Clinical utility of the patency capsule: a large volume center experience

BACKGROUND: In patients with suspected or known obstructive gastrointestinal pathology, the use of patency capsule (PC) aims to minimize the risk of subsequent retention of the endoscopic capsule. However, its clinical utility is not consensual. The aim was to evaluate the indications, results and safety profile of the PC. METHODS: Retrospective analysis of PCs (agile patency capsule) conducted between 2011 and 2015. Patency evaluation was performed after 30 hours, with radiological confirmation if PC was detected. RESULTS : We included 369 PCs, 54% female. The average age was 42 +/- 16 years. Main indications included suspected Crohn disease (CD) (45%), CD staging (32%), neoplastic diseases (9%), radic enteritis (3%), prior surgery (3%), NSAIDs enteropathy (2%) and anemia (2%). Before the exam 5% of patients were taking constipation-induced medications and 5% reported occlusive symptoms; 38% of patients had previous abdominal surgeries, most often ileal resection due to CD (24%); 42% of patients had previous imaging studies, revealing strictures in 20% and bowel dilation in 11%. Patency capsule was negative (patent gastrointestinal tract) in 73% of cases at 30h and 2% of PCs were fully recovered in the following days. Seven patients (2.5%) showed self-limiting occlusive symptoms during the procedure. All patients with negative PC subsequently performed capsule endoscopy with no cases of retention. History of occlusive symptoms (P=0.023) and strictures in imaging studies (P=0.029) were associated with the detection of the PC at 30 hours. CONCLUSIONS: PC is a safe and effective exam. Occlusive symptoms and imaging strictures were significantly associated with the retention. The retention rate was 25%, a similar result to that described in other series but higher than expected for the various indications, suggesting the importance of new research studies.