Frequency and Clinical Outcomes of Retention and Factors Predicting Spontaneous Delayed Passage After Retention During Capsule Endoscopy: A Korean Nationwide Multicenter Study

Abstract

Background and aims: Although capsule endoscopy (CE) allows direct examination of the entire length of small bowel in a noninvasive manner, retention remains a major concern for physicians. The rates of retention, however, have been reported to vary widely from 0% to 21% because of the dissimilarity of indication for CE and study populations among investigations, and most of them were relatively small single center studies. Moreover, the predicting factors affecting the outcomes after retention remain unknown. The aims of this study were to investigate the frequency and clinical outcomes of capsule retention for various small bowel diseases, and to determine the predicting factors for the favorable outcomes after retention by a Korean multicenter study. Methods: By nationwide multi-center survey, we retrospectively reviewed the records of 1291 cases performed at institutions equipped with CE between February 2002 and July 2006 in Korea. For cases with capsule retention, clinical and procedural characteristics, and post-procedural outcomes were analyzed. Results: Capsule retention occurred in 2.8% of total cases (36/1291). The major causes of retention were Crohn's disease (47.2%), malignant tumors (13.9%), and intestinal tuberculosis (8.3%) in decreasing order in Korea. The retention rates for specific indications of disorders are as follows; 11.7% (7/60) in known or suspected Crohn's disease, 2.4% (15/629) in obscure gastrointestinal bleeding, 3.9% (9/229) in chronic unexplained abdominal pain, 1.7% (1/58) in chronic unexplained diarrhea, and 3.6% (1/28) in polyposis. Most of cases with retention (83.3%) were free from complications, but surgical or endoscopic interventions were performed for two thirds of the cases (21/36) to treat underlying diseases or retrieve caspule. In 11 (30.5%) of retention cases, capsule left patients spontaneously or with medical treatments of underlying diseases after retention. Regarding the predicting factors that affect clinical outcomes after retention, larger diameter of stricture area, and changing retention site on x-ray during follow-up were associated with spontaneous delayed passage without complications after retention. Conclusions: We identified the specific retention rates according to various indications of CE and small bowel diseases. Patients and physicians should be aware of the potential risks of retention when using CE in Crohn's disease, malignant tumors, or tuberculosis particularly in Korea. Outcomes of most retention cases were favorable and, moreover, we firstly documented some endoscopic and radiologic features which might predict spontaneous delayed passage after capsule retention.