Anatomy of the left subsuperior segment for segmentectomy

Purpose: The subsuperior segmental bronchi (B*) forms the subsuperior segment (S*) between the superior (S⁶) and basal segment (S⁷, S⁸, S⁹, S¹⁰) of the lung. However, the anatomical planes of S* remains undefined. The present study clarified the anatomical features of S*.

Methods: We reviewed the anatomical patterns of pulmonary vessels and the left lung bronchus in 539 patients using three-dimensional computed tomography. We report the anatomic structure in S*.

Results: A total of 537 patients were analyzed. B* was observed in 129 (24.0%) patients. The intersegmental vein between S⁶ and S* was complete in all cases. The absence of intersegmental veins of S* was observed in 77 (14.3%) patients, reaching 59.7% of B* cases. Twenty-two (4.1%) cases of B* diverged from the trunk of the basal bronchus, and about half of the B* branched to the dorsolateral (n = 77, 14.3%) or dorsal (n = 2, 0.37%) direction.

Conclusion: Our study revealed the branching patterns of B* and anatomical intersegmental veins of S*. Our results provide useful information regarding anatomical segmentectomy including or adjusting to the left S*.