Ann Thorac Surg 2004;77:1819-1821
© 2004 The Society of Thoracic Surgeons
Case report
Coronary artery bypass grafting in an immune thrombocytopenic purpura patient using off-pump techniques
Yoichi Inoue, MDa*,
Remy C. H. Lim, MB, ChBa,
Parma Nand, FRACSa
a Cardiothoracic Surgical Unit, Green Lane Hospital, Auckland, New Zealand
Accepted for publication June 3, 2003.
* Address reprint requests to Dr Inoue, Cardiothoracic Surgical Unit, Green Lane Hospital, Green Lane Rd, West Auckland 3, New Zealand.
e-mail: yoichii{at}adhb.govt.nz
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Abstract
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We performed an off-pump coronary artery bypass grafting (OPCABG) procedure on a 60-year-old woman with idiopathic thrombocytopenic purpura (ITP) whose platelet count was 42 x 103 per microliter on admission. She was treated with immunoglobulin G (IgG) (0.5 g · kg–1 · d–1) for 4 days, resulting in a platelet count rise to 187 x 103 per microliter. She subsequently underwent an uneventful OPCABG procedure without requiring any blood transfusions. The combination of OPCABG and preoperative IgG therapy appears to be an ideal strategy for ITP patients requiring coronary revascularization.
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Introduction
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Platelet consumption and dysfunction are common sequelae of cardiopulmonary bypass (CPB) techniques among a whole array of potential complications. Resultant bleeding diathesis compounded by an accompanying cascade of coagulopathy can become a major perioperative concern, culminating in significant transfusion and reexploration. None of these are free of problems; moreover, the costs of the whole procedure are dramatically increased with the use of blood products [1].
Off-pump coronary artery bypass grafting (OPCABG) has been shown to be associated with less platelet consumption, perioperative blood loss, and therefore transfusion requirements. On the other hand, CPB has been shown to contribute to platelet dysfunction because the extracorporeal circuit induces the contact activation of platelets and creates shear stress in flowing blood [2].
Idiopathic thrombocytopenic purpura (ITP) is primarily a disorder of increased platelet destruction mediated by autoantibodies to platelet-membrane antigens. The literature on patients undergoing cardiac operations is scarce. The OPCABG technique combined with preoperative immunoglobulin G (IgG) therapy may be an appropriate strategy for these patients.
A 60-year-old woman presented to our institution with New York Heart Association class III angina and breathlessness. Her coronary angiography showed severe stenosis in the proximal left anterior descending artery and moderate stenosis in the circumflex and occluded right coronary artery. She had a history of ITP for 6 years and ulcerative colitis treated with nonsteroidal medication. Her ITP to date had been managed expectantly, with platelet counts between 40 x 103 and 60 x 103 per microliter (standard level, 150 x 103 to 400 x 103 per microliter). She was referred for surgical revascularization after a coronary angiogram. However, her ITP status was of obvious concern. A hematologist's recommendation was that she have preoperative IgG therapy if her platelet count were less than 100 x 103 per microliter. Her platelet count was 42 x 103 per microliter on admission. She was therefore commenced on 34 mg/d (0.5 g · kg–1 · d–1) of IgG for 4 days. This resulted in a platelet count raised to 187 x 103 per microliter. Her preoperative hemoglobin level was 13.5 g/dL. She subsequently underwent an OPCABG procedure, receiving three grafts, including left internal thoracic artery to anterior descending artery and saphenous vein grafts to the obtuse marginal and distal right coronary arteries, using the Octopus 4 stabilizing system (Medtronic, Inc, Minneapolis, MN). The left radial artery was not used because of its small caliber. Before grafting, heparin (100 IU/kg) was administered to achieve an activated clotting time of more than 300 seconds, which was reversed with protamine at the end of the anastomoses. At the end of the procedure, her platelet count was 163 x 103 per microliter, and her hemoglobin level was 9.0 g/dL. Operative and postoperative bleeding was minimal, and her total drainage was only 320 mL. On the first postoperative day, her hemoglobin level was 9.7 g/dL, and her platelet count was 202 x 103 per microliter. No packed red cells or other blood products, including fresh frozen plasma or platelets, were necessary during her perioperative course. Her platelet count remained at more than 200 x 103 per microliter until her discharge on the fifth postoperative day.
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Comment
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Improved stabilizing devices have contributed to the performance of an increased number of OPCABG procedures. The technique has comparable graft patency and reduced morbidity and mortality compared with conventional coronary artery bypass grafting (CABG). This difference is most obvious in high-risk patients [1, 3]. A similar trend has been noted at our institution, where approximately 20% of procedures are performed using OPCABG techniques. One of the benefits of using OPCABG rather than conventional CABG has been the significant reductions in blood loss and the transfusion of platelets and other blood products [4]. These may be attributed to the detrimental effects of CPB on the coagulation cascade: platelet aggregation, consumption, and dysfunction [2, 5]. Hence, the use of CPB techniques in patients with preexisting hematologic disorders, including ITP, inherited thrombocytopenia, and von Willibrand disease, has the potential to wreak havoc on patients' coagulation status. The literature on CABG in ITP patients is scarce. Mathew and colleagues [6] summarized eight previously reported cases of CABG in ITP patients and three of their own cases. In the eight cases reported by others in their summary, the patients underwent preoperative splenectomies. Prophylactic splenectomy in the presence of significant coronary artery disease obviously is associated with an increased perioperative risk for cardiac morbidity and mortality and thus may not be the safest option. As reported, glucocorticoids are sometimes used to treat ITP, but this also carries significant risk for perioperative morbidity and should thus be avoided if possible. Mathew and colleagues' own 3 patients were successfully operated on with only preoperative IgG therapy, thus avoiding splenectomies and perioperative glucocorticoids. Two of these 3 patients, however, needed intraoperative platelet transfusions because of marked thrombocytopenia after CPB. Ohno and colleagues [7] also reported a similar case in which the patient needed an intraoperative platelet transfusion despite a preoperative improvement in the platelet count of 110 x 103 per microliter with IgG therapy. Our patient, on the other hand, having undergone OPCABG, did not require any platelet transfusion during the course of the perioperative period after IgG therapy. Her platelet count was 202 x 103 per microliter and 284 x 103 per microliter on postoperative days 1 and 3, respectively.
Preoperative IgG therapy has been reported to increase platelet counts 5 to 7 days after administration. Platelet counts return to pretreatment levels within 1 month [8]. IgG therapy has been postulated to (1) decrease autoantibody synthesis, (2) protect platelets or megakaryocytes from platelet antibodies, and (3) block the reticuloendothelial Fc receptor [8], thus explaining persistent postoperative increases in platelet counts.
By avoiding use of an extracorporeal circuit, platelet dysfunction is minimized. Furthermore, preoperative IgG therapy eliminates the need for prophylactic splenectomy or glucocorticoid administration. We believe that the OPCABG technique combined with preoperative IgG therapy can be performed safely in ITP patients, without the need for blood product transfusions. Therefore, we recommend this as the preferred strategy for all ITP patients who require coronary revascularization.
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References
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- Kshettry V.R., Flavin T.F., Emery R.W., et al. Does multivessel, off-pump coronary artery bypass reduce postoperative morbidity?. Ann Thorac Surg 2000;69:725-731.
- Kawahito K., Kobayashi E., Iwasa H., et al. Platelet aggregation during cardiopulmonary bypass evaluated by a laser light scattering. Ann Thorac Surg 1999;67:79-84.[Abstract/Free Full Text]
- Mack M., Bachand D., Acuff T., et al. Improvement outcomes in coronary artery bypass grafting with beating-heart techniques. J Thorac Cardiovasc Surg 2002;124:598-607.[Abstract/Free Full Text]
- Ascoine R., Williams S.W., Lloyd C.T., et al. Reduced postoperative blood loss and transfusion requirement after beating-heart coronary operations: a prospective randomised study. J Thorac Cardiovasc Surg 2001;121:689-696.[Abstract/Free Full Text]
- Muriithi E.W., Belcher P.R., Rao J.N., et al. The effect of heparin and extracorporeal circulation on platelet counts and platelet microaggregation during cardiopulmonary bypass. J Thorac Cardiovasc Surg 2000;120:538-543.[Abstract/Free Full Text]
- Mathew T.C., Vasudevan R., Leb L., et al. Coronary artery bypass grafting in immune thrombocytopenic purpura. Ann Thorac Surg 1997;64:1059-1062.[Abstract/Free Full Text]
- Ohno H., Higashidate M., Yokosuka T. Washing of the residual solution of cardiopulmonary bypass circuit after coronary artery bypass grafting in idiopathic thrombocytopenic purpura. J Cardiovasc Surg (Torino) 2002;43(2):185-188.[Medline]
- Koyanagi T., Kyo S., Hirooka E., et al. Redo without transfusion in a patient with idiopathic thrombocytopenic purpura. Ann Thorac Surg 2000;69:1261-1263.[Abstract/Free Full Text]
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Abstract
Introduction
