Preliminary experience using endoscopic ultrasonography in the diagnosis of choledocholithiasis

Predicting common bile duct stones by non-invasive parameters

BACKGROUND

Common bile duct (CBD) stone affect about 10% of patients with symptomatic cholelithiasis. The American Society for Gastrointestinal Endoscopy (ASGE) published a strategy in 2010 for managing patients with suspected choledocholithiasis. This study aimed to assess the performance of different clinical parameters in predicting CBD stones.

METHODS

A total of 344 patients suspected to suffer from CBD stone and referred to endoscopic ultrasound (EUS) were included. Parameters were collected and their prediction power for CBD stones was assessed.

RESULTS

One hundred and sixty-seven patients without CBD stone according to EUS (group A) were compared to 177 patients with CBD stones (group B). Several predictive factors for CBD stone were identified on univariate analysis. In multivariate regression analysis, CBD width by US (OR = 1.224, 95% CI: 1.073-1.359; P = 0.0026), age (OR = 1.023, 95% CI: 1.011-1.035; P = 0.0002) and gamma glutamyl transferase (GGT) level (OR = 1.001, 95% CI: 1.000-1.002; P = 0.0018) were significantly correlated with CBD stone, with receiver operator characteristics (ROC) of 0.7259. We generated a diagnostic equation [age (yr) × 0.1 + CBD width (mm) by US × 1 + GGT (U/L) × 0.005] to predict CBD stone with ROC of 0.7287.

CONCLUSIONS

We suggest this score as a very strong predictor for CBD stones, and to reduce the strength of total bilirubin and transaminases as predictors.

Evaluation of residual bile duct stones by peroral cholangioscopy in comparison with balloon-cholangiography

We evaluated the usefulness of peroral cholangioscopy (POCS) for residual bile duct stones in patients with complete bile duct clearance confirmed by balloon-occluded cholangiography. A total of 108 patients with common bile duct stones who underwent POCS after extraction of stones via endoscopic sphincterotomy, resulting in complete bile duct extraction confirmed by balloon-occluded cholangiography, were retrospectively evaluated. For the treatment of difficult stones, stones were fragmented by mechanical lithotripsy (ML) or electrohydraulic lithotripsy (EHL). In 26 patients (24%), residual stones were detected with POCS in the lower bile duct. In patients with residual stones, large bile duct stones, juxtapapillary diverticulum, and use of ML or EHL were significantly related to residual stones (P < 0.05). Although a prospective study is necessary to clarify whether this procedure is appropriate in aspects of cost and benefits, POCS appears to be a useful diagnostic tool for confirming complete extraction of bile duct stones. POCS may be useful, particularly when lithotripsy using ML or EHL is performed and a large pneumobilia exists in the bile duct.

Systematic review of endoscopic ultrasonography versus endoscopic retrograde cholangiopancreatography for suspected choledocholithiasis

BACKGROUND

Endoscopic ultrasonography (EUS) has emerged as an accurate diagnostic alternative to endoscopic retrograde cholangiopancreatography (ERCP). The aim of this study was to perform a systematic review of all randomized controlled trials of EUS-guided ERCP versus ERCP alone in patients with suspected choledocholithiasis.

METHODS

The search for eligible studies was carried out using the MEDLINE, Cochrane Central Register of Controlled Trials, and Science Citation Index electronic databases. Meta-analysis was conducted using a random-effects model.

RESULTS

Four trials containing 213 patients randomized to EUS-guided ERCP and 210 to ERCP alone were selected. In the EUS-guided ERCP group, ERCP was avoided in 143 patients (67.1 per cent) when EUS did not detect choledocholithiasis. The use of EUS significantly reduced the risk of overall complications (relative risk 0.35 (95 per cent confidence interval (c.i.) 0.20 to 0.62); P < 0.001) and post-ERCP acute pancreatitis (relative risk 0.21 (95 per cent c.i. 0.06 to 0.83); P = 0.030).

CONCLUSION

By performing EUS first, ERCP may be safely avoided in two-thirds of patients with common bile duct stones. Application of EUS in the selection of patients for therapeutic ERCP significantly reduces the complication rate.

EUS: a meta-analysis of test performance in suspected choledocholithiasis

BACKGROUND

EUS has been proposed as a less invasive means of diagnosing choledocholithiasis and may eliminate the need for ERCP and its associated risks. The literature pertaining to EUS for the diagnosis of choledocholithiasis reports widely varying sensitivities and specificities.

OBJECTIVE

To more precisely estimate the diagnostic accuracy of EUS in suspected choledocholithiasis.

DESIGN

MEDLINE and EMBASE databases were used to identify prospective cohort studies in which the results of EUS were compared with the results of an acceptable criterion standard, including ERCP, intraoperative cholangiography, or surgical exploration. Two independent reviewers extracted standardized data and assessed trial quality. A random effects model was used to estimate the sensitivity, specificity, likelihood, and diagnostic odds ratio (DOR), and a summary receiver operating characteristic curve was constructed. All predefined potential sources of heterogeneity were explored by subgroup analysis and meta-regression.

PATIENTS

A total of 2673 patients with suspected choledocholithiasis were reported in 27 studies that satisfied the inclusion criteria.

RESULTS

EUS had a high overall pooled sensitivity of 0.94 (95% CI, 0.93-0.96), a specificity of 0.95 (95% CI, 0.94-0.96), and an area under the curve of 0.98. Three variables appeared to yield a higher DOR: a higher disease prevalence, an adequate time interval between index test and criterion standards, and the presence of verification bias.

LIMITATIONS

Misclassification of patients by imperfect criterion standards could potentially underestimate the performance of an EUS.

CONCLUSIONS

An EUS is a noninvasive test, with excellent overall sensitivity and specificity for diagnosing choledocholithiasis. An EUS should, therefore, be used to select patients for a therapeutic ERCP to minimize the risk of complications associated with unnecessary diagnostic ERCP.

EUS vs MRCP for detection of choledocholithiasis

BACKGROUND

Numerous published studies have shown the high diagnostic performance of both EUS and MRCP compared with ERCP for the detection of choledocholithiasis.

DESIGN

We undertook a systematic review of all published randomized, prospective trials that compared EUS with MRCP with the primary aim being to compare the overall diagnostic accuracy for the detection of choledocholithiasis in patients with suspected biliary disease.

METHODS

A MEDLINE review was performed. We identified 5 randomized, prospective, blinded trials comparing MRCP and EUS for the detection of choledocholithiasis, with subsequent ERCP or intraoperative cholangiography as a criterion standard. The study-specific variables for EUS and MRCP for choledocholithiasis were calculated from the data, and analyses were performed by using aggregated variables (sensitivity, specificity, positive and negative predictive values, and likelihood ratios).

RESULTS

The pooled data set consisted of 301 patients. The aggregated sensitivities of EUS and MRCP for the detection of choledocholithiasis were 0.93 and 0.85, respectively, whereas their specificities were 0.96 and 0.93, respectively. The aggregated positive predictive values for EUS and MRCP were 0.93 and 0.87, respectively, with the corresponding negative predictive values of 0.96 and 0.92, respectively. Positive likelihood ratios were >10 for both tests, and corresponding negative likelihood ratios approached 0.10 for both tests. No statistically significant differences between EUS and MRCP were found in our analysis.

CONCLUSIONS

EUS and MRCP have high diagnostic performance overall. Our analysis showed no statistically significant difference between the modalities. We recommend taking into consideration other factors, such as resource availability, experience, and cost considerations in deciding between these 2 tests.

Endoscopic ultrasonography

Endoscopic ultrasound (EUS) was introduced in the early 1980s in an attempt to improve sonographic imaging of the pancreas. Its uses have been expanded to include examination of the upper and lower gastrointestinal tracts, hepatobiliary and portal systems,and the anal sphincter; diagnosis and staging of esophageal, gastric,and pancreaticobiliary tumors; and evaluation of mediastinal nodes in lung cancer. Although EUS has its limitations and is greatly dependent on operator skill, it has wide-ranging interventional and therapeutic applications that can be expected to increase in the future with technologic advances and greater educational opportunities for physicians.

Endosonography with linear array instead of endoscopic retrograde cholangiography as the diagnostic tool in patients with moderate suspicion of common bile duct stones

AIM: To evaluate the diagnostic efficiency of endoscopic ultrasound (EUS) as the main imaging modality in patients with moderate suspicion of common bile duct stones (CBDS).

METHODS: 55 patients with moderate clinical suspicion of CBDS were prospectively included to the study and evaluated with EUS. This study was done in single blind method in the clinical and biochemical data of patients. EUS was done with echo-endoscope Pentax FG 32-UA (f = 5-7.5 MHz) and Hitachi EUB 405 ultrasound machine. Patients diagnosed with CBDS by EUS were excluded from this study and treated with ERC. All the other patients were included to the follow up study obtained by mail every 6 months for clinical evaluation (need of ERC or surgery).

RESULTS: CBDS was found in 4 patients by EUS. Diagnosis was confirmed in all cases on ERC. The remaining 51 patients without CBDS on EUS were followed up for 6-26 months (meanly 13 months) There were: 40 women, 42 cholecystectomized patients, aged: 55 (mean). Biochemical values (mean values) were as follows: bilirubin: 14.9 μmol·L^-1, alkaline phosphatase: 95 IU·L^-1, γ-GTP: 131 IU·L^-1, ALT: 50 IU·L^-1, AST: 49 IU·L^-1. Only 1 patient was lost for follow up. In the remaining 50 patients with follow up, there was only 1 (2%) patient with persistent biliary symptoms in whom CBDS was finally diagnosed by ERC with ES. All other patients remained symptoms free on follow up and did not require ERC or biliary surgery.

CONCLUSION: Vast majority of patients with moderate suspicion of CBDS and no stones on EUS with linear array can avoid invasive evaluation of biliary tree with ERC.

The role of endoscopic ultrasound in hepatobiliary disease

The evaluation of hepatobiliary disease continues to change as new technologies are introduced. One of the more recent advances in hepatobiliary imaging has been the application of endoscopic ultrasound (EUS). Endoscopic retrograde cholangiopancreatography, computed tomography, conventional ultrasound, and magnetic resonance imaging were previously the primary means of evaluating hepatobiliary disease. The role of EUS as both a substitute and a complement for these historical imaging modalities continues to evolve. This review examines the current literature on EUS in the evaluation of hepatobiliary diseases, including choledocholithiasis, microlithiasis, biliary strictures, obstructive jaundice, cholangiocarcinoma, gallbladder polyps, and liver lesions.

Over-the-wire US catheter probe as an adjunct to ERCP in the detection of choledocholithiasis

BACKGROUND

Intraductal ultrasound (IDUS) as an adjunct to ERCP for detection of extrahepatic bile duct stones is technically easy, accurate, and safe. This prospective study evaluated IDUS with an "over-the-wire" catheter US probe as an adjunct to ERCP.

METHODS

Sixty-five patients, highly suspected to have choledocholithiasis, underwent IDUS during ERCP. The IDUS probe was inserted by means of the duodenoscope into the bile duct without performing a sphincterotomy. All stones identified by IDUS or retrograde cholangiography were removed with either a basket or retrieval balloon after endoscopic sphincterotomy.

RESULTS

The final diagnosis was choledocholithiasis in 59 patients. Bile duct diameter ranged from 0.6 to 2.3 cm and stone size from 2 mm to 2 cm. IDUS successfully identified all stones in these patients. IDUS resulted in 2 false-positive diagnoses in the remaining 6 patients without stones (overall accuracy 97%, sensitivity 100%, specificity 67%). Cholangiography detected stones in 55 of the patients with stones (accuracy 94%, sensitivity 93%, specificity 100%).

CONCLUSION

IDUS, a safe, technically easy procedure, is highly accurate in the detection of extrahepatic bile duct stones regardless of the diameter of the bile ducts. The "over-the-wire" technique preserves access to the cannulated duct. IDUS is an excellent adjunct to ERCP for the diagnosis of choledocholithiasis. IDUS differentiates stones from air bubbles and prevents unnecessary sphincterotomy.

Where do ERCP, endoscopic ultrasound, magnetic resonance cholangiopancreatography, and intraoperative cholangiography fit in the management of acute biliary pancreatitis? A decision analysis model

OBJECTIVES

The role of ERCP in acute biliary pancreatitis (ABP) is controversial. Magnetic resonance cholangiopancreatography (MRCP) and endoscopic ultrasonography (EUS) are modalities for bile duct visualization that could lower costs and prevent ERCP-related complications. We analyzed costs and examined the cost-effectiveness of these modalities to define their role in ABP.

METHODS

A decision analysis model of ABP was constructed. The strategies evaluated were 1) ERCP, 2) MRCP followed by ERCP if positive for common bile duct stones (CBDS) or if biliary sepsis ensued, 3) EUS followed by ERCP if positive or if biliary sepsis ensued, and 4) observation with intraoperative cholangiography at the time of cholecystectomy with ERCP only if biliary sepsis ensued. We compared costs and performed cost-effectiveness analysis between strategies at probabilities of CBDS ranging from 0% to 100%. The outcome measures were total costs and costs per ABP death prevented.

RESULTS

At probabilities of CBDS < 15%, observation with intraoperative cholangiography is the least expensive strategy, whereas EUS and ERCP are the least expensive strategies at probabilities of 15-58% and >58%, respectively. In terms of cost-effectiveness, at probabilities of CBDS of 7-45%, EUS is the most cost-effective alternative, and at a probability of >45% ERCP is the most cost-effective option.

CONCLUSIONS

Total costs and cost-effectiveness ratios of these strategies in patients with ABP are highly dependent on the probability of CBDS.

Comparison of intraductal ultrasonography with percutaneous transhepatic cholangioscopy for the identification of residual bile duct stones during lithotripsy

BACKGROUND

An imaging modality that can be used to identity small stones after a biliary lithotripsy is required. Intraductal ultrasonography was evaluated by using percutaneous transhepatic cholangioscopy as the gold standard.

METHODS

Lithotripsy, under percutaneous transhepatic cholangioscopy guidance, was performed in 20 patients. A thin-caliber ultrasonic probe (2.0 mm in diameter and 20 MHz frequency) was inserted into the bile duct through the percutaneous tract after lithotripsy, and residual stones were identified. This was followed by percutaneous transhepatic cholangioscopy.

RESULTS

In the extrahepatic bile ducts, intraductal ultrasonography provided images of all the stones demonstrated on cholangioscopy (n = 11). The sensitivity was superior to that of cholangiography (P < 0.005). However, in the intrahepatic bile ducts, intraductal ultrasonography only visualized the stones located in the cannulated lobe. Extrahepatic stones smaller than 5.0 mm in diameter or in a common hepatic duct larger than 15.0 mm in diameter were missed by cholangiography, but were visualized by the use of intraductal ultrasonography (P < 0.05).

CONCLUSIONS

Intraductal ultrasonography is equivalent to cholangioscopy in the extrahepatic bile ducts. Cholangiography and intraductal ultrasonography should be used in combination to image intrahepatic and extrahepatic stones.

Linear EUS for bile duct stones

BACKGROUND

Radial scanning endoscopic ultrasonography (EUS) has been shown, in experienced hands, to be a safe and accurate means of detecting bile duct stones. We compared linear array EUS with endoscopic retrograde cholangiopancreatography (ERCP), in our first 50 cases, to evaluate efficacy of this examination as well as the learning curve for this indication.

METHODS

A retrospective study was conducted on 50 patients with suspected choledocholithiasis. We compared results of EUS with those of ERCP as a reference. First a linear EUS examination was performed followed by ERCP, at a median interval of 31 days (range 3 to 162 days).

RESULTS

The average age of patients was 56 years (range 26 to 76); 48% were women. Fifteen (30%) had undergone cholecystectomy, a mean of 8.5 years (range 1 to 22) before the EUS. EUS compared with ERCP had a 97% sensitivity, 77% specificity, and 90% accuracy. In 14% of patients EUS provided an additional or alternative diagnosis: chronic pancreatitis (n = 3), duodenitis (2), bile duct stricture (1), chronic gastritis (1). No complications were encountered due to EUS.

CONCLUSIONS

We found in this early experience that linear array EUS is a reasonably safe and accurate means of detecting choledocholithiasis. Linear array EUS, despite the learning curve, seems to be about equivalent to radial EUS in accuracy. Appropriate use of this less invasive technique may possibly replace the use of diagnostic ERCP.

Prospective assessment of the utility of EUS in the evaluation of gallstone pancreatitis

BACKGROUND

The ability to identify common bile duct stones by noninvasive means in patients with acute biliary pancreatitis is limited. The aim of this study was to prospectively evaluate the ability of endosonography (EUS) to identify cholelithiasis and choledocholithiasis and predict disease severity in patients with nonalcoholic pancreatitis.

METHODS

EUS was performed immediately before endoscopic retrograde cholangiopancreatography (ERCP) by separate blinded examiners within 72 hours of admission. Gallbladder findings were compared between EUS and transabdominal ultrasonography (US). Using endoscopic extraction of a bile duct stone as the reference standard for choledocholithiasis, the diagnostic yield of EUS was compared with transabdominal US and ERCP. Features identified during endosonographic imaging of the pancreas were correlated with length of hospitalization.

RESULTS

Thirty-six patients were studied. EUS and transabdominal US were concordant in their interpretation of gallbladder findings in 92% of patients. The sensitivity of transabdominal US, EUS, and ERCP for identifying choledocholithiasis was 50%, 91%, and 92% and the accuracy was 83%, 97%, and 89%, respectively. Length of hospital stay was longer in patients with peripancreatic fluid (9.2 vs. 5.7 days, p < 0.1) and shorter in patients with coarse echo texture (2.6 vs. 7.2 days, p < 0.05) demonstrated on EUS.

CONCLUSIONS

EUS can reliably identify cholelithiasis and is more sensitive than transabdominal US in detecting choledocholithiasis in patients with biliary pancreatitis. EUS may be used early in the management of patients with acute pancreatitis to select those who would benefit from endoscopic stone extraction. The utility of EUS for predicting pancreatitis severity requires further investigation.

Bile duct stones and laparoscopic cholecystectomy: a decision analysis to assess the roles of intraoperative cholangiography, EUS, and ERCP

BACKGROUND

The least costly management strategy for patients undergoing laparoscopic cholecystectomy is unclear.

METHODS

A decision model incorporating cost ratios, test accuracy, complication, and failure rates was used to determine the costs of 4 peri-laparoscopic cholecystectomy strategies: endoscopic retrograde cholangiopancreatography (ERCP), intraoperative cholangiography (IOCG), endoscopic ultrasound (EUS), and expectant management.

RESULTS

Expert IOCG is least costly for intermediate-risk patients when the risk of stones is between 17% and 34%. If expert EUS is available, 0% to 10% ("low" risk) merits expectant management; 11% to 55% ("intermediate" risk) merits EUS; and greater than 55% ("high" risk) merits ERCP. Thresholds were most sensitive to changes in the risks of symptoms and complications due to retained stones; and to procedural costs, sensitivity, and success rates. Neither IOCG nor EUS appears likely to reduce overall costs unless their accuracy and success rates are greater than 90% and their procedural cost is less than 60% to 70% that of ERCP. When neither are available, ERCP is preferable when the risk of stones is greater than 22%. Thresholds were relatively insensitive to changes in the risk and severity of ERCP-induced pancreatitis.

CONCLUSIONS

The least costly strategy for laparoscopic cholecystectomy patients depends primarily on the risk of stones and stone-related symptoms, but procedural costs and operator expertise are also critical.

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).

Endoscopic ultrasonography versus cholangiography for the diagnosis of choledocholithiasis

BACKGROUND

Choledocholithiasis is a major source of morbidity among patients undergoing cholecystectomy for symptomatic gallstones. There is no consensus on the best approach to diagnosing bile duct stones. We compared the safety, accuracy, diagnostic yield, and cost of EUS- and ERCP-based approaches.

METHODS

Sixty-four consecutive pre- and post-cholecystectomy patients referred for endoscopic retrograde cholangiopancreatography (ERCP) for suspected choledocholithiasis were prospectively evaluated in a blinded fashion. All were stratified into risk groups using predefined criteria. Endoscopic ultrasonography (EUS) and ERCP were sequentially performed by two endoscopists.

RESULTS

The success rates of EUS and ERCP were 98% and 94%, respectively. The accuracy of EUS for diagnosing choledocholithiasis was 94%. EUS provided an additional or alternative diagnosis to bile duct stones in 21% of patients. The complication rate of EUS was significantly lower than diagnostic ERCP. An EUS-based strategy costs less than diagnostic ERCP in patients with low, moderate, or intermediate risk.

CONCLUSIONS

EUS is comparably accurate, but safer and less costly than ERCP for evaluating patients with suspected choledocholithiasis. It is useful in patients with an increased risk of having common bile duct stones based on clinical criteria and those with contraindications for or prior unsuccessful ERCP. EUS may enable selective performance of ERCP and improve the cost-effectiveness of diagnosing choledocholithiasis.

Endoscopic ultrasonography for diagnosing choledocholithiasis: a prospective comparative study with ultrasonography and computed tomography

BACKGROUND

We assessed the diagnostic usefulness of endoscopic ultrasonography (EUS) for choledocholithiasis.

METHODS

A prospective series of 155 patients with suspected choledocholithiasis all underwent EUS, conventional ultrasonography, CT, and ERCP. In 142 patients with a clear cholangiogram on ERCP, we analyzed the capability of EUS to image the extrahepatic bile duct and to identify choledocholithiasis, compared with ultrasonography and CT.

RESULTS

No complications were encountered in performing EUS. In 51 patients, ERCP demonstrated bile duct stones, which were confirmed at endoscopic sphincterotomy or surgery. The extrahepatic bile duct was wholly displayed in 96% by EUS, in 60% by ultrasonography, and in 80% by CT. EUS (96%) was more sensitive than ultrasonography (63%) and CT (71%) for detecting choledocholithiasis (p < 0.001). Although ultrasonography and CT were poorly diagnostic for choledocholithiasis in patients with small stones or those with a nondilated common bile duct, EUS was able to accurately detect choledocholithiasis regardless of the size of stones or the diameter of the bile duct. The specificity of EUS (100%) was higher than those of ultrasonography (95%) and CT (97%).

CONCLUSIONS

EUS, a safe imaging procedure, is more accurate than ultrasonography and CT and may be as accurate as ERCP for diagnosing choledocholithiasis.

Prospective controlled study of endoscopic ultrasonography and endoscopic retrograde cholangiography in patients with suspected common-bileduct lithiasis

BACKGROUND

Endoscopic sphincterotomy is sometimes done unnecessarily in patients with suspected choledocholithiasis. Our aims were to assess the diagnostic accuracy of endoscopic ultrasonography and endoscopic retrograde cholangiography (ERC) and to find out whether endoscopic ultrasonography may help to prevent unnecessary sphincterotomy or surgical explorations.

METHODS

We recruited 119 patients aged 70.4 (SD 16.1) years with strongly suspected choledocholithiasis who presented to our endoscopy unit between January, 1994, and January, 1995. During the same spell of sedation or within 2 h of each other, endoscopic ultrasonography and ERC were carried out by investigators unaware of the patient's history. Endoscopic sphincterotomy with instrumental exploration was then done as the gold standard for the presence or the absence of stones.

FINDINGS

78 (66%) patients had choledocholithiasis; 17 (14%) had other bileduct diseases; 24 (20%) had a clear bileduct or did not require an invasive endoscopic procedure. The sensitivity of endoscopic ultrasonography was 93%, specificity 97%, positive predictive value 98%, and negative predictive value 88%. The corresponding values for ERC were 89%, 100%, 100%, and 83%. There were five false-negative cases by endoscopic ultrasonography (of which three were also negative with ERC) and one false-positive. The morbidity rate was 4.1%.

INTERPRETATION

We conclude that endoscopic ultrasonography is at least as sensitive as ERC. Endoscopic ultrasonography may prevent inappropriate invasive explorations of the common bileduct.

Value of endoscopic ultrasonography in the diagnosis of common bile duct stones: comparison with surgical exploration and ERCP

An accurate and safe preoperative method of imaging the common bile duct is essential for the proper diagnosis of calculous biliary tract disease, especially in the current era of laparoscopic cholecystectomy. The value of endoscopic ultrasonography in detecting common duct stones has been reported, albeit in small series. The aim of this retrospective study was to assess the accuracy of EUS in a large series of patients. We compared EUS to direct cholangiography in the evaluation of 422 patients for common duct stones. Ductal stones were imaged by EUS in 168 patients (43.4%). No complications were encountered. EUS failed in 2.3% of cases, ERCP failed in 8.3%, and surgical exploration failed in 0.5%. Comparison of EUS with surgical exploration in 185 patients showed a sensitivity of 94.9%, a specificity of 97.8%, and an accuracy of 95.9%. EUS was compared to ERCP in 219 patients. All common duct stones found by ERCP were evident by EUS. Concordance was obtained in 91.3% of cases. Review of videotapes disclosed 3 false-positives and 16 unequivocal true-positives. We conclude that EUS is a safe and highly accurate means of detecting common duct stones and should be proposed before laparoscopic cholecystectomy in patients at risk of choledocholithiasis.

Endosonographic possibilities in the pancreatobiliary area

ES is certainly the most accurate technique presently available for visualizing small lesions in the pancreas and (distal) bile duct. However, this technique can at present not be utilized for improving the earlier diagnosis of pancreatic carcinoma but is of great help in the preoperative localization of pancreatic endocrine tumours. ES makes significant contributions to the preoperative loco-regional staging of pancreatic, ampullary and distal biliary malignancies, but it has distinct limitations in large masses and more remote areas (superior mesenteric vein) and in the differentiation between malignant and inflammatory lesions.