Emergency thromboembolectomy for a massive saddle embolism crossing an atrial septal defect
KeywordsAtrial Septal Defect Decompressive Craniectomy Inferior Vena Cava Filter Hemorrhagic Transformation Coronary Perfusion Pressure
Acute ischemic stroke is often complicated by hemorrhagic transformation that may preclude pharmacologic venous thromboembolic prophylaxis.1 The risk of thrombotic complications after acute stroke in the absence of pharmacologic prophylaxis is substantial, with the incidence of deep venous thrombosis reported at 50% and that of clinically apparent pulmonary embolism at 10-13%.2,3
Massive pulmonary embolus requiring open thromboembolectomy is rare, typically limited to those with absolute contraindications to lytic therapy (i.e., recent intracranial hemorrhage). In this case, the patient had a very large thrombus at heightened risk for paradoxical embolization given the presence of an atrial septal defect. After consultation with our colleagues in neurological surgery, neurology, vascular medicine, and cardiovascular surgery, the benefits of open thromboembolectomy were deemed to outweigh the potential risk of recurrent intracranial hemorrhage associated with the systemic administration of unfractionated heparin for cardiopulmonary bypass.
Optimal perioperative hemodynamic management during open pulmonary thromboembolectomy is critical for maximizing the chances of a positive outcome. Anesthetic goals are centered on support of the failing right ventricle, including maintaining systemic vascular resistance and coronary perfusion pressure, supporting ventricular inotropy and the heart rate, and minimizing additional increases in pulmonary vascular resistance.4 In this case, meticulous titration of intravenous epinephrine, norepinephrine, and vasopressin along with judicious fluid administration and avoidance of hypoxemia and hypercarbia during induction and maintenance of anesthesia resulted in adequate hemodynamic stability. Fortunately, this patient improved rapidly following thromboembolectomy and suffered no bleeding complications associated with systemic heparinization. An infrarenal inferior vena cava filter was placed on postoperative day 1 to prevent recurrent thromboembolic episodes. She was discharged home on postoperative day 6.
Financial support & conflicts of interests
This submission was handled by Dr. Hilary P. Grocott, Editor-in-Chief, Canadian Journal of Anesthesia.
VIDEO Transesophageal echocardiogram of a massive saddle pulmonary embolus that can also been seen crossing the interatrial septum. (AVI 3661 kb)