CO2 Cholangiography Reduce Cholangitis Risk in Patients with Bismuth Type IV Hilar Biliary Obstruction during ERCP

Backgrounds: Endoscopic palliation in hilar obstruction requires endoscopic retrograde cholangiopancreatography (ERCP), whereas cholangitis could be induced by contrast injection. Post ERCP cholangitis risk is particularly high in Bismuth type IV hilar obstruction, and the risk is further increased if the contrast could not be drained. The aim of this study is to evaluate the cholangitis risks associated with contrast agent, air and CO 2 injection in type IV hilar lesions. Methods : The authors retrospectively evaluated the utility of contrast, air and CO 2 cholangiography in consecutive 70 patients with type IV hilar obstruction. The patients were divided into 3 groups based on the agent used: A) contrast (n=22), B) air (n=18), and C) CO 2 (n=30). Prior to ERCP, MRCP was obtained in all patients to guide endoscopic intervention. Results : At baseline, there was no significant difference in patient’s age, gender, symptoms, liver function tests between different groups ( p ＞0.05). The complication rates in group B and C were significantly lower than that in group A (27.8% and 26.7% versus 63.6%, p ＜0.05). Except cholangitis risk ( p ＜0.05), no significant difference was found in post ERCP pancreatitis and bleeding risks (both p ＞0.05) between the 3 groups. After ERCP, the mean hospital stay duration was shorter in group B and C compared with group A ( p ＜0.05). However, the difference of one month mortality between 3 groups was not significant ( p ＞0.05). There was no significant difference between group B and C in primary end points. Conclusions : CO 2 cholangiography based ERCP is safer and should be utilized to reduce the risk of post-ERCP cholangitis in typer IV hilar obstruction.