Pulmonary shunts in severe hepatosplenic schistosomiasis: Diagnosis by contrast echocardiography and their relationship with abdominal ultrasound findings.

Liana Gonçalves-Macedo,Edmundo Pessoa Lopes,Carlos Feitosa Luna,Brivaldo Markman-Filho,Ana Lucia Coutinho Domingues,Mônica Moraes De Chaves Becker,Vitor Gomes Mota,Michael H Hsieh

doi:10.1371/journal.pntd.0005417

Liana Gonçalves-Macedo, Edmundo Pessoa Lopes + Show 6 more

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https://doi.org/10.1371/journal.pntd.0005417

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Abstract

BackgroundSchistosomiasis is endemic to several parts of the world. Among the species that affect humans, Schistosoma mansoni is one of the most common causes of illness. In regions where schistosomiasis mansoni is endemic, reinfection is responsible for the emergence of hepatosplenic schistosomiasis (HSS) with portal hypertension in about 10% of infected individuals. Regardless of its etiology, portal hypertension may bring about the formation of arteriovenous fistulas and pulmonary vascular dilation, thus constituting a pulmonary shunt and its presence has been associated with the occurrence of neurological complications. The objective of this study was to identify pulmonary shunt using TTCE in patients with HSS and esophageal varices, and to compare the abdominal ultrasound and endoscopy findings among patients with and without pulmonary shunt.Methodology/Principal findingsIn this case series, a total of 461 patients with schistosomiasis mansoni were prospectively evaluated using abdominal ultrasound and endoscopy and 71 presented with HSS with esophageal varices. Fifty seven patients remained in the final analysis. The mean age of the patients was 55 ± 14 years, and 65% were female. Pulmonary shunts were observed in 19 (33.3%) patients. On comparing the groups with and without pulmonary shunt, no significant differences were observed in relation to the abdominal ultrasound and endoscopic findings. When comparing the two subgroups with pulmonary shunts (grade 1 vs grades 2 and 3), it was observed that the subgroup with shunt grades 2 and 3 presented with a significantly higher frequency of an enlarged splenic vein diameter (>0.9 cm), and an advanced pattern of periportal hepatic fibrosis (P = 0.041 and P = 0.005, respectively). None of the patients with pulmonary shunts had severe neurological complications.Conclusions/SignificanceOur findings suggest that in HSS with esophageal varices the pulmonary shunts may be present in higher grades and that in this condition it was associated with ultrasound findings compatible with advanced HSS.

Highlights

It is estimated that more than 200 million people in the world are infected with Schistosoma and more than 700 million remain at risk of infection, according to World Health Organiztion reports [1, 2]
Portal hypertension may promotes an imbalance in the hepatic production of vasoactive substances, which may act on the lungs promoting the formation of arteriovenous fistulas and pulmonary vascular dilation, a condition that is called a pulmonary shunt
When the pulmonary shunt is of higher grades, small thrombus or septic emboli that would normally be filtered through the pulmonary capillaries reach the left heart and the systemic circulation, which can lead to neurological complications

Summary

Introduction

It is estimated that more than 200 million people in the world are infected with Schistosoma and more than 700 million remain at risk of infection, according to World Health Organiztion reports [1, 2]. In Brazil, Schistosoma mansoni infection affects all of the Northeastern states and parts of the North, South, Southeast, and Mid-West, and it is endemic in nine states [4, 5]. In these regions, reinfection is frequent and around 10% of the infected individuals develop severe forms of the disease, such as hepatosplenic schistosomiasis (HSS), while in hospital-based samples this percentage may reach higher values [6]. Regardless of the etiology, an imbalance in the hepatic production of angiogenic and vasoactive substances, coupled with a possible genetic predisposition, promotes the formation of pulmonary vascular dilations and pulmonary arteriovenous fistulas. The objective of this study was to identify pulmonary shunt using TTCE in patients with HSS and esophageal varices, and to compare the abdominal ultrasound and endoscopy findings among patients with and without pulmonary shunt

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