Embolization of Experimental Wide-Necked Aneurysms with Iodine-Containing Polyvinyl Alcohol Solubilized in a Low-Angiotoxicity Solvent
O. Dudecka,
O. Jordand,
K.T. Hoffmanna,
A.F. Okuducub,
I. Husmannc,
T. Kreuzer-Nagya,
K. Tesmera,
P. Podrabskya,
H. Bruhna,
J. Hilborne,
D.A. Rüfenachtf,
E. Doelkerd and
R. Felixa
a Department of Radiology, University of Geneva, Switzerland
b Department of Neuropathology, University of Geneva, Switzerland
c Department of General Surgery, University of Geneva, Switzerland
d Department of Charité, Campus Virchow Clinic, Berlin, Germany; School of Pharmacy, University of Geneva, Switzerland
e Department of Angström Laboratory, Polymer Chemistry, University of Uppsala, Sweden
f Department of Neuroradiology Section, University Hospital of Geneva, Switzerland
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Fig 1. Embolization of experimental wide-necked aneurysms with the liquid embolic I-PVA:
A, Digital subtraction carotid artery angiogram (DSA) of experimental aneurysm (swine 6, right common carotid artery).
B, Aneurysmography performed before embolization confirms blood flow-arrest while a compliant balloon bridging the aneurysm neck is inflated (arrow indicates tip of the microcatheter within the aneurysm cavity).
C, First cycle of polymer injection. I-PVA is injected within the first 2 minutes of a temporary carotid artery occlusion time of 5 minutes total. Note the good visibility of I-PVA, which accumulates at the tip of the microcatheter, under fluoroscopy.
D, Second cycle of polymer injection. I-PVA enlarges mainly around the microcatheter, gradually filling the aneurysm cavity.
E, Third cycle of polymer injection after which I-PVA appears to completely fill the aneurysm.
F, Immediate postembolization DSA demonstrates almost complete occlusion of the aneurysm with a small neck remnant next to the former microcatheter position (arrow).
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Fig 2. Follow-up investigations after 4 weeks.
A, Bicarotid trunk angiogram obtained 4 weeks after embolization reveals bilateral complete aneurysm occlusion with preserved parent artery patency.
B, Volume-rendered reconstruction of 16-row multisection CT angiogram (MSCTA). The polymer-filled aneurysms do not produce beam-hardening artifacts, so that morphology of the parent artery and that of the polymer cast could be evaluated concomitantly, frequently confirming angiographic findings.
C, Maximum intensity projection (MIP) of MSCTA displaying exclusively the right carotid artery for closer vessel evaluation. Note the separation between the cast and the carotid artery on axial sections suggesting the formation of a neointima layer (arrow, upper left hand corner).
D, Right carotid artery angiogram confirms MSCTA findings, but demonstrates this soft tissue interposition more clearly (arrow).
E, Axial gadolinium-enhanced T1-weighted 3D fast-spoiled gradient-echo imaging (FSPGR) allows for a detailed evaluation of the configuration of the polymer cast, demonstrating a smooth reconstruction of the arterial vessel wall (arrow).
F, 3D time-of-flight MR angiography shows preserved carotid artery patency; no intra-aneurysmal flow signals were observed.
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Fig 3. Gross and microscopic evaluation of resected aneurysms:
A, Macroscopic view of the aneurysm orifice from the arterial lumen. The former aneurysm neck is completely covered with a fibrous tissue layer.
B, Microscopic view of the carotid artery harboring the embolized aneurysm reveals a smooth transition from the arterial wall surface to the newly formed membrane (arrows), which consists of fibrous connective tissue (hematoxylin-eosin; original magnification, 20x). C, carotid artery wall; M, connective tissue membrane; S, suture; P, polymer inclusions.
C, Neointima formation consisting of fibroblasts covered by a single layer of endothelial cells (arrows). Note the disruption of the internal elastic lamina within the neointima (Elastica van Gieson; original magnification, 100x). C, carotid artery wall; M, connective tissue membrane.
D, Intra-aneurysmal inflammatory response consists mostly of lymphocytes and histiocytes (IR). Note numerous multinucleated foreign giant cells (GC) surrounding the eosinophilic embolic material (P) as well as many inflammatory cells within the polymer fragments (hematoxylin-eosin; original magnification, 100x).
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