Robotic left S10 segmentectomy preserving an A9 branch missed on initial 3D-CT reconstruction: a lung base-flip approach

Abstract Accurate anatomical assessment is essential for precise pulmonary segmentectomy. We report a robotic left S10 segmentectomy in a 72-year-old woman in whom the initial three-dimensional computed tomography (3D-CT) reconstruction showed no pulmonary artery accompanying B9bii and focal irregularity of A10b. Re-evaluation of the contrast-enhanced CT images revealed a small A9bii arising from A10b that had not been depicted on the initial reconstruction. Manual correction of the 3D-CT images clarified the arterial anatomy and guided surgical planning. A lung base-flip approach provided a favorable caudal view of the deep A10b–A9bii bifurcation, enabling identification and preservation of A9bii. This case highlights the importance of recognizing anatomical discrepancies on reconstructed images, reassessing the CT images, and selecting an appropriate surgical approach to preserve anomalous pulmonary arterial branches.