Analysis of the variation pattern in right upper pulmonary veins and establishment of simplified vein models for anatomical segmentectomy

Abstract

ObjectiveThoracic surgeons must be erudite pulmonary vein variation when performing anatomical segmentectomy. We used three-dimensional CT (3DCT) to accumulate variations of the pulmonary veins of the right upper lobe (RUL) and created a simplified RUL vein model.MethodsWe reviewed anatomical variations of the RUL pulmonary veins of 338 patients using 3DCT images, and classified them by position related with bronchus.ResultsOf the “anterior” and “central” RUL veins, all could be classified into 4 types: 2 Anterior with Central types (Iab and Ib), 1 Anterior type, and 1 Central type. The Anterior with Central type was observed in 273 patients (81 %), and was further classified into two types according to the origin of the anterior vein. In the Iab type, the anterior vein originated from V1a to V1b (54 %) whereas, in the Ib type, the anterior vein originated from only V1b (26 %). The Central type, which had no anterior vein, was evident in 23 cases (7 %). These three types could be further divided into three subcategories by reference to the branching pattern of the central vein. The Anterior type, which had no central vein, was evident in 42 cases (12 %), and this type could be further categorized into two types, depending on the branching pattern of the anterior vein.ConclusionWe created a simplified RUL vein model to facilitate anatomical segmentectomy. Our models should find wide application, especially when thoracic surgery requiring anatomical RUL segmentectomy is planned.Electronic supplementary materialThe online version of this article (doi:10.1007/s11748-016-0686-4) contains supplementary material, which is available to authorized users.

Anatomical variations and pitfalls to know during thoracoscopic segmentectomies

“…It gives a large posterior branch for V 2 and small tributaries for V 3 . A small vein (V 2t ) draining S 2 frequently cross the posterior aspect of the ascending A 2 ( Figure 3) and must be severed before dissecting this artery (11).…”

3D-CT anatomy for VATS segmentectomy

“…The anatomical patterns are diverse, and the spatial configuration of the arteries, veins, and bronchi makes the entire picture even more difficult to understand. 3D-CTAB allows a 360-degree view of lung anatomy, and leads to rapid and intuitive recognition of individual anatomical patterns (22,26,27). By recognizing the branching pattern and spatial configuration of a patient's anatomy, 3D-CTAB allows the surgeon to plan anatomical segmentectomy preoperatively by deciding which intersegmental veins should be used as landmarks, which artery/vein/bronchi should be dissected, and in what order.…”

“…The most commonly reported type was the "anterior with central (Iab)" type, seen in 54% of cases. The remaining "anterior with central (Ib)" type, "anterior" type, and "central" type, were seen in 26%, 12%, and 7% of cases, respectively (22,26). Lastly, the bronchi are broadly classified into four patterns, based on whether they are bifurcated, trifurcated, quadrivial, or have a defect in the B 1 bronchi.…”

“…For patients with an "anterior with central" or "central" type pattern, V 2 c drains into the central vein; thus, the central vein should be denuded from the hilum to identify V 2 c. On the other hand, for patients with an "anterior" type pattern, V 2 c drains into the anterior vein; thus, the anterior vein should be denuded to identify V 2 c. The surgeon should especially recognize the branching pattern of these intersegmental veins and identify which vein should be used as a landmark and at what level the veins should be dissected. We previously proposed a simplified vein model of the RUL to aid surgeons in planning RUL segmentectomy (26).…”

“…Because the branching pattern of pulmonary veins is diverse (22,26), precise planning and intraoperative navigation of the pulmonary vessels that require denuding is essential.…”