Association of iliopsoas muscle cross-sectional area with postoperative complications in older lung cancer patients

Association of iliopsoas muscle cross-sectional area with postoperative complications in older lung cancer patients | 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 Association of iliopsoas muscle cross-sectional area with postoperative complications in older lung cancer patients Shoko Kubota, Joji Samejima, Yutaro Koike, Makoto Tada, Tomohiro Miyoshi, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6859480/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 11 You are reading this latest preprint version Abstract Background Sarcopenia was correlated with increased postoperative complications and poor outcomes in patients with lung cancer. The cross-sectional area of the iliopsoas muscle on computed tomography is a relevant indicator of sarcopenia. This study aimed to investigate whether the preoperative cross-sectional area of the iliopsoas muscle is associated with the incidence of postoperative complications after lobectomy. Methods This retrospective study included 584 consecutive patients aged 70 years or older who underwent curative resection for non-small cell lung cancer between 2016 and 2020. The cross-sectional area of the iliopsoas muscle was measured at the level of the third lumbar vertebra, and the cumulative area of both sides was evaluated. Univariable and multivariable analyses were performed to identify the predictors of early postoperative complications (≥ grade II by the Clavien-Dindo classification) along with the preoperative iliopsoas muscle cross-sectional area. Results The patients were divided into two groups according to the Clavien-Dindo grade: 125 patients (21%) had ≥ grade II complications, whereas 459 patients (79%) had < grade II complications. The median iliopsoas muscle area was 1009 mm2 [range, 412–2455 mm2] in patients with < grade II complications and 797 mm2 [range, 307–1755 mm2] in those with ≥ grade II complications, with significant differences (P < 0.01). The calculated cut-off value for the iliopsoas muscle cross-sectional area was 800 mm. The multivariable analysis showed that sex (P < 0.01) and an iliopsoas muscle area of < 800 mm2 (P < 0.01) were independent factors associated with postoperative complications. The most common complications were prolonged air leakage, pneumonia, atrial fibrillation, empyema, and acute exacerbation of interstitial pneumonia. Patients with an iliopsoas muscle area of < 800 mm2 had significantly more prolonged air leakage and atrial fibrillation than those with an iliopsoas muscle area of ≥ 800 mm2 (all P = 0.04). Conclusions The cross-sectional area of the iliopsoas muscle is a valuable predictor of postoperative complications after lobectomy. Notably, patients with an iliopsoas muscle cross-sectional area < 800 mm² had significantly higher risks of pulmonary fistula and atrial fibrillation. For patients with a smaller iliopsoas muscle area, limited resection should be considered and more careful perioperative management may be necessary. Sarcopenia Lung cancer Lung postoperative complications Iliopsoas muscle Figures Figure 1 Figure 2 Figure 3 Introduction Sarcopenia, a subset of cachexia, is defined as the age-related loss of skeletal muscle mass and strength 1 . Asians differ from Europeans and Americans in terms of body size, differentiation, and lifestyle, and the Asian Working Group for Sarcopenia (AWGS) has published a consensus on sarcopenia specifically for Asians 2 . The AWGS indicated that sarcopenia is diagnosed when a reduction in skeletal muscle mass accompanies muscle weakness and reduced physical function 3 . However, muscle strength and physical function, which are diagnostic criteria, cannot be measured retrospectively. Skeletal muscle mass has often been substituted by the cross-sectional area of the L3 level iliopsoas muscle 4 , but the cut-off values have not been established. The cross-sectional area of the psoas muscle on computed tomography (CT) has been identified as a relevant indicator of sarcopenia and has been used in many studies 5,6 . Sarcopenia was correlated with increased postoperative complications and poor outcomes in patients with lung cancer 6,7 . However, the association between preoperative iliopsoas muscle cross-sectional area and the development of postoperative complications after lobectomy in older patients with lung cancer has not been investigated. In this study, we investigated whether a reduced preoperative iliopsoas muscle cross-sectional area is associated with increased postoperative complications after lobectomy in older patients. Material and Methods Patients We retrospectively reviewed 741 consecutive patients aged 70 years or older with primary lung adenocarcinoma who underwent lobectomies at our hospital between January 2016 and June 2020. Patients who underwent resection of adjacent organs along with the lung (N = 59), incomplete resection (N = 41) and underwent preoperative therapy (N = 57) were excluded. Ultimately, 584 patients were included in this study. A flowchart of the patient selection process is shown in Fig. 1 . This retrospective study was approved by the Institutional Review Board (IRB approval number: 2017 − 418). Comprehensive informed consent was obtained from all the patients. Measuring the cross-sectional area of the iliopsoas muscle The cross-sectional area of the iliopsoas muscle was measured at the upper end of the L3 vertebral level using ShadeQuest/ ViewR-DG (FUJIFILM), and the sum of the left and right sides was examined (Fig. 2 ). Abdominal CT was assessed in 5 mm slices within one month before surgery. For 29 patients who did not undergo abdominal CT, PET/CT was substituted. Postoperative complications were classified as severity within 30 days postoperatively using the Clavien–Dindo classification 8 . This grade also accounted for wound infections opened at the bedside. Grade II complications were defined as those requiring pharmacological treatment with drugs other than those permitted for grade I complications. This includes the administration of blood transfusions and total parenteral nutrition. For example, grade I pulmonary leak refers to a pulmonary leak that persists for 5 days postoperatively with only drain placement using an existing drain, whereas ≥ grade II involves replacement of an existing drain, placement of a new drain, intrapleural adhesion, and treatment under general or local anesthesia. In this study, the patients were divided into two groups: those with complications below grade II and higher than grade II. To assess post-operative complications, patients underwent ECG monitoring for two days, with blood samples and chest X-rays taken on postoperative days 1, 3, and 5. Additional tests were performed as required. The patients were discharged approximately 1 week postoperatively and followed up in the outpatient clinic. Statistical analysis Fisher exact test and multivariable logistic regression analyses were performed on 15 preoperative factors, including the preoperative iliopsoas muscle cross-sectional area, to investigate the predictive factors for the development of postoperative complications of ≥ grade II by the Clavien-Dindo classification within 30 days after surgery. The association of the incidence of each complication with the cross-sectional area of the iliopsoas muscle was evaluated based on its cut-off value. P < 0.05 was considered statistically significant. All statistical analyses were performed using EZR software (Saitama Medical Center, Jichi Medical University, Saitama, Japan 9 ) for R (R Foundation for Statistical Computing, Vienna, Austria) was used. Results Patient characteristics The clinical and pathological characteristics of the 584 patients are shown in Table 1 . The patients were divided into two groups according to the Clavien-Dindo grade: 125 patients (21%) had ≥ grade II complications, whereas 459 patients (79%) had < grade II complications. Table 1 Patient characteristics Clavien-Dindo grade Grade < II Grade ≥ II P Value No of patients 459 125 Age [median, years] 75 [70–87] 75 [70–88] 0.24 Sex Female 213 99 < 0.01* Male 246 99 Smoking history Ever 282 103 < 0.01* Never 177 22 Brinkman index [median] 440 [0-4200] 900 [0-3000] < 0.01* Height [median, cm] 158.9 [134.3-188.2] 161.9 [140.3-183.6] < 0.01* Weight [median, kg] 57.0 [30.1–99.0] 58.8 [36.2–85.5] 0.12 BMI [median] 22.8 [14.7–36.5] 22.8 [14.5–31.1] 0.96 Lung function %VC [median] 104.0 [52.9-151.1] 100.0 [57.1-164.2] 0.73 FEV1.0% [median] 76.5 [41.7-133.3] 73.2 [40.3–100.0] < 0.01* cStage 0 8 1 0.13 Ⅰ 346 83 ⅠⅠ 73 27 ⅠⅠⅠⅠ 32 14 The iliopsoas muscles areal/[median, mm 2 ] 1009 [412–2455] 797 [307–1755] < 0.01* Coexisting disease (%) Hypertension 203 (44.2) 55 (44.0) 1.00 Diabetes mellitus 88 (19.2) 28 (22.4) 0.45 Emphysema 58 (12.6) 29 (23.2) 0.01* Interstitial pneumonia 22 (4.8) 15 (12.0) 0.01* Coronary heart disease 27 (5.9) 5 (4.0) 0.51 Cerebrovascular Diseases 31 (6.8) 18 (14.4) 0.01* Gastrointestinal tract disease 32 (7.0) 6 (4.8) 0.54 Renal dysfunction 11 (2.4) 2 (1.6) 0.75 BMI: body mass index VC: vital capacity FEV1.0: forced expiratory volume in 1 second The two groups showed significant differences in sex, smoking history, brinkman index, height, FEV1.0% (all P < 0.01), and comorbidities (COPD, IP, and cerebrovascular diseases; all P = 0.01). The median iliopsoas muscle area was 1009 mm 2 [range, 412–2455 mm 2 ] in patients with < grade II complications and 797 mm 2 [range, 307–1755 mm 2 ] in those with ≥ grade II complications, with significant differences (P < 0.01). Cut-off value for iliopsoas muscle area to predict complications Receiver operating characteristic (ROC) curves were generated to predict complications and cut-off values for the iliopsoas muscle region were determined. The area under the ROC curve was 0.64 (95% CI: 0.59–0.70, Fig. 3 A). The cut-off value was set at the point of maximum Youden's index, and when the iliopsoas muscle area was 813 mm2, the sensitivity and specificity were 70.2% and 52.8%, respectively. The specificity and sensitivity were 70.2% and 52.8%, respectively. However, for clarity in clinical use, the cut-off value was set at 800 mm 2 , in which case the specificity and sensitivity were 71.0% and 51.2%, respectively (Fig. 3 B). Univariable and multivariable analyses for postoperative complications of ≥ grade 2 by the Clavien–Dindo grading system Table 2 shows the results of the univariable and multivariable analyses of postoperative complications. In the univariable analysis, age (P < 0.01), brinkman index (P < 0.01), FEV 1.0% (P < 0.01), and iliopsoas muscle area of < 800 mm 2 (P < 0.01) were prognostic factors for postoperative complications of ≥ grade II by the Clavien-Dindo classification. The multivariable analysis showed that sex (P < 0.01) and an iliopsoas muscle area of < 800 mm 2 (P < 0.01) were independent factors associated with postoperative complications. Table 2 Univariable and multivariable analysis of postoperative complications of Clavien- Dindo grade II or higher Univariable analysis Multivariable analysis Odd (95%CI) P Value Odd (95%CI) P Value Age (years) < 75 1 0.86 1 0.54 ≧ 75 1.00 (0.65–1.44) 0.87 (0.55–1.37) Sex male 1 < 0.01* 1 < 0.01* female 0.30 (0.19–0.49) 0.09 (0.04–0.20) Brinkman index < 400 1 < 0.01* 1 0.08 ≧ 400 3.04 (1.94–4.77) 1.71 (0.92–3.16) BMI < 18.5 1 0.24 1 0.67 ≧ 18.5 1.52 (0.75–3.06) 1.20 (0.53–2.72) %VC ≧ 80% 1 0.56 1 0.71 < 80% 0.82 (0.43–1.59) 1.16 (0.41–2.46) FEV1.0% ≧ 70% 1 < 0.01* 1 0.11 < 70% 0.50 (0.33–0.77) 0.67 (0.41–1.10) Comorbidity No 1 0.21 1 0.42 Yes 1.36 (0.84–2.20) 1.26 (0.72–2.20) The iliopsoas muscles area(mm 2 ) ≧ 800 1 < 0.01* 1 < 0.01* < 800 0.39 (0.26–0.58) 0.07 (0.04–0.15) Comparison of each complication and iliopsoas muscle cross-sectional area Table 3 shows the 125 patients with complications of ≥ grade II by the Clavien-Dindo classification divided into two groups according to the iliopsoas muscle area, including complications that were duplicated in one patient. Table 3 Comparison of each postoperative complication and iliopsoas muscles cross-sectional area The iliopsoas muscles area (mm 2 ) < 800 ≧ 800 P Value No of patients 197 (%) 387 (%) Prolonged air leakage 26 (13.20) * 29 (7.49) * 0.04* Pneumonia 11 (5.58) * 15 (3.88) * 0.49 Atrial fibrillation 12 (6.09) * 10 (2.58) * 0.04* Empyema 5 (2.54) * 3 (0.78) * 0.13 Acute exacerbation of interstitial pneumonia 4 (2.00) * 4 (1.03) * 0.45 Atelectasis lung 3 (1.52) * 4 (1.03) * 0.69 Delirium 3 (1.52) * 2 (0.52) 0.34 Subcutaneous emphysema 0 (0.00) 2 (0.52) * 0.55 Hypoxemia 1 (0.51) * 2 (0.52) * 1.00 Wound infection 2 (1.02) * 0 (0.00) 0.11 Gastrointestinal ulcer 2 (1.02) * 0 (0.00) 0.11 Postoperative hemorrhage 2 (1.02) 0 (0.00) 0.11 Cerebrovascular disease 2 (1.02) * 0 (0.00) 0.11 * There are some overlapping The most common complications were prolonged air leakage, pneumonia, atrial fibrillation, empyema, and acute exacerbation of interstitial pneumonia. Patients with an iliopsoas muscle area of < 800 mm 2 had significantly more prolonged air leakage and atrial fibrillation than those with an iliopsoas muscle area of ≥ 800 mm 2 (all P = 0.04). Discussion Our study examined the preoperative iliopsoas muscle cross-sectional area and postoperative complications after pulmonary lobectomy in older patients with lung cancer. A reduced preoperative iliopsoas muscle area was a risk factor for postoperative complications of Clavien-Dindo classification ≥ grade II. Pulmonary leakage and atrial fibrillation were affected by iliopsoas muscle mass. In particular, the incidence of prolonged air leakage and atrial fibrillation was significantly higher in patients with an iliopsoas muscle cross-sectional area of < 800 mm 2 . Sarcopenia is defined as a syndrome characterized by the progressive and generalized loss of skeletal muscle mass and strength, with a risk of physical disability, reduced quality of life, and death 10 . However, the criteria for Europeans are unlikely to be directly adaptable to Asians. In 2014 2 and 2020, the Asian Working Group for Sarcopenia (AWGS) defined the diagnostic criteria for Asians. Skeletal muscle areas of various muscles are used as indicators for sarcopenia, one of which is the iliopsoas muscle 6,11,12 . However, there is no fixed consensus on the evaluation methods and cut-off values, which vary from report to report. In Japan, the diagnostic criteria for sarcopenia in patients aged ≥ 65 years are used from the AWGS report 3 , but there are no reports examining the risk factors for postoperative complications and each complication in terms of iliopsoas muscle mass limited to older patients. Previous reports on the association of lung cancer 6,12 and iliopsoas muscle volume have reported iliopsoas muscle volume to be a risk factor for postoperative complications using PMI (iliopsoas muscle volume sum at the L3 level/(height) 2 ) and PVI (iliopsoas muscle cross-sectional area sum/(height) 2 ). Vocal cord paralysis and atrial fibrillation have been reported as complications associated with reduced iliopsoas muscle volume 12 . Our results are consistent with those of previous studies. These reports have only reviewed cases not related to age at surgery 6,11, 12 or investigated the incidence of complications in patients aged ≥ 65 years 13 . However, there are no reports comparing the risk factors for postoperative complications and each complication in older patients aged ≥ 70 years, as in the present study. The iliopsoas muscle area has also been reported to influence postoperative complications in other cancers 14,15 , but no reports have been limited to older patients. Our study is the first to report the association between the iliopsoas muscle area and postoperative complications in older patients among all reports, including those with lung cancer. Atrial fibrillation after thoracic surgery may have several causes; however, reports suggest that it depends on the procedure. It is 10–15% lower in case of lobectomy or greater and as high as 20–30% in case of total pneumonectomy 16 . Risk factors of atrial fibrillation include older age, male sex, and right lung surgery 17,18 . Sympathetic stimulation and atrial dilatation are considered triggering factors, but their pathogenesis is thought to be multifactorial and is not precisely understood 19,20 . The mechanism by which reduced iliopsoas muscle mass leads to the development of atrial fibrillation has not been investigated, and further studies are needed. In our study, more older patients with a low iliopsoas muscle area had pulmonary leakage, and patients with Clavien–Dindo classification ≥ grade II pulmonary leakage were more likely to be smokers and have a higher Brinkman index score and coexisting emphysema. This was attributed to a decrease in general fitness and sarcopenia, with longer exposure to smoking being associated with emphysema and respiratory function features. Risk factors for persistent postoperative pulmonary leakage include male sex, lower BMI, and operation time, in addition to factors related to surgical manipulation 21 . The development of postoperative complications may be related to various comorbidities in older patients. This study has several limitations. First, this was a retrospective study that used a single-center database. However, this is the first large analysis of 584 older patients with lung cancer. Secondly, it is unclear whether the present measurement of the iliopsoas muscle area adequately reflects sarcopenia, a systemic disease. We plan to assess sarcopenia preoperatively according to the AWGS criteria in a future prospective study. Conclusion Cross-sectional area of the iliopsoas is a predictor of postoperative complications. In particular, the incidence of pulmonary fistula (prolonged/delayed) and atrial fibrillation was significantly higher in patients with an iliopsoas cross-sectional area of < 800 mm 2 . For patients with a smaller iliopsoas muscle area, limited resection should be considered and more careful perioperative management may be necessary. Abbreviations BMI body mass index COPD chronic obstructive pulmonary disease IP Interstitial pneumonia VC vital capacity FEV1.0 forced expiratory volume in 1 second NSCLC non-small cell lung cancer Declarations Acknowledgments We thank Yasunori Kaminuma for his help in collecting the data. We would like to thank Editage (www.editage.jp) for English language editing. CRediT authorship contribution statement Shoko Kubota: Conceptualization, Methodology, Formal analysis, Investigation, Resources, Writing - original draft. Joji Samejima: Methodology, Formal analysis, Investigation, Writing – review & editing. Yutaro Koike: Writing – review & editing. Tomohiro Miyoshi: Writing – review & editing. Kenta Tane: Writing – review & editing. Masashi Wakabayashi : Methodology, Formal analysis, Writing – review & editing. Keiju Aokage: Writing – review & editing. Masahiro Tsuboi: Methodology, Formal analysis, Investigation, Writing– review & editing, Funding acquisition, Supervision Funding information: Not applicable. Availability of data and material: Not applicable. Code availability: Not applicable. Ethics approval: This retrospective study was approved by the Institutional Review Board (IRB approval number; 2017-418). Consent to participate: Informed consent was obtained from all patients. Consent for publication: Not applicable. References Rosenberg IH. 1989 Herman Award lecture. Folate absorption: clinical questions and metabolic answers. Am J Clin Nutr . 1990;51:531-534. Chen LK, Liu LK, Woo J, et al. Sarcopenia in Asia: consensus report of the Asian Working Group for Sarcopenia. J Am Med Dir Assoc . 2014;15:95-101. Chen LK, Woo J, Assantachai P, et al. Asian Working Group for Sarcopenia: 2019 Consensus Update on Sarcopenia Diagnosis and Treatment. J Am Med Dir Assoc . 2020;21:300-307 e302. Hamaguchi Y, Kaido T, Okumura S, et al. Proposal for new diagnostic criteria for low skeletal muscle mass based on computed tomography imaging in Asian adults. Nutrition . 2016;32:1200-1205. Prado CM, Lieffers JR, McCargar LJ, et al. Prevalence and clinical implications of sarcopenic obesity in patients with solid tumours of the respiratory and gastrointestinal tracts: a population-based study. 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Motono N, Mizoguchi T, Ishikawa M, Iwai S, Iijima Y, Uramoto H. Analysis of risk factors of postoperative complication for non-small cell lung cancer. BMC Pulm Med . 2024;24:333. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 08 Oct, 2025 Reviews received at journal 26 Aug, 2025 Reviews received at journal 18 Aug, 2025 Reviewers agreed at journal 16 Aug, 2025 Reviews received at journal 15 Aug, 2025 Reviewers agreed at journal 15 Aug, 2025 Reviewers agreed at journal 11 Aug, 2025 Reviewers invited by journal 11 Aug, 2025 Editor assigned by journal 11 Jun, 2025 Submission checks completed at journal 11 Jun, 2025 First submitted to journal 10 Jun, 2025 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. 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East","correspondingAuthor":false,"prefix":"","firstName":"Masahiro","middleName":"","lastName":"Tsuboi","suffix":""}],"badges":[],"createdAt":"2025-06-10 06:08:31","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6859480/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6859480/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":89394771,"identity":"7226c981-f9e4-4aff-9f4d-06e7b3b47eb5","added_by":"auto","created_at":"2025-08-19 13:36:01","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":39512,"visible":true,"origin":"","legend":"\u003cp\u003eA flowchart of the patient selection process.\u003c/p\u003e","description":"","filename":"Figure1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6859480/v1/4ddb27419af5c2b87195978a.jpg"},{"id":89394774,"identity":"3381654d-9a67-4f5f-9bff-93728462547c","added_by":"auto","created_at":"2025-08-19 13:36:01","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":116341,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eA\u003c/em\u003e\u003cstrong\u003e \u003c/strong\u003eThe left and right iliopsoas muscle on CT at the L3 level are shown.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eB\u003c/em\u003e\u003cstrong\u003e \u003c/strong\u003eThe sum of the cross-sectional areas of the iliopsoas muscle enclosed by the yellow border was calculated.\u003c/p\u003e","description":"","filename":"Figure2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6859480/v1/9d69d7bc02ec1d29a8d6f84b.jpg"},{"id":89396968,"identity":"6dcddfb5-b004-4e0f-b3c6-def52858c13e","added_by":"auto","created_at":"2025-08-19 13:44:01","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":45987,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eA\u003c/em\u003e\u003cstrong\u003e \u003c/strong\u003eROC curve for determining the cut-off value of the iliopsoas muscle area that predicts complications of Clavien–Dindo classification grade II or higher.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eB\u003c/em\u003e\u003cstrong\u003e \u003c/strong\u003eROC curve for a cutoff value of 800 mm\u003csup\u003e2\u003c/sup\u003e for the iliopsoas muscle area.\u003c/p\u003e","description":"","filename":"Figure3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6859480/v1/d3847747d2b3901cdcfe14a0.jpg"},{"id":89397993,"identity":"ce30343a-5424-4abe-8278-beb6313d2038","added_by":"auto","created_at":"2025-08-19 13:52:01","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1128000,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6859480/v1/8b44c9f6-7a75-4d2e-ad02-35744a0457d9.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Association of iliopsoas muscle cross-sectional area with postoperative complications in older lung cancer patients","fulltext":[{"header":"Introduction","content":"\u003cp\u003eSarcopenia, a subset of cachexia, is defined as the age-related loss of skeletal muscle mass and strength \u003csup\u003e1\u003c/sup\u003e. Asians differ from Europeans and Americans in terms of body size, differentiation, and lifestyle, and the Asian Working Group for Sarcopenia (AWGS) has published a consensus on sarcopenia specifically for Asians \u003csup\u003e2\u003c/sup\u003e. The AWGS indicated that sarcopenia is diagnosed when a reduction in skeletal muscle mass accompanies muscle weakness and reduced physical function \u003csup\u003e3\u003c/sup\u003e. However, muscle strength and physical function, which are diagnostic criteria, cannot be measured retrospectively. Skeletal muscle mass has often been substituted by the cross-sectional area of the L3 level iliopsoas muscle \u003csup\u003e4\u003c/sup\u003e, but the cut-off values have not been established. The cross-sectional area of the psoas muscle on computed tomography (CT) has been identified as a relevant indicator of sarcopenia and has been used in many studies \u003csup\u003e5,6\u003c/sup\u003e. Sarcopenia was correlated with increased postoperative complications and poor outcomes in patients with lung cancer \u003csup\u003e6,7\u003c/sup\u003e. However, the association between preoperative iliopsoas muscle cross-sectional area and the development of postoperative complications after lobectomy in older patients with lung cancer has not been investigated. In this study, we investigated whether a reduced preoperative iliopsoas muscle cross-sectional area is associated with increased postoperative complications after lobectomy in older patients.\u003c/p\u003e"},{"header":"Material and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003ePatients\u003c/h2\u003e\u003cp\u003eWe retrospectively reviewed 741 consecutive patients aged 70 years or older with primary lung adenocarcinoma who underwent lobectomies at our hospital between January 2016 and June 2020. Patients who underwent resection of adjacent organs along with the lung (N\u0026thinsp;=\u0026thinsp;59), incomplete resection (N\u0026thinsp;=\u0026thinsp;41) and underwent preoperative therapy (N\u0026thinsp;=\u0026thinsp;57) were excluded. Ultimately, 584 patients were included in this study. A flowchart of the patient selection process is shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. This retrospective study was approved by the Institutional Review Board (IRB approval number: 2017\u0026thinsp;\u0026minus;\u0026thinsp;418). Comprehensive informed consent was obtained from all the patients.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eMeasuring the cross-sectional area of the iliopsoas muscle\u003c/h3\u003e\n\u003cp\u003eThe cross-sectional area of the iliopsoas muscle was measured at the upper end of the L3 vertebral level using ShadeQuest/ ViewR-DG (FUJIFILM), and the sum of the left and right sides was examined (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Abdominal CT was assessed in 5 mm slices within one month before surgery. For 29 patients who did not undergo abdominal CT, PET/CT was substituted.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003ePostoperative complications were classified as severity within 30 days postoperatively using the Clavien\u0026ndash;Dindo classification \u003csup\u003e8\u003c/sup\u003e. This grade also accounted for wound infections opened at the bedside. Grade II complications were defined as those requiring pharmacological treatment with drugs other than those permitted for grade I complications. This includes the administration of blood transfusions and total parenteral nutrition. For example, grade I pulmonary leak refers to a pulmonary leak that persists for 5 days postoperatively with only drain placement using an existing drain, whereas \u0026ge;\u0026thinsp;grade II involves replacement of an existing drain, placement of a new drain, intrapleural adhesion, and treatment under general or local anesthesia. In this study, the patients were divided into two groups: those with complications below grade II and higher than grade II. To assess post-operative complications, patients underwent ECG monitoring for two days, with blood samples and chest X-rays taken on postoperative days 1, 3, and 5. Additional tests were performed as required. The patients were discharged approximately 1 week postoperatively and followed up in the outpatient clinic.\u003c/p\u003e\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e\u003ch2\u003eStatistical analysis\u003c/h2\u003e\u003cp\u003eFisher exact test and multivariable logistic regression analyses were performed on 15 preoperative factors, including the preoperative iliopsoas muscle cross-sectional area, to investigate the predictive factors for the development of postoperative complications of \u0026ge;\u0026thinsp;grade II by the Clavien-Dindo classification within 30 days after surgery. The association of the incidence of each complication with the cross-sectional area of the iliopsoas muscle was evaluated based on its cut-off value. P\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered statistically significant. All statistical analyses were performed using EZR software (Saitama Medical Center, Jichi Medical University, Saitama, Japan \u003csup\u003e9\u003c/sup\u003e) for R (R Foundation for Statistical Computing, Vienna, Austria) was used.\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\u003ch2\u003ePatient characteristics\u003c/h2\u003e\u003cp\u003eThe clinical and pathological characteristics of the 584 patients are shown in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. The patients were divided into two groups according to the Clavien-Dindo grade: 125 patients (21%) had\u0026thinsp;\u0026ge;\u0026thinsp;grade II complications, whereas 459 patients (79%) had\u0026thinsp;\u0026lt;\u0026thinsp;grade II complications.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003ePatient characteristics\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"9\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colspan=\"4\" nameend=\"c8\" namest=\"c5\"\u003e\u003cp\u003eClavien-Dindo grade\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e\u003cp\u003eGrade\u0026thinsp;\u0026lt;\u0026thinsp;II\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e\u003cp\u003eGrade\u0026thinsp;\u0026ge;\u0026thinsp;II\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c9\"\u003e\u003cp\u003e\u003cem\u003eP\u003c/em\u003e Value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNo of patients\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003e459\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e\u003cp\u003e125\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAge [median, years]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e75\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e[70\u0026ndash;87]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e75\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e[70\u0026ndash;88]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e0.24\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSex\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003eFemale\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e213\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e99\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.01*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003eMale\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e246\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e99\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSmoking history\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003eEver\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e282\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e103\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.01*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003eNever\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e177\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e22\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBrinkman index [median]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e440\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e[0-4200]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e900\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e[0-3000]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.01*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHeight [median, cm]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e158.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e[134.3-188.2]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e161.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e[140.3-183.6]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.01*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eWeight [median, kg]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e57.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e[30.1\u0026ndash;99.0]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e58.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e[36.2\u0026ndash;85.5]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e0.12\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBMI [median]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e22.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e[14.7\u0026ndash;36.5]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e22.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e[14.5\u0026ndash;31.1]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e0.96\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLung function\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003e%VC [median]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e104.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e[52.9-151.1]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e100.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e[57.1-164.2]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e0.73\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003eFEV1.0% [median]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e76.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e[41.7-133.3]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e73.2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e[40.3\u0026ndash;100.0]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.01*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ecStage\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e0.13\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003eⅠ\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e346\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e83\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003eⅠⅠ\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e73\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e27\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003eⅠⅠⅠⅠ\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e32\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e14\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eThe iliopsoas muscles areal/[median, mm\u003csup\u003e2\u003c/sup\u003e]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1009\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e[412\u0026ndash;2455]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e797\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e[307\u0026ndash;1755]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.01*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCoexisting disease (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003eHypertension\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e203\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e(44.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e55\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e(44.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e1.00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003eDiabetes mellitus\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e88\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e(19.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e28\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e(22.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e0.45\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003eEmphysema\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e58\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e(12.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e29\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e(23.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e0.01*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003eInterstitial pneumonia\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e22\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e(4.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e(12.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e0.01*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003eCoronary\u003c/p\u003e\u003cp\u003eheart disease\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e27\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e(5.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e(4.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e0.51\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003eCerebrovascular Diseases\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e31\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e(6.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e18\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e(14.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e0.01*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003eGastrointestinal tract disease\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e32\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e(7.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e(4.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e0.54\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003eRenal dysfunction\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e(2.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e(1.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e0.75\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"9\"\u003eBMI: body mass index\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"9\"\u003eVC: vital capacity\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"9\"\u003eFEV1.0: forced expiratory volume in 1 second\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eThe two groups showed significant differences in sex, smoking history, brinkman index, height, FEV1.0% (all P\u0026thinsp;\u0026lt;\u0026thinsp;0.01), and comorbidities (COPD, IP, and cerebrovascular diseases; all P\u0026thinsp;=\u0026thinsp;0.01). The median iliopsoas muscle area was 1009 mm\u003csup\u003e2\u003c/sup\u003e [range, 412\u0026ndash;2455 mm\u003csup\u003e2\u003c/sup\u003e] in patients with \u0026lt;\u0026thinsp;grade II complications and 797 mm\u003csup\u003e2\u003c/sup\u003e [range, 307\u0026ndash;1755 mm\u003csup\u003e2\u003c/sup\u003e] in those with \u0026ge;\u0026thinsp;grade II complications, with significant differences (P\u0026thinsp;\u0026lt;\u0026thinsp;0.01).\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\u003ch2\u003eCut-off value for iliopsoas muscle area to predict complications\u003c/h2\u003e\u003cp\u003eReceiver operating characteristic (ROC) curves were generated to predict complications and cut-off values for the iliopsoas muscle region were determined. The area under the ROC curve was 0.64 (95% CI: 0.59\u0026ndash;0.70, Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eA). The cut-off value was set at the point of maximum Youden's index, and when the iliopsoas muscle area was 813 mm2, the sensitivity and specificity were 70.2% and 52.8%, respectively. The specificity and sensitivity were 70.2% and 52.8%, respectively. However, for clarity in clinical use, the cut-off value was set at 800 mm\u003csup\u003e2\u003c/sup\u003e, in which case the specificity and sensitivity were 71.0% and 51.2%, respectively (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eB).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eUnivariable and multivariable analyses for postoperative complications of ≥ grade 2 by the Clavien–Dindo grading system\u003c/h3\u003e\n\u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e shows the results of the univariable and multivariable analyses of postoperative complications. In the univariable analysis, age (P\u0026thinsp;\u0026lt;\u0026thinsp;0.01), brinkman index (P\u0026thinsp;\u0026lt;\u0026thinsp;0.01), FEV 1.0% (P\u0026thinsp;\u0026lt;\u0026thinsp;0.01), and iliopsoas muscle area of \u0026lt;\u0026thinsp;800 mm\u003csup\u003e2\u003c/sup\u003e (P\u0026thinsp;\u0026lt;\u0026thinsp;0.01) were prognostic factors for postoperative complications of \u0026ge;\u0026thinsp;grade II by the Clavien-Dindo classification. The multivariable analysis showed that sex (P\u0026thinsp;\u0026lt;\u0026thinsp;0.01) and an iliopsoas muscle area of \u0026lt;\u0026thinsp;800 mm\u003csup\u003e2\u003c/sup\u003e (P\u0026thinsp;\u0026lt;\u0026thinsp;0.01) were independent factors associated with postoperative complications.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eUnivariable and multivariable analysis of postoperative complications of Clavien- Dindo grade II or higher\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"9\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u003cp\u003eUnivariable analysis\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e\u003cp\u003eMultivariable analysis\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eOdd\u003c/p\u003e\u003cp\u003e(95%CI)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cem\u003eP\u003c/em\u003e Value\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003eOdd\u003c/p\u003e\u003cp\u003e(95%CI)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" 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colname=\"c7\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e0.08\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e≧\u0026thinsp;400\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3.04\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e(1.94\u0026ndash;4.77)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e1.71\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e(0.92\u0026ndash;3.16)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" 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colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e1.16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e(0.41\u0026ndash;2.46)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFEV1.0%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e≧\u0026thinsp;70%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.01*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e0.11\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u0026lt; 70%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.50\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e(0.33\u0026ndash;0.77)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.67\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e(0.41\u0026ndash;1.10)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eComorbidity\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNo\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.21\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e0.42\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eYes\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.36\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e(0.84\u0026ndash;2.20)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e1.26\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e(0.72\u0026ndash;2.20)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eThe iliopsoas muscles area(mm\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e≧\u0026thinsp;800\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.01*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.01*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;800\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.39\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e(0.26\u0026ndash;0.58)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.07\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e(0.04\u0026ndash;0.15)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\n\u003ch3\u003eComparison of each complication and iliopsoas muscle cross-sectional area\u003c/h3\u003e\n\u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e shows the 125 patients with complications of \u0026ge;\u0026thinsp;grade II by the Clavien-Dindo classification divided into two groups according to the iliopsoas muscle area, including complications that were duplicated in one patient.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eComparison of each postoperative complication and iliopsoas muscles cross-sectional area\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"7\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colspan=\"5\" nameend=\"c6\" namest=\"c2\"\u003e\u003cp\u003eThe iliopsoas muscles area (mm\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;800\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e\u003cp\u003e≧\u0026thinsp;800\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e\u003cem\u003eP \u003c/em\u003eValue\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNo of patients\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e197\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e387\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e(%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eProlonged air leakage\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e26\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e(13.20) *\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e29\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e(7.49) *\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.04*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePneumonia\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e(5.58) *\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e(3.88) *\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.49\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAtrial fibrillation\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e(6.09) *\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e(2.58) *\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.04*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eEmpyema\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e(2.54) *\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e(0.78) *\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.13\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAcute exacerbation of interstitial pneumonia\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e(2.00) *\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e(1.03) *\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.45\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAtelectasis lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e(1.52) *\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e(1.03) *\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.69\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDelirium\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e(1.52) *\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e(0.52)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.34\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSubcutaneous emphysema\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e(0.00)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e(0.52) *\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.55\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHypoxemia\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e(0.51) *\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e(0.52) *\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e1.00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eWound infection\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e(1.02) *\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e(0.00)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.11\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGastrointestinal ulcer\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e(1.02) *\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e(0.00)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.11\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePostoperative hemorrhage\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e(1.02)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e(0.00)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.11\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCerebrovascular disease\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e(1.02) *\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e(0.00)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.11\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"7\"\u003e* There are some overlapping\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eThe most common complications were prolonged air leakage, pneumonia, atrial fibrillation, empyema, and acute exacerbation of interstitial pneumonia. Patients with an iliopsoas muscle area of \u0026lt;\u0026thinsp;800 mm\u003csup\u003e2\u003c/sup\u003e had significantly more prolonged air leakage and atrial fibrillation than those with an iliopsoas muscle area of \u0026ge;\u0026thinsp;800 mm\u003csup\u003e2\u003c/sup\u003e (all P\u0026thinsp;=\u0026thinsp;0.04).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eOur study examined the preoperative iliopsoas muscle cross-sectional area and postoperative complications after pulmonary lobectomy in older patients with lung cancer. A reduced preoperative iliopsoas muscle area was a risk factor for postoperative complications of Clavien-Dindo classification\u0026thinsp;\u0026ge;\u0026thinsp;grade II. Pulmonary leakage and atrial fibrillation were affected by iliopsoas muscle mass. In particular, the incidence of prolonged air leakage and atrial fibrillation was significantly higher in patients with an iliopsoas muscle cross-sectional area of \u0026lt;\u0026thinsp;800 mm\u003csup\u003e2\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eSarcopenia is defined as a syndrome characterized by the progressive and generalized loss of skeletal muscle mass and strength, with a risk of physical disability, reduced quality of life, and death \u003csup\u003e10\u003c/sup\u003e. However, the criteria for Europeans are unlikely to be directly adaptable to Asians. In 2014\u003csup\u003e2\u003c/sup\u003e and 2020, the Asian Working Group for Sarcopenia (AWGS) defined the diagnostic criteria for Asians. Skeletal muscle areas of various muscles are used as indicators for sarcopenia, one of which is the iliopsoas muscle \u003csup\u003e6,11,12\u003c/sup\u003e. However, there is no fixed consensus on the evaluation methods and cut-off values, which vary from report to report. In Japan, the diagnostic criteria for sarcopenia in patients aged\u0026thinsp;\u0026ge;\u0026thinsp;65 years are used from the AWGS report \u003csup\u003e3\u003c/sup\u003e, but there are no reports examining the risk factors for postoperative complications and each complication in terms of iliopsoas muscle mass limited to older patients.\u003c/p\u003e\u003cp\u003ePrevious reports on the association of lung cancer \u003csup\u003e6,12\u003c/sup\u003e and iliopsoas muscle volume have reported iliopsoas muscle volume to be a risk factor for postoperative complications using PMI (iliopsoas muscle volume sum at the L3 level/(height)\u003csup\u003e2\u003c/sup\u003e) and PVI (iliopsoas muscle cross-sectional area sum/(height)\u003csup\u003e2\u003c/sup\u003e). Vocal cord paralysis and atrial fibrillation have been reported as complications associated with reduced iliopsoas muscle volume \u003csup\u003e12\u003c/sup\u003e. Our results are consistent with those of previous studies. These reports have only reviewed cases not related to age at surgery \u003csup\u003e6,11, 12\u003c/sup\u003e or investigated the incidence of complications in patients aged\u0026thinsp;\u0026ge;\u0026thinsp;65 years \u003csup\u003e13\u003c/sup\u003e. However, there are no reports comparing the risk factors for postoperative complications and each complication in older patients aged\u0026thinsp;\u0026ge;\u0026thinsp;70 years, as in the present study. The iliopsoas muscle area has also been reported to influence postoperative complications in other cancers \u003csup\u003e14,15\u003c/sup\u003e, but no reports have been limited to older patients. Our study is the first to report the association between the iliopsoas muscle area and postoperative complications in older patients among all reports, including those with lung cancer.\u003c/p\u003e\u003cp\u003eAtrial fibrillation after thoracic surgery may have several causes; however, reports suggest that it depends on the procedure. It is 10\u0026ndash;15% lower in case of lobectomy or greater and as high as 20\u0026ndash;30% in case of total pneumonectomy \u003csup\u003e16\u003c/sup\u003e. Risk factors of atrial fibrillation include older age, male sex, and right lung surgery \u003csup\u003e17,18\u003c/sup\u003e. Sympathetic stimulation and atrial dilatation are considered triggering factors, but their pathogenesis is thought to be multifactorial and is not precisely understood \u003csup\u003e19,20\u003c/sup\u003e. The mechanism by which reduced iliopsoas muscle mass leads to the development of atrial fibrillation has not been investigated, and further studies are needed. In our study, more older patients with a low iliopsoas muscle area had pulmonary leakage, and patients with Clavien\u0026ndash;Dindo classification\u0026thinsp;\u0026ge;\u0026thinsp;grade II pulmonary leakage were more likely to be smokers and have a higher Brinkman index score and coexisting emphysema. This was attributed to a decrease in general fitness and sarcopenia, with longer exposure to smoking being associated with emphysema and respiratory function features. Risk factors for persistent postoperative pulmonary leakage include male sex, lower BMI, and operation time, in addition to factors related to surgical manipulation \u003csup\u003e21\u003c/sup\u003e. The development of postoperative complications may be related to various comorbidities in older patients.\u003c/p\u003e\u003cp\u003eThis study has several limitations. First, this was a retrospective study that used a single-center database. However, this is the first large analysis of 584 older patients with lung cancer. Secondly, it is unclear whether the present measurement of the iliopsoas muscle area adequately reflects sarcopenia, a systemic disease. We plan to assess sarcopenia preoperatively according to the AWGS criteria in a future prospective study.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eCross-sectional area of the iliopsoas is a predictor of postoperative complications. In particular, the incidence of pulmonary fistula (prolonged/delayed) and atrial fibrillation was significantly higher in patients with an iliopsoas cross-sectional area of \u0026lt;\u0026thinsp;800 mm\u003csup\u003e2\u003c/sup\u003e. For patients with a smaller iliopsoas muscle area, limited resection should be considered and more careful perioperative management may be necessary.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eBMI\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003ebody mass index\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eCOPD\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003echronic obstructive pulmonary disease\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eIP\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eInterstitial pneumonia\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eVC\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003evital capacity\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eFEV1.0\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eforced expiratory volume in 1 second\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eNSCLC\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003enon-small cell lung cancer\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cem\u003eAcknowledgments\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eWe thank Yasunori Kaminuma for his help in collecting the data. We would like to thank Editage (www.editage.jp) for English language editing.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eCRediT authorship contribution statement\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eShoko Kubota: Conceptualization, Methodology, Formal analysis, Investigation, Resources, Writing - original draft.\u003c/p\u003e\n\u003cp\u003eJoji Samejima: Methodology, Formal analysis, Investigation, Writing \u0026ndash; review \u0026amp; editing.\u003c/p\u003e\n\u003cp\u003eYutaro Koike: Writing \u0026ndash; review \u0026amp; editing.\u003c/p\u003e\n\u003cp\u003eTomohiro Miyoshi: Writing \u0026ndash; review \u0026amp; editing.\u003c/p\u003e\n\u003cp\u003eKenta Tane: Writing \u0026ndash; review \u0026amp; editing.\u003c/p\u003e\n\u003cp\u003eMasashi Wakabayashi : Methodology, Formal analysis, Writing \u0026ndash; review \u0026amp; editing.\u003c/p\u003e\n\u003cp\u003eKeiju Aokage: Writing \u0026ndash; review \u0026amp; editing.\u003c/p\u003e\n\u003cp\u003eMasahiro Tsuboi: Methodology, Formal analysis, Investigation, Writing\u0026ndash; review \u0026amp; editing, Funding acquisition, Supervision\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eFunding information:\u003c/em\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eAvailability of data and material:\u0026nbsp;\u003c/em\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eCode availability:\u0026nbsp;\u003c/em\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eEthics approval:\u0026nbsp;\u003c/em\u003eThis retrospective study was approved by the Institutional Review Board (IRB approval number; 2017-418).\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eConsent to participate:\u003c/em\u003e Informed consent was obtained from all patients.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eConsent for publication:\u003c/em\u003e Not applicable.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eRosenberg IH. 1989 Herman Award lecture. Folate absorption: clinical questions and metabolic answers. \u003cem\u003eAm J Clin Nutr\u003c/em\u003e. 1990;51:531-534.\u003c/li\u003e\n\u003cli\u003eChen LK, Liu LK, Woo J, et al. Sarcopenia in Asia: consensus report of the Asian Working Group for Sarcopenia. \u003cem\u003eJ Am Med Dir Assoc\u003c/em\u003e. 2014;15:95-101.\u003c/li\u003e\n\u003cli\u003eChen LK, Woo J, Assantachai P, et al. Asian Working Group for Sarcopenia: 2019 Consensus Update on Sarcopenia Diagnosis and Treatment. \u003cem\u003eJ Am Med Dir Assoc\u003c/em\u003e. 2020;21:300-307 e302.\u003c/li\u003e\n\u003cli\u003eHamaguchi Y, Kaido T, Okumura S, et al. Proposal for new diagnostic criteria for low skeletal muscle mass based on computed tomography imaging in Asian adults. \u003cem\u003eNutrition\u003c/em\u003e. 2016;32:1200-1205.\u003c/li\u003e\n\u003cli\u003ePrado CM, Lieffers JR, McCargar LJ, et al. Prevalence and clinical implications of sarcopenic obesity in patients with solid tumours of the respiratory and gastrointestinal tracts: a population-based study. \u003cem\u003eLancet Oncol\u003c/em\u003e. 2008;9:629-635.\u003c/li\u003e\n\u003cli\u003eNakamura R, Inage Y, Tobita R, et al. Sarcopenia in Resected NSCLC: Effect on Postoperative Outcomes. \u003cem\u003eJ Thorac Oncol\u003c/em\u003e. 2018;13:895-903.\u003c/li\u003e\n\u003cli\u003eKawaguchi Y, Hanaoka J, Ohshio Y, et al. Does sarcopenia affect postoperative short- and long-term outcomes in patients with lung cancer?-a systematic review and meta-analysis. \u003cem\u003eJ Thorac Dis\u003c/em\u003e. 2021;13:1358-1369.\u003c/li\u003e\n\u003cli\u003eDindo D, Demartines N, Clavien PA. Classification of surgical complications: a new proposal with evaluation in a cohort of 6336 patients and results of a survey. \u003cem\u003eAnn Surg\u003c/em\u003e. 2004;240:205-213.\u003c/li\u003e\n\u003cli\u003eKanda Y. Investigation of the freely available easy-to-use software \u0026apos;EZR\u0026apos; for medical statistics. \u003cem\u003eBone Marrow Transplant\u003c/em\u003e. 2013;48:452-458.\u003c/li\u003e\n\u003cli\u003eCruz-Jentoft AJ, Baeyens JP, Bauer JM, et al. Sarcopenia: European consensus on definition and diagnosis: Report of the European Working Group on Sarcopenia in Older People. \u003cem\u003eAge Ageing\u003c/em\u003e. 2010;39:412-423.\u003c/li\u003e\n\u003cli\u003eHervochon R, Bobbio A, Guinet C, et al. Body Mass Index and Total Psoas Area Affect Outcomes in Patients Undergoing Pneumonectomy for Cancer. \u003cem\u003eAnn Thorac Surg\u003c/em\u003e. 2017;103:287-295.\u003c/li\u003e\n\u003cli\u003eLee J, Moon SW, Choi JS, Hyun K, Moon YK, Moon MH. Impact of Sarcopenia on Early Postoperative Complications in Early-Stage Non-Small-Cell Lung Cancer. \u003cem\u003eKorean J Thorac Cardiovasc Surg\u003c/em\u003e. 2020;53:93-103.\u003c/li\u003e\n\u003cli\u003eMiura H, Sakaguchi K, Ogawa W, Tamori Y. Clinical features of 65-year-old individuals in Japan diagnosed with possible sarcopenia based on the Asian Working Group for Sarcopenia 2019 criteria. \u003cem\u003eGeriatr Gerontol Int\u003c/em\u003e. 2021;21:689-696.\u003c/li\u003e\n\u003cli\u003eLee SJ, Yang YJ, Lee DW, Song SY, Lew DH, Yang EJ. Influence of sarcopenia on postoperative complications in patients undergoing autologous microsurgical breast reconstruction: an inverse probability of treatment weighting analysis. \u003cem\u003eFront Oncol\u003c/em\u003e. 2023;13:1211593.\u003c/li\u003e\n\u003cli\u003eYamagishi S, Okamura Y, Kang W, et al. Impact of Sarcopenic Obesity on Severe Postoperative Complications in Patients with Gastric Cancer Undergoing Gastrectomy. \u003cem\u003eDig Surg\u003c/em\u003e. 2023;40:143-152.\u003c/li\u003e\n\u003cli\u003eShrivastava V, Nyawo B, Dunning J, Morritt G. Is there a role for prophylaxis against atrial fibrillation for patients undergoing lung surgery? \u003cem\u003eInteract Cardiovasc Thorac Surg\u003c/em\u003e. 2004;3:656-662.\u003c/li\u003e\n\u003cli\u003eRoselli EE, Murthy SC, Rice TW, et al. Atrial fibrillation complicating lung cancer resection. \u003cem\u003eJ Thorac Cardiovasc Surg\u003c/em\u003e. 2005;130:438-444.\u003c/li\u003e\n\u003cli\u003eLee SH, Ahn HJ, Yeon SM, et al. Potentially modifiable risk factors for atrial fibrillation following lung resection surgery: a retrospective cohort study. \u003cem\u003eAnaesthesia\u003c/em\u003e. 2016;71:1424-1430.\u003c/li\u003e\n\u003cli\u003eFrendl G, Sodickson AC, Chung MK, et al. 2014 AATS guidelines for the prevention and management of perioperative atrial fibrillation and flutter for thoracic surgical procedures. \u003cem\u003eJ Thorac Cardiovasc Surg\u003c/em\u003e. 2014;148:e153-193.\u003c/li\u003e\n\u003cli\u003eJoshi KK, Tiru M, Chin T, Fox MT, Stefan MS. Postoperative atrial fibrillation in patients undergoing non-cardiac non-thoracic surgery: A practical approach for the hospitalist. \u003cem\u003eHosp Pract (1995)\u003c/em\u003e. 2015;43:235-244.\u003c/li\u003e\n\u003cli\u003eMotono N, Mizoguchi T, Ishikawa M, Iwai S, Iijima Y, Uramoto H. Analysis of risk factors of postoperative complication for non-small cell lung cancer. \u003cem\u003eBMC Pulm Med\u003c/em\u003e. 2024;24:333.\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":"Sarcopenia, Lung cancer, Lung postoperative complications, Iliopsoas muscle","lastPublishedDoi":"10.21203/rs.3.rs-6859480/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6859480/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e\u003cp\u003eSarcopenia was correlated with increased postoperative complications and poor outcomes in patients with lung cancer. The cross-sectional area of the iliopsoas muscle on computed tomography is a relevant indicator of sarcopenia. This study aimed to investigate whether the preoperative cross-sectional area of the iliopsoas muscle is associated with the incidence of postoperative complications after lobectomy.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e\u003cp\u003eThis retrospective study included 584 consecutive patients aged 70 years or older who underwent curative resection for non-small cell lung cancer between 2016 and 2020. The cross-sectional area of the iliopsoas muscle was measured at the level of the third lumbar vertebra, and the cumulative area of both sides was evaluated. Univariable and multivariable analyses were performed to identify the predictors of early postoperative complications (\u0026ge;\u0026thinsp;grade II by the Clavien-Dindo classification) along with the preoperative iliopsoas muscle cross-sectional area.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e\u003cp\u003eThe patients were divided into two groups according to the Clavien-Dindo grade: 125 patients (21%) had\u0026thinsp;\u0026ge;\u0026thinsp;grade II complications, whereas 459 patients (79%) had\u0026thinsp;\u0026lt;\u0026thinsp;grade II complications. The median iliopsoas muscle area was 1009 mm2 [range, 412\u0026ndash;2455 mm2] in patients with \u0026lt;\u0026thinsp;grade II complications and 797 mm2 [range, 307\u0026ndash;1755 mm2] in those with \u0026ge;\u0026thinsp;grade II complications, with significant differences (P\u0026thinsp;\u0026lt;\u0026thinsp;0.01). The calculated cut-off value for the iliopsoas muscle cross-sectional area was 800 mm. The multivariable analysis showed that sex (P\u0026thinsp;\u0026lt;\u0026thinsp;0.01) and an iliopsoas muscle area of \u0026lt;\u0026thinsp;800 mm2 (P\u0026thinsp;\u0026lt;\u0026thinsp;0.01) were independent factors associated with postoperative complications. The most common complications were prolonged air leakage, pneumonia, atrial fibrillation, empyema, and acute exacerbation of interstitial pneumonia. Patients with an iliopsoas muscle area of \u0026lt;\u0026thinsp;800 mm2 had significantly more prolonged air leakage and atrial fibrillation than those with an iliopsoas muscle area of \u0026ge;\u0026thinsp;800 mm2 (all P\u0026thinsp;=\u0026thinsp;0.04).\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e\u003cp\u003eThe cross-sectional area of the iliopsoas muscle is a valuable predictor of postoperative complications after lobectomy. Notably, patients with an iliopsoas muscle cross-sectional area\u0026thinsp;\u0026lt;\u0026thinsp;800 mm\u0026sup2; had significantly higher risks of pulmonary fistula and atrial fibrillation. For patients with a smaller iliopsoas muscle area, limited resection should be considered and more careful perioperative management may be necessary.\u003c/p\u003e","manuscriptTitle":"Association of iliopsoas muscle cross-sectional area with postoperative complications in older lung cancer patients","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-08-19 13:35:56","doi":"10.21203/rs.3.rs-6859480/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-10-08T15:53:05+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-26T09:10:04+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-18T07:05:12+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"325511892119050900733256436337054081587","date":"2025-08-16T16:05:37+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-15T15:29:55+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"208348347781396070063339419918948898912","date":"2025-08-15T12:00:33+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"212857929213753851744074888479754300441","date":"2025-08-11T16:08:09+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-08-11T15:42:37+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-06-11T05:16:12+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-06-11T05:16:04+00:00","index":"","fulltext":""},{"type":"submitted","content":"Journal of Cardiothoracic Surgery","date":"2025-06-10T05:58:09+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":"c216295c-5d71-49c4-856e-cdbbe023e514","owner":[],"postedDate":"August 19th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-01-24T19:38:44+00:00","versionOfRecord":[],"versionCreatedAt":"2025-08-19 13:35:56","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6859480","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6859480","identity":"rs-6859480","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}