Endoscopic retrograde cholangiograms of the normal and post-cholecystectomy biliary tree

Influence of cholecystectomy on the flow dynamic pattern of bile in the extrahepatic bile duct: Assessment by cine-dynamic MRCP with spatially-selective IR pulse

PURPOSE

To evaluate the influence of cholecystectomy on the flow dynamic pattern of bile in the extrahepatic bile duct by using cine-dynamic MRCP with spatially-selective inversion-recovery (IR) pulse non-invasively.

MATERIALS AND METHODS

56 patients with cholecystectomy and 48 control subjects without cholecystectomy who underwent cine-dynamic MRCP with spatially-selective IR pulse at 1.5 T or 3 T (TR/TE, 4000 msec/500 msec; echo train spacing, 6.5 msec; echo train length, 172; section thickness, 50 mm; matrix, 320 × 320; field of view, 320 × 320 mm; bandwidth, 488 Hz; and inversion time, 2200 msec). In cine-dynamic MRCP, IR pulse with 20 mm width was placed on the common bile duct (CBD) to evaluate the movement of bile (antegrade and reversed bile flow). Cine-dynamic MRCP imaging was scanned every 15 s (imaging, 4 s; rest, 11 s) during 5 min to acquire a series of single-shot images (a total of 20 images). The frequency that antegrade or reversed bile flow was observed in the extrahepatic bile duct, and 5-point grading score based on the moving distance of antegrade or reversed bile flow were compared between the groups. Both groups were compared using the χ² and Mann-Whitney U tests (P < 0.05 considered significant).

RESULTS

Antegrade bile flow was observed more frequently in the cholecystectomy group than in the non-cholecystectomy group (5.1 times vs. 2.8 times, P = 0.008). Mean grading score of antegrade bile flow was significantly greater in the cholecystectomy group than in the non-cholecystectomy group (mean grade, 0.33 vs 0.21; P = 0.014). Regarding reversed bile flow, there were no significant differences in the frequency and grading score between cholecystectomy group and non-cholecystectomy group.

CONCLUSION

Antegrade bile flow was observed more frequently and predominantly in patients after cholecystectomy in cine-dynamic MRCP with spatially-selective IR pulse while reversed bile flow was observed equivalently.

Does cholecystectomy status influence the common bile duct diameter? A matched-pair analysis

The common bile duct (CBD) diameter is one factor that clinicians use when deciding on invasive evaluation for intra-ductal pathology, e.g., endoscopic retrograde cholangiopancreatography. Previous studies and gastrointestinal and radiological textbook authors report disparate interpretations. These inconsistent interpretations likely result from methodological limitations in prior studies. The purpose of this work is to primarily compare the CBD diameter among patients with and without prior cholecystectomy and secondarily to compare proximal and distal CBD measurements. Among 40 matched pairs, post-cholecystectomy patients had larger mean CBD diameters at proximal (7.0 vs. 5.4 mm; P < 0.001) and distal (5.9 vs. 4.6 mm; P < 0.001) sites. Post-cholecystectomy patients were also more likely to exceed the 6-mm cut point for proximal (80 vs. 28%; P < 0.001) or distal (58 vs. 20%; P = 0.003) measurements. Incidental radiographic detection of enlarged CBDs among post-cholecystectomy patients is common; therefore, clinicians should use clinical determinants to guide decisions about additional costly or potentially harmful evaluation for intraductal pathology.

ERCP findings and the role of endoscopic sphincterotomy in acute gallstone pancreatitis

A total of 131 patients with acute pancreatitis (of whom 100 had gallstones) underwent endoscopic retrograde cholangiopancreatography (ERCP) during the same hospital admission. Urgent ERCP (less than 72 h) was performed in 68 cases and early ERCP (3-30 days) in 63 cases; 47 had predicted severe attacks and 84 had predicted mild attacks (modified Glasgow criteria). The highest incidence of common bile duct stones occurred in those with predicted severe attacks and those who had urgent ERCP. Highly significant correlations were found between age and common bile duct and pancreatic duct diameters. Significant correlations were also found between the common bile duct and pancreatic duct (correcting for age) and between these and the admission serum bilirubin. The common bile duct diameter was greatest in those with common bile duct stones and predicted severe attacks. A considerably lower incidence of pancreatic duct filling occurred in those with predicted severe attacks and common bile duct stones; in predicted mild attacks the pancreatic duct diameter was greater in those with common bile duct stones. In gallstone patients complications were highest in those with predicted severe attacks but more significantly in those with common bile duct stones. Endoscopic sphincterotomy was undertaken in 37 patients with common bile duct stones without mortality. The overall complication rate in gallstone patients was 19 per cent and the mortality rate was 2 per cent. These findings suggest that common bile duct stones cause acute common bile duct and pancreatic duct obstruction and are closely associated with complications. Urgent ERCP for detection of common bile duct stones, and endoscopic sphincterotomy for treatment, is strongly recommended for patients with predicted severe attacks due to gallstones and should also be considered for others who fail to show clinical improvement.

The postcholecystectomy syndrome: bile ducts as pain trigger zone

Sixty-five non-icteric patients presumed to have the postcholecystectomy syndrome (PCS) were followed up for 4-13 years after their first endoscopic retrograde cholangiopancreatography (ERCP) examination, which gave normal findings. All patients, however, experienced severe pain on injection of only 1-2 ml of contrast medium over 5-10 sec into the common bile duct (CBD). Thirty-four of the 65 patients were found to have true PCS on long-term follow-up studies, whereas 31 of them had other diseases. A second ERCP also showed normal results, and the injection-related pain was preceded by an abnormal pressure rise in the CBD at manometry. The CBD acted like a pain trigger zone, and the pain reaction might be diagnostic in everyday clinical practice. In conclusion, ultrasonography is an adequate diagnostic method in non-obstructive PCS. Medical treatment is often successful. ERCP and interventional treatment should be reserved for patients with obstructive symptoms and for patients in whom all medical treatment has failed.

Bile duct calibre: the discrepancy between ultrasonic and retrograde cholangiographic measurement in the post-cholecystectomy patient

The discrepancy between bile duct measurements obtained by ultrasound and retrograde cholangiography in post-cholecystectomy patients was prospectively evaluated by performing real-time biliary tract sonography on 50 patients 2-3 h prior to endoscopic retrograde cholangiography (ERC). A significant discrepancy was detected (P less than 0.001) which was greatest in 14 patients shown by cholangiography to have duct dilatation without evidence of biliary tract disease (P much less than 0.001). Factors contributing to the discrepancy included: measurement of different regions of the duct by the two techniques, loss of duct wall elasticity producing a 'floppy duct' phenomenon, the capacity of the biliary tract for rapid spontaneous change in calibre, radiographic magnification and ultrasonic underestimation of duct diameter. The sonographic diameters were significantly correlated to the diameters measured by ERC (r = 0.73). Although ERC generally agreed with ultrasound in the diagnosis of duct dilatation (specificity 90%), there was significant disagreement between the two techniques in the detection of non-dilatation, dilated or 'dilatable' systems being missed by ultrasound in 11 out of 21 (52%) of cases in which they were found by ERC. Our results suggest that, in the investigation of the symptomatic post-cholecystectomy patient, direct comparison of bile duct size measured by ultrasound and ERC is of limited clinical value.