Optimal timing of surgery for prenatally diagnosed choledochal cysts.

Objective: Choledochal cysts are increasingly being diagnosed antenatally. The appropriate time of surgical treatment has the greatest impact on the prognosis of choledochal cyst treatment. The purpose of this study was to compare the clinical outcomes of prenatally diagnosed choledochal cysts in infants according to the surgical treatment timing. Methods: We retrospectively reviewed the medical records of infants who underwent surgery for choledochal cysts with antenatal diagnoses. We investigated each patient's demographic information, type of choledochal cyst, serum liver enzyme levels, and surgical outcomes according to the surgical intervention timing. Results: Between May 2006 and December 2020, 93 infants underwent surgery to treat choledochal cysts; among them, 68 had antenatally suspected choledochal cysts. Of the 68 patients, 21 developed symptoms directly after birth. While 38 patients remained asymptomatic, 9 developed symptoms before operation. To compare surgical outcomes, asymptomatic patients were divided into early (13 cases) and late (25 cases) operation groups based on an age benchmark of 30 days. The early surgical group experienced longer times to resume a full diet (6.0 ± 1.6 vs. 4.5 ± 0.7, p < 0.001) and longer postoperative hospital stays (11 ± 3.9 vs. 7.5 ± 0.8, p < 0.001). Surgical complications occurred in two patients in the early operation group. Minimally invasive surgery was performed in 12 patients in the late operation group. In both groups, postoperative liver function recovered at 6 months, with no significant difference. Conclusion: The results of this study showed longer hospital stays, increased diet durations, and postoperative complications in early surgery patients. However, liver function recovery was not different between the early and late operation groups. Thus, asymptomatic patients should be closely monitored, and we recommend that definitive surgical intervention be postponed until 4 months of age or until weight reaches 7 kg.

Pre- and Immediate Post-Kasai Portoenterostomy Shear Wave Elastography for Predicting Hepatic Fibrosis and Native Liver Outcomes in Patients With Biliary Atresia.

OBJECTIVE: To evaluate the feasibility of ultrasound shear wave elastography (SWE) for predicting hepatic fibrosis and native liver outcomes in patients with biliary atresia. MATERIALS AND METHODS: This prospective study included 33 consecutive patients with biliary atresia (median age, 8 weeks [interquartile range, 6-10 weeks]; male:female ratio, 15:18) from Severance Children's Hospital between May 2019 and February 2022. Preoperative (within 1 week from surgery) and immediate postoperative (on postoperative days [PODs] 3, 5, and 7) ultrasonographic findings were obtained and analyzed, including the SWE of the liver and spleen. Hepatic fibrosis, according to the METAVIR score at the time of Kasai portoenterostomy and native liver outcomes during postsurgical follow-up, were compared and correlated with imaging and laboratory findings. Poor outcomes were defined as intractable cholangitis or liver transplantation. The diagnostic performance of SWE in predicting METAVIR F3-F4 and poor hepatic outcomes was analyzed using receiver operating characteristic (ROC) analyses. RESULTS: All patients were analyzed without exclusion. Perioperative advanced hepatic fibrosis (F3-F4) was associated with older age and higher preoperative direct bilirubin and SWE values in the liver and spleen. Preoperative liver SWE showed a ROC area of 0.806 and 63.6% (7/11) sensitivity and 86.4% (19/22) specificity at a cutoff of 17.5 kPa for diagnosing F3-F4. The poor outcome group included five patients with intractable cholangitis and three undergoing liver transplantation who showed high postoperative liver SWE values. Liver SWE on PODs 3-7 showed ROC areas of 0.783-0.891 for predicting poor outcomes, and a cutoff value of 10.3 kPa for SWE on POD 3 had 100% (8/8) sensitivity and 73.9% (17/23) specificity. CONCLUSION: Preoperative liver SWE can predict advanced hepatic fibrosis, and immediate postoperative liver SWE can predict poor native liver outcomes in patients with biliary atresia.

Comparison of Surgical Outcomes of Laparoscopic Glue and Laparoscopic Suture Hernioplasty in Pediatric Female Inguinal Hernia.

This study aimed to report the surgical outcomes of laparoscopic glue hernioplasty (LGH) compared with conventional laparoscopic suture hernioplasty (LSH) in pediatric female inguinal hernia repair. We retrospectively analyzed 465 female pediatric patients who underwent laparoscopic inguinal hernia repair between January 2013 and December 2020. LGH and LSH were performed in 95 and 370 cases, respectively. Surgical outcomes (length of hospital stay, operative time, complications, and recurrences) were compared between the LGH and LSH groups. We found that the operation times for bilateral hernia repair were shorter in the LGH group (LGH: 35.5 ± 8.2 min, LSH: 45.2 ± 11.6 min; p < 0.001). No significant differences in complications or recurrences were observed between the two groups during the follow-up period. Our findings suggest that LGH is a feasible and easily applied surgical technique for the treatment of pediatric female inguinal hernia.

Changes in outcomes and operative trends with pediatric robot-assisted resection of choledochal cyst.

BACKGROUND: This study aimed to report our experience with a robot-assisted resection of choledochal cysts (CCs) in pediatric patients, especially focusing on changes in outcomes and operative trends. METHODS: We retrospectively reviewed medical records of all 158 patients under 18 years of age who underwent robot-assisted resection of CC in a single tertiary center between July 2008 and January 2021. Patients were divided into the first period (P1, July 2008-March 2016; N = 79) and second period (P2, April 2016-January 2021; N = 79) with equal number of participants. The patients of P2 were compared with those of P1 to assess clinical outcomes with operative details. Operative characteristics and postoperative prognosis were compared for each group. RESULTS: The mean operative time was 383.6 min for the P2 group and 462.6 min for the P1 group (p < 0.001). The mean estimated blood loss was 28 mL in the P2 group and 63 mL in the P1 group (p = 0.025). The rate of emergency department visit after the operation was lower in the P2 group (3.8% vs. 13.9%, respectively, p = 0.047). The two groups showed no significant differences in the rate of late postoperative complications and reoperations. CONCLUSION: With the increase in the center's experience, robot-assisted resection of CC can be safely adopted and feasible, especially for pediatric patients. LEVELS OF EVIDENCE: Treatment Study, Level III.

Long-term usage pattern and satisfaction survey of continent catheterizable channels.

INTRODUCTION: We investigated the long-term usage pattern and satisfaction of continent catheterizable channels (CCCs). METHODS: From 2005 to 2018, CCCs, including Mitrofanoff and antegrade continent enema (ACE) channels, were made in 67 patients (Mitrofanoff in 21 patients, ACE channels in 43 patients, and both in three patients) in our institution. An online survey was conducted for these patients in order to assess usage pattern, continent status, difficulty in usage, and patient satisfaction. RESULTS: Sixteen (66.7%) out of 24 patients with the Mitrofanoff channel and 39 (84.7%) out of 46 patients with the ACE channel completed the online survey. In the Mitrofanoff channel group, 10 (62.5%) patients had spina bifida, two (12.5%) had Hinman syndrome, one (6.3%) had posterior urethral valves, and three (18.8%) had urethral trauma or atresia. Additionally, the mean age of the patients at the time of surgery was 10.0 years, and the median follow-up duration was 10.9 years. All patients were using the Mitrofanoff channel to perform clean intermittent catheterization (CIC). Eleven patients (68.8%) had difficulty with catheterization, mostly at the stomal site. Most patients conducted CIC more than four times a day (13, 81.3%). Regarding urination status, seven patients (43.8%) responded that they were satisfied and nine (56.2%) responded they were neutral. In the ACE channel group, 35 patients (89.7%) had spina bifida, seven (17.9%) had cloacal anomalies, and 26 (66.7%) had anorectal malformations. The mean age of the patients at the time of surgery was 8.4 years, and the median follow-up period was 7.4 years. Two (5.1%) patients were no longer using their ACE channels, but 15 (38.5%) patients were still using their channels almost daily. Twenty-eight (71.8%) patients complained that performing enema was time-consuming, and seven (17.9%) patients reported pain when performing ACE and fecal incontinence. Most patients were satisfied with their defecation status (23, 59%), 15 (38.5%) were neutral, and one (2.6%) was dissatisfied. CONCLUSIONS: While most patients who had either Mitrofanoff or ACE channels were still using their channels effectively, approximately half of the patients with CCCs demonstrated neutral satisfaction with their current status; this shows a poor result compared to previous reports. Considering the results of our patient-based study, thorough explanations should be provided to patients who are candidates for Mitrofanoff and ACE procedures; additionally, the discomfort related to the procedures should be comprehensively assessed during follow-up consults.

Effect of different driver power amplitudes on liver stiffness measurement in pediatric liver MR elastography.

PURPOSE: To assess how different driver power amplitudes affect the measurement of liver stiffness in pediatric liver magnetic resonance elastography (MRE). METHODS: From January 2018 to May 2018, pediatric patients (≤ 18 years) who underwent liver MRE with 20% and 56% driver power amplitudes were included in this retrospective study. Region-of-interests (ROIs) were drawn on four stiffness maps to include the largest area of the liver parenchyma. Intraclass correlation coefficients (ICCs) were used to assess agreements for the area, mean, maximum, minimum and standard deviation of liver stiffness between the driver power amplitudes. RESULTS: 128 MRE stiffness maps from 16 patients (M:F = 10:6, median 12.5 years old) were included. On MRE, median ROI areas of liver were 83.1 cm2 (range, 46.9-144.1 cm2) and 63.0 cm2 (range, 5.4-123.4 cm2) for the driver power amplitudes of 20% and 56%, respectively. Median liver stiffness values were 2.3 kPa (range, 1.7-8.0 kPa) and 2.8 kPa (range, 1.7-8.5 kPa). Maximum and minimum liver stiffness values were 5.3 kPa and 1.0 kPa for 20% and 7.8 kPa and 1.1 kPa for 56%. Standard deviation was 0.6 kPa for 20% and 1.0 kPa for 56%. ICC values between the two power amplitudes were 0.33-0.51 for the ROI area and the maximum, minimum and standard deviation values of liver stiffness. The ICC value for liver stiffness was 0.857 (95% confidence interval, 0.760-0.915). CONCLUSION: Liver stiffness with two driver power amplitudes on MRE showed good reliability in pediatric patients. Driver power amplitudes need to be optimized according to the pediatric liver size.

Quantitative MRI Assessment of Pancreatic Steatosis Using Proton Density Fat Fraction in Pediatric Obesity.

OBJECTIVE: To assess the feasibility of quantitatively assessing pancreatic steatosis using magnetic resonance imaging (MRI) and its correlation with obesity and metabolic risk factors in pediatric patients. MATERIALS AND METHODS: Pediatric patients (≤ 18 years) who underwent liver fat quantification MRI between January 2016 and June 2019 were retrospectively included and divided into the obesity and control groups. Pancreatic proton density fat fraction (P-PDFF) was measured as the average value for three circular regions of interest (ROIs) drawn in the pancreatic head, body, and tail. Age, weight, laboratory results, and mean liver MRI values including liver PDFF (L-PDFF), stiffness on MR elastography, and T2* values were assessed for their correlation with P-PDFF using linear regression analysis. The associations between P-PDFF and metabolic risk factors, including obesity, hypertension, diabetes mellitus (DM), and dyslipidemia, were assessed using logistic regression analysis. RESULTS: A total of 172 patients (male:female = 125:47; mean ± standard deviation [SD], 13.2 ± 3.1 years) were included. The mean P-PDFF was significantly higher in the obesity group than in the control group (mean ± SD, 4.2 ± 2.5% vs. 3.4 ± 2.4%; p = 0.037). L-PDFF and liver stiffness values showed no significant correlation with P-PDFF (p = 0.235 and p = 0.567, respectively). P-PDFF was significantly associated with obesity (odds ratio 1.146, 95% confidence interval 1.006-1.307, p = 0.041), but there was no significant association with hypertension, DM, and dyslipidemia. CONCLUSION: MRI can be used to quantitatively measure pancreatic steatosis in children. P-PDFF is significantly associated with obesity in pediatric patients.

Validating the BAVENO VI criteria to identify low risk biliary atresia patients without endoscopy for esophageal varix.

BACKGROUND AND AIMS: Portoenterostomy is the initial surgical treatment for biliary atresia (BA); however, no curative therapy exists for BA. Varix bleeding is a major complication of end-stage liver disease and must be determined in patients with BA, necessitating routine surveillance using esophagogastroduodenoscopy (EGD). We attempted to validate criteria to identify BA patients requiring EGD. METHODS: From January 2007 to December 2017, we selected BA patients who underwent Kasai surgery, transient elastography (TE), and EGD at Severance hospital. In total, 190 cases were included; laboratory tests and EGDs were carried out from 3 months before TE to 3 months after TE. RESULTS: Based on the cut-off value (<10) of the liver stiffness measurement (LSM), 35 (81.4%) patients with low-risk varix (LRV) and 8 (18.6%) with high-risk varix (HRV) were identified. Based on platelet counts (>150,000), 87 (77.68%) patients with LRV and 25 (22.32%) with HRV were identified. Based on this, the BAVENO VI criteria, which identify patients who can safely avoid screening EGD, missed 9/68 (13.24%) of HRV patients. The expanded BAVENO VI criteria missed 21/68 (30.88%) of HRV patients. However, the criteria using LSM <10 and platelet count >150,000 missed identifying only 4/68 (5.88%) HRV patients. CONCLUSIONS: The BAVENO criteria may be as useful in children with BA as in adults with liver cirrhosis. Regular laboratory tests, imaging studies, and EGD may avoid missing diagnoses of varices in BA patients. However, LSM<10 and platelet count>150,000 may provide more accurate criteria and help identify patients who does not need endoscopy.

Diffusion-Weighted Imaging for Differentiation of Biliary Atresia and Grading of Hepatic Fibrosis in Infants with Cholestasis.

OBJECTIVE: To determine whether the values of hepatic apparent diffusion coefficient (ADC) can differentiate biliary atresia (BA) from non-BA or be correlated with the grade of hepatic fibrosis in infants with cholestasis. MATERIALS AND METHODS: This retrospective cohort study included infants who received liver MRI examinations to evaluate cholestasis from July 2009 to October 2017. Liver ADC, ADC ratio of liver/spleen, aspartate aminotransferase to platelet ratio index (APRI), and spleen size were compared between the BA and non-BA groups. The diagnostic performances of all parameters for significant fibrosis (F3-4) were obtained by receiver-operating characteristics (ROCs) curve analysis. RESULTS: Altogether, 227 infants (98 males and 129 females, mean age = 57.2 ± 36.3 days) including 125 BA patients were analyzed. The absolute ADC difference between two reviewers was 0.10 mm²/s for both liver and spleen. Liver ADC value was specific (80.4%) and ADC ratio was sensitive (88.0%) for the diagnosis of BA with comparable performance. There were 33 patients with F0, 15 with F1, 71 with F2, 35 with F3, and 11 with F4. All four parameters of APRI (τ= 0.296), spleen size (τ= 0.312), liver ADC (τ= -0.206), and ADC ratio (τ= -0.288) showed significant correlation with fibrosis grade (all, p < 0.001). The cutoff values for significant fibrosis (F3-4) were 0.783 for APRI (area under the ROC curve [AUC], 0.721), 5.9 cm for spleen size (AUC, 0.719), 1.044 × 10-3 mm²/s for liver ADC (AUC, 0.673), and 1.22 for ADC ratio (AUC, 0.651). CONCLUSION: Liver ADC values and ADC ratio of liver/spleen showed limited additional diagnostic performance for differentiating BA from non-BA and predicting significant hepatic fibrosis in infants with cholestasis.

Key imaging features for differentiating cystic biliary atresia from choledochal cyst: prenatal ultrasonography and postnatal ultrasonography and MRI.

PURPOSE: This study compared clinical and radiologic differences between cystic biliary atresia (cBA) and choledochal cyst (CC) type Ia/b. METHODS: Infants (≤12 months old) who were diagnosed with cBA or CC type Ia/b from 2005 to 2019 were retrospectively reviewed. Imaging features on preoperative ultrasonography (US) and magnetic resonance imaging (MRI) were compared between the cBA and CC groups. Logistic regression and area under the receiver operating characteristic curve (AUC) analyses were performed for the diagnosis of cBA. Changes in cyst size were also evaluated when prenatal US exams were available. RESULTS: Ten patients (5.5% of biliary atresia cases) with cBA (median age, 48 days) and 11 infants with CC type Ia/b (Ia:Ib=10:1; median age, 20 days) were included. Triangular cord thickness on US (cutoff, 4 mm) showed 100% sensitivity and 90.9% specificity (AUC, 0.964; 95% confidence interval [CI], 0.779 to 1.000) and cyst size on MRI (cutoff, 2.2 cm) had 70% sensitivity and 100% specificity (AUC, 0.900; 95% CI, 0.690 to 0.987) for diagnosing cBA. Gallbladder mucosal irregularity on US and an invisible distal common bile duct on MRI were only seen in the cBA group (10 of 10). Only the CC group showed prenatal cysts exceeding 1 cm with postnatal enlargement. CONCLUSION: Small cyst size (<1 cm) on prenatal US, triangular cord thickening (≥4 mm) and gallbladder mucosal irregularity on postnatal US, and small cyst size (≤2.2 cm) and an invisible distal common bile duct on MRI can discriminate cBA from CC type Ia/b in infancy.

Periportal thickening on magnetic resonance imaging for hepatic fibrosis in infantile cholestasis.

BACKGROUND: Untreated neonatal cholestasis can progress to liver cirrhosis and end stage liver disease in infancy due to prolonged hepatocyte and biliary tree injury and may require liver transplantation. Therefore, non-invasive evaluation of hepatic fibrosis is important in infants with cholestasis. AIM: To investigate the usefulness of periportal thickening (PT) measured on liver magnetic resonance imaging (MRI) for the assessment of hepatic fibrosis in infants with cholestasis including biliary atresia (BA). METHODS: This retrospective study included infants less than 6 mo who underwent liver MRI and biopsy for the evaluation of infantile cholestasis. PT and spleen size were measured on MRI. Serologic assessment was based on aspartate transaminase to platelet ratio index (APRI). The grade of histopathologic fibrosis was assessed by the METAVIR grading system. Correlation and diagnostic performance of PT, normalized spleen size ratio (SR, using the upper normal size limit), and APRI for diagnosing hepatic fibrosis were obtained by receiver-operating characteristic (ROC) curve analysis. RESULTS: A total of 155 patients were included, 110 of which were diagnosed with BA. Mean age at the time of MRI was 57.6 ± 34.4 d. There were positive correlations between fibrosis grade and PT and SR, even after adjusting age (all, P < 0.001). For the diagnosis of significant fibrosis (METAVIR grade F2-F4), the area under the ROC curve was 0.899 (95%CI: 0.840-0.941) for PT (cutoff, 4.2 mm), which was higher than 0.741 (95%CI: 0.664-0.808) for SR and 0.712 (95%CI: 0.634-0.782) for APRI (both, P < 0.001). For the diagnosis of cirrhosis (F4), the area under the ROC curve was the highest with SR as 0.790 (95%CI: 0.718-0.852). CONCLUSION: Liver MRI findings of PT and SR are useful to assess clinically significant hepatic fibrosis (F2 and higher) in infants with cholestasis including BA.

Incidence and Risk Factors of Acute Kidney Injury after Kasai Operation for Biliary Atresia: A Retrospective Study.

Background: Biliary atresia is a progressive, inflammatory, and destructive pathology of the bile ducts. Patients who undergo surgery for correction of biliary atresia (Kasai operation) are at risk of acute kidney injury (AKI) because of their young age at the time of surgery, long operation time, and liver fibrosis or failure as complication of biliary atresia. Conversely, AKI is associated with poor outcomes after surgery. This study therefore aimed to evaluate the incidence, risk factors, and outcomes of AKI after Kasai operation. Methods: All consecutive patients who underwent Kasai operation between March 2006 and December 2015 in a single tertiary-care university hospital were enrolled. AKI was defined based on the Acute Kidney Injury Network criteria. Multivariate logistic regression models were used to assess risk factors for AKI. Results: One hundred sixty-six patients received Kasai operation during study period. Of these, AKI occurred in 37 of 166 patients (22.3%). In multivariate logistic regression analysis, age older than 30 days, higher preoperative estimated glomerular filtration rate, and preoperative contrast use within 7 days were associated with the development of AKI. Perioperative packed red blood cells transfusion was related to reduced occurrence of AKI. AKI was associated with longer ICU stay (OR = 1.015, p = 0.016). More patients with AKI were also found to receive additional surgery except liver transplantation within 1 year compared to those without AKI (10.8 % vs. 2.3 %, p = 0.045). Conclusions: Increased age is strongly associated with the development of AKI after Kasai operation. These findings indicate a rational basis for early corrective surgery for biliary atresia, early screening for AKI, and intervention to improve the results of Kasai operation.

Comparison of the outcomes of biliary atresia with cystic degeneration and isolated biliary atresia: A matched-pair analysis.

BACKGROUND: Patients with biliary atresia (BA) with extrahepatic cystic degeneration (BACD) have a unique pathophysiology; however, clinical outcomes and progression of perinatal degeneration are not well-defined. We aimed to investigate the differences in clinical characteristics and outcomes between BACD and isolated BA (IBA). METHODS: We performed a retrospective analysis of patients with BA who underwent Kasai portoenterostomy (KPE) from August 1997 to January 2018 and compared the clinical features and outcomes between BACD (n = 21) and IBA (n = 237). Matched-pair analysis for age and sex was performed between BACD and IBA groups to reduce confounding. RESULTS: Before matched-pair analysis, we found that BACD patients were younger at KPE (45 vs. 64 days, p = 0.008), showed lower total bilirubin at the 3-month follow-up (0.5 vs. 1.4 mg/dL, p = 0.002), and higher 5-year native liver survival rate (95.2% vs. 61.4%, p = 0.006) than IBA patients. After matching, the BACD group showed significantly lower total bilirubin levels at the 3-month follow-up (0.5 vs. 1.5 mg/dL, p = 0.036) and higher 5-year native liver survival rate (95.2% vs. 57.5%, p = 0.006) than the IBA group. CONCLUSION: BACD demonstrated higher bilirubin clearance and native liver survival rates than IBA. LEVELS OF EVIDENCE: Treatment Study, Level III.

Hepatic subcapsular or capsular flow in biliary atresia: is it useful imaging feature after the Kasai operation?

OBJECTIVES: To evaluate the implications of hepatic subcapsular and capsular flows using ultrasonography (US) in children after Kasai operation. METHODS: Children who underwent liver US including color Doppler US and microvascular imaging (MVI) from May 2017 to October 2017 were retrospectively included. Children who underwent the Kasai operation for biliary atresia were included in the Kasai group and children with normal liver were included in the control group. Using US results, the number of intrahepatic biliary cysts and the maximum diameter of the spleen were evaluated in the Kasai group. Liver stiffness values were included when patients in the Kasai group had transient elastography (TE) or shear wave elastography (SWE) results. Hepatic subcapsular and capsular flows on color Doppler US and MVI were compared between the two groups using the following scores: 0, no flow reaching the hepatic capsule; 1, any flow reaching the hepatic capsule; and 2, contiguous hepatic capsular flow. The logistic regression test was used to identify associations between age, intrahepatic biliary cysts, spleen size, SWV, TE results, and flow scores measured on Doppler US and MVI in the Kasai group using the odds ratio (OR) and 95% confidence interval (CI). RESULT: A total of 65 children (mean 7.6 ± 5.3 years), 44 in the Kasai group and 21 in the control group, were included. In the control group, one child had score 1 on MVI and others had score 0 on both Doppler US and MVI. Among the Kasai group, 28 children (63.6%) had score 1, while others had score 0 using Doppler US. Using MVI, 24 children (54.5%) had score 2, 18 children had score 1, and one child had score 0. In the Kasai group, increased liver stiffness on TE was the only factor significantly associated with the presence of subcapsular flow on color Doppler US (OR 1.225, 95% CI 1.020-1.470) and increased spleen size was the only factor significantly associated with increased flow scores on MVI (OR 1.397, 95% CI 1.002-2.724). CONCLUSION: Detection of hepatic subcapsular, capsular flows on US would be meaningful for children after receiving the Kasai operation. KEY POINTS: • Hepatic subcapsular or capsular flows can be useful not only for the diagnosis but also for the postoperative follow-up in patients with biliary atresia. • Increased liver stiffness and splenomegaly after the Kasai operation were associated with presence of subcapsular or capsular flow on ultrasonography. • Evaluation of hepatic subcapsular and capsular flows could be needed to assess disease progression after receiving the Kasai operation.

The Epidemiology and Etiology of Cholangitis After Kasai Portoenterostomy in Patients With Biliary Atresia.

OBJECTIVES: We investigated the incidence and characteristics of cholangitis after Kasai portoenterostomy (KPE) in patients with biliary atresia. We also examined the distribution and antimicrobial susceptibility patterns of the causative pathogens, which were isolated in sterile specimens, such as blood and ascites. METHODS: A retrospective chart review was performed in patients with biliary atresia who underwent KPE at Severance Children's Hospital in Korea from 2006 to 2015. The Kaplan-Meier method was used to assess the cumulative incidence of cholangitis. RESULTS: Among the 160 included patients, there were 494 episodes of cholangitis in 126 patients (78.8%) during the study period. The cumulative incidence of cholangitis at 1 and 5 years after KPE was 75.5% and 84.2%, respectively, and cholangitis recurred in most cases (76.2%). The cumulative incidence of culture-proven cholangitis at 1 and 5 years after KPE was 22.1% and 23.9%, respectively. Enterococcus faecium (27.7%) was the most prevalent pathogen, followed by Escherichia coli (14.9%), Enterobacter cloacae (10.6%), and Klebsiella pneumoniae (8.5%). Gram-positive isolates (n = 19) showed low susceptibility to ampicillin (42.1%) and gentamicin (66.7%), and only 38.1% of Gram-negative isolates (n = 21) were susceptible to cefotaxime. CONCLUSIONS: The present study is the largest to show the high incidence and characteristics of cholangitis after KPE in patients with biliary atresia. Enterococcus is a common pathogen of cholangitis after KPE and should be considered when choosing empiric antimicrobial therapy.

Clinical utility of mono-exponential model diffusion weighted imaging using two b-values compared to the bi- or stretched exponential model for the diagnosis of biliary atresia in infant liver MRI.

PURPOSE: To investigate the clinical utility of mono-exponential model diffusion weighted imaging (DWI) using two b-values compared to the bi- or stretched exponential model to differentiate biliary atresia (BA) from non-BA in pediatric liver magnetic resonance imaging (MRI). METHODS: Patients who underwent liver MRI with DWI for suspected BA from November 2017 to September 2018 were retrospectively included and divided into BA and non-BA groups. Laboratory results including γ-glutamyl transferase (γGT) were compared between the two groups using the Mann-Whitney U test and Fisher's exact test. The hepatic apparent diffusion coefficient (ADC) 10 using ten b-values and ADC 2 using two b-values were obtained from the mono-exponential model. The slow diffusion coefficient (D), fast diffusion coefficient (D*), and perfusion fraction (f) were obtained from the bi-exponential model. The distributed diffusion coefficient (DDC) and heterogeneity index (α) were measured from the stretched exponential model. Parameters were compared between the two groups using a linear mixed model and diagnostic performance was assessed using the area under the curve (AUC) analysis. RESULTS: For 12 patients in the BA and five patients in the non-BA group, the ADC 10 (median 0.985 ×10-3 mm2/s vs. 1.332 ×10-3 mm2/s, p = 0.008), ADC 2 (median 0.987 ×10-3 mm2/s vs. 1.335 ×10-3 mm2/s, p = 0.017), D* (median 33.2 ×10-3 mm2/s vs. 55.3 ×10-3 mm2/s, p = 0.021), f (median 13.4%, vs. 22.1%, p = 0.009), and DDC (median 0.889 ×10-3 mm2/s vs. 1.323 ×10-3 mm2/s, p = 0.009) values were lower and the γGT (median 368.0 IU/L vs. 93.5 IU/L, p = 0.02) and α (median 0.699 vs. 0.556, p = 0.023) values were higher in the BA group. The AUC values for γGT (AUC 0.867 95% confidence interval [CI] 0.616-0.984), ADC 10 (AUC 0.963, 95% CI 0.834-0.998), ADC 2 (AUC 0.925, 95% CI 0.781-0.987), f (AUC 0.850, 95% CI 0.686-0.949), and DDC (AUC 0.925, 95% CI 0.781-0.987) were not significantly different, except for the D* and α values. CONCLUSION: Patients with BA had lower ADC 10, ADC 2, D*, f, and DDC values and higher γGT and α values than those in the non-BA group. The diagnostic performance of ADC 2 using only two b-values showed excellent diagnostic performance and was not significantly different from that of γGT, ADC 10, f, and DDC for diagnosing BA.

Predicting variceal bleeding in patients with biliary atresia.

Background/aims: Variceal bleeding is the main cause of morbidity and mortality in children with portal hypertension and biliary atresia. The aim of this study is to predict high-risk varices by analyzing various clinical factors, thus improve prognosis of patients with biliary atresia.Methods: A total of 157 patients with biliary atresia who underwent Kasai portoentrostomy were enrolled in a single center. Clinical data including laboratory values, endoscopic findings and values of transient elastography (FibroScan®) were analyzed retrospectively.Results: The bleeding group and the non-bleeding group showed statistically significant differences in several variables; The FibroScan® value (HR 1.05, 95% CI (1.03-1.07), p < .01) was higher in the bleeding group. The bleeding group had values of lower albumin after 3 months of operation (HR 0.28, 95% CI (0.11-0.73), p = .01), higher bilirubin after 3 months of operation (total bilirubin: HR 1.18, 95% CI (1.04-1.33), p = .01), (direct bilirubin: HR 1.21, 95% CI (1.05-1.41), p = .01). Gastric varix (HR 4.10, 95% CI (1.62-10.36), p < .01) was more frequent in the bleeding group. And the presence of red sign was also predictive of bleeding. The FibroScan® cut-off value with the predictive power of bleeding was 31.5 kPa (HR 7.7, 95% CI (3.36-17.73), p < .01).Conclusions: Several clinical factors including high value of transient elastography (FibroScan®), gastric varix or red sign of endoscopy, and low albumin or high bilirubin values after 3 months of Kasai operation can be useful in predicting variceal bleeding in patients with biliary atresia.

Predicting gastroesophageal varices through spleen magnetic resonance elastography in pediatric liver fibrosis.

BACKGROUND: A recent retrospective study confirmed that hepatic stiffness and splenic stiffness measured with magnetic resonance elastography (MRE) are strongly associated with the presence of esophageal varices. In addition, strong correlations have been reported between splenic stiffness values measured with MRE and hepatic venous pressure gradients in animal models. However, most studies have been conducted on adult populations, and previous pediatric MRE studies have only demonstrated the feasibility of MRE in pediatric populations, while the actual clinical application of spleen MRE has been limited. AIM: To assess the utility of splenic stiffness measurements by MRE to predict gastroesophageal varices in children. METHODS: We retrospectively reviewed abdominal MRE images taken on a 3T system in pediatric patients. Patients who had undergone Kasai operations for biliary atresia were selected for the Kasai group, and patients with normal livers and spleens were selected for the control group. Two-dimensional spin-echo echo-planar MRE acquisition centered on the liver, with a pneumatic driver at 60 Hz and a low amplitude, was performed to obtain hepatic and splenic stiffness values. Laboratory results for aspartate aminotransferase to platelet ratio index (APRI) were evaluated within six months of MRE, and the normalized spleen size ratio was determined with the upper normal size limit. All Kasai group patients underwent gastroesophageal endoscopy during routine follow-up. The Mann-Whitney U test, Kendall's tau b correlation and diagnostic performance analysis using the area under the curve (AUC) were performed for statistical analysis. RESULTS: The median spleen MRE value was 5.5 kPa in the control group (n = 9, age 9-18 years, range 4.7-6.4 kPa) and 8.6 kPa in the Kasai group (n = 22, age 4-18 years, range 5.0-17.8 kPa). In the Kasai group, the APRI, spleen size ratio and spleen MRE values were higher in patients with portal hypertension (n = 11) than in patients without (n = 11) (all P < 0.001) and in patients with gastroesophageal varices (n = 6) than in patients without (n = 16) (all P < 0.05), even though their liver MRE values were not different. The APRI (τ = 0.477, P = 0.007), spleen size ratio (τ = 0.401, P = 0.024) and spleen MRE values (τ = 0.426, P = 0.016) also correlated with varices grades. The AUC in predicting gastroesophageal varices was 0.844 at a cut-off of 0.65 (100% sensitivity and 75% specificity) for the APRI, and 0.844 at a cut-off of 9.9 kPa (83.3% sensitivity and 81.3% specificity) for spleen MRE values. CONCLUSION: At a cut-off of 9.9 kPa, spleen MRE values predicted gastroesophageal varices as well as the APRI and spleen size ratio in biliary atresia patients after the Kasai operation. However, liver MRE values were not useful for this purpose.

A periodic comparison of the survival and prognostic factors of biliary atresia after Kasai portoenterostomy: a single-center study in Korea.

PURPOSE: We explored the chronologic changes in prognostic factors and clinical outcomes of Kasai portoenterostomy (KPE) for biliary atresia (BA). METHODS: Patients undergoing KPE between 1997 and 2016 were analyzed retrospectively. Ninety-two consecutive patients who underwent KPE from 1997 to 2006 (Era 1) were compared with 150 patients who underwent KPE from 2007 to 2016 (Era 2) for clinical outcomes and prognostic factors. RESULTS: The jaundice clearance rate increased by 8.8% (66.7% vs. 75.5% for Eras 1 and 2, respectively, p = 0.180), and the 5-year native liver survival (NLS) rate improved slightly (62.5% vs. 64.0% for Eras 1 and 2, respectively, p = 0.617) in Era 2. The hazard ratio for age at KPE (≥ 90 days) with regard to 5-year NLS and the odds ratio for age at KPE (< 90 days) with regard to jaundice clearance were both lower in Era 2 than in Era 1 (1.95 vs. 2.25 and 2.67 vs. 5.21, respectively). CONCLUSION: The clinical outcomes improved over a period in a single surgeon's practice. We demonstrated that the impact of age at the time of KPE on operative outcomes became less significant over time with the increase in the single surgeon's experience and improvement in medical treatment for BA.

Liver intravoxel incoherent motion diffusion-weighted imaging for the assessment of hepatic steatosis and fibrosis in children.

AIM: To evaluate the correlation between intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) parameters and the degree of hepatic steatosis and fibrosis in children. METHODS: This retrospective study was approved by the institutional review board. The children (≤ 18 years) who underwent liver IVIM DWI with 8 b-values under the suspicion of hepatic steatosis or fibrosis from February 2013 to November 2016 were included. Subjects were divided into normal, fatty liver (FAT), and fibrotic liver (FIB) groups. The slow diffusion coefficient (D), fast diffusion coefficient (D*), perfusion fraction (f), and apparent diffusion coefficient (ADC) were measured. MR proton density fat fraction (PDFF), MR elastography (MRE), and IVIM values were compared. RESULTS: A total of 123 children (median age of 12 years old, range: 6-18 years) were included, with 8 in the normal group, 93 in the FAT group, and 22 in the FIB group. The D* values were lower in the FIB group compared with those of the normal (P = 0.015) and FAT (P = 0.003) groups. The f values were lower in the FIB group compared with the FAT group (P = 0.001). In multivariate analyses, PDFF value was positively correlated with f value (ß = 3.194, P < 0.001), and MRE value was negatively correlated with D* value (ß = -7.031, P = 0.032). The D and ADC values were not influenced by PDFF or MRE value. CONCLUSION: In liver IVIM DWI with multiple b-values in children, there was a positive correlation between hepatic fat and blood volume, and a negative correlation between hepatic stiffness and endovascular blood flow velocity, while diffusion-related parameters were not affected.