Biliary, Pancreatic, and Sphincter of Oddi Electrical and Mechanical Signals Recorded During ERCP THOMAS L. ABELL, MD, ROBERT F. WERKMAN, MD, BABAJIDE O. FAMILONI, PhD, WAGDY BAGGOUS, MD, DANIEL MASSIE, MD, and SANTIAGO VERA, MD Measure ments of biliary tract motility have focuse d on radiologic and pressure measurements to quantify biliary motility rather than measurements of electrical activity of the biliary tract. We previously reported the recording of biliary electrical signals during ERCP and now report on the continue d development and validation of a system to measure biliary tract electrical activity as well as biliary mechanical activity. In 26 patients presenting with a variety of clinical indications, we recorded measurements of electrical activity from the common bile duct sphincter (16 patients), pancreatic duct sphincter (eight patients), and/or sphincter of Oddi (eight patients). Electrical recordings were performed with a specially modi®ed ERCP catheter, using two circular electrodes as well as a custom catheter that measured both electrical and mechanical activity. Electrical activity of the biliary tract was successfully recorded in 25 of 26 patients (96% ), including the common bile duct sphincter (16 patients, 62% ), pancreatic duct sphincter (eight patients, 31% ) and sphincter of Oddi (eight patients, 31% ). Along with the electrical recordings, common bile duct sphincter mechanical activity was recorded in 12 patients (67% ), pancreatic duct sphincter mechanical activity in six patients (33% ), and sphincter of Oddi mechanical activity in six patients (33% ). Frequency analysis of electrical signals revealed a mean frequency (cycles/min) of 4.7 6 0.5 in the common bile duct sphincter, 4.1 6 0.6 in the pancreatic duct sphincter, and 4.9 6 0.7 in the sphincter of Oddi. Phasic mechanical frequency in cycles per minute was recorded at a frequency of 4.8 6 0.5 in common bile duct sphincter, 4.0 6 0.6 in pancreatic duct sphincter, and 5.3 6 0.9 in sphincte r of Oddi. Tonic pressure (averaged 12.1 6 1.5 mm Hg) in common bile duct sphincter, 12.4 6 1.4 mm Hg in pancreatic duct sphincter, and 15.0 6 5.1 mm Hg in sphincter of Oddi. Analysis of wave form propagations (noted as percentage antegrade, retrograde, or indeterminant) revealed 50% antegrade, 23% retrograde, and 27% indeter- minant). One patient was recorded on two occasions via ERCP; the same patient had an intraoperative recording. All three recordings showed similarities. We conclude that mea- surements of biliary, pancreatic, and sphincter of Oddi electrical and mechanical activity are feasible and can be done as part of ERCP. There was good correlation between biliary tract electrical and mechanical events and different wave form characteristics were noted for different parts of the biliary tree. Further studies are warranted to evaluate the potential usefulness of measurement of biliary tract electrical activity, and to con®rm its correlation with mechanical events in the pancreato-biliary tree. KEY WORDS: biliary tract motility; electrical activity; ERCP; mechanical activity. Digestive Diseases and Sciences, Vol. 43, No. 3 (March 1998), pp. 540±546 540 Digestive Diseases and Sciences, Vol. 43, No. 3 (March 1998) 0163-2116/98/0300-0540$15.00/0 Ñ 1998 Plenum Publishing Corporation