Current issues of ACP Journal Club are published in Annals of Internal Medicine


Diagnosis

Endoscopic ultrasonography was sensitive for choledocholithiasis

ACP J Club. 1994 Sept-Oct;121:50. doi:10.7326/ACPJC-1994-121-2-050


Source Citation

Amouyal P, Amouyal G, Lévy P, et al. Diagnosis of choledocholithiasis by endoscopic ultrasonography. Gastroenterology. 1994 Apr;106:1062-7.


Abstract

Objective

To determine the diagnostic accuracy of endoscopic ultrasonography (EUS) in patients with suspected choledocholithiasis.

Design

An operator-blinded comparison of EUS with ultrasound (US) and computed tomography (CT).

Setting

Tertiary care center in France.

Patients

62 consecutive patients (mean age 64 y, 53% women) had clinical or biochemical signs of choledocholithiasis meeting 1 of these criteria: epigastric or right upper quadrant pain with fever or jaundice; 1 or 2 of the preceding signs associated with elevated levels of serum alkaline phosphatase or serum [ggr ]-glutamyl transpeptidase or aminotransferase > 2 times the upper limit of normal; acute pancreatitis; or unexplained cholestasis defined by elevated levels of alkaline phosphatase and [ggr ]-glutamyl transpeptidase > 2 times normal. Exclusion criteria were heavy daily alcohol intake > 80 g, hepatotoxic drug intake, or serologic findings of acute hepatitis A or B.

Description of test and diagnostic standards

All patients had US, CT, and EUS scans within 72 hours of entering the study that were done by 3 different operators blinded to the results of the other tests. US and CT diagnostic criteria for choledocholithiasis were a hyperechoic structure within the common bile duct and a hyperdense, round-shaped image in the common bile duct surrounded by bile, respectively. For both tests, the common hepatic duct was considered enlarged if the diameter was > 7 mm. EUS was done by inserting a transducer into the second part of the duodenum while the patient was under general anesthesia. The diagnostic criterion for choledocholithiasis was the same as for US. Final diagnosis was established by surgery, choledochosopy, or follow-up.

Main outcome measures

Sensitivity and specificity for EUS, US, and CT.

Mail results

For the diagnosis of choledocholithiasis, the sensitivity and specificity for EUS, US, and CT are listed in the Table. Compared with US and CT, EUS was more sensitive (P < 0.001 and 0.002, respectively). The 3 methods did not differ for specificity. Sensitivity of EUS was as high as, or higher than, US and CT in patients with or without an enlarged common bile duct or stone diameter of < 1 cm.

Conclusion

Endoscopic ultrasound was more sensitive and at least as specific as ultrasound and computed tomography in diagnosing choledocholithiasis.

Source of funding: Not stated.

For article reprint: Dr. Pierre Bernades, Service de Gastroénterologie, Hôpital Beaujon, 92118 Clichy Cedex, France. FAX 33-1-42-70-37-84.


Table. Test characteristics for endoscopic ultrasonography, ultrasonography, and computed tomography for choledocholithiasis*

Test Sensitivity Specificity +LR -LR
Endoscopic ultrasonography 97% 100% 0.03
Ultrasonography 25% 100% 0.75
Computed tomography 75% 92% 9.4 0.27

*LRs defined in Glossary and calculated from data in article.


Commentary

Confirming choledocholithiasis remains a difficult clinical challenge. In this carefully designed study, Amouyal and colleagues show EUS to be a technique that offers considerable gains in sensitivity when compared with common noninvasive imaging. Improved diagnostic accuracy would decrease the need for operative cholangiography and avoid the morbidity, chiefly pancreatitis, of diagnostic endoscopic retrograde cholangiography (ERCP).

Several factors, however, may limit the widespread application of EUS for choledocholithiasis. EUS is much more cumbersome than US or CT; in this study, all patients had general anesthesia (not commonly used in the United States for ERCP or EUS). The effort required to learn and accurately interpret pancreatobiliary EUS is considerable; experience with up to 250 cases during a formal preceptorship year may be required (1, 2). The high cost of EUS technology further mandates careful scrutiny of outcome and cost-effectiveness issues (3).

These obstacles, coupled with the broad availability of ERCP, which, unlike EUS, also offers therapeutic capability, challenge the wisdom of substituting EUS for ERCP (or intraoperative cholangiography) in most instances. In fact, assuming their equivalent accuracy, EUS would be preferred only if it were clearly safer, better tolerated, and less expensive than cholangiography, the current gold standard. Even if these criteria were met, ERCP might still be preferable in patients at high risk for choledocholithiasis.

Glenn W.W. Gross, MD
Andrew K. Diehl, MD, MScUniversity of Texas Health Science CenterSan Antonio, Texas, USA


References

1. Hawes RH. You should become involved in EUS (pro). American Society for Gastrointestinal Endoscopy. 1994 Postgraduate Course syllabus.

2. Guidelines for Advanced Endoscopic Training. American Society for Gastrointestinal Endoscopy. Publication No. 1026, April 1994.

3. Wang KK, DiMagno EP. Endoscopic ultrasonography: high technology and cost containment. Gastroenterology. 1993;105:283-6.