Pulmonary complications of portal hypertension: The overlooked decompensation

Abstract

The systemic nature of cirrhosis and portal hypertension has long been recognized, and the amount of data characterizing the interplay between each system is becoming ever so complex. Lung involvement was among the first described associated entities in cirrhosis, with reports dating back to the late nineteenth century. However, it appears that throughout the years, interest in the pulmonary complications of portal hypertension has generally faded, especially in contrast to other decompensating events, as expertise in this field has primarily been concentrated in highly experienced tertiary care facilities and liver transplantation centers. Despite affecting up to 10%-15% of patients with advanced liver disease and having a proven prognostic impact, hepato-pulmonary syndrome, porto-pulmonary hypertension, and hepatic hydrothorax are frequently misdiagnosed, mistreated, or misinterpreted. This lack of precision might adversely impact patient care, referral to expert centers, and, ultimately, liver disease-related mortality and successful transplantation odds. The present minireview aims to increase awareness of the pulmonary complications of chronic liver disease by providing a brief overview of each of the three entities. The paper focuses on the essential theoretical aspects, addressing the most critical knowledge gaps on the one hand and, on the other hand, critically discussing one key issue for each complication.

Keywords: Advanced liver disease; Cirrhosis; Hepatic hydrothorax; Hepato-pulmonary syndrome; Portal hypertension; Porto-pulmonary hypertension.

Figure 1

Pathophysiology and diagnostic criteria of the hepatopulmonary syndrome. A-a: Alveolo-arterial; US: Ultrasonography.

Figure 2

Hemodynamic definition criteria for porto-pulmonary hypertension. HVPG: Hepatic venous pressure gradient; mPAP: Mean pulmonary artery pressure; PVR: Pulmonary vascular resistance; PAWP: Pulmonary artery wedged pressure.