Diaphragmatic Nerve Paralysis After Redo Aortic Valve Replacement That Improved Over Time and Led to Successful Ventilator Weaning: A Case Report

We report a 75-year-old female with a history of two heart operations: aortic valve replacement (St. Jude Medical^TM 21 mm) at the age of 44 years for severe rheumatic aortic stenosis and mitral valve replacement (Carbomedics^TM 29 mm) at the age of 51 years for rheumatic mitral regurgitation. Decades later, she presented with exertional dyspnea. Echocardiography revealed aortic stenosis with an effective orifice area of 0.79 cm². Coronary angiography showed #6 75% stenosis and a limited mechanical valve opening. After a thorough discussion, the patient agreed to undergo redo surgery. The surgery involved re-median sternotomy, left internal thoracic artery (LITA) harvesting, pannus removal, and replacement of the aortic valve with a 20 mm ATS advanced performance (AP) prosthesis (ATS Medical, Minneapolis, MN) in a supra-annular position. The LITA-left anterior descending (LAD) bypass was completed, and the patient was weaned from the cardiopulmonary bypass without complications. Postoperatively, the right phrenic nerve paralysis caused transient respiratory challenges requiring tracheotomy and prolonged ventilation. Rehabilitation improved diaphragmatic function and respiratory independence. At six months, the right phrenic nerve function had recovered, and the patient resumed walking independently with a cane. Two years postoperatively, the patient remained ambulatory and attended independent outpatient follow-ups. This report highlights the potential for gradual recovery from phrenic nerve paralysis following open heart surgery, emphasizing the importance of long-term multidisciplinary care.