Partition of calibrated tris-acryl gelatin microspheres in the arterial vasculature of embolized nasopharyngeal angiofibromas and paragangliomas
Résumé
PURPOSE:
To determine the location of calibrated tris-acryl gelatin microspheres (TGMs) in the arterial vasculature of nasopharyngeal angiofibromas (NAFs) and paragangliomas (PGs).
MATERIALS AND METHODS:
Forty-nine specimens (25 PGs and 24 NAFs) treated operatively after embolization with TGMs of various sizes (100–300 μm to 900–1200 μm) were stained with hematoxylin and eosin saffron and analyzed at an objective magnification of 10 or 20 with a micrometric eyepiece (magnification, ×12.5). The diameter of occluded vessels, their localization (intraor 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-μm TGMs versus 500–700-μm TGMs (P = .0006) as well as 300–500-μm TGMs versus 500–700-μm TGMs (P = .0001).
CONCLUSIONS:
The size of the vessels occluded by TGMs and their intraor 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.
