Embolização pré operatória de tumores renais com microparticulas esféricas de tecnologia nacional. (Spherus®-First line Brasil)

Abstract

Os autores relatam pela primeira vez utilização de uma nova partícula para embolização, constituída de um núcleo de acetato de polivinil revestido por polivinil-álcool, de forma esférica (Spherus®-First Line Brasil), como preparo pré-operatório em três pacientes portadores de neoplasia renal, na intenção de diminuir o tamanho do tumor e prevenir complicações hemorrágicas durante o ato operatório. Estas novas partículas foram projetadas e elaboradas nos laboratórios da COPPE/UFRJ. A embolização intra-arterial pré-operatória com estas novas partículas ocasionou acentuada isquemia em todo o tecido tumoral facilitando o procedimento cirúrgico.

Tratamento endovascular de angiomiolipoma renal por embolização arterial seletiva

“…A palpable abdominal mass 6,7,12 is found in up to 53% of the cases, 7 and anemia, 6,7 in 21% 7 . Retroperitoneal bleeding [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] or macroscopic hematuria 1,2,6,10,11 may also occur. Large tumors may affect other organs and cause anorexia 1,10 .…”

“…Angiograms show anomalous vascularization and the formation of new vessels and microaneurysms 2,4,7,9,11,15 . Vessels are more susceptible to aneurysms and rupture because their walls have few normal elastic fibers, 1,2,4,7,13 and their muscle layer is replaced with dense fibers, 2 which explains why the tumor may hemorrhage easily 1,2,4,6,7,11,15,17 .…”

“…The criteria for intervention are: diameter greater than 4 cm (3.5 cm for some authors) 1-3,5,6,8,9,10,16 and pain ,1,4,6,7,11,15-17 as in the case described here. Other indications are active hemorrhage, [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] changes in tumor characteristics, 2-4 multiple RAML, bilateral or unilateral if in a single kidney, 2 and patients with TSC 4,6 .…”

“…Embolization of these lesions was described over 20 years ago 4 by Lalli et al 17 Currently, RAML are obstructed. The lack of particle homogeneity may also lead to inadequate penetration of the agent into the most distal points of the tumor vessels.…”

Adsorption of BSA (Bovine Serum Albuminum) and lysozyme on poly(vinyl acetate) particles

“…Embolization techniques have been used to treat several clinical problems, including treatment of malignant tumors and arteriovenous malformation [16][17][18][19][20] . Transarterial chemoembolization is a medical technique that combines the application of a drug with an embolic agent, leading to local chemical and physical actions during treatment [21][22][23][24] .…”