BACKGROUND: Prior typing methods fail to provide predictive insights into surgical complexities for extrahepatic choledochal cyst (ECC). This study aims to establish a new classification system for ECC through clustering of imaging results. Additionally, it seeks to compare the differences among the identified ECC types and assess the levels of surgical difficulty.
METHODS: The imaging data of 124 patients were automatically grouped through a K-means clustering analysis. According to the characteristics of the new grouping, corrections and interventions were carried out to establish a new classification. Demographic data, clinical presentations, surgical parameters, complications, reoperation, and prognostic indicators were analyzed according to different types. Factors contributing to prolonged surgical time were also evaluated.
RESULTS: A new classification system of ECC: Type A (upper segment), Type B (middle segment), Type C (lower segment), and Type D (entire bile duct). The incidences of comorbidities (calculus or infection) were significantly different (P=0.000, P=0.002). Additionally, variations in the incidence of postoperative cholangitis were statistically significant (P=0.046). The operative time was significantly different between groups (P=0.001). Age, BMI > 30, classification, and the presence of combined stones exhibit a significant association with prolonged operative time (P=0.002, P=0.000, P=0.011, P=0.011).
CONCLUSIONS: In conclusion, our utilization of machine learning-driven cluster analysis has enabled the creation of a novel extrahepatic biliary dilatation typology. This classification, in conjunction with factors like age, combined stone occurrence, and obesity, significantly influences the complexity of laparoscopic choledochal cyst surgery, offering valuable insights for improved surgical treatment.

The choledochal cyst (CC) can be better termed as biliary tract malformation because of the close association of embryology and etiology in the causation of CC. Contrary to Babbitt\'s postulation of reflux, damage and dilatation, reflux was not demonstrable as the causative factor in all varieties of CC. High pressure in the biliary system, otherwise termed ductal hypertension, is put forth as an alternative to explain the evolution of CC. The forme fruste type, which does not find a place in the standard classification, typifies the ductal hypertension hypothesis. Hence a closer, in-depth review would be able to highlight this apt terminology of biliary tract malformation.

BACKGROUND: Matrix metalloproteinase-7 (MMP-7) is associated with biliary injury. This study aimed to evaluate the relationships of serum MMP-7 with clinical characteristics in choledochal cysts (CDC) children.
METHODS: Between June 2020 and July 2022, we conducted a prospective study of CDCs who underwent one-stage definitive operation at our center. Serum MMP-7 was measured using an enzyme-linked immunosorbent assay. We evaluated the relationships between serum MMP-7 and age, laboratory tests, imaging examinations, liver fibrosis, MMP-7 expression, and perforation.
RESULTS: A total of 328 CDCs were enrolled in the study, with a median serum MMP-7 of 7.67 ng/mL. Higher serum MMP-7 was correlated with younger age at diagnosis (p < 0.001), larger cyst sizes (p < 0.001), higher liver fibrosis stages (p < 0.001), and higher incidence of perforation (p < 0.01). Liver MMP-7 was mainly expressed in intrahepatic and extrahepatic biliary epithelial cells. The area under the receiver operating characteristic curve (AUROC) was 0.630 (p < 0.001) for serum MMP-7 in predicting perforation. When serum MMP-7 was combined with γ-glutamyl transferase (GGT), the AUROC increased to 0.706 (p < 0.001).
CONCLUSIONS: Serum MMP-7 was associated with biliary obstruction in CDCs. Patients with high serum MMP-7 were more likely to have severe liver damage and biliary injury, with higher incidences of liver fibrosis and perforation.

UNASSIGNED: The aim is to study the various histopathological changes in the liver in pediatric patients with choledochal cyst (CC) and correlate with the presentation and type of cyst.
UNASSIGNED: In a prospective observational study including all pediatric patients who underwent CC excision, histopathological changes of the liver in the form of cholestasis (CHS), portal inflammation (PI), bile duct proliferation (BDP), and fibrosis were studied and graded using a scoring system. They were analyzed in relation to age, sex, symptoms, and type of the cyst.
UNASSIGNED: All 30 patients of CC showed various degrees of histopathological changes in the liver in the form of CHS, PI, BDP, and liver fibrosis. Patients <1 years had 9/13 (69.2%) cystic variety and those >1 years had 17/17 (100%) fusiform variety of CC (P < 0.001). Patients <1 years frequently presented with jaundice and hepatomegaly and those >1 years presented with pain abdomen (P < 0.002). Higher grades of liver fibrosis and BDP were seen in the cystic variety compared to the fusiform variety (P < 0.001). However, no significant association was found with CHS and PI (P > 1.23).
UNASSIGNED: Histopathological changes in the liver of varying grades are seen in all patients of CC. Patients of CC <1 year presented frequently with jaundice, had the cystic type, and had a higher degree of liver damage on histopathology.

UNASSIGNED: Robotic surgery (RS) has the advantages of 3-dimensional view, optical magnification, motional scaling, and improved ergonomics and degree of freedom. Although RS has widely been performed on pediatric patients lately, there are still numerous restrictions and ambiguous indications. The purpose of this study was to report our early experience with RS on pediatric patients at a single center.
UNASSIGNED: Electronic medical records of patients who underwent RS with the da Vinci Xi surgical platform (Intuitive Surgical, Inc.) in Seoul National University Children Hospital from November 2019 to August 2021 were reviewed retrospectively. The median follow-up was 21.0 months (range, 12.3-31.8 months). An online survey was conducted to investigate satisfaction with robotic surgical scars.
UNASSIGNED: Fifty-four patients underwent robotic surgeries (median age at operation, 11.1 years [range, 0.1-17.8 years]). In our hospital, patients had 20 different kinds of robotic surgeries, including choledochal cyst excision with hepaticojejunostomy, ovarian mass excision, and others. Median operation time and console time were 157.5 minutes (range, 45-505 minutes) and 40 minutes (range, 11-360 minutes), respectively. All cases were done without conversion into open or laparoscopic methods. Postoperative complications were found in 5 patients. According to an online survey, over half of patients (60.9%) answered that they felt satisfied with scars.
UNASSIGNED: Our early experience demonstrated the safety and feasibility of RS in children with a range of diagnoses and complicated procedures. With more experience, RS could be an alternative to traditional open or laparoscopic operations in pediatric patients. Further studies are needed to clarify indications of pediatric RS.

Giant choledochal cysts are rare, and so little data exist on the best surgical treatment method. We present here, a case of a giant choledochal cyst that was successfully excised by laparoscopic resection. A 37-year-old female presented with right upper abdominal pain and mild jaundice. On examination she had a right upper abdominal mass which on imaging was observed to be a giant choledochal cyst of type IVa, measuring approximately 129 mm × 190 mm. Her blood test results showed abnormal liver function. We successfully performed laparoscopic resection of the cyst, the patient recovered well and was discharged from hospital eight days post-operation without any complications. We wish to share the experience of this rare case and provide some clinical basis for future diagnosis and use of laparoscopic resection in the treatment of giant choledochal cysts.

OBJECTIVE: To analyze the ability of magnetic resonance (MR) to identify cystic biliary atresia (CBA) and choledochal cyst (CC).
METHODS: Infants (≤ 1 year old) who were diagnosed with CBA or CC type I/IV from January 2010 to July 2023 were retrospectively reviewed. Imaging characteristics on MR were compared between the CBA and CC groups. Binary logistic regression and the area under the receiver operating characteristic curve (AUC) were analyzed for the identification of CBA.
RESULTS: Sixty-three patients with CBA (median age, 30 days) and 172 patients with CC (median age, 60 days) were included. Gallbladder (GB) wall thickness (cutoff, 1.2 mm) showed 98.4% sensitivity and 100% specificity (AUC, 0.998). MR-triangular cord thickness (MR-TCT) (cutoff, 4.1 mm) showed 100% sensitivity and 95.9% specificity (AUC, 0.986). The bile duct loop visualization showed 96.8% sensitivity and 100% specificity (AUC, 0.984). Proximal bile duct (PBD) diameter (cutoff, 1.3 mm) showed 92.1% sensitivity and 95.3% specificity (AUC, 0.977). Cyst wall thickness (cutoff, 1 mm) showed 77.8% sensitivity and 95.3% specificity (AUC, 0.942). The combination of GB wall thickness > 1.2 mm and MR-TCT > 4.1 mm, GB wall thickness > 1.2 mm and loop visualization, GB wall thickness > 1.2 mm, and cyst wall thickness > 1 mm showed 100% sensitivity and 100% specificity (AUC, 1.000).
CONCLUSIONS: Imaging characteristics on MR might be used to identify CBA and CC, and the combination of GB wall thickness and MR-TCT, or loop visualization, or cyst wall thickness, has a perfect diagnostic value.
CONCLUSIONS: Early and accurate differentiation of CBA and CC is essential, but current methods rely on inherently subjective ultrasound. Biliary features on MRI allow for an objective, accurate diagnosis.

BACKGROUND: Choledochal cyst with perforation (CC with perforation) rarely occurs, early diagnosis and timely treatment plan are crucial for the treatment of CC with perforation. This study aims to forecast the occurrence of CC with perforation.
METHODS: All 1111 patients were conducted, who underwent surgery for choledochal cyst at our hospital from January 2011 to October 2022. We conducted univariate and multivariate logistic regression analysis to screen for independent predictive factors for predicting CC with perforation, upon which established a nomogram. The predictive performance of the nomogram was evaluated using receiver operating characteristic (ROC) curves, calibration plots, and decision curve analysis (DCA) curves.
RESULTS: The age of children with choledochal cyst perforation is mainly concentrated between 1 and 3 years old. Logistic regression analysis indicates that age, alanine aminotransferase, glutamyl transpeptidase, C-reactive protein, vomiting, jaundice, abdominal distension, and diarrhea are associated with predicting the occurrence of choledochal cyst perforation. ROC curves, calibration plots, and DCA curve analysis curves demonstrate that the nomogram has great discriminative ability and calibration, as well as significant clinical utility.
CONCLUSIONS: The age of CC with perforation is mainly concentrated between 1 and 3 years old. A nomogram for predicting the perforation of choledochal cyst was established.

BACKGROUND: Biliary intraepithelial neoplasia (BilIN), a noninvasive precursor of cholangiocarcinoma, can manifest malignant transformation. Since cholangiocarcinoma (CCA) may progress due to chronic inflammation in the bile ducts and gallbladder, choledochal cysts are considered a precursor to CCA. However, BilIN has rarely been reported in children, to date.
METHODS: We reviewed medical records of patients (< 18 years of age, n = 329) who underwent choledochal cyst excision at Asan Medical Center from 2008 to 2022. BilIN was diagnosed in 15 patients. Subsequent analyses were performed of the demographics, surgical procedures, clinical course, and outcomes in these patients. Subgroup analysis and multivariate logistic regression test were performed to identify factors influencing BilIN occurrence.
RESULTS: The mean age of the patients included in our study was 40.1 ± 47.6 months. In 15 patients, BilIN of various grades was diagnosed. Todani type I was prevalent in 80% of the patients. The median age at surgery was 17 months. During a mean follow-up of 63.3 ± 94.0 months, no adverse events such as stone formation in the remnant intrapancreatic common bile duct and intrahepatic duct or cholangiocarcinoma were observed, indicating a favorable outcome until now.
CONCLUSIONS: The potential progression of choledochal cysts to BilIN in children was demonstrated. These results could underscore the importance of early and comprehensive excision of choledochal cysts, including resection margins for associated lesions and more thorough postoperative surveillance in patients with or at risk of BilIN.

Laparoscopic and robotic surgery is a challenge to the surgeon\'s hand-eye coordination ability, which requires constant practice. Traditional mentor training is gradually shifting to simulation training based on various models. Laparoscopic and robotic bilioenteric anastomosis is an important and difficult operation in hepatobiliary surgery. We constructed and optimized the reusable modular 3D-printed models of choledochal cyst. The aim of this study was to verify the ability of this optimized model to distinguish between surgeons with different levels of proficiency and the benefits of repeated practice. A total of 12 surgeons with different levels participated in the study. Operation completion time and OSATS score were recorded. The model was validated by Likert scale. Surgeons were shown the steps and contents before performing laparoscopic or robotic bilioenteric anastomosis using the model. Surgeons with different levels of experience showed different levels when performing laparoscopic bilioenteric anastomosis on this model. Repeated training can significantly shorten the time of laparoscopic bilioenteric anastomosis and improve the operation scores of surgeons with different levels of experience. At the same time, preliminary results have shown that the performance of surgeons on the domestic robotic platform was basically consistent with their laparoscopic skills. This model may distinguish surgeons with different levels of experience and may improve surgical skills through repeated practice. It is worth noting that in order to draw more reliable conclusions, more subjects should be collected and more experiments should be done in the future.