Background: Air cholangiogram has been used in patients with malignant hilar obstruction to reduce cholangitis after endoscopic retrograde cholangiopancreatography (ERCP). However, it still remains unclear whether CO2 could be used as an alternative for air cholangiography in such patients.
Objective: To investigate the effect of CO2 cholangiogram on post-ERCP complications.
Design: Prospective, randomized controlled study.
Setting: Tertiary care referral center.
Patients: 36 patients with Bismuth type II, III or IV were randomized into CO2 group or iodine contrast group (control group).
Intervention: Cholangiography was performed by injection of either CO2 or iodine contrast through a sphincterotome. One or two metal stents were placed.
Main outcome measures: Post-ERCP complications, length of hospital stay after ERCP, 1-month and 1-year mortality.
Result: There was no significant difference in age, gender, symptoms, liver function tests, type of tumor origin and Bismuth type between patients in CO2 and contrast groups (p > 0.05). Compared with one-stent placement, more volume of CO2 and longer operation time were observed when performing two-stent placement (both p < 0.05). The rate of cholangitis in CO2 group was significantly lower than that in control group (5.6% vs. 33.3%, p = 0.04). After ERCP, mean hospital stay time was shorter in CO2 group compared with control (p < 0.05). The difference of 1-month and 1-year mortality between two groups was not significant (both p > 0.05).
Conclusion: CO2 cholangiogram could be a safe method to visualize intrahepatic bile duct with low incidence of post-ERCP cholangitis, which could be considered for the patients with malignant hilar obstruction.