Completion lobectomy following segmentectomy for malignant lung tumors: a multi-institutional study of surgical feasibility, oncologic outcomes, and diagnostic challenges (ESSG-02 study).

[BACKGROUND] Completion lobectomy (CL) is occasionally required after segmentectomy for malignant lung tumors, particularly in cases of local recurrence at the resection margins. However, evidence of its technical feasibility and long-term outcomes remains limited. This study aimed to evaluate the surgical feasibility and oncologic outcomes of CL following segmentectomy for malignant lung tumors in a multi-institutional cohort.

[METHODS] This multi-institutional retrospective study included 18 patients who underwent CL after segmentectomy for malignant lung tumors between 2000 and 2023. The surgical procedures, perioperative outcomes, and long-term survival were evaluated. An exploratory post-hoc analysis was also performed to compare clinical and radiological features of true local recurrence and granuloma.

[RESULTS] The most common indication for CL, based on preoperative clinical diagnosis, was local recurrence at the segmental resection margin (72.2%). Video-assisted thoracic surgery (VATS) was performed in 27.8% of patients, with no conversions to thoracotomy. Pulmonary artery (PA) injury occurred in 11.1% and postoperative complications in 27.8%, with prolonged air leak being the most common. Perioperative mortality was not observed. On final pathological diagnosis, 50.0% of patients had local recurrence, 27.8% had metachronous primary lung cancer, and 22.2% had granuloma. Among 13 patients clinically diagnosed with local recurrence preoperatively, 3 were ultimately diagnosed with granuloma. The 5-year overall survival (OS) rate after CL for local recurrence was 58.3%, with a median OS of 87.2 months. An exploratory analysis suggested that features such as interval tumor shrinkage and absence of vascular/bronchial involvement may aid in distinguishing recurrence from granuloma.

[CONCLUSIONS] CL after segmentectomy is a feasible and safe procedure when performed with careful planning and may provide encouraging long-term outcomes. Preoperative differentiation between local recurrence and granuloma remains a challenge and requires thorough imaging and tissue confirmation.