Topical application of nitrates onto the papilla of vater: Manometric and clinical results

Background and Study Aims: Systemic administration of nitrates inhibits mot ility of the sphincter of Oddi (SO) but is hampered by a decrease of the ar terial blood pressure. We evaluate whether topical application of glyceril trinitrate (GTN) onto the papilla can facilitate cannulation of the common bile duct during routine endoscopic retrograde cholangiopancreatography (ER CP) and compare the effect of topical GTN with that of isosorbide dinitrate (ISDN) on SO motility. Patients and Methods: A total of 80 patients undergoing routine ERCP for su spected biliary obstruction received topical application of either saline ( n = 40) or 10 mg of GTN (n = 40) onto the papilla of Vater in a randomized, double-blind fashion. Thereafter, selective bile-duct cannulation was atte mpted with a 0.035" hydrophilic guide wire. In another trial, 16 biliary ty pe lll patients underwent endoscopic SO-manometry and received in a randomi zed fashion either 10 mg of GTN (n = 8) or 10 mg of ISDN (n = 8) which was infused topically onto the papilla via the manometric catheter, Thereafter, the manometric recording was continued for a further 5 minutes. Results: A spontaneous opening of the papilla with concurrent transpapillar y bile flow was observed in 24/40 patients after topical GTN, and in only 8 /40 patients after topical saline (P <0.01), However, neither the number of cannulation attempts nor the time until successful cannulation differed si gnificantly between the groups. In addition, the pre-cut rate was nearly id entical in the two groups. Topical GTN showed no significant influence on t he mean arterial blood pressure. The SO-baseline pressure was significantly lowered by topical GTN (28.2 +/- 12.9 mm Hg before ISDN vs. 22.5 +/- 13.7 mm Hg after P <0.01), The phasic SO motility was also strongly inhibited by both drugs. However, the effect of GTN completely wanes after 3 minutes, w hereas ISDN inhibited SO motility for >5 minutes in all patients. Conclusions: Both topically administered GTN and ISDN evoked a profound inh ibition of SO motility, but the effect of ISDN was longer lasting than that of GTN, However, locally administered GTN did not facilitate selective bil e-duct access during routine ERCP.