Gastric outlet obstruction (GOO) is a clinical syndrome characterized by epigastric abdominal pain and postprandial vomiting due to mechanical obstruction.
The incidence of gastric outlet obstruction is not known precisely. It is likely to have declined in recent years because of the decline in peptic ulcer disease, which has historically been an important cause of GOO. In 1990, as many as 2000 operations for GOO were performed annually in the United States . Updated estimates are not available, but the need for surgery is thought to have declined because of advancements in endoscopic methods to treat GOO (such as dilation and stenting).
The term gastric outlet obstruction is a misnomer since many cases are not due to isolated gastric pathology but rather involve duodenal or extraluminal disease. The predominant causes have changed substantively with the identification of Helicobacter pylori and the use of proton pump inhibitors. Until the late 1970s, benign disease was responsible for the majority of cases of GOO in adults, while malignancy accounted for only 10 to 39 percent of cases [2-4]. By contrast, in recent decades, 50 to 80 percent cases have been attributable to malignancy [2,4-6].
Malignancy — Pancreatic adenocarcinoma with extension to the duodenum or stomach is a common cause of malignant GOO . Fifteen to 25 percent of patients with pancreatic cancer present with GOO . Such patients also commonly have biliary obstruction [8-11]. (See "Clinical manifestations, diagnosis, and staging of exocrine pancreatic cancer".)
Distal gastric cancer remains a relatively common cause of malignant GOO, accounting for up to 35 percent of GOO . However, the absolute number of cases has probably declined because of the decreased incidence of gastric cancer in developed nations and the increase in the proportion of gastric cancers arising from a proximal location. (See "Clinical features, diagnosis, and staging of gastric cancer" and "Epidemiology of gastric cancer".)