Intraoperative management and postoperative outcomes of patients with high body mass index undergoing tubeless anesthesia for non-intubated uniportal video-assisted thoracoscopic surgery: a single-center retrospective propensity score matching study

Introduction

Over the past decade, tubeless anesthesia for non-intubated video-assisted thoracoscopic surgery (NIVATS) has been widely applied in thoracic surgery (1), offering advantages such as reduced anesthetic dosage, shorter hospital stays, less postoperative pain, fewer postoperative complications, and lower hospital costs (2-5). However, most patient selection criteria exclude those with high body mass index (BMI) (6-8). Although some studies have confirmed the safety and feasibility of this procedure in high BMI (H-BMI) patients (9), these studies lack data on intraoperative surgical conditions, anesthetic management, and postoperative outcomes in such patients.

With the mature application of uniportal video-assisted thoracoscopic surgery (UniVATS) in lobectomy (10), non-intubated uniportal video-assisted thoracoscopic surgery (NI-UniVATS) under tubeless anesthesia has emerged to further minimize surgical trauma. Studies have shown that NI-UniVATS is safe and feasible (11), and compared with traditional anesthesia, it exerts a more favorable perioperative impact and results in fewer postoperative complications (7,11).

Therefore, this study aims to analyze the intraoperative management and postoperative outcomes of H-BMI patients undergoing NI-UniVATS with tubeless anesthesia, so as to explore better approaches for its implementation. This will contribute to the adoption and promotion of NI-UniVATS and tubeless anesthesia. We present this article in accordance with the STROBE reporting checklist (available at https://jtd.amegroups.com/article/view/10.21037/jtd-2025-aw-2098/rc).

Methods

Study design

This was a retrospective cohort study, using data from a database of patients who underwent NI-UniVATS under tubeless anesthesia at The Affiliated Hospital of Hebei University between June 2023 and June 2025. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study protocol was approved by the Ethics Committee of The Affiliated Hospital of Hebei University (No. HDFYLL-IIL-2025-027). Due to the retrospective nature of the study, the requirement for informed consent from patients was waived.

Inclusion and exclusion criteria

Inclusion criteria: (I) adult patients scheduled for NI-UniVATS; (II) no obvious contraindications to tubeless anesthesia; (III) all surgeries were evaluated jointly by senior thoracic surgeons experienced in NI-UniVATS and senior anesthesiologists familiar with tubeless anesthesia.

Exclusion criteria: (I) patients who refused the surgical and anesthetic plans; (II) allergies to anesthetic drugs; (III) severe cardiopulmonary dysfunction; (IV) incomplete patient information in electronic medical records.

Control group

Based on some clinical guidelines in China and the obesity threshold (BMI ≥28 kg/m²) commonly used in previous thoracic surgery studies (12). Based on the electronic medical record database, patients with BMI ≥28 kg/m² were assigned to the H-BMI group, and those with BMI <28 kg/m² to the non-high BMI (NH-BMI) group. A total of 38 patients were included in the H-BMI group (14 cases of lobectomy, 23 cases of lung wedge resection, and 1 case of mediastinal tumor resection). During the same period, 376 patients in the NH-BMI group were retrospectively included for matching. A 1:1 propensity score matching (PSM) was performed, and 38 patients in the NH-BMI group (13 cases of lobectomy, 24 cases of lung wedge resection, and 1 case of mediastinal tumor resection) were selected as the control group. Finally, 76 patients were included in the study. To reduce potential sources of bias, all patients were treated by the same surgical and anesthetic teams. For UniVATS, a 3–5 cm incision was made between the 4th and 5th intercostal spaces along the anterior axillary line. At the end of the operation, a 16# thoracic drainage tube was placed in the upper intercostal space. No indwelling urinary catheters were placed preoperatively in any patients.

Anesthetic management

Pre-anesthetic induction preparation

Upon admission to the operating room, an intravenous access was established. Radial artery puncture was performed for invasive arterial blood pressure monitoring, and electrocardiography (ECG), pulse oxygen saturation (SpO₂), and bispectral index (BIS) monitoring were also initiated. Patients were given 0.5 mg penehyclidine hydrochloride and 10 mg dexamethasone. Subsequently, ultrasound-guided thoracic paravertebral nerve block was performed. The ipsilateral thoracic paravertebral space corresponding to the incision was selected, and 20 mL of 0.375% bupivacaine was injected. Ipsilateral vagus nerve block was performed at the C6 level, with 3–5 mL of 2% lidocaine injected.

Anesthetic induction

Anesthetic induction in our center was performed with midazolam (0.05 mg/kg), alfentanil (10 µg/kg), and etomidate (0.2 mg/kg). When the BIS value reached 45, a laryngeal mask was inserted, and the patient was connected to a ventilator for ventilation in synchronized intermittent mandatory ventilation-volume control ventilation (SIMV-VCV) mode, with simultaneous monitoring of end-tidal carbon dioxide (ETCO₂) concentration.

Anesthetic maintenance

Anesthetic maintenance in our center uses a combined intravenous-inhalational anesthesia. Propofol was administered at 1–2 µg/mL via target-controlled infusion (TCI) until the surgical incision was closed; dexmedetomidine was maintained at 0.5 µg/kg/h until 30 minutes before the end of the operation; alfentanil was administered at 0.3 µg/kg/min until pleural closure; and 2–4% desflurane was used until pleural closure.

Ventilator settings

After the completion of anesthetic induction, in case of transient respiratory depression, ventilation was performed in SIMV-VCV mode [tidal volume (VT): 6–8 mL/kg; respiratory rate: 12–15 breaths per minute; inspired oxygen concentration: 100%, 2–4 L/min]. After the establishment of artificial pneumothorax, the ventilator settings were adjusted to VT: 3–4 mL/kg; respiratory rate: 12–15 breaths per minute; inspired oxygen concentration: 100%, 2–4 L/min, until the patient’s spontaneous breathing recovered to an ideal level (VT: 3–4 mL/kg, respiratory rate: 12–15 breaths per minute), with the inspired oxygen concentration maintained at 100% (2–4 L/min).

Intraoperative special management

According to the intraoperative respiratory movement and mediastinal shift, senior thoracic surgeons experienced in NI-UniVATS determined whether anesthetic adjustments by anesthesiologists were necessary. Anesthesiologists adjusted the TCI infusion rate of alfentanil or administered 0.5–2 mg cisatracurium to ensure the smooth progress of the surgery.

Management of intraoperative adverse events

The criteria for converting to double-lumen endotracheal intubation during surgery included:

• Hypoxemia: SpO₂ <85%, with no improvement in blood oxygen saturation after assisted ventilation (manual/SIMV).
• Hypercapnia: arterial partial pressure of carbon dioxide (PaCO₂) >80 mmHg, with no improvement after assisted ventilation.
• Persistent surgical difficulty (>5 minutes) caused by excessive expansion of the surgical field.
• Severe bleeding at the surgical wound, resulting in blurred vision of the thoracic surgical field.
• Significant increase in tracheal secretions, especially bloody secretions causing dyspnea and increased airway resistance, with a >30% decrease in spontaneous ventilation VT and a peak inspiratory pressure (Ppeak) >20 cmH₂O during mechanical ventilation.
• Persistent cough (>2 times/min) even after vagus nerve block.

Process of intraoperative conversion to double-lumen endotracheal intubation

A dose of 0.05 mg/kg of cisatracurium was administered, followed by removal of the laryngeal mask airway. Subsequently, double-lumen endotracheal intubation was performed in the lateral decubitus position under the guidance of a fiberoptic bronchoscope. After achieving one-lung isolation, the ventilator parameters were adjusted to a volume control ventilation with positive end-expiratory pressure mode. The specific settings were as follows: VT 6–8 mL/kg; positive end-expiratory pressure 5–10 cm H₂O; respiratory rate 12–15 breaths per minute; and an inspired oxygen concentration of 100% with a fresh gas flow of 2–4 L/min.

Other complications were usually managed in accordance with the measures specified in expert consensus (1,7).

Postoperative thoracic drainage tube removal

The removal of the postoperative thoracic drainage tube was based on previous expert consensus (1), which required: (I) complete re-expansion of the remaining lung; (II) no air leakage when coughing; (III) no abnormalities in the drainage fluid; (IV) thoracic drainage volume: ≤200 mL in 24 hours.

Outcomes

This study mainly analyzed the intraoperative management and postoperative outcomes of H-BMI patients undergoing NI-UniVATS under tubeless anesthesia. Therefore, the evaluated outcomes mainly included: intraoperative anesthetic adjustments by anesthesiologists (the number of medication adjustments required by surgeons based on surgical conditions), operation time (from skin incision to chest closure, in minutes), extubation time (from the end of anesthesia to laryngeal mask removal, in minutes), post-anesthesia care unit (PACU) stay time (from admission to discharge from the PACU, in minutes), Intraoperative complications and conversion (1), postoperative patient complications, postoperative hospital stay (from the date of surgery to the date of discharge, in days), thoracic drainage tube removal time (from postoperative to tube removal, in days), postoperative laboratory indicators (white blood cells, hemoglobin, albumin), and total hospital costs.

Statistical analysis

Statistical analysis was performed using SPSS software (version 22.0). Continuous data are presented as mean ± standard deviation and were compared using the Student’s t-test or the Mann-Whitney U test, as appropriate. Categorical data are expressed as numbers (%) and were compared using the Chi-squared test. A two-sided P value <0.05 was considered statistically significant.

Results

Screening process

Between June 2023 and June 2025, a total of 1,916 patients who underwent VATS at The Affiliated Hospital of Hebei University were initially included. After applying the exclusion criteria, 414 patients were included in this study. Among the excluded patients, 1,153 were treated by other surgical or anesthetic teams, and 349 underwent VATS with mechanical ventilation. PSM was used to reduce and balance baseline confounding factors, and 76 patients were successfully matched. The clinical characteristics of the two groups were basically consistent. The specific patient screening flowchart is shown in Figure 1. The baseline clinical characteristics of the patients are presented in Table 1. There were no significant differences between the H-BMI group and the NH-BMI group in terms of age, gender, surgical type, cardiopulmonary function, and preoperative hemoglobin, leukocyte, and albumin levels.

Figure 1 Participant flow of study population. H-BMI, high body mass index; NH-BMI, non-high body mass index; PSM, propensity score matching; VATS, video-assisted thoracoscopic surgery.

Comparison of surgical conditions (Table 2)

No conversion to intubated VATS occurred in either group during the operation. The number of anesthesia adjustments in the H-BMI group was significantly higher than that in the NH-BMI group (1.39±1.36 vs. 0.29±0.57, P=1×10⁻⁵), with a statistically significant difference. In terms of operation time (122.05±55.55 vs. 110.92±47.45 min, P=0.41), intraoperative blood loss (10.63±10.98 vs. 13.95±17.67 mL, P=0.14), extubation (12.18±18.2 vs. 9.0±7.02 min, P=0.50), and PACU recovery (32.18±12.07 vs. 34.11±19.43 min, P=0.74), the H-BMI group had slightly longer operation time and extubation time, and slightly less intraoperative blood loss and shorter PACU recovery compared with the NH-BMI group, but none of these differences were statistically significant.

Perioperative conditions (Table 3)

No 30-day mortality occurred in either group. On the first postoperative day, there were no statistically significant differences in the rechecked abnormal indicators between the two groups, including hemoglobin (132.34±11.72 vs. 129.61±11.20 g/L, P=0.30), lymphocyte (11.94±3.48 vs. 11.92±3.80 ×10¹²/L, P=0.95), and albumin (38.13±2.58 vs. 37.05±2.93 g/L, P=0.12). Regarding postoperative pulmonary complications (13), in the H-BMI group, there were 4 cases (10.53%) of pleural effusion, 3 cases (7.89%) of atelectasis, and 2 cases (5.26%) of pneumothorax; in the NH-BMI group, the corresponding numbers were 2 cases (5.26%), 2 cases (5.26%), and 3 cases (7.89%). No other pulmonary complications were found. The incidence of complications showed no statistically significant difference (χ²=1.13, P=0.78). There were no statistically significant differences in chest drainage (500.26±553.80 vs. 521.32±523.40 mL, P=0.70), chest tube duration (3.68±2.37 vs. 3.74±2.79 days, P=0.95), and postoperative discharge (4.87±2.52 vs. 4.45±2.69 days, P=0.31) between the two groups.

Cost analysis (Table 2)

Costs were converted to US dollars (USD) based on the real-time exchange rate [1 USD =7.1854 Chinese Yuan (CNY)]. There was no statistically significant difference in total costs between the two groups (5,605.84±1,421.34 vs. 5,350.37±1,511.90, P=0.23).

Intraoperative complications (Table 4)

The NH-BMI group experienced no intraoperative coughing, intraoperative hypercapnia, or intraoperative airway management, whereas the H-BMI group had 1 case of intraoperative coughing, 2 cases of hypercapnia, and 1 case of airway management due to laryngeal mask displacement (2.63%, 5.26%, and 2.63%, respectively; P=0.31, P=0.15, P=0.31). No statistically significant differences were observed between the two groups in mediastinal swing (34.21% vs. 15.78%, P=0.06), hypoxemia (10.52% vs. 2.63%, P=0.16), or Intraoperative bleeding (5.26% vs. 7.89%, P=0.64). Although conversion to double-lumen endotracheal intubation did not occur in these two groups, it was observed in the overall study population with an incidence of 1/414 (0.24%). The reason for conversion was incomplete lung lobe expansion after manual lung inflation at the end of the procedure. After conversion to double-lumen intubation, bronchoscopy revealed bronchial mucus plugging; suction via bronchoscopy resulted in successful lung re-expansion.

Discussion

This study included 38 H-BMI patients who underwent NI-UniVATS under tubeless anesthesia. It was found that compared with NH-BMI patients who received the same anesthesia and surgical procedure, there were no differences in surgical conditions, perioperative laboratory indicators, and medical costs, but there was a difference in the number of intraoperative anesthetic adjustments.

H-BMI has a significant and growing impact on global health, leading to higher mortality and disability rates (14), as well as increased perioperative risks and postoperative complications (15-18). With the development of the concept of enhanced recovery after surgery (ERAS), optimizing perioperative preparation and anesthetic management can improve the postoperative outcomes of H-BMI patients (19). The application of NI-UniVATS under tubeless anesthesia has further improved the perioperative outcomes of H-BMI patients.

In our center, anesthesiologists perform ultrasound-guided thoracic paravertebral nerve block preoperatively. Combined with the application of Uni-VATS, this reduces postoperative pain, shortens hospital stays, and decreases the duration of tube indwelling (20,21). The application of cervical vagus nerve block eliminates the need for thoracic surgeons to perform intrapleural vagus nerve anesthesia (22), avoiding coughing caused by this procedure (23) and reducing the waiting time for anesthesia onset. After the pleura is opened, good collapse of the lung tissue can be observed, allowing immediate manipulation of the lung tissue and shortening the operation time. For H-BMI patients, who have more visceral fat (24), direct visualization of intrapleural vagus nerve block is more complex and time-consuming. Uni-VATS results in shorter operation time, shorter thoracic tube indwelling time, and shorter hospital stay (22). The lack of a significant difference in operation time between patients with different BMI may be related to the application of regional block anesthesia in our center.

Compared with traditional anesthesia, tubeless anesthesia using drug TCI under BIS monitoring reduces the dosage of propofol (2), minimizing its fat accumulation and high maintenance dose in H-BMI patients (25). Dexmedetomidine has effects such as reducing systemic inflammatory response, neuroprotection (26), and immuno-oncological effects (27). Alfentanil provides relatively good postoperative comfort and has a short half-life (28), which may explain the lack of significant differences in the time to laryngeal mask removal and PACU stay time between patients with different BMI. For H-BMI patients, tubeless anesthesia maximally preserves spontaneous breathing and uses low VT during the operation, reducing lung tissue damage caused by high-flow mechanical ventilation (29). This may be responsible for the lack of significant differences in postoperative drainage volume and thoracic tube indwelling time between patients with different BMI. Compared with double-lumen endotracheal intubation, the use of a laryngeal mask reduces airway mucosal damage (30) and alleviates the stress response (31), which may account for the lack of significant differences in postoperative laboratory indicators between patients with different BMI. The absence of a significant difference in costs between patients with different BMI may be related to their similar perioperative outcomes.

H-BMI patients have more fat in the oropharynx and viscera, making airway management relatively more complex (32). Patients with a H-BMI often exhibit mediastinal and visceral fat deposition, which leads to more pronounced changes in intrathoracic pressure distribution during spontaneous breathing and reduced pulmonary compliance. Excessive mediastinal adipose tissue can further amplify the extent of mediastinal movement. Additionally, higher oxygen consumption, limited pulmonary reserve (33), increased CO₂ production, and elevated airway resistance (34) in obese patients predispose them to a greater incidence of hypoxemia and hypercapnia. These factors collectively contribute to a higher frequency of intraoperative complications in H-BMI patients, necessitating more frequent intraoperative anesthetic adjustments. No conversion to double-lumen endotracheal intubation occurred in either group, which may be attributed to the surgical proficiency and effective anesthetic coordination at our center. Surgeons must adapt to performing thoracic surgery with the lung under spontaneous ventilation, while anesthesiologists need to perform precise regional nerve blocks and manage intraoperative anesthesia meticulously. It is recommended that experience be gained with a certain number of cases before attempting procedures on H-BMI patients. In addition, team collaboration is also crucial; experienced and well-coordinated anesthesiologists and surgeons can better complete complex surgical procedures (35).

The benefits of NIVATS under tubeless anesthesia for patients have been increasingly demonstrated (36). Recent studies indicate that, compared to traditional double-lumen endotracheal intubation in video-assisted thoracic surgery, tubeless anesthesia during NIVATS reduces postoperative diaphragmatic dysfunction and pulmonary complications (37,38), lowers the risk of postoperative cognitive impairment (39), and the application of thoracic paravertebral nerve blockade shortens both operative time and hospital stay (40).

In this study, the H-BMI group achieved similar perioperative outcomes and cost outcomes to the NH-BMI group. However, its implementation requires an experienced team with well-established protocols for managing intraoperative complications, anesthetic modulation, and safe, timely conversion to double-lumen endotracheal intubation. While this study preliminarily confirms that NIVATS under tubeless anesthesia can be performed in selected high-BMI patients by an experienced multidisciplinary team with thorough preoperative assessment and meticulous intraoperative adjustment, it is not suitable for all patients in this population. It also raises new challenges, such as how to achieve better anesthetic management to maintain more stable intraoperative conditions and how to improve the collaboration between surgeons and anesthesiologists. We believe that with the joint efforts of surgeons and anesthesiologists, this technology will benefit more patients.

Study limitations

Since this study aimed to explore the feasibility of performing NIVATS in patients with a specific BMI cutoff, it is an exploratory investigation. Given the limited data on the application of this technique in obese patients, no a priori sample size estimation was conducted during the study design phase. Additionally, this is a single-center retrospective study and lacks support from multicenter studies with large samples. Retrospective studies are susceptible to potential selection bias. Furthermore, the collected data did not include comparisons of long-term outcomes. Future prospective studies with larger sample sizes are needed to validate the conclusions.

Conclusions

In conclusion, despite the above limitations, our study found that H-BMI does not have a negative impact on the surgical conditions, perioperative outcomes, nor medical costs of NI-UniVATS under tubeless anesthesia, but it requires more intraoperative anesthetic adjustments. This information helps thoracic surgeons and anesthesiologists provide better treatment for H-BMI patients. H-BMI should not be considered a risk factor for tubeless anesthesia. Further well-designed prospective large-scale studies are needed to explore the final perioperative outcomes and more comprehensive adjustment protocols.

Acknowledgments

We appreciate all the medical staff of Hefei Li’s team in the Thoracic Surgery Department and Yongle Li’s team in the Anesthesiology Department of The Affiliated Hospital of Hebei University.

Footnote

Reporting Checklist: The authors have completed the STROBE reporting checklist. Available at https://jtd.amegroups.com/article/view/10.21037/jtd-2025-aw-2098/rc

Data Sharing Statement: Available at https://jtd.amegroups.com/article/view/10.21037/jtd-2025-aw-2098/dss

Peer Review File: Available at https://jtd.amegroups.com/article/view/10.21037/jtd-2025-aw-2098/prf

Funding: This study was supported by the Medical Science Foundation of Hebei University (grant No. 2021A12).

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://jtd.amegroups.com/article/view/10.21037/jtd-2025-aw-2098/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study protocol was approved by the Ethics Committee of The Affiliated Hospital of Hebei University (No. HDFYLL-IIL-2025-027). Due to the retrospective nature of the study, the requirement for informed consent from patients was waived.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. He J, Liu J, Zhu C, et al. Expert consensus on tubeless video-assisted thoracoscopic surgery (Guangzhou). J Thorac Dis 2019;11:4101-8. [Crossref] [PubMed]
2. Mihatsch LL, Huber A, Weiland S, et al. Prospective in-depth analysis of anaesthetic management of spontaneous ventilation VATS for lung cancer resection: a matched pairs comparison to intubated VATS. BMC Anesthesiol 2025;25:185. [Crossref] [PubMed]
3. Zhang XX, Song CT, Gao Z, et al. A comparison of non-intubated video-assisted thoracic surgery with spontaneous ventilation and intubated video-assisted thoracic surgery: a meta-analysis based on 14 randomized controlled trials. J Thorac Dis 2021;13:1624-40. [Crossref] [PubMed]
4. Wang J, Zhou Y, Jiang Z, et al. Cost-effectiveness and postoperative outcomes of spontaneous vs. mechanical ventilation during video-assisted thoracoscopic surgery: a retrospective study. J Thorac Dis 2024;16:6888-98. [Crossref] [PubMed]
5. Lu W, Deng H, Ai Q, et al. Comparison of short-term outcomes between non-intubated and intubated video-assisted thoracoscopic surgery: a propensity score matching analysis. J Thorac Dis 2025;17:9763-73. [Crossref] [PubMed]
6. Udelsman BV, Jang A, Muniappan A, et al. Perioperative morbidity and 3-year survival in non-intubated thoracoscopic surgery: a propensity matched analysis. J Thorac Dis 2024;16:1180-90. [Crossref] [PubMed]
7. He J, Liang H, Wang W, et al. Tubeless video-assisted thoracic surgery for pulmonary ground-glass nodules: expert consensus and protocol (Guangzhou). Transl Lung Cancer Res 2021;10:3503-19. [Crossref] [PubMed]
8. Furák J, Zsoldos P, Lantos J, et al. Impact of spontaneous ventilation with intubation on perioperative results in uniportal VATS lobectomy compared to general anaesthesia using a double-lumen tube. J Thorac Dis 2025;17:774-83. [Crossref] [PubMed]
9. Wu D, Liang H, Liang W, et al. Spontaneous ventilation video-assisted thoracoscopic surgery for patients with non-small-cell lung cancer with excess body weight. Eur J Cardiothorac Surg 2020;58:605-12. [Crossref] [PubMed]
10. Fieira Costa E, Delgado Roel M, Paradela de la Morena M, et al. Technique of uniportal VATS major pulmonary resections. J Thorac Dis 2014;6:S660-4. [Crossref] [PubMed]
11. Agar M, Gulcek I, Kalkan M, et al. Current New Approach in Thoracoscopic Surgery: Non-Intubated Uniportal Video-Assisted Thoracoscopic Surgery (NI-UniVATS). Medicina (Kaunas) 2025;61:641. [Crossref] [PubMed]
12. Bajaj SS, Zhong A, Zhang AL, et al. Body Mass Index Thresholds for Asians: A Race Correction in Need of Correction? Ann Intern Med 2024;177:1127-9. [Crossref] [PubMed]
13. Jammer I, Wickboldt N, Sander M, et al. Standards for definitions and use of outcome measures for clinical effectiveness research in perioperative medicine: European Perioperative Clinical Outcome (EPCO) definitions: a statement from the ESA-ESICM joint taskforce on perioperative outcome measures. Eur J Anaesthesiol 2015;32:88-105. [Crossref] [PubMed]
14. Chen Y, Ma L, Han Z, et al. The global burden of disease attributable to high body mass index in 204 countries and territories: Findings from 1990 to 2019 and predictions to 2035. Diabetes Obes Metab 2024;26:3998-4010. [Crossref] [PubMed]
15. Areti A, Montanez B, Perake V, et al. Impact of morbid obesity on postoperative outcomes in reverse total shoulder arthroplasty: A national inpatient sample analysis. J Orthop 2025;68:84-9. [Crossref] [PubMed]
16. Sun J, Hwang J, Fredette JD, et al. Preoperative weight loss and postoperative pancreatic fistula risk affected by body mass index: a National Surgical Quality Improvement Program study. J Gastrointest Surg 2025;29:102157. [Crossref] [PubMed]
17. Kim D, Kim IC, Youn JC, et al. Impact of obesity on long term post heart transplantation outcomes. J Heart Lung Transplant 2025;44:1396-404. [Crossref] [PubMed]
18. Ahmed-Issap A, Jain S, Habib A, et al. Impact of Extremes of BMI on Outcomes following Lung Resection. Thorac Cardiovasc Surg 2024;72:379-86. [Crossref] [PubMed]
19. Fanaki M, Haidopoulos D, Vlachos DE, et al. Theimpact of obesity on perioperative care: Integrating ERAS protocols for improved surgical outcomes. Maturitas 2025;199:108598. [Crossref] [PubMed]
20. Jiang L, Zhang D, Wu X, et al. The impact of ultrasound-guided thoracic paravertebral nerve block on the quality of recovery after video-assisted thoracoscopic surgery: a meta-analysis of randomized controlled trials. Perioper Med (Lond) 2025;14:83. [Crossref] [PubMed]
21. Watanabe T, Tanahashi M, Chiba M, et al. Postoperative Pain Reduction and Clinical Value of Uniportal Video-Assisted Thoracic Surgery: A Secondary Analysis of the J-RATSIG 01 Study. Clin Lung Cancer 2025;26:e413-e419.e2.
22. Ni H, Li Y, Shen G, et al. Advances in vagus nerve management strategies in thoracoscopic lung resections: a narrative review. J Thorac Dis 2025;17:5298-308. [Crossref] [PubMed]
23. Gong WY, Yue XF, Cheng C, et al. The application of cervical vagus nerve block in the awake video-assisted thoracic surgery for bullectomy. Anaesth Crit Care Pain Med 2021;40:100823. [Crossref] [PubMed]
24. Luo J, Wang Y, Mao J, et al. Features, functions, and associated diseases of visceral and ectopic fat: a comprehensive review. Obesity (Silver Spring) 2025;33:825-38. [Crossref] [PubMed]
25. Absalom AR, Mani V, De Smet T, et al. Pharmacokinetic models for propofol--defining and illuminating the devil in the detail. Br J Anaesth 2009;103:26-37. [Crossref] [PubMed]
26. Feng T, Yao J, Chen Y, et al. Dexmedetomidine attenuates postoperative delirium by activating Nrf2 to reduce oxidative stress and blood-brain barrier disruption. Brain Res Bull 2025;230:111523. [Crossref] [PubMed]
27. Bezu L, Kepp O, Kroemer G. Immuno-oncological effects of the α2-adrenoceptor agonist dexmedetomidine. Oncoimmunology 2025;14:2542334. [Crossref] [PubMed]
28. Gaszynski TM, Strzelczyk JM, Gaszynski WP. Post-anesthesia recovery after infusion of propofol with remifentanil or alfentanil or fentanyl in morbidly obese patients. Obes Surg 2004;14:498-503; discussion 504.
29. Guay J, Ochroch EA, Kopp S. Intraoperative use of low volume ventilation to decrease postoperative mortality, mechanical ventilation, lengths of stay and lung injury in adults without acute lung injury. Cochrane Database Syst Rev 2018;7:CD011151. [Crossref] [PubMed]
30. Mu G, Chen S, Chen X, et al. Hydrogen regulated pyroptosis through NLRP3-GSDMD pathway to improve airway mucosal oxidative stress injury induced by endotracheal tube cuff compression. Free Radic Biol Med 2024;224:287-300. [Crossref] [PubMed]
31. Cao S, Kan M, Jia Y, et al. Index of Consciousness monitoring may effectively predict and prevent circulatory stress induced by endotracheal intubation under general anesthesia: a prospective randomized controlled trial. BMC Anesthesiol 2024;24:316. [Crossref] [PubMed]
32. Kristensen MS. Airway management and morbid obesity. Eur J Anaesthesiol 2010;27:923-7. [Crossref] [PubMed]
33. Deng S, Mei S, Zhou Q, et al. Characteristics of cardiopulmonary exercise capacity in adults with different degrees of obesity. Front Physiol 2024;15:1466153. [Crossref] [PubMed]
34. Astete BM, Lacassie QHJ, Kattan TE, et al. Perioperative Ventilatory Management in the Obese Patient. Rev Med Chil 2025;153:214-24. [Crossref] [PubMed]
35. Cooper JB. Critical Role of the Surgeon-Anesthesiologist Relationship for Patient Safety. J Am Coll Surg 2018;227:382-6. [Crossref] [PubMed]
36. Zheng J, Liang H, Wang R, et al. Perioperative and long-term outcomes of spontaneous ventilation video-assisted thoracoscopic surgery for non-small cell lung cancer. Transl Lung Cancer Res 2021;10:3875-87. [Crossref] [PubMed]
37. Tan Y, Chen Z, Ji W, et al. Effect of non-intubated anaesthesia video-assisted thoracoscopic surgery on postoperative diaphragm function and pulmonary complications in patients undergoing lung surgery: a randomized clinical trial. Int J Surg 2026;112:3213-22. [Crossref]
38. Zhang D, Wu J, Yang Y, et al. Comparison of non-intubated and intubated video-assisted thoracoscopic surgery for perioperative complications-a systematic review and meta-analysis. BMC Anesthesiol 2025;25:272. [Crossref] [PubMed]
39. Zhang L, Lao Y, Zhang Y. Effects of non-intubated spontaneous breathing on cerebral oxygen saturation and postoperative cognition in elderly patients with lung cancer undergoing video-assisted thoracoscopic surgery. Med Gas Res 2025; Epub ahead of print. [Crossref]
40. Temel U, Derdiyok O, Oğuzhan Özyurtkan M. Awake videothoracoscopic anatomic lung resections for non-small cell lung cancer under thoracic paravertebral block: clinical experiences. BMC Surg 2025;25:265. [Crossref] [PubMed]