Surgical outcomes of complex segmentectomy for clinical stage IA non-small cell lung cancer adjacent to the intersegmental plane between S6 and the basal segments

We investigated the clinical efficacy of complex segmentectomy for non-small cell lung cancer (NSCLC) adjacent to the intersegmental plane between S6 and the basal segments. Between 2009 and 2023, 135 patients with clinical stage IA NSCLC adjacent to the intersegmental plane in the lower lobe were retrospectively evaluated. We identified the intersegmental plane using three-dimensional (3D) image analysis systems and measured the distance (X) from the intersegmental plane to the tumor’s caudal side. Tumor location was classified into four: group A: located in S6, 10 ≤ X < 20 mm; group B: located in S6, 0 < X < 10 mm; group C: on the plane (X = 0); and group D: located in the basal segments. Clinicopathological characteristics, perioperative outcomes, and recurrence patterns were compared between S6 ( n = 123) and complex ( n = 12) segmentectomy. Tumor distribution was 43 (32%) in group A, 35 (26%) in group B, 15 (11%) in group C, and 42 (31%) in group D. Complex segmentectomy was performed more frequently in group D (58% vs. 28%, p = 0.03). Pure-solid tumors were more frequent in the complex segmentectomy group (42% vs. 20%, p = 0.07). Operative time was longer in complex segmentectomy than that in S6 segmentectomy (142 vs. 132 min, p = 0.07); however, postoperative complications were similar between the two procedures (grade ≥ 3: 8% vs. 11%). Local recurrence occurred in three patients, which was exclusive to S6 segmentectomy. Complex segmentectomy may be considered in selected cases to secure adequate surgical margins based on preoperative three-dimensional evaluation.