Occluding the junction of the middle cardiac vein in retrograde cardioplegia: a new retrograde cannula for optimizing retrograde cardioplegic delivery.

Retrograde cardioplegia often fails to provide adequate perfusion of the right ventricle and the posterior wall of the left ventricle because of the shunt through the thebesian vein. However, much of the retrograde cardioplegic solution may leak into the right atrium after veno-venous anastomoses at the apex of the heart, especially when a retrograde balloon cannula is inserted too deeply in the great cardiac vein, although this is not widely recognized. We designed a new retrograde cardioplegic cannula with three self-inflating balloons, which reduced the shunt flow by occluding the junction of the middle cardiac vein and improving in cardioplegic delivery. We describe the myocardial dye distribution achieved by using this new cannula in pig hearts and report the results of its clinical application.