[Diagnostic performance of biliopancreatic endosonography in patients with intermediate risk of choledocholithiasis]. / Rendimiento diagnóstico de la endosonografía biliopancreática en pacientes con riesgo intermedio de coledocolitiasis.

OBJECTIVE: Determine the sensitivity and specificity of the ESBP for diagnosis in patients with intermediate risk of choledocholithiasis, referred to the specialized surgical Gastroenterology center of Unión de Cirujanos SAS - Oncologists of the West Zentria group - Manizales - Colombia between March 01, 2020 to January 31, 2022. MATERIALS AND METHODS: Retrospective cross-sectional study in patients with intermediate risk for choledocholithiasis. The diagnostic performance of ESBP was calculated and confirmed with ERCP. Negative ESBPs were followed up by telephone. RESULTS: 752 cases with ESBP were analyzed, of which 43.2% (n=325) were positive and 56.8% (n=427) were negative. ERCP was performed in positive cases who accepted the procedure (n=317); 73.5% (n:233) were positive for choledocholithiasis, 25.8% (n=82) tumors and 0.6% (n=2) biliary roundworms. Patients with positive ESBP underwent ERCP. S= 98.3% (95% CI: 95.7-99.5) was obtained; E= 88.1% (95% CI: 79.2-94.1); PPV = 95.8% (95% CI: 92.4-98.0); NPV = 94.9% (95% CI: 87.4-98.7). The AUC of ESBP was 0.9319 (95% CI 0.8961-0.967). CONCLUSION: In patients with intermediate risk for choledocholithiasis, ESBP is a useful diagnostic option in the study of pancreatic pathologies, extrahepatic biliary tree, and the identification of biliary microlithiasis; Therefore, it also allows us to complement it with a therapeutic intervention such as ERCP in a single time.

How I Do It: Robotic Choledochoscopy.

BACKGROUND: As the use of the robotic platform increases among general surgeons, the amount of robotic cholecystectomies is expected to increase as well. The use of intraoperative cholangiography is valuable in assessing for choledocholithiasis. We describe our technique of performing robotic intraoperative cholangiograms with choledochoscopy. Out technique aids in efficiency since no undocking is required. METHODS: Preoperatively, the decision to perform a cholangiogram is made based on physical exam, labs, and imaging findings. The procedure begins with obtaining a critical view of safety. The robotic arms are positioned in a manner that allows all 4 robotic arms to remain docked. A ductotomy is made and the cholangiocatheter is introduced. The cholangiogram images are then interpreted and if a stone is seen in the common bile duct we will then perform a transcystic common bile duct exploration using the SpyGlass Discover digital. A complete cholangiogram is then performed. The cystic duct is secured and the gallbladder is removed from the liver bed. The patients are watched overnight and discharged on postoperative day 1. CONCLUSIONS: A robotic approach to performing a transcystic common bile duct exploration is a safe and reproducible treatment method for choledocholithiasis. Our approach offers an advantage since no undocking is required.

Obesity and Risk for Incomplete Stone Clearance in Patients with Bile Duct Stones Undergoing ERCP.

INTRODUCTION: Obesity degrades fluoroscopic image quality and could impact on the endoscopic retrograde cholangiopancreatography (ERCP) outcomes. Our study aimed to compare the clinical outcomes and adverse events (AEs) between obese and non-obese patients undergoing ERCP for biliary stone-related conditions. METHODS: Patients who underwent ERCP for biliary-stone related conditions were included. The analyzed outcomes included the rates of successful bile duct cannulation, incomplete bile duct stone clearance, recurrent bile duct stones, and AEs. RESULTS: A total of 229 patients (116 obese patients and 113 non-obese patients) were included. All patients had successful bile duct cannulation. The rates of incomplete bile duct stone clearance (11.3% vs. 9.0%, P = 0.51), recurrent bile duct stones (1.9% vs. 4.2%, P = 0.24), and AEs (1.8% vs. 0.7%, P = 0.43) were not significantly different between the two groups, respectively. CONCLUSION: Our study demonstrates no associations between obesity and the rates of incomplete stone clearance, recurrent stones, successful cannulation, or AEs in patients undergoing ERCP for biliary stone-related disease.

A machine learning-based choledocholithiasis prediction tool to improve ERCP decision making: a proof-of-concept study.

BACKGROUND: Previous studies demonstrated limited accuracy of existing guidelines for predicting choledocholithiasis, leading to overutilization of endoscopic retrograde cholangiopancreatography (ERCP). More accurate stratification may improve patient selection for ERCP and allow use of lower-risk modalities. METHODS: A machine learning model was developed using patient information from two published cohort studies that evaluated performance of guidelines in predicting choledocholithiasis. Prediction models were developed using the gradient boosting model (GBM) machine learning method. GBM performance was evaluated using 10-fold cross-validation and area under the receiver operating characteristic curve (AUC). Important predictors of choledocholithiasis were identified based on relative importance in the GBM. RESULTS: 1378 patients (mean age 43.3 years; 61.2% female) were included in the GBM and 59.4% had choledocholithiasis. Eight variables were identified as predictors of choledocholithiasis. The GBM had accuracy of 71.5% (SD 2.5%) (AUC 0.79 [SD 0.06]) and performed better than the 2019 American Society for Gastrointestinal Endoscopy (ASGE) guidelines (accuracy 62.4% [SD 2.6%]; AUC 0.63 [SD 0.03]) and European Society of Gastrointestinal Endoscopy (ESGE) guidelines (accuracy 62.8% [SD 2.6%]; AUC 0.67 [SD 0.02]). The GBM correctly categorized 22% of patients directed to unnecessary ERCP by ASGE guidelines, and appropriately recommended as the next management step 48% of ERCPs incorrectly rejected by ESGE guidelines. CONCLUSIONS: A machine learning-based tool was created, providing real-time, personalized, objective probability of choledocholithiasis and ERCP recommendations. This more accurately directed ERCP use than existing ASGE and ESGE guidelines, and has the potential to reduce morbidity associated with ERCP or missed choledocholithiasis.

Endoscopic ultrasound avoids diagnostic ERCP among the ASGE high-risk group - Experience in an Asian population.

BACKGROUND: A prediction system for common bile duct (CBD) stones was originally published by the American Society for Gastrointestinal Endoscopy (ASGE) in 2010 and was last revised in 2019. We wanted to investigate its application in an Asian population, who have different etiologies of bile duct stone formation and accessibility to medical service compared to the West. METHODS: This is a single center retrospective study. Patients who received endoscopic ultrasound (EUS) for suspected CBD stones were collected from our endoscopic record system over a 10-year period. The accuracy of the revised ASGE criteria was estimated according to the results of EUS. A minimum follow-up of 6 months was required to detect false negative results. RESULTS: 142 patients were enrolled, 87 (61%) patients had CBD stones. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of the revised ASGE criteria for high-risk patients were 69%, 38%, 64%, 44%, and 57%. 36% of the ASGE-defined high-risk patients negative for CBD stones on EUS. The two significant predictors for CBD stone were CBD dilatation (adjusted OR 3.06, 95% C.I. 1.31-7.17, p = 0.010) and ascending cholangitis (adjusted OR 2.28, 95% C.I. 1.01-5.15, p = 0.047). CONCLUSION: ASGE recommends that patients defined as high-risk for choledocholithiasis be considered for direct ERCP without prior need for confirmation imaging. However, our findings indicate a high rate (36%) of patients in that group negative for CBD stones on EUS. Hence, EUS is still be suggested first in selective high-risk patients so that diagnostic ERCP can be avoided in our Asian society.

Ultrasound-Guided Percutaneous Transhepatic Cholangioscopic Lithotripsy for the Treatment of Common Bile Duct Stones and Analysis of Risk Factors for Recurrence.

BACKGROUND: As a minimally invasive treatment for common bile duct (CBD) stones, ultrasound-guided percutaneous transhepatic cholangioscopic lithotripsy (PTCSL) is gaining attention and recognition from the medical community. METHODS: A retrospective analysis was conducted on patients with CBD stones treated in our hospital from January 2016 to April 2022. Patients were divided into three groups: 77 treated with PTCSL, 93 with endoscopic retrograde cholangiopancreatography (ERCP), and 103 with laparoscopic common bile duct exploration (LCBDE). Their clinical data, perioperative indicators, and complications were analyzed comparatively. Then, risk factors for the post-PTCSL recurrence of CBD stones were analyzed by logistic regressions. Finally, the receiver operating characteristic curve was drawn. RESULTS: All perioperative indicators of the PTCSL group were better than the LCBDE group (P < 0.001). The incidences of cholangitis, hemobilia, and incisional infection after surgery were lower in the PTCSL group than in the LCBDE group (P < 0.05). Pancreatitis, reflux esophagitis, and papillary stenosis occurred less frequently in the PTCSL group than in the ERCP group (P < 0.05). Logistic regression analysis indicated that gallstones and family history were independent risk factors. The AUC for recurrent CBD stones predicted by multi-indicators was 0.895 (95% CI 0.792-0.999, P < 0.001) with a sensitivity of 96.7% and specificity of 68.8%. CONCLUSIONS: Ultrasound-guided PTCSL is a safe and effective treatment for CBD stones. Patients recovered quickly with fewer postoperative complications. It can be a first-line treatment for CBD stones. Gallstones and family history are independent risk factors for recurrent CBD stones, which provide a reference for clinicians in identifying the high-risk population needing close follow-up.

Haemorrhagic cholecystitis in a young patient, complicated by gallbladder perforation and choledocholithiasis.

Haemorrhagic cholecystitis is a rare condition associated with a high risk of morbidity and mortality. Its pathophysiology is thought to be due to gallbladder wall erosion and infarction secondary to inflammation, which subsequently leads to haemorrhage into the gallbladder lumen or the peritoneal cavity. There is no current official guidance on optimal management of this condition. We describe a case of a female patient in her 40s who presented with right upper quadrant pain, followed by haematemesis. After CT scan, a diagnosis of haemorrhagic cholecystitis was made and initially managed conservatively. In this case, haemorrhagic cholecystitis was later complicated by gallbladder perforation and choledocholithiasis. Definitive management was with emergency open cholecystectomy. We believe this to be the first reported case of haemorrhagic cholecystitis complicated by gallbladder perforation and choledocholithiasis. This report highlights the need for early definitive management of haemorrhagic cholecystitis to prevent subsequent complications.

Contemporary management of common bile duct stone: What you need to know.

ABSTRACT: Choledocholithiasis is a common presentation of symptomatic cholelithiasis encountered by the acute care surgeon. There is a wide spectrum of variation in management of this disease due to evolutions in laparoscopic and endoscopic techniques. Intricacies in management are related to the timing of diagnosis as well as locally available imaging modalities, surgical expertise, and ancillary advanced endoscopy and interventional radiological support. While individual patient demographics and institutional characteristics will determine management of choledocholithiasis, it is incumbent for the treating surgeon to be well versed in all manners of therapy currently available. The objective of this review is to provide an evidence-based summary of the contemporary management of choledocholithiasis.

Clip migration complicated by choledocholithiasis after laparoscopic biliary surgery: a report of four cases.

BACKGROUND: Migration of tissue clips into the common bile duct and formation of common bile duct stones after laparoscopic biliary surgery are extremely rare complications, and their etiologies remain elusive. We herein report four cases of migrated clips complicated by stones after laparoscopic biliary surgery. CASE PRESENTATION: Two patients (72- and 62-year-old women) were admitted because of varying degrees of epigastric pain, and two patients (88- and 69-year-old men) were admitted because of epigastric pain with chills and fever. They had previously undergone laparoscopic cholecystectomy (LC) plus laparoscopic common bile duct exploration (LCBDE) in our hospital. In Cases 1, 2, and 4, surgery revealed gallbladder triangle adhesion, inflamed dilated bile ducts, and fragile tissues. Blood tests showed elevated liver enzymes and bilirubin. Imaging indicated common bile duct stones. All patients underwent successful surgery with Hem-o-lok clips. No postoperative pain recurred. CONCLUSION: Clip migration after laparoscopic biliary surgery may be associated with preoperative biliary duct inflammation, improper use of tissue clips, and postoperative biliary leak-induced inflammation. The clinical presentation is similar to that of calculous cholangitis. Once symptoms of cholangitis appear in patients with a history of LC or LCBDE, the possibility of clip migration and stone formation should be considered.

The use of serum alkaline phosphatase as a choledocholithiasis marker to mitigate the cost of magnetic resonance cholangiography.

OBJECTIVE: To assess the predictive value of preoperative serum laboratory test results for identifying choledocholithiasis and reduce the use of cholangioresonance and its inherent costs. METHODS: Patients aged 21-69 years who underwent preoperative cholangioresonance examination at our institute were included. Patients with a history of fluctuating jaundice or biliary pancreatitis, bile duct dilatation on ultrasonography, and elevated levels of canalicular enzymes (alkaline phosphatase >100U/L and gamma-glutamyl transferase >50U/L) underwent cholangioresonance-guided surgery. Cases of choledocholithiasis confirmed by cholangioresonance were compared with those without choledocholithiasis. Serum laboratory data were evaluated and the diagnostic capabilities of these examinations were analyzed. RESULTS: A total of 104 patients were included. For detecting choledocholithiasis using alkaline phosphatase, the cut-off point was 78U/L, sensitivity was 97.6% (95%CI: 87.4-99.9), and specificity was 72.6% (95%CI: 59.8-83.1). In the binary logistic regression analysis, age (OR= 0.92; 95%CI: 0.86-0.98) and alkaline phosphatase level (OR= 1.02; 95%CI: 1.01-1.05) were selected for the final model. CONCLUSION: Serum alkaline phosphatase levels may aid preoperative diagnosis of asymptomatic choledocholithiasis. After a global clinical assessment of the patient, serum laboratory findings may contribute to a reduction in cholangioresonance-related heathcare costs.

Preoperative MRCP Can Rule Out Choledocholithiasis in Acute Cholecystitis with a High Negative Predictive Value: Prospective Cohort Study with Intraoperative Cholangiography.

BACKGROUND: Magnetic resonance cholangiopancreatography (MRCP) provides a noninvasive and fast modality for imaging the biliary tree when choledocholithiasis is suspected. Guidelines suggest that MRCP is recommended when strong or moderate signs of common bile duct (CBD) stones are present. Well-performed prospective studies are scarce regarding the sensitivity and specificity of preoperative MRCP in patients with acute cholecystitis in comparison with intraoperative cholangiography, ERCP, or choledochoscopy. METHODS: We performed a prospective, observational population-based feasibility study in Central Finland Hospital Nova between January 2019 and December 2019. We examined the diagnostic performance of preoperative MRCP on consecutive patients with acute cholecystitis scheduled for index admission cholecystectomy. The accuracy of MRCP was verified with IOC, choledochoscopy, or ERCP. The interobserver reliability of the image quality of MRCP and the sensitivity and specificity of choledocholithiasis were observed independently by three experienced radiologists. RESULTS: A total of 180 consecutive patients diagnosed with acute cholecystitis followed by index admission cholecystectomy were identified. MRCP was performed in 113/180 (62.8%) patients, and complementary perioperative imaging of the bile ducts was performed in 72/113 (63.7%) patients. The incidence of choledocholithiasis was high (29.2%). In acute cholecystitis, the sensitivity (76.2-85.7%) and specificity (84.3-92.2%) of MRCP were equally compared to the literature with unselected patient groups. The best visibility was observed in the common hepatic duct, the inferior CBD, and the central hepatic duct. The interobserver reliability was excellent for determining the size and quantity of CBD stones. CONCLUSION: In acute cholecystitis, MRCP yields high negative predictive value regarding detection of choledocholithiasis. If CBD stones were discovered, the interobserver reliability was excellent when measuring the size and number of CBD stones. The best-visualized area was the distal part of the biliary tract, which provides good preoperative workup if choledocholithiasis is present.

Machine learning to predict pediatric choledocholithiasis: A Western Pediatric Surgery Research Consortium retrospective study.

BACKGROUND: The purpose of this study was to accurately predict pediatric choledocholithiasis with clinical data using a computational machine learning algorithm. METHODS: A multicenter retrospective cohort study was performed on children <18 years of age who underwent cholecystectomy between 2016 to 2019 at 10 pediatric institutions. Demographic data, clinical findings, laboratory, and ultrasound results were evaluated by bivariate analyses. An Extra-Trees machine learning algorithm using k-fold cross-validation was used to determine predictive factors for choledocholithiasis. Model performance was assessed using the area under the receiver operating characteristic curve on a validation dataset. RESULTS: A cohort of 1,597 patients was included, with an average age of 13.9 ± 3.2 years. Choledocholithiasis was confirmed in 301 patients (18.8%). Obesity was the most common comorbidity in all patients. Choledocholithiasis was associated with the finding of a common bile duct stone on ultrasound, increased common bile duct diameter, and higher serum concentrations of aspartate aminotransferase, alanine transaminase, lipase, and direct and peak total bilirubin. Nine features (age, body mass index, common bile duct stone on ultrasound, common bile duct diameter, aspartate aminotransferase, alanine transaminase, lipase, direct bilirubin, and peak total bilirubin) were clinically important and included in the machine learning algorithm. Our 9-feature model deployed on new patients was found to be highly predictive for choledocholithiasis, with an area under the receiver operating characteristic score of 0.935. CONCLUSION: This multicenter study uses machine learning for pediatric choledocholithiasis. Nine clinical factors were highly predictive of choledocholithiasis, and a machine learning model trained using medical and laboratory data was able to identify children at the highest risk for choledocholithiasis.

ERCP findings provide further justification for a "surgery-first" mindset in choledocholithiasis.

INTRODUCTION: Choledocholithiasis is most often managed in a two-procedure pathway including endoscopic retrograde cholangiopancreatography (ERCP) followed by laparoscopic cholecystectomy (LC). In contrast, a single-stage, surgery-first approach consisting of LC, cholangiogram, and laparoscopic common bile duct exploration (LCBDE) is associated with reduced hospital stays and equivalent morbidity. Despite this, nationwide referral patterns heavily favor ERCP, obscuring those undergoing ERCP with obstructions amenable to simple intraoperative interventions. We hypothesized that most patients had endoscopic findings consistent with simple sludge or small-to-medium stones, which could have been cleared by basic LCBDE maneuvers. METHODS: We retrospectively reviewed 294 patients > 18 years old who underwent preoperative ERCP for the management of suspected choledocholithiasis. Exclusion criteria included: failed ERCP, cholangitis, prior cholecystectomy, patient refusal of surgery, or medical conditions precluding surgical candidacy. Stone size was categorized as small (0-4 mm), medium (5-7 mm), and large (≥ 8 mm). RESULTS: At the time of ERCP, 37 (20.1%) patients had sludge only, 96 (52.2%) had stones only, 42 (22.8%) had sludge and stones, and 9 (4.8%) had no stones. Of the 138 patients with any stones, 37 (26.8%) had small stones, 41 (29.7%) medium, 43 (31.2%) large, and 17 (12.3%) had uncharacterizable stones. Overall, 74.3% of patients had findings of sludge, stones (0-7 mm), or negative ERCP. CONCLUSION: The majority of patients who underwent preoperative ERCP for suspected choledocholithiasis had findings that are amenable to simple intraoperative interventions. In fact, over a quarter of the patients had a negative ERCP, sludge, or small stones which would likely be cleared by flushing/glucagon precluding any further instrumentation. While large stones may require more advanced techniques, this represents a small percentage of patients. Surgery-first management for suspected choledocholithiasis can offer an efficient alternative for the majority of patients.

The short- and long-term outcome after the surgical management of common bile duct stones in a tertiary referral hospital.

BACKGROUND: The removal of common bile duct stones by endoscopic retrograde cholangiopancreatography (ERCP) shows excellent results with low complication rates and is therefore considered a gold standard. However, in case of stones non-removable by ERCP, surgical extraction is needed. The surgical approach is still controversial and clinical guidelines are missing. This study aims to analyze the outcomes of patients treated with choledochotomy or hepaticojejunostomy for common bile duct stones. METHODS: All patients who underwent choledochotomy or hepaticojejunostomy for common bile duct stones at a tertiary referral hospital over 11 years were included. The analyzed data contains basic demographics, diagnostics, surgical parameters, length of hospitalization, and morbidity and mortality. RESULTS: Over the study period, 4375 patients underwent cholecystectomy, and 655 received an ERCP with stone extraction, with 48 of these patients receiving subsequent surgical treatment. ERCP was attempted in 23/30 (77%) of the choledochotomy patients pre/intraoperatively and 11/18 (56%) in hepaticojejunostomy patients. The 30-day major complication rate (Clavien-Dindo > II) was 1/30 (3%) in the choledochotomy group and 2/18 (11%) in the hepaticojejunostomy group. Complications after 30 days occurred in 3/30 (10%) patients and 2/18 (11%), respectively, and no mortality occurred. CONCLUSION: ERCP should still be considered the gold standard, although due to low short- and long-term morbidity rates, choledochotomy and hepaticojejunostomy represent effective surgical solutions for common bile duct stones.

Obstructive lithiasis of the lower bile duct discovered four decades after cholecystectomy and its management by ideal choledochotomy: a case report.

BACKGROUND: Residual lithiasis is the presence of stones in the common bile duct, ignored after one or more biliary interventions. We report an atypical case of chronic symptomatic lithiasis of the lower bile duct occurring 41 years after biliary surgery, managed successfully by ideal choledochotomy. CASE PRESENTATION: A 68-year-old Black African female with several past laparotomies including a cholecystectomy forty-one years ago presented with hepatic colic-type pain that had been intermittent for several years but worsened recently. Her clinical, biological, and imaging test assessments were suggestive of a residual obstructive lithiasis of the lower common bile duct. Through an open right subcostal laparotomy approach, a dilated bile duct of approximately 3 cm was found and managed by transverse choledochotomy in which the stone was extracted in retrograde manner. After confirmation of disobstruction, a primitive bile duct suture without biliary drainage was performed and a tubular drain was positioned under the liver. The postoperative course was uneventful at follow-up of 30 days. CONCLUSION: Residual choledocholithiasis can be avoided. We performed an ideal choledochotomy, of which the follow-up was simple.

TAVAC: choledochoscopy disposable scopes, and the single-stage vs. two-stage approach to choledocholithiasis.

BACKGROUND: Previous studies have been published evaluating the benefits and drawbacks of clearing the common bile duct of stones using a single-stage approach (LCBDE + LC) versus a two-stage approach (ERCP followed by LC). These studies have demonstrated that a single-stage approach offers similar outcomes and morbidities as a two-stage approach, with the added benefit of a lower cost and shorter length of stays. However, it is significant we understand why LCBDE is not commonly performed currently and also the lapse in surgical trainee exposure and competence in LCBDE. This paper aims to address the lapse in surgical trainee exposure to LCBDE, evaluate the scopes currently available to perform LCBDE, and review current data evaluating the risks and benefits of single-stage versus two-stage approaches to. METHODS: We utilized PubMed to analyze all publications related to the various disposable scopes utilized to perform choledochoscopy. We also discuss the need for disposable scopes and how this new market niche is transforming the choledochoscopy space. RESULTS: We analyzed the data related to single-stage and two-stage approach to choledocholithiasis. We noted an overall shorter length of stay and also decreased costs in favor of a single-stage approach. CONCLUSION: A single-stage LCBDE is the most cost-effective treatment option for choledocholithiasis in patients with choledocholithiasis undergoing a cholecystectomy. In addition, single-stage approach is associated with shorter length of stay. Knowledge of the available choledochoscopes and tools available to surgeons to perform choledochoscopy is significant. The evidence does support the use of disposable choledochoscope from a cost and cross-contamination perspective. Additionally, efforts should be made to incorporate LCBDE into the teaching paradigm of surgical training programs.

Gallstone Ileus With Persistent Cholelithiasis and Choledocholithiasis.

Gallstone ileus is an uncommon but well-described occurrence in general surgery. However, discrepancy regarding optimal surgical management with 1 or 2 stage operation is still debated. This case report presents a 73-year-old woman who presented to the emergency department (ED) with a small bowel obstruction due to a gallstone lodged in a portion of the proximal ileum. The patient was also noted to have persistent cholelithiasis and cholecystoduodenal fistula. A single-stage surgery involving enterolithotomy, cholecystectomy, fistula repair, and cholangioscopy was performed. The patient progressed well and was discharged home without recurrent symptoms. Therefore, in a hemodynamically stable patient with persistent cholelithiasis or choledocholithiasis, it is reasonable to perform a definitive single-stage operation.

Development and validation of a hybrid simulator for ultrasound-guided laparoscopic common bile duct exploration.

BACKGROUND: Ultrasound-guided laparoscopic common bile duct exploration (LCBDE) is the surgical management of choledocholithiasis. The procedure presents significant benefits to patients but still fails to be generalised because of the complex set of skills it requires. A simulator for ultrasound-guided LCBDE would allow trainee surgeons as well as experienced surgeons who perform this surgery seldomly to practice and gain confidence. METHODS: This article presents the development and validation of an easily reproducible hybrid simulator for ultrasound-guided LCBDE which integrates real and virtual components of the task. We first developed a physical model made of silicone. The fabrication technique is replicable and allows quick and easy production of multiple models. We then applied virtual components onto the model to create training for laparoscopic ultrasound examination. Combined with a commercially available lap-trainer and surgical equipment, the model can be used for training the fundamental steps of the surgery through the trans-cystic or trans-choledochal approaches. The simulator was evaluated through face, content, and construct validation. RESULTS: Two novices, eight middle grades, and three experts were recruited to test the simulator. The results of the face validation showed that the surgeons found the model realistic visually and felt realistic when performing the different steps of the surgery. The content validation indicated the usefulness of having a training system to practice the choledochotomy, the choledochoscopy and stone retrieval, and the suturing. The construct validation highlighted the ability of the simulator to differentiate between surgeons with various levels of expertise. CONCLUSIONS: The hybrid simulator presented is a low-cost yet realistic model which allows the surgeons to practice the technical skills required for trans-cystic and trans-choledochal ultrasound-guided LCBDE.