A Case of Closure of the Foramen Ovale by Minimally Invasive Cardiac Surgery through Right Thoracotomy for the Treatment of the Platypnea-Orthodeoxia Syndrome Caused by a Patent Foramen Ovale

Abstract

The patient was a 78-year-old man who presented with dyspnea and decreased SpO₂ in the sitting and standing positions. Transthoracic echocardiography revealed a patent foramen ovale (PFO), and a microbubble test showed Grade 1 in the supine position and Grade 4 in the sitting position, suggesting an increase in shunt volume when seated. Chest CT revealed age-related kyphosis and right atrial compression by the ascending aorta. The patient was diagnosed with platypnea-orthodeoxia syndrome (POS) due to PFO, and a PFO closure was performed using minimally invasive cardiac surgery (MICS). The postoperative course was favorable, and the patient was discharged on the 20th postoperative day. Although percutaneous device closure is generally performed for PFO closure, MICS was useful in this case due to the anatomical unsuitability caused by an atrial septal aneurysm.