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Antifibrinolytic therapy during OPCAB surgery: A word of caution
LETTERS TO THE EDITOR
Acute Pulmonary Edema Complicating Percutaneous Balloon Valvuloplasty for Pulmonic Stenosis To the Editor I read with interest the case report of acute pulmonary edema after percutaneous balloon valvuloplasty for congenital pulmonic stenosis in a 66-year-old man.1 Such a complication is extremely rare. In the world’s largest series of percutaneous balloon pulmonic valvuloplasty for pulmonic stenosis in 53 adolescent and adult patients (age range, 13 to 55 years), reported from China,2 no such complication was reported. The pathogenetic mechanism of acute pulmonary edema, which is due to a sudden increase in pulmonic blood flow after balloon dilation of the stenotic pulmonic valve, is reminiscent of congestive heart failure after the palliative construction of too large a systemic-to-pulmonary shunt— either the Potts procedure3 (descending aorta-to-left pulmonary artery anastomosis) or the Waterston procedure4 (ascending aorta-to-right pulmonary artery anastomosis)—in children with tetralogy of Fallot. Congestive heart failure was one of the most dreaded complications of the shunting procedures to which the patients often succumbed. With the advent of primary total corrective repair of tetralogy of Fallot in early childhood, these types of palliative operations are no longer performed. This rare complication reported by Walker et al1 is another reason why balloon treatment of pulmonic stenosis should be performed in early childhood rather than in late adulthood. The longer the pulmonary vascular bed is underperfused because of pulmonic stenosis, the less adaptable it is to a sudden rise in pulmonary blood flow after abrupt dilation of a long-standing stenosis of the pulmonic valve. The only other similar report of acute pulmonary edema complicating surgical, rather than percutaneous balloon, valvuloplasty was in a 16-year-old girl.5 That child had coexisting tight mitral stenosis, which was unsuspected preoperatively because the decreased pulmonary arterial flow caused by pulmonic stenosis obscured the obstruction to pulmonary venous return caused by the stenotic mitral valve. Tsung O. Cheng, MD Department of Medicine George Washington University Medical Center Washington, DC REFERENCES 1. Walker CPR, Bateman CJ, Rigby ML, Brookes CIO: Acute pulmonary edema after percutaneous balloon valvuloplasty for pulmonary valve stenosis. J Cardiothorac Vasc Anesth 15:480-482, 2001 2. Chen C-R, Cheng TO, Huang T, et al: Percutaneous balloon valvuloplasty for pulmonic stenosis in adolescents and adults. N Engl J Med 335:21-25, 1996 3. Potts WJ, Smith S, Gibson S: Anastomosis of the aorta to a pulmonary artery: Certain types in congenital heart disease. JAMA 132:627-631, 1946 4. Waterston DJ, Stark J, Ashcraft KW: Ascending aorta-to-right pulmonary artery shunts: Experience with 100 patients. Surgery 72:897-904, 1972 5. Matisonn RE, Mitha AS, Williams MA, Chesler E: Pulmonary edema following pulmonary valvulotomy. Ann Thorac Surg 20:581-585, 1975 doi: 10.1053/jcan.2002.124157
Antifibrinolytic Therapy During OPCAB Surgery: A Word of Caution To the Editor Several articles in the cardiothoracic literature have alluded to the use of antifibrinolytic therapy in off-pump coronary artery bypass graft (OPCAB) surgery.1,2 The fundamental issues among surgeons who perform most of their coronary cases using beating-heart techniques is not whether complete revascularization is feasible, which it is, but rather the amount of blood loss during the procedure. Despite careful and methodical use of a cell saver during these procedures, the amount of bleeding correlates to the number of grafts performed and to the length of the procedure. Hemorrhagic complications and the need for allogenic transfusions are still major problems after OPCAB surgery. We have shown that 43% of OPCAB surgery patients require transfusion of packed red blood cells in the perioperative period. Overall, Journal of Cardiothoracic and Vascular Anesthesia, Vol 16, No 3 (June), 2002: pp 391-394
391
392
LETTERS TO THE EDITOR
OPCAB surgery patients receive 0.6 U of packed red blood cells in the perioperative period. This number increases to 0.8 U when the number of grafted targets is ⬎4 and to 1 U with complete arterial revascularization. Because there are many reports regarding decreased use of red blood cell transfusions with OPCAB surgery,3 we studied the impact of antiplatelet therapy and heparinization protocols on blood transfusion during OPCAB surgery. This survey sent to cardiac surgeons in the United States showed that heparinization standards are lacking for OPCAB surgery.4 Of surgeons, 28% administer full-dose heparin, 54% administer half-dose heparin, and 13% administer one-third dose heparin during OPCAB surgery. In addition, 10% attempt to maintain activated coagulation time (ACT) at ⬎400 seconds, and 70% attempt to maintain ACT between 300 and 400 seconds. Despite a wide range of heparinization protocols during OPCAB surgery, 84% of surgeons surveyed believed that partial heparinization is associated with less intraoperative bleeding during OPCAB surgery. This belief has not been borne out in the large number of patients who have undergone OPCAB surgery in our institution since 1996.5 Antifibrinolytic therapy has been successful in reducing transfusion rates in traditional coronary artery bypass graft surgery using cardiopulmonary bypass and has been proposed to decrease transfusion rates during OPCAB surgery.2 A double-blinded study has shown that the use of antifibrinolytic therapy not only lowers postoperative bleeding and the need for allogenic blood product transfusions, but also reduces the inflammatory response as shown by lower postoperative D-dimer levels.2 Most importantly, this study showed the safety of using antifibrinolytic therapy in OPCAB surgery—that is, the lack of thrombotic complications. While maintaining ACT at ⬎250 seconds, the authors showed no thrombotic complications of coronary vessels by electrocardiogram and enzyme analysis. The conclusions of this study are limited, however, because it is theoretically possible to have no hemodynamic consequence, electrocardiogram change, or enzyme elevations with graft thrombosis after coronary artery bypass graft surgery of occluded vessels.6 Although we support novel methods to reduce the amount of intraoperative blood loss during OPCAB surgery, we offer a word of caution. In an attempt to reduce intraoperative blood loss during OPCAB surgery, we used half-dose aprotinin in 3 patients. Full-dose heparinization was used and ACT was maintained at ⬎500 seconds in all patients. Despite these ACT levels, acute thrombosis of all grafts was noted in all patients after reversal with protamine. Graft flows were excellent based on 3 criteria before protamine reversal using the transit time flow measurement technique with good diastolic flow patterns, normal pulsatility index (⬍5), and absolute values ⬎15 mL/min in all grafts.7 After protamine reversal, all grafts were occluded in these patients. This is strong evidence to suggest that a hypercoagulable state exists in patients undergoing OPCAB surgery and that graft thrombosis is possible with the use of aprotinin. We revised all grafts in all patients after the readministration of full-dose heparin. Thrombus was found at the sites of coronary anastomoses in all grafts without other technical problems. After graft revision, all 3 criteria for graft patency were met by transit time flow measurement for all grafts. There were no untoward complications in the patients. Until antifibrinolytic therapy is studied further in laboratory animals undergoing OPCAB surgery, we recommend caution in its routine use in patients undergoing OPCAB surgery. Harry W. Donias, MD Raffy L. Karamanoukian, MD Hratch L. Karamanoukian, MD Department of Surgery and Division of Cardiothoracic Surgery State University of New York at Buffalo Buffalo, NY Department of Surgery University of San Diego San Diego, CA REFERENCES 1. Mariani MA, Gu YJ, Boonstra PW, et al: Procoagulant activity after off-pump coronary operations: Is the current anticoagulation adequate? Ann Thorac Surg 67:1370-1375, 1999 2. Casati V, Gerli C, Franco A, et al: Tranexamic acid in off-pump coronary surgery: A preliminary, randomized, double-blind, placebocontrolled study. Ann Thorac Surg 72:470-475, 2001 3. Nader ND: The use of blood products in off-pump coronary artery bypass grafting, in Salerno TA, Ricci MR, Karamanoukian HL, et al (eds): Beating Heart Coronary Artery Surgery. Armonk, NY, Futura Publishing Company, 2001, pp 81-88 4. D’Ancona G, Donias HW, Karamanoukian RL, et al: OPCAB (Off Pump Clopidogrel Aspirin or Both) Therapy Survey. Heart Surg Forum. 4:354-358, 2001
5. Kawaguchi AT, Karamanoukian HL, Spanu I, et al: OPCAB in reoperative myocardial revascularization: Intermediate-term outcomes. Fourth Annual Meeting, International Society for Minimally Invasive Cardiac Surgery, Munich, Germany, 2001 6. Ricci M, Karamanoukian HL, Salerno TA, et al: The role of coronary graft flow measurement during reoperations for early graft failure following off-pump coronary revascularization. J Card Surg 14:342-347, 1999 7. D’Ancona G, Karamanoukian HL, Ricci M, et al: Graft revision after transit time flow measurement in off-pump coronary artery bypass grafting. Eur J Cardiothorac Surg 17:287-293, 2000 doi: 10.1053/jcan.2002.124158
Acute Pulmonary Edema Complicating Percutaneous Balloon Valvuloplasty for Pulmonic Stenosis To the Editor I read with interest the case report of acute pulmonary edema after percutaneous balloon valvuloplasty for congenital pulmonic stenosis in a 66-year-old man.1 Such a complication is extremely rare. In the world’s largest series of percutaneous balloon pulmonic valvuloplasty for pulmonic stenosis in 53 adolescent and adult patients (age range, 13 to 55 years), reported from China,2 no such complication was reported. The pathogenetic mechanism of acute pulmonary edema, which is due to a sudden increase in pulmonic blood flow after balloon dilation of the stenotic pulmonic valve, is reminiscent of congestive heart failure after the palliative construction of too large a systemic-to-pulmonary shunt— either the Potts procedure3 (descending aorta-to-left pulmonary artery anastomosis) or the Waterston procedure4 (ascending aorta-to-right pulmonary artery anastomosis)—in children with tetralogy of Fallot. Congestive heart failure was one of the most dreaded complications of the shunting procedures to which the patients often succumbed. With the advent of primary total corrective repair of tetralogy of Fallot in early childhood, these types of palliative operations are no longer performed. This rare complication reported by Walker et al1 is another reason why balloon treatment of pulmonic stenosis should be performed in early childhood rather than in late adulthood. The longer the pulmonary vascular bed is underperfused because of pulmonic stenosis, the less adaptable it is to a sudden rise in pulmonary blood flow after abrupt dilation of a long-standing stenosis of the pulmonic valve. The only other similar report of acute pulmonary edema complicating surgical, rather than percutaneous balloon, valvuloplasty was in a 16-year-old girl.5 That child had coexisting tight mitral stenosis, which was unsuspected preoperatively because the decreased pulmonary arterial flow caused by pulmonic stenosis obscured the obstruction to pulmonary venous return caused by the stenotic mitral valve. Tsung O. Cheng, MD Department of Medicine George Washington University Medical Center Washington, DC REFERENCES 1. Walker CPR, Bateman CJ, Rigby ML, Brookes CIO: Acute pulmonary edema after percutaneous balloon valvuloplasty for pulmonary valve stenosis. J Cardiothorac Vasc Anesth 15:480-482, 2001 2. Chen C-R, Cheng TO, Huang T, et al: Percutaneous balloon valvuloplasty for pulmonic stenosis in adolescents and adults. N Engl J Med 335:21-25, 1996 3. Potts WJ, Smith S, Gibson S: Anastomosis of the aorta to a pulmonary artery: Certain types in congenital heart disease. JAMA 132:627-631, 1946 4. Waterston DJ, Stark J, Ashcraft KW: Ascending aorta-to-right pulmonary artery shunts: Experience with 100 patients. Surgery 72:897-904, 1972 5. Matisonn RE, Mitha AS, Williams MA, Chesler E: Pulmonary edema following pulmonary valvulotomy. Ann Thorac Surg 20:581-585, 1975 doi: 10.1053/jcan.2002.124157
Antifibrinolytic Therapy During OPCAB Surgery: A Word of Caution To the Editor Several articles in the cardiothoracic literature have alluded to the use of antifibrinolytic therapy in off-pump coronary artery bypass graft (OPCAB) surgery.1,2 The fundamental issues among surgeons who perform most of their coronary cases using beating-heart techniques is not whether complete revascularization is feasible, which it is, but rather the amount of blood loss during the procedure. Despite careful and methodical use of a cell saver during these procedures, the amount of bleeding correlates to the number of grafts performed and to the length of the procedure. Hemorrhagic complications and the need for allogenic transfusions are still major problems after OPCAB surgery. We have shown that 43% of OPCAB surgery patients require transfusion of packed red blood cells in the perioperative period. Overall, Journal of Cardiothoracic and Vascular Anesthesia, Vol 16, No 3 (June), 2002: pp 391-394
391
392
LETTERS TO THE EDITOR
OPCAB surgery patients receive 0.6 U of packed red blood cells in the perioperative period. This number increases to 0.8 U when the number of grafted targets is ⬎4 and to 1 U with complete arterial revascularization. Because there are many reports regarding decreased use of red blood cell transfusions with OPCAB surgery,3 we studied the impact of antiplatelet therapy and heparinization protocols on blood transfusion during OPCAB surgery. This survey sent to cardiac surgeons in the United States showed that heparinization standards are lacking for OPCAB surgery.4 Of surgeons, 28% administer full-dose heparin, 54% administer half-dose heparin, and 13% administer one-third dose heparin during OPCAB surgery. In addition, 10% attempt to maintain activated coagulation time (ACT) at ⬎400 seconds, and 70% attempt to maintain ACT between 300 and 400 seconds. Despite a wide range of heparinization protocols during OPCAB surgery, 84% of surgeons surveyed believed that partial heparinization is associated with less intraoperative bleeding during OPCAB surgery. This belief has not been borne out in the large number of patients who have undergone OPCAB surgery in our institution since 1996.5 Antifibrinolytic therapy has been successful in reducing transfusion rates in traditional coronary artery bypass graft surgery using cardiopulmonary bypass and has been proposed to decrease transfusion rates during OPCAB surgery.2 A double-blinded study has shown that the use of antifibrinolytic therapy not only lowers postoperative bleeding and the need for allogenic blood product transfusions, but also reduces the inflammatory response as shown by lower postoperative D-dimer levels.2 Most importantly, this study showed the safety of using antifibrinolytic therapy in OPCAB surgery—that is, the lack of thrombotic complications. While maintaining ACT at ⬎250 seconds, the authors showed no thrombotic complications of coronary vessels by electrocardiogram and enzyme analysis. The conclusions of this study are limited, however, because it is theoretically possible to have no hemodynamic consequence, electrocardiogram change, or enzyme elevations with graft thrombosis after coronary artery bypass graft surgery of occluded vessels.6 Although we support novel methods to reduce the amount of intraoperative blood loss during OPCAB surgery, we offer a word of caution. In an attempt to reduce intraoperative blood loss during OPCAB surgery, we used half-dose aprotinin in 3 patients. Full-dose heparinization was used and ACT was maintained at ⬎500 seconds in all patients. Despite these ACT levels, acute thrombosis of all grafts was noted in all patients after reversal with protamine. Graft flows were excellent based on 3 criteria before protamine reversal using the transit time flow measurement technique with good diastolic flow patterns, normal pulsatility index (⬍5), and absolute values ⬎15 mL/min in all grafts.7 After protamine reversal, all grafts were occluded in these patients. This is strong evidence to suggest that a hypercoagulable state exists in patients undergoing OPCAB surgery and that graft thrombosis is possible with the use of aprotinin. We revised all grafts in all patients after the readministration of full-dose heparin. Thrombus was found at the sites of coronary anastomoses in all grafts without other technical problems. After graft revision, all 3 criteria for graft patency were met by transit time flow measurement for all grafts. There were no untoward complications in the patients. Until antifibrinolytic therapy is studied further in laboratory animals undergoing OPCAB surgery, we recommend caution in its routine use in patients undergoing OPCAB surgery. Harry W. Donias, MD Raffy L. Karamanoukian, MD Hratch L. Karamanoukian, MD Department of Surgery and Division of Cardiothoracic Surgery State University of New York at Buffalo Buffalo, NY Department of Surgery University of San Diego San Diego, CA REFERENCES 1. Mariani MA, Gu YJ, Boonstra PW, et al: Procoagulant activity after off-pump coronary operations: Is the current anticoagulation adequate? Ann Thorac Surg 67:1370-1375, 1999 2. Casati V, Gerli C, Franco A, et al: Tranexamic acid in off-pump coronary surgery: A preliminary, randomized, double-blind, placebocontrolled study. Ann Thorac Surg 72:470-475, 2001 3. Nader ND: The use of blood products in off-pump coronary artery bypass grafting, in Salerno TA, Ricci MR, Karamanoukian HL, et al (eds): Beating Heart Coronary Artery Surgery. Armonk, NY, Futura Publishing Company, 2001, pp 81-88 4. D’Ancona G, Donias HW, Karamanoukian RL, et al: OPCAB (Off Pump Clopidogrel Aspirin or Both) Therapy Survey. Heart Surg Forum. 4:354-358, 2001
5. Kawaguchi AT, Karamanoukian HL, Spanu I, et al: OPCAB in reoperative myocardial revascularization: Intermediate-term outcomes. Fourth Annual Meeting, International Society for Minimally Invasive Cardiac Surgery, Munich, Germany, 2001 6. Ricci M, Karamanoukian HL, Salerno TA, et al: The role of coronary graft flow measurement during reoperations for early graft failure following off-pump coronary revascularization. J Card Surg 14:342-347, 1999 7. D’Ancona G, Karamanoukian HL, Ricci M, et al: Graft revision after transit time flow measurement in off-pump coronary artery bypass grafting. Eur J Cardiothorac Surg 17:287-293, 2000 doi: 10.1053/jcan.2002.124158