LAUSR

Various complications can cause hypoxemia after pulmonary resection for lung cancer, but intracardiac shunt that becomes symptomatic and causes severe hypoxemia postoperatively is very rare. We report a case that presented platypnea-orthodeoxia syndrome (POS) due to right-to-left shunt via patent foramen ovale (PFO). A 71-year-old man with a lung cancer in the left upper lobe was referred to our hospital. Left upper lobectomy was performed. Dyspnea developed postoperatively, which was worsened by sitting or standing and relieved in a recumbent position. Contrast transesophageal echocardiogram (TEE) and right intracardiac catheterization revealed a right-to-left shunt via PFO. Open-heart closure of PFO was performed and the patient was free from POS. Postoperative intracardiac shunt via PFO can cause severe hypoxemia after lung resection. POS suggests the possibility of intracardiac shunt and careful observation is needed.