Tutorial
Uniportal VATS laterobasal segmentectomy (S9) of right lower lobe
Early-stage lung cancer is increasingly being managed by sublobar resection, which offers equivalent oncological results to lobectomy for lesions of less than 2 cm. However, isolated resection of the laterobasal segment (S9) is a difficult procedure and has rarely been reported via a uniportal video-assisted thoracoscopic (VATS) approach. The two key challenges are, first, the segmental arterial supply is deeply located in the lung parenchyma, making the dissection difficult, and second, the cuboidal shape of the lateral basilar segment hampers the identification of the intersegmental plane.
Laterobasal segmentectomy can be used to resect some non-solid tumors with ground-glass opacity suggesting early-stage non-small cell lung cancer (NSCLC) or some metastases . In this setting, sparing lung parenchyma by using a relatively less invasive resection is a technically complex procedure. Consequently, published reports on VATS S9 are rare . At our institution we have considerable experience with this procedure, and we believe it is both safe and effective. We describe our technique for uniportal VATS for a right S9 segmentectomy in this video tutorial.
1 - Patient presentation and preoperative planning (0:10)
A never-smoker 68-year-old woman being treated for a gastrointestinal stromal tumor (GIST) of the esophagus was referred to our thoracic surgery department with an incidental finding of a ground-glass opacity in the lateral segment of her right lower lobe. The PET-CT scan showed moderate uptake of fluorodeoxyglucose (FDG). After a multidisciplinary meeting, a lateral basal segmentectomy was proposed. The lesion was preoperatively identified with a hook wire.
General anesthesia is managed with a left double-lumen tube. The patient is positioned on her left side and the table is flexed to increase the distance between the ribs. A 4-cm incision is made in the 5th intercostal space, between the tip of the scapula and the breast, in the anterior axillary line. The wound is protected with a plastic soft-tissue retractor (Alexis, Retractor, Applied Medical, Rancho Santa Margarita, CA, USA).
The surgeon and the assistant are positioned on the anterior side of the patient with the scrub nurse standing at the back. A 10-mm 30º Endoeye thoracoscope (Olympus, Tokyo, Japan) is used in order to optimize the visualization of the pleural cavity and all mediastinal structures. A dissector (Scanlan International, St Paul, MN, USA), and a hook monopolar cautery are used for dissection and coagulation. All vessels are divided by endoscopic staplers (Echelon Flex, Ethicon, Somerville, NJ, USA).
2 - Segmental arterial dissection (1:41)
The pulmonary artery is approached in the middle portion of the major fissure. The basilar arterial trunk is dissected to be clearly identified. The lobar and segmental lymph nodes are removed, allowing better exposure of the segmental arteries and bronchi. The dissection is continued. The arterial branching pattern of the patient is as follows: A7 (medially), A8 (anteriorly) and A9+10 (laterally and posteriorly). Next, A9a is exposed, isolated, and cut with a curved-tip vascular endostapler.
3 - Segmental bronchial dissection (4:15)
Once the segmental artery is transected, the bronchial branch B9 is identified, medial to the A9 stump. The lateral segmental bronchus (B9) is isolated and divided. Care is taken to avoid injury to the posterior basal segmental artery, which lies dorsal to the segmental bronchus. At this point, an additional small A9b arterial branch is identified rising from A10. The additional A9b is encircled and divided.
4 - Division of the intersegmental plane (6:41)
The division of the intersegmental plane (ISP) is the most difficult step of the operation as this plane is tridimensional. The ISP can be identified by using a systemic injection of indocyanine green and a near-infrared imaging-system (Novadaq Inc, Ontario, Canada). This maneuver should be performed only after transection of the segmental arteries to delineate the demarcation line between the green-enhanced parenchyma (vascularized parenchyma) and normal parenchyma (devascularized parenchyma).
The ISP is then marked by electrocautery and divided by successive application of endoscopic staplers. During this maneuver, it is important to include the bronchovascular stumps in the specimen and to follow the division of the parenchyma in the direction of the segmental hilum. You can observe that the hook wire is useful to delineate the pulmonary lesion and plan sufficient surgical margins.
5 - Specimen retrieval and closure (8:49)
The specimen is retrieved in a bag and a systematic lymph node dissection is performed. Finally, an intercostal block with local anesthesia (bupivacaine 0.5%) is applied between the 2nd and 8th intercostal spaces. A 28 French chest tube is placed and the lung is re-expanded under direct vision.
6 - Postoperative outcome (9:29)
The overall surgical time was 90 minutes. The postoperative course was uneventful. The patient was discharged on the 3rd postoperative day. The histopathological analysis revealed an adenocarcinoma of 1.8 cm, pT1b pN0 R0. A follow-up CT-scan at 6 months did not reveal local or distant recurrence.
Laterobasal segmentectomy is an uncommon procedure, and it can only be safely performed using a uniportal approach if the broncho-vascular structures are properly identified. Consequently, few cases of isolated S9 segmentectomy have been reported . Reasons are as follows: The basilar arterial and bronchial trunks usually branch into A7+8 and A9+10, and B7+8 and B9+10 respectively. Due to these anatomical features, segment 9 is usually removed together with segment 10 in order to avoid adding further technical complexity.
The basilar segments’ vascular pattern can be highly variable. In this setting, it is imperative to perform a lengthwise dissection of the vessels in order to correctly identify the segmental branches and avoid errors. The cuboidal shape of the laterobasal segment makes the identification of the ISP difficult. In simple segmentectomies, where the stapling is linear, we usually identify the segmental plane after clamping the segmental bronchus and inflating the lung. However, when it comes to basal segments, where segmental tailoring is tridimensional, we found systemic injection of indocyanine green with a near-infrared imaging system to be more appropriate for identifying the ISP . As shown in the video, the indocyanine green clearly delineates S9.
Finally, to complete the ISP we strongly recommend careful control of the broncho-vascular stumps; we prefer them to follow the division of the parenchyma in the direction of the segmental hilum.
In summary, the VATS uniportal approach for S9 segmentectomies is feasible and can be a reasonable option for resection in some cases of early stage NSCLC and metastases.
- Handa Y, Tsutani Y, Mimae T, Tasaki T, Miyata Y, Okada M. Surgical Outcomes of Complex Versus Simple Segmentectomy for Stage I Non-Small Cell Lung Cancer. Ann Thorac Surg. 2019 Apr 1;107(4):1032–9.
PubMed Abstract | Publisher Full Text - Zhu Y, Pu Q, Liu C, Mei J, Liu L. Trans-Inferior-Pulmonary-Ligament Single-Direction Thoracoscopic RS9 Segmentectomy: Application of Stem-Branch Method for Tracking Anatomy. Ann Surg Oncol. 2020
PubMed Abstract | Publisher Full Text - Karenovics W, Gonzalez M. How to decrease technical obstacles to difficult video-assisted thoracoscopic surgery segmentectomy? J Thorac Dis. 2019 Jan 1;11(1):53–6.
PubMed Abstract | Publisher Full Text | Free Full Text - Bédat B, Abdelnour-Berchtold E, Krueger T, Perentes JY, Ris HB, Triponez F, et al. Clinical outcome and risk factors for complications after pulmonary segmentectomy by video-assisted thoracoscopic surgery: Results of an initial experience. J Thorac Dis. 2018 Aug;10(8):5023–9.
PubMed Abstract | Publisher Full Text | Free Full Text - Bédat B, Abdelnour-Berchtold E, Krueger T, Perentes JY, Zellweger M, Triponez F, et al. Impact of complex segmentectomies by video-assisted thoracic surgery on peri-operative outcomes. J Thorac Dis. 2019 Oct;11(10):4109–18.
PubMed Abstract | Publisher Full Text | Free Full Text
None declared.
Authors
Amaya Ojanguren, Céline Forster, and Michel Gonzalez
Authors' Affiliation
Service of Thoracic Surgery, Lausanne University Hospital, Lausanne, Switzerland
Corresponding Author
Michel Gonzalez
Service of Thoracic Surgery, Lausanne University Hospital, Lausanne, Switzerland
Phone: +41 79 5563820
Email: michel.gonzalez@chuv.ch
© The Author 2020. Published by MMCTS on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.
