The Value Of Contrast Sonography In The Splenic Microwave Quantitative Ablation And The Clinical Effects On Hypersplenism And Spleen Immune Function

Part I The value of contrast sonography in the splenic microwave ablation therapy for secondary splenomegaly andhypersplenismObjective To assess the value of contrast sonography in the splenic microwave ablation therapy for secondary splenomegaly and hypersplenism. Materials and Methods Thirteen healthy mongrel dogs weighing 15-17 kg were used in this study. Congestive splenomegaly was induced by ligation of the main splenic vein (LSV) at the confluent to portal vein and its collateral branches at the hilum of the spleen. At the end of 3rd week of LSV, splenic microwave ablation was performed in these animals. Two-six needles were inserted into the splenic parenchyma sequentially and the microwave power was set at 60W 300s, 50W 360s and 40W 450s respectively. Gray-scale contrast-enhanced ultrasonography and CDFI were performed immediately after the therapy and at 1, 4, 8 weeks posttherapy respectively . The microbubble US contrast agent that we used in this study was SonoVue? Gray-scale real-time contrast-enhanced sonography was performed after injection of SonoVue?(BR1, Bracco, Milan, Italy) . DU8 scanner ( Esaote Technos) with LA532 E 8-3 high frequency transducer was used in this study. When the parameters such as time-compensated gain, depth, focus were optimized, they were held constant for each examination. The mechanical index was 0.089. The dogs were sacrificed after the sonography. Specimen of spleens were obtained to make routine histopathological studies. Results (1) SonoVue?combined withgray-scale contrast-enhanced sonography could be used to display the margin of the necrotic region in the spleen. There was no difference between the dimensions of the necrotic region displayed by contrast sonography and those by splenic specimen. (2) The sensitivity and specificity of SonoVue?to assess the uncomplete necrosis in spleen were 90% and 100% respectively. (3) All the 10 ablated regions immediately after therapy were uncomplete necrosis and microscopically some residual white pulps and its central artery could be seen in the necrotic region. 20 ablated regions at 1, 4, 8 weeks posttherapy respectively were completely necrotic and fibrotic encapsule was formed around the necrotic area. Conclusions Gray-scale contrast-enhanced sonography could be used to evaluate the degree of necrosis of the ablated lesion and to display the margin of ablated lesion in the spleen.