1020
CORRESPONDENCE
Ann Thorac Surg
1992:54:1018-24
assist device seems to be well-suited for long-term ventricular support. With the next generation of this device, a nontethered vented electric pump, such patients will be able to be fully mobile and return to a nearly normal lifestyle.
to the amelioration of cardiopulmonary bypass-induced coagulopathy brought about by the use of prebypass plateletpheresis.
Nelson A. Burton, M D W . Stephen Phillips, M D Quentin Macmanus, M D Edward A . Lefrak, M D
Gerald G. Davies, FFARCSI Douglas G. Wells, FFARACS Richard Sadler, M D Thomas M . Mabee, M D Mitchell Ruffcorn, M D John B. Dooley, M D
3301 Woodburn Rd Suite 301 Annandale, VA 22003
St. Luke’s Regional Heart Center 1228 E Rusholme Davenport, IA 52803
References
Plateletpheresis and Transfusion Practice in Heart Operations To the Editor: In a recent publication (11 we reported that prebypass plateletpheresis reduced the perioperative use of homologous blood products. One criticism of this study was the small number of patients involved. We commenced plateletpheresis in March 1991. Our experience to date involves more than 450 patients, and we report here the resultant impact on transfusion practice at our institution. Table 1 shows the average total transfusion requirements per coronary artery bypass graft patient over the past 4 years. This includes primary, redo, elective, and emergency coronary artery bypass grafting. Incidentally, intraoperative autotransfusion was introduced in October 1988. The blood utilization figures for 1991 include 305 patients who did not have plateletpheresis because they were operated on either on an emergency basis, before the introduction of highyield pheresis, or by surgeons not using the technique. Pharmacological reduction of bleeding associated with cardiopulmonary bypass has received much recent attention. The use of antifibrinolytic drugs such as aprotinin holds promise but may prove to be very expensive [2]. A recent study involving 1,480 patients at the Montreal Heart Institute indicated that primary and repeat coronary artery bypass grafting were associated with the use of 5 and 8 units of homologous blood products, respectively [2]. We believe the reduction in our homologous blood product requirements is due
Table 1. Blood Product Ufilization in Coronary Artery Bypass Grafting (including emergency, primary, and repeat procedures) Year 1988 1989 1990 1991 3/91-3/92”
No. of Patients RBC FFP PLT CRYO HBT HBT/case 328 410 467 552 319
5.1 3.8 3.9 1.9 1.6
0.9 0.9 1.4 0.4 0.3
6 9 7 2 0.3
1.6 3.0 0.4 0.02 0.01
4,495 6,929 5,978 2,499 745
13.7 16.9 12.8 4.5 2.3
All patients undergoing coronary artery bypass by the two surgeons using routine plateletpheresis after its introduction in March 1991. CRYO = cryoprecipitate units per case; HBT = total homologous blood FFP = fresh frozen plasma units per or blood product units used; RBC = units of packed red PLT = platelet units per case; case; blood cells per case.
a
1. Davies GG, Wells DG, Mabee TM, Sadler R. Platelet-leukocyte plasmapheresis attenuates the deleterious effects of cardiopulmonary bypass. Ann Thorac Surg 1992;53:274-7. 2. Hardy JF, Desroches J. Natural and synthetic antifibrinolytics in cardiac surgery. Can J Anaesth 1992;39:35?-65.
Preoperative Morphologic and Physiologic Assessment of Internal Thoracic Arteries To the Editor: I read with interest the recent article by Dignan and associates [ l ] regarding the size and reactivity of the internal thoracic artery (ITA) in elderly patients and women. Using a strain-gauge transducer model, they determined that the contractility and sensitivity of ITA smooth muscle to various vasoconstrictors and vasodilators are not different in elderly and female patients. The question asked by Dr Frederick L. Grover of Denver, CO, in the discussion of this article regarding the correlation of ITA reactivity with diabetes and the response of Dr Dignan stating that they did not look for this correlation prompted me to share our experience on this issue. In general, there is a reluctance to use ITA grafts in elderly (greater than 70 years) and diabetic patients because of increased risk of surgical complications and death not infrequently related to sternal infections. Furthermore, it is difficult to discern whether an ITA will provide adequate flow at periods of peak myocardial demand. Therefore, there is a need for a method to preoperatively assess the size and blood flow of an ITA to determine its suitability as a coronary artery bypass graft. We have found that color duplex ultrasound is a reliable noninvasive preoperative imaging modality to evaluate both right and left ITA [2]. This method can accurately define the ITA diameter, the presence of atherosclerosis, and peak systolic and end-diastolic velocities of the ITA. Figure 1 shows the typical ultrasonic appearance of a normal ITA. Based on our experience, an ITA with a diameter greater than 1.8 mm and a peak systolic velocity less than 150 cm/s is acceptable for use as a coronary artery bypass graft. We have also shown that anatomic and physiologic noninvasive ITA flow measurements are independent of age, sex, presence of diabetes, presence of hypertension, and history of previous open heart operation and do not differ between right and left ITAs in those subgroups [2, 31. Our experience strongly supports the findings of Dignan and associates. We hope that future development of a postoperative surveillance protocol for patients who have already undergone bypass operations will provide a basis for interpreting ITA anatomy and blood flow characteristics and a conceptual frame-
CORRESPONDENCE
Ann Thorac Surg
1992:54:1018-24
assist device seems to be well-suited for long-term ventricular support. With the next generation of this device, a nontethered vented electric pump, such patients will be able to be fully mobile and return to a nearly normal lifestyle.
to the amelioration of cardiopulmonary bypass-induced coagulopathy brought about by the use of prebypass plateletpheresis.
Nelson A. Burton, M D W . Stephen Phillips, M D Quentin Macmanus, M D Edward A . Lefrak, M D
Gerald G. Davies, FFARCSI Douglas G. Wells, FFARACS Richard Sadler, M D Thomas M . Mabee, M D Mitchell Ruffcorn, M D John B. Dooley, M D
3301 Woodburn Rd Suite 301 Annandale, VA 22003
St. Luke’s Regional Heart Center 1228 E Rusholme Davenport, IA 52803
References
Plateletpheresis and Transfusion Practice in Heart Operations To the Editor: In a recent publication (11 we reported that prebypass plateletpheresis reduced the perioperative use of homologous blood products. One criticism of this study was the small number of patients involved. We commenced plateletpheresis in March 1991. Our experience to date involves more than 450 patients, and we report here the resultant impact on transfusion practice at our institution. Table 1 shows the average total transfusion requirements per coronary artery bypass graft patient over the past 4 years. This includes primary, redo, elective, and emergency coronary artery bypass grafting. Incidentally, intraoperative autotransfusion was introduced in October 1988. The blood utilization figures for 1991 include 305 patients who did not have plateletpheresis because they were operated on either on an emergency basis, before the introduction of highyield pheresis, or by surgeons not using the technique. Pharmacological reduction of bleeding associated with cardiopulmonary bypass has received much recent attention. The use of antifibrinolytic drugs such as aprotinin holds promise but may prove to be very expensive [2]. A recent study involving 1,480 patients at the Montreal Heart Institute indicated that primary and repeat coronary artery bypass grafting were associated with the use of 5 and 8 units of homologous blood products, respectively [2]. We believe the reduction in our homologous blood product requirements is due
Table 1. Blood Product Ufilization in Coronary Artery Bypass Grafting (including emergency, primary, and repeat procedures) Year 1988 1989 1990 1991 3/91-3/92”
No. of Patients RBC FFP PLT CRYO HBT HBT/case 328 410 467 552 319
5.1 3.8 3.9 1.9 1.6
0.9 0.9 1.4 0.4 0.3
6 9 7 2 0.3
1.6 3.0 0.4 0.02 0.01
4,495 6,929 5,978 2,499 745
13.7 16.9 12.8 4.5 2.3
All patients undergoing coronary artery bypass by the two surgeons using routine plateletpheresis after its introduction in March 1991. CRYO = cryoprecipitate units per case; HBT = total homologous blood FFP = fresh frozen plasma units per or blood product units used; RBC = units of packed red PLT = platelet units per case; case; blood cells per case.
a
1. Davies GG, Wells DG, Mabee TM, Sadler R. Platelet-leukocyte plasmapheresis attenuates the deleterious effects of cardiopulmonary bypass. Ann Thorac Surg 1992;53:274-7. 2. Hardy JF, Desroches J. Natural and synthetic antifibrinolytics in cardiac surgery. Can J Anaesth 1992;39:35?-65.
Preoperative Morphologic and Physiologic Assessment of Internal Thoracic Arteries To the Editor: I read with interest the recent article by Dignan and associates [ l ] regarding the size and reactivity of the internal thoracic artery (ITA) in elderly patients and women. Using a strain-gauge transducer model, they determined that the contractility and sensitivity of ITA smooth muscle to various vasoconstrictors and vasodilators are not different in elderly and female patients. The question asked by Dr Frederick L. Grover of Denver, CO, in the discussion of this article regarding the correlation of ITA reactivity with diabetes and the response of Dr Dignan stating that they did not look for this correlation prompted me to share our experience on this issue. In general, there is a reluctance to use ITA grafts in elderly (greater than 70 years) and diabetic patients because of increased risk of surgical complications and death not infrequently related to sternal infections. Furthermore, it is difficult to discern whether an ITA will provide adequate flow at periods of peak myocardial demand. Therefore, there is a need for a method to preoperatively assess the size and blood flow of an ITA to determine its suitability as a coronary artery bypass graft. We have found that color duplex ultrasound is a reliable noninvasive preoperative imaging modality to evaluate both right and left ITA [2]. This method can accurately define the ITA diameter, the presence of atherosclerosis, and peak systolic and end-diastolic velocities of the ITA. Figure 1 shows the typical ultrasonic appearance of a normal ITA. Based on our experience, an ITA with a diameter greater than 1.8 mm and a peak systolic velocity less than 150 cm/s is acceptable for use as a coronary artery bypass graft. We have also shown that anatomic and physiologic noninvasive ITA flow measurements are independent of age, sex, presence of diabetes, presence of hypertension, and history of previous open heart operation and do not differ between right and left ITAs in those subgroups [2, 31. Our experience strongly supports the findings of Dignan and associates. We hope that future development of a postoperative surveillance protocol for patients who have already undergone bypass operations will provide a basis for interpreting ITA anatomy and blood flow characteristics and a conceptual frame-
