Cap-assisted endoscopy increases ampulla of Vater visualization in high-risk patients

Background: Periampullary adenocarcinoma is a major clinical problem in high-risk patients including FAP population. A recent modification for visualizing the ampulla of Vater (AV) involves attaching a cap to the tip of the forward-viewing endoscope. Our aim was to compare the rates of complete visualization of AV using this cap-assisted endoscopy (CAE) approach to standard forward-viewing endoscopy (FVE). We also determined: (i) the rates of complications and additional sedation; (ii) the mean time required for duodenal examination; and (iii) the reproducibility among endoscopists performing this procedure.

Methods: We performed esophagogastroduodenoscopy for AV visualization in 102 > 18 years old using FVE followed by CAE. Video recordings were blinded and randomly selected for independent expert endoscopic evaluation.

Results: The complete visualization rate for AV was higher in CAE (97.0%) compared to FVE (51.0%) (p < 0.001). The additional doses of fentanyl, midazolam, and propofol required for CAE were 0.05, 1.9 and 36.3 mg. in 0.9, 24.5, and 77.5% patients, respectively. The mean time of duodenal examination for AV visualization was lower on CAE compared to FVE (1.41 vs. 1.95 min, p < 0.001). Scopolamine was used in 34 FVE and 24 CAE, with no association to AV complete visualization rates (p = 0.30 and p = 0.14). Three more ampullary adenomas were detected using CAE compared to FVE. Cap displacement occurred in one patient, and there was no observed adverse effect of the additional sedatives used. Kappa values for agreement between endoscopists ranged from 0.60 to 0.85.

Conclusions: CAE is feasible, reproducible and safe, with a higher success rate for complete visualization compared to FVE.

Trial registration: ClinicalTrials.gov , NCT02867826 , 16 August 2016.

Keywords: Ampulla of Vater; Ampullary adenoma; Ampullary carcinoma; Cap-assisted endoscopy; Forward-viewing endoscopy.