Probe-based Confocal Laser Endomicroscopy in Double Balloon Enteroscopy

Background: Probe-based confocal laser endomicroscopy (pCLE) allows in-vivo assessment of the gastrointestinal mucosal architecture during ongoing endoscopy. We investigated the feasibility and safety of pCLE during double balloon enteroscopy (DBE). Methods: DBE was performed using the Fujinon EN-450P5. pCLE (Ceilvizio-GI (R), Mauna Kea Technologies) was performed after intravenous injection of 5-10 mL fluorescein 1% using a 1.8-mm probe (GastroFlex/ColoFlex Z-probe) at the deepest point of DBE insertion and in case of any pathological lesion. Primary outcome measure was technical success, defined as (i) successful advancement of the probe at the deepest DBE insertion and (ii) successful pCLE imaging of the intestinal mucosa. Secondary outcome was safety of the pCLE procedure. Results: 27 DBE procedures (14 antegrade) were performed in 16 patients. The mean depth of small bowel insertion was 255 cm for antegrade and 130 cm for retrograde DBE. Technical success of pCLE was achieved in 96.3% (antegrade 92.8%, retrograde 100%). One technical failure occurred (incomplete probe advancement). There were no adverse events related to the pCLE procedure. pCLE imaging of the small bowel mucosal architecture was possible in all cases. Pathological conditions within the small bowel such as loss of villi, crypt hyperplasia, advanced neoplasia, or increased blood flow due to inflammation tissue could be successful visualized. Conclusion: This study is the first to demonstrate successful and safe application of pCLE in the deep small bowel during double balloon enteroscopy. Further studies are needed to determine the clinical benefit of pCLE in the management of patients with small bowel diseases.