Time-limited fluoroscopy to reduce radiation exposure during ERCP: a prospective randomized trial

Background: Measures should be used to limit radiation exposure of the staff and patients during ERCP. Objective: To determine whether "time-limited fluoroscopy" reduces radiation exposure and fluoroscopy time (FT) compared with continuous fluoroscopy. Design: Prospective randomized trial. Setting: Tertiary academic medical center. Patients: Consecutive adult patients presenting for ERCP. Interventions: Subjects were randomized into 2 fluoroscopy setting groups: (1) time-limited, where x-ray exposure is limited to 3 seconds each time the foot-operated switch is depressed; (2) continuous, where x-ray exposure continues for as long as the switch is depressed. Main Outcomes Measurements: FT, patient, and procedure-related data were recorded. Radiation dosimetry badges were used to estimate cumulative exposure. Results: Ninety-nine procedures were performed in the time-limited group and 100 by using continuous fluoroscopy. The mean FT for time-limited fluoroscopy was 284.4 seconds (95% confidence interval [CI] 247.1-321.6) and for continuous fluoroscopy was 314 seconds (95% CI 265.6-362.4; P = .34). Longer FT was associated with moderate or difficult cannulation (P = .008), lithotripsy (P < .001), stent placement (P = .007), sphincterotomy (P < .001), and longer overall procedure length (P < 0.001). After controlling for confounding factors and interactions with a multiple linear regression model, time-limited fluoroscopy was associated with a 16.4% lower FT (P = .029). The average radiation dose was not amenable to multivariate analysis, and, therefore, no significant difference between groups was found. Limitations: Endoscopists were not blinded to the study group assignments. Conclusions: FT and radiation exposure are dependent upon numerous patient-, operator-, and procedu re related factors. This study found that, after controlling for the impact of confounding factors, time-limited fluoroscopy significantly decreases FTs.