Apical Resection Neonatal Mouse Model: A Surgical Procedure to Amputate the Ventricular Apex to Study Regenerative Potential in a Neonate Mouse Heart

Begin by pre-cooling the bronze operating platform overnight at minus 20 degrees Celsius. Take the anesthetized mouse out of the icebox and put it on the platform. Anchor the mouse in a supine position using medical adhesive tape. Put the operating platform with the mouse under a stereoscope, and disinfect the mouse chest using a prep pad soaked with betadine and 70% alcohol.

Incise the skin with a 1-centimeter cut at the fourth intercostal area of the chest cavity, and separate the intercostal muscles using microsurgical scissors until the heart is accessed. Alternately press the chest and abdomen with the help of two forceps until the heart is exteriorized out of the chest, without any mechanical damage.

Set the ribs below and above the small incision as a natural fixation to immobilize the heart. Locate the apex of the left ventricle and cut a 1-millimeter diameter of ventricular apex tissue using iridectomy scissors. Confirm that the left ventricular chamber is exposed and begins oozing.

Gently press the heart back into the chest cavity using a cotton swab. Suture the muscles, ribs, and skin using 8-0 proline sutures, and clean the mouse thoroughly after the operation. Transfer the mouse from the operating platform to a 37-degree heating blanket to warm up the body immediately after the operation.

Confirm anabiosis of the mouse by observing for the signs of spontaneous respiration restoration, skin color change from pale to pink, and movement of limbs. Take the operated mouse back to its mother, once it has recovered. Mingle the operated mouse and its mother's nesting materials if necessary.