Right upper lobectomy for lung cancer associated with a displaced anomalous bronchus: two case reports.

Background: Bronchial bifurcation abnormalities are often discovered incidentally on chest computed tomography or bronchoscopy. As this condition is asymptomatic, it has little effect on the disease course of patients with lung cancer. However, this abnormality must be considered when performing lung resection.

Case presentation: Patient 1 was a 73-year-old man with suspected simultaneous triple lung cancers [cT1c (3) N0M0, Stage IA3] in the right and left upper lobes. He was initially scheduled to undergo right upper lobectomy and systematic nodal dissection. Chest computed tomography revealed a displaced B³ that arose from the right middle lobe bronchus. V¹⁺² was transected first, followed by the superior truncus of the pulmonary artery, and B¹⁺², respectively. After the branches of V³ were ligated, B³ was identified smoothly. Finally, the incomplete interlobar fissure between the upper and middle lobes was separated using an auto-stapler. No vascular abnormalities were observed. Patient 2 was a 62-year-old woman with suspected lung cancer (cT1cN0M0, Stage IA3) in the right upper lobe, and was scheduled to undergo right upper lobectomy and lobe-specific nodal dissection. Chest computed tomography revealed a right top pulmonary vein and a displaced B¹ that arose from the right main bronchus independently. Because V¹⁺³ was resected simultaneously during upper and middle lobe resection during robot-assisted thoracic surgery, the procedure was cool-converted to video-assisted thoracic surgery. An independently A¹ was observed, followed by A²_b and A³, which branched off as a common stem. A right top pulmonary vein was smoothly detected. Each blood vessel was transected using an auto-stapler. B²⁺³ was transected first using an auto-stapler, followed by B¹.

Conclusions: The displaced anomalous bronchus is often accompanied by pulmonary arterial or venous abnormalities and an incomplete interlobar fissure. A "hilum first, fissure last" technique is often useful. Preoperative evaluation and surgical planning are important.