A Modified Technique for Transverse Aortic Constriction in Mice

This protocol provides a rapid surgical trauma limited, uncomplicated, and inexpensive masses to perform TAC surgery. This model approaches the aortic arch using a self-made retractor and does not need microsurgical scale or mechanical ventilation, thereby significant limiting surgical trauma. To begin, prepare a five milliliter syringe.

Then make the needle blunt by pinching off its tip with a needle holder. Prepare a 27 gauge needle blunted with a needle holder and bend its tip at 90 degrees. Use a commercially obtained iron wire and twine it around the needle.

Form a small snare or loop at the blunted tip of the needle. Sterilize all the surgical tools before surgery by autoclaving. Confirm the depth of anesthesia with a toe pinch to prevent dryness while under anesthesia.

Apply ophthalmic ointment to both eyes. Then place the mouse in the supine position on a heating pad covered with a sterile drape with its head pointing to the operator. Fix its extremities with adhesive tape and incisors with a 4-0 suture.

Now, insert a rectal probe to monitor body temperature during the operation. Using sterilized ophthalmic scissors, cut a hole in a new, disposable sterile drape. Place the sterile drape over the mouse and ensure the un-haired operating field is visible through the hole.

After making an incision separate the skin and the superficial fascia and expose the trachea and proximal sternal. Then carefully make a three to four millimeter longitudinal midline incision to the sternum from the upper edge to the sternal angle and gently lift the sternum with forceps. Using straight forceps bluntly dissect the target vessel and tissues around it.

Now, hold the previously self-made retractor with a wire snare in the right hand. Carefully pass the snare of the retractor under the aorta between the left common carotid artery and the origin of the right denominate artery. Pass the retractor to the left hand.

Hold the microscopic tweezers in the right hand and pass a 7-0 silk suture through the snare loop at the end. Pull out the retractor. Place a 27 gauge needle parallel to the aorta and tie the suture around the needle and the aorta.

Then hold the 27 gauge needle with ophthalmic forceps and the knot tied to the 27 gauge needle and aorta with another forceps. Quickly but gently pull the 27 gauge needle from the ligation. Suture the skin with 4-0 synthetic monofilament suture in an interrupted suture pattern.

Place the mouse on a warm pad and wait for it to revive. Generally, the mouse revives in about 60 minutes. After four weeks of surgery.

Ejection fraction and fractional shortening were significantly reduced in transverse aortic constriction mice compared to sham mice. However, left ventricular mass and left ventricular internal diameter were significantly elevated in the transverse aortic constriction mice. The most important step in this particle is passing suture under the aortic arch.

All movies must be gentle to reduce unnecessary traction to the artery. Following this procedure researchers can apply medical treatment to the animal model in order to investigate potential therapeutic targets to patients with cardio hypertrophy or heart failure.