title: Observation of intravascular changes of superabsorbent polymer microsphere (SAP-MS) with monochromatic X-ray imaging.
abstract: This study was designed to evaluate the intravascular transformation behavior of superabsorbent polymer microsphere (SAP-MS) in vivo macroscopically by using monochromatic X-ray imaging and to quantitatively compare the expansion rate of SAP-MS among different kinds of mixtures. Fifteen rabbits were used for our study and transcatheter arterial embolization (TAE) was performed for their auricular arteries using monochromatic X-ray imaging. We used three kinds of SAP-MS (particle diameter 100-150 mum) mixture as embolic spherical particles: SAP-MS(H) absorbed with sodium meglumine ioxaglate (Hexabrix 320), SAP-MS(V) absorbed with isosmolar contrast medium (Visipaque 270), and SAP-MS(S) absorbed with 0.9% sodium saline. The initial volume of SAP-MS particles just after TAE and its final volume 10 minutes after TAE in the vessel were measured to calculate the expansion rate (ER) (n = 30). Intravascular behavior of SAP-MS particles was clearly observed in real time at monochromatic X-ray imaging. Averaged initial volumes of SAP-MS (H) (1.24 x 10(7) microm(3)) were significantly smaller (p < 0.001) than those of SAP-MS (V) (5.99 x 10(7) microm(3)) and SAP-MS (S) (5.85 x 10(7) microm(3)). Averaged final volumes of SAP-MS (H) were significantly larger than averaged initial volumes (4.41 x 10(7) microm(3) vs. 1.24 x 10(7) microm(3); p < 0.0001, ER = 3.55). There were no significant difference between averaged final volumes and averaged initial volumes of SAP-MS (V) and SAP-MS (S). SAP-MS (H), which first travels distally, reaches to small arteries, and then expands to adapt to the vessel lumen, is an effective particle as an embolic agent, causing effective embolization.
authors.affiliation: Department of Radiology, Kawasaki Medical School, 577 Matsushima, Kurashiki City, Okayama, 701-0192, Japan, daigoro@med.kawasaki-m.ac.jp.
authors.forename: Daigo
authors.initials: D
authors.lastname: Tanimoto
authors.forename: Katsuyoshi
authors.initials: K
authors.lastname: Ito
authors.forename: Akira
authors.initials: A
authors.lastname: Yamamoto
authors.forename: Teruki
authors.initials: T
authors.lastname: Sone
authors.forename: Makito
authors.initials: M
authors.lastname: Kobatake
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Tamada
authors.forename: Keiji
authors.initials: K
authors.lastname: Umetani
mesh_terms: D000704:Analysis of Variance; D000792:Angiography / Q000379:methods*; D000818:Animals; D001808:Blood Vessels / Q000187:drug effects* / Q000473:pathology; D002404:Catheterization / Q000379:methods; D003952:Diagnostic Imaging / Q000379:methods; D004195:Disease Models, Animal; D054644:Ear Auricle / Q000098:blood supply*; D004621:Embolization, Therapeutic / Q000379:methods*; D005260:Female; D007485:Ioxaglic Acid / Q000008:administration & dosage*; D008297:Male; D008863:Microspheres; D010316:Particle Size; D011108:Polymers / Q000494:pharmacology; D011817:Rabbits; D011897:Random Allocation; D012016:Reference Values
chemical_list: D011108:Polymers; D007485:Ioxaglic Acid