Improving Our Understanding of Portopulmonary Hypertension
Abstract
Pulmonary arterial hypertension (PAH) is characterized by elevated pulmonary artery pressure and pulmonary vascular resistance, right heart failure, exercise limitation, and an increased risk of death. Histopathologic examination reveals intimal proliferation, medial hypertrophy, and adventitial fibrosis in the small muscular pulmonary arteries. Plexiform lesions and in situ thrombosis are also seen. Most commonly idiopathic, PAH may also be associated with portal hypertension, termed portopulmonary hypertension (PoPH). Previous studies have shown a prevalence of histopathologic changes of PAH of 0.61% in autopsies of patients with cirrhosis, and PoPH was the third most common form of PAH in a population-based epidemiologic study in France. Recent cohort studies showed that the prevalence of POPH in patients presenting for liver transplant evaluation is between 5 and 6%. Patients with POPH have an increased risk of death, even with specific PAH treatment. In many cases, POPH greatly complicates or precludes liver transplantation, significantly affecting the course of hepatic failure in these patients. The etiology of PAH in patients with portal hypertension (characterized by systemic vasodilatation) is unclear. We have shown that female sex and autoimmune etiology of liver disease are associated with the risk of POPH. Although germline mutations in the gene that codes for bone morphogenetic protein receptor type II(BMPR2) have been associated with idiopathic and familial forms of PAH, they have not been found in patients with POPH.
In this thesis, a step-by-step approach is proposed to advance our understanding of POPH, and the outcome of this project is to provide a comprehensive systemic review of POPH, diagnosis, evaluation and management. In addition, we want to understand the leading cause of mortality in patients with POPH and why liver transplant is so underutilized.
Subject
Pulmonary arterial HypertensionPortopulmonary Hypertension
Liver Cirrhosis
Portal Hypertension
Citation
Sahay, Sandeep (2022). Improving Our Understanding of Portopulmonary Hypertension. Master's thesis, Texas A&M University. Available electronically from https : / /hdl .handle .net /1969 .1 /197093.