Hydrogen peroxide-induced stroke: elucidation of the mechanism in vivo

Object. Hydrogen peroxide (H(2)O(2)) is used as a hemostatic agent in many neurosurgery centers. The authors used a 3% H(2)O(2) solution for final hemostasis after removal of a left insular tumor. Immediately afterward, air bubbles were observed within the lumen of the polar temporal artery. Postoperative MR imaging revealed punctate areas of infarction in the lenticulostriate artery territory. The authors designed an experimental Study to elucidate the mechanism of remote O(2) emboli and reactive O(2) species-related vasoactive responses and thrombus formation. Methods. In this study, H(2)O(2) irrigation was used in mice with either an intact pial layer or after the pia mater was removed through a corticotomy. Normal saline irrigation was used in the corresponding control groups. Vessels were examined for intravascular O(2) emboli under the microscope. Tissue sections were then obtained and stained with H & E and the 3-nitrotyrosine (3-NT) antibody to evaluate intravascular thrombus formation and peroxynitrite reaction, respectively. Results. Multiple bubbles were observed within the lumen of the vessels after exposure to H(2)O(2) regardless of whether the pial layer was destroyed or intact. Immunofluorescent staining for 3-NT showed an abundant positive reaction in the vessel walls of all animals exposed to H(2)O(2) as well as vascular occlusion with acute thrombus formation. Samples taken from the animals that received saline showed no positive staining for 3-NT and no vascular occlusion. Conclusions. Exposure to H(2)O(2) may cause serious ischemic complications. The formation of peroxynitrite may cause vasoactive responses to H(2)O(2) and platelet aggregation/thrombus formation, and the free diffusion of H(2)O(2) through the vessel walls and its conversion to water and O(2) leads to O(2) bubbles within the closed vessel lumen. If used intradurally, H(2)O(2) may have deleterious ischemic effects, and it can only be used carefully in open extradural spaces. (DOI: 10.3171/2008.3.17434)