Pulmonary function protection by single-port thoracoscopic segmental lung resection in elderly patients with IA non-small cell lung cancer: A differential matched analysis

Abstract

In patients with stage IA non-small cell lung cancer (NSCLC), uniportal video-assisted thoracic surgery (U-VATS) anatomical segmentectomy removes the lung tumor while preserving lung function as much as possible, and it is therefore an alternative to lobectomy. Patients with stage IA NSCLC receiving U-VATS segmental resection at our institution from September 2017 to June 2019 were compared with patients receiving U-VATS lobectomy. A total of 47 patients received segmentectomy and 209 patients received U-VATS lobectomy in the same period. Propensity score matching was conducted to diminish bias. The final study cohort included 42 patients who received segmentectomy and 42 propensity score matching-matched patients who received lobectomy. Perioperative parameters and postoperative complications, length of hospital stay, postoperative forced expiratory volume in 1 s (FEV1), and forced vital capacity (FVC) were compared between the 2 groups. Surgery was successfully completed in all patients. The mean follow-up was for 8.2 months. The postoperative complication rate was comparable between the 2 groups: 31.0% in segmentectomy patients versus 35.7% in lobectomy patients (P = .643). At 1 month after surgery, FEV1% and FVC% were not significantly different between the 2 groups (P > .05). At 3 months after surgery, FEV1 and FVC were higher in segmentectomy patients than in lobectomy patients (FEV1, 82.79% ± 6.36% vs 78.55% ± 5.42%; FVC, 81.66% ± 6.09% vs 78.90% ± 5.58%, P < .05). Patients receiving segmentectomy suffer less pain and have better postoperative lung function and higher quality of life.

1. Introduction

Lung cancer is currently the foremost cause of carcinoma-related deaths in the world.^[1–3] For early-stage lung cancer, anatomical lobectomy and lymph node dissection were the preferred treatment. Currently, minimally invasive video-assisted thoracic surgery (VATS)^[4–6] is commonly adopted as it has several advantages over traditional open-chest surgery and thoracoscopic surgery: VATS is less invasive, causes less postoperative pain, enables faster postoperative recovery, and causes less damage to intercostal muscles, blood vessels, and nerves.^[7,8]

Segmental resection is an important approach to sublobar pneumonectomy and is used extensively for lung adenocarcinoma presenting as ground-glass opacity (GGO) on imaging.^[9] Anatomical lung segment resection can be difficult because of the complex and varied anatomy of the bronchi and blood vessels. Moreover, there is still no strong medical evidence of oncological benefit.

Lung nodule detection rates are increasing due to extensive use of computed tomography (CT) screening.^[10] A good proportion of identified nodules are early lung cancers, with many being in elderly patients with cardiopulmonary insufficiency and multiple comorbidities. Standard thoracoscopic lobectomy is often contraindicated in the elderly because of problems such as advanced age, poor cardiopulmonary reserve function, or comorbidities.

Because standard lobectomy removes more lung parenchyma than segmentectomy, loss of lung function is greater and postoperative recovery poorer.^[11,12] Uniportal VATS (U-VATS)^[13,14] is widely used for lung segmental resection in major centers, but the benefits of U-VATS lung segment resection versus U-VATS lobectomy with regard to immediate and long-term lung function recovery and postoperative quality of life (QoL) have not been fully investigated. The aim of this study was to compare the safety and short-term effectiveness of U-VATS anatomical segmental lung excision versus U-VATS lobectomy in patients with early-stage non-small cell lung cancer (NSCLC). The findings of this study will provide an evidence base for clinical management.

2. Methods

2.1. Ethics declaration

This research was authorized by the Ethics Review Board of the National Center for Health Statistics, and written permission was obtained from the participants in each case.

2.2. Patient selection and data collection

For this retrospective comparative study, 2 groups of patients with stage IA NSCLC were enrolled. The study group was selected from 47 patients who received U-VATS lung segment resection at the Second Affiliated Hospital of Nanchang University from September 2017 to June 2019. All patients were operated on by the same surgical team. The comparison group was selected from 209 patients who received U-VATS lobectomy during the same period. There were statistically significant differences between the 2 groups in age and tumor diameter, with the mean age being higher and the mean tumor diameter being lower in the lung segmentectomy group than in the lung lobectomy group. To balance the differences, 1:1 propensity score matching (PSM) was conducted using the nearest neighbor matching method. Finally, 84 matched patients (42 segmentectomy patients and 42 lobectomy patients) were selected to form the study population. Figure 1 summarizes the patient selection process, and Table 1 presents the data of the 2 PSM-matched groups.

Figure 1.

Flowchart of participant screening. Propensity score matching (PSM) was conducted to diminish bias.

Table 1.

General and clinicopathological characteristics of the patient.

Group	Patient general information				Patient information after PSM
	Lung segments (n = 47)	Lung lobes (n = 209)	t/χ2 value	P value	Lung segment (n = 42)	Lung lobes (n = 42)	t/χ2 value	P value
Age	65.36 ± 9.28	62.24 ± 7.49	2.463	.014	64.42 ± 8.77	64.19 ± 8.17	0.129	.898
Gender			0.598	.439			0.83	.362
Male	19	72			17	13
Female	28	137			25	29
Tumor diameter	1.23 ± 0.40	1.54 ± 0.81	2.564	.011	1.29 ± 0.47	1.42 ± 0.61	1.405	.164
Preoperative pulmonary function
FEV1%	91.52 ± 10.58	91.05 ± 10.35	0.281	.779	91.33 ± 10.13	91.18 ± 10.84	0.066	.948
FVC%	91.32 ± 9.52	90.83 ± 9.04	0.345	.73	91.24 ± 9.40	91.4 ± 9.42	0.081	.936
Tumor location			4.333	.363			0.211	.976
Upper lobe of right lung	16	87			16	15
Middle lobe of right lung	0	8			0	0
Lower lobe of the right lung	8	31			8	9
Upper lobe of the left lung	13	56			11	12
Lower lobe of the left lung	10	27			7	6
Pathological type			3.508	.32			0.311	.856
Lung adenocarcinoma	41	169			34	32
Squamous lung cancer	4	36			7	9
Large cell lung cancer	1	3			1	1
Adenosquamous carcinoma of the lung	1	1			0	0
TNM stages			5.068	.079			0.198	.657
ⅠA1	19	65			16	14
ⅠA2	28	126			26	28
ⅠA3	0	18			0	0

FEV1 = forced expiratory volume in 1 s, FVC = forced vital capacity, PSM = propensity score matching.

2.3. Inclusion criteria

Inclusion criteria were according to the International Association for the Study of Lung Cancer, 8th edition, TNM staging standards^[15–17]; patients were eligible for inclusion if CT or positron emission tomography-CT showed pulmonary nodules or pure GGO or mixed GGO; maximum lesion diameter was ≤3 cm; postoperative pathological examination showed stage IA NSCLC (PT1a-cN0M0) or adenocarcinoma in situ; and the procedure was performed through single-port thoracoscopy.

2.4. Exclusion criteria

Patients were excluded if they had a poor cardiopulmonary function and were unfit for surgery; there was preoperative history of radiotherapy or severe thoracic adhesions, making thoracoscopic surgery impossible; or there was intraoperative need for the open-chest approach or multiple ports due to intraoperative bleeding or other causes.

2.5. Observed indicators

The intraoperative and postoperative parameters (operative time, intraoperative bleeding, total postoperative drainage, postoperative extubation time, postoperative hospital stay), postoperative pain VAS scores (VAS scores at 24 hours, 48 hours, 72 hours, and 5 days postoperatively), postoperative lung function (FEV1%, forced vital capacity [FVC]%) at 1 month and 3 months, postoperative complication rate (%) and postoperative QoL scores (at 1 month and 3 months postoperatively) were observed in patients in the U-VATS lung segment and lung lobe groups. The (%) and postoperative QOL scores (at 1 month and 3 months postoperatively).

The pain levels of postoperative patients were scored using the VAS scoring method (numerical scoring method), divided into 4 levels with scores from 0 to 10. The higher the score, the more intense the pain, as follows: 0: no pain; 1 to 3: mild pain, tolerable; 4 to 6: moderate pain, sleep affected, but tolerable; 7 to 10: severe pain, affecting eating and sleeping, unbearable.

For the QOL scoring standard, according to the draft oncology patient life score developed in China, 12 aspects including diet, sleep, pain, and daily life condition are scored. The total score is 60 points divided into 5 grades, with the following grading criteria: ≤20 points: very poor QoL; 21 to 30 points: poor QoL; 31 to 40 points: average QoL; 41 to 50 points: good QoL; 51 to 60 points: good QoL.

2.6. Preoperative surgical plan and 3D reconstruction

Preoperative chest CT data (≤1 mm slices) were imported into Mimics, Deepinsight, or other software for 3D reconstruction of the bronchi, pulmonary arteries, and veins, and to measure the maximum diameter of the tumor and the dimensions of the involved bronchopulmonary segment. Vascular and bronchial variations were identified, and the anatomical connections of the lung tumor to neighboring vessels and bronchi were marked. The extent of the incision margin was simulated; the incision margin was kept 2 cm away from the tumor to ensure a safe margin and reduce the risk of recurrence. The range of segmentectomy was according to the results of 3D reconstruction: if the lesion was limited to a single lung segment, lung segment resection was performed, and if the lesion involved ≥2 target segments, combined segment resection was performed. Preoperative planning of the surgical approach through 3D-CT bronchial angiography (3D-CTBA)^[18–20] simulation is more accurate than traditional localization methods (e.g., by visual and tactile) and helps avoid injury, saves surgical time, and improves surgical efficiency (Fig. 2).

Figure 2.

Precise resection of the right S1 + S2 segment guided by real-time 3D reconstruction. “A” indicates an artery, “B” indicates a bronchus, and “V” indicates a vein. (a) CT scan shows a GGO lesion between S1 and S2 on the right side. (b) 3D image at the location of the lesion. The bronchial (c), pulmonary vein, (d) and pulmonary artery (e) branches of the target segment were identified by real-time guidance of 3D reconstruction. CT = computed tomography, GGO = ground-glass opacity.

2.7. Thoracoscopic procedure

In lung segmentectomy patients, a single surgical port of size 3.0 cm was made in the 5th intercostal space either in the mid-axillary or the posterior axillary line. Intraoperatively, the arteries and veins were ligated with tailored sutures, silk sutures, vascular clamps, and bronchi with a cutting stapler. The intersegmental plane was determined by using the “inflation–deflation method,^[21]” indocyanine green fluoroscopic thoracoscopic identification, or selective high-frequency ventilation of the target lung segment under bronchoscopy, depending on the preoperative preparation and intraoperative situation. The intersegmental plane was cut using the dimensional reduction method,^[22] using high-frequency electrocoagulation in combination with a cutting closure device. The surface of the cut lung was covered with polyglycolic acid (sheet) and Fibrin sealant to decrease the risk of postoperative air leakage.

In lung lobectomy patients, a single operating port of approximately 3.0 cm in length was made in the 5th intercostal space in the posterior axillary line or the mid-axillary line. The surgical anatomical sequence was: pulmonary fissure, artery, bronchus, and pulmonary vein. If the pulmonary fissure was underdeveloped, the “tunnel method” was used, that is, a tunnel was formed by bluntly separating the pulmonary fissure from the anterior and posterior mediastinum with a vascular clamp; the tunnel was then treated with a cutting closure device.

The standard procedures for lymph node dissection and postoperative drainage tube placement were used in both groups.

3. Results

Surgery was completed successfully in all 84 patients (30 males, 54 females). Baseline characteristics were similar in the 2 groups (Table 1). Table 2 shows the types of VATS segmentectomy. Mean follow-up was for 8.2 months (range, 4–20 months). No patient died or had tumor recurrence during follow-up.

Table 2.

Surgical sites in the lung segment group and lobe group.

Group	Lung segment (n = 42)	Lung lobes (n = 42)
Upper lobe of right lung		15
S1	6
S2	3
S3	7
Lower lobe of right lung		9
S6	3
S7	1
S8 + 9	1
S10	2
S7−10	1
Upper lobe of left lung		12
S1 + 2	6
S1 + 2+3	2
S4 + 5	3
Lower lobe of left lung		6
S6	3
S7 + 8	2
S9 + 10	1
S7−10	1

Complex segmentectomy: “S” indicates lung segment. Right S^8 + 9, S⁷⁻¹⁰; left S^1 + 2, S^1 + 2+3, S^4 + 5, S^7 + 8, S^9 + 10, S⁷⁻¹⁰.

In lung segmentectomy patients, mean extubation time was 4.76 ± 0.97 days, mean total postoperative drainage was 680.33 ± 75.47 mL, and mean duration of postoperative hospital stay was 5.45 ± 1.20 days. In lobectomy patients, mean extubation time was 5.31 ± 1.06 days, mean total postoperative drainage was 722.14 ± 87.30 mL, and mean duration of postoperative hospital stay was 6.02 ± 1.22 days. In all 3 parameters, the lung segmentectomy group was superior to the lobectomy group (all P < .05). However, mean operative time was significantly longer in segmentectomy patients than in lobectomy patients (165.10 ± 32.91 minutes vs 150.76 ± 26.49 minutes, P < .031). Other clinical parameters were comparable between the 2 groups (Table 3).

Table 3.

Intraoperative and postoperative clinical indexes.

Group	Lung segment (n = 42)	Lung lobes (n = 42)	t/χ2 value	P value
Operation time (min)	165.10 ± 32.91	150.76 ± 26.49	2.199	.031
Intraoperative bleeding (mL)	125.95 ± 20.18	133.81 ± 32.62	1.312	.194
Total postoperative drainage (mL)	680.33 ± 75.47	722.14 ± 87.30	2.292	.024
Postoperative extubation time (d)	4.76 ± 0.97	5.31 ± 1.06	2.442	.017
Postoperative hospital stay (d)	5.45 ± 1.20	6.02 ± 1.22	2.135	.036

Patients in the lung segment group had a 24-hour postoperative VAS score [(5.02 ± 0.81) versus (5.71 ± 0.86), P < .001], 48 hours VAS score [(6.48 ± 0.95) vs (6.95 ± 1.07), P < .001], 72 hours VAS score [(3.14 ± 0.64) vs (3.79 ± 0.80), P < .001], and 5th-day VAS score [(1.86 ± 0.56) vs (2.43 ± 0.73), P < .001], were statistically lower than those of the pulmonary lobe group (P < .05). The patients in both groups reached the peak value of pain level at 48 hours postoperatively, and there was a significant improvement in pain level at 72 hours and 5th day postoperatively compared to 24 hours and 48 hours (Table 4).

Table 4.

Comparison of postoperative VAS score between the lung segment and lobe groups.

Group	Postoperative 24 h pain score	Postoperative 48 h pain score	Postoperative 72 h pain score	Postoperative 5 d pain score
Lung segment (n = 42)	5.02 ± 0.81	6.48 ± 0.95*	3.14 ± 0.64**	1.86 ± 0.56***
Lung lobes (n = 42)	5.71 ± 0.86	6.95 ± 1.07*	3.79 ± 0.80**	2.43 ± 0.73***
t value	3.777	4.053	4.012	3.984
P value	P < .001	P < .001	P < .001	P < .001

Compared with 24 h postoperative,

^*P > .05; compared with 48 h postoperative,

^**P < .05; compared with 72 h postoperative,

^***P < .05.

Postoperative complications included pneumonia, postoperative air leak for >3 days, pulmonary atelectasis, atrial fibrillation, pyothorax, and hoarseness. The complication rate was not significantly different between the 2 groups (31.0% in segmentectomy patients vs 35.7% in lobectomy patients, P = .643). All complications were resolved with pharmacotherapy, nursing care, endoscopic treatment, and nutritional support (Table 5).

Table 5.

Incidence of postoperative complications.

Group	Lung segment (n = 42)	Lung lobes (n = 42)	t/χ2 value	P value
Pneumonia	8 (19.0%)	7 (16.7%)	0.081	.776
Postoperative air leakage > 3 d	4 (9.5%)	3 (7.1%)	0.156	.693
Atelectasis	2 (4.8%)	4 (9.5%)	0.718	.397
Atrial fibrillation	1 (2.4%)	2 (4.8%)	0.364	.557
Empyema	0	1 (2.4%)	1.012	.314
Hoarseness	0	1 (2.4%)	1.012	.314
Total	13x (31.0%)	15y (35.7%)	0.214	.643

x = 2 patients in the lung segment group had 2 concurrent complications (1 pneumonia combined with air leakage and 1 pneumonia combined with atelectasis); y = 3 patients in the pulmonary lobe group had 2 concurrent complications (1 pneumothorax combined with pneumonia, 1 pneumonia combined with atrial fibrillation, and 1 pulmonary air leak combined with pulmonary atelectasis).

One month after surgery, FEV1 and FVC were not significantly different between segmentectomy and lobectomy patients (FEV1, 75.23% ± 6.95% vs 73.72% ± 5.66%, P = .281; FVC, 75.15% ± 6.10% vs 72.86% ± 5.08%, P = .067). However, at 3 months after surgery, FEV1 and FVC were significantly higher in segmentectomy patients than in lobectomy patients (FEV1, 82.79% ± 6.36% vs 78.55% ± 5.42%, P = .001; FVC, 81.66% ± 6.09% vs 78.90% ± 5.58%, P = .033; Table 6).

Table 6.

Comparison of FEV1% and FVC% preoperatively and at 1 month and 3 months postoperatively.

Group	FEV1%			FVC%
	Preoperative	Postoperative		Preoperative	Postoperative
		1 mo	3 mo		1 mo	3 mo
Lung segment (n = 42)	91.33 ± 10.13	75.23 ± 6.95	82.79 ± 6.36	91.24 ± 9.40	75.15 ± 6.10	81.66 ± 6.09
Lung lobes (n = 42)	91.24 ± 9.40	73.72 ± 5.66	78.55 ± 5.42	91.40 ± 9.42	72.86 ± 5.08	78.90 ± 5.58
t/χ2 value	0.066	1.085	3.285	0.081	1.854	2.17
P value	.948	.281	.001	.936	.067	.033

FEV1 = forced expiratory volume in 1 s, FVC = forced vital capacity.

As Table 7 shows, postoperative QoL scores at 1 month and 3 months after surgery were significantly better in segmentectomy patients than in lobectomy patients: 42.29 ± 5.78 versus 39.60 ± 5.45 (P = .033) at 1 month and 48.02 ± 6.45 versus 43.71 ± 6.04 (P = .002) at 3 months.

Table 7.

Comparison of quality of life scores (QOL) at 1 month and 3 months after surgery in the lung segment and lobe groups.

Group	Preoperative score	1 mo after surgery	3 mo after surgery
Lung segment (n = 42)	31.12 ± 4.22	42.29 ± 5.78*	48.02 ± 6.45**
Lung lobes (n = 42)	32.52 ± 4.99	39.60 ± 5.45*	43.71 ± 6.04**
t value	1.376	2.169	3.123
P value	.173	.033	.002

^*P < .05 compared with preoperative QOL scores.

^**P < .05 compared with 1 month postoperatively.

4. Discussion

Lung cancer is the most commonly diagnosed malignancy in the world and the most common cause of cancer death.^[23] Early-stage lung cancer is not easy to detect because of the absence of specific clinical manifestations. By the time clinical manifestations such as chest pain, irritating cough, hemoptysis, blood in sputum, chest tightness, dyspnea, and weight loss appear, cancer will have advanced, and lymphatic and blood-borne metastasis will likely be present.^[24] In recent years, increased awareness among the population and advances in medical imaging technology have resulted in more and more cases of early-stage lung cancer being detected. With prompt surgical treatment, the 5-year survival rate of patients with early-stage NSCLC (stage IA-IIB) ranges from 50 to 80%. For operable NSCLC, lung lobectomy plus mediastinal lymph node clearance are the gold standard therapy. Pulmonary segmental resection was first reported in 1939 and was initially used for patients with lung adenocarcinoma presenting as GGO.^[25] In recent decades, thoracic surgeons have found that lung segmental resection in some subsets of patients (e.g., elderly lung cancer survivors with poor respiratory reserve capacity or patients with a previous history of lung resection) is comparable to lobectomy in terms of long-term survival, but is superior in terms of lung function preservation and postoperative QoL.^[26,27] In 2011, Gonzalez-Rovas et al^[28] published the first report on single-port thoracoscopic lobectomy, a technique that has since become popular with thoracic surgeons as they become more proficient in thoracoscopic surgery and the use of new surgical instruments. In a prospective study, Xu et al^[29] showed that compared with 3-port thoracoscopy, single-port thoracoscopy is associated with faster postoperative recovery, shorter hospital stay, better postoperative QoL, and better cosmetic outcome. However, some aspects of single-port anatomic segmental lung resection remain controversial, and further study is therefore warranted.

Gonzalez-Rivas et al^[30] used U-VATS lung segment resection for the treatment of 17 patients with a mean maximum tumor diameter of 2.3 ± 1.0 cm and reported a mean operative time of 94 ± 35.0 minutes. In the present study, the mean tumor diameter was 1.70 ± 1.1 cm, and the mean operative time was 165.10 ± 32.91 minutes. The markedly longer operative time in the present study is due to the use of the inflation–deflation method to determine the intersegmental plane.

The incidence of postoperative complications reflects the safety and feasibility of the operation. In a retrospective study, Bédat et al^[31,32] found similar postoperative complication rates in lung segmentectomy patients and lung lobectomy patients (33.3% vs 38.0%, P = .73). In the present study, also, the postoperative complication rate was similar in the 2 groups: 31.0% in the lung segmentectomy group versus 35.7% in the lung lobectomy group (P = .643).

In the present study cohort, there were 15 cases of pneumonia, but all were resolved with antibiotics and supportive treatment (analgesics and airway management). Prolonged (>3 days) postoperative air leak occurred in 7 patients, all of whom were successfully managed with negative pressure continuous aspiration to promote lung re-expansion, intrathoracic injection of hypertonic (50%) glucose or autologous blood to promote chest adhesions, and supportive treatment. All 7 patients were discharged after CT confirmed good lung re-expansion. The 3 patients who developed atrial fibrillation were successfully treated with deslanoside (to strengthen myocardial contraction and reduce heart rate), amiodarone (to restore sinus rhythm), continuous low-flow oxygen (to correct hypoxia), and other measures such as correction of fluid–electrolyte imbalance and supportive treatment. The 6 patients who had pulmonary atelectasis recovered with bedside aspiration, bronchoscopic aspiration, and respiratory function exercises. One patient in the lung lobectomy group developed a chest abscess, but it resolved within 12 days with chest drainage, antibiotics, and nutritional support. One patient in the lung lobectomy group developed hoarseness due to damage to the left recurrent laryngeal nerve during removal of the 4L lymph node. No other serious complications (infection, bronchopleural fistula, and so on) occurred in either group.

Theoretically, anatomic segmental lung resection has an advantage over lobectomy in terms of preservation of lung parenchyma; this is especially beneficial in elderly patients with poor lung function. Kim et al^[33] reported that FEV1 and FVC were better in segmentectomy patients than in lobectomy patients at 3 and 12 months after surgery. A meta-analysis by Charloux et al^[34] showed that the decrease in postoperative lung function was significantly lower in segmentectomy patients than in lobectomy patients; the difference was particularly noticeable for FEV1, which decreased by 2 to 7% (mean, 5%) in segmentectomy patients versus 8 to 13% (mean, 11%) in lobectomy patients at 12 months after surgery. In the present study, FEV1 and FVC at 3 months after surgery were significantly superior in lung segmentectomy patients than in lung lobectomy patients (P < .05). Thus, U-VATS segmental lung resection is obviously superior to the lobar resection in terms of lung function preservation. We believe that there may be the following reasons for this phenomenon. First, the previous treatment for early-stage lung cancer was mostly done by open-heart surgery, which causes a lot of damage to the chest wall and may lead to restrictive ventilatory dysfunction after surgery, which may overshadow the protection of lung function by lung segmental resection. And lung segment resection is less damaging compared to lobectomy. Second, the original pulmonary function tests were crude and may not reflect the slight pulmonary function benefit.

In this study, total postoperative drainage was less and chest tube removal earlier in segmentectomy patients than in lobectomy patients; segmentectomy thus allowed earlier resumption of ambulatory activities and promoted postoperative recovery, and reduced length of hospital stay and the economic burden on patients. Performing 3D-CTBA on patients preoperatively can effectively shorten the procedure time, and the images can provide guidance to the thoracic surgeon during the procedure. Compared to traditional diagnostic angiography, 3D-CTBA is much less invasive and has essentially no side effects or complications.

The present study has some limitations. First, it was retrospective research and although PSM was used to reduce selection bias, it was not completely eliminated. Because the number of comparisons between the 2 groups of patients is greatly reduced after PSM matching is performed, this may reduce the statistical power. Second, the operator learning curve may have resulted in some differences in surgery-related indicators. Third, the follow-up period was too short to assess long-term local recurrence rate, including tumor-free survival, 5-year survival rate, and long-term deterioration in lung function. Finally, because pain scales are subjective, pain scoring systems are unreliable, and the VAS may add another level of inaccuracy.

5. Conclusion

U-VATS lung segment resection is comparable to lobectomy in terms of short-term effectiveness. While both procedures are safe and effective, patients undergoing segmentectomy suffer less pain and have better postoperative lung function and higher postoperative QoL. Segmentectomy is therefore the more suitable option for early-stage NSCLC in older people with poor lung function.

Acknowledgments

We would like to gratefully acknowledge the time and effort of the participants during the data collection phase.

Author contributions

Conceptualization: Linmin Xiong, Silin Wang, Yiping Wei, Dongliang Yu.

Data curation: Linmin Xiong, Silin Wang, Xinle Zhang, Dongliang Yu.

Formal analysis: Linmin Xiong, Silin Wang.

Investigation: Heng Chen, Kang Zhu.

Methodology: Yiping Wei, Dongliang Yu.

Project administration: Jianwen Xiong.

Resources: Yonggang Shi, Heng Chen.

Software: Yonggang Shi, Heng Chen, Jianwen Xiong, Yelin Zhang.

Supervision: Xinle Zhang, Yelin Zhang.

Writing – original draft: Linmin Xiong, Silin Wang.

Writing – review & editing: Linmin Xiong, Silin Wang, Yiping Wei, Dongliang Yu.