Aspectos ultrassonográficos e hemodinâmicos da esquistossomose mansônica: avaliação pela ultrassonografia Doppler em áreas endêmicas

Increased Hepatic Arterial Blood Flow Measured by Hepatic Perfusion Index in Hepatosplenic Schistosomiasis: New Concepts for an Old Disease

BACKGROUND

Portal vein obstructive lesions associated with hypertrophy of the hepatic artery territory are observed in Schistosoma mansoni schistosomiasis. Liver perfusion scintigraphy is a method used for evaluation of hepatic perfusion changes in liver diseases. It has been suggested that, like in cirrhosis, where compensatory increase in perfusion through the hepatic artery is documented, perfusion changes occur in hepatosplenic schistosomiasis (HSS).

AIMS

This study aims to determine changes in liver hemodynamics using hepatic perfusion scintigraphy and correlate them with clinical and laboratory variables and ultrasound findings in HSS.

METHODS

Nineteen patients with schistosomiasis underwent ultrasound evaluation of degree of liver fibrosis, splenic length, and splenic and portal vein diameter, digestive endoscopy, and quantification of platelets. Subsequently, perfusion scintigraphy with measurement of hepatic perfusion index (HPI) was performed.

RESULTS

It was observed that patients with hepatosplenic schistosomiasis had significantly higher HPI compared with normal individuals (p = 0.0029) and that this increase correlated with splenic length (p = 0.038) and diameter of esophageal varices (p = 0.0060). Angioscintigraphy showed high accuracy for predicting presence of large esophageal varices.

CONCLUSIONS

Angioscintigraphy could show that patients with HSS had increased HPI, featuring greater liver "arterialization," as previously described for cirrhotic patients. Correlations were also observed between HPI and longitudinal splenic length, caliber of esophageal varices, caliber of portal vein, and blood platelet count. Angioscintigraphy is a promising technique for evaluation of hepatosplenic schistosomiasis.

The WHO ultrasonography protocol for assessing hepatic morbidity due to Schistosoma mansoni. Acceptance and evolution over 12 years

The aim of this study is to review the worldwide acceptance of the World Health Organization (WHO) ultrasound protocol for assessing hepatosplenic morbidity due to Schistosoma mansoni since its publication in 2000. A PubMed literature research using the keywords "schistosomiasis and ultrasound," "schistosomiasis and ultrasonography," and "S. mansoni and ultrasound" from 2001 to 2012 was performed. Case reports, reviews, reports on abnormalities due to parasites other than S. mansoni, organ involvement other than the human liver, and reports where ultrasound method was not described were excluded. Six studies were retrieved from other Brazilian sources. Sixty studies on 37,424 patients from 15 countries were analyzed. The WHO protocol was applied with increasing frequency from 43.75% in the years 2001 to 2004 to 84.61% in 2009 to 2012. Results obtained using the pictorial image pattern approach of the protocol are reported in 38/41 studies, whereas measurements of portal branch walls were applied in 19/41 and results reported in 2/41 studies only. The practical usefulness of the pictorial approach of the WHO protocol is confirmed by its wide acceptance. This approach alone proved satisfactory in terms of reproducibility, assessment of evolution of pathology, and comparability between different settings. The measurements of portal branches, also part of the protocol, may be omitted without losing relevant information since results obtained by these measurements are nonspecific. This would save resources by reducing the time required for each examination. It is also more feasible for examiners who are not specialized in medical imaging. As with all protocols, incipient liver fibrosis is difficult to distinguish from normal ultrasound findings of the liver. The ability of this protocol to predict complications in severe cases should be further evaluated in a higher number of patients.

Aspectos ultrassonográficos associados à morbidade de formas clínicas crônicas de esquistossomose mansônica, utilizando-se protocolo proposto pela Organização Mundial da Saúde

OBJETIVO: Avaliar aspectos ultrassonográficos associados à morbidade em pacientes com formas clínicas crônicas de esquistossomose mansônica, utilizando-se protocolo proposto pela Organização Mundial da Saúde (OMS). MATERIAIS E MÉTODOS: Foram avaliadas duas populações distintas: a) área endêmica e b) institucional terciária, com histopatológico confirmando fibrose. Critérios de inclusão: diagnóstico confirmado por parasitológico de fezes para Schistosoma mansoni (método Kato-Katz). Critérios de exclusão: sorologia positiva para HIV, HTLV-1, VHB ou VHC. Foi utilizado protocolo ultrassonográfico de Niamey, proposto pela OMS. RESULTADOS: Avaliando-se isoladamente as medidas dos espaços periportais, estas se mostraram sem alterações em 21% dos indivíduos com doença avançada da instituição terciária. Utilizando-se todos os parâmetros do protocolo, 100% dos indivíduos da instituição terciária, com forma grave da doença, apresentaram fibrose periportal avançada. Em pacientes hepatoesplênicos da área endêmica não se identificou fibrose à ultrassonografia. CONCLUSÃO: O protocolo ultrassonográfico proposto pela OMS detecta fibrose periportal avançada nos pacientes com forma grave da doença, com maior sensibilidade do que a medida do espaço periportal isoladamente. A complexidade de identificação das fases iniciais da fibrose periportal, em áreas endêmicas, pela ultrassonografia, pode suscitar o campo da complementação diagnóstica e a continuidade do aprimoramento dos protocolos ultrassonográficos nestas áreas.