Clinical application of three-dimensional reconstruction in anatomical analysis of the right anterior, lateral, and posterior basal segments (RS8, RS9, and RS10) for RS9 segmentectomy

Background: Anatomical RS9 segmentectomy is challenging due the intricate intersegmental planes (ISPs) and varied anatomical structures involved, with few studies having robustly assessed the three-dimensional (3D) reconstruction techniques for the anatomy and surgical procedures of the RS9 segment. This study aimed to analyze the application of 3D reconstruction for the vascular and bronchial branching patterns of the right anterior, lateral, and posterior basal segments (RS8, RS9, and RS10, respectively) for anatomical RS9 segmentectomy. Methods: From May 2020 to May 2022, 3D reconstructions of 354 patients were retrospectively analyzed in terms of vascular and bronchial branching patterns using Mimics 21.0 (Materialise). Based on the preoperative and intraoperative 3D reconstruction data, anatomical RS9 segmentectomy was performed in 27 patients, and the surgical outcomes were retrospectively analyzed. Results: The branching patterns of the right basal bronchi (B8, B9, and B10) were divided into the B8 and B9+10 type (74.6%); the B8+9 and B10 type (15.3%); and the B8, B9, and B10 type (10.2%). The branching patterns of the right basal arteries (A8, A9, and A10) were classified into a simple bifurcated type [the A8 and A9+10 type (62.4%) and the A8+9 and A10 type (13.0%)], split bifurcated type [the A8 and A8+9+10 type (18.4%) and the A8+9 and A9+10 type (3.7%)], and trifurcated type [the A8, A9, and A10 type (2.5%)]. The branching patterns of the right basal veins (V8, V9, and V10) were complex and were classified into simple bifurcated, split bifurcated, and trifurcated types and further divided into 10 subtypes. Of these types, the V8+9 and V10 type, the V8+9+10 and V10 type, and the V8+9 and V9+10 type were the most common, accounting for 29.4%, 25.4%, and 21.5% of the cases, respectively. Anatomical RS9 segmentectomy was successfully completed without conversion to thoracotomy in all 27 patients. Conclusions: 3D reconstruction is a practical tool for analyzing the bronchovascular branching patterns of RS8, RS9, and RS10. The application of 3D reconstruction is safe and feasible in anatomical RS9 segmentectomy.