729 Bile-Duct Dilatation After Laparotomy: A Potential Effect of Intestinal Hypomotility Vassilios Raptopoulo& Edward H. Smith1 Thomas 2 Wayne Silva3 Andrew Karellas1 Received March 13, 1986; accepted after revi- sion May 28, 1986. I Department of Radiology, University of Mas- sachusetts Medical Center, 55 Lake Ave. N., Worcester, MA 01605. Address reprint requests to V. Raptopoulos. 2 Present address: Department of Radiology, Health Sciences Center, St. John’s, Newfoundland, Canada Al B 326. of Surgery, University of Masse- chusetts Medical Center, 55 Lake Ave. N., Worces- ter,MA 01605. AJR 147:729-731, October 1986 0361 -803X/86/1474-0729 C American Roentgen Ray Society Dilatation of unobstructed extrahepatic bile ducts was observed in patients with conditions associated with intestinal hypomotility. For further investigation of this as- sociation, a prospective study was undertaken in which the common hepatic duct was measured in 15 patients before and I day after laparotomy, when all patients had postoperative paralytic ileus. A statistically significant (p < 0.01) increase in the mean diameter of the hepatic duct was observed postoperatively. When compared with the preoperative measurement, the mean diameter of the duct almost doubled, from 3.3 to 5.9 mm. This phenomenon may be due to persistent contraction of the sphincter of Oddi that occurs when intestinal hypomotility eliminates the stimuli for cholecystokinin re- lease. Diagnostic sonography, which can accurately assess the caliber of the common hepatic duct (CHD), is widely accepted as the screening method of choice for the detection of biliary obstruction [1 -3]. Although some controversy exists about the normal range of the internal diameter of the CHD, most investigators consider a measurement of 6 mm or smaller normal, and that of 7 mm or larger abnormal [3]. However, this distinction does not always correlate with biliary obstruction. Extrahepatic bile-duct obstruction may be present before the development of, or without, biliary dilatation [4, 5]. Conversely, patients without obstruction may show dilatation [3, 4, 6-8]. In some of these patients, previous obstruction, aging, and inflammation have adversely affected the elastic recoil and contractility of the extrahepatic duct wall [4, 8-1 0]. In others, no cause can be identified; often an incidental sonographic finding of extrahepatic biliary dilatation may start a battery of biochemical and imaging tests and, ultimately, surgical exploration. The fatty- meal stimulation test in such patients significantly improves diagnostic accuracy [8]. However, in some patients, administration of a fatty meal may be contraindi- cated, while in others the test provides inconclusive results. In our practice, we identified 33 patients with unexplained CHD dilatation, up to 15 mm. None of the causes of biliary dilatation mentioned earlier were present. The only common denominator we could identify was an association with a variety of conditions of intestinal hypomotility, including paralytic ileus resulting from miscellaneous abdominal and thoracic inflammatory processes or trauma. Several patients were receiving parenteral hyperalimentation or narcotics, or they had undergone previous vagotomy. In 21 patients, bile-duct obstruction was excluded by direct opacification, surgery, or autopsy. In the remaining 1 2, there was strong clinical and biochemical evidence to exclude obstruction. Follow-up sonograms showed nondilated CHD. These observations suggested association of intestinal hypomotility with extra- hepatic bile-duct dilatation. To study the problem more systematically, we studied prospectively 15 patients scheduled for elective major abdominal surgery to eval- uate CHD diameter changes during physiologic postoperative ileus. Downloaded from www.ajronline.org by 34.228.24.229 on 05/28/20 from IP address 34.228.24.229. Copyright ARRS. For personal use only; all rights reserved