Thoracoabdominal aortic replacement requires one-lung ventilation (OLV) and partial cardiopulmonary bypass (CPB). During right-sided OLV with femoral partial CPB, the coronary and supra-aortic branches are perfused by native cardiac output, making pulmonary oxygenation essential. Hypoxemia under these conditions may result in differential hypoxemia.

A 66-year-old woman underwent emergency thoracoabdominal aortic replacement for a ruptured Crawford type III thoracoabdominal aortic aneurysm. Refractory hypoxemia developed during right-sided OLV despite conventional interventions, including temporary resumption of two-lung ventilation, confirmation of double-lumen tube position, recruitment maneuvers, and ventilator adjustments. Because adequate oxygenation could not be maintained, the anesthesiologist proposed additional pulmonary artery (PA) perfusion as a rescue strategy. After multidisciplinary discussion with the surgeon and perfusionist, this approach was adopted. Partial CPB was established using triple cannulation consisting of right atrial drainage, femoral arterial perfusion, and PA perfusion. After PA perfusion was initiated, oxygenation improved, accompanied by clinically acceptable values of central venous oxygen saturation, near-infrared spectroscopy, and arterial blood gas analysis. The operation was completed successfully. The patient was extubated on postoperative day (POD) 3 without neurological complications, discharged from the intensive care unit on POD 6, and discharged from hospital on POD 16.

Additional PA perfusion during partial CPB may represent a feasible rescue strategy for selected patients who develop differential hypoxemia during OLV in thoracoabdominal aortic aneurysm surgery.