THROMBECTOMY FOR ACUTE EMBOLIC STROKE FOLLOWING HEART SURGERY

Abstract

Introduction Acute ischaemic stroke occurs in approximately 1-10% of patients undergoing cardiac surgery and can markedly impair recovery (1). Thrombolysis carries an unacceptably high risk of haemorrhage in the early postoperative period after heart surgery. Mechanical thrombectomy is becoming an increasingly preferred alternative to treat ischaemic strokes, and unlike thrombolysis, is not contraindicated in the early postoperative period. We report a patient who had witnessed onset of ischaemic stroke in the early postoperative period after aortic valve replacement (AVR) and coronary artery bypass grafting (CABG) surgery and was treated with mechanical thrombectomy. Discussion An 81-year-old male patient underwent elective tissue AVR and CABG (internal mammary to left anterior descending coronary artery) surgery. Surgery was uncomplicated and following weaning from mechanical ventilation, the patient's trachea was extubated on the evening of surgery. His recovery progressed uneventfully and on the day after surgery, he was moved to a high dependency unit. On the morning of the second post-operative day, the patient had a witnessed rapid deterioration in conscious level, becoming unresponsive with a divergent gaze. Urgent plain CT scan of the brain showed hyperattenuation of the left middle cerebral artery (MCA) territory consistent with acute thrombosis. The patient was granted emergency funding for a mechanical thrombectomy and was transported to the regional neurology hospital. A mechanical thrombectomy was performed successfully, with digital subtraction angiography (DSA) confirming complete occlusion of the left MCA with poor collateral cross flow. The patient failed to recover neurological function and died approximately 24 hours later. Mechanical thrombectomy is now a well-established treatment for acute ischaemic stroke. There are clear advantages with regard to functional outcome for patients undergoing mechanical thrombectomy versus best available medical therapies such as thrombolysis (2). A recent systematic review of acute ischaemic stroke post cardiac surgery showed that 50% of patients who underwent endovascular mechanical thrombectomy had a full or good neurological recovery, 36% had moderate recovery and 14% had little improvement (1). Factors that may have led to a poor outcome in this patient's case included the delay in hospital transfer, the poor cerebral cross blood flow noted on DSA and extensive comorbidities. In conclusion, although there are many reports of mechanical thrombectomy being associated with a good neurological outcome from acute ischaemic stroke associated with cardiac surgery, outcome may not be improved if there is underlying cerebrovascular disease and intervention is delayed.