Uniportal thoracoscopic lateral and posterior basal (S9+10) segmentectomy

Among uncommon pulmonary segmentectomies, the lateral and posterior basal (S9+10) segmentectomy is one of the most challenging because it requires exposure and recognition of common basal pulmonary vein branches located deep in lung parenchyma. In order to achieve an optimal thoracoscopic S9+10 via a uniportal approach the surgeon must first select the most suitable uniportal method, because the angulation of surgical instruments is limited in this minimally invasive approach and this makes it especially difficult to perform. 

In this video tutorial, we demonstrate our technique for a uniportal thoracoscopic S9+10 segmentectomy; we discuss our successful results, and explain the nuances of performing the procedure.

Our group has reported previously on the effectiveness and technical details of several different types of uncommon pulmonary segmentectomies.  Uncommon segmentectomies are considered technically more difficult to perform than common segmentectomies [1,2] and, among them, the lateral and posterior basal (S9+10) segmentectomy is one of the most challenging because it requires exposure and recognition of common basal pulmonary vein branches, which are located deep in lung parenchyma. 

In order to achieve an effective thoracoscopic S9+10 segmentectomy via a multiportal approach, we have, in the past, used an “intersegmental tunneling method” and we have achieved  successful results in 5 patients [2]. However, this technique would be difficult to use via a uniportal approach because it requires bidirectional dissection, whereas a uniportal approach must rely on unidirectional dissection due to limited angulation of the instruments [3]. In addition, the maneuver of encircling and dividing the lateral and posterior basal bronchus (B9+10) at the fissure can be a struggle because of the narrow space and limited angle of a uniportal approach. 

In this video tutorial, we will demonstrate our surgical technique for a uniportal S9+10 segmentectomy.

An 81-year-old man with no relevant past medical history consulted our hospital because chest computed tomography (CT) revealed an approximately 25-mm part-solid nodular shadow (7-mm solid part) in the lateral basal (S9) segment. Primary lung cancer was strongly suspected, without any evidence of intrathoracic lymph node or distant metastasis.Uniportal thoracoscopic S9+10 segmentectomy as an intentionally limited resection was planned with the operative candidate of cT1aN0M0, stageⅠA1 lung cancer. 

The operation was performed under general anesthesia using one-lung ventilation with the patient in the lateral decubitus position. We placed a 3.5-cm access incision on the 5th intercostal space at the anterior axillary line. A 5-mm thoracoscope with a 30° angle and all other surgical instruments were inserted through the single incision.

Outcome
The postoperative course of the patient was uneventful. We removed the chest drainage tube on the 1st postoperative day and the patient was discharged on the 3rd postoperative day.

Discussion
We successfully achieved pulmonary S9+10 segmentectomy of the right lower lobe via a uniportal approach. In this procedure, the key step, or trick, is to expose and divide the B9+10 not at the fissure but at the hilum, which is a different technique from the “intersegmental tunneling” method our group previously described [2]. 

We still consider the intersegmental tunneling method to be very useful for achieving this type of segmentectomy because tunneling enables the surgeon to easily recognize the common basal pulmonary vein branches, which are located deep in the lung parenchyma, once the division of the intersegmental plane between S6 and S9+10 is complete. However, this method might be unsuitable for a uniportal approach because it requires “bidirectional” dissection, which can be very difficult to achieve uniportally. To accomplish it, the surgeon must dissect V6b+c at the hilum, and it is difficult to get a good surgical view of the posterior side via a uniportal approach. Insufficient dissection of V6b+c at the hilum makes intersegmental tunneling technically difficult to perform. In addition, it is also technically difficult to encircle and divide the B9+10 at the fissure because of the narrow space and the limited angle of movement available via a uniportal approach. 

To overcome these technical difficulties, we recommend dividing B9+10 at the hilum after division of the dominant vein to S9+10 during uniportal thoracoscopic S9+10 segmentectomy. Using this method, we can easily expose the B9+10 and perform smooth stapling because there is enough space for surgical manipulations. Instead of using intersegmental tunneling to find the  common basal pulmonary vein branches in the lung parenchyma , we can use a preoperative 3D-CTA [4]. However, this imaging must be evaluated carefully to ensure an accurate reading.   

In 2015, Kikkawa et al. reported a similar technique to ours for thoracoscopic S9+10 segmentectomy but their approach was multiportal [5] and the dominant pulmonary artery to S9+10 was also exposed and divided at hilum, which we did not do. We divided the artery at the interlobar fissure in this patient because it was almost complete; Kikkawa’s method could be useful for patients having a fused fissure. 

In conclusion, while thoracoscopic uniportal S9+10 segmentectomy is technically challenging, our method is safe and feasible and we have demonstrated here that it is a valid surgical approach.

1. Igai H, Kamiyoshihara M, Yoshikawa R, Ohsawa F, Yazawa T. The safety and feasibility of thoracoscopic uncommon pulmonary segmentectomy. J Thorac Dis. 2019 Jul;11(7):2788–94.
   PubMed Abstract | Publisher Full Text | Free Full Text
2. Igai H, Kamiyoshihara M, Kawatani N, Ibe T. Thoracoscopic lateral and posterior basal (S9+10) segmentectomy using intersegmental tunnelling. Eur J Cardiothorac Surg. 2017 Apr 1;51(4):790–1.
   PubMed Abstract | EJCTS Full Text
3. Igai H, Matsuura N, Kamiyoshihara M. Uniportal thoracoscopic upper division segmentectomy of left upper lobe using a unidirectional anterior approach. Multimed Man Cardiothorac Surg. 2020 May 12; 2020.
   PubMed Abstract | Publisher Full Text
4. Oizumi H, Kanauchi N, Kato H, Tndoh M, Suzuki J, Fukaya K, et al. Anatomic thoracoscopic pulmonary segmentectomy under 3-dimensional multidetector computed tomography simulation : A report of 52 consecutive cases. J Thorac Cardiovasc Surg. 2011;141:678–82.
   PubMed Abstract | Publisher Full Text
5. Kikkawa T, Kanzaki M, Isaka T, Onuki T. Complete thoracoscopic S9 or S10 segmentectomy through a pulmonary ligament approach. J Thorac Cardiovasc Surg. 2015;149:937–9.
   PubMed Abstract | Publisher Full Text

None declared.

Authors
Hitoshi Igai, MD, PhD, Natsumi Matsuura, MD, PhD, and Mitsuhiro Kamiyoshihara, MD, PhD  

Authors Affiliations
Department of General Thoracic Surgery, Japanese Red Cross Maebashi Hospital

Corresponding Author
Hitoshi Igai, MD, PhD, 
Department of General Thoracic Surgery,
Japanese Red Cross Maebashi Hospital
371-0811 Asakura-cho, Maebashi,
Gunma 371-0811, Japan

Phone: +81-27-265-3333  
Fax: +81-27-225-5250
Email:hitoshiigai@gmail.com