Cost-effectiveness of endoscopic ultrasonography, magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography in patients suspected of pancreaticobiliary disease

Assessing the impact of center volume on the cost-effectiveness of centralizing ERCP

BACKGROUND AND AIMS

ERCP is a complex endoscopic procedure in which the center's procedure volume influences outcomes. With the increasing healthcare expenses and limited resources, promoting cost-effective care becomes essential for healthcare provision. This study was a cost-effectiveness analysis to evaluate the hypothesis that high-volume (HV) centers perform ERCP with higher quality at lower costs than low-volume (LV) centers.

METHODS

A baseline case compared the current distribution of ERCPs among HV and LV centers with a hypothetical scenario in which all ERCPs are performed at HV centers. A cost-effectiveness analysis was constructed, followed by 1- and 2-way sensitivity analyses, and probabilistic sensitivity analysis using Monte Carlo simulations.

RESULTS

In the baseline case, the incremental cost-effectiveness ratio was -$151,270 per year, due to the hypothetical scenario's lower costs and slightly higher quality-adjusted life years. The model was most sensitive to changes in transportation costs (109.34%), probability of significant adverse events (AEs) after successful ERCP at LV centers (42.12%), utility after ERCP with significant AEs (30.10%), and probability of significant AEs after successful ERCP at HV centers (23.53%); only transportation costs above $3655 changed the study outcome, however. The current ERCP distribution would only be cost-effective if LV centers achieved higher success (≥92.4% vs 89.3%), with much lower significant AEs (≤.5% vs 6.7%). The study's main findings remained unchanged while combining all model parameters in the probabilistic sensitivity analysis.

CONCLUSIONS

Our findings show that HV centers have high-performance rates at lower costs, raising the need to consider the principle of centralization of ERCPs into HV centers to improve the quality of care.

Management of Suspected Choledocholithiasis: A Decision Analysis for Choosing the Optimal Imaging Modality

BACKGROUND AND AIMS

Magnetic resonance cholangiography (MRC), endoscopic ultrasound (EUS), and endoscopic retrograde cholangio-pancreatography (ERCP) all represent viable options to establish the diagnosis of choledocholithiasis. The aim of the study was to assess how the three imaging modalities perform in head-to-head comparisons and in what order to apply them when using these procedures sequentially.

METHODS

A threshold analysis using a decision tree was modeled to compare the costs associated with different imaging techniques of the biliary system in a patient with suspected cholestasis secondary to choledocholithiasis. The main outcome parameter was the pre-test probability of common bile duct (CBD) stones that would guide the physician towards starting the work-up with MRC or EUS versus going straight to ERCP as the primary procedure.

RESULTS

For low pre-test probabilities of CBD stones in the common bile duct, MRC represents the procedure of choice. For pre-test probabilities ranging between 40 and 91 %, EUS should be the preferred imaging modality. If CBD stones are suspected with an even higher pre-test probability, patients could go straight to ERCP as their first procedure. Low costs associated with any of the three procedures increase its range of applicability at the expense of the other competing imaging modalities.

CONCLUSIONS

MRC, EUS, and ERCP should be used in sequence and dependent on the pre-test probability of choledocholithiasis.

Is preoperative MRCP necessary for patients with gallstones? An analysis of the factors related to missed diagnosis of choledocholithiasis by preoperative ultrasound

Background

The diagnosis of associated choledocholithiasis prior to cholecystectomy for patients with gallstones is important for the surgical decision and treatment efficacy. However, whether ultrasound is sufficient for preoperative diagnosis of choledocholithiasis remains controversial, with different opinions on whether routine magnetic resonance cholangiopancreatography (MRCP) is needed to detect the possible presence of common bile duct (CBD) stones.

Methods

In this study, a total of 413 patients with gallstones who were admitted to the Department of General Surgery of the First Affiliated Hospital of Harbin Medical University in China for a period of 3 years and underwent both ultrasound and MRCP examinations were retrospectively analysed. After reviewing and screening these cases according to the literature, 11 indicators including gender, age, alanine aminotransferase, aspartate aminotransferase, total bilirubin, direct bilirubin, indirect bilirubin, alkaline phosphatase, γ-aminotransferase, CBD diameter, and concurrent acute cholecystitis were selected and comparatively analysed.

Results

Among the 413 patients, a total of 109 cases showed concurrent gallstones and choledocholithiasis, accounting for 26.39 % of all cases. Among them, 60 cases of choledocholithiasis were revealed by ultrasound examination, accounting for 55.05 %, while 49 cases of choledocholithiasis were not detected by ultrasound examination but were confirmed by MRCP instead (the missed diagnosis rate of ultrasound was 44.95 %). The results of statistical analysis suggested that alanine aminotransferase, acute cholecystitis, and CBD diameter were the three most relevant factors for missed diagnosis by ultrasound.

Conclusion

The accuracy of preoperative ultrasonography for the diagnosis of associated CBD stones for patients with gallstones is not high. However, elevated alanine aminotransferase, concurrent acute cholecystitis, and CBD diameter were identified as key factors that may affect the accuracy of the diagnosis. Thus, routine preoperative MRCP examination is suggested for patients with gallstones to rule out possible concomitant CBD stones.

MRCP is not a cost-effective strategy in the management of silent common bile duct stones

BACKGROUND

Few formal cost-effectiveness analyses simultaneously evaluate radiographic, endoscopic, and surgical approaches to the management of choledocholithiasis.

STUDY DESIGN

Using the decision analytic software TreeAge, we modeled the initial clinical management of a patient presenting with symptomatic cholelithiasis without overt signs of choledocholithiasis. In this base case, we assumed a 10 % probability of concurrent asymptomatic choledocholithiasis. Our model evaluated four diagnostic/therapeutic strategies: universal magnetic resonance cholangiopancreatography (MRCP), universal endoscopic retrograde cholangiopancreatography (ERCP), laparoscopic cholecystectomy (LC), or laparoscopic cholecystectomy with universal intraoperative cholangiogram (LCIOC). All probabilities were estimated from a review of published literature. Procedure and intervention costs were equated with Medicare reimbursements. Costs of hospitalizations were derived from median hospitalization reimbursement for New York State using diagnosis-related groups (DRG). Sensitivity analyses were performed on all cost and probability variables.

RESULTS

The most cost-effective strategy in the diagnosis and management of symptomatic cholelithiasis with a 10 % risk of asymptomatic choledocholithiasis was LCIOC. This was followed by LC alone, MRCP, and ERCP. LC was preferred only when the probability that a retained CBD stone would eventually become symptomatic fell below 15 % or if the probability of technical success of an intraoperative cholangiogram (IOC) was less than 35 %. Universal MRCP and ERCP were both more costly and less effective than surgical strategies, even at a high probability of asymptomatic choledocholithiasis. Within the tested range for both procedural and hospitalization-related costs for any of the surgical or endoscopic interventions, LCIOC and LC were always more cost-effective than universal MRCP or ERCP, irrespective of the presence or absence of complications. Varying the cost, sensitivity, and specificity of MRCP had no effect on this outcome.

CONCLUSIONS

LC with routine IOC is the preferred strategy in a cost-effectiveness analysis of the management of symptomatic cholelithiasis with asymptomatic choledocholithiasis. MRCP was both more costly and less effective under all tested scenarios.

Impact of magnetic resonance cholangiography in managing liver-transplanted patients: preliminary results of a clinical decision-making study

PURPOSE

This study was performed to assess the role of magnetic resonance cholangiography (MRC) in the clinical decision-making process of referring physicians when managing liver-transplanted patients.

MATERIALS AND METHODS

Over a 6-month period, 21 liver-transplanted patients with a suspected biliary complication were referred for MRC. Referring physicians were asked to prospectively state, before and after MRC, the leading diagnosis; the level of confidence (on a 0-100% scale); the most appropriate diagnostic/therapeutic plan. Data analysis assessed was the diagnostic yield of MRC; the proportion of change in the leading diagnosis; the therapeutic efficacy (i.e. proportion of change in the initial diagnostic/therapeutic plan); the diagnostic thinking efficacy (i.e., gain in diagnostic confidence). Statistical significance was assessed with the Mann-Whitney U test. MRC accuracy was also calculated.

RESULTS

Data analysis showed a diagnostic yield of 85.7%; a proportion of change in leading diagnosis of 19.0%; a therapeutic efficacy of 42.8%; a diagnostic thinking efficacy for concordant and discordant leading diagnoses of 18.8% and 78.7%, respectively (p<0.01). MRC accuracy was 92.3%.

CONCLUSIONS

MRC significantly increased the diagnostic confidence, irrespective of the concordance between pre- and posttest diagnoses. Moreover, MRC determined a change in patient management in a significant proportion of cases, leading to clinical benefits.

Diagnostic yield of ERCP and secretin-enhanced MRCP and EUS in patients with acute recurrent pancreatitis of unknown aetiology

BACKGROUND

Magnetic resonance cholangio-pancreatography (MRCP), endoscopic ultrasonography (EUS), and endoscopic cholangio-pancreatography (ERCP) are the most frequently employed second-step procedures to detect biliary and pancreatic abnormalities in patients with acute recurrent pancreatitis (ARP) of unknown aetiology. MRCP and EUS both give a better view of the bilio-pancreatic ductal system after secretin stimulation (MRCP-S, EUS-S). EUS also serves to identify changes in the pancreatic parenchyma consistent with chronic pancreatitis, at an early stage. However, no studies have compared MRCP-S, EUS-S, and ERCP in the diagnosis of recurrent pancreatitis.

AIM

To prospectively compare the diagnostic yield of MRCP-S, EUS-S, and ERCP in the evaluation of patients with acute recurrent pancreatitis with non-dilated ducts, of unknown aetiology.

METHODS

Forty-four consecutive patients with ARP were prospectively scheduled to undergo MRCP-S, EUS-S and ERCP, in accordance with a standard protocol approved by the institutional review board. Diagnoses such as biliary microlithiasis, congenital variants of the pancreatic ducts, chronic pancreatitis and sphincter of Oddi dysfunction were compared between the three procedures. The diagnosis of chronic pancreatitis was established according to ductal morphology by MRCP-S and ERCP, ductal and parenchymal morphology by EUS-S.

RESULTS

The three procedures combined achieved a diagnosis that could have explained the recurrence of pancreatitis in 28/44 patients (63.6%). EUS-S recognized ductal and/or parenchymal abnormalities with the highest frequency (35/44 patients, 79.5%). Both MRCP-S and EUS-S were superior to ERCP for detecting pancreatic ductal abnormalities. EUS-S showed up pancreatic parenchymal changes in more than half the cases. Both EUS and MRCP secretin kinetics were concordant in identifying two cases with sphincter of Oddi dysfunction.

CONCLUSIONS

The diagnostic yield of EUS-S in recurrent pancreatitis with non-dilated ducts and unknown aetiology was 13.6% and 16.7% higher than MRCP-S and ERCP respectively (although not significant), which both gave substantially similar diagnostic yields. In no case did ERCP alone find a diagnosis missed by the other two procedures. MRCP-S and EUS-S should both be used in the diagnostic work-up of idiopathic recurrent pancreatitis as complementary, first-line, techniques, instead of ERCP.

Endosonography- vs. endoscopic retrograde cholangiopancreatography-based strategies in the evaluation of suspected common bile duct stones in patients with normal transabdominal imaging

BACKGROUND

Endosonography (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) are highly accurate techniques for evaluating common bile duct stones.

AIM

To compare the clinical impact and costs of EUS- and ERCP-based strategies for evaluating patients with suspected common bile duct stones but normal transabdominal imaging.

METHODS

The costs of EUS- vs. ERCP-based strategies were compared in patients with suspected acute biliary obstruction from common bile duct stones but normal transabdominal imaging.

RESULTS

Over a 15-month period, 110 patients were recruited. EUS detected a common bile duct lesion in 73% (common bile duct stones: 68%; pancreatic cancer: 2%; ampulla tumour: 2%; cholangiocarcinoma: 1%). The sensitivity, specificity, positive predictive value and negative predictive value of EUS were 98%, 100%, 100% and 93%, respectively. EUS prevented 30% unnecessary ERCP. The mean difference in cost per patient between EUS- and ERCP-based strategies was US$166. When stratified according to clinical indications, an EUS-based strategy was costlier only in suspected biliary sepsis. Costs were similar when the indications were cholestatic jaundice, acute pancreatitis and cholestasis.

CONCLUSION

EUS prior to biliary interventions in patients with suspected common bile duct stones prevented unnecessary ERCP. It allowed a definitive diagnosis to be made prior to more invasive procedures.

Endoscopic ultrasound: a meta-analysis of test performance in suspected biliary obstruction

BACKGROUND & AIMS

Endoscopic ultrasound (EUS) achieves high-resolution images of the bile duct and pancreas, while avoiding the risks of ERCP (endoscopic retrograde cholangiopancreatography). It appears comparable to MRCP (magnetic resonance cholangiopancreatography), although its use is less widely disseminated. We aimed to summarize EUS test performance in suspected biliary disease with meta-analysis.

METHODS

MEDLINE search (January 1987-September 2006), selected reference lists, external experts, and manual search of abstracts were used. Studies permitting (re)construction of 2 x 2 tables for EUS versus a gold standard were used. Random-effects models were used to estimate pooled sensitivity and specificity after adjusting for a number of potential confounders. Summary receiver operating characteristic analysis, with the sensitivity corresponding to the point on the receiver operating characteristic curve where sensitivity equals specificity (Q*) and area under the curve, was performed. The effects of sample size, quality, disease prevalence and spectrum, pancreatitis, echoendoscope type, and EUS era on diagnostic performance were assessed. Performance regarding presence of obstruction, choledocholithiasis, and malignancy was analyzed.

RESULTS

Thirty-six eligible, non-overlapping studies met inclusion criteria (3532 subjects). EUS had a high overall pooled sensitivity (88%; 95% confidence interval, 85%-91%) and specificity (90%; 87%-93%) for biliary obstruction (area under the curve = 0.97; Q* = 0.92). EUS had higher sensitivity (89%; 87%-91%) and specificity (94%; 91%-96%) for choledocholithiasis than for malignancy (sensitivity, 78%; 69%-85%; specificity, 84%; 78%-91%). Smaller studies and ones mainly studying patients with suspected strictures were associated with lower test performance.

CONCLUSIONS

There is excellent overall accuracy for EUS in diagnosing choledocholithiasis, with less impressive results for malignancy (when fine-needle aspiration is not used).