Simple biliary atresia score-a validated diagnostic aid for infantile cholestasis.

PURPOSE: The workup of jaundiced infants may be variable and protracted, thereby delaying the diagnosis and timely intervention for biliary atresia (BA). This potentially leads to inferior outcomes. We developed a practical score to stratify infantile cholestasis according to the risk of having BA. METHOD: The score (0-7) [gallbladder length ≤ 15 mm (+ 1), common bile duct (CBD) diameter < 0.5 mm(+ 1), pre-portal vein (PV) echogenicity(+ 1), direct-to-total bilirubin ratio (D/T) ≥ 0.7(+ 2), and gamma-glutamyl transferase (GGT) ≥ 200 IU/L(+ 2)] are derived from logistic regression of data from a retrospective cohort of cholestatic infants (n = 58, 41 BA) in our institution. It was then validated with a separate retrospective cohort (n = 28, 17 BA) from another institution. Final diagnoses were as per intraoperative cholangiogram (IOC) and liver histopathology. RESULTS: A cutoff score of ≥ 3 diagnosed BA with 100% and 94% sensitivity in the derivative cohort (area under receiver operating characteristic curve, AUROC 0.869) and validation cohort (AUROC 0.807), respectively. D/T ratio was the most sensitive (93%) and CBD diameter was the most specific (88%) parameter. The score accurately predicted non-BA in 11(65%) and 7(63%) infants in the derivative and validation cohorts, respectively, with one missed BA in the latter. CONCLUSION: We propose a validated, simple, yet sensitive diagnostic score to risk-stratify cholestatic infants, aiming to expedite definitive management of BA.

Percutaneous Biliary Interventions via the Modified Hutson Loop in Patients with Biliary-Enteric Anastomoses: A Retrospective Study.

PURPOSE: This study aimed to present the institutional experience and algorithm for performing biliary interventions in liver transplant patients using the modified Hutson loop access (MHLA) and the impact of percutaneous endoscopy via the MHLA on these procedures. METHODS: Over 13 years, 201 MHLA procedures were attempted on 52 patients (45 liver transplants; 24 living and 21 deceased donors) for diagnostic (e.g., cholangiography) and therapeutic (e.g., stent/drain insertion and cholangioplasty) purposes. The most common indications for MHLA were biliary strictures (60%) and bile leaks (23%). Percutaneous endoscopy was used to directly visualize the biliary-enteric anastomosis, diagnose pathology (e.g., ischemic cholangiopathy), and help in biliary hygiene (removing debris/casts/stones/stents) in 138/201 (69%) procedures. Technical success was defined as cannulating the biliary-enteric anastomosis and performing diagnostic/therapeutic procedure via the MHLA. RESULTS: The technical success rate was 95% (190/201). The failure rate among procedures performed with and without endoscopy was 2% (3/138) versus 13% (8/63) (P = 0.0024), and the need for new transhepatic access (to aid the procedure) was 12% (16/138) versus 30% (19/63) (P = 0.001). Despite endoscopy, failure in 2% of the cases resulted from inflamed/friable anastomosis (1/3) and high-grade stricture (2/3) obstructing retrograde cannulation of biliary-enteric anastomosis. Major adverse events (bowel perforation and injury) occurred in 1% of the procedures, with no procedure-related mortality. CONCLUSIONS: MHLA-based percutaneous biliary intervention is a safe and effective alternative to managing complications after liver transplant. Percutaneous endoscopy via the MHLA improves success rates and may reduce the need for new transhepatic access. Level of Evidence Level 4.

Efficacy of different indocyanine green doses in fluorescent laparoscopic cholecystectomy: A prospective, randomized, double-blind trial.

BACKGROUND AND OBJECTIVES: Intraoperative bile duct injury is a significant complication in laparoscopic cholecystectomy (LC). Near-infrared fluorescence cholangiography (NIFC) can reduce this complication. Therefore, determining the optimal indocyanine green (ICG) dosage for effective NIFC is crucial. This study aimed to determine the optimal ICG dosage for NIFC. METHODS: This was a prospective, randomized, double-blind clinical trial at a single tertiary referral center, including 195 patients randomly assigned to three groups: lower dose (0.01 mg/BMI) ICG (n = 63), medium dose (0.02 mg/BMI) ICG (n = 68), and higher dose (0.04 mg/BMI) ICG (n = 64). Surgeon satisfaction and detection rates for seven biliary structures were compared among the three dose groups. RESULTS: Demographic parameters did not significantly differ among the groups. The medium dose (72.1%) and higher dose ICG groups (70.3%) exhibited superior visualization of the common hepatic duct compared to the lower dose group (41.3%) (p < 0.001). No differences existed between the medium and higher dose groups. Similar trends were observed for the common bile duct and cystic common bile duct junction. CONCLUSIONS: In patients undergoing fluorescent laparoscopic cholecystectomy, the 0.02 mg/BMI dose of indocyanine green demonstrated better biliary structure detection rates than the 0.01 mg/BMI dose and was non-inferior to the 0.04 mg/BMI dose.

Outcomes of asymptomatic common bile duct stones detected at intraoperative cholangiography.

AIMS: The aim of this study was to investigate the outcome of common bile duct stones (CBDS) in asymptomatic patients at laparoscopic cholecystectomy (LC) and intra-operative cholangiogram (IOC). METHODS: All patients undergoing LC and IOC at Te Whatu Ora - Health New Zealand Waikato between January 2017 and January 2022 were retrospectively reviewed. Electronic records were screened for asymptomatic CBDS. Exclusion criteria were hyperbilirubinaemia, gallstone pancreatitis, cholangitis and imaging-detected CBDS. IOC reports were reviewed to determine presence of CBDS. A second blinded review was undertaken by a radiologist. Outcomes were use of endoscopic retrograde pancreatography (ERCP), complications and readmission with retained CBDS. RESULTS: Included were 1,297 patients undergoing LC and IOC. Of these, 150 (24.1%) patients had a positive IOC, of which 58 (38.7%) were asymptomatic. Attempted flushing of CBDS was employed in 49 cases, 10 successfully. Common duct exploration was successful in a further six out of seven cases. Of the remaining 42 patients, 18 were offered ERCP. Seven had no stone at endoscopy. Sixteen had imaging, revealing clear ducts in 14. The remaining two then had ERCP confirming choledocholithiasis. Eight patients were managed expectantly, of whom none required readmission with retained stones. CONCLUSION: Rates of retained asymptomatic stones after positive IOC were low. Acknowledging risks associated with intervention and low rates of readmission with retained CBDS, an expectant approach could be more readily considered.

Determining the patency of biliary tracts in dogs with gallbladder mucocele using near-infrared cholangiography with indocyanine green.

Cholecystectomy is indicated for gallbladder mucoceles (GBM). Evaluating the patency of the biliary duct and precise biliary tree visualization is crucial for reducing the risk of compromised bile flow after surgery. Therefore, intraoperative cholangiography (IOC) is recommended during cholecystectomy to prevent biliary tract injury. Although indocyanine green (ICG) cholangiography has been extensively reported in human medicine, only one study has been conducted in veterinary medicine. Therefore, this study aimed to demonstrate the use of ICG for IOC to identify fluorescent biliary tract images and determine the patency of the common bile duct during cholecystectomy in dogs. This study comprised 27 dogs, consisting of 17 with gallbladder mucoceles (GBM) and 10 controls, specifically including dogs that had undergone elective cholecystectomy for GBM. ICG injection (0.25 mg/kg) was administered intravenously at least 45 minutes before surgery. During the operation, fluorescent images from cholangiography were displayed on the monitor and obtained in black-and-white mode for the comparison of fluorescence intensity (FI). The FI values of the gallbladders (GBs) and common bile duct (CBD) were measured using FI analyzing software (MGViewer V1.1.1, MetapleBio Inc.). The results demonstrated successful CBD patency identification in all cases. Mobile GBM showed partial gallbladder visibility, whereas immobile GBM showed limited visibility. Additionally, insights into the adequate visualization of the remaining extrahepatic biliary tree anatomy were provided, extending beyond the assessment of CBD patency and gallbladder intensity. Our study demonstrates the potential of fluorescent IOC using intravenous injection of ICG for assessing the patency of the cystic duct and common bile duct during cholecystectomy in patients with GBM, eliminating the need for surgical catheterization and flushing of the biliary ducts. Further research is warranted to investigate and validate the broader applicability of ICG cholangiography in veterinary medicine.

Using neural networks to autonomously assess adequacy in intraoperative cholangiograms.

BACKGROUND: Intraoperative cholangiography (IOC) is a contrast-enhanced X-ray acquired during laparoscopic cholecystectomy. IOC images the biliary tree whereby filling defects, anatomical anomalies and duct injuries can be identified. In Australia, IOC are performed in over 81% of cholecystectomies compared with 20 to 30% internationally (Welfare AIoHa in Australian Atlas of Healthcare Variation, 2017). In this study, we aim to train artificial intelligence (AI) algorithms to interpret anatomy and recognise abnormalities in IOC images. This has potential utility in (a) intraoperative safety mechanisms to limit the risk of missed ductal injury or stone, (b) surgical training and coaching, and (c) auditing of cholangiogram quality. METHODOLOGY: Semantic segmentation masks were applied to a dataset of 1000 cholangiograms with 10 classes. Classes corresponded to anatomy, filling defects and the cholangiogram catheter instrument. Segmentation masks were applied by a surgical trainee and reviewed by a radiologist. Two convolutional neural networks (CNNs), DeeplabV3+ and U-Net, were trained and validated using 900 (90%) labelled frames. Testing was conducted on 100 (10%) hold-out frames. CNN generated segmentation class masks were compared with ground truth segmentation masks to evaluate performance according to a pixel-wise comparison. RESULTS: The trained CNNs recognised all classes.. U-Net and DeeplabV3+ achieved a mean F1 of 0.64 and 0.70 respectively in class segmentation, excluding the background class. The presence of individual classes was correctly recognised in over 80% of cases. Given the limited local dataset, these results provide proof of concept in the development of an accurate and clinically useful tool to aid in the interpretation and quality control of intraoperative cholangiograms. CONCLUSION: Our results demonstrate that a CNN can be trained to identify anatomical structures in IOC images. Future performance can be improved with the use of larger, more diverse training datasets. Implementation of this technology may provide cholangiogram quality control and improve intraoperative detection of ductal injuries or ductal injuries.

A Pilot Study for Biliary Atresia Diagnosis: Fluorescent Imaging of Indocyanine Green in Stool.

BACKGROUND: Biliary atresia is the most common cause of obstructive jaundice in infants and conventional cholangiography is the current diagnostic gold standard. Fluorescent cholangiography with indocyanine green can enhance biliary tree visualization during surgery because it is exclusively excreted into the bile ducts and eventually into the intestine. Therefore, we hypothesized that indocyanine green presence in stool could confirm bile duct patency in infants. METHODS: A prospective single center cohort study was performed on infants (age ≤ 12 months) with and without jaundice after obtaining IRB approval. Indocyanine green was administered intravenously (0.1 mg/kg). Soiled diapers collected post-injection were imaged for fluorescence. RESULTS: After indocyanine green administration, fluorescence was detected in soiled diapers for control patients (n = 4, x = 14 h22 m post-injection) and jaundiced patients without biliary atresia (n = 11, x = 13 h28 m post-injection). For biliary atresia patients (n = 7), post-injection soiled diapers before and after Kasai portoenterostomy were collected. Fluorescence was not detected in stool from 6 of 7 biliary atresia patients. As a test, indocyanine green detection in stool was 97% accurate for assessing biliary patency. CONCLUSION: Fluorescent Imaging for Indocyanine Green (FIInd Green) in stool is a fast and accurate approach to assess biliary patency non-invasively in infants. LEVEL OF EVIDENCE: Level III.

Novel navigation for laparoscopic cholecystectomy fusing artificial intelligence and indocyanine green fluorescent imaging.

This preliminary study is the first to demonstrate that AI can precisely identify loose connective tissue during laparoscopic cholecystectomy and ICG fluorescent cholangiography. Tashiro and colleagues conclude that this novel real-time navigation modality fusing AI and ICG fluorescent imaging may enhance safety and provide more reliable laparoscopic or robotic surgery.

[Clinical and economic justification of icg-cholangiography in «difficult¼ laparoscopic cholecystectomy]. / Kliniko-ekonomicheskoe obosnovanie kholangiografii s indotsianinom zelenym pri «trudnoi¼ laparoskopicheskoi kholetsistektomii.

OBJECTIVE: To prove from a clinical and economic point of view the expediency of using ICG cholangiography in patients with «difficult¼ laparoscopic cholecystectomy for the prevention of damage to the bile ducts. MATERIAL AND METHODS: The results of treatment of 173 patients with cholelithiasis at various levels of health care providing were analyzed with regard to assessment of indicators of surgery complexity, developed complications and economic costs. RESULTS: The effectiveness of the original scale of «difficult¼ laparoscopic cholecystectomy has been proved. The financial and economic costs of treatment of patients with damage of biliary ducts and patients with cholelithiasis without development of complications have been analyzed and evaluated. A comparative description of financial costs for patients with «difficult¼ laparoscopic cholecystectomy with the use of ICG-cholangiography has been given. A program on care delivery for patients suffering from cholelithiasis in the conditions of region with regard to safety and economic effectiveness has been developed. CONCLUSION: The implementation of this program provides the minimization of postoperative complications and fatality at all levels of surgical care delivery. It has been established that a rational approach to reducing the number of biliary ducts damages is their prevention by prediction of «difficult¼ laparoscopic cholecystectomy and performance of such interventions in medical organizations of III level with the possibility of modern technologies use.

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.

Utility of enteral nutrition via percutaneous transhepatic cholangiography drainage catheterization in late-stage malignant obstructive jaundice.

Objective: The purpose of this study was to explore the clinical benefits of establishing an enteral nutrition (EN) pathway via percutaneous transhepatic cholangiography drainage (PTCD) catheterization in patients with late-stage malignant obstructive jaundice (MOJ).Methods: We selected 30 patients diagnosed as having late-stage MOJ with malnutrition. A dual-lumen biliary-enteral nutrition tube was placed via PTCD along with a biliary stent implantation. Postoperative EN was provided, and we observed the time taken for tube placement, its success rate, complications, and therapeutic efficacy.Results: Tube placement was successful in all 30 patients with an average procedural time of 5.7 ± 1.4 min with no tube placement complications. Compared to preoperative measures, there was a significant improvement in postoperative jaundice reduction and nutritional indicators one month after the procedure (p < 0.05). Post-placement complications included tube perileakage in 5 cases, entero-biliary reflux in 4 cases, tube blockage in 6 cases, tube displacement in 4 cases, accidental tube removal in 3 cases, and tube replacement due to degradation in 8 cases, with tube retention time ranging from 42 to 314 days, averaging 124.7 ± 37.5 days. All patients achieved the parameters for effective home-based enteral nutrition with a noticeable improvement in their quality of life.Conclusion: In this study, we found that the technique of establishing an EN pathway via PTCD catheterization was minimally invasive, safe, and effective; the tube was easy to maintain; and patient compliance was high. It is, thus, suitable for long-term tube retention in patients with late-stage MOJ.

Donor bile duct evaluation with magnetic resonance cholangiography in living-donor liver transplantation: a novel anatomical classification for predicting surgical techniques.

PURPOSE: To propose a novel, inclusive classification that facilitates the selection of the appropriate donor and surgical technique in living-donor liver transplantation (LDLT). METHODS: The magnetic resonance cholangiography examinations of 201 healthy liver donors were retrospectively evaluated. The study group was classified according to the proposed classification. The findings were compared with the surgical technique used in 93 patients who underwent transplantation. The Couinaud, Huang, Karakas, Choi, and Ohkubo classifications were also applied to all cases. RESULTS: There were 118 right-lobe donors (58.7%) and 83 left-lateral-segment donors (41.3%). Fifty-six (28.8%) of the cases were classified as type 1, 136 (67.7%) as type 2, and 7 (3.5%) as type 3 in the proposed classification; all cases could be classified. The number of individuals able to become liver donors was 93. A total of 36 cases were type 1, 56 were type 2, and 1 was type 3. Of the type 1 donors, 83% required single anastomosis during transplantation, whereas six patients classified as type 1 required two anastomoses, all of which were caused by technical challenges during resection. Moreover, 51.8% of the cases classified as type 2 required additional anastomosis during transplantation. The type 3 patient required three anastomoses. The type 1 and type 2 donors required a different number of anastomoses (P < 0.001). CONCLUSION: The proposed classification in this study includes all anatomical variations. This inclusive classification accurately predicts the surgical technique for LDLT.

Indocyanine green fluorescent cholangiography: The new standard practice to perform laparoscopic cholecystectomy in pediatric patients. A comparative study with conventional laparoscopic technique.

BACKGROUND: This study aimed to compare outcomes of standard laparoscopic cholecystectomy and indocyanine green fluorescent cholangiography laparoscopic cholecystectomy over a 10-year period. METHODS: From 2013 to 2023, 173 laparoscopic cholecystectomies were performed in 2 pediatric surgery units: 83 using standard technique (G1) and 90 using indocyanine green fluorescent cholangiography (G2). Patients included 96 girls and 77 boys, with a median age of 12.3 years (range 4-17) and a median weight of 51 kg (range 19-114). The 2 groups were compared regarding the following: (1) perioperative complications rate; (2) overall length of surgery (T1); (3) length of cystic duct isolation, clipping, and sectioning (T2); (4) time of gallbladder removal (T3); (5) degree of visualization of biliary tree; (6) safety and feasibility of indocyanine green fluorescent cholangiography; (7) incidence of anatomical anomalies detected intraoperatively. RESULTS: All laparoscopic cholecystectomies were accomplished without conversion to open. The perioperative complications rate was significantly higher in G1 compared with G2 (12% vs 0%; P = .0007). Median T1, T2, and T3 were significantly longer in G1 (90, 37, 35 minutes) compared with G2 (55, 17, 19 minutes) (P = .0001), respectively. The visualization rate of the complete biliary tree was significantly higher in G2 (98.8%) than in G1 (80.7%) (P = .0001). No adverse reactions to indocyanine green were recorded. The incidence of biliary anomalies detected intraoperatively was significantly higher in G2 (7.8%) than in G1 (1.2%) (P = .03). CONCLUSION: Indocyanine green fluorescent cholangiography can be considered the new standard practice to perform laparoscopic cholecystectomy in pediatrics. Indocyanine green fluorescence provided superior visualization of biliary anatomy, increased detection of anatomic variants, faster procedure, and fewer complications compared with conventional technique. Indocyanine green fluorescent cholangiography was safe, feasible, simple, inexpensive, and a timesaving tool.

Near-infrared indocyanine green fluorescent cholangiography in urgent and emergency laparoscopic cholecystectomy: a preliminary study after propensity score-matched study.

INTRODUCTION: Bile duct injury is a major complication of laparoscopic cholecystectomy (LC). Indocyanine green near-infrared fluorescence cholangiography (ICG-NIFC) is a well-recognized technique who provides an intraoperative mapping of the biliary system. METHODS: All patients underwent urgent LC and randomly divided into two groups: in one group, only white light imaging was used and, in the ICG group, ICG was used. Due to the heterogeneity of our groups, a PSM was performed with a 1:1 PSM cohort. RESULTS: The use of ICG clearly decreases the operation time (p value 0.002). The overall rate of intra- and post- operative complications was 4.17% and 15.8% respectively. Post-operative biliary duct injury trend decreases in ICG group and after the homogenization of the 2 cohorts, the intra- and post- operative complications (including vascular and biliary duct injury) results changed with a highest rate of complication in the cohort with no-ICG administration. The use of NIFC demonstrated a protective effect against intra- and post- operative complications and biliary duct injury (HR 0.037, p value 0.337 and HR 0.039, p value 0.647; HR 0.288; p value 0.05 and HR 0.635; p value 0.687, respectively). CONCLUSIONS: The intra-operative use of NIFC showed a trend in the reduction of the rate of intra- and post-operative complications, the duration of surgery, and the length of hospital stay. ICG is a highly safe approach to urgent and emergency LC, as for elective LC, and could lead the surgeon to conduct the procedure more efficiently.

Safety of laparoscopic cholecystectomy performed by trainee surgeons with different cholangiographic techniques (SCOTCH): a prospective non-randomized trial on the impact of fluorescent cholangiography during laparoscopic cholecystectomy performed by trainees.

AIMS: The identification of the anatomical components of the Calot's Triangle during laparoscopic cholecystectomy (LC) might be challenging and its difficulty may increase when a surgical trainee (ST) is in charge, ultimately allegedly affecting also the incidence of common bile duct injuries (CBDIs). There are various methods to help reach the critical view of safety (CVS): intraoperative cholangiogram (IOC), critical view of safety in white light (CVS-WL) and near-infrared fluorescent cholangiography (NIRF-C). The primary objective was to compare the use of these techniques to obtain the CVS during elective LC performed by ST. METHODS: This was a multicentre prospective observational study (Clinicalstrials.gov Registration number: NCT04863482). The impact of three different visualization techniques (IOC, CVS-WL, NIRF-C) on LC was analyzed. Operative time and time to achieve the CVS were considered. All the participating surgeons were also required to fill in three questionnaires at the end of the operation focusing on anatomical identification of the general task and their satisfaction. RESULTS: Twenty-nine centers participated for a total of 338 patients: 260 CVS-WL, 10 IOC and 68 NIRF-C groups. The groups did not differ in the baseline characteristics. CVS was considered achieved in all the included case. Rates were statistically higher in the NIR-C group for common hepatic and common bile duct visualization (p = 0.046; p < 0.005, respectively). There were no statistically significant differences in operative time (p = 0.089) nor in the time to achieve the CVS (p = 0.626). Three biliary duct injuries were reported: 2 in the CVS-WL and 1 in the NIR-C. Surgical workload scores were statistically lower in every domain in the NIR-C group. Subjective satisfaction was higher in the NIR-C group. There were no other statistically significant differences. CONCLUSIONS: These data showed that using NIRF-C did not prolong operative time but positively influenced the surgeon's satisfaction of the performance of LC.

[Modern possibilities of fluorescent imaging in liver surgery]. / Sovremennye vozmozhnosti flyuorestsentnoi vizualizatsii v khirurgii pecheni.

The article presents a literature review of modern methods of fluorescent navigation in liver surgery. The technique of tumor «staining¼, mapping of liver segments, fluorescent cholangiography is covered. The own results of the use of indocyanine green in liver surgery are presented.

[Integration of ICG-fluorescence cholangiography into the safety system of laparoscopic cholecystectomy]. / Integratsiya ICG-fluorestsentnoi kholangiografii v sistemu bezopasnosti laparoskopicheskoi kholetsistektomii.

THE AIM OF THE STUDY: Is evaluating the possibility of integrating ICG-fluorescent cholangiography into the general safety system for laparoscopic cholecystectomy to prevent damage to the extrahepatic bile ducts by working out the methodological aspects of navigation technologies. MATERIALS AND METHODS: The analysis of literature data on various approaches to improve the perioperative identification of anatomical structures during laparoscopic cholecystectomy, including the ICG-fluorescent cholangiography, was carried out. This program was implemented during the provision of elective surgical care to 24 patients with cholelithiasis who underwent laparoscopic cholecystectomy with ICG-fluorescent navigation. RESULTS AND DISCUSSION: The developed program included: preoperative assessment of the anatomy of the biliary tree using MRCP; intraoperative technique of safe laparoscopic cholecystectomy with mandatory application of the concept of «critical view of safety¼ (CVS), which allows the most effective identification of the necessary anatomical structures; the use of ICG-fluorescent cholangiography, which allows to improve the control of anatomical structures at all stages of the operations. CONCLUSIONS: The first experience of using ICG-fluorescent cholangiography testifies to the high informative value of the method, the possibility and prospects of integrating the technology into a comprehensive safety system during laparoscopic cholecystectomy.