From the Guidelines
Proper Impella placement requires precise positioning across the aortic valve, with the inlet area in the left ventricle and the outlet area in the ascending aorta, to ensure effective circulatory support and minimize complications. When placing the Impella, it is crucial to position the device under fluoroscopic guidance, using a modified Seldinger technique via the femoral artery, and confirm its correct position with both pressure waveform analysis and echocardiography 1. The correct placement is indicated by the inlet sitting in the left ventricle to draw blood, while the outlet remains in the ascending aorta to deliver blood. Key considerations for placement include:
- Positioning too low may cause ventricular arrhythmias or damage to the mitral valve apparatus
- Positioning too high can result in device migration, aortic valve damage, or inadequate support After placement, the Impella should be secured to prevent migration, and regular position checks should be performed using echocardiography and device console waveforms. Proper anticoagulation with heparin is required to maintain an ACT of 160-180 seconds to prevent thrombus formation while minimizing bleeding risk, as noted in the context of mechanical circulatory support devices like the Impella 1. Careful monitoring of hemolysis markers is also essential during Impella support, given the potential for complications such as bleeding, thrombosis, and limb ischemia associated with the device 1.
From the Research
Impella Placement Guidelines
The proper placement of an Impella device in the aortic annulus is crucial for effective support of the left ventricle. However, the provided studies do not directly address the guidelines for Impella placement.
Aortic Valve Considerations
- The aortic valve plays a critical role in the functioning of left ventricular assist devices (LVADs) 2, 3.
- Aortic insufficiency (AI) is a common issue in patients with LVADs, and it can progress or develop de novo after implantation 3.
- Surgical methods, such as central oversewing of the aortic valve or aortic valve replacement, can be used to correct AI in patients supported with CF-LVADs 3.
Device Placement and Function
- Proper alignment of the device inflow cannula is important for long-term success, as seen in a case study of a patient supported with a HeartMate II continuous-flow left ventricular assist device 4.
- The flow rate of the device can also impact its longevity, although the exact relationship between flow rate and device longevity is unknown and requires further investigation 4.
Limitations
There are no direct research papers to assist in answering the question of normal Impella placement on the aortic annulus. The provided studies focus on the interactions between continuous-flow left ventricular assist devices and the aortic valve, rather than Impella placement specifically.