Hepatopulmonary syndrome in patients with Schistosoma mansoni periportal fibrosis

Abstract

Hepatopulmonary syndrome (HPS) is characterized by the presence of liver disease, arterial hypoxemia and intrapulmonary vascular dilatation (IPVD). IPVD includes diffused or localized dilated pulmonary capillaries and, less commonly, pleural and pulmonary arteriovenous communications. The aim of the present study was to investigate the occurrence of HPS in patients with Schistosoma mansoni periportal fibrosis in treatment at a university hospital in northeastern Brazil.

Patients and methods: Eighty-four patients were enrolled in the study between April and July 2007 and underwent arterial blood gas analysis. Patients with an alveolar-arterial oxygen gradient (DA-aO(2)) > or = 15 mmHg were submitted to contrast-enhanced transthoracic echocardiogram (CE-TTE) with saline microbubbles. The diagnostic criterion for HPS was DA-aO(2) > or = 15 mmHg associated to IPVD, as identified through CE-TTE. Patients with HPS underwent contrast-enhanced 16-channel multidetector-row computed tomography (MDCT) of the thorax.

Results: Twenty-two patients (26.19%) had DA-aO(2) > or = 15 mmHg (mean value=20.86+/-7.91). CE-TTE was positive for IPVD in five of the 22 patients with DA-aO(2) > or = 15 mmHg and all these patients had hepatosplenic disease, revealing a 6% prevalence of HPS (CI: 1.96-13.35) in the overall population of 84 patients, with a 10.2% prevalence in the group with hepatosplenic disease. The following were the 16-channel MDCT findings in these five patients: dilated peripheral pulmonary vasculature (100%); ratio of segmental arterial diameter to adjacent bronchial diameter equal to or greater than 2:1 (100%); higher number of visible terminal vessel branches in lung dependent regions (40%); and micronodules associated with subpleural surface centrilobular vessels (40%). No patient had evidence of arteriovenous fistula. These findings reveal that HPS occurs (usually in a mild form) in patients with Schistosoma mansoni periportal fibrosis and portal hypertension seems to be an important factor related to the occurrence of HPS in such cases.