Jae Ho Cho

Changes of the Renal Arteries Accordding to Various Embolic Materials

The transarterial embolization has been widely used to control bleeding. It has a variety of clinical utility; to reduce bleeding on the surgical field, to reduce the size of malignant tumor as a preopearative treatment, to treat arteriovenous malformation or arterial aneurysm as a curative method and to promote life quality of patient with diffuse or multiple hepatocellular carcinoma as a palliative treatment, etc. With the advance of modem technology, various embolic materials have been also developed. However, it has not been fully investigated of histopathologic changes of the embolized organs according to the embolic materials used. This study was undertaken to investigate the histopathologic changes of embolized renal artery in rabbit by various embolic materials, according to each embolic material and to time passed by after embolization. Of the 5 arteries embolized by ethylene vinyl alcohol copolymer(EVAL), one showed abscess formation in embolized kidney. The other 4 allowed to perform further pathologic study: within a week after embolization there was no any specific change in vessels, however, minimal endothelial hypertrophy was observed following 2 weeks of embolization. Of the 8 renal arteries embolized by N-buthyl-2-cyanoacrylate(Histoacryl), 4 showed total occlusion of the main renal arteries as well as renal infarction, which reflects the strong adhesiveness of Histoacryl to vascular wall. The other 4 showed fibrinoid degeneration in vascular wall within a week. However, further change was not observed thereafter. In all the 5 renal arteries embolized by polyvinyl alcohol(Ivalon), there were infiltration of inflammatory cells along the vessel walls, within one week, which represents vasculitis. They showed some fibrosis with appearance of giant cells in the vessel wall two weeks after embolization and also showed marked fibrosis of connective tissues surrounding vessels two months after embolization, respectively. The results suggest that EVAL is useful for the embolization of hypervascular lesion with limited arteriovenous fistula, Histoacryl for the curative treatment of the lesion with high blood flow or severe arteriovenous fistula, and Ivalan for palliative treatment of malignant tumor or arteriovenous malformation, respectively.

Advantades of the intravenous bolus CT scan in differentiation of hepatic masses

W e performed IV bolus CT scan in 40 patients with final diagnosis of various hepa tic m asses in order to evaluate hemodynamic changes and differentiating characters of the lesions. Preenhanced , early and late phase post enhanced , and delayed CT scans were obtained with rapid IV bolus injection of contrast m aterials and table sliding method for pertinen t scans. In hepa tom as , early enhanced CT scan directly showed hypervascula r change and active viable portion of the m ass and late phase CT scan showed capsular enhancemen t. In addition , extracapsular invasion and post-embolization recurrence were more easily visualized In hem angiomas , early and late enhancing types could be categorized according to the time of m aximal enhancem en t. In metastatic Iiver m alignancies and cholangiocarcinom as , specific findin gs were seen in early phase and delayed CT scans and not in conventional C T scan . In conclusion , IV bolus C T scan is a very useful CT method in demonstra ting the characteristic hem odynamic patterns and in differential diagnosis of the hepa tic m asses lndex Words: Liver, Computed tomography, 76 1. 1211 Liver , Primary malignant neoplasm , 761 .32 Liver, Metastatic m alignant neoplasm , 761. 33 Liver , Benign neoplasm , 76 1. 31