Topical application of nitrates onto the papilla of Vater: manometric and clinical results.

BACKGROUND AND STUDY AIMS: Systemic administration of nitrates inhibits motility of the sphincter of Oddi (SO) but is hampered by a decrease of the arterial 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 (ERCP) 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 suspected 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 attempted with a 0.035" hydrophilic guide wire. In another trial, 16 biliary type III patients underwent endoscopic SO-manometry and received in a randomized 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 transpapillary 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 significantly between the groups. In addition, the pre-cut rate was nearly identical in the two groups. Topical GTN showed no significant influence on the 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 mmHg 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, whereas ISDN inhibited SO motility for > 5 minutes in all patients.

CONCLUSIONS: Both topically administered GTN and ISDN evoked a profound inhibition of SO motility, but the effect of ISDN was longer lasting than that of GTN. However, locally administered GTN did not facilitate selective bile-duct access during routine ERCP.