Upper Endoscopy Upper endoscopy, also referred to as esophagogastroduodenoscopy (EGD), is performed by passing a flexible endoscope through the mouth into the esophagus (Figs. 272-1, 272-2, 272-3, 272-4, and 272-5), stomach (Figs. 272-6, 272-7, 272-8, 272-9, and 272-10), bulb (Figs. 272-11, 272-12), and second duodenum. The procedure is the best method of examining the upper gastrointestinal mucosa. While the upper gastrointestinal radiographic series has similar accuracy for diagnosis of duodenal ulcer, EGD is superior for detection of gastric ulcers, detects flat mucosal lesions such as those of Barrett's esophagus, and permits directed biopsy and endoscopic therapy, if needed. Topical pharyngeal anesthesia is used, and 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 without sedation. Patient tolerance of unsedated EGD is improved by the use of an ultrathin, 5-mm diameter endoscope. | | Figure 272-1 Normal esophagus where fine vasculature can be seen. |
| | Figure 272-2 Linear red streaks with a central white streak extend up the esophagus in a peptic regurgitant esophagitus. |
| | Figure 272-3 Ulcerated squamous cell carcinoma, with a depressed center, involving one wall of the esophagus. |
| | Figure 272-4 Moniliasis of the esophagus—a white exudate is seen with underlying erythematous mucosa. |
| | Figure 272-5 Barrett's metaplasia of the esophagus with an adenocarcinoma. The squamocolumnar junction is noted in the proximal esophagus. A mucosal irregularity in the center of the photograph was an adenocarcinoma. |
| | Figure 272-7 Large, benign, lesser curve gastric ulcer—the folds end at the ulcer margin. |
| | Figure 272-8 The histologic type of this gastric polyp must be determined by excision and pathologic examination. |
| | Figure 272-9 An arteriovenus malformation of the gastric mucosa. |
| | Figure 272-10 A normal pylorus. Note the absence of gastric rugal folds in the antrum proximal to the pylorus. |
| | Figure 272-12 A typical duodenal ulcer with a clean base is seen on the anterior surface of the duodenal bulb. |
Colonoscopy Colonoscopy is performed by passing a flexible colonoscope through the anal canal into the rectum and colon. The cecum is reached in >95% of cases, and the terminal ileum can often be examined. Colonoscopy is the "gold standard" for diagnosis of colonic mucosal disease (Figs. 272-13, 272-14, 272-15, 272-16, 272-17, 272-18, 272-19, 272-20, and 272-21). Barium enema is more accurate for evaluation of diverticula and for accurate measurement of colonic strictures, but colonoscopy has greater sensitivity for colitis, polyps, and cancers. Conscious sedation is usually given before colonoscopy in the United States, although a willing patient and a skilled examiner can complete the procedure without sedation in many cases. | | Figure 272-13 Typical folds and vascular pattern can be seen in a normal colon. |
| | Figure 272-14 This colonic adenomatous polyp is erythematous; a stalk is seen covered with normal mucosa. |
| | Figure 272-15 Multiple, small, colonic adenomatous polyps in a case of familial polyposis coli. This colon was removed to prevent the development of cancer. |
| | Figure 272-16 Colon adenocarcinoma—the cancer is multilobed and growing into the lumen. |
| | Figure 272-17 Crohn's colitis with linear, serpiginous, white-based ulcers surrounded by colonic mucosa which is relatively normal. |
| | Figure 272-18 Severe ulcerative colitis with diffuse ulceration, bleeding, and exudation. |
| | Figure 272-19 Kaposi's sarcoma involving the colon in a patient with AIDS. The erythematous lesions involve most of the colonic mucosa in the photograph. |
| | Figure 272-20 In this case of colonic varices, multiple, serpiginous, subephithelial structures impinge on the colonic lumen. |
| | Figure 272-21 The mucosa appears normal in this pouch reconstructed from ileum to provide a reservoir after total proctocolectomy and ileoanal anastomosis. |
Flexible Sigmoidoscopy Flexible sigmoidoscopy is similar to colonoscopy but visualizes only the rectum and a variable portion of the left colon, typically to 60 cm from the anal verge. This procedure causes abdominal cramping, but it is brief and is almost always performed without sedation. Flexible sigmoidoscopy is used for colorectal cancer screening and for evaluation of diarrhea and hematochezia. Small-Bowel Enteroscopy Two techniques are currently used to evaluate the small intestine, most often in patients with unexplained small-bowel bleeding. Push enteroscopy is performed with a long endoscope similar in design to an upper endoscope. The enteroscope is pushed down the small bowel with the help of a stiffening overtube that extends from the mouth to the duodenum. The mid-jejunum is usually reached, and the endoscope's instrument channel allows for biopsies or endoscopic therapy. Capsule endoscopy involves the patient swallowing a disposable capsule containing a charge-coupled device chip. Color still images (Fig. 272-22) are transmitted wirelessly to an external receiver at fixed intervals until the capsule's battery is exhausted or it is passed into the toilet. Much of the jejunal and ileal mucosa is usually visualized. | | Figure 272-22 Capsule endoscopy image of a jejunal vascular ectasia. (Courtesy of Dr. Blair Lewis.) |
Endoscopic Retrograde Cholangiopancreatography (ERCP) During ERCP, a side-viewing endoscope is passed through the mouth to the duodenum, the ampulla of Vater is identified and cannulated with a thin plastic catheter, and radiographic contrast material is injected into the bile duct and pancreatic duct under fluoroscopic guidance (Fig. 272-23, 272-24, and 272-25). When indicated, the sphincter of Oddi can be opened using the technique of endoscopic sphincterotomy (Fig. 272-26). Stones can be retrieved from the ducts, and strictures of the ducts can be biopsied, dilated, and stented. ERCP is often performed for therapy but remains important in diagnosis, especially for bile duct stones. | | Figure 272-23 Normal papilla of Vater—bile is seen adjacent to the papilla. |
| | Figure 272-24 Periampullary carcinoma—the mass at the papilla of Vater has been catheterized during ERCP. |
| | Figure 272-25 Endoscopic retrograde cholangiopancreatography (ERCP) for bile duct stones with cholangitis. A. Faceted bile duct stones are demonstrated in the common bile duct. B. After endoscopic sphincterotomy, the stones are extracted with a Dormia basket. A small abscess communicates with the left intrahepatic duct. |
| | Figure 272-26 Endoscopic sphincterotomy. A. A normal-appearing ampulla of Vater. B. Sphincterotomy is performed with electrocautery. C. Bile duct stones are extracted with a balloon catheter. D. Final appearance of the sphincterotomy. |
Endoscopic Ultrasound (EUS) EUS utilizes high-frequency ultrasound transducers incorporated into the tip of a flexible endoscope. Ultrasound images are obtained of the gut wall and adjacent organs, vessels, and lymph nodes. By sacrificing depth of ultrasound penetration and bringing the ultrasound transducer close to the area of interest via endoscopy, very high resolution images are obtained. EUS provides the most accurate preoperative local staging of esophageal, pancreatic, and rectal malignancies, although it does not detect most distant metastases. Examples of EUS tumor staging are shown in Fig. 272-27. EUS is also highly sensitive for diagnosis of bile duct stones, gallbladder disease, submucosal gastrointestinal lesions, and chronic pancreatitis. Fine-needle aspiration of masses and lymph nodes in the posterior mediastinum, abdomen, and pelvis can be performed under EUS guidance (Fig. 272-28). | | Figure 272-27 Local staging of gastrointestinal cancers with endoscopic ultrasound. In each example the white arrowhead marks the primary tumor and the black arrow indicates the muscularis propria (mp) of the intestinal wall. "AO" indicates aorta. A. T1 gastric cancer. The tumor does not invade the mp. B. T2 esophageal cancer. The tumor invades the mp. C. T3 esophageal cancer. The tumor extends through the mp into the surrounding tissue, and focally abuts the aorta. |
| | Figure 272-28 Endoscopic ultrasound (EUS)–guided needle aspiration. A. Ultrasound image of a 22-gauge needle passed through the duodenal wall and positioned in a hypoechoic pancreatic head mass. B. Micrograph of aspirated malignant cells. (Image B courtesy of Dr. Mary Chacho.) |
|
