Exogenous Amylase Reverses Cerebral Ischemia Induced by Selective Intraarterial Injection of Degradable Starch Microspheres: An Angiographic and Histological Study in a Novel in Vivo Animal Model.

To validate a new particulate embolization method using degradable starch microspheres (DSM) and intraarterial exogenous amylase administration, which allow for regulated temporary cerebral arterial embolization without compromising tissue perfusion. Twenty-four male New Zealand rabbits were randomly divided into three groups. All animals underwent routine angiography. The control group received no additional intervention. In the ischemia group, 0.2ml DSM was administered to the animals via the right carotid artery with pulsed, gentle injections to induce ischemia in the cerebral microcirculation. Animals in the reperfusion group received 0.05 ml of exogenous amylase along with DSM administration. Six hours after the procedure, the animals were sacrificed and histopathological analysis was performed. The ischemia group was the most adversely affected group by embolization, with the highest number of pyknotic neurons. The reperfusion group, which received exogenous amylase, had lower pyknotic neurons than the ischemia group. The pyknotic neuron count was similar in some regions between reperfusion and control groups. Exogenous amylase can rapidly attenuate cerebral ischemia caused by microembolization with DSM.