Toshiyuki Aizawa

Characterization of biliary strictures using intraductal ultrasonography: comparison with percutaneous cholangioscopic biopsy.

BACKGROUND We determined the accuracy of intraductal ultrasonography (IDUS) in distinguishing between bile duct cancer and benign bile duct disease. METHODS Patients (n=42) who required bile duct biopsy using percutaneous transhepatic cholangioscopy (PTCS) to evaluate bile duct strictures or filling defects were studied. A thin-caliber ultrasonic probe (2.0 mm diameter and 20 MHz frequency) was inserted into the bile duct, and its images were prospectively reviewed before PTCS. RESULTS Disruption of the bile duct wall structure, seen on IDUS, was associated with malignancy in 25 of 26 patients. When IDUS demonstrated a lesion with normal bile duct structure, six of nine patients were found to have no malignancy. IDUS demonstrated no intraductal lesion in seven patients, and bile duct biopsy also did not indicate cancer in any of these patients. The accuracy, sensitivity, and specificity of IDUS for diagnosing bile duct cancer were 76%, 89%, and 50%, respectively. When used in tandem with IDUS, the sensitivity of bile cytology (64%) and PTCS (93%) improved to 96% and 100%, respectively. CONCLUSIONS The accuracy of IDUS for diagnosing bile duct cancer was less than that of PTCS (95%). However, the sensitivity for bile cytology, or bile duct biopsy improved when performed in combination with IDUS.

Influence of biliary drainage catheter on bile duct wall thickness as measured by intraductal ultrasonography

OBJECTIVE To determine the influence of biliary drainage catheter placement on bile duct wall thickness, we performed intraductal ultrasonography (IDUS) in patients before and after biliary drainage. METHODS Patients underwent IDUS before and after either short-term (n = 9, 6 to 8 days) or long-term (n = 9, 14 to 35 days) biliary drainage using a thin (2.0 mm diameter), 20 MHz probe inserted by means of a transpapillary route or a percutaneous tract. The bile duct wall thickness (mean +/- standard deviation) was retrospectively measured at the upper portion of the common hepatic duct. RESULTS The bile duct wall thickness increased from 0.8+/-0.4 mm (predrainage) to 2.0+/-1.6 mm (post-drainage) in the long-term group (p < 0.001) but was not significantly increased in the short-term group. CONCLUSIONS The bile duct wall thickness as measured on IDUS appears to be increased after placement of biliary drainage catheters.

Bile duct wall thickness measured by intraductal US in patients who have not undergone previous biliary drainage

BACKGROUND We investigated the bile duct wall thickness measured on intraductal US in patients who had not undergone biliary drainage, with special attention to the influence of cancer at the distal bile duct, bile duct stones, obstructive jaundice, longitudinal cancer extension, and primary sclerosing cholangitis on wall thickness. METHODS The study included 183 patients. Patients who had undergone previous biliary drainage were excluded. Intraductal US was performed by the transpapillary route with use of a thin-caliber ultrasonic probe (2.0 mm diameter, 20 MHz frequency). The bile duct wall thickness (width of the inside hypoechoic layer) was retrospectively measured on US images. RESULTS Bile duct wall thicknesses of the common hepatic duct for the control group (n = 95), cancer at the distal bile duct group (n = 9), bile duct stone group (n = 56), and obstructive jaundice group (n = 17) were 0.6 +/- 0.3 mm (mean +/- SD), 0.8 +/- 0.5 mm, 0.8 +/- 0.6 mm, and 0.8 +/- 0. 5 mm, respectively. No significant differences (p > 0.05) were found between them. However, wall thickness for the cancer extension to the common hepatic duct group (n = 4, 2.0 +/- 0.4 mm) and sclerosing cholangitis group (n = 2, 2.5 +/- 0.4 mm) were significantly greater than in the other groups (p < 0.005). CONCLUSIONS In patients who have not undergone previous biliary drainage, the bile duct wall thickness was not thicker in patients with obstructive jaundice. However, the duct wall was significantly thicker in patients with either longitudinal cancer extension or primary sclerosing cholangitis compared with that of other groups.

Assessment of residual bile duct stones with use of intraductal US during endoscopic balloon sphincteroplasty: comparison with balloon cholangiography

BACKGROUND We sought to determine the utility of intraductal ultrasonography (IDUS) in detecting residual bile duct stones during endoscopic balloon sphincteroplasty. METHODS Eighty-one consecutive patients with bile duct stones who underwent IDUS during endoscopic balloon sphincteroplasty were studied. IDUS was performed with a thin-caliber ultrasonic probe (diameter 2.0 mm, frequency 20 MHz) by a transpapillary route after stone extraction. When IDUS or balloon-retrograde cholangiography suggested residual stones, the bile duct was cleared again with a Dormia basket. Extraction of the stones was confirmed by direct duodenoscopic visualization. Videotapes of IDUS and cholangiograms were reviewed retrospectively without knowledge of the results of other diagnostic modalities. RESULTS In 27 of 81 patients (33%), IDUS detected small residual stones not seen on cholangiography. When stones were fragmented with mechanical lithotripsy, the accuracy of IDUS in detecting small residual stones was significantly greater than that of balloon-endoscopic retrograde cholangiography (95% vs 50%, p < 0. 001). When the bile duct was greater than 10 mm in diameter, the accuracy of IDUS in detecting small residual stones was significantly greater than that of cholangiography (92% vs. 56%, p < 0.001). CONCLUSIONS IDUS is useful for detecting small residual bile duct stones during endoscopic balloon sphincteroplasty when stones are fragmented by mechanical lithotripsy or when there is evidence of a dilated bile duct (>10 mm).

Limitation of cholangiography in assessing longitudinal spread of extrahepatic bile duct carcinoma to the hepatic side.

Background: Preoperative assessment of longitudinal spread of bile duct carcinoma (BDC) to the hepatic side remains a difficult problem for diagnostic imaging.

Assessment of the course and variations of the hepatic artery in bile duct cancer by intraductal ultrasonography

BACKGROUND We evaluated the course and variations of the hepatic artery in bile duct cancer using intraductal ultrasonography (IDUS). METHODS IDUS was used to demonstrate the course of the hepatic artery preoperatively in 20 patients with extrahepatic bile duct cancer, and the image was compared with angiographic and surgical findings. RESULTS IDUS was able to assess tumor invasion to the main branch of the right hepatic artery in all cases. However, it demonstrated only three cases in the left hepatic artery and four cases in the proper hepatic artery. When the hepatic artery indicated re-entry or bifurcation on the IDUS image, the proximal portion of re-entry or bifurcation was established as the proper hepatic artery, but when it showed neither re-entry nor bifurcation it was established as the right hepatic artery. CONCLUSIONS IDUS demonstrated the main branch of the right hepatic artery in all cases, but was not useful for demonstration of the left and proper hepatic arteries. Correct assessment of re-entry and bifurcation was essential on IDUS images for making the distinction between the right hepatic artery and the proper hepatic artery.

Prognostic Factors for Recurrence of Bile Duct Stones after Endoscopic Treatment by Sphincter Dilation

BACKGROUND The long-term outcome for patients after endoscopic sphincter of Oddi dilation is poorly documented. This study investigates the recurrence rate for bile duct stones in patients followed for 1 year or more after endoscopic sphincter dilation and stone extraction, and assessed prognostic factors associated with recurrence of ductal calculi. METHODS A total of 169 patients with bile duct stones were treated with endoscopic sphincter dilation between July 1998 and August 2001. Follow-up studies consisted of periodic biochemical tests and out-patient evaluations with endoscopic retrograde cholangiography or magnetic resonance cholangiography performed when follow-up exceeded 1 year. Putative risk factors for stone recurrence included gender, age, stone size and number, associated peripapillary diverticulum, gallbladder status, color of bile duct stones, and bile duct diameter. Statistical analysis consisted of both a Kaplan-Meier estimation and a multivariate Cox regression model. RESULTS Complete stone clearance was achieved in 162 (95.8%) patients, of whom 151 were followed (13 patients died from unrelated disorders). Mean follow-up was 23 months. Stone recurrence was documented in 13 patients. Patients with dilated bile duct or peripapillary diverticulum were at high risk for recurrence. CONCLUSIONS The interval between treatment of bile duct stones by endoscopic sphincter dilation and the recurrence of biliary calculi is relatively short. Bile duct size and peripapillary diverticula are risk factors for early recurrence.

Preoperative assessment of congenital bile duct dilatation using intraductal US.

BACKGROUND Although congenital bile duct dilatation is frequently associated with biliary tract cancer, conventional cholangiography often does not demonstrate small ductal tumors. This is the first prospective study of the value of intraductal ultrasonography (US) in the examination of the extrahepatic bile ducts in patients with congenital bile duct dilatation. METHODS Intraductal US via a transpapillary route was used in consecutive patients with congenital bile duct dilatation. A 2.0 mm diameter, 20 MHz frequency catheter probe was used. The images were correlated with the results of histologic examination of the resection specimens. RESULTS Intraductal US was performed successfully via the transpapillary route in 8 of 10 patients. In the other 2 patients, the percutaneous transhepatic route was used. In the 6 patients with cylindrical dilatation, intraductal US demonstrated the entire extrahepatic bile duct. In 1 patient, it showed a bile duct cancer not demonstrated by cholangiography. In 2 of the 4 patients with cystic dilatation, intraductal US did not demonstrate the entire extrahepatic bile duct because of the low penetration depth of the probe. Percutaneous transhepatic cholangioscopy was required in these patients. CONCLUSIONS Intraductal US is useful for demonstrating cancers in the extrahepatic bile ducts in patients with congenital cylindrical ductal dilatation.

Pancreatic arteriovenous malformation with duodenal ulcer. Demonstration by color Doppler ultrasonography.

SummaryWe report the color Doppler ultrasonography features of arteriovenous malformation (AVM) of the pancreas, a very rare disease. The patient was a 52-year-old man with congenital AVM of the pancreas and a duodenal ulcer that had been resistant to medication. Endoscopic color Doppler ultrasonography (color Doppler EUS) revealed many abnormal color signals showing pulsatile wave form at the portion of the duodenal wall involving the duodenal ulcer. Extracorporeal color Doppler ultrasonography revealed a mosaic-like color signal, caused by turbulent flow, in the portal trunk. Angiography demonstrated a vascular network with extensive proliferation at the pancreatic head and early portal filling. It is possible that the pancreatic AVM had caused the duodenal ulcer. Color Doppler EUS can be a useful modality for detection of vessel abnormalities of the gastrointestinal tract.

Temporary pancreatic duct stenting to prevent pancreatitis induced by endoscopic sphincter dilation

Abstract: To investigate whether prophylactic temporary stenting of the main pancreatic duct would decrease the incidence of pancreatitis after endoscopic sphincter dilation (ESD), we conducted this procedure subsequent to ESD in 13 patients who had common bile duct stones. After ESD and extraction of stones, a stent was placed into the pancreatic duct across the papilla of Vater. The stent was removed endoscopically three days later. Stents were successfully placed in 12 (92.3%) patients. In 11 of the patients, there was no significant elevation of serum amylase values before and after the procedure. The remaining patient, whose stent was identified as occluded, demonstrated elevated serum amylase values. However, there were no other procedure‐related complications. Although our report was only limited to 12 cases, our results suggest that temporary pancreatic stenting may help prevent postprocedual pancreatitis. (Dig Endosc 1999; 11:32–36)