Recognition of subsuperior segmental vein for thoracoscopic subsuperior segmentectomy.

Central MessageSubsuperior segmental vein anatomy is important for single or combined subsuperior segment segmentectomy. Subsuperior segmental vein anatomy is important for single or combined subsuperior segment segmentectomy. The subsuperior segment (S∗), observed independent subsegment between S6 and basal segments of the lower lobe, has a prevalence of 32.04% and frequencies of 20.4% and 24.0% in the right and left lungs, respectively.1Nagashima T. Shimizu K. Ohtaki Y. Obayashi K. Nakazawa S. Mogi A. et al.Analysis of variation in bronchovascular pattern of the right middle and lower lobes of the lung using three-dimensional CT angiography and bronchography.Gen Thorac Cardiovasc Surg. 2017; 65: 343-349Crossref PubMed Scopus (43) Google Scholar, 2Maki R. Miyajima M. Ogura K. Tada M. Takahashi Y. Adachi H. et al.Anatomy of the left subsuperior segment for segmentectomy.Surg Today. 2022; 52: 1054-10622Crossref PubMed Scopus (4) Google Scholar, 3Zhou D. Gao Y. Wang H. Xin H. Zhao J. Zhu X. et al.Prevalence and anatomical characteristics of subsuperior segment in lung lower lobe.J Thorac Cardiovasc Surg. 2022; ([Epub ahead of print])Google Scholar, 4Shimizu K. Mogi A. Yajima T. Nagashima T. Ohtaki Y. Obayashi K. et al.Thoracoscopic subsuperior segment segmentectomy.Ann Thorac Surg. 2017; 104: 407-410Abstract Full Text Full Text PDF PubMed Scopus (11) Google Scholar Therefore, it is expected that many thoracic surgeons will recognize S∗ and perform single or combined S∗ segmentectomy in the future. However, few reports regarding surgical techniques and anatomic features focus on S∗,4Shimizu K. Mogi A. Yajima T. Nagashima T. Ohtaki Y. Obayashi K. et al.Thoracoscopic subsuperior segment segmentectomy.Ann Thorac Surg. 2017; 104: 407-410Abstract Full Text Full Text PDF PubMed Scopus (11) Google Scholar,5Liu G. Hu H. Dong P. Zhang S. Mao Z. Modified left subsuperior segmentectomy via 2-cm uniportal video-assisted thoracoscopic surgery.Surg Today. 2021; 51: 172-175Crossref PubMed Scopus (5) Google Scholar with no studies on subsuperior segmental vein (V∗) anatomy in S∗ segmentectomy. We share our technical experience with anatomic single or combined S∗ segmentectomy. Per the institution, Institutional Review Board approval was not required. Individual consent for the publication of study data was obtained. All patients provided consent for any research activity. Patient demographics and treatment approaches are outlined in Table 1. We identified V∗ in all patients from computed tomography (CT) and 3-dimensional (3D) CT; however, patients 1 and 3 had V∗ as intersegmental veins, but not patient 2 (Figures E1, A-C, E2, A-C, and 1, A-D).Table 1Demographics and treatment approaches in 3 patients undergoing anatomic single or combined S∗ segmentectomyVariablesPatient 1Patient 2Patient 3SexFemaleMaleFemaleAge at operation, y667178Medical history about tumorBreast and lung cancer--Preoperative diagnosisPrimary lung cancerPrimary lung cancerPrimary lung cancerTumor locationPeriphery of S∗ of RLLPeriphery of S6 of RLLPeriphery of S∗ of LLLTotal tumor (solid part) size, mm13 (13)20 (20)25 (8)Clinical TNMT1bN0M0T1bN0M0T1aN0M0Clinical stageIA2IA2IA1Origin of B∗from B10from B9+10from B9+10Intersegmental veins between S∗ and basal segmentsV∗Nothing2 V∗Surgical approachVATSVATSVATSPerformed procedureS∗ segmentectomyS6+S∗ segmentectomyS6c+S∗ segmentectomySubcarinal lymph node dissectionYesYesYesOperative time, min219248241Blood loss, mL5505Pathological TNM-T1cN0M0T1aN0M0Pathological stage-IA3IA1Postoperative histopathologyBreast cancerInvasive adenocarcinomaInvasive adenocarcinomaSurgical margin, mm212023S∗, Subsuperior segment; RLL, right lower lobe; LLL, left lower lobe; TNM, tumor-node-metastasis; B∗, subsuperior segmental bronchus; V∗, subsuperior segmental vein; VATS, video-assisted thoracoscopic surgery. Open table in a new tab S∗, Subsuperior segment; RLL, right lower lobe; LLL, left lower lobe; TNM, tumor-node-metastasis; B∗, subsuperior segmental bronchus; V∗, subsuperior segmental vein; VATS, video-assisted thoracoscopic surgery. Right S∗ segmentectomy was performed. A9+10 was identified between S6 and S8 (Figure E1, D). V6, V∗, and basal veins were identified in the dorsal direction. A10 was dissected dorsally, and B10, V6b, and V6c were identified. The intersegmental plane between S6 and S∗ was divided using endoscopic staplers along V6b and V6c. After ligation and division of V∗, B10+∗ was dissected caudally, and the subsuperior segmental bronchus (B∗) was divided with an endoscopic stapler. The subsuperior segmental artery (A∗) was ligated and divided. The intersegmental plane between S∗ and S10 was divided using endoscopic staplers (Figure E1, E). Right S6+S∗ segmentectomy was performed to obtain sufficient surgical margins. A6 was identified. After ligation and division of A6 and A∗, B6 was divided using an endoscopic stapler (Figure E2, D). After ligation and division of V6, B∗ was divided using an endoscopic stapler. The central side of S6+S∗ was divided with endoscopic staplers along the caudal side of V∗. On the peripheral side, S6+S∗ was divided using endoscopic staplers to obtain sufficient surgical margins. Left S6c+S∗ segmentectomy was performed to obtain sufficient surgical margins. V6 was dissected peripherally. After division of V6c, B6c and A6c behind V6b were dissected and divided. A6, A8, and A9+10 were identified in the interlobar (Figure 1, E). A∗ originating from A8 was divided, and then B∗ was identified. Selective segmental jet ventilation was performed through B∗ to create the inflation-deflation line (Video 1). After division of B∗, V6b was identified between A6 and A9+10. S6c+S∗ was divided from S6a+S6b along V6b, and 2 V∗ were ligated and divided from V8. S6c+S∗ was divided from basal segments along 2 V∗ and the inflation-deflation line (Video 1). S∗ is not rare.1Nagashima T. Shimizu K. Ohtaki Y. Obayashi K. Nakazawa S. Mogi A. et al.Analysis of variation in bronchovascular pattern of the right middle and lower lobes of the lung using three-dimensional CT angiography and bronchography.Gen Thorac Cardiovasc Surg. 2017; 65: 343-349Crossref PubMed Scopus (43) Google Scholar, 2Maki R. Miyajima M. Ogura K. Tada M. Takahashi Y. Adachi H. et al.Anatomy of the left subsuperior segment for segmentectomy.Surg Today. 2022; 52: 1054-10622Crossref PubMed Scopus (4) Google Scholar, 3Zhou D. Gao Y. Wang H. Xin H. Zhao J. Zhu X. et al.Prevalence and anatomical characteristics of subsuperior segment in lung lower lobe.J Thorac Cardiovasc Surg. 2022; ([Epub ahead of print])Google Scholar Therefore, anatomic knowledge of S∗ bronchovascular patterns is important for thoracic surgeons, especially when performing single or combined S∗ segmentectomy safely. Maki and colleagues2Maki R. Miyajima M. Ogura K. Tada M. Takahashi Y. Adachi H. et al.Anatomy of the left subsuperior segment for segmentectomy.Surg Today. 2022; 52: 1054-10622Crossref PubMed Scopus (4) Google Scholar reported that the intersegmental veins between S6 and S∗ are V6b or V6c in the left lung. However, Nagashima and colleagues1Nagashima T. Shimizu K. Ohtaki Y. Obayashi K. Nakazawa S. Mogi A. et al.Analysis of variation in bronchovascular pattern of the right middle and lower lobes of the lung using three-dimensional CT angiography and bronchography.Gen Thorac Cardiovasc Surg. 2017; 65: 343-349Crossref PubMed Scopus (43) Google Scholar reported that V∗ branching pattern is complex and could not be classified. Additionally, there are no reports of a venous pattern separating S∗ from basal segments of the right lung. Therefore, the problem lies between basal segments and S∗. As expected, in all cases, intersegmental veins between S6 and S∗ were V6b or V6c. In case 1, V∗ was perfused into V10 between S∗ and S10. Therefore, it was easy to divide the intersegmental plane between S∗ and S10. However, surgical margins between V9a and the tumor were close; therefore, we divided the intersegmental plane with surgical margins, rather than along V9a. When B∗ branches from B9+10, the intersegmental vein between S∗ and S9+S10 is absent in 73.3% of cases. In case 2, B∗ branched from B9+10, and the intersegmental vein between S∗ and S9+S10 was not observed, but V∗, which could indicate surgical margins from the tumor, was observed. Therefore, we divided between S∗ and S9+S10 along this vein on the central side and between S∗ and S9+S10, prioritizing surgical margins from the tumor on the peripheral side. In case 3, 2 V∗ formed an intersegmental plane between S∗ and other basal segments. In the left lung, among B8 and B9+10 type cases, 2 V∗ forming an intersegmental plane between S∗ and other basal segments are rare (0.19%)2Maki R. Miyajima M. Ogura K. Tada M. Takahashi Y. Adachi H. et al.Anatomy of the left subsuperior segment for segmentectomy.Surg Today. 2022; 52: 1054-10622Crossref PubMed Scopus (4) Google Scholar; however, S∗ segmentectomy was easy to divide by identification of 2 intersegmental veins in case 3. Our 3 cases demonstrate preoperative recognition of intersegmental veins and V∗ between basal segments and S∗ is important for single or combined S∗ segmentectomy.