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.

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.

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.

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.

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.

MRI-based decision tree model for diagnosis of biliary atresia.

OBJECTIVES: To evaluate MRI findings and to generate a decision tree model for diagnosis of biliary atresia (BA) in infants with jaundice. METHODS: We retrospectively reviewed features of MRI and ultrasonography (US) performed in infants with jaundice between January 2009 and June 2016 under approval of the institutional review board, including the maximum diameter of periportal signal change on MRI (MR triangular cord thickness, MR-TCT) or US (US-TCT), visibility of common bile duct (CBD) and abnormality of gallbladder (GB). Hepatic subcapsular flow was reviewed on Doppler US. We performed conditional inference tree analysis using MRI findings to generate a decision tree model. RESULTS: A total of 208 infants were included, 112 in the BA group and 96 in the non-BA group. Mean age at the time of MRI was 58.7 ± 36.6 days. Visibility of CBD, abnormality of GB and MR-TCT were good discriminators for the diagnosis of BA and the MRI-based decision tree using these findings with MR-TCT cut-off 5.1 mm showed 97.3 % sensitivity, 94.8 % specificity and 96.2 % accuracy. CONCLUSIONS: MRI-based decision tree model reliably differentiates BA in infants with jaundice. MRI can be an objective imaging modality for the diagnosis of BA. KEY POINTS: • MRI-based decision tree model reliably differentiates biliary atresia in neonatal cholestasis. • Common bile duct, gallbladder and periportal signal changes are the discriminators. • MRI has comparable performance to ultrasonography for diagnosis of biliary atresia.

Points to be considered when applying FibroScan S probe in children with biliary atresia.

OBJECTIVES: With the introduction of smaller probes (S1, S2), the use of transient elastography has been expanded to children. Accordingly, we aimed to address points of consideration in probe choice and interpretation of measured liver stiffness by applying and comparing FibroScan S and M probes in biliary atresia. METHODS: Using S1, S2, and M probes, 3 liver stiffness measurements, success rates, and interquartile ranges were obtained from 100 patients. Patients were assigned to 2 groups according to thoracic perimeter (≤ 45 cm vs > 45 cm). In both groups, obtained values were compared and the relation between liver stiffness measurement and aspartate aminotransferase-to-platelet ratio index was analyzed. RESULTS: In the small-thorax group, the success rate was highest with the S1 probe and the intraclass correlation coefficient (ICC) was highest for S1 versus S2 (0.98), compared with that for S1 versus M (0.69) and S2 versus M (0.77). In the large-thorax group, ICC was the highest for S2 versus M (0.88), compared with that for S1 versus S2 (0.69) and S1 versus M (0.51). In the small-thorax group, correlations between aspartate aminotransferase-to-platelet ratio index and liver stiffness measurement were stronger for S1 (0.65) and S2 (0.64) than for M (0.49). In the large-thorax group, all probes showed good correlation, S1 (0.68), S2 (0.62), and M (0.62). CONCLUSIONS: We recommend that the S1 probe is more appropriate for use in small children, especially those with a thorax perimeter of < 45 cm. If no S probe is available, the M probe may be acceptable in children whose thorax perimeter is > 45 cm.

Transient elastography and sonography for prediction of liver fibrosis in infants with biliary atresia.

OBJECTIVES: The purpose of this study was to assess the diagnostic performance of transient elastography and sonography for noninvasive evaluation of liver fibrosis in infants with biliary atresia. METHODS: Forty-seven infants with biliary atresia who underwent both transient elastography and sonography before surgery were included in this study. Two types of transient elastographic probes were used: an M probe, which is used for the general adult population; and an S probe, which is specific to children. Transient elastographic measurements and sonographic findings such as triangular cord thickness and hepatic artery and portal vein diameters were compared with the METAVIR histopathologic fibrosis scoring system. RESULTS: Only transient elastography (ρ = 0.63; P < .001) was significantly correlated with METAVIR fibrosis stages. The areas under the receiver operating characteristic curves for transient elastography were 0.86 and 0.96 for diagnosis of severe fibrosis and cirrhosis, respectively. The cutoff value of transient elastography for diagnosis of severe fibrosis was greater than 9.6 kPa, with sensitivity of 89.5% and specificity of 75%. The cutoff value of transient elastography for diagnosis of cirrhosis was greater than 18.1 kPa, with sensitivity of 100% and specificity of 90.5%. The success rate for the S probe (100%) was significantly higher than that for the M probe (77%; P < .001). CONCLUSIONS: Transient elastography may be a useful noninvasive method for diagnosis of severe fibrosis and cirrhosis and may help predict outcomes before surgery or invasive liver biopsy in infants with biliary atresia. The success rate of transient elastography in infants was improved by using the S probe.

Magnesium as an adjuvant for caudal analgesia in children.

BACKGROUND: There is a need for an adjuvant agent of caudal block that prolongs its duration and improves the analgesic efficacy to fasten functional recovery. Magnesium is an N-methyl-D-aspartate receptor antagonist that functions as an analgesic. This study was aimed to evaluate whether magnesium as an adjuvant for caudal block in children can improve postoperative analgesia and functional recovery. METHODS: Eighty children, 2-6 years of age, undergoing inguinal herniorrhaphy, were included in this prospective, randomized, double-blinded study. For caudal block, Group R received ropivacaine 1.5 mg·ml(-1), 1 ml·kg(-1) and Group RM received the same dose of ropivacaine mixed with 50 mg of magnesium. The Parents' Postoperative Pain Measure (PPPM) score, analgesic consumption, functional recovery, and adverse effects were evaluated at 6, 24, 48, and 72 h after surgery, as well as daily thereafter until the child showed full functional recovery. RESULTS: The PPPM score after hospital discharge was significantly lower for Group RM than for Group R at all times (P < 0.05). Children in Group RM required less fentanyl for rescue analgesia in the recovery area (16.2% vs 39.5%, P = 0.034) and less oral analgesics after discharge (20.5% vs 52.6%, P = 0.007). The time to return of normal functional activity was shorter in Group RM (P < 0.05). The incidence of adverse effects did not differ between groups. CONCLUSIONS: As an adjuvant for caudal analgesia, 50 mg magnesium provided superior quality of analgesia and faster return of normal functional activity than local anesthetic alone in children.

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.

Second serial transverse enteroplasty procedure in an infant with extreme short bowel syndrome.

The serial transverse enteroplasty (STEP) procedure is a novel technique to lengthen and taper the bowel in patients with short bowel syndrome. The advantages of STEP include not only technical ease and simplicity, but also the ability to repeat the procedure. Herein, we report a case of extreme short bowel syndrome that was successfully treated by the second STEP procedure. A 3-day old newborn girl underwent STEP because of jejunal atresia with the small bowel length of 15 cm, but her bowel elongation was not enough to escape from short bowel syndrome. At the age of 6 months, she underwent a second STEP procedure. The bowel lengthening by the second STEP made her tolerable to enteral feeding with body weight gain and rescued her from short bowel syndrome. This case showed that second STEP is very helpful in treatment of extreme short bowel syndrome.

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.

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.

Evaluation of liver fibrosis with T2 relaxation time in infants with cholestasis: comparison with normal controls.

BACKGROUND: The degree of hepatic fibrosis in biliary atresia (BA) correlates with the prognosis of the disease and thus, early diagnosis of liver fibrosis is clinically important. Liver biopsy is the gold standard for the evaluation of liver fibrosis, but it is an invasive procedure requiring sedation in children. Therefore, it is desirable to identify a noninvasive method for diagnosis and follow-up of hepatic fibrosis. OBJECTIVE: The purpose of this study is to evaluate the possibility of quantifying liver fibrosis in infants by T2 relaxation time measurements. MATERIALS AND METHODS: The institutional review board approved this prospective study and parental informed consent was obtained. During MR cholangiopancreatography using a 1.5-T MR scanner in infants with neonatal cholestasis, T2 relaxation time of the liver was calculated with the mean signal intensities measured on images obtained using spin-echo sequences (TR/TE, 2,000/20, 40, 60, 80, 100, 120, 140, 160 ms). A normal control study was performed during spinal MRI in infants with anorectal malformation and normal liver enzyme profiles. A liver biopsy was obtained in the children with cholestasis. The correlation between histopathological fibrosis stage and T2 relaxation time was evaluated by Kendall's Tau-b test. RESULTS: Twenty-five infants (male: female, 12:13; age range 0-11 months, mean 3.2 months), 14 with neonatal cholestasis (9 BA and 5 non-BA) and 11 normal controls were included in this study. Relaxation times (mean ± standard deviation [SD]) for the liver were 57.8 ms ± 8.8 in the normal control group (n=11) and 56.8 ms ± 9.6 in the BA group (n=9) without statistically significant differences (P=0.811). T2 relaxation times were not significantly different between the low stage (≤ F1) and high stage (≥ F2) fibrosis (mean 57.8 vs 56.8; P=0.934). CONCLUSION: T2 relaxation of a normal infant liver at 1.5-T had a mean value of 57.8 ms, which is comparable with adult data (46-57 ms). However, T2 relaxation time was not different in patients with BA and did not correlate with stage of fibrosis.

Gadopentetate dimeglumine-enhanced MR cholangiopancreatography in infants with cholestasis.

BACKGROUND: Biliary atresia (BA) is a progressive, obliterative cholangiopathy that occurs in neonates with hepatic portoenterostomy the treatment of choice, but early surgery is important for optimum outcomes. MRI, including MR cholangiopancreatography (MRCP) may be a diagnostically useful alternative to US, but the heavily T2-weighted sequences used include not only bile duct signals, but also other heterogeneously high signal intensities from surrounding structures. OBJECTIVE: To evaluate the effects of gadolinium when used to decrease background signal intensity on T2-weighted MR cholangiopancreatography (MRCP) in infants and to evaluate the qualitative improvement of the depiction of the common bile duct (CBD) for evaluating neonatal cholestasis. MATERIALS AND METHODS: Our Institutional Review Board approved this prospective study. MRCP was performed with gadopentetate dimeglumine injection using a 1.5-T scanner. Pre- and postcontrast MRCP images were compared. Forty-nine infants (male:female = 21:28; age 0-12 months, mean 2.3) were included. The final diagnoses were biliary atresia (BA) in 28 cases and non-BA in 21. Quantitative analysis was conducted using region-of-interest measurements of mean signal intensities of the liver, pancreatic head and gallbladder (if defined). Qualitative analysis was performed by four radiologists who subjectively scored image confidence in the presence of CBD on a 4-point scale (0 for definitely absent, 1 for probably absent, 2 for probably present, and 3 for definitely present). RESULTS: The signal-to-noise ratios were significantly decreased in the liver and pancreatic head after contrast medium enhancement (mean 5.7→4.0 in liver and mean 44.9→12.7 in the pancreatic head; P < 0.0001), and this finding was constant in both the BA and the non-BA group. The mean confidence score in the presence of CBD decreased in the BA group (0.9→0.5; P < 0.0001), but did not change significantly in the non-BA group (2.0→2.1; P = 0.459) after contrast medium enhancement. Both intra- and interobserver agreement was higher after contrast medium enhancement (P = 0.046). CONCLUSION: Gadopentetate dimeglumine-enhanced MRCP increased the diagnostic confidence of absence of the CBD in cholestatic infants with increased intra- and interobserver agreement.

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.

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.

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.