After anesthetizing the rat and disinfecting the surgical area, make a two centimeter incision along the midline of the neck using a surgical blade. Employ retractors to laterally pull back the skin and salivary glands exposing the sternocleidomastoid, and cervical muscles. Then separate the sternocleidomastoid and cervical muscles to expose the carotid territory.
Separate the common carotid artery and identify the vascular anatomy of the common internal and external carotid artery. Then separate the common carotid artery derived external carotid artery and internal carotid artery. Using a three oh silk thread tie an easily untangled knot over the external carotid artery and common carotid artery to temporarily block blood flow.
Position a vessel clip on the common carotid artery approximately 0.5 centimeters from the first knot, and place a loose knot between the first vascular clip and the silk thread knot. Now dye the needle of a five milliliter syringe black. Then using the black dyed needle, create a small puncture in the common carotid artery and mark the pinholes in black.
Insert the monofilament nylon suture into the common carotid artery through the black mark. Open the vascular clip and guide the nylon wire into the internal carotid artery until it halts with slight resistance. Then tighten the second knot securely to keep the monofilament nylon suture in place inside the artery preventing displacement from the blocking position.
Untie the knots on the external carotid artery to allow blood reperfusion. After securing the monofilament suture and withdrawing it, release the knot on the common carotid artery. Apply a vascular clip ahead of the fixed monofilament suture to prevent bleeding.
Then replace the first common carotid artery knot with a vascular clip. Use tweezers to rotate the vessel incision sideways. Clamp the incision with tweezers and ligate it using a six oh thread to repair the incision.
Remove the vascular clip, check for leaks, and confirm complete reperfusion. Laser speckle flow imaging revealed that before occluding the middle cerebral artery or MCA, there was abundant blood flow in the MCA area. Upon occlusion of the MCA, the blood flow value on the ischemic side of the brain rapidly decreased.
Blood flow on the ischemic side was rechecked before removing the suture, confirming MCA occlusion with only a slight change in blood flow. Upon withdrawing the suture, blood flow perfusion swiftly recovered.
