Impella 5.5® with SmartAssist®: Echocardiography for Real-time Positioning

Echocardiography is the only way to visualize in real-time the relationship of the Impella 5.5 with SmartAssist to structures within the left ventricle. This video explains when to obtain an echo and how to use echocardiography to determine Impella® catheter positioning.

Obtaining an echo of the Impella 5.5 with SmartAssist is important to:

• Determine if the catheter is in a stable position
• Assess left and right ventricular function
• Evaluate whether Impella is interfering with valve function

Proper position not only promotes patient safety, but allows the heart to rest and provides adequate hemodynamic support to optimize the likelihood of myocardial recovery.

Abiomed recommends that an echo be obtained:

• Prior to the Impella 5.5 with SmartAssist being inserted in the OR
• As part of the ICU check-in process
• Any time catheter migration is suspected or there are unresolved suction events or blood compatibility concerns
• Periodically to assess for myocardial recovery, especially prior to weaning the pump

The best view for evaluating the position of the Impella 5.5 using transthoracic echo (TTE) is the parasternal long axis view. With this view you can:

• Confirm that the inlet area is in the midventricular space free of mitral valve structures
• Confirm that the catheter is directed toward the apex
• Get an accurate measurement from the mid-inlet to the aortic valve annulus
• Ensure that the outlet is in the aorta above the aortic valve

Because one 2-D view won’t provide all the information you need to ensure proper positioning within the ventricle, it is important to obtain multiple views on every patient to verify the relationship of the Impella catheter with intracardiac structures.

When the Impella 5.5 with SmartAssist is properly positioned, the distance from the aortic valve annulus to the mid-inlet should be approximately 5 cm with the bend of the cannula seated at the aortic valve. Color Doppler can assist in determining where the outlet is sitting in relationship to the aortic valve. It is important that you don’t see outflow from the outlet too close to the aortic valve or in the left ventricular outflow tract as this could lead to positioning alarms, suction events, or blood compatibility concerns.

The Impella 5.5 with SmartAssist is usually implanted in the OR with the assistance of fluoroscopy and transesophageal echo (TEE). The mid-esophageal long axis view is the optimal TEE view for visualizing the catheter. With this view you can confirm positioning in the midventricular space and ensure the inlet is directed toward the apex and is free of mitral subvalvular structures. This TEE view enables accurate measuring from the aortic valve annulus to the mid-inlet and confirms the outlet is above the aortic valve. Again, it is important to obtain multiple TEE views of the Impella catheter to verify its relationship with intracardiac structures.