Anatomical Analysis of the Left Upper Lobe of Lung on Three-Dimensional Images with Focusing the Branching Pattern of the Subsegmental Veins

Abstract

Background: Although a clear understanding of the anatomical characteristics of the pulmonary veins (PVs) is essential for the successful performance of segmentectomy and is important to avoid intraoperative pulmonary vessels injury, there is no report showing the relations between the branching patterns of PVs and pulmonary arteries (PAs). Moreover, internationally accepted symbols for describing the PVs remain unavailable. For anatomically assessing the branches and courses of the subsegmental veins in the left upper lobe (LUL), the diverse branching patterns of blood vessels and bronchi should be investigated. Methods: The branching patterns and intersegmental courses of PVs were assessed by performing three-dimensional image analysis of the bronchi, and PAs and PVs in the LUL in 103 patients who were scheduled to receive segmentectomy in LUL from January 2008 through August 2012. Results: Branching types of the bronchus and pulmonary vessels failed to be independent each other. Combinations of anterior extension type of bronchi with the inter-lobar type (IL-type) of arterial branching pattern were often observed, but those with the mediastinal type (M-type) were rarely observed. The combinations of apical vein dominant type with the IL-type of arteries, and intermediate and central vein type with the M-type were often observed. LUL was adjoined by various subsegments, and the intersegmental pulmonary veins showed diverse patterns. Conclusions: This study found the relationship among PA, PV, and bronchus patterns, and in the subsegment where the branching patters were fixed in 103 cases. This study discovered PVs that was difficult to be named by the conventional naming systems because of the diversity of the locations in the subsegment.