Gastrointestinal endoscopy has been attempted for over 200 years, but the introduction of semirigid gastroscopes in the middle of the twentieth century marked the dawn of the modern endoscopic era. Since then rapid advances in endoscopic technology have led to dramatic changes in the diagnosis and treatment of many digestive diseases. Innovative endoscopic devices and new endoscopic treatment modalities continue to expand the use of endoscopy in patient care.
Flexible endoscopes provide an electronic video image generated by a charge-coupled device in the tip of the endoscope. Operator controls permit deflection of the endoscope tip; fiberoptic bundles or light-emitting diodes provide light at the tip of the endoscope; and working channels allow washing, suctioning, and the passage of instruments (Fig. 315-1). Progressive changes in the diameter and stiffness of endoscopes have improved the ease and patient tolerance of endoscopy.
Gastrointestinal endoscope. Shown here is a conventional colonoscope with control knobs for tip deflection, push buttons for suction and air insufflation (single arrows), and a working channel for passage of accessories (double arrows).
Upper endoscopy, also referred to as esophagogastroduodenoscopy (EGD), is performed by passing a flexible endoscope through the mouth into the esophagus, stomach, and duodenum. The procedure is the best method for examining the upper gastrointestinal mucosa (Fig. 315-2). While the upper gastrointestinal radiographic series has similar accuracy for diagnosis of duodenal ulcer (Fig. 315-3), EGD is superior for detection of gastric ulcers (Fig. 315-4) and flat mucosal lesions, such as Barrett’s esophagus (Fig. 315-5), and it permits directed biopsy and endoscopic therapy. Intravenous conscious sedation is given to most patients in the United States to ease the anxiety and discomfort of the procedure, although in many countries EGD is routinely performed with topical pharyngeal anesthesia only. Patient tolerance of unsedated EGD is improved by the use of an ultrathin, 5-mm diameter endoscope that can be passed transorally or transnasally.
Normal upper endoscopic examination. A. Esophagus. B. Gastroesophageal junction. C. Gastric fundus. D. Gastric body. E. Gastric antrum. F. Pylorus. G. Duodenal bulb. H. Second portion of the duodenum.