Computer-assisted Quantification of Occlusion and Coil Densities on Angiographic and Histological Images of Experimental Aneurysms

Abstract

Computer-assisted DSA evaluation, delivering more precise values than subjectively estimated occlusion, may be a useful tool for follow-up studies. Comparing computer-assisted angiographic with histometrical occlusion demonstrates limits of DSA in displaying the real morphology of coil-embolized aneurysms. The clinically postulated correlation of OR and coil densities was statistically corroborated.

Computerized Assessment of Angiographic Occlusion Rate and Coil Density in Embolized Human Cerebral Aneurysms

“…In experimental aneurysms, the theoretic benefits of computerized angiographic occlusion rating have already been shown. 14 Comparable with the findings of the above-cited experimental study, also in the present human aneurysmal series, 12 of 14 aneurysms showed lower computerized OR values compared with subjective angiographic estimations. Besides several methodologic factors listed in the limitation section below, a major reason for this tendency to lower computerized angiographic OR values seems to be the higher-resolution power of the computerized gray value definition of the contrast medium in the parent arteries.…”

“…In our study, this validation was aimed by the comparison of the new computerized angiographic methods with the reference of corresponding histologic ground sections of the aneurysms, displaying the intra-aneurysmal morphologic detail with the highest available resolution power for morphometric quantification. [13][14][15]22 The comparison of computerized and histometric occlusion rates in the present series did not result in a statistically significant difference (P ϭ .2163) and showed, indeed, a very good correlation (r ϭ 0.799; P Ͻ .001) of computerized angiographic occlusion rating with good statistical power, despite the small sample size of 14 aneurysms.…”

“…[13][14][15]22 Ground-section planes were selected to show a representative overview of the aneurysmal occlusion focusing on the neck plane, together with the length axis of the aneurysm in accordance with the respective DSA projections. For every aneurysm, histomorphologic structures were outlined on digitized calibrated images from 2 to 4 surface-stained (Sanderson Rapid Bone Stain solution (SURGIPATH Medical, Richmond, Va) ground sections.…”

Improved Microsurgical Creation of Venous Pouch Arterial Bifurcation Aneurysms in Rabbits

“…2 Thus, experimental animal studies are crucial to test new and better endovascular devices, to improve long-term aneurysm occlusion. [3][4][5] The choice of the model is essential for the comparability of experimental findings with human conditions. 6 In a comparison of the currently used animal models in rats, rabbits, canines, and swine, [7][8][9] the rabbit model showed advantageous comparability with the human coagulation system and the best cost-effectiveness.…”

“…10 However, it has already been shown that the foreign body response to the monofilament sutures around the anastomosis is only benign and that this chronic inflammatory reaction to nonresorbable sutures is locally confined to the outer parts of the respective vessel walls. 5,22 What is more, the aneurysm wall in the venous pouch arterial bifurcation model consists of an unaltered vein transplant with just a few elastic membranes. These features can also be seen in human intracranial aneurysm walls.…”