How valuable is ductal plate malformation as a predictor of clinical course in postoperative biliary atresia patients?

Biliary atresia: the development, pathological features, and classification of the bile duct

Biliary atresia is an occlusive biliary disease involving intrahepatic and extrahepatic bile ducts. Its etiology and pathogenesis are unclear. There are many manifestations of bile duct involvement in biliary atresia, but little is known about its occurrence and development. In addition, different classification methods have been proposed in different periods of biliary atresia, each with its advantages and disadvantages. The combined application of biliary atresia classification will help to improve the survival rate of patients with native liver. Therefore, this article reviews the development, pathological features, and classification of intrahepatic and extrahepatic bile ducts in biliary atresia, to provide a reference for the study of the pathogenesis and the choice of treatment methods.

Development of liver inflammatory injury in biliary atresia: from basic to clinical research

Biliary atresia (BA) is a severe cholangiopathy in infants. It is characterized by inflammatory fibro-obliteration of the intra- and extrahepatic bile ducts. Although the restoration of bile flow can be successful after Kasai operation, the rapid progression of liver fibrosis can continue, leading to cirrhosis. It is believed that the progression of liver fibrosis in BA is exacerbated by complicated mechanisms other than the consequence of bile duct obstruction. The fibrogenic cascade in BA liver can be divided into three stages, including liver inflammatory injury, myofibroblast activation, and fibrous scar formation. Recent studies have revealed that the activation of an immune response following bile duct injury plays an important role in promoting the inflammatory process, the releasing of inflammatory cytokines, and the development of fibrogenesis in BA liver. In this article, we summarized the evidence regarding liver inflammatory injury and the possible mechanisms that explain the rapid progression of liver fibrosis in BA.

Identification of Early Clinical and Histological Factors Predictive of Kasai Portoenterostomy Failure

Background: It is impossible to predict which patients with biliary atresia (BA) will fail after Kasai portoenterostomy (KPE). We evaluated the predictive nature of pre-KPE clinical and histological factors on transplant-free survival (TFS) and jaundice clearance. Methods: A retrospective review of patients who received a KPE at our institution (1997−2018) was performed. Primary outcomes were two-year TFS, five-year TFS, and jaundice clearance 3 months after KPE. p < 0.05 was considered significant. Results: Fifty-four patients were included in this study. The two-year TFS was 35.1%, five-year TFS was 24.5%, and 37% patients reached a direct bilirubin (DB) ≤ 2.0 mg/dL 3 months post KPE. The median age at biopsy was younger in the five-year TFS (39.0 (24.5−55.5) vs. 56.0 days (51.0−67.0), p = 0.011). Patients with DB ≤ 1.0 mg/dL 3 months after KPE were statistically younger at biopsy (DB ≤ 1.0 44.0 (26.0−56.0) vs. DB > 1.0 56.0 days (51.0−69.0), p = 0.016). Ductal plate malformation was less frequent in the five-year TFS (16/17, 94.1%, vs. 1/17, 5.9%, p = 0.037). Portal fibrosis (19/23, 82.6%, vs. 4/23, 17.4%, p = 0.028) and acute cholangitis (6/7, 85.7%, vs. 1/7, 14.3%, p = 0.047) occurred less frequently in two-year TFS. Conclusion: Older age at biopsy, acute cholangitis, portal fibrosis, and ductal plate malformation were associated with lower native liver survival. Evaluation in a larger study population is needed to validate these results.

Biliary atresia liver histopathological determinants of early post-Kasai outcome

BACKGROUND

A retrospective chart review of liver histologies in Kasai biliary atresia BA patients operated 1/2017- 7/2019 at our institution was conducted to identify histologic prognostic factors for biliary outcome.

METHODS

Patients with wedge liver biopsies and portal plate biopsies (n = 85) were categorized into unfavorable and favorable outcome, based on a 3-month serum total bilirubin level of <34 μM or mortality. Hepatocellular histologies, presence of ductal plate malformation (DPM) and of large bile duct of ≥ 150 μm diameter size at the portal plate were evaluated.

RESULTS

Total Bilirubin levels> 34 μM correlates with worse 1-year survival. Age at surgery, histologic fibrosis or inflammation does not predict outcome. Potential adverse predictors are severe hepatocellular swelling, severe cholestasis, presence of DPM (n = 24), and portal plate bile duct size < 150 µm (n = 28). In multivariate analyses adjusting for age at Kasai and postop cholangitis, bile duct size and severe hepatocellular swelling remain independent histologic prognosticators (OR 3.25, p = 0.039 and OR 3.26, p = 0.006 respectively), but not DPM.

CONCLUSION

Advanced histologic findings of portal plate bile duct size of <150 µm and severe hepatocellular damage predict poor post-Kasai jaundice clearance and short-term survival outcome, irrespective of Kasai timing.

LEVEL OF EVIDENCE

Level III.

Segmental Atrophy of Explanted Livers in Biliary Atresia: Pathological Data From 63 Cases of Failed Portoenterostomy

OBJECTIVES

Atrophy of the left lateral segment (LLS) is often encountered in liver transplantation (LT) for biliary atresia (BA). To clarify the meaning of the heterogeneous atrophy, we compared the pathological characteristics of the LLS with the right posterior segment (RPS) of BA livers obtained during LT.

METHODS

Among the 116 patients with BA who underwent LT at our hospital between 2014 and 2018, 63 patients with persistent cholestasis after the Kasai portoenterostomy (KP) were selected. Three pathologists evaluated tissues from the LLS and RPS for 5 pathological parameters. Positive areas in whole-slide image observed as portal inflammation, fibrosis, cholestasis, and ductular reaction, were analyzed with automated image quantitation. Moreover, we examined the relationship between the pathological score and the Pediatric End-stage Liver Disease (PELD) score.

RESULTS

The median age at LT was 7 months (range 4-26 months). Inflammation and fibrosis were significantly greater in the LLS than in the RPS (P < 0.001, for both); however, there were no differences in cholestasis, ductular reaction, and hepatocellular damage (P = 0.3, 0.3, and 0.82). The same results were obtained in automated image quantitation. Moreover, the sums of the 5 pathological scores in the LLS showed a significant positive correlation with the PELD score (P = 0.016, rs = 0.3).

CONCLUSIONS

More severe inflammation and fibrosis without cholestasis were observed in the LLS. The segmental atrophy may not be associated with poor bile drainage, but with etiopathogenesis of BA. Moreover, the proper site for biopsy during KP could be the LLS.

Biliary atresia: pathology, etiology and pathogenesis

Biliary atresia is a progressive fibrosing obstructive cholangiopathy of the intrahepatic and extrahepatic biliary system, resulting in obstruction of bile flow and neonatal jaundice. Histopathological findings in liver biopsies include the expansion of the portal tracts, with edematous fibroplasia and bile ductular proliferation, with bile plugs in duct lumen. Lobular morphological features may include variable multinucleate giant cells, bilirubinostasis and hemopoiesis. The etiopathogenesis of biliary atresia is multifactorial and multiple pathomechanisms have been proposed. Experimental and clinical studies have suggested that viral infection initiates biliary epithelium destruction and release of antigens that trigger a Th1 immune response, which leads to further injury of the bile duct, resulting in inflammation and obstructive scarring of the biliary tree. It has also been postulated that biliary atresia is caused by a defect in the normal remodelling process. Genetic predisposition has also been proposed as a factor for the development of biliary atresia.

α-Smooth muscle actin expression predicts the outcome of Kasai portoenterostomy in biliary atresia

BACKGROUND/AIMS

Biliary atresia (BA) is a cholangio-destructive disease of the infant liver presenting with features of obstructive cholangiopathy. The Kasai portoenterostomy (KPE) is the first line of management. The aim of our study was to identify the characteristic features of liver histology in BA that impact the outcome of KPE.

PATIENTS AND METHODS

Data from 30 consecutive children was retrieved from our prospectively maintained database of children undergoing KPE. This included basic demographics, laboratory values and histopathological data from liver biopsy. The stages of fibrosis, presence of ductal plate malformation (DPM), giant cell transformation, extramedullary hematopoiesis and area percentage of α-SMA (α-smooth muscle actin) expression was correlated with jaundice clearance after KPE using standard statistical tests. Native liver survival was computed.

RESULTS

Overall, 13 (43%) children cleared jaundice in this series and 10 (33%) are alive with native liver. Lower area percent expression of α-SMA correlated with increased probability of jaundice clearance after KPE (P < 0.001). There was no correlation between stage of fibrosis and jaundice clearance (P = 0.52). DPM, giant cell transformation and extramedullary hematopoiesis did not correlate with outcome. All children who are alive with native liver had lower expression of α-SMA.

CONCLUSION

α-SMA expression may be a potential predictor of jaundice clearance and native liver survival after KPE.

Clinical and pathological features of patients with biliary atresia who survived for more than 5 years with native liver

PURPOSE

The objective of this study was to determine the predictive index for prognosis in patients with biliary atresia (BA).

METHODS

A total of 71 patients were divided into two groups. Group A included 39 postoperative BA patients who survived for more than 5 years with normal liver function and did not present cirrhosis, and group B included 32 patients who died from liver failure within 1 year after surgery. The clinical data of the two study groups were compared, and liver pathology was evaluated using a scoring system.

RESULTS

The average age and weight were similar in the two groups (64.1 ± 16.8 days vs. 60.7 ± 19.3 days, p > 0.05; 4.9 ± 0.9 kg vs. 4.7 ± 0.8 kg, p > 0.05). There were no significant intergroup differences in preoperative total bilirubin (TB), direct bilirubin (DB), alanine transaminase, aspartate transaminase, and international normalized ratio. The preoperative levels of gamma-glutamyl transpeptidase (γ-GT) and albumin in group A were significantly higher than those in group B (γ-GT: 956.8 ± 503.8 IU/L vs. 620.2 ± 437.1 IU/L, p = 0.00; ALB: 40.8 ± 2.5 g/L vs. 36.8 ± 3.6 g/L, p = 0.04), whereas alkaline phosphatase was significantly lower in group A compared to group B (512.2 ± 224.6 IU/L vs. 631.7 ± 254.7 IU/L, p = 0.02). The postoperative TB and DB after 2 weeks of the Kasai procedure decreased significantly more in group A than in group B (TB: 53.9 vs. 21.4%, p = 0.00; DB: 51.0 vs. 22.7%, p = 0.00), whereas γ-GT increased significantly less in group A than in group B (48.3 vs. 142.1%, p = 0.00). Cystic structures were observed at the porta hepatis on ultrasound in more patients from group A (28.2 vs. 3.2%, p < 0.00). There was no significant difference in the total pathological score between the two groups (p = 0.38) whereas the score of bile plugs was significantly higher in group A (0.95 vs. 0.38, p = 0.03).

CONCLUSION

The cystic structures observed at the porta hepatis on ultrasound preoperatively and the rapid decrease in TB and DB within 2 weeks postoperatively predict good long-term prognosis, whereas a significant increase in γ-GT with a lower preoperative level predicts poor long-term prognosis. The development of bile plugs may be an indicator of favorable prognosis.

Biliary atresia: Where do we stand now?

The pathway from clinical suspicion to establishing the diagnosis of biliary atresia in a child with jaundice is a daunting task. However, investigations available help to point towards the correct diagnosis in reasonable time frame. Imaging by Sonography has identified several parameters which can be of utility in the diagnostic work up. Comparison of Sonography with imaging by Nuclear medicine can bring out the significant differences and also help in appropriate imaging. The battery of Biochemical tests, available currently, enable better understanding of the line-up of investigations in a given child with neonatal cholestasis. Management protocols enable standardized care with optimal outcome. The place of surgical management in biliary atresia is undisputed, although Kasai procedure and primary liver transplantation have been pitted against each other. This article functions as a platform to bring forth the various dimensions of biliary atresia.

Diagnostic and Prognostic Significance of Various Histopathological Features in Extrahepatic Biliary Atresia

INTRODUCTION

Extrahepatic biliary atresia is a progressive disorder characterised by fibroinflammatory obliteration or stenosis of the extrahepatic biliary tree leading to obstruction of bile flow and cholestatic jaundice. It is the most common cause for cholestasis in newborn. Histopathological criteria for diagnosing biliary atresia from liver biopsy have not been clearly defined.

AIM

This study was undertaken to analyse the significance of the various histopathological features in diagnosis and prognosis of extrahepatic biliary atresia from liver biopsy specimens.

MATERIALS AND METHODS

This was a retrospective study of 43 cases of extra-hepatic biliary atresia diagnosed and treated at a tertiary care hospital between January 2010 to December 2014. Formalin fixed paraffin embedded liver biopsy tissues were processed by standard technique and the slides were stained with haematoxylin and eosin. All the slides were reviewed and graded by a semi-quantitative scoring system. Features such as increased age at kasai's portoenterostomy, portal fibrosis, bile duct proliferation, cholestasis, portal inflammation and duct plate malformation were studied. Statistical analysis was worked out using SPSS 17.0 (statistical package for the social science software). Chi-square test was used to find association between various parameters with respect to mortality and Kaplan-Meier estimator was used for survival analysis of the population under study.

RESULTS

In this study comprising of 43 cases, only 6 cases (13.95%) were alive at the end of 6 months follow-up. Twenty patients who died and the 17 cases with poor survival had greater degrees of fibrosis, bile duct proliferation and cholestasis. Majority of the cases with duct plate malformation expired inspite of earlier surgical intervention. Thus proving the association of fibrosis, bile duct proliferation, cholestasis and duct plate malformation with the survival and prognosis of biliary atresia cases. Age at surgery did not show any correlation with prognosis as cases operated even at <60 days had poor survival.

CONCLUSION

From this study it can be concluded that in extrahepatic biliary atresia patients, presence of duct plate malformation, greater degrees of fibrosis, bile duct proliferation and cholestasis were strongly associated with poor prognosis.

Impact of ductal plate malformation on survival with native liver in children with biliary atresia

PURPOSE

Ductal plate malformation (DPM) like arrays in the liver which resemble the characteristic persistent embryonal ductular structures have been shown to adversely affect the outcome of Kasai portoenterostomy (KPE) in biliary atresia (BA). We studied the impact of DPM on survival with native liver (SNL) in children with BA who underwent liver transplantation (LT) after KPE as well as those who underwent primary LT without KPE.

METHODS

Records of children with BA who underwent LT in our institute were reviewed and divided into three groups-Group 1 had primary LT because of delayed diagnosis of BA and synthetic liver failure, Group 2 had LT for synthetic liver failure after a failed KPE, and Group 3 had LT despite clearing jaundice after KPE for other indications. The impact of DPM on SNL was analyzed using standard statistical means.

RESULTS

In Group 1 (n = 26) and Group 2 (n = 26), the incidence of DPM was high and was associated with a significantly shorter SNL compared to children with no DPM. The incidence of DPM was significantly lower in Group 3 (n = 13).

CONCLUSION

DPM shortens SNL and influences the pathogenesis of disease progression in children with BA who had synthetic liver failure requiring transplantation either because of a failed KPE or due to a delay in diagnosis. Its incidence is low in children who cleared jaundice after KPE and needed transplantation for other indications at a later age. The presence of DPM signifies an adverse outcome for the disease.

Ductal plate malformation in patients with biliary atresia

The presence of ductal plate malformation (DPM+) on liver histology in children with biliary atresia (BA) is a marker of early intrauterine disease onset and an indication of an unfavorable prognosis. We studied the prognostic value of DPM in infants with BA after hepatoportoenterostomy (HPE). We reviewed 28 BA patients who underwent HPE in a single medical center. We examined the time of jaundice onset after delivery (conjugated hyperbilirubinemia): early onset (fetal phenotype with no jaundice-free interval) vs. late onset (perinatal phenotype with jaundice-free interval) and the presence or absence of DPM (DPM+ or DPM-) histopathology. Primary outcome was jaundice clearance at 3 months after HPE and survival with native liver (SNL). Eight children had fetal and 20 had perinatal BA (8 DPM+, 12 DPM-). At 3 months after HPE, no patients with fetal BA had achieved jaundice clearance, while jaundice clearance was achieved in five patients with DPM+ perinatal disease and four patients with DPM- perinatal BA (P = 0.03, comparing all three groups; P = 0.36, comparing DPM+ vs. DPM- perinatal patients). Median SNL was 8.6 months for fetal BA patients, 148.2 months for DPM+ perinatal BA patients, and 93.2 months for DPM- perinatal BA patients (log-rank test, P < 0.001, comparing all three groups; P = 0.59, comparing DPM+ vs. DPM- perinatal patients). After adjusting for BA type, age older than 2 months at HPE was associated with worse SNL [P = 0.03; hazard ratio = 4.0 (95 % CI, 1.1-14.2)].

CONCLUSIONS

Early onset of jaundice, regardless of DPM histology, was the most ominous sign of poor outcome in infants with BA after HPE.

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.