Contribution of Intraoperative Enteroscopy in the Management of Obscure Gastrointestinal Bleeding Michael L. Kendrick, M.D., Navtej S. Buttar, M.D., Marlys A. Anderson, Lori S. Lutzke, Daniela Peia, Kenneth ~ Wang, M.D., Michael G. Sarg, M.D. Obscure gastrointestinal bleeding remains a significant diagnostic challenge. Our aims were (1) to determine the efficacy of intraoperative enteroscopy (IOE) in identifying lesions responsible for obscure gastrointestinal bleeding and (2) to determine the outcome of patients after treatment of these lesions. We retrospectively reviewed all patients who underwent IOE for obscure gastrointestinal bleeding from 1992 to 1998. Patients were divided into those with overt and those with occult gastrointestinal bleeding. Follow-up was complete in 67 patients (96%), with a median of 32 months (range 1 to 91 months). Sev- enty patients (52 overt and 18 occult) underwent IOE after extensive preoperative evaluation. Median du- ration of bleeding was 12 months, requiring a median of 14 blood transfusions. Risk factors for bleeding were identified in 46 patients (61%). A lesion was identified and treated in 52 patients (74%)--39 in the overt group and 13 in the occult group. Lesions identified were vascular (54%), ulcerations (31%), tumors (11%), and small bowel diverticula (4%). Overall, 35 patients (52%) were found to have one or more lesions at IOE that were treated surgically and had no further bleeding. IOE, through a mid-small bowel enterotomy, has low morbidity and is effective in that it identified a treatable lesion in 74% of patients, which led to cure of bleeding in 52%. (J GASTROINTEST SURG2001;5:162-167.) KEY WORDS: Intraoperative, enteroscopy, endoscopy, obscure gastrointestinal bleeding Identifying the source of obscure gastrointestinal bleeding presents a formidable diagnostic challenge. Recently the American Gastroenterological Associa- tion defined obscure gastrointestinal bleeding as bleeding of unknown origin that persists or recurs af- ter a negative colonoscopy and/or upper endoscopy) Obscure bleeding can be further classified as overt, manifested by passage of visible blood, or occult, with positive fecal occult blood testing and iron deficiency anemia. Based on this definition of obscure gastroin- testinal bleeding, approximately 5% of all gastroin- testinal bleeding would be placed into this category. Push enteroscopy, often called extended upper en- doscopy because it visualizes 60 to 125 cm of the proximal jejunum, is able to identify lesions in up to 7 5 % of these patients. 2-5 Additional diagnostic proce- dures such as visceral angiography, radionuclide bleeding scans, and small bowel contrast studies can also identify the source of bleeding in another frac- tion of these patients with obscure gastrointestinal bleeding. Thus obscure bleeding after all nonsurgical methods of detection are exhausted probably repre- sents approximately 1% of all patients with gastroin- testinal bleeding. The "gold standard" for diagnosing the source of bleeding in this highly select, intensely evaluated group of patients is intraoperative en- teroscopy (IOE) performed at the time of exploratory celiotomy. Several series have demonstrated the effi- cacy of IOE in identifying a lesion responsible for ob- scure gastrointestinal bleeding in 70% to 100% of pa- tients. 5-9 However, diagnosis and treatment of these lesions cures bleeding in only 40% of these patients in ottr previous experience. 6 Using a large series of patients from a single insti- tution, our aims were (1) to determine the current ef- ficacy of IOE in finding lesions responsible for oh- From the Department of Surgery (M.L.K., D.E, and M.G.S.) and the Division of Gastroenterology and Hepatology (N.S.B., M.A.A., L.S.L., and K.K.W.), Mayo Clinic Rochester, Rochester,Minn. Presented at the Forty-First Annual Meeting of The Society for Surgeryof the AlimentaryTract, San Diego, Calif., May 21-24, 2000, and published as an abstract in Gastroenterology 118(Suppl 1):A1057,2000. Correspondence: Michael G. Sarr, M.D., Professor of Surgery, Chair, Division of Gastroenterologic and General Surgery, Gastroenter- ology Research Unit (AL 2-435), Mayo Clinic, 200 First Street SW, Rochester,MN 55905. 162