EMBOLIZATION WITH CELLULOSE POROUS BEADS .1. AN EXPERIMENTAL-STUDY

PURPOSE: To study the possibility of using cellulose porous beads (CPB s) as a solid embolic material for the permanent occlusion of blood ve ssels, METHODS: Unilateral renal arteries of 12 adult mongrel dogs wer e embolized with CPBs. Selective renal angiograms were obtained immedi ately, 1 hour, 4 weeks, and 12 weeks after the embolization. The dogs were killed 1 hour (n=4), 4 weeks (n=4), or 12 weeks (n=4) after the p rocedure. The kidneys were removed en bloc and examined histologically . RESULTS: The CPBs were easily injected through a microcatheter, were readily controlled with radiodensity, and did not adhere to the cathe ter. Renal angiograms obtained after embolization disclosed complete o cclusion of the renal artery. Microscopically, the CPBs traveled to ve ssels with approximately the same diameter size. Larger vessels were o ccluded by aggregations of particles that left no open spaces. We foun d no disruption of the vessel wall, no evidence of perivascular hemorr hage, and no inflammatory changes of the vessel wall or the surroundin g tissues. CONCLUSION: The CPBs were easy to use; they reached distal sites and produced a homogeneous and permanent occlusion without speci fic inflammatory changes. The good results of this experimental study led to a clinical trial of CPBs.