Gastrointestinal (GI) bleeding is a very common and potentially life-threatening pathology encountered by the Emergency Physician. It accounts for more than 400,000 hospital admissions each year, with mortality rates as high as 15%.1 Expedient recognition, diagnosis, resuscitation, and treatment of the underlying etiology are essential in preventing morbidity and mortality. The initial resuscitation to achieve hemostasis is paramount in the Emergency Department and often overshadows the search for the underlying etiology. The origin of the bleeding directs the algorithm for further management after stabilization.
Since its introduction and approval by the U.S. Food and Drug Administration (FDA) approximately 15 years ago, video capsule endoscopy has been increasingly used. A pill-sized camera is swallowed, and real-time images of the GI tract are visualized. There have been more than two million video capsule endoscopies performed worldwide and thousands of research papers on its various aspects.2 Video capsule endoscopy has shown significant promise and is quickly becoming one of the mainstays of medical management when compared to traditional methods of diagnosis and risk stratification.
This chapter introduces the use of video capsule endoscopy, a relatively novel method for the rapid diagnosis and risk stratification of acute GI bleeds. Video capsule endoscopy can be used in the Emergency Department. An Emergency Physician must be familiar with its potential complications and current limitations.
ANATOMY AND PATHOPHYSIOLOGY
The human GI system is divided into three main components derived from their embryological origins (i.e., the foregut, midgut, and hindgut). The foregut gives rise to the abdominal esophagus, the stomach, the proximal half of the duodenum, the liver, the gallbladder, and the pancreas. The midgut gives rise to the distal half of the duodenum, the jejunum, the ileum, the cecum, the appendix, the ascending colon, and the proximal two-thirds of the transverse colon. The hindgut gives rise to the distal third of the transverse colon, the descending colon, the sigmoid colon, the rectum, and the proximal anal canal. Each of these regions is supplied by a specific branch of the aorta. It should be noted that the branches of these arteries frequently anastomose with each other and provide alternative routes of arterial supply.
The celiac trunk supplies the foregut derivatives. The celiac trunk divides into three branches. The common hepatic artery supplies the liver, gallbladder, stomach, duodenum, and pancreatic head and neck. The left gastric artery supplies the stomach and the esophagus. The splenic artery supplies the spleen, stomach, and the rest of the pancreas.
The superior mesenteric artery supplies the midgut derivatives. The superior mesenteric artery divides into many branches. The inferior pancreaticoduodenal artery supplies the head of the pancreas and the duodenum. The jejunal and ileal branches give rise to 15 to 18 intestinal branches. The middle colic artery supplies the transverse colon. The right colic artery supplies the ascending colon. The ileocolic artery supplies ...