Induction of Cerebral Arterial Gas Embolism in Rat

The objective of our research group is to develop preclinical model of cerebral arterial gas embolism. This will facilitate the study of its pathophysiology and enable the optimization of therapeutic approaches, thereby enhancing knowledge and improving patients'care. Recent developments in our field have focused on hyperbaric oxygen therapy.

In addition, research is being conducted on the efficacy of different gas mixtures for the use of HBOT. We have identified challenges for replicating previous models due to a lack of detailed methodology for creating microbubbles. To address this issue, we have developed open-source software for measuring microbubbles.

We also provided a blueprint for an air bubble generator for improving reproducibility. Our group will focus on developing new therapies to treat cerebral arterial gas embolism using hyperbaric therapy with different gas mixtures and pressures. We will also investigate how blood pressure influences outcomes to further enhance patients'recovery.

To begin, prepare the surgical area with a sterile cloth placed under the rat. Lay out all surgical instruments and sutures on a second sterile cloth. Also prepare any necessary medication.

Set the heating pad with a feedback system to 37 degrees Celsius. Then adjust the microscope to the correct height for the procedure. Using both hands, remove the rat from its home cage.

After anesthetizing the rat, weigh it on an electronic balance. Next, apply artificial tears to the rat's eyes to prevent drying. Lubricate the temperature probe and insert it rectally.

After placing the rat in a supine position, place a 10-milliliter syringe under the neck for easy access to the surgical area. Using tape, secure the front paws of the rat to the surgery table. After making a midline incision, employ two tweezers to carefully dissect the connective tissue to expose the underlying muscles.

Then gently separate the left and right sternohyoid muscles by tearing the connective tissue in between. Identify and retract the right sternomastoid and right omohyoid muscles caudally and medially. The right-sided carotid triangle should now be visible.

To prepare the common carotid artery or CCA, remove the overlying fascia and adipose tissue. Gently move the vagus nerve apart from the CCA to separate them without causing damage. Ensure not to touch or press against the trachea while preparing the vessels.

Then use curved tweezers to place a 3-0 thread around the CCA. Secure the thread with hemostats to elevate the CCA in a later step. Locate and expose the bifurcation of the ECA and ICA.

Clear any surrounding fascia and adipose tissue as necessary, and temporarily ligate the ECA using a 3-0 suture. After locating the occipital artery branching from the medial side of the ECA, temporarily ligate the occipital artery proximally with a 3-0 suture. Follow the ICA distally until the pterygopalatine artery is located, which branches laterally.

Clear the surrounding fascia and adipose tissue while being cautious not to damage the vagus nerve. Then temporarily ligate the pterygopalatine artery using a 3-0 suture. Start the saline run through the air bubble generator's catheter, but do not generate air bubbles yet.

Using the hemostats placed earlier, gently elevate the CCA. Insert the needle attached to the catheter from the air bubble generator into the lumen of the CCA. After the needle is inserted, slowly lower the hemostats in CCA to allow blood reperfusion.

Check for any leakage of blood or saline at the insertion site. Then start the embolization process by running the Python code and initiating the creation of air bubbles. Once the embolization is complete, using the hemostats, elevate the CCA again and carefully retract the needle from the CCA.

Apply pressure to the insertion site with a cotton tip while maintaining the elevation of the CCA to stop any bleeding. Continue applying pressure to the puncture site. Then gently roll the cotton tip away distally along the CCA using minimal pressure to avoid disturbing the clot.

Afterward, carefully retrieve the 3-0 sutures from the ECA, OA, PPA, and CCA to allow reperfusion. Confirm that bleeding has permanently stopped and clean any residual blood around the surgical area. Using a curved needle and 4-0 suture, close the skin with sutures, then administer subcutaneous bupivacaine at a concentration of 2.5 milligrams per milliliter around the incision site to alleviate pain.

Carefully transfer the rat to a recovery cage set at 33 to 35 degrees Celsius for 30 to 120 minutes.