Sphincter of Oddi pressure in chagasic patients with megaesophagus

Autonomic denervation is found throughout the entire length of the digestive tract in Chagas' disease. Anatomic evidence of myenteric ganglia reduction in chagasic gallbladders has been noted; however, the sphincter of Oddi has not been studied. The purpose of this study is twofold: first, to determine sphincter of Oddi pressure in 11 patients with chronic Chagas' disease and megaesophagus, and to compare the results with those obtained in 27 control subjects; and second, to evaluate the effect of cholecystokinin-octapeptide on sphincter of Oddi pressure in both groups of patients. Sphincter of Oddi pressure was recorded continuously via an endoscopically placed triple-lumen catheter inserted into the papilla and directed into the common bile duct. Basal sphincter of Oddi pressure was 12.9 +/- 1.1 mmHg in controls as compared with 44.9 +/- 4.7 mmHg in chagasics with megaesophagus. Mean common bile duct/duodenum gradient pressure was 4.1 +/- 2.4 mmHg in controls as compared with 13.1 +/- 2.7 mmHg in chagasics. Amplitude of sphincter of Oddi phasic contractions in the control group was 102.4 +/- 5.5 mmHg as compared with 140.5 +/- 9.2 mmHg in the chagasic group. Pulse dose of intravenous cholecystokinin-octapeptide produced a decrease of basal sphincter of Oddi pressure with inhibition of sphincter of Oddi phasic contractions in both chagasic and control patients. In chagasic patients, a neural abnormality in the sphincter of Oddi segment could explain the observed high basal pressure and high amplitude of phasic contractions. Chagasic patients with sphincter of Oddi pressure abnormalities, demonstrating sphincter of Oddi relaxation after cholecystokinin-octapeptide, may have neural impairment limited to preganglionic fibers, while the postganglionic inhibitory nerves remain at least partially intact.