Intraductal applications of lidocaine attenuate the severity of post‐ERCP acute pancreatitis (1131.2)

Abstract

Endoscopic retrograde cholangiopancreatography (ERCP) is a procedure used to identify biliary duct obstruction. 5‐10% of patients, however, develop acute pancreatitis (AP). AP is a severe disorder of the exocrine pancreas marked by acinar inflammation and a rise in plasma amylase levels. Pancreatic secretions, including exocrine secretions (PES) are modulated by the vagus nerve, and microinjections of group II mGluR agonist APDC in the dorsal motor nucleus of the vagus (DMV) increase PES. In AP, however, DMV neurons are less sensitive to APDC. The aim was to develop a rat model of post ERCP‐pancreatitis to test the hypothesis that intraductal application of lidocaine prior to ERCP attenuates AP. The femoral vein and pancreatic duct of male SD rats were cannulated to collect whole blood sample and PES (at 10 minutes intervals: 30min baseline, treatment, and 90min post‐treatment), respectively. Similar to what occurs in ERCP, mechanical stimulation of the papilla of Vater increased plasma amylase and reduced the PES response to DMV microinjections of APDC (100pmoles/60nl; N=6). Injections of 200μL of lidocaine (N=5) and/or contrast dye (N=3, 3) into the pancreatic duct prior to papilla stimulation prevented the rise in plasma amylase and restored the APDC‐induced increase in PES. Intraductal lidocaine prior to ERCP may be a useful prophylactic treatment to lower the incidence of post‐ERCP AP. Group Amylase (U/L) Percent Change (%) PES to APDC Sham (n=3) 52.9 ± 16.7 33.4 ± 7.7 Papilla stimulation (n=6) 1012.2 ± 353.5 8.6 ± 6.4 Lidocaine (n=3) 263.0 ± 124.4 38.8 ± 7.7 Papilla stim. + Lidocaine (n=5) 235.1 ± 33.2 38.9 ± 8.1 Contrast dye (n=3) 155.6 ± 65.4 33.9 ± 2.9 Contrast dye + Lidocaine (n=3) 148.2 ± 46.4 27.9 ± 3.0 Grant Funding Source: APS Undergraduate Summer Research Fellowship & NSF‐1049618