Atypical type D extended sleeve resection after neoadjuvant chemoimmunotherapy in a 69-year-old man with locally advanced lung cancer and a tracheobronchial branching anomaly: a case report.

Background: Neoadjuvant chemoimmunotherapy has improved resectability in locally advanced non-small cell lung cancer (NSCLC); however, its impact on complex bronchioplastic procedures remains controversial. In particular, the feasibility of extended sleeve resection (ESL) in patients with rare tracheobronchial branching anomaly after immunochemotherapy has rarely been reported. Herein, we present a rare case of an atypical type D extended sleeve resection performed to avoid pneumonectomy in a patient with a rare bronchial branching anomaly. Case Description: A 69-year-old man with a heavy smoking history presented with hemoptysis. Computed tomography (CT) imaging revealed a 7.9 cm right hilar tumor with invasion of the intermediate bronchial trunk and suspected involvement of the upper lobe bronchus, accompanied by a tracheobronchial branching anomaly (B1). He was diagnosed with lung squamous cell carcinoma; the clinical stage was cT4N2aM0 (stage IIIB). Given the high programmed death-ligand 1 (PD-L1) expression [tumor proportion score (TPS) 90%] and the potential to avoid pneumonectomy if tumor reduction was achieved, neoadjuvant chemoimmunotherapy (cisplatin, gemcitabine, and nivolumab) was administered. A partial response was obtained, and the tumor regressed to a level amenable to bronchioplastic resection. Atypical type D ESL (right middle and lower lobe resection and anastomosis of the right main bronchus to B2+3) was successfully performed. Intraoperative frozen section confirmed negative margins of the bronchus, and an air leak test demonstrated airtight anastomosis. Despite caliber mismatch, reconstruction was achieved using a telescoping technique and by aligning the axes. The postoperative course was uneventful except for adrenal insufficiency as an immune-related adverse event (irAE), which immediately improved with steroid therapy. Histopathology showed ypT2aN1M0 with partial response, and no recurrence was observed at 10 months. Conclusions: This case suggests that neoadjuvant chemoimmunotherapy combined with bronchioplasty may enable curative, lung-preserving resection while avoiding pneumonectomy. In atypical extended sleeve reconstruction with marked caliber mismatch, tension reduction, preservation of bronchial blood supply, and careful adjustment of bronchial caliber and axial alignment are essential. Favorable anastomotic healing suggests the feasibility of bronchioplasty after chemoimmunotherapy, although further experience is needed.