Geometry of the proximal pulmonary trunk during dilation with two balloons

Balloon dilation is an accepted method of treating congenital valvar pulmonary stenosis.^1-5 In older patients, the diameter of the pulmonary anulus may be so great that a balloon diameter larger than those commercially available is needed. Some have circumvented this problem by simultaneously inflating 2 balloons across the pulmonary valve.² To predict the diameter and area that result from simultaneous inflation of 2 balloons across the pulmonary valve, it is important to know if distortion of balloon shape occurs, and the resulting geometry of the proximal pulmonary trunk. This study examines these questions by observing the result of inflation of 2 balloons across the pulmonary valve in excised normal canine hearts.