CRP20.Acute Post-Operative Thrombosis of a Magnetically Levitated Left Ventricular Assist Device Requiring Emergent Pump Exchange
Presented During: AATS Cardiothoracic Resident Case Report-Poster Display
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Madeline Fryer is a resident in the Integrated Cardiothoracic Surgery program at the University of Rochester. She is an alumna of the University of Massachusetts Medical School and earned a Master of Medical Science in immunology from Harvard Medical School. Her primary interest is adult cardiac surgery with a particular focus on heart failure.
Saturday, May 6, 2023: 5:00 PM - Tuesday, May 9, 2023: 5:00 PM
Los Angeles Convention Center
Room: ePoster Area, Exhibit Hall
Description
Introduction: Left ventricular assist devices (LVAD) are life-prolonging therapy for end stage heart failure. Risks of these devices include thrombosis and stroke, but few cases of acute perioperative pump thrombosis have been reported. Here, we describe a case of pump thrombosis at time of index operation requiring emergent pump exchange.
Case Summary: A 57-year-old woman with history of non-ischemic cardiomyopathy, acute on chronic systolic heart failure with inotrope dependence, and factor V Leiden heterozygosity underwent LVAD implantation via bilateral thoracotomies. The case was performed without initiating cardiopulmonary bypass and no intra-operative complications were initially encountered. According to pre-operative hematology recommendations, surgery was performed using our standard anticoagulation protocol and heparin was reversed at case conclusion. The LVAD was set to 5400 RPM and flowing 4.4 LPM.
A dramatic decrease in calculated LVAD flows occurred just prior to transport, prompting a ramp transthoracic echo. Speeds were increased to 7000 RPM without any resulting change in flow, hemodynamics, or left ventricular end diastolic diameter. The decision was made to re-open. Epicardial echo demonstrated thrombotic burden within the outflow graft, confirming acute pump thrombosis. The patient underwent immediate CT angiography which showed no evidence of large vessel occlusion or major cerebrovascular accident. The patient returned to the operating room for emergent LVAD pump exchange. Heparin was not reversed and the patient underwent delayed closure two days later. The patient's overall course was complicated by frontal lobe stroke, gastrointestinal bleeding, and left thoracotomy infection. She made an excellent functional recovery and was discharged home 54 days after implantation.
Discussion: Among the possible etiologies for post-operative LVAD low-flow, pump thrombosis is one of the most difficult to manage. Diagnosis can be made by assessing the patient's hemodynamic monitoring, chest tube output, LVAD parameters, and echocardiography. Once the diagnosis is made, it is critical to rule out thromboembolic events to large vessels in the brain amenable to endovascular retrieval in order to mitigate major neurologic injury. The presence of infarcted brain may also influence management decisions and risk stratification of hemorrhagic conversion with anticoagulation.
The patient was hemodynamically stable with significant vasopressor support, allowing for diagnostic work-up and return to the operating room without initiating extracorporeal membrane oxygenation (ECMO). Had she decompensated further, this would have been the next intervention as a bridge to pump exchange. Post-operative anticoagulation was aggressively managed in collaboration with hematology. Systemic heparin was not reversed after the pump exchange and the patient was maintained on therapeutic anticoagulation.
Conclusion: Acute pump thrombosis is a rare but potentially catastrophic event following LVAD implantation. Although the only device currently available has an improved hemocompatibility profile compared to earlier pumps, it is important to maintain acute pump thrombosis in the differential. A high index of suspicion and expeditious management are critical to successful patient outcome. Thrombolytic therapy is contraindicated in the acute post-operative period, and ECMO may be indicated for temporary support.
Case Summary: A 57-year-old woman with history of non-ischemic cardiomyopathy, acute on chronic systolic heart failure with inotrope dependence, and factor V Leiden heterozygosity underwent LVAD implantation via bilateral thoracotomies. The case was performed without initiating cardiopulmonary bypass and no intra-operative complications were initially encountered. According to pre-operative hematology recommendations, surgery was performed using our standard anticoagulation protocol and heparin was reversed at case conclusion. The LVAD was set to 5400 RPM and flowing 4.4 LPM.
A dramatic decrease in calculated LVAD flows occurred just prior to transport, prompting a ramp transthoracic echo. Speeds were increased to 7000 RPM without any resulting change in flow, hemodynamics, or left ventricular end diastolic diameter. The decision was made to re-open. Epicardial echo demonstrated thrombotic burden within the outflow graft, confirming acute pump thrombosis. The patient underwent immediate CT angiography which showed no evidence of large vessel occlusion or major cerebrovascular accident. The patient returned to the operating room for emergent LVAD pump exchange. Heparin was not reversed and the patient underwent delayed closure two days later. The patient's overall course was complicated by frontal lobe stroke, gastrointestinal bleeding, and left thoracotomy infection. She made an excellent functional recovery and was discharged home 54 days after implantation.
Discussion: Among the possible etiologies for post-operative LVAD low-flow, pump thrombosis is one of the most difficult to manage. Diagnosis can be made by assessing the patient's hemodynamic monitoring, chest tube output, LVAD parameters, and echocardiography. Once the diagnosis is made, it is critical to rule out thromboembolic events to large vessels in the brain amenable to endovascular retrieval in order to mitigate major neurologic injury. The presence of infarcted brain may also influence management decisions and risk stratification of hemorrhagic conversion with anticoagulation.
The patient was hemodynamically stable with significant vasopressor support, allowing for diagnostic work-up and return to the operating room without initiating extracorporeal membrane oxygenation (ECMO). Had she decompensated further, this would have been the next intervention as a bridge to pump exchange. Post-operative anticoagulation was aggressively managed in collaboration with hematology. Systemic heparin was not reversed after the pump exchange and the patient was maintained on therapeutic anticoagulation.
Conclusion: Acute pump thrombosis is a rare but potentially catastrophic event following LVAD implantation. Although the only device currently available has an improved hemocompatibility profile compared to earlier pumps, it is important to maintain acute pump thrombosis in the differential. A high index of suspicion and expeditious management are critical to successful patient outcome. Thrombolytic therapy is contraindicated in the acute post-operative period, and ECMO may be indicated for temporary support.