Does Biliodigestive Anastomosis Have Any Effect on the Reversal of Hepatopulmonary Syndrome in a Biliary Cirrhosis Experimental Model?

Abstract

Background: Biliary cirrhosis is associated with hepatopulmonary syndrome (HPS), which is related to increased posttransplant morbidity and mortality.

Aims: This study aims to analyze the pathophysiology of biliary cirrhosis and the onset of HPS.

Methods: Twenty-one-day-old Wistar rats were subjected to common bile duct ligation and were allocated to two groups: group A (killed 2, 3, 4, 5, or 6 weeks after biliary obstruction) and group B (subjected to biliodigestive anastomosis 2, 3, 4, 5, or 6 weeks after the first procedure and killed 3 weeks later). At the killing, arterial blood was collected for the analyses, and samples from the liver and lungs were collected for histologic and molecular analyses. The gasometric parameters as well as the expression levels of ET-1, eNOS, and NOS genes in the lung tissue were evaluated.

Results: From a total of 42 blood samples, 15 showed hypoxemia (pO₂ < 85 mmHg) and 17 showed an increased oxygen gradient [p (A-a) O₂ > 18 mmHg]. The liver histology revealed increased ductular proliferation after common bile duct ligation, and reconstruction of bile flow promoted decreased ductular proliferation 5 and 6 weeks post-common bile duct ligation. Pulmonary alterations consisted of decreased parenchymal airspace and increased medial wall thickness. Biliary desobstruction promoted transitory improvements 5 weeks after biliary obstruction (increased parenchymal airspace and decreased MWT-p = 0.003 and p = 0.004, respectively) as well as increased endothelin expression levels (p = 0.009).

Conclusions: The present model showed lung tissue alterations promoted by biliary obstruction. The biliodigestive anastomosis had no clear direct effects on these alterations.

Keywords: Bile duct obstruction; Biliary cirrhosis; Biliary desobstruction; Cirrhosis reversibility; Experimental animal model; Hepatopulmonary syndrome.