Water-soluble polyvinyl alcohol microspheres for temporary embolization: Development and in vivo characteristics in a pig kidney model

Yuzo Shomura, Noboru Tanigawa, Mitsuo Shibutani, Shinya Wakimoto, Kazutoshi Tsuji, Takanori Tokuda, Jiro Terada, Shuji Kariya, Hiroyuki Kojima, Atsushi Komemushi, Satoshi Sawada

Research output: Contribution to journalArticlepeer-review

13 Citations (Scopus)


Purpose To preliminarily examine whether solubility of water-soluble polyvinyl alcohol (PVA) microspheres in blood plasma changes in proportion to their degrees of saponification. The study also examined their feasibility as a temporary embolic agents in the pig renal artery. Materials and Methods Three types of PVA microspheres with the degrees of saponification of 97 mol% (S97), 98 mol% (S98), and 99 mol% (S99) were prepared. Seven kidneys in seven miniature pigs were embolized and divided into three groups so there would be at least two kidneys for each type of PVA. One animal in each group was euthanized immediately after angiography at 3 hours after embolization and the other one at 7 days after. In addition, one animal embolized with S99 microspheres was euthanized at 21 days after embolization. Results With S97 microspheres, the vascular network had recovered to the preembolic state by 3 hours after embolization. With S98 microspheres, blood flow in the third-order branch had been restored in the same period. With S99 microspheres, the second- and lower order branches remained occluded until 21 days. Histopathologic specimens harvested at 3 hours revealed only a trace of PVA for S97 microspheres. With S98 microspheres, the vascular lumen was still found to be filled with PVA gel. With S99 microspheres, swollen microspheres densely filled the vascular lumen even on day 21. Conclusions Dissolution process in vitro and the duration of arterial occlusion in vivo were possibly related to the degree of saponification of PVA. This result may support feasibility of PVA microspheres as a temporary embolic agent.

Original languageEnglish
Pages (from-to)212-219
Number of pages8
JournalJournal of Vascular and Interventional Radiology
Issue number2
Publication statusPublished - Feb 2011
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Radiology Nuclear Medicine and imaging
  • Cardiology and Cardiovascular Medicine


Dive into the research topics of 'Water-soluble polyvinyl alcohol microspheres for temporary embolization: Development and in vivo characteristics in a pig kidney model'. Together they form a unique fingerprint.

Cite this