Investigation of the Sphincter of Oddi before, Immediately after and Six Weeks after Endoscopic Papillotomy

The sphincter of Oddi was investigated before, immediately after and 6 weeks after endoscopic sphincterotomy by endoscopic inspection, ERCP manometry, and by X-ray following retrograde cholangiography in 14 patients presenting with bile duct stones. The sphincter motility was normal before sphincterotomy. Following electrocautery no sphincter motility was noted, the sphincter baseline pressure showed considerable interindividual changes, and the length of the residual sphincter seemed to be only slightly reduced from 14.1 mm (before) to 10.9 mm. Despite this fact, bile duct concrements of more than 10 mm in diameter could be extracted without difficulty in all patients, confirming the adequacy of the sphincterotomy. Six weeks after sphincterotomy the sphincter length was 1.9 mm (0 to 7 mm) and in 6 patients the sphincter was completely incompetent, as demonstrated by the bile duct pressure (0 mmHg) and aerocholia, in the remaining 8 patients a small residual sphincter was able to maintain sphincter patency. We conclude that ERCP manometry cannot serve to confirm completeness of sphincterotomy immediately after electrocautery. But it would be possible to perform "semisphincterotomy" by assessing the sphincter length before cutting. Since sphincterotomy causes sphincter incompetence only in some patients, ERCP manometry would be a reliable aid for classifying the patients for follow-up studies.