsteroidal anti-inflammatory drugs (NSAIDs), which account for most H pylori–negative ulcers (Lanas et al, 1997).

Severe physiologic stress (eg, burns, surgery, head injury) may induce peptic ulceration. Other causes are relatively rare and include gastrinoma (ie, Zollinger-Ellison syndrome) and radiation- or chemotherapy-induced ulcers. Several diseases are associated with an increased risk of peptic ulceration; these include cirrhosis, chronic pulmonary disease, renal failure, and renal transplantation.

Frequency:

  • In the US: About 4.5 million people are affected annually, and approximately 10% of the population has evidence of a DU at some time (Levine, 2000). The prevalence of DU is estimated to be 6-15% in the general population; this is linked to the presence of H pylori. In those infected with H pylori, the lifetime prevalence is approximately 20% (Levine, 2000). Overall, the incidence of DU has been decreasing over the past 3-4 decades.
  • Internationally: The frequency rates of DUs in other countries are variable and are determined primarily by association with their major causes: H pylori infection and NSAID use.

Mortality/Morbidity: DU causes significant morbidity related to pain. Hospitalization is required mainly for complications such as ulcer hemorrhage, perforation, penetration, and obstruction. The annual rate of any complication in patients of all age groups is approximately 1-2% per ulcer (Levine, 2000).

The mortality rate associated with ulcer hemorrhage has remained about 5% over the past 20 years, despite advances in medical therapy. However, in patients who require surgical intervention for complications, such as perforation and obstruction, the mortality rate is significantly higher in the elderly than in other age groups.

Sex: The prevalence has shifted from a male predominance to similar occurrences in males and females. The lifetime prevalence is approximately 11-14% for men and approximately 8-11% for women (Levine, 2000).

Age: DU rates in younger men are decreasing, but they are increasing in older women. These trends reflect the prevalence of H pylori infection and the use of NSAIDs in older populations.

Anatomy: The duodenum consists of 4 parts. The duodenal bulb, or cap, and the pars superior make up the first part. The second part consists of the descending duodenum, where the duodenal papilla and ampulla of Vater are located. The ampulla of Vater contains the outlet of the conjoined or separate pancreatic and bile ducts. The third part consists of the horizontal duodenum and extends from the second part to the arteriomesenteric bundle, where the superior mesenteric artery crosses anterior to the duodenum. The fourth, or ascending, part extends from this point to the duodenojejunal flexure.

Clinical Details:

The patient's history may include the following features:

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