Effect of CO₂ cholangiography on post-ERCP cholangitis in patients with unresectable malignant hilar obstruction – a prospective, randomized controlled study

Abstract

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.

Key Words::

• CO₂
• cholangiogram
• malignant hilar obstruction
• metal stent
• ERCP

Acknowledgments

We thank Subesh Kumar Dahal for his help in the manuscript preparation. The work was supported by National Natural Science Foundation of China (81101689 and 81172288), Science Foundation for excellent doctoral thesis of Ministry of Education (200975) to Yanglin Pan and Technology Innovation Foundation of Xijing Hospital for Xuegang Guo.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.