After left anterior descending coronary artery preparation and extubating the anesthetized mouse, insert the vertical side part and the slits on the base plate of the purpose-built ischemia-reperfusion injury tool. Using a fine hook, retrieve the two suture ends and pull them through the central hole on the side part behind the balloon. Guide one end of the suture above and around the balloon, and subsequently navigate the opposite end under and around the balloon.
Direct the ends of the suture through the slits on top of the side part. On the distal part of the suture, attach a 2.1 gram weight to keep each suture end in place. To induce ischemia, quickly inflate the balloon using the vascular balloon pump up to two bars.
After locking the pump, confirm the balloon inflation and check that the weights are lifted. Confirm the ischemia by observing the change in the ECG trace. After 30 minutes, unlock the pump to stop the occlusion.
Confirm that the balloon is deflated and weights are lowered. Cut the suture and tubing between the mouse and the side part, then carefully remove the side part. Apply gel at the insertion side of the tubing into the thorax.
Using curved forceps, gently push the skin against the tube, and with another forceps, extract the tube. Cut any remaining suture close to the skin. Place an additional 5-0 polypropylene suture to seal the exit side of the tube and minimize the risk of air entry into the thorax.
In this study, myocardial viability after ischemia-reperfusion injury was investigated. Triphenyl tetrazolium chloride staining differentiated viable from non-viable myocardial regions in mice. No significant differences were observed between the standard and remote ischemia-reperfusion injury techniques.
Late gadolinium enhancement magnetic resonance imaging revealed no notable differences in the area at risk between standard and remote ischemia-reperfusion injury techniques. The sirius red staining differentiated the necrotic core from viable tissue. The calculated scar sizes revealed no notable differences in the area at risk between the two ischemia-reperfusion injury methods.
Using a custom-built remote occlusion tool within the MRI scanner, contrast differences between non-infarcted and infarcted regions were observed. ECG traces before and after occlusion confirmed successful occlusion of the left anterior descending coronary artery.
