Effectiveness of endovascular embolization with a collagen-based embolic agent (Marsembol) in an animal model

To investigate in a porcine experimental model the effectiveness, tissue penetration, and histologic impact of renal artery embolization with a collagen-based nonadhesive embolic agent, marsembol.

Fifteen pigs underwent embolization of one interlobular artery of the renal artery with collagen-resorcinol gel emulsified with Lipiodol and further polymerized with glutaraldehyde-formaldehyde mixture. Angiograms were obtained before, during, and after the procedure. Animals were euthanized at day 0 (n = 3), 1 week (n = 3), or 3 months (n = 7), and flat-panel three-dimensional rotational radiologic images of the kidneys were obtained. Arterial, medullary, and cortical samples were taken for histologic and scanning electron microscopic investigations.

Fifteen interlobular renal arteries were successfully embolized by delivering 1.7 mL + or - 0.2 of the embolic agent. All the embolized arteries remained occluded at 3 months, leading to a major atrophy of the embolized portions of the kidneys. Imaging and histologic findings show that the embolic agent provided a distal vessel occlusion and entirely filled the lumen of the arteries up to the glomerular tufts. The homogeneous plug formed by the embolic agent induces very few inflammatory responses. The regenerative tubular processes were arrested at 3 months.

The collagen-based embolic agent described here has the properties required to perform embolization. These specific properties lead to very distal vessel embolization. The embolic agent is effective at 3 months in renal embolization.