THIRD TIME'S A CHARM: TREATING PULMONARY EMBOLISM WITH MECHANICAL THROMBECTOMY AFTER TWO FAILED ATTEMPTS WITH THROMBOLYTIC THERAPY

Abstract

TOPIC: Procedures TYPE: Medical Student/Resident Case Reports INTRODUCTION: Pulmonary embolism (PE) can be a life-threatening condition. Massive PE, characterized by hemodynamic instability with signs of shock, comprises 4.5%-10% of all PE cases and has over 50% mortality rate. When medical therapy fails, aspiration thrombectomy is a treatment option for acute massive or submassive PE in patients with hemodynamic compromise or right ventricular (RV) dysfunction (Dopazo et al, 2018). CASE PRESENTATION: A 61-year-old male presented after an episode of syncope, chest pain, and dyspnea. Due to profound hypoxia, he was intubated. ECG as seen in figure 1 was changed from prior. Troponin was 0.80. In the ED, he was placed on norepinephrine and epinephrine due to hypotension. Bedside echocardiogram (ECHO) showed enlarged RV with severely reduced RV systolic function, hypokinetic RV free wall, and apex. The patient subsequently developed pulseless electrical activity (PEA) arrest. Two cycles of CPR were performed to achieve the return of spontaneous circulation. Due to the possibility of PE, weight-based tPA was administered. He had PEA arrest a second time and CPR was done for 9 minutes. A second dose of weight-based tPA was given after which his hemodynamics transiently improved. Epinephrine drip was discontinued, but norepinephrine drip was continued. He was transferred to ICU for monitoring and was placed on a heparin drip. Over the next 12 hours, despite multiple tPA doses, he progressively decompensated with systolic blood pressure to 40mmHg while on norepinephrine. Vasopressin drip was initiated. Lactic acidosis increased from 3.8 to 6.6 mmol/L, creatinine worsened from 1.6 to 4.0 mg/dL, and Hb 12.2 to 8.5 g/dL. CTA for PE confirmed saddle pulmonary embolism with evidence of RV strain with RV/LV ratio 1.1. He was taken emergently for cardiac catheterization on multiple vasopressors. A bilateral pulmonary artery thrombectomy with a T24 Inari catheter was done successfully, with subsequent improvement in hemodynamics. ECHO after the procedure showed improved RV function and RV size reduction. Within 24 hours of the thrombectomy, vasopressors were titrated off and the patient remained hemodynamically stable. DISCUSSION: Though systemic thrombolytic therapy is typically indicated for hemodynamically unstable patients with suspected pulmonary emboli, it was not effective in our patient, despite multiple doses. Catheter-directed therapies for PE can remove obstructive emboli directly, allowing for rapid patient improvement as seen in our case. Furthermore, though it is an invasive strategy, catheter-directed thrombectomy has the potential to offer both short- and long-term benefits over systemic thrombolysis including early recovery, reduced risk of bleeding, pulmonary hypertension, and reversal of RV failure. CONCLUSIONS: Catheter-directed techniques should be considered on a case-by-case basis, especially in patients who do not improve with thrombolysis. REFERENCE #1: 1.Ciampi-Dopazo, Juan José et al. "Aspiration Thrombectomy for Treatment of Acute Massive and Submassive Pulmonary Embolism: Initial Single-Center Prospective Experience.” Journal of vascular and interventional radiology : JVIR vol. 29,1 (2018): 101-106. doi:10.1016/j.jvir.2017.08.010 REFERENCE #2: 2.Tu, Thomas et al. "A Prospective, Single-Arm, Multicenter Trial of Catheter-Directed Mechanical Thrombectomy for Intermediate-Risk Acute Pulmonary Embolism: The FLARE Study.” JACC. Cardiovascular interventions vol. 12,9 (2019): 859-869. doi:10.1016/j.jcin.2018.12.022 DISCLOSURES: No relevant relationships by Mukul Bhattarai, source=Web Response No relevant relationships by radhika deshpande, source=Web Response no disclosure on file for Abdul Hafiz; No relevant relationships by Cameron Koester, source=Web Response No relevant relationships by Abhishek Kalidas Kulkarni, source=Web Response no disclosure on file for Mohsin Salih; No relevant relationships by Omar Siddiqui, source=Web Response