It has been done. The trick is that the heart's empty at the time. Here are heavily-pruned portions of an article about beating-heart valve surgery with warm blood perfusion during the procedure (vs. the cold blood perfusions usually used to produce hypothermic arrest)...
From http://www.ctsnet.org/doc/9020
Simultanous Antegrade/Retrograde Normothermic Blood Perfusion of the Heart in Valvular and Other Complex Surgery (Beating Heart Valvular Surgery): A New Concept in Myocardial Protection by Tomas A. Salerno, MD, Mohan Thanikachalam, MD, Kushagra Katariya, MD, and Anthony L. Panos, MD
New Concept in Myocardial protection (Beating Valve Surgery): The Rationale
"The theoretical and conceptual basis for this new method of myocardial protection lies in warm heart surgery [3]...The combination of hypothermia, introduced by Bigelow [5], and potassium cardioplegic arrest, introduced by Melrose [6], became the most common methods of myocardial protection during the 60?s and 70?s. Later, the addition of blood to cardioplegia was seen as a way of providing oxygen, nutrients and buffer [7]....].
"In light of findings that warm blood cardioplegia added a measure of protection when placed at the beginning and at the end of cross clamp duration...the notion...was that aggressive cooling of the heart was not warranted.
"...Since its induction, multiple studies have shown that warm heart surgery is comparable to cold cardioplegia in its safety record. From a metabolic standpoint, it provides superior myocardial protection. As well, high-risk patients who may have metabolically compromised hearts show greater benefit from reduced ischemic damage of the myocardium [11,12].
"..As a natural extension of warm heart surgery, beating heart valve surgery was born. Again fundamental questions were posed: why arrest the heart if technically adequate valve procedures could be accomplished with continuous warm perfusion?
"In order to avoid myocardial edema, which is intrinsic to an arrested heart [16] and to avoid ischemia-reperfusion injury [1] our group began performing beating heart valve surgeries about 6 years ago. With the aorta clamped, warm blood is given simultaneously antegrade and retrograde, continuously perfusing the heart. During the aortic clamping period, the electrocardiogram remained normal while the empty heart continued to beat. The technical detail of blood in the operative field was overcome in most of these procedures with small changes in the surgeon?s techniques. Air removal and prevention of air embolization were also overcome utilizing similar techniques as for regular procedures.
"Weaning from CPB was noted to be much easier when compared to the cardioplegic method. Furthermore, ventricular fibrillation seldom occurred and patients seemed to do better in general.
"Preliminary data from our group, and others, suggest that beating heart valve surgery is safe and that there may be a benefit to high risk patients [17-21]. We believe that combined antegrade and retrograde perfusion provides the best myocardial protection possible for the entire heart... Furthermore, we currently perform beating heart mitral valve surgery without aortic cross clamp thus eliminating the need for retrograde or antegrade perfusion..."
From http://www.ctsnet.org/doc/9020
Simultanous Antegrade/Retrograde Normothermic Blood Perfusion of the Heart in Valvular and Other Complex Surgery (Beating Heart Valvular Surgery): A New Concept in Myocardial Protection by Tomas A. Salerno, MD, Mohan Thanikachalam, MD, Kushagra Katariya, MD, and Anthony L. Panos, MD
New Concept in Myocardial protection (Beating Valve Surgery): The Rationale
"The theoretical and conceptual basis for this new method of myocardial protection lies in warm heart surgery [3]...The combination of hypothermia, introduced by Bigelow [5], and potassium cardioplegic arrest, introduced by Melrose [6], became the most common methods of myocardial protection during the 60?s and 70?s. Later, the addition of blood to cardioplegia was seen as a way of providing oxygen, nutrients and buffer [7]....].
"In light of findings that warm blood cardioplegia added a measure of protection when placed at the beginning and at the end of cross clamp duration...the notion...was that aggressive cooling of the heart was not warranted.
"...Since its induction, multiple studies have shown that warm heart surgery is comparable to cold cardioplegia in its safety record. From a metabolic standpoint, it provides superior myocardial protection. As well, high-risk patients who may have metabolically compromised hearts show greater benefit from reduced ischemic damage of the myocardium [11,12].
"..As a natural extension of warm heart surgery, beating heart valve surgery was born. Again fundamental questions were posed: why arrest the heart if technically adequate valve procedures could be accomplished with continuous warm perfusion?
"In order to avoid myocardial edema, which is intrinsic to an arrested heart [16] and to avoid ischemia-reperfusion injury [1] our group began performing beating heart valve surgeries about 6 years ago. With the aorta clamped, warm blood is given simultaneously antegrade and retrograde, continuously perfusing the heart. During the aortic clamping period, the electrocardiogram remained normal while the empty heart continued to beat. The technical detail of blood in the operative field was overcome in most of these procedures with small changes in the surgeon?s techniques. Air removal and prevention of air embolization were also overcome utilizing similar techniques as for regular procedures.
"Weaning from CPB was noted to be much easier when compared to the cardioplegic method. Furthermore, ventricular fibrillation seldom occurred and patients seemed to do better in general.
"Preliminary data from our group, and others, suggest that beating heart valve surgery is safe and that there may be a benefit to high risk patients [17-21]. We believe that combined antegrade and retrograde perfusion provides the best myocardial protection possible for the entire heart... Furthermore, we currently perform beating heart mitral valve surgery without aortic cross clamp thus eliminating the need for retrograde or antegrade perfusion..."
