This article describes a surgical procedure to induce subarachnoid hemorrhage in a mouse model. The method involves ligating and occluding arteries to create a controlled hemorrhage for research purposes.
Take an anesthetized mouse with a shaved neck.
Disinfect the neck and make a midline incision.
Expose the common carotid artery, or CCA, which bifurcates into the external carotid artery, or ECA, and internal carotid artery, or ICA.
Ligate the ECA and temporarily occlude both the CCA and ICA to restrict blood flow.
Incise the ECA, insert a filament, and advance it into the CCA.
Reopen the CCA and ICA to restore blood flow. Redirect the filament through the ICA toward the brain to perforate the anterior cerebral artery, a branch of the ICA.
The perforation causes bleeding, or hemorrhage, into the subarachnoid space, a fluid-filled area surrounding the brain. Confirm the hemorrhage by observing clinical symptoms.
Close the CCA to stop blood flow, remove the filament, and ligate the ECA incision.
Reopen the CCA to continue subarachnoid bleeding.
Suture the skin and allow the mouse to recover for analysis.
Begin by shaving the neck hair of the mouse. Apply ophthalmic ointment during the procedure. Sanitize the skin with 70% ethanol, followed by betadine or chlorhexidine, and apply 1% lidocaine. Place the mouse in a supine position with its head and torso facing an upward direction.
Stabilize the mouse dorsally by using tape on the four extremities. Stretch the skin of the neck and elevate it. Unfold the neck skin from the chin to the upper edge of the breastbone and separate salivary glands from the adjacent connective tissue. Expose the common carotid artery sheath by separating the muscles along one side of the trachea.
Expose the surgical field with a retractor or sterile gauze swab, and detach the carotid artery, and leave a free 8-0 silk suture without ligating it, ensuring not to damage the vagal nerve. Dissect the distal end of the ECA, and ligate the vessels twice in a distal position.
At the midpoint of the twice-ligated filament segment, disjoin the ECA and create a vessel stump. Leave a silk suture around the ICA without closing it. Prearranged one ligation for the filament around the ECA stump. Do not close it until successful filament insertion.
Close the ICA and CCA temporarily by using a suture or a micro clip. Using microvascular scissors, make an incision in the ECA and insert a 5-0, alternatively 4-0 prolene filament, and advance it into CCA. Close the ligature on the ECA while detaching the micro clip on the ICA and CCA.
Pull back the filament gently and adjust the ECA stump in the cranial direction while invaginating the filament through the bifurcation into the ICA. Place the filament tip medially at an angle of approximately 30 degrees to the tracheal midline and horizontal plane and push it inside ICA.
At the ACA-MCA bifurcation, resistance is observed. Move the filament forward up to 3 millimeters and perforate the right ACA. Quickly withdraw the filament to the ECA stump, allowing blood flow in the subarachnoid space. Place the filament in this position for 10 seconds. Withdraw the filament. The CCA can be temporarily closed beforehand to avoid excessive blood loss. And then, withdraw the filament.
Ligate the ECA using prearranged sutures, and reopen the CCA if you have closed it before. The presence of muscle tremors, ipsilateral miosis, gasping for breath, altered heart rhythm, and urinary incontinence can be supporting evidence of successful surgery. Ensure that there is no bleeding leakage and disinfect the skin. Suture the wound, place the mouse in a thermal box, and wait until the animal has sufficient consciousness to have sternal recumbency.
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