Axillary IABP Prolapse into the Ascending Aorta: A Rare Anatomic Challenge
Harsh Doshi, M.D., Thomas Jefferson University Hospital, Philadelphia, PA
Harsh Doshi, M.D.1, Gregary Marhekfa, M.D. FACC1, David Lee Fischman, M.D., FSCAI1, Michael P. Savage, M.D., MSCAI1, Nicholas J. Ruggiero II, M.D., FSCAI2, Baskaran Sundaram, M.D.1, Indranee Rajapreyar, M.D.1 and Alec Vishnevsky, M.D.1, (1)Thomas Jefferson University Hospital, Philadelphia, PA, (2)Thomas Jefferson University Hospital, Flourtown, PA
Title:
Recurrent Axillary IABP Prolapse
Introduction
Insertion of an intra-aortic balloon pump (IABP) through the axillary artery has been increasingly utilized in cardiogenic shock patients as a bridge to a left ventricular assist device or cardiac transplant. This approach liberates patients from prolonged bed rest associated with femoral IABP placement and encourages ambulation to prevent deconditioning. With this alternative access, new complications arise. We describe a rare case of axillary IABP placement complicated by recurrent device prolapse into the ascending aorta.
Clinical Case
57-year old female with ischemic cardiomyopathy (EF 15%) presented with ventricular tachycardia storm and cardiogenic shock (SCAI class C). She underwent percutaneous 8 french 50 cc left axillary IABP insertion as bridge to heart/kidney transplant. 13 days after placement, the fiberoptic sensors on IABP failed. The waveform on the IABP console showed inadequate augmentation. Chest x-ray (CXR) demonstrated proximal and distal metallic markers in stable position. However in the catheterization lab under fluoroscopy, the IABP was seen to be partially folded and prolapsed into the ascending aorta. The IABP was exchanged for another axillary IABP and positioned so that the proximal marker was 1-2 cm beyond the origin of the left subclavian artery. The patient subsequently had two more instances of IABP prolapse. The first following a mechanical fall and a second without antecedent events. In each case, CXR demonstrated the proximal marker to be positioned near the aortic knob, but the distal marker was visualized high in the descending thoracic aorta. No IABP console alarms were triggered during these episodes. A 3D CT suggested that her recurrent prolapse into the ascending aorta was due an anatomical challenge. The left subclavian artery inserted at the distal aspect of the ascending aorta, and her subclavian-aortic angle was acute (<50 degrees) likely causing the IABP to migrate into the ascending aorta with each pulsation. Ultimately, the patient was transitioned to a femoral IABP and the axillary arteriotomy was closed with a Perclose.
Discussion
Our case highlights an insidious complication of IABPs that can occur when the device is inserted through the axillary artery. In certain patients, the device can prolapse into the ascending aorta. We hypothesize this occurs when the subclavian artery inserts proximally in the aortic arch, and when the subclavian-aortic angle is < 50 degrees. This is one of several patients at our institution with similar anatomy with recurrent IABP prolapse. This complication is challenging to diagnose since the prolapse can occur without console alarms. Careful attention should be paid to subtle changes in proximal and distal marker position on daily CXR. When the diagnosis is in question, chest CT or fluoroscopy can confirm device prolapse into the ascending aorta. When prolapse occurs, we recommend urgent exchange of the IABP due to the risk of damage to the aortic arch vessels or device prolapse into the left ventricle. CT chest angiography prior to placement of axillary IABP may identify patients at risk of this complication through assessment of the origin of the left subclavian artery and the subclavian-aortic angle.