Surgery-related thrombosis critically affects the brain infarct volume in mice following transient middle cerebral artery occlusion

PLoS One. 2013 Sep 24;8(9):e75561. doi: 10.1371/journal.pone.0075561. eCollection 2013.

Abstract

Transient middle cerebral artery occlusion (tMCAO) model is widely used to mimic human focal ischemic stroke in order to study ischemia/reperfusion brain injury in rodents. In tMCAO model, intraluminal suture technique is widely used to achieve ischemia and reperfusion. However, variation of infarct volume in this model often requires large sample size, which hinders the progress of preclinical research. Our previous study demonstrated that infarct volume was related to the success of reperfusion although the reason remained unclear. The aim of present study is to explore the relationship between focal thrombus formation and model reproducibility with respect to infarct volume. We hypothesize that suture-induced thrombosis causes infarct volume variability due to insufficient reperfusion after suture withdrawal. Seventy-two adult male CD-1 mice underwent 90 minutes of tMCAO with or without intraperitoneal administration of heparin. Dynamic synchrotron radiation microangiography (SRA) and laser speckle contrast imaging (LSCI) were performed before and after tMCAO to observe the cerebral vascular morphology and to measure the cerebral blood flow in vivo. Infarct volume and neurological score were examined to evaluate severity of ischemic brain injury. We found that the rate of successful reperfusion was much higher in heparin-treated mice compared to that in heparin-free mice according to the result of SRA and LSCI at 1 and 3 hours after suture withdrawal (p<0.05). Pathological features and SRA revealed that thrombus formed in the internal carotid artery, middle cerebral artery or anterior cerebral artery, which blocked reperfusion following tMCAO. LSCI showed that cortical collateral circulation could be disturbed by thrombi. Our results demonstrated that suture-induced thrombosis was a critical element, which affects the success of reperfusion. Appropriate heparin management provides a useful approach for improving reproducibility of reperfusion model in mice.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anterior Cerebral Artery / pathology
  • Brain / drug effects
  • Brain / pathology*
  • Brain Ischemia / pathology
  • Carotid Artery, Internal / drug effects
  • Carotid Artery, Internal / pathology
  • Cerebrovascular Circulation / drug effects
  • Cerebrovascular Circulation / physiology
  • Disease Models, Animal
  • Heparin / administration & dosage
  • Infarction, Middle Cerebral Artery / pathology*
  • Injections, Intraperitoneal
  • Ischemic Attack, Transient / pathology
  • Male
  • Mice
  • Middle Cerebral Artery / drug effects
  • Middle Cerebral Artery / pathology*
  • Reperfusion / adverse effects*
  • Reperfusion Injury / pathology
  • Thrombosis / pathology*

Substances

  • Heparin

Grant support

This study was supported by the National Basic Research Program (973 Program 2010CB834306 (GYY, YTW), the National Natural Science Foundation of China (Project #U1232205) and KC Wong Foundation (GYY). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.