the mitral valve is located far from midline sternotomy , but is very close to the interatrial groove . as our experience grew and we learned from embryology , we found that a more cental left atriotomy was advantageous , and possible by interatrial groove dissection using ultrasonic scalpel . under general anesthesia , midline sternotomy is performed and the ascending aorta is cannulated for arterial inflow , and the superior vena cava and right atrial appendage are cannulated for venous outflow . the fad pad covering the interatrial groove is dissected under cardiopulmonary bypass by ultrasonic scalpel . the dissection is carried out in the exact groove of sondergaard until accessing beneath the thin atrial septum with careful attention paid to the coronary sinus vein ( fig . the aorta is cross - clamped and a vertical incision is made onto the left atrium , leaving enough room for the atrial wall to close . using a self - retaining retractor , atrial tissue above the anterior mitral annulus this makes a tractile and stretched wide view of the mitral valve possible because the left atrium wall hook - up is optimal . this is quite different from the right side left atriotomy , which usually leaves a redundant left atrial wall to be hooked up . because the mitral valve is such a complex anatomic structure and the maneuvers involved in correcting a regurgitant valve may vary from the simple to the very complex , adequate exposure is an absolute requirement in every operative plan . the first critical step to standard valve repair is the complete and thorough development of the sondergaard plane reflecting the right atrium off the left atrium to the atrial septum . this was first described in the 1950s by the danish surgeon sondergaard to expose the atrial septum for noncardiopulmonary bypass treatment of atrial septal defects . regardless of claims from previous procedures , it should always be possible to dissect out the groove without significant difficulty . the complete and full development of the groove is crucial for obtaining adequate exposure of the mitral valve . with this technique , via blunt and sharp dissection with ultrasonic scalpel , we had no need for any other incision for mitral valve repair or replacement , whether for primary surgery or reoperation . this incision brings the surgeon very close to the mitral valve even in the most difficult anatomic situations . once the right atrium is dissected off the left atrium , a generous incision in the left atrium is made , avoiding the atrial septum . we have been adopting this incision and approach in 10 consecutive patients and have found that the aortic cross - clamp time decreased significantly from an average 75 minutes to 48 minutes compared to right - side left atriotomy patients . a more central incision onto the left atrium
abstractexposure of the mitral valve is of critical importance in mitral valve surgery . 
 the mitral valve is located near the interatrial groove . 
 as we accumulated experience and learned from embryology , we found that a more central left atriotomy was advantageous , and was made possible by interatrial groove dissection using an ultrasonic scalpel . 
 this crucial finding prompted us to report the technique .