The objective of the present study was to perform a meta-analysis of all available studies on the effect of prophylactic ulinastatin administration on preventing post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP). The PubMed, Web of Knowledge and Chinese National Knowledge Infrastructure databases were searched to identify all relevant studies published in English or Chinese prior to April 2016. Cochrane Review Manager was used to calculate the pooled risk ratio (RR) and 95% confidence interval (CI) to determine the effect of prophylactic ulinastatin on PEP, post-ERCP hyperamylasemia (PEHA) and post-ERCP abdominal pain. The analysis revealed that prophylactic ulinastatin administration significantly reduced the PEP risk (RR=0.49; 95% CI: 0.33-0.74; P=0.0006; I2=24); however, such significant risk reduction occurred only in patients with low or average risk for PEP and high-dosage ulinastatin (150,000 or 200,000 U) administration, and when the ulinastatin administration began prior to or during ERCP. Pre-ERCP ulinastatin administration alone without additional administration after ERCP was sufficient. Prophylactic ulinastatin also significantly reduced the PEHA risk (RR=0.68; 95% CI: 0.56-0.83; P=0.0001; I2=19) and marginally reduced the incidence of post-ERCP abdominal pain (RR=0.67; 95% CI: 0.45-1.00; P=0.05; I2=67). In conclusion, prophylactic ulinastatin administration significantly reduced the risk of PEP in patients with low or average risk for PEP when administered at a high dosage prior to or during ERCP. High-quality studies, particularly on high-risk patients, are warranted.
Keywords: abdominal pain; hyperamylasemia; meta-analysis; post-endoscopic retrograde cholangiopancreatography pancreatitis; ulinastatin.