Muscle Grafting as a Surgical Strategy for Restoring Blood Flow to the Mouse Brain After Stroke

Abstract

Source: Paro, M. R., et.al. A Model for Encephalomyosynangiosis Treatment after Middle Cerebral Artery Occlusion-Induced Stroke in Mice. J. Vis. Exp. (2022).

This video demonstrates a surgical procedure to graft a vascularized muscle onto the brain surface following transient middle cerebral artery occlusion. The graft promotes new blood vessel formation in the ischemic region, enhancing oxygen and nutrient supply. Over time, the integrated muscle supports neuronal survival and aids in post-stroke recovery.

Protocol

All procedures involving animal models have been reviewed by the local institutional animal care committee and the JoVE veterinary review board.

1. Encephalomyosynangiosis (EMS) surgery
   1. After 60 min of middle cerebral artery occlusion (MCAo), randomize mice into MCAo-only or MCAo + EMS groups. Perform EMS 4 h after MCAo (MCAo + EMS group) or sham surgery for select experiments (EMS-only group). Change into a new pair of sterile surgical gloves before the surgery.
      NOTE: The mice recovered from anesthesia after 60 minutes of MCAo and were re-anesthetized before the EMS surgery.
   2. For groups that receive EMS (MCAo + EMS or EMS-only groups), make a 10-15 mm skin incision with scissors, extending from 1-2 mm rostral to the right ear to 1-2 mm caudal to the right eye.
      NOTE: Sterile scissors were used to prevent accidental damage to the temporalis muscles underneath.
   3. Retract skin flaps using clamps and visually identify the temporalis muscle and the skull.
   4. Bluntly dissect the temporalis muscle away from the skull using scissors with a spreading technique. Perform a 2-3 mm myotomy directed ventrally along the caudal border of the muscle to facilitate ventral reflection.
   5. Perform a craniotomy ~5 mm in diameter at the skull underneath the reflected temporalis muscle using a micro drill.
   6. Remove the dura mater with tweezers to expose the pial surface of the brain. Use extreme caution to avoid accidental injury to the brain.
   7. Suture the dorsal border of the temporalis muscle to the subcutaneous tissue of the dorsal skin flap with 6-0 monocryl filaments, making it flush to the exposed cerebral cortex.
   8. Close the skin incision with 6-0 monofilament suture. Place the mouse back into its cage and monitor until recovery from anesthesia. Return the mouse to its housing facility.

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
6-0 monocryl suture	Ethilon	697G
70% ethanol to sanitize operating surface	Walgreen
Bupivacaine 0.25% solution	Midwest Vet
Clamps for tissue retraction	Roboz
Doccal suture with Nylon coating	Doccal corporation Sharon MA	602145PK10Re
Electric heating pad for operating surface
Isoflurane anesthesia	Piramal Critical Care Inc
Isoflurane delivery apparatus	--B6Surgivet (Isotech 4)
Micro drill	Harvard Apparatus
Microdissecting tweezers, curved x2	Piramal Critical Care Inc
Mouse angiogenesis panel arrat	R& D biotech	ARY015
Needle driver	Ethilon
Operating microscope	Olympus
Operating surface	Olympus
Surgical scissors	Roboz