CORRESPONDENCE
Nonhemic Prime in CardiopulmonaryBypass To the Editor: The valuable editorial on erythropoietin that was published in The Annals recently [l] appeared to imply that the introduction of a nonhemic prime for cardiopulmonary bypass, producing intentional hemodilution-a major advance in the development of open heart surgery-was the contribution of Dr Cooley and his associates in Houston. I wish to correct this misunderstanding. Although the Houston group became late advocates of this technique, the credit for this work-which enabled open heart surgery to expand rapidly and safely on a scale not previously envisaged-must go solely to Nazih Zuhdi of Oklahoma City. Until February 1959, pump oxygenators had been uniformly primed with large volumes of fresh heparinized blood obtained from donors on the day of operation. In that month, Dr Zuhdi and his colleagues were the first to introduce a citrated banked blood prime [2], which greatly facilitated preparation for open heart surgery. By coupling this innovation with the design and development of a low-volume reservoir heart-lung machine (which had the additional advantage of incorporating a volumereducing heat exchanger allowing internal hypothermic perfusion), the quantity of (banked) blood required for the procedure was greatly reduced. The final step (or "quantum leap") was taken by Dr Zuhdi on February 25, 1960, when, after his extensive laboratory studies in 1959, he introduced into his clinical cardiac surgery program the use of a totally nonhemic pump oxygenator prime using 5% dextrose in water, inducing intentional hemodilution [24]. This advance, coupled with the small-capacity pump oxygenator, probably did more than any other single innovation to enable open heart operations to be performed in the numbers to which we have become accustomed today. Before nonhemic priming was introduced, it was estimated that not more than 50 to 75 open heart procedures were performaed in the United States each day. Foote, Long, Gadboys, Dewall, and their respective colleagues soon followed this lead, but it was not until the April 1961 issue of the Journal of the American Medical Association that the Houston group-after direct communication with Dr John Carey of the Oklahoma City group-discussed the potential benefits of a nonhemic prime, and not until November of that year that they described some pilot experimental studies [5]. Their first report of the clinical use of nonhemic prime appeared in November 1962 [6]-some 2 years after Zuhdi's initial report and almost 3 years after his initial clinical case. By that time, the employment of nonhemic primes, intentional hemodilution, and banked citrated blood for blood loss replacement was already an everyday occurrence in many active centers across the nation. Dr Zuhdi's leading role in this field was described by Dr Clarence Dennis in his laureate address to the American Society of Artificial Internal Organs in 1985 and was recognized by the American College of Cardiology in the Milestones of Cardiology in 1989. His contributions are possibly even more remarkable as both the experimental laboratory and clinical studies were carried out while he was in private cardiothoracic surgical practice in a community hospital in Oklahoma City. Truly important advances in any field of medicine are uncommon. The introduction of a nonhemic prime and intentional hemodilution for open heart surgery is one such advance. It is important that the individual (or individuals) responsible for the advance should receive due credit and recognition. In this case, those of us who followed have been reaping the rewards of Dr 8 1992 by The Society of Thoracic Surgeons
Zuhdi's endeavors for the past 30 years on a scale unimagined in the pre-Zuhdi era. D . K. C . Cooper, MD, PhD Oklahoma Transplantation lnstitute Baptist Medical Center 3300 Nw Expressway Oklahoma City, OK 73112
References 1. Goodnough LT, Geha A. A new era in blood conservation. Ann Thorac Surg 1991;51:703-4. 2. Zuhdi N, McCullough B, Carey M, Greer A. The use of citrated banked blood for open-heart surgery. Anesthesiology 1960;21:496-501. 3. Zuhdi N, McCullough B, Carey J, Greer A. Double-helical reservoir heart-lung machine. Designed for hypothermic perfusion; primed with 5%glucose in water; inducing hemodilution. Arch Surg 1961;82:3205. 4. Zuhdi N, McCullough B, Carey J, Kreiger C, Greer A. Hypothermic perfusion for open-heart surgical procedures. Report on the use of a heart-lung machine primed with five per cent dextrose in water inducing hemodilution. J Int Coll Surg 1961;35:319-26. 5. Cooley DA, Beall AC. A technic of pulmonary embolectomy using temporary cardio-pulmonary bypass. Cardiovasc Surg 1961;246%76. 6. Cooley DA, Beall AC, Grondin P. Open-heart operations with disposable oxygenators, 5 per cent dextrose prime, and normothermia. Surgery 1962;52713-9.
Reply
To the Editor:
We certainly appreciate Dr Cooper's letter drawing attention to the historical contributions of Dr Zuhdi of Oklahoma City to the concept and application of nonhemic primes for cardiopulmonary bypass. In our editorial, our reference to the 1962 report by Cooley and associates was meant to cite a reference to this methodology and its application in the conduct of cardiopulmonary bypass. We certainly did not intend to imply that Dr Cooley and his associates introduced the concept or originated its application. We thank Dr Cooper for bringing forward to the readership's attention the important contribution of Dr Zuhdi and his associates to the field of hemodilution for cardiopulmonary bypass, and for his historical and chronological review of their original introduction of this concept. Alexander S. Geha, M D Lawrence Tim Goodnough, M D Case Western Reserve University School of Medicine and University Hospitals of Cleveland 2074 Abington Rd Cleveland, OH 44106
Combined Superior-TransseptalApproach to the Mitral Valve To the Editor: Dr Berreklouw and his colleagues [l] have given an excellent report with illustrations of the combined superior-transseptal approach to the mitral valve. We have used this approach in 8 patients, of whom 4 had reoperations. Mitral valve replacement and repair were done in 6 and 2 patients, respectively. The mitral valve procedure was combined with tricuspid valve repair in 2 patients, coronary artery bypass grafting in 2 patients (along with use of retrograde Ann Thorac Surg 1992;53180-2
OOO3-4975/92/$3.50
Nonhemic Prime in CardiopulmonaryBypass To the Editor: The valuable editorial on erythropoietin that was published in The Annals recently [l] appeared to imply that the introduction of a nonhemic prime for cardiopulmonary bypass, producing intentional hemodilution-a major advance in the development of open heart surgery-was the contribution of Dr Cooley and his associates in Houston. I wish to correct this misunderstanding. Although the Houston group became late advocates of this technique, the credit for this work-which enabled open heart surgery to expand rapidly and safely on a scale not previously envisaged-must go solely to Nazih Zuhdi of Oklahoma City. Until February 1959, pump oxygenators had been uniformly primed with large volumes of fresh heparinized blood obtained from donors on the day of operation. In that month, Dr Zuhdi and his colleagues were the first to introduce a citrated banked blood prime [2], which greatly facilitated preparation for open heart surgery. By coupling this innovation with the design and development of a low-volume reservoir heart-lung machine (which had the additional advantage of incorporating a volumereducing heat exchanger allowing internal hypothermic perfusion), the quantity of (banked) blood required for the procedure was greatly reduced. The final step (or "quantum leap") was taken by Dr Zuhdi on February 25, 1960, when, after his extensive laboratory studies in 1959, he introduced into his clinical cardiac surgery program the use of a totally nonhemic pump oxygenator prime using 5% dextrose in water, inducing intentional hemodilution [24]. This advance, coupled with the small-capacity pump oxygenator, probably did more than any other single innovation to enable open heart operations to be performed in the numbers to which we have become accustomed today. Before nonhemic priming was introduced, it was estimated that not more than 50 to 75 open heart procedures were performaed in the United States each day. Foote, Long, Gadboys, Dewall, and their respective colleagues soon followed this lead, but it was not until the April 1961 issue of the Journal of the American Medical Association that the Houston group-after direct communication with Dr John Carey of the Oklahoma City group-discussed the potential benefits of a nonhemic prime, and not until November of that year that they described some pilot experimental studies [5]. Their first report of the clinical use of nonhemic prime appeared in November 1962 [6]-some 2 years after Zuhdi's initial report and almost 3 years after his initial clinical case. By that time, the employment of nonhemic primes, intentional hemodilution, and banked citrated blood for blood loss replacement was already an everyday occurrence in many active centers across the nation. Dr Zuhdi's leading role in this field was described by Dr Clarence Dennis in his laureate address to the American Society of Artificial Internal Organs in 1985 and was recognized by the American College of Cardiology in the Milestones of Cardiology in 1989. His contributions are possibly even more remarkable as both the experimental laboratory and clinical studies were carried out while he was in private cardiothoracic surgical practice in a community hospital in Oklahoma City. Truly important advances in any field of medicine are uncommon. The introduction of a nonhemic prime and intentional hemodilution for open heart surgery is one such advance. It is important that the individual (or individuals) responsible for the advance should receive due credit and recognition. In this case, those of us who followed have been reaping the rewards of Dr 8 1992 by The Society of Thoracic Surgeons
Zuhdi's endeavors for the past 30 years on a scale unimagined in the pre-Zuhdi era. D . K. C . Cooper, MD, PhD Oklahoma Transplantation lnstitute Baptist Medical Center 3300 Nw Expressway Oklahoma City, OK 73112
References 1. Goodnough LT, Geha A. A new era in blood conservation. Ann Thorac Surg 1991;51:703-4. 2. Zuhdi N, McCullough B, Carey M, Greer A. The use of citrated banked blood for open-heart surgery. Anesthesiology 1960;21:496-501. 3. Zuhdi N, McCullough B, Carey J, Greer A. Double-helical reservoir heart-lung machine. Designed for hypothermic perfusion; primed with 5%glucose in water; inducing hemodilution. Arch Surg 1961;82:3205. 4. Zuhdi N, McCullough B, Carey J, Kreiger C, Greer A. Hypothermic perfusion for open-heart surgical procedures. Report on the use of a heart-lung machine primed with five per cent dextrose in water inducing hemodilution. J Int Coll Surg 1961;35:319-26. 5. Cooley DA, Beall AC. A technic of pulmonary embolectomy using temporary cardio-pulmonary bypass. Cardiovasc Surg 1961;246%76. 6. Cooley DA, Beall AC, Grondin P. Open-heart operations with disposable oxygenators, 5 per cent dextrose prime, and normothermia. Surgery 1962;52713-9.
Reply
To the Editor:
We certainly appreciate Dr Cooper's letter drawing attention to the historical contributions of Dr Zuhdi of Oklahoma City to the concept and application of nonhemic primes for cardiopulmonary bypass. In our editorial, our reference to the 1962 report by Cooley and associates was meant to cite a reference to this methodology and its application in the conduct of cardiopulmonary bypass. We certainly did not intend to imply that Dr Cooley and his associates introduced the concept or originated its application. We thank Dr Cooper for bringing forward to the readership's attention the important contribution of Dr Zuhdi and his associates to the field of hemodilution for cardiopulmonary bypass, and for his historical and chronological review of their original introduction of this concept. Alexander S. Geha, M D Lawrence Tim Goodnough, M D Case Western Reserve University School of Medicine and University Hospitals of Cleveland 2074 Abington Rd Cleveland, OH 44106
Combined Superior-TransseptalApproach to the Mitral Valve To the Editor: Dr Berreklouw and his colleagues [l] have given an excellent report with illustrations of the combined superior-transseptal approach to the mitral valve. We have used this approach in 8 patients, of whom 4 had reoperations. Mitral valve replacement and repair were done in 6 and 2 patients, respectively. The mitral valve procedure was combined with tricuspid valve repair in 2 patients, coronary artery bypass grafting in 2 patients (along with use of retrograde Ann Thorac Surg 1992;53180-2
OOO3-4975/92/$3.50
