Intercostal pseudoaneurysm after median sternotomy treated with percutaneous thrombin injection

Intercostal artery pseudoaneurysm is an exceedingly rare complication seen after chest wall insult, either through trauma or operative procedures. We present a case of a 74-year-old man with mitral regurgitation and aortic stenosis who underwent aortic and mitral valve replacement via sternotomy. At the 1-month follow-up, a 1-cm pulsatile mass was noted adjacent to the left of the sternotomy in the sixth intercostal space. Concern for a pseudoaneurysm of the intercostal artery prompted evaluation with ultrasound, which demonstrated a pseudoaneurysm originating from an intercostal artery. This unusually located pseudoaneurysm was treated with ultrasound-guided thrombin injection with complete resolution.