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

Intrahepatic portal veins were reconstructed from serial histologic sections of surgical liver specimens from patients with biliary atresia to explain the pathogenesis of portal hypertension, an important late postoperative complication of this disease. It was found that abnormal intrahepatic vasculature was already notable in an evidently reduced number of portal veins in the second month of age, and this was considered responsible for causing presinusoidal block that gave rise to the elevated resistance to intrahepatic portal flow. Reconstruction also revealed that restoration of ordinary portal structure was expectable if, after successful surgery, a patient was sufficiently protected from cholangitis and there was much room for portal veins to grow without being impeded by inflammatory and/or scarring processes. In contrast, the patient whose condition was complicated by cholangitis was shown to acquire a markedly hypoplastic portal system with apparently reduced vascularity.