Capsule Endoscopy A SPECIAL ARTICLE

13 INTRODUCTION M illions of people in the United States suffer from diseases leading to abnormalities affecting the small bowel (1); however, accurate imaging of this area has been difficult. Wireless capsule endoscopy is an innovative tool for the investigation of the small bowel and is rapidly gaining acceptance as the gold standard for its evaluation. Unlike the upper gastrointestinal tract or the colon, where upper endoscopy and colonoscopy has become standard of care for the diagnosis and treatment of intra-luminal disorders, routine diagnostic tools for the evaluation of the small bowel have been suboptimal and incomplete. The length of the small bowel (variable with average length of 22 feet or 6.7 meters), its free intra-peritoneal location with multiple overlying loops, and its active contractile pattern make conventional endoscopic and radiologic exams inadequate (2). Contrast examination via small bowel follow through (SBFT) was previously felt to be the mainstay for the complete evaluation of the small intestines. Although large masses and ulcerations are clearly visualized during these examinations, flat lesions or limited mucosal disease may be missed. Studies have found the diagnostic yield of SBFT in patients with iron deficiency anemia and obscure gastrointestinal (GI) blood loss to be quite disappointing, ranging from zero to six percent (3–6). While several studies have suggested the superiority of small bowel enteroclysis over standard small bowel barium exams, overall diagnostic yields remain low, ranging from 10% to 25% (7–10). Over the past decade, endoscopic examination of the small bowel (small bowel enteroscopy) has emerged as an effective alternative for the diagnosis and treatment of small bowel diseases. The three different types of small bowel enteroscopy include Sonde, intra-operative, and push enteroscopy. Sonde enteroscopy, using a three meter long endoscope that possesses limited tip deflection and no working channels, is labor and time intensive, and has largely been abandoned. Intra-operative enteroscopy, as the name implies, is the most invasive modality, and although reported success rates in patients with obscure GI Capsule Endoscopy A SPECIAL ARTICLE