Feasibility assessment in uniportal video-assisted thoracoscopic anatomic pulmonary resection

Introduction

Anatomical lung resection with uniportal video-assisted thoracoscopic surgery (UVATS) was first reported in 2011 (1) and has been increasing globally. It is considered less painful (2,3) and cosmetically better than multi-portal video-assisted surgery (MVATS) because it involves a single incision. Department of General Thoracic Surgery, Osaka University Graduate School of Medicine started lobectomy using the UVATS approach in April 2019 and segmentectomy in April 2020. The indications of UVATS include primary lung cancer up to clinical stage 1, metastatic lung cancer, and benign disease. The aim of this study is to verify the perioperative safety and surgical outcomes, as well as treatment outcomes for patients with primary lung cancer, and to compare them with MVATS 5 years after its introduction. We present this article in accordance with the STROBE reporting checklist (available at https://vats.amegroups.com/article/view/10.21037/vats-24-25/rc).

Methods

Patients

This study enrolled patients who underwent scheduled uniportal video-assisted lobectomy or segmentectomy from April 2019 to December 2023 as the U group. For comparison, patients who underwent lobectomy or segmentectomy by MVATS from April 2018 to March 2019, the year before introducing UVATS, were included in the M group.

The endpoints include perioperative safety and prognosis. Further, this study included patients who were converted to MVATS by additional port or thoracotomy. The conversion rate, complications, and other perioperative outcomes were retrospectively investigated. A propensity score matching (PSM) analysis was performed to investigate prognostic factors, such as survival and relapse, for patients with primary lung cancer.

The study was conducted in accordance with the Declaration of Helsinki (as revised in 2013). The study was approved by the Ethics Review Board for Clinical Studies at Osaka University (No. 10026-3), and individual consent was waived because of its retrospective nature.

Surgical procedure and postoperative course

Department of General Thoracic Surgery, Osaka University Graduate School of Medicine defined UVATS through a 4-cm single incision according to the report by Gonzalez-Rivas et al. (1). In principle, a window is placed on the anterior-middle axillary line between the fifth intercostal space, but the sixth or fourth intercostal space was used based on the case. The surgeon is positioned on the patient’s ventral side and the assistant on the dorsal side. The field of view is in a look-up setting. The thoracoscope has a 10 or 5 mm diameter and 30 degrees. LAP PROTECTOR Mini-elliptical (Hakko Co., Ltd., Nagano, Japan) or Alexis wound retractor XS (Applied Medical Co., Ltd., Rancho Santa Margarita, CA, USA) provided wound protection. Forceps dedicated to uniportal surgery, such as long single-shaft lung grasping forceps, are very useful, and curved devices of aspirators, energy devices, and retraction forceps are similar.

MVATS is performed with two windows and one port. One window for the operator is set on the anterior-mid axillary line of the fourth intercostal space and another one for the assistant is on the posterior axillary line of the seventh intercostal space. Further, a 10-mm port for scope is set on the midaxillary line of the seventh intercostal space. UVATS is a reduced-port surgery that eliminates the caudal and dorsal wounds from MVATS style. Several general thoracic surgeons composed of authors, with nearly identical surgical teams in Department of General Thoracic Surgery, Osaka University Graduate School of Medicine, performed these operations.

Lymph node dissection is performed in UVATS as well as in MVATS, but since the number of dissected nodes does not reflect the pathological stage of lung cancer, we only compared regions of dissection.

Postoperative treatment is standardized using a clinical path for all patients. The criteria for drainage tube removal are absolutely no air leakage and no chylothorax. The definition of postoperative complications was based on the Clavien-Dindo classification. The patient can be discharged after confirming that there are no complications.

Statistical analysis

Data are expressed as the mean ± standard deviation. Comparisons between two groups were made using an unpaired t-test, a Mann-Whitney U-test, with a Chi-squared test used for categorical variables. The propensity scores were estimated using a logistic model including the following variables: sex, age, smoking, clinical stage. Survival rate was calculated using Kaplan-Meier method from the date of surgery until the time of death for any causes [overall survival (OS)], and recurrence [relapse-free survival (RFS)], and last visit (censored OS and RFS). Probability values of <0.05 were to be considered significant. All analyses were performed using the JM17.0.2 statistical software package (SAS Institute Inc., Cary, NC, USA).

Results

This study enrolled 121 patients who underwent scheduled lobectomy or segmentectomy by UVATS as the U group. For comparison, 73 patients who underwent lobectomy or segmentectomy by MVATS were included in the M group.

Perioperative outcomes

Table 1 shows the patient’s background and similar other backgrounds despite the slightly greater number of women in the U group. Two patients in clinical stage (c-stage) 2A whose tumors were over 4 cm received UVATS lobectomy at the patient’s request. Table 2 presents the perioperative outcomes. The U group demonstrated less operative time and shorter postoperative hospital stay. Eight patients were converted to open thoracotomy. The rate of cases in which no port was added or conversion to thoracotomy in UVATS and MVATS were 6.6% and 6.8%, respectively, with no significant difference. Each of the U and M groups had one reactive conversion to thoracotomy due to hemorrhage from a pulmonary artery. Other cases were strategical conversion due to adhesions, poor collapse, or one-lung ventilation difficulties. The U group had 5 (4.1%) patients with additional ports because of poor collapse in 3 and stapling difficulty during vessel dissection in 2. All patients underwent the procedure without blood transfusion. Perioperative complications in the U group were in 20 (16.5%), and severe complications defined as grade ≥3 by Clavien-Dindo classification were in 8 (6.6%), with seven re-operations, including four by air leakage, one by pulmonary torsion, one by bleeding from the incision, and one by lung congestion. No significant difference was observed between the two groups. No deaths were reported within 90 days postoperatively.

The incidence of perioperative complications was compared between 55 cases within 2.5 years after introduction until October 2021 (early period) and 66 cases after November 2021 (latter period). Postoperative complications occurred similarly in 12 and 8 cases in early and latter periods, respectively (P=0.22). However, severe complications were significantly more prevalent in the early than in the latter period in 7 and 1 cases, respectively (P=0.02). The number of cases requiring re-operation was significantly decreased in the second term, including 6 and 1 in the early and latter periods, respectively (P=0.044).

Primary lung cancer outcomes

PSM was performed in 173 primary lung cancer cases, and 63 patients were matched in each of the two groups. Tables 3,4 show post-match comparisons. Complications and length of hospital stay were not significantly different compared to the M group despite the significantly shorter operation time in the U group. Table 5 presents the results of clinicopathological factors and prognosis in all patients. There were 4 cases of N factor upstaging due to lymph node metastasis, three of which were in the M group and one in the U group. Recurrence occurred in two cases in the U group. One case demonstrated a distant metastatic recurrence with pathological stage 1A3 after right upper lobectomy with ND2a-2 for adenocarcinoma, and another case was diagnosed with small cell carcinoma with pathological stage 1A2 postoperatively, which relapsed with multiple lymph node metastasis. The 5-year OS was 98.5% and 98.9% (P=0.90) (Figure 1A) and the 5-year RFS was 90.1% and 97.9% in the M and U groups (P=0.043) (Figure 1B), respectively, but with no significant difference in OS (P=0.42) (Figure 1C) or RFS (P=0.36) (Figure 1D) when compared after PSM.

Figure 1 Kaplan-Meier survival curves accordingly to (A) overall survival, (B) relapse-free survival in all primary lung cancer cases, (C) overall survival and (D) relapse-free survival after propensity matching. MVATS, multiportal video-assisted thoracoscopic surgery; UVATS, uniportal video-assisted thoracoscopic surgery.

Discussion

UVATS has the potential as one of the best minimally invasive surgery for patients to guarantee the quality of pulmonary resection and its efficacy as a malignant tumor treatment. The quality of pulmonary resection is assessed in terms of perioperative safety, including operation time, hospital stay, blood loss, postoperative complications, etc., whereas the effectiveness of the surgical procedure as a malignancy treatment is evaluated in terms of recurrence and survival rates. More than 10 years have already passed since it was first reported (1), and the number of facilities introducing it is increasing, with several reports.

Perioperative safety

Many reports have revealed that UVATS is not inferior to MVATS in safety, including less drainage duration, less hospital stay, less intraoperative blood loss, and less pain compared to MVATS (3,4). Meta-analyses have revealed similar or better results (5-7). Operating time and hospital stay were shorter in UVATS, but a significant difference was observed only in the operative time in lung cancer cases. Safety was not affected by the approach. However, severe complications and re-operations were more frequent in the early period since UVATS introduction. We experienced re-operations especially due to air leakage with tears in the staple line shortly after starting UPTS. The stapler can only be inserted from one direction, making it one of the most difficult points to deal with from MVATS. The position of the stapler cannot be changed significantly; thus, it needs to be deployed in a direction that enables safe structure dissection, achieved by dissecting the structure to the periphery and firmly separating it from the surrounding tissue. These are tips in UVATS, limiting the difficulty in inserting the stapler. Of course, strategical conversion before accidents is crucial. Adding ports or converting to thoracotomy should not be hesitated during difficulty in UVATS. Operating with an experienced surgeon at the introduction will be better, as well as learning the tips unique to UVATS, for safety and rapid learning. According to the report about learning curve, it was reported that 60 experiences needed for the initial phase, and 140 cases were needed to reach the proficient phase (8). If the surgeons who have mastered MVATS, it would be possible to shorten the learning curve in our experience. The transition from MVATS to UVATS will be easier by reducing the number of ports individually in terms of education.

UVATS indication

Our indications include early-stage lung cancer, metastatic lung cancer, and benign disease. The benign disease may exhibit severe adhesion, but a report indicated aspergiroma (9). Non-tuberculous mycobacteriosis was a good indication of UVATS in our cases, particularly those without severe adhesion. The speed of recovery enables a quick transition to the next chemotherapy or other treatment in the case of metastatic lung cancer. UVATS may be an acceptable procedure for diseases other than primary lung cancer.

Feasibility as a lung cancer treatment

Lung cancer treatment was comparable in perioperative results and long-term prognosis compared to MVATS by PSM analysis. Operation time was shorter in UVATS, this can be associated with the fact that UVATS surgeons at Department of General Thoracic Surgery, Osaka University Graduate School of Medicine became skilled in MVATS before shifting to UVATS.

Lymph node dissection is comparable to that of conventional MVATS (10), with a similar number of lymph nodes dissected (11,12). UVATS demonstrated good postoperative outcomes without compromising safety or oncologic prognosis (13). Early lung cancer exhibited a good long-term prognosis (14). Some reports described the prognosis as superior (12) or comparable (12,14-16). Favorable results are reported not only for lobectomy but also for segmentectomy (7). Our study, which included both lobectomy and segmentectomy mainly in patients with early-stage lung cancer, revealed no significant differences in OS and RFS. The observation period remains short and insufficient in the U group, but the prognosis can be expected not to be inferior to that of MVATS, at least in early lung cancer up to c-stage 1. The indication of UVATS for primary lung cancer in Department of General Thoracic Surgery, Osaka University Graduate School of Medicine includes patients with up to c-stage 1, whereas MVATS or open thoracotomy is for N1, and open thoracotomy for N2 or advanced cancer requiring concurrent resection because UVATS for advanced cancer surgery needs to be selected cautiously. A consensus report from the Uniportal VATS Interest Group of the European Society of Thoracic Surgeon in 2019 states that tumor size of <5 cm (T1–T2b) and N0–N1 lesions are considered indications for lobectomy with UVATS (16). Conversely, more advanced operations, such as bronchoplasty and angioplasty, are possible with UVATS (17-19). UVATS for advanced cancer with plasty has been feasible, but it should be performed by well-trained thoracic surgeons. The perioperative outcome is safe even with UVATS for advanced cancer (20), and early recovery enables an early introduction to the next adjuvant therapy (21). Further, we have experienced cases of upstaged treated with adjuvant therapy and patients with metastatic lung cancer who required chemotherapy, all of whom improved to a general condition that enables treatment 1 month postoperatively, indicating that UVATS provides an early transition to the next treatment stage. Reports on the long-term prognosis of UVATS for advanced cancer remain limited; thus, the indication should be carefully considered while awaiting future analysis.

Limitations

However, many retrospective reports revealed the possibility of effectiveness in UVATS, satisfactory comparison of long-term results between UVATS and MVATS is difficult due to the lack of large-scale prospective studies, and this is an issue to be addressed in the future. Similarly, this is a retrospective study which may have a bias in patient selection. Patients with fewer pulmonary comorbidities and younger, relatively healthy patients were selected after the introduction of UVATS especially in the about the first six months. No statistical difference in overall patient background was observed, so the results were considered valid. The indication is limited to early-stage cancer; thus, UVATS validity for advanced cancer cannot be proven, and it is at least a feasible surgical approach for c-stage 1 lung cancer. However, since UVATS was performed by surgeons skilled in MVATS, the possibility that bias by the surgeon may have resulted in the surgical outcome cannot be ruled out. Therefore, the outcome needs to be continuously evaluated over a period of observation. UVATS is considered a good approach because it can be safely performed for benign disease and metastatic lung tumors, but the number of cases is small, and accumulating more cases to build evidence will be required.

Conclusions

The perioperative outcome and prognosis for early-stage primary lung cancer in UVATS were favorable compared to MVATS. The indication for advanced cancer needs to be carefully considered, but UVATS is considered useful for early-stage lung cancer up to c-stage 1, metastatic lung cancer, and lung resection of benign disease. However, complications in the early period from introduction should be noted.

Acknowledgments

None.

Footnote

Reporting Checklist: The authors have completed the STROBE reporting checklist. Available at https://vats.amegroups.com/article/view/10.21037/vats-24-25/rc

Data Sharing Statement: Available at https://vats.amegroups.com/article/view/10.21037/vats-24-25/dss

Peer Review File: Available at https://vats.amegroups.com/article/view/10.21037/vats-24-25/prf

Funding: None.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://vats.amegroups.com/article/view/10.21037/vats-24-25/coif). N.O. serves as an unpaid editorial board member of Video-Assisted Thoracic Surgery from April 2024 to December 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 or integrity of any part of the work are appropriately investigated and resolved. The study was conducted in accordance with the Declaration of Helsinki (as revised in 2013). The study was approved by the Ethics Review Board for Clinical Studies at Osaka University (No. 10026-3), and individual consent was waived because of its retrospective nature.

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/.

References

1. Gonzalez-Rivas D, de la Torre M, Fernandez R, et al. Single-port video-assisted thoracoscopic left upper lobectomy. Interact Cardiovasc Thorac Surg 2011;13:539-41. [Crossref] [PubMed]
2. Hirai K, Takeuchi S, Usuda J. Single-incision thoracoscopic surgery and conventional video-assisted thoracoscopic surgery: a retrospective comparative study of perioperative clinical outcomes†. Eur J Cardiothorac Surg 2016;49:i37-41. [PubMed]
3. Homma T, Shimada Y, Tanabe K. Decreased postoperative complications, neuropathic pain and epidural anesthesia-free effect of uniportal video-assisted thoracoscopic anatomical lung resection: a single-center initial experience of 100 cases. J Thorac Dis 2022;14:3154-66. [Crossref] [PubMed]
4. Li T, Xia L, Wang J, et al. Uniportal versus three-port video-assisted thoracoscopic surgery for non-small cell lung cancer: A retrospective study. Thorac Cancer 2021;12:1147-53. [Crossref] [PubMed]
5. Yan Y, Huang Q, Han H, et al. Uniportal versus multiportal video-assisted thoracoscopic anatomical resection for NSCLC: a meta-analysis. J Cardiothorac Surg 2020;15:238. [Crossref] [PubMed]
6. Yang X, Li M, Yang X, et al. Uniport versus multiport video-assisted thoracoscopic surgery in the perioperative treatment of patients with T1-3N0M0 non-small cell lung cancer: a systematic review and meta-analysis. J Thorac Dis 2018;10:2186-95. [Crossref] [PubMed]
7. Xiang Z, Wu B, Zhang X, et al. Uniportal versus multiportal video-assisted thoracoscopic segmentectomy for non-small cell lung cancer: a systematic review and meta-analysis. Surg Today 2023;53:293-305. [Crossref] [PubMed]
8. Vieira A, Bourdages-Pageau E, Kennedy K, et al. The learning curve on uniportal video-assisted thoracic surgery: An analysis of proficiency. J Thorac Cardiovasc Surg 2020;159:2487-2495.e2. [Crossref] [PubMed]
9. Wang B, Yao L, Sheng J, et al. Feasibility and safety of uniportal thoracoscopy for chronic pulmonary aspergillosis. Sci Rep 2023;13:16480. [Crossref] [PubMed]
10. Delgado Roel M, Fieira Costa EM, González-Rivas D, et al. Uniportal video-assisted thoracoscopic lymph node dissection. J Thorac Dis 2014;6:S665-8. [PubMed]
11. Shen Y, Wang H, Feng M, et al. Single- versus multiple-port thoracoscopic lobectomy for lung cancer: a propensity-matched study†. Eur J Cardiothorac Surg 2016;49:i48-53. [PubMed]
12. Ruan Y, Cao W, Xue H, et al. Long-term outcome of uniport vs. multiport video-assisted thoracoscopic lobectomy for lung cancer. Sci Rep 2024;14:5316. [Crossref] [PubMed]
13. Harris CG, James RS, Tian DH, et al. Systematic review and meta-analysis of uniportal versus multiportal video-assisted thoracoscopic lobectomy for lung cancer. Ann Cardiothorac Surg 2016;5:76-84. [Crossref] [PubMed]
14. Nachira D, Congedo MT, Tabacco D, et al. Surgical Effectiveness of Uniportal-VATS Lobectomy Compared to Open Surgery in Early-Stage Lung Cancer. Front Surg 2022;9:840070. [Crossref] [PubMed]
15. Liu J, Zhang X, Li J. Uniportal VATS lobectomy versus thoracotomy lobectomy for NSCLC larger than 5 cm: A propensity score-matched study. Thorac Cancer 2023;14:489-96. [Crossref] [PubMed]
16. Bertolaccini L, Batirel H, Brunelli A, et al. Uniportal video-assisted thoracic surgery lobectomy: a consensus report from the Uniportal VATS Interest Group (UVIG) of the European Society of Thoracic Surgeons (ESTS). Eur J Cardiothorac Surg 2019;56:224-9. [Crossref] [PubMed]
17. Gonzalez-Rivas D, Yang Y, Sekhniaidze D, et al. Uniportal video-assisted thoracoscopic bronchoplastic and carinal sleeve procedures. J Thorac Dis 2016;8:S210-22. [PubMed]
18. Zhang Z, Yuan F, Yin R, et al. Left upper lobectomy with bronchoplasty in uniportal video-assisted thoracic surgery for bronchial carcinoid. J Vis Surg 2016;2:84. [Crossref] [PubMed]
19. Wu L, Wang H, Cai H, et al. Comparison of Double Sleeve Lobectomy by Uniportal Video-Assisted Thoracic Surgery (VATS) and Thoracotomy for NSCLC Treatment. Cancer Manag Res 2019;11:10167-74. [Crossref] [PubMed]
20. Gonzalez-Rivas D, Fieira E, Delgado M, et al. Is uniportal thoracoscopic surgery a feasible approach for advanced stages of non-small cell lung cancer? J Thorac Dis 2014;6:641-8. [PubMed]
21. Fan J, Yao J, Wang Q, et al. Safety and feasibility of uniportal video-assisted thoracoscopic surgery for locally advanced non-small cell lung cancer. J Thorac Dis 2016;8:3543-50. [Crossref] [PubMed]