(190) Brachial Plexus Injury After Impella 5.5 Implantation

Introduction: Acute cardiogenic shock is a state of life-threatening low cardiac output leading to end-organ ischemia. The Impella 5.5, a microaxial left ventricular assist device, has seen increasing use in severe cardiogenic shock and can serve as a bridge to definitive therapy. The Impella provides forward flow while off-loading the ventricle; thereby reducing ventricular distention and myocardial injury. Due to its size, Impella 5.5 may require surgical vascular access when placed into the axillary artery which may result in nerve injury due to its proximity to the brachial plexus.

Description: A 66 year-old male with heart failure secondary to cardiac sarcoidosis was admitted due to congestive heart failure. Right-heart catheterization revealed elevated left-sided filling pressures, as well as reduced cardiac output and index: 3.21L/min and 1.48L/min/m², respectively. Despite medical management, cardiogenic shock continued to process with left ventricular distention. An Impella 5.5 was implanted for hemodynamic support as a bridge to transplant. POD 1 after Impella implant, the patient reported right upper extremity paresthesia and pain at the incision site. Despite multimodal analgesia, there was progressive numbness in the ulnar nerve distribution and profound weakness of the 4th and 5th digits. Heart transplantation occurred on Impella day 13 followed by removal of the device. POD 1 after transplant, the patient experienced improvement in right upper extremity symptoms. However, progressive ascending weakness affecting the right arm occurred POD 3. Imaging revealed edema adjacent to the axillary artery without hematoma. Electromyography revealed an acute right lower trunk brachial plexopathy. At discharge, the patient underwent intensive physical therapy at an inpatient rehabilitation facility. He continued to have right upper extremity weakness at 2 months after Impella removal and is unable to work.

Discussion: As an increasing number of mechanical circulatory support and cardiac devices are implanted, it is important to anticipate and recognize complications. Placement or removal of an Impella 5.5 may lead to brachial plexus injury due to its proximity to the axillary artery. If complications are not promptly recognized and treated, permanent nerve injury may occur.