Partition of calibrated tris-acryl gelatin microspheres in the arterial vasculature of embolized nasopharyngeal angiofibromas and paragangliomas.
OBJECTIVE
To determine the location of calibrated tris-acryl gelatin microspheres (TGMs) in the arterial vasculature of nasopharyngeal angiofibromas (NAFs) and paragangliomas (PGs).


METHODS
Forty-nine specimens (25 PGs and 24 NAFs) treated operatively after embolization with TGMs of various sizes (100-300 microm to 900-1200 microm) were stained with hematoxylin and eosin saffron and analyzed at an objective magnification of 10 or 20 with a micrometric eyepiece (magnification, x12.5). The diameter of occluded vessels, their localization (intra- or extratumoral), and the number and diameter of TGMs they contained were determined.


RESULTS
Embolized vessels (N = 1125) were measured: 440 in PGs and 685 in NAFs. Vessels were 89% intratumoral and 11% extratumoral. The diameter of the occluded vessels increased significantly with the size range of TGMs used for embolization for each tumor type (P < .0001). Intratumoral occluded vessels were significantly smaller than extratumoral vessels (P < .0001). Distribution of TGMs within the vascular network (intratumoral or extratumoral location) were similar for NAFs and PGs. The intratumoral and extratumoral dissemination of TGMs was different when comparing 100-300-microm TGMs versus 500-700-microm TGMs (P = .0006) as well as 300-500-microm TGMs versus 500-700-microm TGMs (P = .0001).


CONCLUSIONS
The size of the vessels occluded by TGMs and their intra- or extratumoral location directly depend on the size of the injected TGMs. The vessels located inside the tumors were smaller than those located outside the tumors. A threshold for the intratumoral penetration of TGMs in the vasculature can be proposed from these data. There was no evidence of different behavior of TGMs in NAFs versus PGs.
Laurent
Alexandre
A
Department of Interventional Neuroradiology, Hôpital Lariboisière, AP-HP, 2 rue Ambroise Paré, 75475 Paris Cedex 10, France. alex.laurent@lrb.ap-hop-paris.fr
Wassef
Michel
M
Chapot
Rene
R
Wang
Yabing
Y
Houdart
Emmanuel
E
Feng
Ling
L
Tran Ba Huy
Patrice
P
Merland
Jean-Jacques
JJ
D000180:Acrylic Resins / Q000737:chemistry / Q000627:therapeutic use*; D000293:Adolescent; D000328:Adult; D000368:Aged; D018322:Angiofibroma / Q000098:blood supply* / Q000628:therapy; D000792:Angiography; D001158:Arteries / Q000473:pathology; D002648:Child; D004396:Coloring Agents; D004621:Embolization, Therapeutic / Q000379:methods*; D005456:Fluorescent Dyes; D005780:Gelatin / Q000737:chemistry / Q000627:therapeutic use*; D006801:Humans; D008863:Microspheres; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000098:blood supply* / Q000628:therapy; D010235:Paraganglioma / Q000098:blood supply* / Q000628:therapy; D012189:Retrospective Studies; D013499:Surface Properties
D000180:Acrylic Resins; D004396:Coloring Agents; D005456:Fluorescent Dyes; C496735:trisacryl gelatin microspheres; D005780:Gelatin