Thoracoscopic segmentectomy for “black lung”: a case report

Introduction

Background

Segmentectomy is a standard procedure for the treatment of small-sized lung cancer (1), resulting in a favorable overall survival. However, a major concern regarding segmentectomy is locoregional recurrence. Therefore, to reduce the risk of recurrence, identification of the intersegmental plane is considered essential. To identify the intersegmental plane, several techniques have been reported, including the inflation-deflation arterial ligation, and indocyanine green (ICG) method (2-8).

Rationale and knowledge gap

Although current techniques work effectively in an intact or normal lung, they are not effective in the lungs of patients with severe emphysema or anthracosis, known as “black lung” (8). Therefore, it is possible that segmentectomy would be needed in these cases.

Objective

Herein, we report a case of a S8–9 segmentectomy performed using the intersegmental veins as anatomical landmarks in a patient with severe anthracosis. We present this case in accordance with the CARE reporting checklist (available at https://vats.amegroups.com/article/view/10.21037/vats-23-75/rc).

Case presentation

Clinical presentation

A 75-year-old man, who was a heavy smoker (smoking index of 1,600), was referred to Yamagata University Hospital due to a diagnosis of lung cancer. He had previously worked as a rice farmer. Computed tomography (CT) showed solid lung nodules in the right S3 (21 mm) and left S8 (17 mm) segments. The right lung nodule was diagnosed as an adenocarcinoma by CT-guided biopsy; however, a diagnosis could not be achieved for the left nodule, which was subsequently suspected to be lung cancer. In the preoperative examination for distant metastases, no metastases were found in the brain magnetic resonance imaging (MRI), and the positron emission tomography (PET) CT scan showed no fluorodeoxyglucose (FDG) accumulation in lymph nodes suspected of metastasis. The values for respiratory function were a vital capacity (VC) value of 3,080 mL (%VC: 94.5%) and a forced expiratory volume in the first second (FEV1.0) of 2,100 mL (FEV1.0%: 71.9%). We decided to perform surgery for the tumor in the right lung and planned a two-stage surgery for the left lung nodule.

Thoracoscopic right upper lobectomy and ND2a-2 lymph node dissection were performed for the tumor on the right side. Intraoperative findings revealed a visceral pleural surface with anthracosis, although this was within the expected range for a smoker. The final pathology result was adenocarcinoma (pT2aN0M0–1B).

Three months after the first surgery, a thoracoscopic left S8–9 segmentectomy was scheduled (Video 1). Aside for the interlobar pleural surface, the entire pleura appeared totally black due to severe anthracosis (Figure 1A). Following pulmonary hilum manipulation, we attempted to identify the intersegmental plane by ICG fluorescence and inflation-deflation line; however, it was impossible to identify due to the severe anthracosis (Figure 1). The intersegmental plane was finally identified via dissection of intersegmental veins as anatomical landmarks.

Figure 1 The appearance of the visceral pleura before (A) and after (B) ICG fluorescence and the inflation-deflation line from the interlobar side (C) and lateral side (D). ICG, indocyanine green.

We performed a thoracoscopic S8–9 segmentectomy based on the inter-and intra-segmental veins identified by conventional and three-dimensional (3D) CT imaging (Figure 2).

Figure 2 Schematic of the postoperative state. (A) Photograph of surgical field. (B) Schema of surgical field.

The postoperative course was uneventful. After surgery, air leakage was not observed, and the chest tube was removed on postoperative day 1. The patient was discharged 4 days after surgery. Although the patient was in stage 1B, they opted not to undergo chemotherapy with tegafur uracil (UFT). For follow-up, examinations were conducted every 6 months for the first 2 years, including CT scans and blood tests that included tumor markers. Afterward, the examinations were performed annually, consisting of CT scans and blood tests with tumor markers. Five years have passed since the surgery and the patient is now surviving without recurrence.

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). The institutional review board of Yamagata University Faculty of Medicine approved this study (No. 2023-S-67) on October 19, 2023. Written informed consent was obtained from the patient for the publication of this case report, and accompanying images and video. A copy of the written consent is available for review by the editorial office of this journal.

Discussion

Achieving a sufficient surgical margin is essential when performing a segmentectomy. Therefore, the method used to identify the intersegmental plane is often a point of discussion, and several techniques have been advocated.

Okada et al. (2) reported the inflation-deflation technique. This technique is useful to identify the intersegmental plane. To perform this method in a simplified thoracoscopic procedure, we previously reported a slip-knot technique for bronchial ligation (3). In addition, to further shorten the time required to visualize the inflation deflation line, we have reported a selected segmental insufflation technique (4). However, in some cases, the intersegmental plane is not clearly visualized by the presence of Kohn’s pores or Lambert canals; in such cases, ICG fluorescence can increase the accuracy of identifying the intersegmental plane (8).

ICG fluorescence does not require the need to inflate the lung; thus, surgeons are able to perform surgery without disruption of the surgical field. Iizuka et al. (7) reported that 98.6% of segments and/or subsegments can be detected via the ICG method. They revealed that a smoking index >800 and low attenuation aria >1% on CT are predictive factors of ICG visualization. Therefore, depending on the lung condition and comorbidities, it is possible that ICG method could be ineffective in locating the intersegmental plane.

The arterial ligation method to determine the intersegmental plane has also been investigated (5,6). However, this technique cannot be applied to all cases and is dependent on the anatomy or condition of the patient. In one study, the intersegmental plane could only be detected in 2 of 140 cases owing to serious anthracosis (5). Given the results of these reports, the surgical technique for segmentectomy in patients with a smoking history or anthracosis should be recognized as challenging, including both the intraoperative procedure and postoperative complications.

Segmentectomy based on a dissection along the intersegmental veins is a conventional procedure. Dissection of the intersegmental veins as anatomical landmarks can result in the intersegmental plane being missed; however, 3D CT can help to define the true anatomy and orientation. When utilizing an intersegmental vein procedure, accurate interpretation of 3D CT imaging is mandatory. We have previously reported the importance of identifying intersegmental veins through 3D CT simulations and the necessity of dissecting these veins to their periphery (9).

Furthermore, even in relatively complicated cases of basal segmentectomies, the intersegmental vein procedure is powerful technique; recently, we showed a case of a thoracoscopic S9 segmentectomy using the intersegmental vein procedure. The merit of this procedure is that it can avoid extra parenchymal splitting and can be used for segmentectomy in incomplete fissure cases (10).

The present case had planned to undergo a thoracoscopic S8–9 segmentectomy; however, the lung had severe anthracosis. Although we could not use inflation-deflation, arterial ligation, or ICG method, the intersegmental vein procedure effectively provided visualization of the intersegmental plane. This case highlights the importance of going back to basics and performing surgery based on the anatomy of the intersegmental veins.

Conclusions

Thoracoscopic segmentectomy was successfully performed in patient who had a lung with severe anthracosis, otherwise known as “black lung”. Despite being a conventional method, dissection of the intersegmental veins is a steady and powerful procedure that is useful in troublesome cases.

Acknowledgments

Funding: None.

Footnote

Reporting Checklist: The authors have completed the CARE reporting checklist. Available at https://vats.amegroups.com/article/view/10.21037/vats-23-75/rc

Peer Review File: Available at https://vats.amegroups.com/article/view/10.21037/vats-23-75/prf

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://vats.amegroups.com/article/view/10.21037/vats-23-75/coif). The 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 or 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). The Institutional Review Board of Yamagata University Faculty of Medicine approved this study (No. 2023-S-67) on October 19, 2023. Written informed consent was obtained from the patient for the publication of this case report, and 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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