OBJECTIVES The use of segmentectomy is expected to increase. However, understanding of the segmental bronchial branching is limited. Herein, we aimed to investigate bronchial branching pattern complexity and segmental volumetry of the right upper lung lobe to develop an accurate understanding of segmental anatomy and contribute to the advancement of safe and efficient lung segmentectomy. METHODS We evaluated chest computed tomography scans of 303 patients and categorized the branching of segmental bronchi (segment 1, apical; segment 2, posterior; and segment 3, anterior) into 4 major types (typical trifurcated, bifurcated non-defective, bifurcated defective and atypical trifurcated) and 11 subtypes. Segmental volumetry was performed to determine the predominant segment in each case (volume difference <5% was considered equal). Branching complexity was evaluated separately for volumetry-predominant and volumetry-non-predominant segments. RESULTS Trifurcated non-defective was the most frequent branching type (64.4%), followed by bifurcated non-defective (22.1%), bifurcated defective (8.6%) and trifurcated half-defective (4.0%). In terms of segmental volumetry, most cases had a one-segment-predominant distribution (71%) and only 5% of cases had equal distribution (segment 1 = segment 2 = segment 3). More than half of the cases had a segment 3-predominant distribution (52%). Branching complexity analysis revealed that the volumetry-non-predominant segment was associated with a higher risk of complex branching patterns compared with the volumetry-predominant segment (37% vs 19%, respectively; P < 0.005). CONCLUSIONS Volumetric assessment of the right upper lobe showed a heterogeneous segmental volume distribution. Care should be taken during lung segmentectomy of the volumetry-non-predominant segments because of the high risk associated with complex bronchial branching patterns. CLINICAL TRIAL REGISTRATION No. 4840.

中文翻译：

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右上叶的支气管分支模式和体积：对肺段切除计划的影响。

目标 肺段切除术的使用预计会增加。然而，对节段性支气管分支的了解是有限的。在此，我们的目的是研究右上肺叶的支气管分支模式复杂性和节段体积，以准确理解节段解剖结构，并有助于推进安全有效的肺段切除术。方法 我们评估了 303 名患者的胸部计算机断层扫描，并将节段性支气管的分支（第 1 段，顶端；第 2 段，后部；第 3 段，前部）分为 4 种主要类型（典型三分叉、分叉无缺陷、分叉缺陷和非典型三叉）和 11 种亚型。进行节段体积测定以确定每种情况下的主要节段（体积差异<5%被认为是相等的）。分别评估体积占主导地位和体积占非主导部分的分支复杂性。结果 三叉无缺陷是最常见的分支类型（64.4%），其次是二叉无缺陷（22.1%）、二叉缺陷（8.6%）和三叉半缺陷（4.0%）。就节段容积而言，大多数病例呈单节段主导分布（71%），只有 5% 的病例呈均等分布（节段 1 = 节段 2 = 节段 3）。超过一半的病例以节段 3 为主分布（52%）。分支复杂性分析表明，与体积占主导地位的片段相比，体积非占主导地位的片段与复杂分支模式的风险更高相关（分别为 37% 和 19%；P < 0.005）。结论 右上叶的体积评估显示出不均匀的节段体积分布。在对非主要肺段进行肺段切除术时应小心，因为与复杂的支气管分支模式相关的高风险。临床试验注册号 4840。