The "90 degrees bent" two-stage venous cannula.

A 90 degree bent two-stage venous cannula for cardiopulmonary bypass is presented and discussed. Its main advantages, compared to similar straight ones, are that it is out of the way of the surgeon, by being placed under the right sternum and also that the venous return seems uninfluenced by displacement of the heart when operating on the posterior side of the heart. No major drawbacks for the cannula have been noticed so far.