The accuracy of magnetic resonance cholangiopancreatography in the diagnosis of biliary atresia in preterm infants with cholestasis

BACKGROUND

Magnetic resonance cholangiopancreatography (MRCP) is a useful and non-invasive method to diagnose biliary atresia (BA) in term infants, however few studies have investigated its use in preterm infants. This study aimed to evaluate the accuracy of MRCP in the diagnosis of BA in preterm infants with cholestasis.

METHODS

Infants aged less than 6 months who received MRCP for cholestasis at a tertiary medical center were enrolled from 2011 to 2020. Demographic and laboratory data were retrospectively obtained. One pediatric radiologist reviewed the MRCP images. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of MRCP to diagnose BA based on surgical proof or at least 6 months of follow-up were assessed.

RESULTS

A total of 80 infants (36 preterm and 44 term) were analyzed. The mean post-chronological age was 1.8 months, and the female-to-male ratio was 0.78. Six (16.7%) preterm and 16 (36.4%) term infants were confirmed to have BA. BA was obscured by a choledochal cyst preoperatively in two term infants. In the preterm infants, the sensitivity, specificity, PPV, NPV, and accuracy of MRCP to diagnose BA were 100%, 77%, 46%, 100%, and 81%, respectively, compared to 81%, 86%, 76%, 89%, and 84% in the term infants. Using MRCP to differentiate BA from other cholestasis in the preterm infants had superior sensitivity (100% vs. 81%) and NPV (100% vs. 89%), and lower specificity (77% vs. 86%) and PPV (46% vs. 76%) than in the term infants.

CONCLUSIONS

Negative MRCP findings can be used to exclude BA in preterm infants with cholestasis based on a favorable NPV.

Update on Etiology and Pathogenesis of Biliary Atresia

Biliary atresia is a rare inflammatory sclerosing obstructive cholangiopathy that initiates in infancy as complete choledochal blockage and progresses to the involvement of intrahepatic biliary epithelium. Growing evidence shows that biliary atresia is not a single entity with a single etiology but a phenotype resulting from multifactorial events whose common path is obliterative cholangiopathy. The etiology of biliary atresia has been explained as resulting from genetic variants, toxins, viral infection, chronic inflammation or bile duct lesions mediated by autoimmunity, abnormalities in the development of the bile ducts, and defects in embryogenesis, abnormal fetal or prenatal circulation and susceptibility factors. It is increasingly evident that the genetic and epigenetic predisposition combined with the environmental factors to which the mother is exposed are potential triggers for biliary atresia. There is also an indication that a progressive thickening of the arterial middle layer occurs in this disease, suggestive of vascular remodeling and disappearance of the interlobular bile ducts. It is suggested that the hypoxia/ischemia process can affect portal structures in biliary atresia and is associated with both the extent of biliary proliferation and the thickening of the medial layer.

Comparative analysis of cystic biliary atresia and choledochal cysts

OBJECTIVE

Cystic biliary atresia (CBA) is a rare and peculiar type of biliary atresia (BA) that is easily confused with infantile choledochal cysts (CCs). This study explored information for early CBA diagnosis and treatment.

METHOD

The authors retrospectively analyzed the clinical data of 32 children with hilar cysts from January 2013 to May 2021. According to the diagnosis, they were divided into the CBA (n = 12) and CC (n = 20) groups. Patient features, biochemical indexes, preoperative ultrasound characteristics, cholangiography features, and intraoperative findings were analyzed and compared between the two groups.

RESULTS

The alanine aminotransferase, aspartate aminotransferase, total bilirubin, and direct bilirubin levels in the CBA group were higher than in the CCs group (P < 0.05). Additionally, B-mode ultrasound showed a cystic mass in front of the hepatic hilum, and the cyst size was much smaller in the CBA group compared with the CC group (2.2 ± 1.3 cm vs. 6.0 ± 2.2 cm, P < 0.001). Among all of the parameters, cyst width was the most accurate for identifying CBA and CCs. A cutoff value of 2.5 cm (area under the curve, 0.98, P < 0.001) showed 90.9% sensitivity and 95% specificity for cyst size.

CONCLUSION

For children with early-onset severe jaundice, and if the width of the cystic mass was ≤2.5 cm, a diagnosis of CBA was highly likely. Early cholangiography and surgical treatment are necessary for the effective treatment of these infants.

Impact of Age of Patient and Experience of Surgeon on the Outcome after Kasai Portoenterostomy: Can We Delay the Surgery?

INTRODUCTION

 Age of patient and experience of biliary atresia (BA) center are well-known factors associated with early jaundice clearance (EJC) after Kasai portoenterostomy (KPE) in infants with BA. This study focused on the impact of age and surgeon factor on the short-term outcome after KPE within a single center.

MATERIALS AND METHODS

 Fifty-four consecutive infants (18 boys and 36 girls) who underwent KPE from January 2010 to January 2020 were reviewed. KPE was performed in the earliest available operative session once the initial work-up was completed. In group A (n = 41), KPE was performed by surgeon A. In group B (n = 13), KPE was performed by specialists under the supervision of surgeon B (who is the mentor of surgeon A) when surgeon A was not available for operation. The demographics of patients, the EJC (total bilirubin <20 μmol/L within 6 months of KPE), and 2-year native liver survival (NLS) between the two groups were studied.

RESULTS

 The median age at operation was 52 days (range 26-135 days). The overall EJC rate and 2-year NLS were 85.2 and 89.4%, respectively. Group A (p = 0.015) and male gender (p = 0.029) were statistically associated with EJC but not the age at operation (p = 0.101). Group A was also statistically associated with superior 2-year NLS (p = 0.047).

CONCLUSION

 Balancing between the impact of age at operation and the experience of surgeon on the outcome after KPE, our result suggested that KPE may be deferred until a more experienced surgeon to operate.

The Prognosis of Type III Biliary Atresia with Hilar Cyst

OBJECTIVE

To compare the outcome of biliary atresia (BA) patients with and without hilar cyst on preoperative ultrasound.

METHODS

A single center retrospective review of patients of BA with (n = 27) and without hilar cyst (n = 27) over a 5 y period was done. The patients were analyzed using propensity score matching to reduce selection bias. All patients were diagnosed as type III BA by histologic examination and cholangiograms. Clinicopathological characteristics and survival outcomes were compared between the two groups.

RESULTS

There were no significant intergroup differences between baseline characteristics and outcomes after Kasai portoenterostomy surgery in two groups. BA with hilar cyst group showed comparable survival outcomes to the BA without cyst group (cumulative 1-y, 2-y and 5-y overall survival rates with native liver 61.4% vs. 65.8%, P = 0.041; 45.0% vs. 49.0%, P = 0.57; 45.0% vs. 49.0%, P = 0.57). And the Kaplan-Meier survival curves showed no significant difference in cumulative survival with native liver between the two groups (P = 0.58).

CONCLUSIONS

Type III BA with hilar cyst had no better prognosis compared with Type III BA without cyst.

Diagnostic Performance of Transient Elastography in Biliary Atresia Among Infants With Cholestasis

Biliary atresia (BA) is a challenging liver disease in infancy. Early diagnosis of BA is important for timely hepatoportoenterostomy. We evaluated the age-specific diagnostic performance of transient elastography (TE) with a liver stiffness measurement (LSM) greater than 7.7 kPa in BA among infants with cholestasis. A total of 61 infants with cholestasis (5-121 days of age) were enrolled in this prospective follow-up study; 15 infants were BA. Four age groups were defined (≤30, 31-60, 61-90, and 91-180 days). Picrosirius red staining was performed to quantify the percentage of collagen fibers in liver specimens. The utility of an LSM greater than 7.7 kPa for diagnosis of BA among infants with cholestasis was compared among age groups. In all four groups, TE showed high diagnostic power for BA using the criterion of an LSM greater than 7.7 kPa. Positive predictive values were 100%, 100%, and 100% in the groups aged 30 days or younger, 31 to 60 days, and 61 to 90 days, respectively. Respective negative predictive values were 90.9%, 94.7%, and 100%, and respective diagnostic accuracies were 92.9%, 95.2%, and 100%. The positive predictive value, negative predictive value, and diagnostic accuracy were 100%, 100%, and 100%, respectively, for LSM greater than 8.8 kPa in the group aged 91 to 180 days. The LSM was positively correlated with the percentage of collagen fibers stained by picrosirius red (P = 0.03). Conclusion: In this prospective follow-up study, TE had good diagnostic accuracy for differentiation of BA from non-BA cholestasis in infants with cholestasis who were 90 days of age or younger. The LSM was significantly positive correlated with the liver fibrosis status stained by picrosirius red in infants with cholestasis.

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.

Cystic biliary atresia: A distinct clinical entity that may mimic choledochal cyst

Cystic biliary atresia (CBA) is a relatively uncommon but clinically significant variant of biliary atresia. The presence of a cyst in the hepatic hilum on imaging in an infant with cholestasis supports the diagnosis of CBA, but can also be seen in patients with a choledochal cyst—the main differential diagnosis in patients with CBA. The reported case outlines the clinical presentation and imaging findings in a patient with surgically confirmed and treated CBA and emphasizes the importance of distinguishing CBA from choledochal cyst at diagnostic imaging given the disparate timing and type of surgical treatment necessary for successful management of these distinct entities.

Pediatric choledochal cysts: diagnosis and current management

Choledochal cysts are rare congenital disorders first described by Vater and Ezler in 1723. Their exact etiology remains incompletely understood; however, an anomalous pancreaticobiliary union (APBDU) and subsequent reflux of biliary contents into the biliary tree are thought to play a role. Accordingly, APBDU-associated choledochal cyst patients are significantly more likely to have evidence of hepatitis, cholangitis or pancreatitis and pathologically confirmed inflammation. In 1977, Todani and colleagues modified the original Alonso-Lej classification to include five types of CC. Type I and IV are the most common and most likely to be associated with malignancy. The majority of choledochal cysts are diagnosed in childhood. Clinical presentation varies and most often consists of nonspecific abdominal pain. Diagnosis is typically accomplished using multimodality imaging techniques including computed tomography, magnetic resonance imaging, ultrasound and MRCP. The use of diagnostic PTC and ERCP in CC has been largely replaced by MRCP. Appropriate management consists of prompt, complete cyst excision followed by restoration of biliary enteric continuity when necessary. Minimally invasive CC resection in the pediatric population has demonstrated acceptable outcomes. Prognosis is generally excellent; however, malignancy risk remains higher than the general population even after complete surgical excision.