Does "cystic" biliary atresia represent a distinct clinical and etiological subgroup? A series of three cases

Preoperative imaging findings to predict 2-year native liver survival after the Kasai procedure in patients with biliary atresia

OBJECTIVES

To investigate the feasibility of using preoperative imaging indices to predict 2-year native liver survival after the Kasai procedure in patients with biliary atresia (BA).

MATERIALS AND METHODS

The retrospective review included 190 BA patients who underwent the Kasai procedure between 2000 and 2020, with preoperative US and/or MRI, excluding cases with less than 2-year follow-up period. Multivariable logistic regression analysis was performed to identify imaging indices to predict 2-year native liver survival. Kasai failure was defined as the need for liver transplantation or death within 2 years of the Kasai procedure.

RESULTS

Of the 90 patients included, all had preoperative US, and 61 also had MRI. Kasai failure occurred in 52% (47/90). Preoperative US identified gallbladder length (OR 0.40, 95% CI 0.17-0.95, p = 0.039; cutoff 1.6 cm, AUC 67.66) and biliary cysts (OR 24.64, 95% CI 1.97-308.08, p = 0.013) as significant Kasai failure predictors, with a combined accuracy of 73% (60/82). For patients having both preoperative US and MRI, significant predictors were hepatic artery diameter (OR 6.75, 95% CI 1.31-34.88, p = 0.023; cutoff 2 mm, AUC 73.83) and biliary cysts (OR 23.89, 95% CI 1.43-398.82, p = 0.027) on US, and gallbladder length (OR 0.25, 95% CI 0.08-0.76, p = 0.014; cutoff 1.2 cm, AUC 74.72) and spleen size (OR 2.53, 95% CI 1.02-6.29, p = 0.045; cutoff 6.9 cm, AUC 73.72) on MRI, with a combined accuracy of 85% (52/61).

CONCLUSION

Preoperative US and/or MRI enhance the 2-year native liver survival prediction in BA patients after the Kasai procedure.

CLINICAL RELEVANCE STATEMENT

BA patients with hepatic artery diameter > 2 mm (US), gallbladder length < 1.6 cm (US) or < 1.2 cm (MRI), spleen size > 6.9 cm (MRI), and absence of biliary cysts (US/MRI) have a decreased likelihood of 2-year native liver survival.

KEY POINTS

• Preoperative US and/or MRI can predict the probability of achieving 2-year native liver survival following the Kasai procedure. • Combining US and MRI improved the accuracy to 85% for predicting 2-year native liver survival in BA patients. • The hepatic artery diameter > 2 mm (US), gallbladder length < 1.6 cm (US) or < 1.2 cm (MRI), spleen size > 6.9 cm (MRI), and no biliary cysts (US/MRI) are significant predictors of Kasai failure in patients with biliary atresia.

TGF-β Signaling Plays a Pivotal Role During Developmental Biliary Atresia in Sea Lamprey (Petromyzon marinus)

Biliary atresia (BA) is a rare neonatal disease with unknown causes. Approximately 10% of BA cases develop in utero with other congenital defects that span a large spectrum of disease variations, including degeneration of the gall bladder and bile duct as well as malformation of the liver, intestines, and kidneys. Similar developmental alterations are manifested in a unique animal model, the sea lamprey (Petromyzon marinus), in which BA occurs naturally during metamorphosis. With the likelihood of conserved developmental mechanisms underlying organogenesis and degeneration, lamprey developmental BA may be a useful model to infer mechanisms underlying human embryonic BA. We reasoned that hepatobiliary transcriptomes regulate the transition between landmark stages of BA. Therefore, we examined sea lamprey hepatobiliary transcriptomes at four stages (M0, metamorphic stage 0 or larval stage, no BA; M2, metamorphic stage 2, onset of BA; M5, metamorphic stage 5, BA, and heightened hepatocyte proliferation and reorganization; and JV, juvenile, completion of BA) using messenger RNA sequencing and Kyoto Encyclopedia of Genes and Genomes pathway analyses. We found gene-expression patterns associated with the transition between these stages. In particular, transforming growth factor β (TGF-β), hedgehog, phosphatidylinositol-4,5-bisphosphate 3-kinase-Akt, Wnt, and mitogen-activated protein kinase pathways were involved during biliary degeneration. Furthermore, disrupting the TGF-β signaling pathway with antagonist or small interfering RNA treatments at the onset of BA delayed gall bladder and bile duct degeneration. Conclusion: Distinctive gene-expression patterns are associated with the degeneration of the biliary system during developmental BA. In addition, disrupting TGF-β signaling pathway at the onset of BA delayed biliary degeneration.

Obliterative cholangiopathy in acquired cystic biliary atresia type III after cyst perforation: a case report

Background

In biliary atresia, the disease process of obliterative cholangiopathy may begin in the perinatal period; however, no chronological evidence exists on how the cholangiopathy progresses to biliary obliteration.

This is the first acquired case with the final diagnosis of type III cystic biliary atresia with an extrahepatic biliary cyst which showed the progression of obliterative cholangiopathy in chronological order after birth.

Case presentation

An 81-day-old girl presented with acute abdominal distress due to bilious peritonitis caused by biliary cyst perforation, for which she underwent emergency biliary drainage. Postoperative images showed a dilated common bile duct and hepatic ducts bilaterally, with flow of the contrast medium to the duodenum through the dilated common bile duct. Biochemistry of the bile collected during and after the operation revealed elevated levels of pancreatic enzymes in the bile from the gallbladder. The patient was diagnosed as having a congenital choledochal cyst and underwent laparotomy at 120 days of age which revealed that she had pancreaticobiliary maljunction. The biliary cyst was resected at the narrow portion just above the junction with the main pancreatic duct. During dissection up to the hepatic hilum, we found that the hilar hepatic ducts were bilaterally replaced by fibrous tissue and were obstructed, leading to a diagnosis of type III a1, μ biliary atresia. The fibrous tissue was excised, and hepatic portoenterostomy was performed according to the Kasai procedure. The patient’s postoperative course was uneventful and the jaundice resolved within 1 month. She has had normal liver function tests with no episode of cholangitis for 3 years after discharge.

Conclusions

We demonstrated the process of acquired type III biliary atresia in a patient with cystic biliary atresia and biliary cyst perforation. To the best of our knowledge, this is the first case of acquired cystic biliary atresia showing chronological progression of the course of obliterative cholangiopathy, providing a better understanding of the development of type III biliary atresia as an acquired disease.

Pediatric cholangiopathies: diseases of the gallbladder and biliary tract

Pediatric gallbladder and bile duct disease encompasses a broad spectrum of processes, from congenital to developmental to neoplastic. We describe normal pediatric biliary anatomy and summarize the most common pathologic entities, with a focus on non-invasive imaging techniques and findings. Ultrasound is the first-line imaging modality in children with suspected biliary pathology based on its widespread availability, cost effectiveness, and lack of ionizing radiation. MRI and MRCP are often used for further evaluation in cases of diagnostic uncertainty and for surgical planning.

Genetic contributors and modifiers of biliary atresia

To date, the etiology and pathogenic underpinning of the progression of the most prevalent serious neonatal liver disease, biliary atresia, remains elusive. This disease presents as an aggressive form of neonatal cholestasis characterized by the destruction and obliteration of the extrahepatic bile ducts within the first few weeks of life and a rapid progression of biliary fibrosis, likely due to unremitting cholestasis and retention of biliary constituents including bile acids. In ∼5% of patients, biliary atresia is associated with laterality features, suggesting a genetic underpinning to a disease that begins soon after birth. However, biliary atresia does not occur within families and twins are discordant, indicating an absence of strict mendelian inheritance. Despite this, genes related to bile duct dysmorphogenesis/ciliopathies overlapping with features of biliary atresia in both humans and nonhuman model systems have been proposed. Taken together, strict genetic etiologies leading to a common pathway of a neonatal cholangiopathy resulting in biliary atresia remain elusive. Contributions from fibrogenesis- and inflammation-based studies suggest that early engagement of these pathways contributes to disease progression, but a recent double-blind study did not suggest any benefit from early use of corticosteroids. However, there are genetic contributions to the adaptation and response to cholangiopathies and cholestasis that may be present in certain populations that likely impact upon the response to hepatoportoenterostomy and subsequent biliary tract function. Studies utilizing next generation sequencing technologies (e.g., exome analysis) are ongoing in several laboratories around the world; they are expected to provide insights into genetic contributions to biliary atresia outcomes. Altogether, combinations of exome sequencing and large population studies are expected to reveal causative and modifying genes relevant to patients with biliary atresia as a means to provide therapeutic targets and potential opportunities for genetic screening.

Biliary atresia: a multidisciplinary approach to diagnosis and management

CONTEXT

Biliary atresia is an inflammatory cholangiopathy of infancy that results in progressive fibrosis and obliteration of bile ducts and represents the main indication for liver transplant in young children. In spite of extensive investigation, its etiology has remained poorly understood. Timely surgical intervention (Kasai procedure) may result in significant benefit to these patients and represents the final goal of an accurate diagnostic evaluation.

OBJECTIVE

To present an overview of biliary atresia, including clinical and surgical approaches to this disease, with emphasis on the histopathologic evaluation.

DATA SOURCES

Review of relevant literature indexed in PubMed (US National Library of Medicine).

CONCLUSION

A well-coordinated multidisciplinary approach is required in the assessment of suspected cases of biliary atresia. Pathologic examination of biopsy specimens is an integral part of the diagnostic algorithm and, therefore, plays a pivotal role in the diagnostic evaluation of this disease.

Toll-like receptor mRNA expression in liver tissue from patients with biliary atresia

BACKGROUND AND AIM

Inappropriate host immunological reactions against unknown ligands via the Toll-like receptor (TLR) cascades may trigger progressive inflammatory biliary destruction that manifests as biliary atresia (BA) in newborns or infants. The aim of the study was to clarify the role of the innate immune system in the development of BA.

PATIENTS AND METHODS

Liver tissue was obtained from 49 patients with pediatric hepatobiliary diseases: 19 with BA, 21 with choledochal cysts, and 9 with other hepatobiliary diseases. BA samples obtained during the initial portoenterostomy and reoperation or liver transplantation (LT) were classified as early and late BA groups, respectively. Of the early BA group, those requiring LT were designated as the LT group, and the others were designated as the non-LT group. The mRNA expression levels of TLRs 2, 3, 4, 7, and 8 were determined by real-time quantitative reverse transcription-polymerase chain reaction and were compared between groups. The correlation between TLR mRNA expression level and age at sampling was examined for each TLR in the patients with BA.

RESULTS

TLR8 mRNA, encoding the receptor for single-stranded RNA, was significantly higher in the early BA group, compared with non-BA groups (P = 0.008). Within the BA group, mRNA levels of TLRs 2 and 8 were significantly higher in the early group than in the late group (P = 0.02 and 0.006, respectively), despite there being no significant correlation between TLR mRNA expression and age at sampling, except for TLR7 (r = 0.77, P = 0.001). Compared with the non-LT group, the LT group demonstrated significantly higher mRNA expression of TLRs 3 and 7 (P = 0.02 and 0.01, respectively).

CONCLUSIONS

Innate immune responses may contribute to the initiation and progression of BA. Severe inflammation characteristic of BA around the time of the first operation may abate postoperatively, but determination of selected TLR mRNA expression levels in the liver at the time of Kasai portoenterostomy may assist in predicting the prognosis of patients with BA.

Excellent long-term outcome of hepaticojejunostomy for biliary atresia with a hilar cyst

BACKGROUND

Biliary atresia (BA) with hilar cyst is an uncommon variant, which constitutes less than 10% of all types of BA, and the operative procedure for this type of BA remains controversial.

METHODS

We have had 200 cases with BA from 1963 to 2008 in our institute and our branch hospitals, in which 12 cases (6%) were BA with a hilar cyst. The clinical records of all cases were evaluated retrospectively.

RESULTS

Twelve BA patients with a hilar cyst included 2 boys and 10 girls. The diagnosis of BA was confirmed by intraoperative cholangiography (cloudy or treelike pattern). In all 12 cases, a hepaticojejunostomy was performed at a median age of 71.6 days (range, 24-136 days). The follow-up periods were 1.2 to 23.2 years. The current mean total bilirubin level was 0.8 mg/dL (range, 0.2-3.5 mg/dL), and the mean direct bilirubin level was 0.2 mg/dL (range, 0.0 to 0.8 mg/dL). Methylprednisolone or oral prednisolone was administered in 8 cases after operation, and 10 of 12 cases achieved a jaundice free state. The postoperative complications were cholangitis (n = 10), gastroesophageal varices (n = 7), splenomegaly (n = 3), ileus (n = 1), and pulmonary hypertension (n = 1). The overall survival rate with a native liver was 10 (83.3%) of 12 cases, of which 9 cases were jaundice-free and only 1 case showed recurrent jaundice. The other 2 cases underwent living-donor liver transplantation at age of 2 and 20 years, respectively, and they are currently doing well.

CONCLUSIONS

Most cases of BA with a hilar cyst achieved excellent clinical outcome after a hepaticojejunostomy.

Biliary atresia: how medical complications and therapies impact outcome

Biliary atresia (BA) is a progressive fibro-obliterative disease of the extrahepatic biliary tree that presents with biliary obstruction in the neonatal period. Untreated, BA is a uniformly fatal disease and, yet, even with our existing therapies, at least 50% of children with BA will undergo liver transplantation by the age of 2 years. Current treatment strategies are, at best, palliative; they focus on prompt diagnosis, supportive nutritional care and interventions for sequelae. The purpose of this article is to discuss the current treatment paradigm for BA and to assess the impact these strategies have on outcomes. As more children with BA survive into adulthood with their native liver, it is important to understand which factors predict good and poor outcomes.

Recent advances in biliary atresia: prospects for novel therapies

BACKGROUND

Biliary atresia (BA) is a progressive fibro-obliterative disease of the extrahepatic biliary tree that presents with biliary obstruction before 2 months of age. Untreated BA is a uniformly fatal disease and even with our current therapies only 50% of children with BA will be transplant-free by 2 years of age. Despite descriptions of this disorder dating back to the 1800s our current therapies are palliative. They focus on prompt diagnosis, supportive nutritional care and interventions for sequelae.

OBJECTIVE

To present the literature supporting current treatment strategies and potential future therapies.

METHOD

Each of the aspects of care is described and the literature about nuances of care is provided.

CONCLUSION

Therapies will not improve outcomes until novel treatments are introduced, such as those suggested, which may intervene in the inflammatory or fibrotic steps of the disease process.

Cystic biliary atresia: an etiologic and prognostic subgroup

INTRODUCTION

Cystic biliary atresia (CBA) is an uncommon variant of biliary atresia (BA) in which prognosis may be relatively favorable but liable to misdiagnosis as choledochal cyst, and potentially offers insights into the etiology of BA. Because some cases can be detected antenatally, CBA in general may have its origins in utero life. We assessed our experience with CBA.

METHODS

Single-center retrospective review of infants with CBA over a 13-year period (January 1994 to December 2006) was done. Data are given as medians (range).

RESULTS

Of 270 infants with BA, 29 (9 male) were identified as CBA. Antenatal ultrasonography had detected an abnormality in 12 (41%) infants at a median of 22 weeks (17-34 weeks) of gestation. All infants underwent postnatal excision and Kasai portoenterostomy (KP). Those with antenatally detected CBA came to surgery younger (36 [14-67] vs 48 days [35-147 days], P = .004). Twenty cysts (69%) had a fibroinflammatory wall with no biliary epithelial lining and 6 (26%) contained bile. Age at KP was significantly and positively correlated (r = 0.46, P = .01) with liver fibrosis, as assessed in liver biopsy materials obtained at KP, but not with grade of "hepatocyte disarray" (P = .74). Twenty infants (69%) cleared their jaundice (bilirubin <20 mumol/L) within 6 months after KP. Age at KP markedly affected outcome.

CONCLUSION

Cystic BA is a clinically distinct variant of BA. Despite onset in prenatal life, earlier than presumed for isolated BA, it has a better prognosis, particularly with early surgery.

Screening and outcomes in biliary atresia: summary of a National Institutes of Health workshop

Biliary atresia is the most common cause of end-stage liver disease in the infant and is the leading pediatric indication for liver transplantation in the United States. Earlier diagnosis (<30-45 days of life) is associated with improved outcomes following the Kasai portoenterostomy and longer survival with the native liver. However, establishing this diagnosis is problematic because of its rarity, the much more common indirect hyperbilirubinemia that occurs in the newborn period, and the schedule for routine infant health care visits in the United States. The pathogenesis of biliary atresia appears to involve immune-mediated fibro-obliteration of the extrahepatic and intrahepatic biliary tree in most patients and defective morphogenesis of the biliary system in the remainder. The determinants of the outcome of portoenterostomy include the age at surgery, the center's experience, the presence of associated congenital anomalies, and the postoperative occurrence of cholangitis. A number of screening strategies in infants have been studied. The most promising are early measurements of serum conjugated bilirubin and a stool color card given to new parents that alerts them and their primary care provider to alcholic stools. This report summarizes a National Institutes of Health workshop held on September 12 and 13, 2006, in Bethesda, MD, that addressed the issues of outcomes, screening, and pathogenesis of biliary atresia.