The Impact of Segmentectomy Versus Lobectomy on Pulmonary Function in Patients With Non-small-cell Lung Cancer: a Meta-analysis

The Impact of Segmentectomy Versus Lobectomy on Pulmonary Function in Patients With Non-small-cell Lung Cancer: a Meta-analysis | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research article The Impact of Segmentectomy Versus Lobectomy on Pulmonary Function in Patients With Non-small-cell Lung Cancer: a Meta-analysis Yuan Xu, Yingzhi Qin, Dongjie Ma, Hongsheng Liu This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-1048811/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 7 You are reading this latest preprint version Abstract Objective: Segmentectomy has been reported as an alternative to lobectomy for small-sized NSCLC without detriment to survival. The long-term benefits of segmentectomy over lobectomy on pulmonary function have not been firmly established. This meta-analysis aims to compare postoperative changes in pulmonary function in NSCLC patients undergoing segmentectomy or lobectomy. Methods: Medline, Embase, Web of Science and Scopus were searched through March 2021. Statistical comparisons were made when appropriate. Results: Fourteen studies (2412 participants) out of 324 citations were included in this study. All selected studies were high quality, as indicated by the Newcastle–Ottawa scale for assessing the risk of bias. Clinical outcomes were compared between segmentectomy and lobectomy. ΔFEV1 [10 studies, P<0.01, WMD = 0.40 (0.29, 0.51)], ΔFVC [4 studies, P<0.01, WMD = 0.16 (0.07, 0.24)], ΔFVC% [4 studies, P<0.01, WMD = 4.05 (2.32, 5.79)], ΔFEV1/FVC [2 studies, P<0.01, WMD = 1.99 (0.90, 3.08)], and ΔDLCO [3 studies, P<0.01, WMD = 1.30 (0.69, 1.90)] were significantly lower in the segmentectomy group than in the lobectomy group. Subgroup analysis showed that in stage IA patients, the ΔFEV1% [3 studies, P<0.01, WMD = 0.26 (0.07, 0.46)] was significantly lower in the segmentectomy group. The ΔDLCO% and ΔMVV% were incomparable. Conclusion: Segmentectomy preserves more lung function than lobectomy. There were significantly smaller decreases in FEV1, FVC, FVC%, FEV1/FVC and DLCO in the segmentectomy group than in the lobectomy group. Cardiothoracic Surgery non-small-cell lung cancer segmentectomy lobectomy pulmonary function Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Introduction Lung cancer is one of the leading cause of cancer-related death worldwide ( 1 ). Surgical resection for non-small-cell lung cancer (NSCLC) is the standard treatment that leads to the best chance of a cure. For the 100-year history of surgery, lobectomy has remained the gold standard for operable NSCLC. In recent years, segmentectomy has been reported as an alternative to lobectomy for small-sized NSCLC without detriment in survival ( 2 ). Theoretically, segmentectomy has an advantage over lobectomy on anatomical functional. However, the long-term benefits of segmentectomy over lobectomy on pulmonary function have not been firmly established. Reports related to the utility of segmentectomy in preserving lung function are conflicting. The purpose of this study was to perform a meta-analysis to compare postoperative changes in pulmonary function in NSCLC patients undergoing segmentectomy or lobectomy. Methods Inclusion and Exclusion Criteria Studies were included if they met the following inclusion criteria: ( 1 ) patients diagnosed with NSCLC underwent surgical treatment; ( 2 ) comparative data between segmentectomy and lobectomy were available; and ( 3 ) preoperative and postoperative pulmonary function data were available. The outcomes included forced expiratory volume in 1 second (FEV1), predicted FEV1 percentage (FEV1%), forced vital capacity (FVC), predicted FVC percentage (FVC%), FEV1/FVC, maximal voluntary ventilation (MVV), diffusion capacity of carbon monoxide (DLCO) and predicted DLCO percentage (DLCO%). Studies were excluded if the full text was not in English or could not be accessed. Search Strategy Medline, Embase, Web of Science and Scopus were searched through May 2021. The following search terms and strategies were used: ( 1 ) respiratory function OR pulmonary function OR FEV1 OR FVC OR MVV OR DLCO; ( 2 ) lung cancer; ( 3 ) lobectomy AND (segmentectomy OR sublobar resection OR limited resection), and ( 1 ) AND ( 2 ) AND ( 3 ). Data were extracted with a standardized form. The Newcastle–Ottawa Scale (NOS) was used for quality assessment. Statistical Analysis Inconsistency between studies was quantified by calculating the I 2 statistic. Continuous variables were reported as weighted mean differences (WMDs) and 95% confidence intervals (95% CIs). A random-effects model was used for heterogeneous data (I 2 >50%), whereas a fixed-effects model was used for homogenous data (I 2 <50%). P<0.05 was considered to be statistically significant. SAS software, version 9.1 (SAS Institute, Cary, NC, USA) and Review Manager, version 5.4 (The Cochrane Collaboration) were used to perform statistical analysis. Results Search Results The initial database search identified 172 articles in Medline, 251 in Embase, 154 in Web of Science and 166 in Scopus. After excluding duplicate records, 324 studies were included. A total of 273 articles were excluded because they failed to meet the inclusion criteria after review of the abstracts and titles. An additional 37 articles were excluded after the full text review. Hence, a total of 14 studies (13 retrospective and 1 prospective observational) including 2412 patients (976 sublobar resection and 1436 lobectomy) were finally selected. The detailed selection process is shown in Figure 1 . The major characteristics of the participants in the included studies are shown in Table 1 . Patients in 8 studies had NSCLC with TNM stage I. Six studies included the VATS approach only, 2 included the open approach only, and 3 included both. Two studies included wedge resections. The follow-up time (from surgery to postoperative pulmonary function) ranged from 3 to 60 months. Table 1 Basic characteristics of the included studies. ID Location Enrolment Year Total No. No. of segmentectomy TNM stage Approach Wedge resection included Involved lobe Follow-up (month) Upper Middle Lower Kim 2015 (22) Korea 2003-2012 300 73 I-IV VATS yes NM 3&12 Zhong 2020 (24) China 2014-2016 144 68 IA-IB VATS no 35 9 24 6 37 11 28 Nomori 2018c Japan 2013-2016 206 103 NM VATS+open no 57 0 46 6 57 0 46 Takizawa 1999 (25) Japan 1993-1996 80 40 IA open no 25 0 15 12 28 0 12 Tane 2019 (3) Japan 2012-2017 148 74 IA1-IA2 VATS no 45 0 29 6 45 0 29 Helminen 2020 (1) Japan 2007-2019 215 105 I-III VATS no NM NM Gu 2018 (26) China 2011-2014 109 34 IA VATS yes 23 0 11 6 50 0 25 Kobayashi 2017 (18) Japan 2001-2009 346 118 I-III VATS+open no NM 12 & 60 Keenan 2004 (4) USA 1996-2001 201 54 IA NM no 23 0 31 12 87 17 43 Kashiwabara 2009 (16) Japan 2000-2006 118 71 I NM no 38 0 33 6 32 0 15 Macke 2015 (14) USA 1996-2001 159 77 I VATS+open no 36 9 32 6-36 48 0 34 Saito 2014 (27) Japan 2006-2012 178 52 I open no 30 0 22 6 71 6 49 Yoshimoto 2010 (28) Japan 2005-2008 20 13 NM NM no 13 0 0 5 7 0 0 Hwang 2015 (21) Korea 2005-2013 188 94 I-IV VATS no NM NM NM, not mentioned; VATS, video-assisted thoracoscopic surgery. Quality Assessment The quality of the included studies was assessed using the NOS ( www.ohri.ca/programs/clinical_epidemiology/oxford.htm ). Two independent reviewers conducted the assessment. Disagreements were resolved by discussion. Of the studies, seven scored 9 points, four scored 8 points, two scored 7 points, and one scored 6 points, indicating that all the studies had relatively high quality (Table 2 ). Table 2 Quality assessment according to the Newcastle–Ottawa scale. ID Selection Comparability Exposure Total score Kim 2015 (22) 3 2 3 8 Zhong 2020 (24) 4 2 2 8 Nomori 2018 (7) 4 2 3 9 Takizawa 1999 (25) 4 2 3 9 Tane 2019 (3) 4 2 3 9 Helminen 2020 (1) 3 2 2 7 Gu 2018 (26) 4 2 3 9 Kobayashi 2017 (18) 4 2 3 9 Keenan 2004 (4) 2 1 3 6 Kashiwabara 2009 (16) 4 2 3 9 Macke 2015 (14) 4 2 3 9 Saito 2014 (27) 4 1 3 8 Yoshimoto 2010 (28) 3 2 2 7 Hwang 2015 (21) 4 2 2 8 Clinical Outcomes FEV1 & FEV1% FEV1 was the most frequently reported functional value. It was recorded in 10 studies (n = 1664, I 2 = 95%, random-effects model, Figure S1). The mean ΔFEV1 varied from −0.10 to -0.44 (segmentectomy group) and -0.23 to -0.50 (lobectomy group). After ruling out one study with high heterogeneity ( 3 ), the ΔFEV1 was significantly lower in the segmentectomy group than in the lobectomy group [P<0.01, WMD = 0.40 (0.29, 0.51); heterogeneity: Chi 2 = 7.45, df = 8, P = 0.49; I 2 = 0%, fixed-effects model; Figure 2 ]. The FEV1% was incomparable due to the high heterogeneity (8 studies, n=1633, I 2 = 96%, random-effects model, Figure S2). The mean ΔFEV1% varied from -9.2% to +1.0% (segmentectomy group) and -16.2% to -8.1% (lobectomy group). Subgroup analysis showed that in stage IA patients, the ΔFEV1% was significantly lower in the segmentectomy group [3 studies, n=427; P<0.01, WMD = 0.26 (0.07, 0.46); heterogeneity: Chi 2 = 2.13, df = 2, P = 0.35; I 2 = 6%, fixed-effects model; Figure 3 ]. FVC & FVC% Four studies (n = 607) provided FVC values. The mean ΔFVC varied from −0.07 to -0.46 (segmentectomy group) and -0.23 to -0.6 (lobectomy group). The ΔFVC was significantly lower in the segmentectomy group than in the lobectomy group [P<0.01, WMD = 0.16 (0.07, 0.24); heterogeneity: Chi 2 = 0.38, df = 3, P = 0.94; I 2 = 0%, fixed-effects model; Figure 4 ]. The FVC% was reported in 4 studies (n = 725, I2 = 79%, random-effects model, Figure S3). After ruling out one study with high heterogeneity ( 4 ), the ΔFVC% was significantly lower in the segmentectomy group than in the lobectomy group [P<0.01, WMD = 4.05 (2.32, 5.79); heterogeneity: Chi 2 = 0.70, df = 2, P = 0.71; I 2 = 0%, fixed-effects model; Figure 5 ]. The ΔFVC% varied from -1.5% to -10.5% in the segmentectomy group and -4.4% to -13.7% in the lobectomy group. Other outcomes The ΔFEV1/FVC was significantly lower in the segmentectomy group than in the lobectomy group [2 studies, n=646; P<0.01, WMD = 1.99 (0.90, 3.08); heterogeneity: Chi 2 = 0.48, df = 1, P = 0.49; I 2 = 0%, fixed-effects model; Figure 6 ]. The ΔFEV1/FVC varied from -0.3 to -1.9 in the segmentectomy group and -1.8 to -4.2 in the lobectomy group. Similarly, the ΔDLCO was significantly lower in the segmentectomy group [3 studies, P<0.01, WMD = 1.30 (0.69, 1.90); heterogeneity: Chi 2 = 2.92, df = 2, P = 0.23; I 2 = 31%, fixed-effects model; Figure 7 ]. The ΔDLCO varied from -0.07 to -2.6 in the segmentectomy group and -1.8 to -3 in the lobectomy group. The ΔDLCO% (n = 660, I 2 = 96%, random-effects model, Figure S4) and ΔMVV% (n = 345, I 2 = 96%, random-effects model, Figure S5) were incomparable. Discussion Previous studies suggested that segmentectomy confers little functional advantage over lobectomy ( 4 ). It was concluded that lobectomy should remain the procedure of choice despite the slight functional advantage of limited resection. In the present study, we compared postoperative changes in pulmonary function in patients undergoing segmentectomy or lobectomy. This meta-analysis showed that there were significantly fewer decreases in FEV1, FVC, FVC%, FEV1/FVC and DLCO in the segmentectomy group than in the lobectomy group. Subgroup analysis also showed that the decrease in FEV1% was significantly less in the segmentectomy group in stage IA patients. Altogether, these studies support the assumption that segmentectomy preserves more lung function than lobectomy. Pulmonary function tests are recommended in all patients who undergo thoracic surgery ( 5 ). Theoretically, segmentectomy has an anatomical functional advantage over lobectomy. First, as the adult lung cannot regenerate new alveolar septal tissues, postoperative pulmonary function is mainly determined by the amount of lung resected. Second, anatomical excursion of the nonoperated lobe after lobectomy occurred. For example, a right upper lobectomy will damage the function of the middle lobe due to the kink of the middle lobar bronchus and pulmonary artery ( 6 ). Third, compensatory lung growth could already have occurred in the ipsilateral nonoperated lobe in the lobectomy group before the operation due to the decreased function in the operated lobe, resulting in less space for postoperative lung growth ( 7 ). FEV1 is an indicator of airway resistance. Changes in FEV1 are largely related to ventilation mechanisms, including existing airway obstruction, compensatory expansion of the residual lung, and chest wall activity ( 8 ). Lung resection will inevitably lead to displacement of the remaining lobe. The meta-analysis showed that the decrease in FEV1 was higher in the lobectomy group, indicating that lobectomy is more likely to increase airway resistance. Changes in the FVC are mainly determined by the amount of lung tissue resected. After lung resection, the remaining part of the lung expands and compensates for the resected lobe ( 9 ). The meta-analysis showed that both FVC and FVC% were more rapidly improved in the segmentectomy group, indicating that segmentectomy has an advantage in the preservation of lung volume. FEV1/FVC is an essential parameter to phenotype the functional pattern of patients if obstructive, restrictive or normal ( 10 ). There were only 2 studies reporting changes in FEV1/FVC. The meta-analysis showed that the ΔFEV1/FVC was lower in the segmentectomy group. DLCO reflects the capillary surface area available for gas diffusion. Preoperative DLCO has been demonstrated to predict the risk of complications, short- and long-term outcomes and the length of hospitalization in patients undergoing thoracic surgery ( 11 ). The meta-analysis showed a lower degree of DLCO decrease in the segmentectomy group, indicating that it had better preservation of oxygenation. Pulmonary function after lung resection can be affected by a number of factors. The number of resected segments is an important factor. Several studies observed a positive relationship between the number of resected segments and the loss of pulmonary function ( 12 – 14 ). As each lobe consisted of different numbers of segments, the improvement of pulmonary function was also determined by the resected lobe. Therefore, Macke et al. classified patients into the following two groups: those who had 1–2 segments resected and those who had 3–5 segments resected ( 14 ). This classification could reduce the influence of different lobes and could be adopted in future studies. Furthermore, anatomical excursion of the remaining lobe could also influence the preservation rate of the residual lobe. As mentioned above, right upper lobectomy can cause a reduction in the volume of the right middle lobe ( 15 ). Tane et al. found that residual lobe function was the most preserved after S6 segmentectomy, suggesting that the shape of the preserved segments (basal segment) may be amenable to inflation without anatomic displacement ( 3 ). Emphysema could also affect postoperative pulmonary function. Kashiwabara et al. reported that there were some patients with emphysema receiving lobectomy who had a greater advantage in postoperative pulmonary functions than segmentectomy ( 16 ). It was speculated that the removal of an emphysematous parenchyma may have caused a partial improvement of the regional lung volume distribution and ventilation inhomogeneity, thus causing 'compensatory lung growth'. However, the selected studies rarely described whether they included patients with emphysema or chronic obstructive pulmonary disease (COPD), which might result in increased heterogeneity. The influence of the surgical approach on pulmonary function is controversial. Some researchers reported that no differences were found between VATS surgery and open surgery ( 19 , 20 ). In contrast, some studies showed low functional loss after VATS segmentectomy, indicating that the functional benefit of segmentectomy may add to that of VATS ( 21 – 23 ). The selected studies in this meta-analysis contained both VATS and open approaches. Subgroup analysis failed due to the high heterogeneity. More data are needed to achieve a convincing conclusion. The influence of follow-up time on the recovery of pulmonary function was small. Koike et al. showed that postoperative VC and FEV1 gradually increased within 3 months of surgery and remained stable thereafter ( 17 ). Similarly, Kobayashi et al. found that the VC% and FEV1% remained almost the same 1 year after surgery ( 18 ). It was suggested that the decreases in VC and FEV1 are caused by ageing and are not affected by the operation ( 18 ). Our study has several limitations. The lack of prospective studies influences the data quality. In addition, several factors (e.g., smoking status, complications, surgical procedure, pathological type, adjuvant therapy, and patient effort in pulmonary function tests) that may influence pulmonary function were not included in the selected studies, adding to the heterogeneity. Third, only English literature was included in our study. We also found several articles written in Japanese, Turkish or Chinese when searching for studies. This meta-analysis may be more broadly representative if we include studies in all languages. Conclusion This meta-analysis suggests that segmentectomy preserves more lung function than lobectomy. There were significantly smaller decreases in FEV1, FVC, FVC%, FEV1/FVC and DLCO in the segmentectomy group than in the lobectomy group. Therefore, segmentectomy can be regarded as an alternative therapy for NSCLC. Declarations Ethics approval and consent to participate This article does not contain any studies with human participants or animals performed by any of the authors. Consent for publication Not applicable. Availability of data and materials The data are available on request. Competing interests The authors declare that they have no competing interests. Funding This study is not supported by any fundings. Relevant acknowledgments We thank all the staff members, statistical analysts, and quality control members who participated in the study. Author contributions Yuan Xu and Yingzhi Qin conducted the literature review and data collection. Dongjie Ma performed the data analysis. Yuan Xu and Hongsheng Liu wrote the manuscript. All authors read and approved the final manuscript. Disclosure of conflicts of interest All the authors confirm that there are no conflicts of interest. References Helminen O, Valo J, Andersen H, Lautam盲ki A, R盲s盲nen J, Sihvo E. Thoracoscopic segmentectomy with simple routine bronchoscopic inflation for intersegmental plane identification: short and midterm outcomes compared with lobectomy. J THORAC DIS. 2020;12(6):3073-84. Migliore M, Fornito M, Palazzolo M, Criscione A, Gangemi M, Borrata F, et al. Ground glass opacities management in the lung cancer screening era. Ann Transl Med. 2018 2018-03-01;6(5):90. Tane S, Nishio W, Nishioka Y, Tanaka H, Ogawa H, Kitamura Y, et al. Evaluation of the Residual Lung Function After Thoracoscopic Segmentectomy Compared With Lobectomy. ANN THORAC SURG. 2019 1990-11-01;108(5):1543-50. Keenan RJ, Landreneau RJ, Jr. Maley RH, Singh D, Macherey R, Bartley S, et al. Segmental resection spares pulmonary function in patients with stage I lung cancer. ANN THORAC SURG. 2004 1990-07-01;78(1):228-33, 228-33. BTS guidelines: guidelines on the selection of patients with lung cancer for surgery. THORAX. 2001 2001-02-01;56(2):89-108. Ueda K, Tanaka T, Hayashi M, Li TS, Kaneoka T, Tanaka N, et al. Compensation of pulmonary function after upper lobectomy versus lower lobectomy. J Thorac Cardiovasc Surg. 2011 2011-10-01;142(4):762-7. Nomori H, Shiraishi A, Cong Y, Sugimura H, Mishima S. Differences in postoperative changes in pulmonary functions following segmentectomy compared with lobectomy. Eur J Cardiothorac Surg. 2018 1990-03-01;53(3):640-7. Seok Y, Cho S, Lee JY, Yang HC, Kim K, Jheon S. The effect of postoperative change in bronchial angle on postoperative pulmonary function after upper lobectomy in lung cancer patients. Interact Cardiovasc Thorac Surg. 2014 2014-02-01;18(2):183-8. Sengul AT, Sahin B, Celenk C, Basoglu A. Postoperative lung volume change depending on the resected lobe. Thorac Cardiovasc Surg. 2013 2013-03-01;61(2):131-7. Santus P, Franceschi E, Radovanovic D. Sublobar resection: functional evaluation and pathophysiological considerations. J THORAC DIS. 2020 2020-06-01;12(6):3363-8. Almquist D, Khanal N, Smith L, Ganti AK. Preoperative Pulmonary Function Tests (PFTs) and Outcomes from Resected Early Stage Non-small Cell Lung Cancer (NSCLC). ANTICANCER RES. 2018 2018-05-01;38(5):2903-7. Nomori H, Shiraishi A, Cong Y, Sugimura H, Mishima S. Differences in postoperative changes in pulmonary functions following segmentectomy compared with lobectomy. Eur J Cardiothorac Surg. 2018 2018-03-01;53(3):640-7. Harada H, Okada M, Sakamoto T, Matsuoka H, Tsubota N. Functional advantage after radical segmentectomy versus lobectomy for lung cancer. ANN THORAC SURG. 2005 2005-12-01;80(6):2041-5. Macke RA, Schuchert MJ, Odell DD, Wilson DO, Luketich JD, Landreneau RJ. Parenchymal preserving anatomic resections result in less pulmonary function loss in patients with Stage I non-small cell lung cancer. J CARDIOTHORAC SURG. 2015 1990-04-01;10:49. Yoshimoto K, Nomori H, Mori T, Ohba Y, Shiraishi K, Tashiro K, et al. Postoperative change in pulmonary function of the ipsilateral preserved lung after segmentectomy versus lobectomy. Eur J Cardiothorac Surg. 2010 1990-01-01;37(1):36-9. Kashiwabara K, Sasaki J, Mori T, Nomori H, Fujii K, Kohrogi H. Relationship between functional preservation after segmentectomy and volume-reduction effects after lobectomy in stage I non-small cell lung cancer patients with emphysema. J THORAC ONCOL. 2009 1990-09-01;4(9):1111-6. Nakata M, Saeki H, Yokoyama N, Kurita A, Takiyama W, Takashima S. Pulmonary function after lobectomy: video-assisted thoracic surgery versus thoracotomy. ANN THORAC SURG. 2000 2000-09-01;70(3):938-41. Giudicelli R, Thomas P, Lonjon T, Ragni J, Morati N, Ottomani R, et al. Video-assisted minithoracotomy versus muscle-sparing thoracotomy for performing lobectomy. ANN THORAC SURG. 1994 1994-09-01;58(3):712-7, 717-8. Hwang Y, Kang CH, Kim HS, Jeon JH, Park IK, Kim YT. Comparison of thoracoscopic segmentectomy and thoracoscopic lobectomy on the patients with non-small cell lung cancer: a propensity score matching study. Eur J Cardiothorac Surg. 2015 2015-08-01;48(2):273-8. Kim SJ, Lee YJ, Park JS, Cho YJ, Cho S, Yoon HI, et al. Changes in pulmonary function in lung cancer patients after video-assisted thoracic surgery. ANN THORAC SURG. 2015 1990-01-01;99(1):210-7. Watanabe A, Ohori S, Nakashima S, Mawatari T, Inoue N, Kurimoto Y, et al. Feasibility of video-assisted thoracoscopic surgery segmentectomy for selected peripheral lung carcinomas. Eur J Cardiothorac Surg. 2009 2009-05-01;35(5):775-80, 780. Zhong N, Mi Y, Huang B, Chen G, Yu G. Comparison of efficacy between thoracoscopic anatomic segmentectomy and thoracoscopic lobectomy in treating early-stage non-small cell lung cancer. Journal of B.U.ON. 2020;25(1):255-61. Takizawa T, Haga M, Yagi N, Terashima M, Uehara H, Yokoyama A, et al. Pulmonary function after segmentectomy for small peripheral carcinoma of the lung. J Thorac Cardiovasc Surg. 1999 1990-09-01;118(3):536-41. Gu Z, Wang H, Mao T, Ji C, Xiang Y, Zhu Y, et al. Pulmonary function changes after different extent of pulmonary resection under video-assisted thoracic surgery. J THORAC DIS. 2018 1990-04-01;10(4):2331-7. Kobayashi N, Kobayashi K, Kikuchi S, Goto Y, Ichimura H, Endo K, et al. Long-term pulmonary function after surgery for lung cancer. Interact Cardiovasc Thorac Surg. 2017 1990-05-01;24(5):727-32. Saito H, Nakagawa T, Ito M, Imai K, Ono T, Minamiya Y. Pulmonary function after lobectomy versus segmentectomy in patients with stage I non-small cell lung cancer. WORLD J SURG. 2014 1990-08-01;38(8):2025-31. Yoshimoto K, Nomori H, Mori T, Ohba Y, Shibata H, Tashiro K, et al. A segmentectomy of the right upper lobe has an advantage over a right upper lobectomy regarding the preservation of the functional volume of the right middle lobe: analysis by perfusion single-photon emission computed tomography/computed tomography. SURG TODAY. 2010 2010-07-01;40(7):614-9. Supplementary Files FigureS1.png Figure S1. Weighted ΔFEV1 between the segmentectomy group and the lobectomy group. FigureS2.png Figure S2. Weighted ΔFEV1% between the segmentectomy group and the lobectomy group. FigureS3.png Figure S3. Weighted ΔFVC% between the segmentectomy group and the lobectomy group. FigureS4.png Figure S4. Weighted ΔDLCO% between the segmentectomy group and the lobectomy group. FigureS5.png Figure S5. Weighted ΔMVV% between the segmentectomy group and the lobectomy group. Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Major revision 15 Mar, 2022 Reviews received at journal 14 Mar, 2022 Reviewers invited by journal 13 Mar, 2022 Editor assigned by journal 05 Nov, 2021 Submission checks completed at journal 04 Nov, 2021 Editor invited by journal 04 Nov, 2021 First submitted to journal 03 Nov, 2021 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-1048811","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research article","associatedPublications":[],"authors":[{"id":63337331,"identity":"bf24b0a3-046b-459d-bc2c-5e0a2aa7f556","order_by":0,"name":"Yuan Xu","email":"","orcid":"","institution":"Peking Union Medical College Hospital","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Yuan","middleName":"","lastName":"Xu","suffix":""},{"id":63337332,"identity":"b0d877bc-ebc0-4bba-843b-5e979037a480","order_by":1,"name":"Yingzhi Qin","email":"","orcid":"","institution":"Peking Union Medical College Hospital","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Yingzhi","middleName":"","lastName":"Qin","suffix":""},{"id":63337333,"identity":"28ec0368-6a2b-4737-b457-a98f68843afe","order_by":2,"name":"Dongjie Ma","email":"","orcid":"","institution":"Peking Union Medical College Hospital","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Dongjie","middleName":"","lastName":"Ma","suffix":""},{"id":63337334,"identity":"e8a4c1b5-eeb1-4711-9dd1-c96e29370cc3","order_by":3,"name":"Hongsheng Liu","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA9ElEQVRIiWNgGAWjYBACAxDB2AAk2IFkQoUNDz9/A7FamIHkgzNpMpIzDhCtBUg/bDlsY9CQgF+LOXvv4Zc/d9jkyTszt0kkNpznMWA4wPjhYw5uLZY959Ksec+kFRseZgRq2XGbx5y5gVly5jY8DruRY2bM2HY4cWMzSMuZ2zyWDQfYmHkJaDH82fYfqqXtHI/BgQSCWowf8LYdSJzPDNZygAgtZ86YMfO2JSduYGZstkg4k8wjOeNgM36/HO8x/vizzS5xfnv7w5s/Kuzs+fmbD374iEcLELBJgPUegAuAowkvYP4AIuUJqhsFo2AUjIIRCwBHeFi95xYGVQAAAABJRU5ErkJggg==","orcid":"","institution":"Peking Union Medical College Hospital","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Hongsheng","middleName":"","lastName":"Liu","suffix":""}],"badges":[],"createdAt":"2021-11-04 03:42:49","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-1048811/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-1048811/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":15596725,"identity":"2436e2f7-abb9-44ea-a5e4-4ac67e1d2001","added_by":"auto","created_at":"2021-11-16 15:35:47","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":37490,"visible":true,"origin":"","legend":"A flow diagram of the study selection.","description":"","filename":"Figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-1048811/v1/2ab19da2ec9a2324772674bb.png"},{"id":15596509,"identity":"dedb55c5-ce4b-4ff5-80e3-4957cb9d9c9b","added_by":"auto","created_at":"2021-11-16 15:32:47","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":12069,"visible":true,"origin":"","legend":"Weighted ΔFEV1 between the segmentectomy group and the lobectomy group.","description":"","filename":"Figure2.png","url":"https://assets-eu.researchsquare.com/files/rs-1048811/v1/62a7c72bd0a48fadd8be3243.png"},{"id":15596516,"identity":"d662f0a8-3c28-45e5-b347-ac96c3feb734","added_by":"auto","created_at":"2021-11-16 15:32:48","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":9543,"visible":true,"origin":"","legend":"Weighted ΔFEV1% between the segmentectomy group and the lobectomy group in Stage IA patients.","description":"","filename":"Figure3.png","url":"https://assets-eu.researchsquare.com/files/rs-1048811/v1/04ff2c66ac93bb5442cbaae5.png"},{"id":15596511,"identity":"90af7344-6f06-48f2-b734-fbfa92f76fbc","added_by":"auto","created_at":"2021-11-16 15:32:48","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":9787,"visible":true,"origin":"","legend":"Weighted ΔFVC between the segmentectomy group and the lobectomy group.","description":"","filename":"Figure4.png","url":"https://assets-eu.researchsquare.com/files/rs-1048811/v1/827039c68402039fa790d743.png"},{"id":15596518,"identity":"56dbe66a-1f00-4a86-8cd2-59ff1a9471fa","added_by":"auto","created_at":"2021-11-16 15:32:48","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":9401,"visible":true,"origin":"","legend":"Weighted ΔFVC% between the segmentectomy group and the lobectomy group.","description":"","filename":"Figure5.png","url":"https://assets-eu.researchsquare.com/files/rs-1048811/v1/ac4212e80605fe771c17aa1e.png"},{"id":15596514,"identity":"37374428-bc55-45b3-8cbe-7fb253476bb0","added_by":"auto","created_at":"2021-11-16 15:32:48","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":8913,"visible":true,"origin":"","legend":"Weighted ΔFEV1/FVC between the segmentectomy group and the lobectomy group.","description":"","filename":"Figure6.png","url":"https://assets-eu.researchsquare.com/files/rs-1048811/v1/b74d1c808123a45dcd7c31dc.png"},{"id":15596517,"identity":"01ca077a-a51d-495d-8ecc-bd685114696e","added_by":"auto","created_at":"2021-11-16 15:32:48","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":9227,"visible":true,"origin":"","legend":"Weighted ΔDLCO between the segmentectomy group and the lobectomy group.","description":"","filename":"Figure7.png","url":"https://assets-eu.researchsquare.com/files/rs-1048811/v1/1ec51aaac6a9535c135565ca.png"},{"id":15596731,"identity":"36006db8-e664-43ff-82d1-ce00cd3a10ce","added_by":"auto","created_at":"2021-11-16 15:35:51","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":409971,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-1048811/v1/3edb3100-e659-46a9-a050-82867589cf51.pdf"},{"id":15596726,"identity":"19581834-8c05-4e1a-bf11-e7698ac15abd","added_by":"auto","created_at":"2021-11-16 15:35:48","extension":"png","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":13008,"visible":true,"origin":"","legend":"Figure S1. Weighted ΔFEV1 between the segmentectomy group and the lobectomy group.","description":"","filename":"FigureS1.png","url":"https://assets-eu.researchsquare.com/files/rs-1048811/v1/336f2db92d1936f1cf8237e7.png"},{"id":15596508,"identity":"244f6a0a-0c1b-4872-a7c9-8837e84638b8","added_by":"auto","created_at":"2021-11-16 15:32:47","extension":"png","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":12640,"visible":true,"origin":"","legend":"Figure S2. Weighted ΔFEV1% between the segmentectomy group and the lobectomy group.","description":"","filename":"FigureS2.png","url":"https://assets-eu.researchsquare.com/files/rs-1048811/v1/46525cd0d3705ec9d45c8a36.png"},{"id":15596513,"identity":"6e5ec9ab-fe75-44bd-a9fc-20bccf4324cb","added_by":"auto","created_at":"2021-11-16 15:32:48","extension":"png","order_by":3,"title":"","display":"","copyAsset":false,"role":"supplement","size":10661,"visible":true,"origin":"","legend":"Figure S3. Weighted ΔFVC% between the segmentectomy group and the lobectomy group.","description":"","filename":"FigureS3.png","url":"https://assets-eu.researchsquare.com/files/rs-1048811/v1/f5ffb494660a34b75531da92.png"},{"id":15596727,"identity":"b6c44011-3059-4a32-9e60-29b14154e62c","added_by":"auto","created_at":"2021-11-16 15:35:48","extension":"png","order_by":4,"title":"","display":"","copyAsset":false,"role":"supplement","size":10245,"visible":true,"origin":"","legend":"Figure S4. Weighted ΔDLCO% between the segmentectomy group and the lobectomy group.","description":"","filename":"FigureS4.png","url":"https://assets-eu.researchsquare.com/files/rs-1048811/v1/da31fe04372f17b15ff207fc.png"},{"id":15596519,"identity":"f88ad8fc-2dd5-47d4-8027-c0b8134840a9","added_by":"auto","created_at":"2021-11-16 15:32:48","extension":"png","order_by":5,"title":"","display":"","copyAsset":false,"role":"supplement","size":9505,"visible":true,"origin":"","legend":"Figure S5. Weighted ΔMVV% between the segmentectomy group and the lobectomy group.","description":"","filename":"FigureS5.png","url":"https://assets-eu.researchsquare.com/files/rs-1048811/v1/53641626a6f1f5e57fd47abb.png"}],"financialInterests":"","formattedTitle":"\u003cp\u003eThe Impact of Segmentectomy Versus Lobectomy on Pulmonary Function in Patients With Non-small-cell Lung Cancer: a Meta-analysis\u003c/p\u003e","fulltext":[{"header":"Introduction","content":"\u003cp\u003eLung cancer is one of the leading cause of cancer-related death worldwide (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e). Surgical resection for non-small-cell lung cancer (NSCLC) is the standard treatment that leads to the best chance of a cure. For the 100-year history of surgery, lobectomy has remained the gold standard for operable NSCLC. In recent years, segmentectomy has been reported as an alternative to lobectomy for small-sized NSCLC without detriment in survival (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e). Theoretically, segmentectomy has an advantage over lobectomy on anatomical functional. However, the long-term benefits of segmentectomy over lobectomy on pulmonary function have not been firmly established. Reports related to the utility of segmentectomy in preserving lung function are conflicting. The purpose of this study was to perform a meta-analysis to compare postoperative changes in pulmonary function in NSCLC patients undergoing segmentectomy or lobectomy.\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv class=\"Section2\" id=\"Sec3\"\u003e\n \u003ch2\u003eInclusion and Exclusion Criteria\u003c/h2\u003e\n \u003cp\u003eStudies were included if they met the following inclusion criteria: (\u003cspan class=\"CitationRef\"\u003e1\u003c/span\u003e) patients diagnosed with NSCLC underwent surgical treatment; (\u003cspan class=\"CitationRef\"\u003e2\u003c/span\u003e) comparative data between segmentectomy and lobectomy were available; and (\u003cspan class=\"CitationRef\"\u003e3\u003c/span\u003e) preoperative and postoperative pulmonary function data were available. The outcomes included forced expiratory volume in 1 second (FEV1), predicted FEV1 percentage (FEV1%), forced vital capacity (FVC), predicted FVC percentage (FVC%), FEV1/FVC, maximal voluntary ventilation (MVV), diffusion capacity of carbon monoxide (DLCO) and predicted DLCO percentage (DLCO%). Studies were excluded if the full text was not in English or could not be accessed.\u003c/p\u003e\n\u003c/div\u003e\n\u003ch2\u003eSearch Strategy\u003c/h2\u003e\n\u003cp\u003eMedline, Embase, Web of Science and Scopus were searched through May 2021. The following search terms and strategies were used: (\u003cspan class=\"CitationRef\"\u003e1\u003c/span\u003e) respiratory function OR pulmonary function OR FEV1 OR FVC OR MVV OR DLCO; (\u003cspan class=\"CitationRef\"\u003e2\u003c/span\u003e) lung cancer; (\u003cspan class=\"CitationRef\"\u003e3\u003c/span\u003e) lobectomy AND (segmentectomy OR sublobar resection OR limited resection), and (\u003cspan class=\"CitationRef\"\u003e1\u003c/span\u003e) AND (\u003cspan class=\"CitationRef\"\u003e2\u003c/span\u003e) AND (\u003cspan class=\"CitationRef\"\u003e3\u003c/span\u003e). Data were extracted with a standardized form. The Newcastle\u0026ndash;Ottawa Scale (NOS) was used for quality assessment.\u003c/p\u003e\n\u003cdiv class=\"Section2\" id=\"Sec5\"\u003e\n \u003ch2\u003eStatistical Analysis\u003c/h2\u003e\n \u003cp\u003eInconsistency between studies was quantified by calculating the I\u003csup\u003e2\u003c/sup\u003e statistic. Continuous variables were reported as weighted mean differences (WMDs) and 95% confidence intervals (95% CIs). A random-effects model was used for heterogeneous data (I\u003csup\u003e2\u003c/sup\u003e\u0026gt;50%), whereas a fixed-effects model was used for homogenous data (I\u003csup\u003e2\u003c/sup\u003e\u0026lt;50%). P\u0026lt;0.05 was considered to be statistically significant. SAS software, version 9.1 (SAS Institute, Cary, NC, USA) and Review Manager, version 5.4 (The Cochrane Collaboration) were used to perform statistical analysis.\u003c/p\u003e\n\u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\n\u003cp\u003e\u003cstrong\u003eSearch Results\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe initial database search identified 172 articles in Medline, 251 in Embase, 154 in Web of Science and 166 in Scopus. After excluding duplicate records, 324 studies were included. A total of 273 articles were excluded because they failed to meet the inclusion criteria after review of the abstracts and titles. An additional 37 articles were excluded after the full text review. Hence, a total of 14 studies (13 retrospective and 1 prospective observational) including 2412 patients (976 sublobar resection and 1436 lobectomy) were finally selected. The detailed selection process is shown in Figure \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\n\u003cp\u003eThe major characteristics of the participants in the included studies are shown in Table \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e. Patients in 8 studies had NSCLC with TNM stage I. Six studies included the VATS approach only, 2 included the open approach only, and 3 included both. Two studies included wedge resections. The follow-up time (from surgery to postoperative pulmonary function) ranged from 3 to 60 months.\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\n\u003ctable id=\"Tab1\" border=\"1\"\u003e\u003ccaption\u003e\n\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\n\u003cdiv class=\"CaptionContent\"\u003e\n\u003cp\u003eBasic characteristics of the included studies.\u003c/p\u003e\n\u003c/div\u003e\n\u003c/caption\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eID\u003c/p\u003e\n\u003c/th\u003e\n\u003cth rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eLocation\u003c/p\u003e\n\u003c/th\u003e\n\u003cth rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eEnrolment Year\u003c/p\u003e\n\u003c/th\u003e\n\u003cth rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eTotal No.\u003c/p\u003e\n\u003c/th\u003e\n\u003cth rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eNo. of segmentectomy\u003c/p\u003e\n\u003c/th\u003e\n\u003cth rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eTNM stage\u003c/p\u003e\n\u003c/th\u003e\n\u003cth rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eApproach\u003c/p\u003e\n\u003c/th\u003e\n\u003cth rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eWedge resection included\u003c/p\u003e\n\u003c/th\u003e\n\u003cth colspan=\"3\" align=\"left\"\u003e\n\u003cp\u003eInvolved lobe\u003c/p\u003e\n\u003c/th\u003e\n\u003cth rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eFollow-up (month)\u003c/p\u003e\n\u003c/th\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eUpper\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eMiddle\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eLower\u003c/p\u003e\n\u003c/th\u003e\n\u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eKim 2015 (22)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eKorea\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2003-2012\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e300\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e73\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eI-IV\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eVATS\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eyes\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd colspan=\"3\" align=\"left\"\u003e\n\u003cp\u003eNM\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3\u0026amp;12\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eZhong 2020 (24)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eChina\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e2014-2016\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e144\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e68\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eIA-IB\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eVATS\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eno\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e35\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e9\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e24\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e6\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e37\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e11\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e28\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eNomori 2018c\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eJapan\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e2013-2016\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e206\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e103\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eNM\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eVATS+open\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eno\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e57\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e46\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e6\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e57\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e46\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eTakizawa 1999 (25)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eJapan\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e1993-1996\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e80\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e40\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eIA\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eopen\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eno\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e25\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e15\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e12\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e28\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e12\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eTane 2019 (3)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eJapan\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e2012-2017\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e148\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e74\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eIA1-IA2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eVATS\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eno\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e45\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e29\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e6\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e45\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e29\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eHelminen 2020 (1)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eJapan\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2007-2019\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e215\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e105\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eI-III\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eVATS\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eno\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd colspan=\"3\" align=\"left\"\u003e\n\u003cp\u003eNM\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eNM\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eGu 2018 (26)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eChina\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e2011-2014\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e109\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e34\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eIA\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eVATS\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eyes\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e23\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e11\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e6\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e50\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e25\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eKobayashi 2017 (18)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eJapan\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2001-2009\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e346\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e118\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eI-III\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eVATS+open\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eno\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd colspan=\"3\" align=\"left\"\u003e\n\u003cp\u003eNM\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e12 \u0026amp; 60\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eKeenan 2004 (4)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eUSA\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e1996-2001\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e201\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e54\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eIA\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eNM\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eno\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e23\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e31\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e12\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e87\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e17\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e43\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eKashiwabara 2009 (16)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eJapan\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e2000-2006\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e118\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e71\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eI\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eNM\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eno\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e38\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e33\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e6\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e32\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e15\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eMacke 2015 (14)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eUSA\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e1996-2001\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e159\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e77\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eI\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eVATS+open\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eno\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e36\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e9\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e32\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e6-36\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e48\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e34\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eSaito 2014 (27)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eJapan\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e2006-2012\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e178\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e52\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eI\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eopen\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eno\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e30\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e22\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e6\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e71\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e6\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e49\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eYoshimoto 2010 (28)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eJapan\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e2005-2008\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e20\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e13\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eNM\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eNM\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eno\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e13\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e5\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eHwang 2015 (21)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eKorea\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2005-2013\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e188\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e94\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eI-IV\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eVATS\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eno\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd colspan=\"3\" align=\"left\"\u003e\n\u003cp\u003eNM\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eNM\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003ctfoot\u003e\n\u003ctr\u003e\n\u003ctd colspan=\"12\"\u003eNM, not mentioned; VATS, video-assisted thoracoscopic surgery.\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tfoot\u003e\n\u003c/table\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eQuality Assessment\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe quality of the included studies was assessed using the NOS (\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e\u003ca href=\"http://www.ohri.ca/programs/clinical_epidemiology/oxford.htm\" target=\"_blank\"\u003ewww.ohri.ca/programs/clinical_epidemiology/oxford.htm\u003c/a\u003e\u003c/span\u003e\u003c/span\u003e). Two independent reviewers conducted the assessment. Disagreements were resolved by discussion. Of the studies, seven scored 9 points, four scored 8 points, two scored 7 points, and one scored 6 points, indicating that all the studies had relatively high quality (Table \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\n\u003ctable id=\"Tab2\" border=\"1\"\u003e\u003ccaption\u003e\n\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\n\u003cdiv class=\"CaptionContent\"\u003e\n\u003cp\u003eQuality assessment according to the Newcastle\u0026ndash;Ottawa scale.\u003c/p\u003e\n\u003c/div\u003e\n\u003c/caption\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eID\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eSelection\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eComparability\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eExposure\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eTotal score\u003c/p\u003e\n\u003c/th\u003e\n\u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eKim 2015 (22)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e8\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eZhong 2020 (24)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e4\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e8\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eNomori 2018 (7)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e4\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e9\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eTakizawa 1999 (25)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e4\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e9\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eTane 2019 (3)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e4\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e9\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eHelminen 2020 (1)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e7\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eGu 2018 (26)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e4\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e9\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eKobayashi 2017 (18)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e4\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e9\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eKeenan 2004 (4)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e6\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eKashiwabara 2009 (16)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e4\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e9\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eMacke 2015 (14)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e4\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e9\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eSaito 2014 (27)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e4\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e8\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eYoshimoto 2010 (28)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e7\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eHwang 2015 (21)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e4\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e8\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical Outcomes\u003c/strong\u003e\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec10\" class=\"Section2\"\u003e\n\u003cp\u003e\u003cstrong\u003eFEV1 \u0026amp; FEV1%\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFEV1 was the most frequently reported functional value. It was recorded in 10 studies (n = 1664, I\u003csup\u003e2\u003c/sup\u003e = 95%, random-effects model, Figure S1). The mean \u0026Delta;FEV1 varied from \u0026minus;0.10 to -0.44 (segmentectomy group) and -0.23 to -0.50 (lobectomy group). After ruling out one study with high heterogeneity (\u003cspan class=\"CitationRef\"\u003e3\u003c/span\u003e), the \u0026Delta;FEV1 was significantly lower in the segmentectomy group than in the lobectomy group [P\u0026lt;0.01, WMD = 0.40 (0.29, 0.51); heterogeneity: Chi\u003csup\u003e2\u003c/sup\u003e = 7.45, df = 8, P = 0.49; I\u003csup\u003e2\u003c/sup\u003e = 0%, fixed-effects model; Figure \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e].\u003c/p\u003e\n\u003cp\u003eThe FEV1% was incomparable due to the high heterogeneity (8 studies, n=1633, I\u003csup\u003e2\u003c/sup\u003e = 96%, random-effects model, Figure S2). The mean \u0026Delta;FEV1% varied from -9.2% to +1.0% (segmentectomy group) and -16.2% to -8.1% (lobectomy group). Subgroup analysis showed that in stage IA patients, the \u0026Delta;FEV1% was significantly lower in the segmentectomy group [3 studies, n=427; P\u0026lt;0.01, WMD = 0.26 (0.07, 0.46); heterogeneity: Chi\u003csup\u003e2\u003c/sup\u003e = 2.13, df = 2, P = 0.35; I\u003csup\u003e2\u003c/sup\u003e = 6%, fixed-effects model; Figure \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e].\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\n\u003cp\u003e\u003cstrong\u003eFVC \u0026amp; FVC%\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFour studies (n = 607) provided FVC values. The mean \u0026Delta;FVC varied from \u0026minus;0.07 to -0.46 (segmentectomy group) and -0.23 to -0.6 (lobectomy group). The \u0026Delta;FVC was significantly lower in the segmentectomy group than in the lobectomy group [P\u0026lt;0.01, WMD = 0.16 (0.07, 0.24); heterogeneity: Chi\u003csup\u003e2\u003c/sup\u003e = 0.38, df = 3, P = 0.94; I\u003csup\u003e2\u003c/sup\u003e = 0%, fixed-effects model; Figure \u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e\n\u003cp\u003eThe FVC% was reported in 4 studies (n = 725, I2\u0026thinsp;=\u0026thinsp;79%, random-effects model, Figure S3). After ruling out one study with high heterogeneity (\u003cspan class=\"CitationRef\"\u003e4\u003c/span\u003e), the \u0026Delta;FVC% was significantly lower in the segmentectomy group than in the lobectomy group [P\u0026lt;0.01, WMD = 4.05 (2.32, 5.79); heterogeneity: Chi\u003csup\u003e2\u003c/sup\u003e = 0.70, df = 2, P = 0.71; I\u003csup\u003e2\u003c/sup\u003e = 0%, fixed-effects model; Figure \u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e]. The \u0026Delta;FVC% varied from -1.5% to -10.5% in the segmentectomy group and -4.4% to -13.7% in the lobectomy group.\u003c/p\u003e\n\u003c/div\u003e\n\u003cp\u003e\u003cstrong\u003eOther outcomes\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe \u0026Delta;FEV1/FVC was significantly lower in the segmentectomy group than in the lobectomy group [2 studies, n=646; P\u0026lt;0.01, WMD = 1.99 (0.90, 3.08); heterogeneity: Chi\u003csup\u003e2\u003c/sup\u003e = 0.48, df = 1, P = 0.49; I\u003csup\u003e2\u003c/sup\u003e = 0%, fixed-effects model; Figure \u003cspan class=\"InternalRef\"\u003e6\u003c/span\u003e]. The \u0026Delta;FEV1/FVC varied from -0.3 to -1.9 in the segmentectomy group and -1.8 to -4.2 in the lobectomy group.\u003c/p\u003e\n\u003cp\u003eSimilarly, the \u0026Delta;DLCO was significantly lower in the segmentectomy group [3 studies, P\u0026lt;0.01, WMD = 1.30 (0.69, 1.90); heterogeneity: Chi\u003csup\u003e2\u003c/sup\u003e = 2.92, df = 2, P = 0.23; I\u003csup\u003e2\u003c/sup\u003e = 31%, fixed-effects model; Figure \u003cspan class=\"InternalRef\"\u003e7\u003c/span\u003e]. The \u0026Delta;DLCO varied from -0.07 to -2.6 in the segmentectomy group and -1.8 to -3 in the lobectomy group.\u003c/p\u003e\n\u003cp\u003eThe \u0026Delta;DLCO% (n = 660, I\u003csup\u003e2\u003c/sup\u003e = 96%, random-effects model, Figure S4) and \u0026Delta;MVV% (n = 345, I\u003csup\u003e2\u003c/sup\u003e = 96%, random-effects model, Figure S5) were incomparable.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003ePrevious studies suggested that segmentectomy confers little functional advantage over lobectomy (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). It was concluded that lobectomy should remain the procedure of choice despite the slight functional advantage of limited resection. In the present study, we compared postoperative changes in pulmonary function in patients undergoing segmentectomy or lobectomy. This meta-analysis showed that there were significantly fewer decreases in FEV1, FVC, FVC%, FEV1/FVC and DLCO in the segmentectomy group than in the lobectomy group. Subgroup analysis also showed that the decrease in FEV1% was significantly less in the segmentectomy group in stage IA patients. Altogether, these studies support the assumption that segmentectomy preserves more lung function than lobectomy.\u003c/p\u003e \u003cp\u003ePulmonary function tests are recommended in all patients who undergo thoracic surgery (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e). Theoretically, segmentectomy has an anatomical functional advantage over lobectomy. First, as the adult lung cannot regenerate new alveolar septal tissues, postoperative pulmonary function is mainly determined by the amount of lung resected. Second, anatomical excursion of the nonoperated lobe after lobectomy occurred. For example, a right upper lobectomy will damage the function of the middle lobe due to the kink of the middle lobar bronchus and pulmonary artery (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). Third, compensatory lung growth could already have occurred in the ipsilateral nonoperated lobe in the lobectomy group before the operation due to the decreased function in the operated lobe, resulting in less space for postoperative lung growth (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eFEV1 is an indicator of airway resistance. Changes in FEV1 are largely related to ventilation mechanisms, including existing airway obstruction, compensatory expansion of the residual lung, and chest wall activity (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e). Lung resection will inevitably lead to displacement of the remaining lobe. The meta-analysis showed that the decrease in FEV1 was higher in the lobectomy group, indicating that lobectomy is more likely to increase airway resistance. Changes in the FVC are mainly determined by the amount of lung tissue resected. After lung resection, the remaining part of the lung expands and compensates for the resected lobe (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e). The meta-analysis showed that both FVC and FVC% were more rapidly improved in the segmentectomy group, indicating that segmentectomy has an advantage in the preservation of lung volume. FEV1/FVC is an essential parameter to phenotype the functional pattern of patients if obstructive, restrictive or normal (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e). There were only 2 studies reporting changes in FEV1/FVC. The meta-analysis showed that the ΔFEV1/FVC was lower in the segmentectomy group. DLCO reflects the capillary surface area available for gas diffusion. Preoperative DLCO has been demonstrated to predict the risk of complications, short- and long-term outcomes and the length of hospitalization in patients undergoing thoracic surgery (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e). The meta-analysis showed a lower degree of DLCO decrease in the segmentectomy group, indicating that it had better preservation of oxygenation.\u003c/p\u003e \u003cp\u003ePulmonary function after lung resection can be affected by a number of factors. The number of resected segments is an important factor. Several studies observed a positive relationship between the number of resected segments and the loss of pulmonary function (\u003cspan additionalcitationids=\"CR13\" citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e). As each lobe consisted of different numbers of segments, the improvement of pulmonary function was also determined by the resected lobe. Therefore, Macke et al. classified patients into the following two groups: those who had 1\u0026ndash;2 segments resected and those who had 3\u0026ndash;5 segments resected (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e). This classification could reduce the influence of different lobes and could be adopted in future studies. Furthermore, anatomical excursion of the remaining lobe could also influence the preservation rate of the residual lobe. As mentioned above, right upper lobectomy can cause a reduction in the volume of the right middle lobe (\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e). Tane et al. found that residual lobe function was the most preserved after S6 segmentectomy, suggesting that the shape of the preserved segments (basal segment) may be amenable to inflation without anatomic displacement (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eEmphysema could also affect postoperative pulmonary function. Kashiwabara et al. reported that there were some patients with emphysema receiving lobectomy who had a greater advantage in postoperative pulmonary functions than segmentectomy (\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e). It was speculated that the removal of an emphysematous parenchyma may have caused a partial improvement of the regional lung volume distribution and ventilation inhomogeneity, thus causing 'compensatory lung growth'. However, the selected studies rarely described whether they included patients with emphysema or chronic obstructive pulmonary disease (COPD), which might result in increased heterogeneity.\u003c/p\u003e \u003cp\u003eThe influence of the surgical approach on pulmonary function is controversial. Some researchers reported that no differences were found between VATS surgery and open surgery (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e). In contrast, some studies showed low functional loss after VATS segmentectomy, indicating that the functional benefit of segmentectomy may add to that of VATS (\u003cspan additionalcitationids=\"CR22\" citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e). The selected studies in this meta-analysis contained both VATS and open approaches. Subgroup analysis failed due to the high heterogeneity. More data are needed to achieve a convincing conclusion.\u003c/p\u003e \u003cp\u003eThe influence of follow-up time on the recovery of pulmonary function was small. Koike et al. showed that postoperative VC and FEV1 gradually increased within 3 months of surgery and remained stable thereafter (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e). Similarly, Kobayashi et al. found that the VC% and FEV1% remained almost the same 1 year after surgery (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e). It was suggested that the decreases in VC and FEV1 are caused by ageing and are not affected by the operation (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eOur study has several limitations. The lack of prospective studies influences the data quality. In addition, several factors (e.g., smoking status, complications, surgical procedure, pathological type, adjuvant therapy, and patient effort in pulmonary function tests) that may influence pulmonary function were not included in the selected studies, adding to the heterogeneity. Third, only English literature was included in our study. We also found several articles written in Japanese, Turkish or Chinese when searching for studies. This meta-analysis may be more broadly representative if we include studies in all languages.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThis meta-analysis suggests that segmentectomy preserves more lung function than lobectomy. There were significantly smaller decreases in FEV1, FVC, FVC%, FEV1/FVC and DLCO in the segmentectomy group than in the lobectomy group. Therefore, segmentectomy can be regarded as an alternative therapy for NSCLC.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis article does not contain any studies with human participants or animals performed by any of the authors.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe data are available on request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study is not supported by any fundings.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eRelevant acknowledgments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe thank all the staff members, statistical analysts, and quality control members who participated in the study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eYuan Xu and Yingzhi Qin conducted the literature review and data collection. Dongjie Ma performed the data analysis. Yuan Xu and Hongsheng Liu wrote the manuscript. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDisclosure of conflicts of interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll the authors confirm that there are no conflicts of interest.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eHelminen O, Valo J, Andersen H, Lautam盲ki A, R盲s盲nen J, Sihvo E. Thoracoscopic segmentectomy with simple routine bronchoscopic inflation for intersegmental plane identification: short and midterm outcomes compared with lobectomy. J THORAC DIS. 2020;12(6):3073-84.\u003c/li\u003e\n \u003cli\u003eMigliore M, Fornito M, Palazzolo M, Criscione A, Gangemi M, Borrata F, et al. Ground glass opacities management in the lung cancer screening era. Ann Transl Med. 2018 2018-03-01;6(5):90.\u003c/li\u003e\n \u003cli\u003eTane S, Nishio W, Nishioka Y, Tanaka H, Ogawa H, Kitamura Y, et al. Evaluation of the Residual Lung Function After Thoracoscopic Segmentectomy Compared With Lobectomy. ANN THORAC SURG. 2019 1990-11-01;108(5):1543-50.\u003c/li\u003e\n \u003cli\u003eKeenan RJ, Landreneau RJ, Jr. Maley RH, Singh D, Macherey R, Bartley S, et al. Segmental resection spares pulmonary function in patients with stage I lung cancer. ANN THORAC SURG. 2004 1990-07-01;78(1):228-33, 228-33.\u003c/li\u003e\n \u003cli\u003eBTS guidelines: guidelines on the selection of patients with lung cancer for surgery. THORAX. 2001 2001-02-01;56(2):89-108.\u003c/li\u003e\n \u003cli\u003eUeda K, Tanaka T, Hayashi M, Li TS, Kaneoka T, Tanaka N, et al. Compensation of pulmonary function after upper lobectomy versus lower lobectomy. J Thorac Cardiovasc Surg. 2011 2011-10-01;142(4):762-7.\u003c/li\u003e\n \u003cli\u003eNomori H, Shiraishi A, Cong Y, Sugimura H, Mishima S. Differences in postoperative changes in pulmonary functions following segmentectomy compared with lobectomy. Eur J Cardiothorac Surg. 2018 1990-03-01;53(3):640-7.\u003c/li\u003e\n \u003cli\u003eSeok Y, Cho S, Lee JY, Yang HC, Kim K, Jheon S. The effect of postoperative change in bronchial angle on postoperative pulmonary \u0026nbsp;function after upper lobectomy in lung cancer patients. Interact Cardiovasc Thorac Surg. 2014 2014-02-01;18(2):183-8.\u003c/li\u003e\n \u003cli\u003eSengul AT, Sahin B, Celenk C, Basoglu A. Postoperative lung volume change depending on the resected lobe. Thorac Cardiovasc Surg. 2013 2013-03-01;61(2):131-7.\u003c/li\u003e\n \u003cli\u003eSantus P, Franceschi E, Radovanovic D. Sublobar resection: functional evaluation and pathophysiological considerations. J THORAC DIS. 2020 2020-06-01;12(6):3363-8.\u003c/li\u003e\n \u003cli\u003eAlmquist D, Khanal N, Smith L, Ganti AK. Preoperative Pulmonary Function Tests (PFTs) and Outcomes from Resected Early Stage Non-small Cell Lung Cancer (NSCLC). ANTICANCER RES. 2018 2018-05-01;38(5):2903-7.\u003c/li\u003e\n \u003cli\u003eNomori H, Shiraishi A, Cong Y, Sugimura H, Mishima S. Differences in postoperative changes in pulmonary functions following segmentectomy compared with lobectomy. Eur J Cardiothorac Surg. 2018 2018-03-01;53(3):640-7.\u003c/li\u003e\n \u003cli\u003eHarada H, Okada M, Sakamoto T, Matsuoka H, Tsubota N. Functional advantage after radical segmentectomy versus lobectomy for lung cancer. ANN THORAC SURG. 2005 2005-12-01;80(6):2041-5.\u003c/li\u003e\n \u003cli\u003eMacke RA, Schuchert MJ, Odell DD, Wilson DO, Luketich JD, Landreneau RJ. Parenchymal preserving anatomic resections result in less pulmonary function loss in patients with Stage I non-small cell lung cancer. J CARDIOTHORAC SURG. 2015 1990-04-01;10:49.\u003c/li\u003e\n \u003cli\u003eYoshimoto K, Nomori H, Mori T, Ohba Y, Shiraishi K, Tashiro K, et al. Postoperative change in pulmonary function of the ipsilateral preserved lung after segmentectomy versus lobectomy. Eur J Cardiothorac Surg. 2010 1990-01-01;37(1):36-9.\u003c/li\u003e\n \u003cli\u003eKashiwabara K, Sasaki J, Mori T, Nomori H, Fujii K, Kohrogi H. Relationship between functional preservation after segmentectomy and volume-reduction effects after lobectomy in stage I non-small cell lung cancer patients with emphysema. J THORAC ONCOL. 2009 1990-09-01;4(9):1111-6.\u003c/li\u003e\n \u003cli\u003eNakata M, Saeki H, Yokoyama N, Kurita A, Takiyama W, Takashima S. Pulmonary function after lobectomy: video-assisted thoracic surgery versus thoracotomy. ANN THORAC SURG. 2000 2000-09-01;70(3):938-41.\u003c/li\u003e\n \u003cli\u003eGiudicelli R, Thomas P, Lonjon T, Ragni J, Morati N, Ottomani R, et al. Video-assisted minithoracotomy versus muscle-sparing thoracotomy for performing lobectomy. ANN THORAC SURG. 1994 1994-09-01;58(3):712-7, 717-8.\u003c/li\u003e\n \u003cli\u003eHwang Y, Kang CH, Kim HS, Jeon JH, Park IK, Kim YT. Comparison of thoracoscopic segmentectomy and thoracoscopic lobectomy on the patients with non-small cell lung cancer: a propensity score matching study. Eur J Cardiothorac Surg. 2015 2015-08-01;48(2):273-8.\u003c/li\u003e\n \u003cli\u003eKim SJ, Lee YJ, Park JS, Cho YJ, Cho S, Yoon HI, et al. Changes in pulmonary function in lung cancer patients after video-assisted thoracic surgery. ANN THORAC SURG. 2015 1990-01-01;99(1):210-7.\u003c/li\u003e\n \u003cli\u003eWatanabe A, Ohori S, Nakashima S, Mawatari T, Inoue N, Kurimoto Y, et al. Feasibility of video-assisted thoracoscopic surgery segmentectomy for selected peripheral lung carcinomas. Eur J Cardiothorac Surg. 2009 2009-05-01;35(5):775-80, 780.\u003c/li\u003e\n \u003cli\u003eZhong N, Mi Y, Huang B, Chen G, Yu G. Comparison of efficacy between thoracoscopic anatomic segmentectomy and thoracoscopic lobectomy in treating early-stage non-small cell lung cancer. Journal of B.U.ON. 2020;25(1):255-61.\u003c/li\u003e\n \u003cli\u003eTakizawa T, Haga M, Yagi N, Terashima M, Uehara H, Yokoyama A, et al. Pulmonary function after segmentectomy for small peripheral carcinoma of the lung. J Thorac Cardiovasc Surg. 1999 1990-09-01;118(3):536-41.\u003c/li\u003e\n \u003cli\u003eGu Z, Wang H, Mao T, Ji C, Xiang Y, Zhu Y, et al. Pulmonary function changes after different extent of pulmonary resection under video-assisted thoracic surgery. J THORAC DIS. 2018 1990-04-01;10(4):2331-7.\u003c/li\u003e\n \u003cli\u003eKobayashi N, Kobayashi K, Kikuchi S, Goto Y, Ichimura H, Endo K, et al. Long-term pulmonary function after surgery for lung cancer. Interact Cardiovasc Thorac Surg. 2017 1990-05-01;24(5):727-32.\u003c/li\u003e\n \u003cli\u003eSaito H, Nakagawa T, Ito M, Imai K, Ono T, Minamiya Y. Pulmonary function after lobectomy versus segmentectomy in patients with stage I non-small cell lung cancer. WORLD J SURG. 2014 1990-08-01;38(8):2025-31.\u003c/li\u003e\n \u003cli\u003eYoshimoto K, Nomori H, Mori T, Ohba Y, Shibata H, Tashiro K, et al. A segmentectomy of the right upper lobe has an advantage over a right upper lobectomy regarding the preservation of the functional volume of the right middle lobe: analysis by perfusion single-photon emission computed tomography/computed tomography. SURG TODAY. 2010 2010-07-01;40(7):614-9.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"journal-of-cardiothoracic-surgery","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"jcts","sideBox":"Learn more about [Journal of Cardiothoracic Surgery](http://cardiothoracicsurgery.biomedcentral.com)","snPcode":"13019","submissionUrl":"https://submission.nature.com/new-submission/13019/3","title":"Journal of Cardiothoracic Surgery","twitterHandle":"@BioMedCentral","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"non-small-cell lung cancer, segmentectomy, lobectomy, pulmonary function","lastPublishedDoi":"10.21203/rs.3.rs-1048811/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-1048811/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eObjective: Segmentectomy has been reported as an alternative to lobectomy for small-sized NSCLC without detriment to survival. The long-term benefits of segmentectomy over lobectomy on pulmonary function have not been firmly established. This meta-analysis aims to compare postoperative changes in pulmonary function in NSCLC patients undergoing segmentectomy or lobectomy.\u003c/p\u003e\u003cp\u003eMethods: Medline, Embase, Web of Science and Scopus were searched through March 2021. Statistical comparisons were made when appropriate.\u003c/p\u003e\u003cp\u003eResults: Fourteen studies (2412 participants) out of 324 citations were included in this study. All selected studies were high quality, as indicated by the Newcastle–Ottawa scale for assessing the risk of bias. Clinical outcomes were compared between segmentectomy and lobectomy. ΔFEV1 [10 studies, P\u0026lt;0.01, WMD = 0.40 (0.29, 0.51)], ΔFVC [4 studies, P\u0026lt;0.01, WMD = 0.16 (0.07, 0.24)], ΔFVC% [4 studies, P\u0026lt;0.01, WMD = 4.05 (2.32, 5.79)], ΔFEV1/FVC [2 studies, P\u0026lt;0.01, WMD = 1.99 (0.90, 3.08)], and ΔDLCO [3 studies, P\u0026lt;0.01, WMD = 1.30 (0.69, 1.90)] were significantly lower in the segmentectomy group than in the lobectomy group. Subgroup analysis showed that in stage IA patients, the ΔFEV1% [3 studies, P\u0026lt;0.01, WMD = 0.26 (0.07, 0.46)] was significantly lower in the segmentectomy group. The ΔDLCO% and ΔMVV% were incomparable.\u003c/p\u003e\u003cp\u003eConclusion: Segmentectomy preserves more lung function than lobectomy. There were significantly smaller decreases in FEV1, FVC, FVC%, FEV1/FVC and DLCO in the segmentectomy group than in the lobectomy group.\u003c/p\u003e","manuscriptTitle":"The Impact of Segmentectomy Versus Lobectomy on Pulmonary Function in Patients With Non-small-cell Lung Cancer: a Meta-analysis","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2021-11-16 15:32:46","doi":"10.21203/rs.3.rs-1048811/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Major revision","date":"2022-03-15T13:39:21+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2022-03-14T07:52:19+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2022-03-13T08:34:59+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2021-11-05T07:08:29+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2021-11-04T23:00:00+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2021-11-04T23:00:00+00:00","index":"","fulltext":""},{"type":"submitted","content":"Journal of Cardiothoracic Surgery","date":"2021-11-03T23:42:31+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"journal-of-cardiothoracic-surgery","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"jcts","sideBox":"Learn more about [Journal of Cardiothoracic Surgery](http://cardiothoracicsurgery.biomedcentral.com)","snPcode":"13019","submissionUrl":"https://submission.nature.com/new-submission/13019/3","title":"Journal of Cardiothoracic Surgery","twitterHandle":"@BioMedCentral","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"ce9dbb40-9520-4178-a046-42985919e1c1","owner":[],"postedDate":"November 16th, 2021","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[{"id":8549673,"name":"Cardiothoracic Surgery"}],"tags":[],"updatedAt":"2022-04-21T11:35:30+00:00","versionOfRecord":[],"versionCreatedAt":"2021-11-16 15:32:46","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-1048811","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-1048811","identity":"rs-1048811","version":["v1"]},"buildId":"7rjqhiLT3MXkJMwkYKINL","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}