Incidence and management of choledocholithiasis on routine intraoperative cholangiogram: a 5-year tertiary centre experience

The Impact of Intraoperative Glucagon on the Diagnostic Accuracy of Intraoperative Cholangiogram for the Diagnosis of Choledocholithiasis: Experience from a Large Tertiary Care Center

A proportion of patients who undergo intraoperative cholangiogram (IOC) do not have bile duct stones at the time of endoscopic retrograde cholangiopancreatography (ERCP), either due to the spontaneous passage of stones or a false-positive IOC. Glucagon has been utilized as an inexpensive tool to allow the passage of micro-choledocholithiasis to the duodenum and resolve filling defects caused by stones or air bubbles. The purpose of our study is to understand the change in diagnostic accuracy of IOC to detect choledocholithiasis with intraoperative glucagon. We conducted a retrospective study at a tertiary care center on adult patients who underwent laparoscopic cholecystectomy with IOC. The diagnostic accuracy of IOC was assessed before and after the administration of intravenous glucagon. Of 1455 patients, 374 (25.7%) received intraoperative glucagon, and 103 of these 374 patients (27.5%) showed resolution of the filling defect with the passage of contrast to the duodenum. Pre- and post-glucagon administration comparison showed enhancement in specificity from 78% to 83%, an increase in positive predictive value from 67.3% to 72.4%, and an improvement in the diagnostic accuracy of IOC from 81.5% to 84.3%. Our findings suggest that intraoperative glucagon administration carries the potential to reduce the rate of false-positive IOCs, thereby reducing the performance of unnecessary ERCPs.

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.

Is Routine Intraoperative Cholangiogram Necessary in Patients With Mild Acute Biliary Pancreatitis Undergoing Index Admission Cholecystectomy?

Background: There is controversy about whether intraoperative cholangiogram (IOC) should be performed routinely during laparoscopic cholecystectomy for patients with acute biliary pancreatitis, given significant false positive and negative rates and increased resource utilization. The aim of this study was to clarify the role of IOC in cases of mild biliary pancreatitis in patients undergoing index admission cholecystectomy, its impact on patient outcomes, and the impact of blood tests, imaging, and preoperative intervention on the detection of choledocholithiasis.Methods: A retrospective review of all patients presenting with acute mild biliary pancreatitis between January 2006 and December 2019 was conducted. Data collected included patient demographics, serum chemistry, IOC, and Endoscopic Retrograde Cholangiopancreatography (ERCP) findings, imaging findings, length of stay, operative length, and long-term follow-up outcomes.Results: 284 patients met the inclusion criteria for the study. The overall false positive IOC rate was 7.4%. Worsening bilirubin trend was a positive predictive value (PPV) for positive IOC and ERCP outcomes with a relative risk of 2.93 (P < .01) and 2.32 (P = .013), respectively. Improving preoperative bilirubin trend had a significant negative predictive value in IOC with a relative risk of .59 (P = .02). Positive IOC was shown to significantly increase operative length with a relative risk of 2.03 (P < .001).Discussion: A rising preoperative bilirubin is a predictor of a positive IOC and patients with normalizing bilirubin levels or a preoperative ERCP are less likely to have choledocholithiasis. These features may be used to select patients that would benefit from an IOC for index admission cholecystectomy.

Choledocholithiasis: A Review of Management and Outcomes in a Regional Setting

Background Choledocholithiasis is a common surgical presentation with an incidence of 8% to 16% in symptomatic cholelithiasis. Treatment often requires a multi-stage approach via endoscopic retrograde cholangiopancreatography (ERCP) and laparoscopic cholecystectomy (LC), which can prolong the length of stay (LoS) and expose patients to unnecessary risks. A single-stage procedure, such as LC with common bile duct exploration (CBDE), is a safe and effective option that may decrease LoS. This study compares patient outcomes and management in a regional center and aims to identify factors that predict the presence of confirmed choledocholithiasis. Methods A retrospective cross-sectional analysis was performed on all patients admitted to Toowoomba Hospital for management of diagnosed or suspected choledocholithiasis from January 2021 to March 2023. Patient demographics, ERCP findings, and operative data were collated. Results A total of 195 patients were identified, including 136 patients undergoing multi-stage management, 34 patients who had an ERCP alone, and 25 patients who underwent single-stage management. Single-stage procedures had an 80% success rate with an average LoS of 3.6 days. Multi-stage procedures had an average LoS of 8.1 days and an ERCP success rate of 93%. Complication rates between ERCP (11.7%) and LC with CBDE (9.7%) were comparable. Time to index ERCP and serum bilirubin level were found to be significantly lower in those with positive index ERCP findings compared to those without. Conclusion Single-stage procedures are a safe way to manage choledocholithiasis and are associated with a reduced LoS when compared to multi-stage management, with comparable efficacy and morbidity rates.

Significance of intra-operative cholangiogram and its application in suspected duodenal injuries - Case report

INTRODUCTION AND IMPORTANCE

Intraoperative cholangiogram has always been a critical procedure that allows identification of biliary anatomy, thereby reducing the risks of bile duct injuries.

CASE PRESENTATION

We present a unique case where the intraoperative cholangiogram highlighted a suspected duodenal injury.

CLINICAL DISCUSSION

This case discusses the intraoperative steps taken to ensure there was no injury, highlight the importance of cholangiogram interpretation as a skill for all surgeons.

CONCLUSION

Intraoperative cholangiogram is a crucial procedure to highlight both biliary and non-biliary anatomy and can be used to identify duodenal injuries as was assessed in our case.