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.