[An analysis of failure and safety profiles of capsule endoscopy].

Objective: To analyse the incidence of technical breakdown and clinical problem leading to the failure of capsule endoscopy examination and their influence on the diagnosis and to evaluate its feasibility and safety in special patient population.

Methods: A retrospective study of 300 consecutive patients referred to Renji Hospital for evaluation of suspected small bowel diseases between May 2002 and May 2006 was done. This included 300 consecutive patients. The median age of the patients was 51 y (range, 3 - 91 y). The young children group was defined as less than 10 years and the elderly group as more than 80 years. Technical problems were those related to the functioning of the equipment and clinical problems were those related to the patient. The incidence and the type of above-mentioned events and their influence on the diagnosis were analyzed. The safety and feasibility of the capsule endoscopy procedure were evaluated in the young children group, elderly group and patients with pacemakers, gastrectomy and Billroth II gastrojejunostomy, intestinal diverticula, Crohn's disease and polyp of small intestine.

Results: A total of 300 patients were involved. The incidence of technical problems was 1.3%, including one case of failing in activating the capsule, one case of failing in loading the data and two cases of short life of battery. Failure of diagnosis was encountered in two cases. The incidence of clinical problems was 33.0% (99 cases) and they caused 35.4% (35 cases) failure of diagnosis in the 99 cases. Three patients in the young children group were unable to swallow the capsule and endoscope-guided overtube technique was used with success in all. In the elderly group, the incidence of capsule retaining in the oesophagus and stomach was as high as 23.0%. In two patients with pacemaker no interference between pacemaker and capsule was detected. In two patients with Billroth II gastrojejunostomy no capsule retention occurred. In 16 patients with diverticulum, capsule retention occurred in 1 case (6.0%). In 42 patients with Crohn's disease, capsule retention occurred in 5 cases. No acute gastrointestinal obstruction was found in the 42 patients with Crohn's disease and in 5 patients with polyp of small intestine.

Conclusions: With capsule endoscopy technical mistakes causing failure were very rare. The majority of the clinical problems were related to the inability capsule to reach the colon during the recording time. Capsule endoscopy provides a well-tolerated, safe and effective tool to investigate the gastrointestinal diseases, especially some small bowel diseases.