Bedside VA-ECMO Cannulation for a Patient with CTEPH and RV Failure

Abstract

Introduction Acute pulmonary embolus (PE) in the setting of chronic thromboembolic pulmonary hypertension (CTEPH) with elevated PA pressures and right ventricular (RV) failure is a complex condition associated with increased mortality if left untreated. We demonstrate an alternative bedside veno-arterial extracorporeal membrane oxygenation (VA-ECMO) strategy used to facilitate stabilization and pre-operative optimization. Case Report A 29-year-old female with a history of previous PE (on Lovenox), RV dysfunction with elevated PA pressures, and IVC thrombus requiring VV-ECMO assisted suction embolectomy presented to an outside hospital with shortness of breath, hypoxia and CT demonstrating acute on chronic, bilateral PEs. A transthoracic echocardiogram (TTE) showed worsening RV function. She was normotensive, had a heart rate of 140, and was hypoxic so was placed on BiPAP. She was transferred to our facility for further management. On arrival, the patient was tachypneic and hypoxic. She was started on Epinephrine, Milrinone, and inhaled Epoprostenol but was persistently hypoxic with a rising lactic acid and worsening metabolic acidosis. With evidence of worsening RV failure, the patient was cannulated for VA-ECMO to facilitate optimization for advanced management. Prior to cannulation, bedside ultrasound revealed occlusive thrombus in both femoral and iliac veins. The venous drainage cannula was placed in the right internal jugular vein and the arterial return cannula was placed in the right common femoral artery, with antegrade reperfusion cannula. Bedside TTE was used to aide in cannula placement and cannula position was confirmed with x-ray.The patient was on VA-ECMO for 72 hours. During this time, her acidosis improved, Milrinone was weaned off, and she was diuresed. On ECMO day 3, she was taken to the OR for a pulmonary thromboendarterectomy and decannulated from VA-ECMO. The following day she was extubated and a TTE revealed improved right ventricular function. Summary Stabilization with VA-ECMO in patients with PE can be beneficial. This case illustrates the use of an alternative VA-ECMO cannulation strategy to optimize a patient with CTEPH. Of note, the cannulation occurred at the bedside with the use of ultrasound and without the need for intubation. Though this cannulation strategy is theoretically described in the literature, this case illustrates a concrete example of its use.