Role of Magnetic Resonance Cholangiography in the Diagnosis of Bile Duct Lithiasis

Updated guideline on the management of common bile duct stones (CBDS)

Common bile duct stones (CBDS) are estimated to be present in 10-20% of individuals with symptomatic gallstones. They can result in a number of health problems, including pain, jaundice, infection and acute pancreatitis. A variety of imaging modalities can be employed to identify the condition, while management of confirmed cases of CBDS may involve endoscopic retrograde cholangiopancreatography, surgery and radiological methods of stone extraction. Clinicians are therefore confronted with a number of potentially valid options to diagnose and treat individuals with suspected CBDS. The British Society of Gastroenterology first published a guideline on the management of CBDS in 2008. Since then a number of developments in management have occurred along with further systematic reviews of the available evidence. The following recommendations reflect these changes and provide updated guidance to healthcare professionals who are involved in the care of adult patients with suspected or proven CBDS. It is not a protocol and the recommendations contained within should not replace individual clinical judgement.

Laparoscopic common bile duct exploration versus ERCP/stenting and cholecystectomy: Is a single staged procedure better?

Aims: Choledocholithiasis is most common cause of obstructive jaundice. Laparoscopic choledocholithotomy has evolved as an alternative procedure to ERCP/ stenting in the management of choledocholithiasis. This study was aimed to compare the outcomes of laparoscopic CBD exploration with cholecystectomy (group 1) as compared to the conventional two staged procedure involving ERCP/ stenting (group 2). Methods: 60 patients admitted to our department (mean age = 45.52, SD = 17.71, 15 males, 45 females) for the management of choledocholithiasis from April 2014 to October 2015 were included in the study. We reviewed retrospectively the patients' data including age, sex, duration of the surgery, intra-operative and postoperative complications, duration of hospital stay, mortality and condition on follow-up. Results: Group 1 included 30 patients (mean age 50.76, 21 females, 9 males). The average operative time in this group was 110 minutes (96–145), stone clearance rate was 100%, and average hospital stay was 3.2 days (2–9). Group 2 also included 30 patients (mean age 44.36, 24 females, 6 males) with stone clearance rate of 70% (21 out of 30), average operative time 120.7 minutes (90–167), average hospital stay 9.1 (3–30) days and an average of 2.3 procedures per patient. Conclusion: In our study mean operative time, stone clearance rate, average hospital stay and average number of procedures per patient were found to be significantly lower in laparoscopic CBD exploration group. It can be concluded that laparoscopic CBD exploration with cholecystectomy is much safer and cost effective than the conventional two staged procedure involving ERCP/ stenting.

Cost-effectiveness analysis of endoscopic ultrasound versus magnetic resonance cholangiopancreatography in patients with suspected common bile duct stones

BACKGROUND

Patients with suspected common bile duct (CBD) stones are often diagnosed using endoscopic retrograde cholangiopancreatography (ERCP), an invasive procedure with risk of significant complications. Using endoscopic ultrasound (EUS) or Magnetic Resonance CholangioPancreatography (MRCP) first to detect CBD stones can reduce the risk of unnecessary procedures, cut complications and may save costs.

AIM

This study sought to compare the cost-effectiveness of initial EUS or MRCP in patients with suspected CBD stones.

METHODS

This study is a model based cost-utility analysis estimating mean costs and quality-adjusted life years (QALYs) per patient from the perspective of the UK National Health Service (NHS) over a 1 year time horizon. A decision tree model was constructed and populated with probabilities, outcomes and cost data from published sources, including one-way and probabilistic sensitivity analyses.

RESULTS

Using MRCP to select patients for ERCP was less costly than using EUS to select patients or proceeding directly to ERCP ($1299 versus $1753 and $1781, respectively), with similar QALYs accruing to each option (0.998, 0.998 and 0.997 for EUS, MRCP and direct ERCP, respectively). Initial MRCP was the most cost-effective option with the highest monetary net benefit, and this result was not sensitive to model parameters. MRCP had a 61% probability of being cost-effective at $29,000, the maximum willingness to pay for a QALY commonly used in the UK.

CONCLUSION

From the perspective of the UK NHS, MRCP was the most cost-effective test in the diagnosis of CBD stones.

Endoscopic ultrasound versus magnetic resonance cholangiopancreatography for common bile duct stones

BACKGROUND

Endoscopic ultrasound (EUS) and magnetic resonance cholangiopancreatography (MRCP) are tests used in the diagnosis of common bile duct stones in patients suspected of having common bile duct stones prior to undergoing invasive treatment. There has been no systematic review of the accuracy of EUS and MRCP in the diagnosis of common bile duct stones using appropriate reference standards.

OBJECTIVES

To determine and compare the accuracy of EUS and MRCP for the diagnosis of common bile duct stones.

SEARCH METHODS

We searched MEDLINE, EMBASE, Science Citation Index Expanded, BIOSIS, and Clinicaltrials.gov until September 2012. We searched the references of included studies to identify further studies and of systematic reviews identified from various databases (Database of Abstracts of Reviews of Effects (DARE), Health Technology Assessment (HTA), Medion, and ARIF (Aggressive Research Intelligence Facility)). We did not restrict studies based on language or publication status, or whether data were collected prospectively or retrospectively.

SELECTION CRITERIA

We included studies that provided the number of true positives, false positives, false negatives, and true negatives for EUS or MRCP. We only accepted studies that confirmed the presence of common bile duct stones by extraction of the stones (irrespective of whether this was done by surgical or endoscopic methods) for a positive test, and absence of common bile duct stones by surgical or endoscopic negative exploration of the common bile duct or symptom free follow-up for at least six months for a negative test, as the reference standard in people suspected of having common bile duct stones. We included participants with or without prior diagnosis of cholelithiasis; with or without symptoms and complications of common bile duct stones, with or without prior treatment for common bile duct stones; and before or after cholecystectomy. At least two authors independently screened abstracts and selected studies for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors independently collected the data from each study. We used the bivariate model to obtain pooled estimates of sensitivity and specificity.

MAIN RESULTS

We included a total of 18 studies involving 2366 participants (976 participants with common bile duct stones and 1390 participants without common bile duct stones). Eleven studies evaluated EUS alone, and five studies evaluated MRCP alone. Two studies evaluated both tests. Most studies included patients who were suspected of having common bile duct stones based on abnormal liver function tests; abnormal transabdominal ultrasound; symptoms such as obstructive jaundice, cholangitis, or pancreatitis; or a combination of the above. The proportion of participants who had undergone cholecystectomy varied across studies. Not one of the studies was of high methodological quality. For EUS, the sensitivities ranged between 0.75 and 1.00 and the specificities ranged between 0.85 and 1.00. The summary sensitivity (95% confidence interval (CI)) and specificity (95% CI) of the 13 studies that evaluated EUS (1537 participants; 686 cases and 851 participants without common bile duct stones) were 0.95 (95% CI 0.91 to 0.97) and 0.97 (95% CI 0.94 to 0.99). For MRCP, the sensitivities ranged between 0.77 and 1.00 and the specificities ranged between 0.73 and 0.99. The summary sensitivity and specificity of the seven studies that evaluated MRCP (996 participants; 361 cases and 635 participants without common bile duct stones) were 0.93 (95% CI 0.87 to 0.96) and 0.96 (95% CI 0.90 to 0.98). There was no evidence of a difference in sensitivity or specificity between EUS and MRCP (P value = 0.5). From the included studies, at the median pre-test probability of common bile duct stones of 41% the post-test probabilities (with 95% CI) associated with positive and negative EUS test results were 0.96 (95% CI 0.92 to 0.98) and 0.03 (95% CI 0.02 to 0.06). At the same pre-test probability, the post-test probabilities associated with positive and negative MRCP test results were 0.94 (95% CI 0.87 to 0.97) and 0.05 (95% CI 0.03 to 0.09).

AUTHORS' CONCLUSIONS

Both EUS and MRCP have high diagnostic accuracy for detection of common bile duct stones. People with positive EUS or MRCP should undergo endoscopic or surgical extraction of common bile duct stones and those with negative EUS or MRCP do not need further invasive tests. However, if the symptoms persist, further investigations will be indicated. The two tests are similar in terms of diagnostic accuracy and the choice of which test to use will be informed by availability and contra-indications to each test. However, it should be noted that the results are based on studies of poor methodological quality and so the results should be interpreted with caution. Further studies that are of high methodological quality are necessary to determine the diagnostic accuracy of EUS and MRCP for the diagnosis of common bile duct stones.

Magnetic resonance cholangiopancreatography: utilization and usefulness in suspected choledocholithiasis

BACKGROUND

The aim of this study was to evaluate the role of magnetic resonance cholangiopancreatography in cases of suspected choledocholithiasis.

METHODS

Suitable candidates were recruited from a database of all consecutive patients who underwent magnetic resonance cholangiopancreatography between March 2009 and December 2012. Patients were stratified into low, medium and high risk for choledocholithiasis by assessing clinical symptoms, liver function tests and ultrasonography. True negatives and false positives were calculated based on endoscopic retrograde cholangiopancreatography, intraoperative cholangiogram and clinical follow-up.

RESULTS

Of 201 magnetic resonance cholangiopancreatography investigations conducted, choledocholithiasis was diagnosed in 37 (18%) patients. In total, there was one false negative and three false positives. Total sensitivity and specificity values were 97% and 98%, respectively. These values were highest among low-risk patients (100% for both sensitivity and specificity). By initially opting for magnetic resonance imaging in suitable moderate- and high-risk patients, unnecessary endoscopic retrograde cholangiopancreatography procedures were avoided in 61% and 65% of patients, respectively.

CONCLUSION

Magnetic resonance cholangiopancreatography for patients with suspected choledocholithiasis yields high sensitivity and specificity. Given its reduced risk profile and relative ease of administration, magnetic resonance cholangiopancreatography is a necessary tool for the assessment of choledocholithiasis with the capacity to rival gold standard diagnostic techniques and help reduce the number of unnecessary interventional procedures.

[Design of a preoperative predictive score for choledocholithiasis]

INTRODUCTION

Choledocholithiasis is the most common cause of obstructive jaundice and occurs in 5-10% of patients with cholelithiasis.

OBJECTIVES

To design a preoperative predictive score for choledocholithiasis.

MATERIAL AND METHODS

A prospective study was carried out in 556 patients admitted to our department for biliary disease. Preoperative clinical, laboratory, and ultrasound variables were compared between patients without choledocholithiasis and 65 patients with this diagnosis. A multivariate logistic analysis was performed to obtain a predictive model of choledocholithiasis, determining sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).

RESULTS

Predictors of choledocholithiasis were the presence of a prior history of biliary disease (history of biliary colic, acute cholecystitis, choledocholithiasis or acute biliary pancreatitis) (p=0.021, OR=2.225, 95% CI: 1.130-4.381), total bilirubin values >4mg/dl (p=0.046, OR=2.403, 95% CI: 1.106-5.685), alkaline phosphatase values >150mg/dl (p=0.022 income, OR=2.631, 95%: 1.386-6.231), gamma-glutamyltransferase (GGT) values >100mg/dl (p=0.035, OR=2.10, 95% CI: 1.345-5.850), and an ultrasound finding of biliary duct >8mm (p=0.034, OR=3.063 95% CI: 1086-8649). A score superior to 5 had a specificity and PPV of 100% for detecting choledocholithiasis and a score less than 3 had a sensitivity and NPV of 100% for excluding this diagnosis.

CONCLUSIONS

The preoperative score can exclude or confirm the presence of choledocholithiasis and allows patients to directly benefit from laparoscopic cholecystectomy (LC) or prior endoscopic retrograde cholangiopancreatography (ERCP).

A prospective randomized trial comparing two-stage versus single-stage management of patients with gallstone disease and common bile duct stones

BACKGROUND

The optimal management of patients with concomitant common bile duct stones and gallstones is still evolving. With the introduction of laparoscopic common bile duct exploration, many centers prefer single-stage laparoscopic cholecystectomy and common bile duct exploration over preoperative endoscopic bile duct clearance followed by laparoscopic cholecystectomy. The present study was done to compare these two management options.

PATIENTS AND METHODS

30 patients with symptomatic gallstones and common bile duct stones were randomized to either treatment option. Preoperative endoscopic ultrasound (EUS) and/or magnetic resonance pancreaticography (MRCP) was done in all patients to confirm the diagnosis. In group I, laparoscopic cholecystectomy and common bile duct exploration was done at the same sitting; in group II, endoscopic stone clearance was followed by laparoscopic cholecystectomy 4-6 weeks later. Success was defined as successful treatment by the intended modality.

RESULTS

15 patients were randomized to each group and the two groups had comparable demographic and clinical profile. In group I there was a success rate of 93.5% in comparison with 86.7% in group II (p = 0.32, Fisher's exact test). The complications were similar in the two groups.

CONCLUSIONS

The results showed equivalent success rate in terms of morbidity and hospital stay. Laparoscopic approach seems to be favorable because of the smaller number of procedures and hospital visits.

The role of nonenhanced magnetic resonance imaging in the early assessment of acute pancreatitis

BACKGROUND AND AIMS

Computed tomography (CT), especially contrast-enhanced CT (CECT), provides important information on the severity and prognosis of acute pancreatitis (AP). Magnetic resonance imaging (MRI) has become a useful tool as an alternative to CT in the assessment of AP. The primary aim of our study was to determine the diagnostic value of nonenhanced MRI (NEMRI) to assess severity and predict outcome in patients with AP from the third to fifth day after admission. We also correlated MRI findings with CT and biochemical parameters.

PATIENTS AND METHODS

The study included 101 patients (49 men, 52 women, median age 62 yr, range 20-82) with a diagnosis of AP admitted to our hospital between January 1, 2004 and June 31, 2005. The inclusion criteria consisted of a combination of clinical features, a typical case history, elevation of serum pancreatic enzymes, and diagnosis confirmed by imaging studies. Contrast-enhanced spiral CT exams were performed in all patients from the third to fifth day after admission, and Balthazar grade and CT severity index were calculated. All patients underwent NEMRI, and MR severity index (MRSI) was calculated. We also performed magnetic resonance cholangiopancreatography (MRCP) in all patients to detect bile duct lithiasis.

RESULTS

Significant correlation between CECT and NEMRI was found for Balthazar grade (P<0.001) and the assessment of pancreatic necrosis (P<0.001), as well as between the combined severity indices (rho=0.819, P<0.001). MRSI correlated with Ranson score (rho=0.656, P<0.01), C-reactive protein (CRP) levels 48 h after admission (rho=0.502, P<0.01), appearance of systemic complications (rho=0.576, P<0.01), and length of hospital stay (rho=0.484, P<0.01). Considering the Atlanta criteria as the gold standard and the Ranson score, no difference in sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the two methods was observed. Comparing the group of patients with presumed acute pancreatic hemorrhage with the group of patients with severe AP, we found a significantly higher APACHE II score on the first day (P<0.05), that the development of systemic complications was more frequent (P < 0.05), and that the hospital stay and ICU management of patients with MRI signs of pancreatic hemorrhage tended to be longer.

CONCLUSION

NEMRI is comparable to CECT in the early assessment of the severity of AP, and both methods are equally efficient in predicting local and systemic complications of AP. MRI has a potential advantage over CT in detecting bile duct lithiasis and pancreatic hemorrhage.