ABC | Volume 113, Nº5, November 2019

Original Article Gouveta et al. cTEE in pulmonary artery dilation in HSS Arq Bras Cardiol. 2019; 113(5):915-922 No statistically significant difference was found in A-aO 2 between patients with and without IPVD, which highlights the role of cTEE in detecting subclinical disease. On the other hand, three patients with hypoxemia or increased A-aO 2 showed negative microbubble test by both echocardiographic tests. This may result from the type of contrast (saline solution), the injection technique or the size of the microbubbles injected. Although the microbubble size varied from 24 to180 µ, bubbles greater than 60 µ are more echogenic and possibly more difficult to pass through the capillary bed, even when it is dilated, resulting in a weaker signal. 12 In addition, the dissociation between the echocardiographic findings and results of the arterial blood gas analysis with respect to IPVD detection reflects the lability of gas exchange; the tests were not performed simultaneously, and hence temporal and dynamic changes of echocardiographic and gas exchange parameters may have occurred. Differences in PaO 2 , SatO 2 , PaCO 2 between the subgroups of patients with and without IPVD remain uncertain. Recent studies have suggested that IPVD are precursor or associated diseases of portopulmonary hypertension in patients with cirrhosis and schistosomiasis, 22,23 and that may be associated with decreased survival. 22 In cirrhotics, the presence of IPVDworsens the prognosis of portopulmonary hypertension, contributes to an earlier indication of liver transplantation, and increases the risk of mortality after transplantation in patients with increased hypoxemia. 24,25 However, the prognosis of IPVD in HSS is unknown, and IPVD are present in patients with no clinical or respiratory changes. Further studies are needed to establish the course of this disease. Safety Similar to other studies on patients with cirrhosis and portal hypertension, 11,25 cTEE was performed without complications in all HSS patients. The probe was safely inserted until the distal third of the esophagus and through the esophageal hiatus for acquisition of transgastric views even in the presence of recent bleeding after sclerotherapy. Limitations One limitation of the present study was the relatively small sample size. However, this is compatible with the profile of the disease in Brazil, whose incidence has been decreasing over the last years. This has been particularly evident in our university hospital which is located away from the endemic zones of the disease. The low prevalence of HSS in our small sample of patients made it difficult to demonstrate an association of the IPVD with the severity of hypoxemia and increase in A-aO 2 . Another limitation was the fact that the manual agitation of the saline solution produced microbubbles of different sizes, making it impossible to standardize their echogenicity, which would allow higher uniformity of the results. Clinical implications Our findings showed that a negative cTTE does not exclude the presence of cTEE. Therefore, in case of clinical suspicion, cTEE would be indicated to confirm the diagnosis of IPVD in this study group. The clinical relevance and the prognosis of vascular changes in HSS should be determined in future longitudinal studies. Conclusions In patients with HPS and relatively preserved liver function, cTEE was superior to cTTE in detecting IPVD, especially in its earlier stages. The transesophageal method was safe in these patients, most of them with previous sclerotherapy of esophageal varices and without recent bleeding. Finally, PFO, which was diagnosed in these patients, may be a confounding factor for the diagnosis of IPVD at cTTE. Author contributions Conception and design of the research and Writing of the manuscript: Gouvea A, Campos Filho O; Acquisition of data: Gouvea A, Arakaki JSO, Brant P; Analysis and interpretation of the data: Gouvea A, Fischer CH, Arakaki JSO, Mancuso FJ; Statistical analysis: Mancuso FJ, Campos Filho O; Critical revision of the manuscript for intellectual content: Gouvea A, Campos Filho O, Fischer CH, Arakaki JSO, Moisés VA, Campos Filho O. Potential Conflict of Interest No potential conflict of interest relevant to this article was reported. Sources of Funding There were no external funding sources for this study. Study Association This article is part of the thesis ofmaster submittedbyAparecida de Gouvea, from Universidade Federal de São Paulo - UNIFESP. Ethics approval and consent to participate This study was approved by the Ethics Committee of the Universidade Federal de São Paulo under the protocol number 38476. All the procedures in this study were in accordance with the 1975 Helsinki Declaration, updated in 2013. Informed consent was obtained from all participants included in the study. 920