Right video-assisted thoracoscopic surgery subsuperior segmentectomy after right upper lobectomy: a case report

Introduction

Background

The subsuperior segment (S*) is an independent segment occasionally observed between the superior segment (S6) and the posterior basal segment (S10) of the pulmonary lobe. Previous studies have reported a 20.4% frequency of this segment in right pulmonary lobe cases (1,2). This anatomical variation has significant implications for thoracic surgery, particularly in procedures involving minimally invasive segmentectomy.

Rationale and knowledge gap

Despite the frequency of the S* segment, performing an S* segmentectomy using a minimally invasive approach remains challenging. Accurate preoperative recognition of anatomical structures, including the pulmonary artery, vein, and bronchus, using three-dimensional computed tomography (3D-CT) is crucial. Additionally, recent clinical trials for small-sized peripheral non-small cell lung cancer surgery have indicated an increase in the number of segmentectomies (3,4). This trend will likely lead to more opportunities to perform segmentectomy after ipsilateral pulmonary anatomical resection, a technique that presents additional challenges due to its complexity.

Objective

The objective of this study is to report the first case of a right S* segmentectomy following ipsilateral anatomical pulmonary resection. By documenting this case, we aim to provide insights into the surgical techniques and anatomical considerations necessary for successfully performing this complex procedure. We present this case in accordance with the CARE reporting checklist (available at https://asj.amegroups.com/article/view/10.21037/asj-24-18/rc).

Case presentation

All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Helsinki Declaration (as revised in 2013). Written informed consent was obtained from the patient for the publication of this case report, the accompanying images and video. A copy of the written consent is available for review by the editorial office of this journal.

A 71-year-old male patient, who had no symptoms, reported a history of right upper lobectomy 2 years ago for primary lung cancer (papillary adenocarcinoma, stage IA2) and chemoradiation therapy (concurrent cisplatin and 70 Gy/35 Fr dose of radiotherapy) four years ago for mesopharyngeal cancer (squamous cell carcinoma, stage I). Additionally, he had no medication history, and had chronic obstructive pulmonary disease, and his preoperative forced expiratory volume in 1 s was 59.1%. His routine CT scan after initial surgery revealed a right pulmonary solid nodule (1 cm) enlargement was detected in the S* segment (Figure 1). Hilar and mediastinal lymph nodes demonstrated no enlargement. Positron emission tomography-CT revealed a maximum standardized uptake value of 3.3, consistent with a lung nodule. He was suspected to have a metastatic lung cancer from either lung or mesopharyngeal cancer. Therefore, we planned video-assisted thoracoscopic surgery (VATS) right S* segmentectomy as a compromised limited surgery because the subsequent treatment based on which cancer had metastasized to the lung. Lung volume calculation was performed before surgery using Synapse Vincent software (Fujifilm Corp., Tokyo, Japan), which was used for lung resection analysis. We calculated right lower lobe volume and right S* volume on 3D-CT before right upper lobectomy and before S* segmentectomy following right upper lobectomy. The results showed an increased S* segment volume by 20% (from 184 to 222 mL) and right lower lobe volume by 40% (from 1,635 to 2,282 mL). Therefore, we determined through preoperative simulation that S* segmentectomy alone would provide sufficient margin (1 cm) because the tumor diameter was 1 cm.

Figure 1 Preoperative CT image. Preoperative CT image showing a gradually increased solid nodule (1 cm) in the subsuperior segment (S*) (yellow arrow). CT, computed tomography.

Multi-port VATS approach was selected, and four ports were placed as follows: fourth anterior, fifth anterior, sixth posterior, and seventh mid-intercostal space (ICS) (Figure 2). Video 1 showed right VATS S* segmentectomy after right upper lobectomy. We exposed V6 to the periphery from the right lower lobe’s posterior view. We subsequently palpated the lesion and marked the lung parenchyma near the nodule. After, we exposed the pulmonary artery (PA) from the untouched pulmonary fissure between the right-middle and lower lobe during the initial surgery. During the initial surgery, only A6a was dissected because A6 was bifurcated, A6a and A6b + c (Figure 3A,3B). Therefore, we exposed A6b + c. We then dissected basal PA to the periphery and exposed V6c from the interlobar view. Afterward, we tunneled and divided the intersegmental plane between S6 and S*. We subsequently divided A*, B*, and V* in this order. We divided the remaining intersegmental planes under the guidance of indocyanine green after denuding on the B* stump peripheral side. The operative time was 168 min, and the blood loss was minimal. The postoperative course was uneventful. Chest tube was removed on postoperative day 2 after confirming that there was no air leak and that the drainage volume was less than 300 mL. He was discharged on postoperative day 8 for his convenience although it is possible to leave the hospital on postoperative day 3. The pathological examination confirmed complete lesion resection, and the nodule was metachronous primary pulmonary adenocarcinoma (papillary adenocarcinoma, pT1aN0M0, stage IA1). The resection margin of 1.5 cm was secured. He reported no recurrence 1 year postoperatively.

Figure 2 Schema of the surgical position. The schema demonstrating the position and port placement during surgery. The surgeon stood on the patient’s ventral side while the first assistant stood on the dorsal side. The second assistant stood caudal to the surgeon as a scopist. ICS, intercostal space.

Figure 3 Preoperative 3D-CT following right upper lobectomy. (A) 3D-CT from the right side. A6 was bifurcated into A6a and A6b + c. A* and B* branched from between A6/B6 and A10/B10. (B) 3D-CT from dorsal side. 3D-CT, three-dimensional computed tomography.

Discussion

Key findings

S* exhibits a small volume and is an infrequently observed subsegment, but its independent subsuperior segmental bronchus and artery are distinct from those of S6 and S10 (2). Patients with lung cancer not typically underwent S* segmentectomy because efficient safety margins cannot be secured. However, S* segmentectomy is an appropriate surgical procedure for lung lesions, including our case, and metastasized from other malignancies and nonmalignant diseases, such as pseudotumors, because S* is found in areas unresectable by wedge resection.

Strengths and limitations

The advantages of our multi-port VATS are that it can be operated from various angles, and it is also excellent educationally because the surgeon and assistant can work together. Another advantage is that tumor localization can be confirmed by palpation. Current robotic surgery does not have a tactile function. Virtual assisted lung mapping and radiofrequency identification lung marking system are also available for preoperative identification of tumor location (5,6). Although these methods are very useful, not all institutions have them, and our institution does not have them either. In such cases, the ability to palpate in multiport VATS is a great advantage for solid nodule.

The disadvantage of multiport VATS is that it has a larger number of wounds than a uniportal VATS. However, a uniportal VATS was not considered because the S* segmentectomy mainly involved a dorsal approach, and it was post-right upper lobectomy where the dissection of the PA sheath was anticipated to be particularly important. Although it does not matter what the approach is as long as the quality of the surgery is not compromised, we decided that the multiport VATS approach was appropriate for this procedure at our institution.

Comparison with similar researches

The CALGB 140503 ad hoc analysis reported no difference in results between wedge resection and segmentectomy (7). However, in our case, the lesion was palpable but somewhat central, so the segmentectomy was chosen. A wedge resection of a lesion that is somewhat central or central makes it uncertain whether a margin can be secured. In addition, this study design is indicated for small peripheral lesions and should not be applied to somewhat central lesions such as this case. In such a case, we believe it is better to perform a segmentectomy to secure surgical margin.

Ipsilateral repeated anatomical pulmonary resection following anatomical pulmonary resection is difficult because the first operation results in a high degree of hilar structure adhesion. Previous studies reported high mortality (0–4%) and high postoperative complications (10–55%) for ipsilateral repeated anatomical pulmonary resection following anatomical pulmonary resection (8-10).

Explanations of findings

A6 dissection after right upper lobectomy is frequently difficult. This is because the branching of A6 is usually identified and exposed partially during right upper lobectomy. However, this patient exhibited an A6 type with two branches (A6a and A6b + c), and A6b + c was not determined and exposed at the initial surgery. Therefore, we identified and exposed A6b + c via the pulmonary fissure between the right-middle and lower lobe, which was left untouched during the initial surgery. Hence, we completed this surgery thoracoscopically. Additionally, we would have converted to thoracotomy, secured the main PA, and then performed this surgery if the A6b + c was difficult to expose, or if the A6 was a single branch. A previous study revealed that completion lobectomy was more difficult approximately 5 weeks following a segmentectomy operation, due to the presence of more severe adhesions around the pulmonary hilum, whereas another study reported that adhesion at the pulmonary hilum did not markedly differ based on the interval between the initial and second surgeries (9,11). A high degree of adhesion must be assumed if a pulmonary hilum or vascular dissection is required near the initial surgery despite not completing lobectomy. Therefore, confirming the details of the first surgery and preoperatively simulating the second surgery are extremely important in cases of repeat surgery.

The results of recent clinical trials (3,4) indicated that the segmentectomy for small-sized (<2 cm) peripheral non-small cell lung cancer will increase in the future; thus, becoming proficient in pulmonary segmentectomy techniques, is important. Additionally, the increase in the number of limited surgeries may increase the experience of repeat lung surgery for metachronous and metastatic lung cancers. Therefore, treatment strategies need to be considered for such cases in the future.

Conclusions

This case was successfully treated without postoperative complications due to proper preoperative simulation. VATS complex segmentectomy can be safely performed even after ipsilateral anatomical pulmonary resection. However, ensuring the procedure’s safety is crucial, and thoracic surgeons must be prepared to convert to thoracotomy in emergencies, such as bleeding.

Acknowledgments

We thank Moli G, PhD from Enago (https://www.enago.jp) for English editing a draft of this manuscript.

Funding: None.

Footnote

Reporting Checklist: The authors have completed the CARE reporting checklist. Available at https://asj.amegroups.com/article/view/10.21037/asj-24-18/rc

Peer Review File: Available at https://asj.amegroups.com/article/view/10.21037/asj-24-18/prf

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://asj.amegroups.com/article/view/10.21037/asj-24-18/coif). T.Y. serves as an unpaid editorial board member of AME Surgical Journal from August 2023 to July 2025. The other authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy of integrity of any part of the work are appropriately investigated and resolved. All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Helsinki Declaration (as revised in 2013). Written informed consent was obtained from the patient for the publication of this case report, the accompanying images and video. A copy of the written consent is available for review by the editorial office of this journal.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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