Alternative surgical exposure of the rat heart in vivo using a simple abdominal approach.

Access to the heart in laboratory rats is usually performed via a median sternotomy or a lateral thoracotomy. An alternative, less traumatic approach to the in vivo rat heart with improved survival is described. The technique uses an upper median laparotomy extending alongside the xyphoid bone. The xyphoid bone is retracted in a rostral direction, and a T-shaped cut is made in the diaphragm thus opening the thoracic cavity. Using a retractor the opening in the diaphragm is spread and the heart is exposed. We performed this abdominal approach in 23 anaesthetised and mechanically ventilated (for 2 h) rats and found physiologic intra-operative haemodynamics, a good postoperative recovery and 0% mortality.