Imaging techniques and histology in the evaluation of liver fibrosis in hepatosplenic schistosomiasis mansoni in Brazil: a comparative study

Abstract

Few publications have compared ultrasound (US) to histology in diagnosing schistosomiasis-induced liver fibrosis (LF); none has used magnetic resonance (MR). The aim of this study was to evaluate schistosomal LF using these three methods. Fourteen patients with hepatosplenic schistosomiasis admitted to hospital for surgical treatment of variceal bleeding were investigated. They were submitted to upper digestive endoscopy, US, MR and wedge liver biopsy. The World Health Organization protocol for US in schistosomiasis was used. Hepatic fibrosis was classified as absent, slight, moderate or intense. Histology and MR confirmed Symmers' fibrosis in all cases. US failed to detect it in one patient. Moderate agreement was found comparing US to MR; poor agreement was found when US or MR were compared to histology. Re-classifying LF as only slight or intense created moderate agreement between imaging techniques and histology. Histomorphometry did not separate slight from intense LF. Two patients with advanced hepatosplenic schistosomiasis presented slight LF. Our data suggest that the presence of the characteristic periportal fibrosis, diagnosed by US, MR or histology, associated with a sign of portal hypertension, defines the severity of the disease. We conclude that imaging techniques are reliable to define the presence of LF but fail in grading its intensity

Revisiting the concept of hepatosplenic schistosomiasis and its challenges using traditional and new tools

“…Our data suggest that the intensity of LF evaluated by imaging techniques or histology is not related, in a signifi cant number of patients, to portal hypertension, and severe portal hypertension has been reported in patients with minimal liver fi brosis 13,38 . The World Health Organization (WHO) grading of liver fi brosis by US should be reevaluated and used carefully in the defi nition of the severity of hepatosplenic schistosomiasis.…”

“…It uses strong magnetic fi elds and non-ionizing radiation in the radio frequency range, in contrast to CT scans and traditional X-rays, which both use ionizing radiation. Contrast agents may be injected intravenously to enhance the appearance of blood vessels, tumors or infl ammation [36][37][38][39][40][41][42][43] . …”

“…Some authors criticize the use of wedge liver biopsy because the fragments come from the periphery of the organ and fi brosis is not expected to be uniformly distributed 19 . Nevertheless, Dusek et al 8 stated that a large enough specimen for histological assessment is obtainable only by surgical wedge biopsy and that the specimens are often suffi cient to make an accurate diagnosis 7,38 .…”

“…The World Health Organization (WHO) grading of liver fi brosis by US should be reevaluated and used carefully in the defi nition of the severity of hepatosplenic schistosomiasis. Papers published using the WHO classifi cation should also be revised 37,38,41 . The characteristic periportal fi brosis (diagnosed by US, MRI or histology) associated with evidence of portal hypertension (large spleen, esophageal varices and collateral vessels) should be suffi cient to defi ne disease severity and indicate surgical intervention, as necessary.…”

Treatment and education reduce the severity of schistosomiasis periportal fibrosis

“…It has been shown that specifi c treatment for S. mansoni can contribute to decreasing infection levels and improving clinical conditions such as hepatosplenomegaly and PPF [15][16][17] . As a result, the regression of PPF may prevent the emergence of portal hypertension, highlighting the importance of PPF diagnosis by obtaining accurate methods for monitoring this disease 18 .…”