|Year : 2019 | Volume
| Issue : 1 | Page : 60-62
Graft thrombosis after off-pump coronary artery bypass grafting: Postoperative challenges and implications
Rohan Magoon1, Sambhunath Das1, Ameya Karanjkar1, Milind P Hote2
1 Department of Cardiac Anaesthesia, Cardiothoracic Centre, All India Institute of Medical Sciences, New Delhi, India
2 Department of Cardiothoracic Vascular Surgery, Cardiothoracic Centre, All India Institute of Medical Sciences, New Delhi, India
|Date of Web Publication||2-May-2019|
Dr. Sambhunath Das
Department of Cardiac Anaesthesia, Room No. 7, 7th Floor, Cardiothoracic Centre, All India Institute of Medical Sciences, Ansari Nagar, New Delhi - 110 029
Source of Support: None, Conflict of Interest: None
Perioperative graft failure is an important cause of myocardial ischemia following coronary artery bypass grafting. Early diagnosis of graft thrombosis is of paramount importance for limiting the sequelae of postoperative myocardial infarction (PMI). We present a case of PMI following off-pump coronary artery bypass grafting resulting from saphenous venous graft thrombosis.
Keywords: Graft thrombosis, heparin, off-pump coronary artery bypass grafting, postoperative myocardial infarction, re-revascularization
|How to cite this article:|
Magoon R, Das S, Karanjkar A, Hote MP. Graft thrombosis after off-pump coronary artery bypass grafting: Postoperative challenges and implications. J Pract Cardiovasc Sci 2019;5:60-2
|How to cite this URL:|
Magoon R, Das S, Karanjkar A, Hote MP. Graft thrombosis after off-pump coronary artery bypass grafting: Postoperative challenges and implications. J Pract Cardiovasc Sci [serial online] 2019 [cited 2020 May 29];5:60-2. Available from: http://www.j-pcs.org/text.asp?2019/5/1/60/257606
| Introduction|| |
Graft failure after coronary artery bypass grafting (CABG) is a devastating complication which if untreated may lead to myocardial ischemia and infarction. Percutaneous coronary intervention, surgical graft revision, and conservative medical intensive care unit management are used for treatment. However, the best treatment is currently unknown. We describe a case of graft thrombosis after off-pump coronary artery bypass grafting (OPCAB) surgery creating postoperative challenges to manage the stormy course. The patient could not be revived in spite all possible interventions.
| Case Report|| |
A 62-year-old female underwent OPCAB with left internal mammary artery to left anterior descending artery anastomosis and saphenous venous graft to obtuse marginal (OM) and distal right coronary artery (d-RCA). Intraoperative echocardiography revealed a good biventricular function on minimal support of nitroglycerin 0.5 μg/kg/min and dobutamine 5 μg/kg/min. Postoperative activated clotting time was 190 s obviating the need of heparin reversal. She was extubated on the subsequent day with reinitiation of aspirin, statin, and nitrate therapy. On the 4th postoperative day, she experienced angina. Electrocardiography (ECG) demonstrated ST-segment elevation in lateral and right-sided leads. Hemodynamics deteriorated with the resultant need for escalating inotropes and instituting intra-aortic balloon pump (IABP) support. Airway was secured by endotracheal intubation and she was mechanically ventilated. Troponin I assay was performed which was grossly elevated. Transthoracic echocardiography depicted inferoseptal hypokinesia.
Considering a strong suspicion of graft thrombosis, heparin infusion was initiated. In the absence of improvement in angina, ECG, and hemodynamic profile, she was taken up for an emergency surgery ahead of diagnostic modality such as angiography. Intraoperatively, digital palpation revealed lack of pulsatility in d-RCA graft and weak pulsations in OM graft with poor distal flow. Grafts were longitudinally incised to perform thrombectomy and revised by secondary (re-revascularization). However, the patient demonstrated only a mild hemodynamic improvement for 12 h. Patient suffered a cardiac arrest due to ventricular fibrillation and could not be successfully revived despite intensive cardiopulmonary resuscitation and IABP support.
| Discussion|| |
Graft thrombosis within a month of revascularization has been reported in as high as 10%–15% of cases in an angiographic follow-up study. Increased rate of graft thrombosis with OPCAB has been demonstrated by a recent study as compared to on-pump grafting. However, many other studies do not support a similar finding. Irrespective of off-pump or on-pump grafting, a procoagulant milieu should be avoided postoperatively. Inherently, weak antithrombotic property of venous grafts and high-pressure distension contribute to graft attrition which can initiate the thrombus formation cascade. Following initiation of the cascade, a hypercoagulable environment provokes increasing concerns about graft thrombosis in the background of endothelial damage. Patients with factor V Leiden mutation are reported to have 45% venous graft occlusion rate after CABG. Judicious transfusion of blood and blood products such as platelet concentrates, fresh frozen plasma, and cryoprecipitate; avoidance of prophylactic antifibrinolytics; and early reinstitution of aspirin therapy constitute the major efforts aimed at alleviating postoperative hypercoagulability [Table 1].
A comprehensive strategy should be followed for managing suspected graft failure. Rasmussen et al. presented the feasibility results of acute angiography and revascularization for the management of early postoperative graft failure. They concluded that immediate reangiography demonstrated graft thrombosis as a major cause of incomplete revascularization in a majority of the patients. The subjects with a circulatory collapse were taken up for an immediate reoperation without preceding angiography, as in the index case. Reoperation for re-revascularization implied a low risk in their setting. However, mortality in the present case despite an early revascularization could be attributed to an increased tendency of postoperative graft thrombosis resulting from a possible genetic predisposition or an underlying systemic disorder; promoting prothrombotic environment. Moreover, a poorly augmented graft flow due to compromised pressure head compounds the situation furthermore.
| Conclusion|| |
The authors wish to elucidate graft thrombosis as an important cause of postoperative myocardial infarction, leading to mortality following CABG. Various graft related factors such as inappropriate length, tortuous lie or position, endothelial injury and blood flow pattern through the conduit are the important determinants of thrombosis. Delayed resumption of anti-thrombotic therapy, use of pro-thrombotic medications, excessive blood transfusion and prolonged hypotension after CABG surgery in postoperative period play major role for graft thrombosis. Intraoperative graft flow assessment with transit time flowmetry and meticulous postoperative management protocols can ensure an improved graft function following coronary artery revascularization.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
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Conflicts of interest
There are no conflicts of interest.
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