Pulmonary embolism (PE) refers to an obstruction of the pulmonary arterial system and is the third leading cause of cardiovascular death. Patients can present with nonspecific findings; however, resulting pulmonary infarction, impaired gas exchange, and right ventricular failure can lead to rapid decompensation.
The Inari FlowTriever system allows proceduralists to perform a percutaneous, mechanical thrombectomy of this clot burden without thrombolytics. First, femoral vein access is obtained and a guide wire is advanced into the pulmonary vasculature with fluoroscopy through the clot. Then, a dilator is advanced over this wire to abut the clot. Suction is applied via a large bore syringe to extract the clot through the catheter. Finally, residual clot is captured with a second catheter containing self-expanding nitinol discs which “engage” the clot. These discs are pulled back into the trackable catheter dragging clot with them.
As a cardiac anesthesiologist, I perform monitored anesthesia care (MAC) for these patients with minimal sedation and lots of verbal reassurance. General anesthesia confers a very high likelihood of decompensation (positive pressure ventilation, decreased preload/inotropy, etc.), so I really want to avoid it. I’ll place a central line as many of these patients require vasopressors/inotropes, and an arterial line due to hemodynamic lability. Having blood available and a surgeon on standby is also paramount.
The 2018 multicenter FLARE trial looked at 106 patients with acute PE and echocardiographic evidence of RV strain (RV/LV ratio ≥ 0.9) who underwent the FlowTriever intervention. At 48 hours, there was a statistically significant reduction in the RV/LV ratio with no cases of intracranial hemorrhage, femoral vein bleeding, or device-related deaths.
Have you seen this system used before? Drop me a comment with your experience and thoughts!