Duodenal ulcers are more common than gastric ulcers and tend to occur anteriorly. Ulcers located on the anterior wall of the duodenal bulb are more prone to perforation; those on the posterior wall are more likely to cause hemorrhage.
These complications are explained by the relationship of the duodenal bulb to adjacent organs. The bulb begins at the pylorus, ends at the neck of the gallbladder, and rests posteriorly to the gallbladder and liver. The gastroduodenal artery, common biliary duct, and portal vein lie posterior to the duodenal bulb; the head of the pancreas is located inferiorly. When an ulcer penetrates the posterior duodenal wall, it is likely to erode into the gastroduodenal artery.
The gastroduodenal artery arises from the common hepatic artery and perfuses both the pylorus and the proximal part of the duodenum. Damage to the gastroduodenal artery can cause significant upper gastrointestinal bleeding.
(Choice A) The common hepatic artery arises from the celiac trunk and bifurcates into the proper hepatic and gastroduodenal arteries. It passes superior to the duodenal bulb and is not eroded by duodenal ulcers.
(Choices B and C) The right gastroepiploic and left gastric arteries supply blood to the stomach. They do not lie close to the duodenal bulb.
The gastroduodenal artery lies along the posterior wall of the duodenal bulb and is likely to be eroded by posterior duodenal ulcers. Ulceration into the gastroduodenal artery can be a source of life-threatening hemorrhage.