Complications of cannulation of the ascending aorta for open heart surgery.

In a series of 420 ascending aortic cannulations for cardiopulmonary bypass, major complications occurred in three patients. Aortic dissection occurred in one patient believed to be due to aortic cross-clamping. Avoidance of this manœuvre is suggested when the aorta is grossly atheromatous. Two patients developing false aneurysms due to mediastinal infection are described. Prevention of mediastinal infection and its treatment are discussed. The method of treatment of false aneurysms by deep hypothermia is described.