Postoperative changes of intrahepatic portal veins in biliary atresia--a 3-D reconstruction study

Lymphangiogenesis in the liver of biliary atresia

BACKGROUND

Lymphatic vessels (LVs) play a crucial role in immune reactions by serving as the principal conduits for immune cells. However, to date, no study has analyzed the morphological changes in the LVs of patients with biliary atresia (BA). In this study, we aimed to determine the morphological changes in the LVs irrigating the liver in patients with BA, elucidate their correlations with the morphology of the portal vein (PV) branches, and discuss their etiopathogenetic significance.

METHODS

Morphometric analyses of liver biopsy specimens from patients treated between 1986 and 2016 were performed. The parameters measured were as follows: the whole liver area of the specimen, fibrotic area, number of LVs, LVs without patent lumen (designated as Ly0) and PV branches, and diameters of the LVs with patent lumen and the PVs.

RESULTS

The numbers of LVs, Ly0, and PV branches per unit area of the whole liver specimen were significantly higher in patients with BA than in control participants with liver disease and those with normal livers. However, no correlation was observed between the fibrotic area and the average diameter of LVs or PVs, and between the fibrotic area and the number of LVs or PV branches. Furthermore, no correlation was observed between the total number of LVs and the number of PV branches.

CONCLUSIONS

The present study showed a significant increase in the number of total LVs and Ly0, characterized by a high Ly0 to total LVs ratio, suggesting that lymphangiogenesis occurs in the liver of patients with BA.

Liver Explants of Biliary Atresia Patients Transplanted in Adulthood Show Features of Obliterative Portal Venopathy: Case Series and Guidelines for Pathologic Reporting of Adult Explants

CONTEXT.—

Biliary atresia (BA) patients can have portal vein (PV) abnormalities.

OBJECTIVE.—

To investigate the explant pathology of BA patients transplanted in adulthood with a focus on portal venous abnormalities.

DESIGN.—

Adult BA liver explants were reviewed, along with prior biopsies, Kasai portoenterostomy (KP), and relevant medical records.

RESULTS.—

Three explants were identified; all patients were female, with age at diagnosis, KP, and liver transplantation (LT) as follows: (1) less than 1 week, 8 days, and 25 years; (2) 15 weeks, 16 weeks, and 32 years; and (3) 7 weeks, 8 weeks, and 33 years, respectively, with normalization of conjugated bilirubin within 6 months of KP and development of portal hypertension (PHTN) within 3 years of KP for all 3. The first 2 had recurrent cholangitis. Duration of pre-LT PHTN was 22, 29, and 30 years, and that of pre-LT cholangitis was 9, 3, and 0 years, respectively. All 3 explants showed hilar and extrahepatic fibromyxoid intimal hyperplasia of the PV with parenchymal hepatoportal sclerosis. Cholestasis was limited to those with a history of cholangitis. Patient 3, without cholangitis, showed delicate septal fibrosis with peripheral accentuation without biliary cirrhosis.

CONCLUSIONS.—

In the context of a functioning KP, cholestasis and biliary cirrhosis are likely related to recurrent cholangitis, which may or may not occur after KP. In the absence of biliary cirrhosis, PHTN may be secondary to obliterative venopathy. Adult BA explants should be sampled thoroughly, with a focus on hilar/perihilar connective tissue to include PV branches. Explants may not show biliary cirrhosis and should be reported with appropriate clinicopathologic correlation.

Liver Transplantation for Biliary Atresia in Adulthood: Single-Centre Surgical Experience

Background: Biliary atresia (BA) is the most common indicator for liver transplant (LT) in children, however, approximately 22% will reach adulthood with their native liver, and of these, half will require transplantation later in life. The aim of this study was to analyse the surgical challenges and outcomes of patients with BA undergoing LT in adulthood. Methods: Patients with BA requiring LT at the age of 16 or older in our unit between 1989 and 2020 were included. Pretransplant, perioperative variables and outcomes were analysed. Pretransplant imaging was reviewed to assess liver appearance, spontaneous visceral portosystemic shunting (SPSS), splenomegaly, splenic artery (SA) size, and aneurysms. Results: Thirty-four patients who underwent LT for BA fulfilled the inclusion criteria, at a median age of 24 years. The main indicators for LT were synthetic failure and recurrent cholangitis. In total, 57.6% had significant enlargement of the SA, 21% had multiple SA aneurysm, and SPSS was present in 72.7% of the patients. Graft and patient survival at 1, 5, and 10 years was 97.1%, 91.2%, 91.2% and 100%, 94%, 94%, respectively Conclusions: Good outcomes after LT for BA in young patients can be achieved with careful donor selection and surgery to minimise the risk of complications. Identification of anatomical variants and shunting are helpful in guiding attitude at the time of transplant.

Biliary Atresia Patients With Successful Kasai Portoenterostomy Can Present With Features of Obliterative Portal Venopathy

OBJECTIVE

Study of liver explants of biliary atresia (BA) patients with successful Kasai portoenterostomy (KP).

METHODS

Pathology and medical records of BA liver explants from January 2009 to June 2018 with successful KP were reviewed along with appropriate controls.

RESULTS

Fourteen out of 68 (20.6%) BA patients with LT had a successful KP. Median age at BA diagnosis, KP and LT was 60.5 days, 61 days, and 10 years, respectively, with conjugated bilirubin (c-bil) normalizing at 12.5 weeks after KP. Advanced fibrosis was diffuse in 2/14 (14.3%) explants, limited to periphery in 11/14 (78.6%) and absent in 1. Hilar partial nodular transformation (PNT) was seen in 11 explants (78.6%) and diffuse nodular regenerative hyperplasia (NRH) in 2 (14.3%). Areas of PNT and NRH showed diffuse portal sclerosis (100%), complete and incomplete portal vein (PV) stenosis (100%), PV herniation (100%), hypervascular portal tracts (20%), periportal abnormal vessels (100%), abundant lymphatic collaterals (100%), mild medial hepatic arterial hypertrophy (100%), and delicate fibrous septae (100%). Extrahepatic PVs showed variable luminal occlusion with mean PV intima to full thickness ratio of 0.6 +/- 0.11; significantly higher than age-matched noncirrhotic (n = 27, 0.08 +/- 0.09; P < 0.0001) and cirrhotic controls (n = 19, 0.34 +/- 0.2; P = 0.0015); and comparable to BA patients with failed KP (P = 0.82) and without KP (P = 0.04).

CONCLUSIONS

BA patients with successful KP can present with obliterative portal venopathy (OPV). In the context of optimal bile drainage, portal hypertension may not be because of advanced parenchymal fibrosis but possibly because of OPV. Vascular abnormalities of the PV system should be investigated in BA patients.

Microvascular proliferation of the portal vein branches in the liver of biliary atresia patients at Kasai operation is associated with a better long-term clinical outcome

AIM OF THE STUDY

We previously showed an increased number of smaller portal vein (PV) branches in the portal areas of liver biopsy specimens of biliary atresia (BA) patients. We evaluated the correlation between this histopathological feature and the prognosis.

PATIENTS AND METHODS

Twenty-five consecutive patients with BA encountered between 2000 and 2012 were classified into three prognostic groups based on their postoperative outcomes: Excellent (n = 11) for native-liver survivors with a normal liver function, Good (n = 6) for native-liver survivors with liver dysfunction, and Poor (n = 8) for survivors after liver transplant or on a waiting list. Data from morphometrical analyses, including the fibrotic portal area, numbers of PVs, diameter and total area of PV branches, were statistically compared among the three groups.

MAIN RESULTS

The number of PV branches per unit area of the whole-liver specimen in the poor prognostic group was significantly lower than that in the excellent group (3.1 ± 0.6 vs. 5.2 ± 2.0/mm², p = 0.03). There were no significant differences in the other parameters.

CONCLUSIONS

This is the first report on the relationships between morphometrically analyzed PV branches and the postoperative course in BA patients. The portal venous system is involved as the primary lesion in BA.

Morphometric demonstration of portal vein stenosis and hepatic arterial medial hypertrophy in patients with biliary atresia

PURPOSE

Portal hypertension in patients with biliary atresia (BA) is generally thought to result from portal vein (PV) narrowing secondary to hepatic fibrosis. To test the hypothesis, we morphometrically analyzed the PVs and hepatic arteries (HAs).

METHODS

Morphometrical analyses of 25 BA and 26 non-BA liver biopsy specimens from patients treated from 2000 to 2014. The total specimen area, the fibrotic portal area, vessel diameter and medial thickness of the HAs were measured.

RESULTS

The PV diameter in BA patients was significantly smaller than that in non-BA patients. In BA, the numbers of normal-sized PVs and capillaries were decreased and increased, respectively. The PV diameter was not significantly correlated with the degree of fibrosis. We newly found that medial hypertrophy and the HA diameter increased with the number of endothelial cells in BA. The PV diameter was not significantly correlated with the medial thickness and was positively correlated with the HA diameter in BA.

CONCLUSIONS

The narrowing of the PV is unlikely to occur secondarily to liver fibrosis. The medial hypertrophy of the HA is not correlated with the decrease in the PV blood flow. These findings seem to be unique to the primary vascular lesions of BA.

Ethnic variation in the incidence of biliary atresia correlates with the frequency of the most prevalent haplotype in its population

The cause of biliary atresia (BA) remains an enigma. However, an ethnic diversity in the incidence of BA is so unique that anthropological approach may provide some etiopathogenetic implications in the disease mechanism. We previously reported that an association of maternal microchimerism (MMc) in BA and a significant compatibility of HLA-A between the patient with BA and their mother. Across the 10 countries (Japan, South Korea, Taiwan, Philippines, New Zealand (Maori population), UK, France, Germany, Norway, and Sweden), we determined the frequency of the most prevalent HLA haplotypes of each country from Allele Frequency Database and found that it was significantly correlated with the incidence of BA of the respective country (p = 0.0126). This observation better fits the MMc theory as an etiopathogenesis, that is, maternal effector cells are likely to migrate into the fetus in a relatively homogenous population and may damage the developing bile duct structure and portal vein endothelium, depending on materno-fetal tolerance and immunity.

Unique manifestations of biliary atresia provide new immunological insight into its etiopathogenesis

Biliary atresia (BA) is a unique cholestatic disease of newborns with a background of exaggerated immune response in the liver of unknown mechanism. Three hypotheses have been proposed; autoimmune type of cholangiopathy triggered by virus infection, graft-versus-host disease type of immune-mediated disease associated with maternal microchimerism and ductal plate malformation theory. Researchers on virus infection theory have experimentally explored immune process causing cholangiopathy on murine models of this disease, while in maternal microchimerism hypothesis were detected maternal cells in the BA patients' liver, of which roles are yet to be determined. Ductal plate malformation theory is an intriguing hypothesis in the sense that it suggests the onset of this disease is in the first trimester. This theory can be secondary to either one of these two immune-related insults. In this review, four unique points are focused; (1) the timing of onset, (2) hepatitis-like pathological picture, (3) heterogenous atrophy of the liver segments when advanced, and (4) swollen lymph nodes at the porta hepatis. These unique clinicopahtological aspects of this disease should be well explained by these hypotheses.

Liver and systemic hemodynamics in children with cirrhosis: Impact on the surgical management in pediatric living donor liver transplantation

Cirrhosis in adults is associated with modifications of systemic and liver hemodynamics, whereas little is known about the pediatric population. The aim of this work was to investigate whether alterations of hepatic and systemic hemodynamics were correlated with cirrhosis severity in children. The impact of hemodynamic findings on surgical management in pediatric living donor liver transplantation (LT) was evaluated. Liver and systemic hemodynamics were studied prospectively in 52 children (median age, 1 year; 33 with biliary atresia [BA]). The hemodynamics of native liver were studied preoperatively by Doppler ultrasound and intraoperatively using invasive flowmetry. Portosystemic gradient was invasively measured. Systemic hemodynamics were studied preoperatively by Doppler transthoracic echocardiography and intraoperatively by using transpulmonary thermodilution. Hemodynamic parameters were correlated with Pediatric End-Stage Liver Disease (PELD) score and the histological degree of fibrosis (collagen proportionate area [CPA]). Cirrhosis was associated with a 60% reduction of pretransplant total liver flow (n = 46; median, 36 mL/minute/100 g of liver) compared with noncirrhotic livers (n = 6; median, 86 mL/minute/100 g; P = 0.002). Total blood flow into the native liver was negatively correlated with PELD (P < 0.001) and liver CPA (P = 0.005). Median portosystemic gradient was 14.5 mm Hg in children with cirrhosis and positively correlated with PELD (P < 0.001). Portal vein (PV) hypoplasia was observed mainly in children with BA (P = 0.02). Systemic hemodynamics were not altered in our children with cirrhosis. Twenty-one children met the intraoperative criteria for PV reconstruction using a portoplasty technique during the LT procedure and had a smaller PV diameter at pretransplant Doppler ultrasound (median = 3.4 mm; P < 0.001). Cirrhosis in children appears also as a hemodynamic disease of the liver, correlated with cirrhosis severity. Surgical technique for PV reconstruction during LT was adapted accordingly. Liver Transplantation 23 1440-1450 2017 AASLD.

The degree of spleen stiffness measured on acoustic radiation force impulse elastography predicts the severity of portal hypertension in patients with biliary atresia after portoenterostomy

BACKGROUND/PURPOSE

Acoustic radiation focus impulse (ARFI) elastography is a new method for assessing the degree of tissue stiffness. We herein evaluated the degree of spleen stiffness (SS) using ARFI elastography in patients with biliary atresia (BA) after Kasai portoenterostomy (KPE).

METHODS

We retrospectively collected the liver stiffness (LS) and SS values on ARFI elastography from 43 patients undergoing KPE between September 2010 and November 2013. We analyzed the correlations between these values and variables related to the severity of liver dysfunction and portal hypertension (PHT). The data were expressed as the standard deviation score (z-score) relative to the previously reported normal values for the patient's age.

RESULTS

The SS value was significantly associated with the spleen diameter and development of collateral vessels, in comparison to the LS value. Interestingly, there was a significant correlation between SS value and the portal vein (PV) diameter. Thirty patients (69.8%) consequently underwent LT; these patients showed higher SS values and smaller PV diameters than the patients monitored without LT.

CONCLUSIONS

The degree of SS measured on ARFI elastography can be used to predict the severity of PHT in BA patients after KPE.

Impact of pre-transplant liver hemodynamics and portal reconstruction techniques on post-transplant portal vein complications in pediatric liver transplantation: a retrospective analysis in 197 recipients

BACKGROUND AND OBJECTIVE

Portal vein (PV) complications are the most frequent vascular complications in pediatric liver transplant (LT). We hypothesized that pre-LT liver hemodynamic parameters and PV reconstruction technique could predict the risk of PV complications post-LT.

METHODS

Three hundred seventy-three children had a primary LT. A detailed ultrasound study of the pre-LT native liver hemodynamics was available in 198 cases, with details of PV anastomosis available for 197 of these: end-to-end anastomosis (n = 146, 74%), interposition vein graft technique (n = 28, 14%), or portoplasty (latero-lateral anastomosis of vein graft and recipient PV) (n = 23, 12%).

RESULTS

Overall 5-year patient survival rate was 90%. Among the 198 patients with pre-LT hemodynamic data, 79 (40%) had PV hypoplasia (diameter ≤4 mm), 64 (32%) had a pathological portal flow (nonhepatopetal flow), and 47 (24%) had an arterial resistance index (ARI) ≥1. Abnormal hemodynamics were mostly observed in biliary atresia (BA). Among these 3 parameters, only ARI ≥1 was significantly correlated with a higher rate of PV complications post-LT (P = 0.041). PV complication-free survival at 5 years were 91% for end-to-end anastomosis, 91% for portoplasty, and 62% for interposition vein graft technique (P = 0.002). At multivariate analysis, the use of an interposition vein graft was the only factor to be significantly associated with a higher rate of PV complications post-LT (P = 0.003).

CONCLUSIONS

PV hypoplasia with liver hemodynamic disturbances was mainly observed in BA. Hepatic ARI ≥1 might be a good predictor of PV complications post-LT. Latero-lateral portoplasty seemed to provide the best results when end-to-end anastomosis is not feasible.

The effect of hepatic portal dissection on the portal vein structure in biliary atresia

Superior mesenteric portograms were performed on 30 patients with biliary atresia (BA) at the time of initial portoenterostomy in 20, and at the stoma closure operation in 10. A withered-branch-shaped irregularity of the intrahepatic portal vein (PV) and collateral vessels were seen in 2 of 11 patients with portal pressures (PP) of 200 to 300 mmH2O; in 1 of 2 patients with PPs of over 300 mmH2O at the initial operation; and in 3 jaundice-free patients with PPs of 285, 320, and 305 mmH2O, respectively, at the stoma closure operation. Collaterals were the only abnormalities seen in two additional jaundice-free patients with PPs of 370 and 183 mmH2O, respectively. No anatomic changes in the extrahepatic PV at the porta hepatis were found on the portograms of either group of patients. Thus, we conclude that portal dissection itself does not affect the PV structure anatomically, a finding which has important implications in determining whether or not portoenterostomy adversely affects potential liver transplantation.

Endoscopic sclerotherapy in the management of esophageal varices in 61 children with biliary atresia

Sixty-one children who have survived 2.5 years or more after corrective surgery for biliary atresia were prospectively followed by endoscopy. Esophageal varices were detected in 41 patients (67%), 17 of whom (28%) had experienced episodes of variceal hemorrhage. Control of variceal bleeding was achieved by endoscopic injection sclerotherapy in all but one child who died from hemorrhage before the completion of treatment. Complications of the technique comprised episodes of bleeding before variceal obliteration (7), esophageal ulceration (5), and stricture (3). These resolved with conservative management and without long-term sequelae. During a mean follow-up period of 2.8 years after variceal obliteration, rebleeding from recurrent esophageal varices developed in only one child and responded to further sclerotherapy. These results are better than those following surgical procedures for portal hypertension in biliary atresia, and therefore endoscopic sclerotherapy is recommended as the treatment of choice.