Robot-assisted thoracoscopic right upper lobectomy with displaced B3 and absence of minor fissure: a case report.

Introduction: B³ downward-shifting is a rare bronchial anomaly characterized by abnormal pulmonary arteries associated with downward displacement of B³ and complete fusion between the right upper and middle lobes.

Case presentation: We report a case of robot-assisted thoracoscopic right upper lobectomy in a patient with lung cancer with B³ downward-shifting. An 81-year-old male was diagnosed with non-small cell lung cancer in S3 of the right upper lung. Preoperative three-dimensional computed tomography angiography revealed a B³ bronchus derived from the middle lobe bronchus and an anterior segmental pulmonary artery variation. Robot-assisted thoracoscopic surgery right upper lobectomy with ND2a-1 was performed via four-port incisions and an assist incision. No interlobar fissure was observed between the right upper and middle lobes. After dissecting B¹⁺², the displaced B³ root was dissected. The displaced A³a was difficult to dissect because of an extremely severe complete fissure. Therefore, we dissected the bronchus preceding from the cranial side. To confirm a minor fissure, indocyanine green was administered intravenously, and the interlobar boundary was identified as the line separating the dark and green lung parenchyma. The boundary was divided using mechanical staples. No surgical complications occurred.

Conclusions: Using three-dimensional reconstruction imaging and systemic indocyanine green administration, we successfully performed a right upper lobectomy through robot-assisted thoracic surgery.