Glyceryl trinitrate for prevention of post-ERCP pancreatitis and improve the rate of cannulation: a meta-analysis of prospective, randomized, controlled trials.

Background: Acute pancreatitis is the most common complication of diagnostic and therapeutic endoscopic retrograde cholangiopancreatography (ERCP). Several clinical trials used glyceryl trinitrate (GTN) to prevent the incidence of post-ERCP pancreatitis (PEP). However, the results were still controversial.

Objective: To conduct a meta-analysis of published, full-length, randomized controlled trials evaluating the effect of prophylactic GTN on the prevention of PEP, improve the rate of cannulation and the prevention of hyperamylasemia.

Methods: Literature searches were conducted using PubMed, EMBASE, The Cochrane Library and Web of Knowledge databases, using keywords "post-ERCP" and "pancreatitis" and limited in randomized controlled trials.

Results: Twelve RCTs involving 2649 patients were included. Eleven RCTs compared GTN with placebo for PEP prevention. Meta-analysis showed the overall incidence of PEP was significantly reduced by GTN treatment (RR 0.67; 95% CI, 0.52-0.87). Nevertheless, GTN administration did not decrease the incidence of moderate to severe PEP (RR 0.70; 95% CI, 0.42-1.15). Subgroup analyses revealed that GTN administered by sublingual was more effective than transdermal and topical in reducing the incidence of PEP. Besides, the prophylactic effect of GTN was far more obvious in the group of high PEP incidence than in the group of low PEP incidence. Additionally, the incidence of hyperamylasemia was significantly reduced by GTN treatment (RR 0.69; 95% CI, 0.54-0.90). No differences of the successful cannulation rate of bile ducts (RR 1.03; 95% CI, 0.99-1.06) attributable to GTN were observed.

Conclusion: Prophylactic use of GTN reduced the overall incidence of PEP and hyperamylasemia. However, GTN was not helpful for the severity of PEP and the rate of cannulation.