Abstract
Background
Non-intubated video-assisted thoracoscopic surgery (niVATS) avoids endotracheal intubation and one-lung mechanical ventilation. Whether this translates into clinically meaningful benefits compared with intubated video-assisted thoracoscopic surgery (VATS) requires comparative studies. Evidence from European centers, particularly for major pulmonary resections, remains limited. We evaluated technical feasibility and perioperative outcomes in a selected European niVATS cohort.
Methods
This retrospective single-center observational study included consecutive patients selected to undergo niVATS between May 2018 and February 2025. The primary endpoint was intraoperative conversion to intubated anesthesia. Secondary endpoints included postoperative complications, chest tube duration, length of stay, reoperation, and 30-day mortality.
Results
A total of 163 patients were included. Median age was 67 years and median body mass index (BMI) was 24 kg/m2. Anatomical lung resections were performed in 77 patients (47.2%), including 50 lobectomies and 27 segmentectomies. Conversion to intubated anesthesia occurred in 6 patients (3.7%). Prolonged air leak was observed in 21 patients (12.9%), pneumonia in 5 (3.1%), and reoperation in 6 (3.7%). Thirty-day mortality was 1.2%. Median chest tube duration and hospital stay were 3 and 5 days, respectively. Conversion was more frequently observed among patients undergoing lobectomy and among those with a higher BMI.
Conclusions
niVATS is feasible in selected patients across a broad spectrum of thoracic procedures in a high-volume European center. Lobectomy and increasing BMI are associated with a higher likelihood of conversion and should be considered during patient selection and perioperative planning. These descriptive findings do not establish comparative safety or clinical benefit versus intubated VATS; prospective comparative studies are required.
Keywords: Lobectomy, segmentectomy, non-intubated video-assisted thoracoscopic surgery (niVATS)
Highlight box.
Key findings
• In this single-center European cohort of 163 selected patients, non-intubated uniportal video-assisted thoracoscopic surgery (VATS) was feasible for a broad range of minor and major pulmonary procedures.
• Anatomical pulmonary resections accounted for 47.2% of procedures, including 50 lobectomies and 27 segmentectomies.
• Conversion to intubated anesthesia was required in 6 patients (3.7%) and was performed safely without airway-related complications.
• Higher body mass index and lobectomy were associated with an increased likelihood of conversion.
What is known and what is new?
• Evidence on non-intubated major pulmonary resections has predominantly originated from high-volume Asian centers, whereas European experience remains limited.
• This study adds one of the larger European single-center series including both minor and major pulmonary resections under spontaneous ventilation.
• The findings demonstrate the feasibility of non-intubated uniportal VATS for selected patients, including anatomical lung resections, while identifying factors associated with conversion.
What is the implication, and what should change now?
• Non-intubated VATS may be incorporated into experienced multidisciplinary thoracic surgery and anesthesia programs for carefully selected patients.
• Conversion to intubated anesthesia should be considered a predefined safety strategy rather than a procedural failure.
• The results do not establish superiority over conventional intubated VATS. Prospective multicenter comparative studies are needed to determine whether the potential physiological benefits translate into clinically meaningful outcomes.
Introduction
Increasing life expectancy and the growing prevalence of chronic cardiopulmonary disease (1) have resulted in a larger population of patients requiring thoracic surgical intervention despite substantial perioperative risk. Video-assisted thoracoscopic surgery (VATS) and enhanced recovery pathways have substantially improved postoperative outcomes and expanded surgical eligibility among high-risk patients (2). Nevertheless, conventional thoracic surgery is still commonly performed under general anesthesia with endotracheal intubation and one-lung ventilation, both of which may contribute to airway trauma, ventilator-induced lung injury, residual neuromuscular blockade, postoperative pulmonary complications, and delayed recovery (3-6).
Coupled with the development of locoregional anesthetic techniques like paravertebral and musculus erector spinae plane block (6,7), minimally invasive procedures have facilitated the realization and adaptation of non-intubated surgical lung resection. This approach combines minimal sedation without muscle relaxants with the avoidance of endotracheal tube placement and mechanical ventilation. This technique may reduce the risks associated with intubation and general anesthesia and may support patient recovery in selected settings (3). Additionally, non-intubated video-assisted thoracoscopic surgery (niVATS) appears to be associated with fewer pulmonary complications and a milder systemic inflammatory response (8).
Despite increasing interest in niVATS, most published experience with major anatomical pulmonary resections originates from high-volume Asian centers (9). European data remain limited, particularly regarding lobectomy and segmentectomy performed under spontaneous ventilation. As we do have robust experience with both minor and major niVATS procedures (10,11), our primary objective was to evaluate perioperative feasibility and safety, while the secondary objective was to identify factors associated with intraoperative conversion to intubated anesthesia. We present this article in accordance with the STROBE reporting checklist (available at https://jtd.amegroups.com/article/view/10.21037/jtd-2026-1579/rc).
Methods
Study design
After approval by Ethics Committee of the Hannover Medical School (No. 12322_BO_K_2026) and waiver of individual consent due to its retrospective character, we conducted the study in accordance with the Declaration of Helsinki and its amendments. The primary endpoint was conversion to intubated anesthesia. Secondary endpoints included postoperative complications, chest tube duration, length of hospital stay, reoperation, and 30-day mortality. We then investigated our institutional records to collect preoperative patient characteristics, type of performed procedure, histology findings, preoperative lung function data, postoperative course, and complications for all patients that underwent niVATS major and/or minor pulmonary resection between May 2018 and February 2025.
Patient selection
Indications for niVATS pulmonary resection included diagnostic procedures for undetermined lung disease, curative treatment for primary lung cancer or metastatic disease and lung volume reduction surgery (LVRS) for chronic obstructive lung disease (COPD). Patients were selected for niVATS through multidisciplinary surgical and anesthesiological assessment. Relative contraindications for niVATS included a known or predicted difficult airway, expected intra-thoracic adhesions, obesity with body mass index (BMI) >35 kg/m2, ongoing therapeutic oral anticoagulation and pulmonary hypertension. The retrospective dataset did not include a complete screening log of all pulmonary resections, patients considered but not selected for niVATS, patient refusal, or clinician-specific reasons for selection; therefore, the denominator from which the niVATS cohort was selected cannot be reliably reconstructed.
Anesthesiologic management
We previously described our niVATS lung resection management in greater detail elsewhere (11). Standard monitoring includes respiratory rate, approximation of end-tidal carbon dioxide monitoring (etCO2), non-invasive blood pressure measurement, pulse oximetry and electrocardiogram (ECG). All patients received 1–2 peripheral intravenous lines (> G18) and oxygen supplementation (4–8 L/min) via face mask or, in selected cases, laryngeal mask during the procedure, which allows sampling of exhaled carbon dioxide in non-intubated patients. Both strategies were categorized as non-intubated anesthesia because no endotracheal tube or planned one-lung mechanical ventilation was used at induction. However, these airway-management strategies are not physiologically identical, and the retrospective dataset did not consistently capture detailed ventilatory-support settings or airway-strategy-specific outcomes. Oxygen supplementation aimed to keep the saturation of peripheral oxygen (SpO2) above 92%. To prevent coughing from hilar manipulation and lung traction, 3 mL of 2% lidocaine was nebulized before induction and immediately prior to surgery (Flexicare Dual MaskTM, Flexicare Medisize, Germany; Aeroneb Pro XTM, WKM GmbH, Mönchengladbach, Germany). An intrathoracic vagal nerve block with 2–5 mL of 0.5% ropivacaine was performed in all patients that underwent major resection and selected cases of minor resections. Across the study period, various regional techniques were used, contributing to a heterogeneous anesthetic exposure profile. In our early phase, thoracic epidural analgesia (TEA) was provided with a catheter inserted at T4–T5 in the sitting position. After a 3 mL test dose of 0.5% bupivacaine, 8–10 mL of 0.2% ropivacaine and 10 µg sufentanil were administered to achieve adequate sensory block while preserving diaphragmatic movement. Patient-controlled epidural analgesia was delivered via an automated pump (CADDTM, Smiths Medical, Kent, UK). Since mid 2020 we switched our approach to either paravertebral block or musculus erector spinae plane block under ultrasound guidance. When percutaneous approaches were not feasible, a transthoracic intercostal block under direct thoracoscopic view was implemented.
Sedation was maintained with continuous dexmedetomidine infusion (200 µg/50 mL), starting at 3 µg/kg/h for 10 min and titrated to 0.5–1 µg/kg/h. If sedation or analgesia was insufficient, small boluses of sufentanil or propofol were given.
Patients were positioned in a lateral decubitus position on a bean bag and the target lung collapsed after thoracic incision. Whenever oxygen saturation dropped below 90%, a chest tube under suction led to temporary re-expansion of the lung that underwent surgery. Induction of general anesthesia in case of conversion was performed with propofol (1–2 mg/kg), sufentanil (0.2 µg/kg), and rocuronium (0.5 mg/kg) and maintained with additional sevoflurane or propofol (5 mg/kg/h). Airway control was achieved either with a standard double-lumen tube or bronchial blocker (EZ-BlockerTM, Teleflex, Fellbach, Germany; Arndt Blocker Set, Cook Medical, Limerick, Ireland) placed under video laryngoscopic and/ or fiber-optic guidance (C-MacTM, KARL STORZ, Tuttlingen, Germany). General anesthesia was induced when severe hypoxemia [partial pressure of oxygen (PaO2) <60 mmHg], severe hypercapnia with acidosis (pH <7.1), hemodynamic instability, persistent cough in spite of intrathoracic vagal nerve blockade, excessive diaphragmatic/mediastinal movement, failure of regional anesthesia, incomplete iatrogenic pneumothorax, and/or surgical complications (major bleeding, lack of progress, adhesions, unexpected findings) occurred. In practice, the decision to convert was made by the surgical-anesthesia team when patient safety or operative feasibility was judged to be compromised.
Technique of thoracoscopic surgery
All procedures were performed through a single 3 cm incision located in the 4th interspace in the medioclavicular line through a soft tissue retractor (SurgiSleeve size S, Medtronic, Minneapolis, MN, USA), and visualization was realized through a 10 mm/30° Video-System (EndoEye, Olympus Germany, Hamburg, Germany). After intrathoracic vagal nerve blockade in major resection and selected cases of minor procedures, standard dissection was performed with dedicated surgical instruments for uniportal surgery (Scanlan Surgical, Saint Paul, MN, USA). Parenchymal resection as well as transecting vessels and bronchi was achieved with Endo-Staplers (Lexington Medical Inc., Bedford, MA, USA). All patients were subsequently scheduled to recover in the post-anesthesia care unit (PACU) after surgery prior to same-day transferal to the surgical ward. Chest tubes were removed whenever less than 300 mL of fluids/24 h and no air leakage (measured on the Medela Thopaz, Medela AG, Baar, Switzerland) were ascertained. After the operation, chest radiography was performed either immediately or the next morning. Liquid and solid intake were resumed 2–4 hours after surgery.
Statistical analysis
All analyses were performed using IBM SPSS Statistics version 30.0 (IBM Corp., Armonk, NY, USA). Continuous variables were assessed for normality using the Shapiro-Wilk and Kolmogorov-Smirnov tests. Normally distributed variables are presented as mean with 95% confidence intervals (CIs), whereas non-normally distributed variables are reported as median and interquartile range (IQR). Categorical variables are presented as absolute numbers and percentages. Comparisons between patients requiring intraoperative conversion to intubated anesthesia and those completing niVATS without conversion were performed using Student’s t-test, Mann-Whitney U-test, Chi-squared test, or Fisher’s exact test, as appropriate. To identify independent predictors of conversion to intubated anesthesia, a multivariable binary logistic regression model was constructed. Candidate variables included age, BMI, side of surgery, pulmonary lobe, procedure type, preoperative blood gas parameters, and American Society of Anesthesiologists (ASA) physical status. Odds ratios (ORs) with corresponding 95% CIs were calculated. A two-sided P value <0.05 was considered statistically significant.
Results
Between May 2018 and February 2025, 163 consecutive selected patients underwent non-intubated uniportal VATS pulmonary procedures at our institution. Baseline demographic, pulmonary function, histological, anesthetic, and perioperative characteristics are summarized in Tables 1-7. The median age was 67 years, and the median BMI was 24 kg/m2. Most patients were classified as ASA III. Anatomical pulmonary resections accounted for nearly half of all procedures and included lobectomies and segmentectomies. Our non-intubated series comprised heterogeneous airway strategies but separate outcome analyses by airway device were not possible based on the available source material. Intraoperative conversion to endotracheal intubation was required in six patients (3.7%). All conversions were safely performed in the lateral decubitus position without airway-related complications. Reasons for conversion included excessive mediastinal movement, extensive pleural adhesions, intraoperative esophageal injury requiring open repair, unexpected need for sleeve resection, and severe anxiety combined with severe adhesions.
Table 1. Baseline patient characteristics of study cohort.
| Patient characteristics | All (n=163) | No conversion (n=157) | Conversion (n=6) | P value |
|---|---|---|---|---|
| Age (years)† | 67.1 [59.8, 75.5] | 67.2 [59.7, 75.6] | 62.3 [53.2, 67.8] | 0.26 |
| Sex | 0.49 | |||
| Male | 103 (63.2) | 100 (63.7) | 3 (50.0) | |
| Female | 60 (36.8) | 57 (36.3) | 3 (50.0) | |
| BMI (kg/m2)† | 24 [22, 28] | 24 [22, 28] | 28.5 [25, 32] | 0.03 |
| Smoking | 0.60 | |||
| Yes | 98 (60.1) | 95 (60.5) | 3 (50.0) | |
| No | 65 (39.9) | 62 (39.5) | 3 (50.0) | |
| ASA physical status classification† | 0.82 | |||
| I | 4 (2.5) | 4 (2.5) | – | |
| II | 58 (35.6) | 56 (35.7) | 2 (33.3) | |
| III | 98 (60.1) | 94 (59.9) | 4 (66.6) | |
| IV | 3 (1.8) | 3 (1.9) | – | |
| PONV risk score | 0.71 | |||
| 0: none | 1 (0.6) | 1 (0.6) | 0 | |
| 1: mild | 18 (11.0) | 17 (10.8) | 1 (16.7) | |
| 2: mild to moderate | 94 (57.7) | 91 (58.0) | 3 (50.0) | |
| 3: moderate | 44 (27.0) | 43 (27.4) | 1 (16.7) | |
| 4: severe | 5 (3.1) | 4 (2.5) | 1 (16.7) | |
| 5: extreme | 1 (0.6) | 1 (0.6) | 0 |
Data are shown as median [interquartile range] or n (%). †, non-normally distributed factors, they are compared by MWU, others by T. ASA, American Society of Anesthesiologists; BMI, body mass index; MWU, Mann-Whitney U-test; PONV, postoperative nausea/vomiting; T, t-test.
Table 2. Preoperative respiratory and pulmonary function parameters.
| Preoperative respiratory parameters | All (n=163) | No conversion (n=157) | Conversion (n=6) | P value |
|---|---|---|---|---|
| Capillary pO2 (mmHg) | 77.9 (75.8, 79.9) (n=149) | 77.9 (75.8, 80.0) (n=143) | 78.0 (63.4, 92.6) (n=6) | 0.98 |
| Capillary pCO2 (mmHg)† | 36.5 (33.8, 40.0) (n=150) | 36.0 (34.0, 40.0) (n=144) | 37.5 (31.5, 41.3) (n=6) | 0.80 |
| FEV1 (L) | 2.2 (2.1, 2.4) (n=153) | 2.2 (2.1, 2.4) (n=147) | 2.2 (1.9, 2.6) (n=6) | 0.91 |
| Predicted FEV1 (L)† | 2.9 (2.3, 3.4) (n=155) | 2.9 (2.3, 3.4) (n=95) | 3.0 (2.9, 3.6) (n=4) | 0.31 |
| FEV1/VCmax (%)† | 71 (61, 80) (n=153) | 71 (61, 81) (n=147) | 70 (68, 72) (n=6) | 0.76 |
| Predicted FEV1/VCmax (%)† | 76 (75, 78) (n=94) | 76 (75, 78) (n=90) | 77 (74, 82) (n=4) | 0.56 |
| Predicted DLCO (%) | 67.7 (62.1, 73.4) (n=108) | 68.2 (62.5, 74.0) (n=105) | 49.3 (−20, 118.0) (n=3) | 0.27 |
Data are shown as median (interquartile range). †, non-normally distributed factors, they are compared by MWU, others by T. DLCO, diffusing capacity of the lungs for carbon monoxide; FEV1, forced expiratory volume in one second; MWU, Mann-Whitney U-test; T, t-test; VC, vital capacity.
Table 3. Indications and type of surgical procedure.
| Histology | All (n=163) | No conversion (n=157) | Conversion (n=6) | P value (Chi2 test) |
|---|---|---|---|---|
| BT | 19 (11.7) | 18 (11.5) | 1 (16.7) | 0.96 |
| HL | 2 (1.2) | 2 (1.3) | – | |
| ILD | 31 (19.0) | 31 (19.7) | – | |
| LE | 18 (11.0) | 18 (11.5) | – | |
| LH | 2 (1.2) | 2 (1.3) | – | |
| LM | 25 (15.3) | 24 (15.3) | 1 (16.7) | |
| NSCLC | 52 (31.9) | 49 (31.2) | 3 (50.0) | |
| Adenocarcinoma | 36 (69.2) | 34 (69.4) | 2 (66.6) | |
| Squamous cell carcinoma | 15 (28.8) | 14 (28.5) | 1 (33.3) | |
| Large cell carcinoma | 1 (1.9) | 1 (2.0) | – | |
| NTM | 2 (1.2) | 2 (1.3) | – | |
| PM | 2 (1.2) | 2 (1.3) | – | |
| Others | 10 (6.1) | 9 (5.7) | 1 (16.7) | |
| Type of procedure | 0.72 | |||
| L | 49 (30.1) | 45 (28.7) | 4 (66.7) | |
| Segmentectomy | 27 (16.6) | 27 (17.2) | – | |
| W | 74 (45.4) | 72 (45.9) | 2 (33.3) | |
| B | 4 (2.5) | 4 (2.5) | – | |
| T | 2 (1.2) | 2 (1.3) | – | |
| B & T | 4 (2.5) | 4 (2.5) | – | |
| W & T | 2 (1.2) | 2 (1.3) | – | |
| W & L | 1 (0.6) | 1 (0.6) | – |
Values are shown as n (%). NSCLC cases are further stratified by histological subtype. Others: amyloidosis, empyema, pleura carcinosis. B, biopsy; BT, benign tumor; HL, hodgkin lymphoma; ILD, interstitial lung disease; L, lobectomy; LE, lung emphysema; LH, langerhans cell histiocytosis; LM, lung metastasis; NSCLC, non-small cell lung cancer; NTM, non-tuberculous mycobacterium; PM, pleural mesothelioma; T, talc pleurodesis; W, wedge resection.
Table 4. Intraoperative management and anesthesia techniques.
| Variables | All (n=163) | No conversion (n=157) | Conversion (n=6) | P value (t-test) |
|---|---|---|---|---|
| Intraoperative management | ||||
| Tranexamic acid | 22 (13.5) | 21 (13.4) | 1 (16.7) | 0.81 |
| Blood transfusion | 1 (0.6) | 1 (0.6) | – | 0.84 |
| Anesthesia technique | ||||
| Vagal nerve block | 91 (55.8) | 88 (56.1) | 3 (50.0) | 0.77 |
| Paravertebral block | 65 (39.9) | 63 (40.1) | 2 (33.3) | 0.74 |
| Phrenic nerve block | 4 (2.5) | 4 (2.5) | – | 0.69 |
| LMA | 49 (30.1) | 44 (30.6) | 1 (16.7) | 0.46 |
| PDC | 90 (55.2) | 87 (55.4) | 3 (50.0) | 0.79 |
Values are shown as n (%). In both categories, more than one treatment was possible. LMA, laryngeal mask airway; PDC, peridural catheter.
Table 5. Intraoperative respiratory parameters.
| Intraoperative respiratory parameters | All (n=163) | No conversion (n=157) | Conversion (n=6) | P value (Mann-Whitney-U-test) |
|---|---|---|---|---|
| Minimum respiratory rate (breaths/minute) | 9 (5, 12) | 9 (5, 12) | 6 (5, 11) | 0.44 |
| Maximum respiratory rate (breaths/minute) | 22 (17, 27) | 20 (17, 27) | 25 (23, 32) | 0.12 |
| Minimum SpO2 (%) | 90 (87, 93) | 90 (86, 93) | 84 (81, 90) | 0.051 |
| Maximum SpO2 (%) | 100 (99, 100) | 100 (99, 100) | 100 (98, 100) | 0.25 |
| Minimum SpCO2 (mmHg) | 17 (10, 26) | 17 (10, 26) | 16 (13, 23) | 0.90 |
| Maximum SpCO2 (mmHg) | 38 (30, 51) | 38 (30, 51) | 55 (46, 79) | 0.02 |
Values are shown as median (interquartile range). None of the described factors was normally distributed. SpCO2, pulse carboxyhemoglobin oxygen saturation; SpO2, saturation of peripheral oxygen.
Table 6. Operative duration stratified by type of procedure.
| Operative duration | All (n=163) | No conversion (n=157) | Conversion (n=6) | P value (Mann-Whitney-U-test) |
|---|---|---|---|---|
| Overall mean (min) | 61 (28–97) | 60 (28–95) | 175 (69–265) | 0.005 |
| Wedge resection (min) | 29 (21–46) | 28 (21–43) | 65 (56–) | 0.06 |
| Segmentectomy (min) | 90 (71–123) | 90 (71–123) | – | – |
| Lobectomy (min) | 97 (71–144) | 94 (68–136) | 218 (160–334) | 0.001 |
| Biopsy (min) | 37 (27–46) | 37 (27–46) | – | – |
Values are shown as median (interquartile range).
Table 7. Postoperative management and complications.
| Variables | All (n=163) | No conversion (n=157) | Conversion (n=6) | P value (Mann-Whitney-U-test; t-test) |
|---|---|---|---|---|
| Postoperative management and complications | ||||
| Chest tube duration (days) | 3 [2–5] | 3 [2–5] | 6 [5–9] | 0.02 |
| Time to discharge (days) | 5 [3–8] | 5 [3–7] | 9 [7–11] | 0.03 |
| Complications | ||||
| No postoperative† complication | 139 (85.3) | 133 (84.7) | 6 (100.0) | <0.001 |
| Prolonged air leak (>7 days) | 21 (12.9) | 21 (13.4) | 0 | <0.001 |
| Pneumonia | 5 (3.1) | 5 (3.2) | 0 | 0.65 |
| Reoperation | 6 (3.7) | 6 (3.8) | 0 | 0.62 |
| Bleeding | 0 | 0 | 0 | – |
| 30-day mortality | 2 (1.2) | 2 (1.3) | 0 | 0.78 |
Data are presented as median [interquartile range] or n (%). †, intraoperative complications: 3 intubations, 2 thoracotomies, 3 × both.
Postoperative outcomes were favorable overall. Median chest tube duration was 3 days and median postoperative hospital stay was 5 days. Prolonged air leak occurred in 21 patients (12.9%), pneumonia in 5 patients (3.1%), and reoperation in 6 patients (3.7%) (Figure 1). No clinically relevant postoperative bleeding was observed. Thirty-day mortality was 1.2%.
Figure 1.
Complication(s) overview. Patients with complication(s): 32 of 163. Complication combinations (in brackets number of patients). Connecting lines delineate concurring complications. D, death; F, fistula; I, intubation; P, pneumonia; R, re-operation; T, thoracotomy.
Patients requiring conversion demonstrated significantly higher BMI values, longer operative duration, increased intraoperative carbon dioxide levels, prolonged chest tube duration, and longer postoperative hospital stay.
Multivariable logistic regression analysis suggested an association between lobectomy, increasing BMI, and conversion to intubated anesthesia (Figures 2,3), but the small number of events limits the reliability of the model (Table S1).
Figure 2.
Intubation risk factors. In lobectomy likelihood of conversion to intubation appears to increase in higher BMI. BMI, body mass index.
Figure 3.
Reliability of intubation prediction. ROC, receiver operating characteristic.
Risk factor analysis
Statistically significant differences were observed for: BMI (higher BMI in intubated patients), lobectomy (more frequent in intubated patients), intraoperative CO2 maximum (higher in intubated patients), chest tube duration (longer in intubated patients), days to discharge (more in intubated patients), postoperative complications (less in intubated patients) and prolonged air leak (less in intubated patients). Multivariate comparisons between intubated and non-intubated patients were not feasible as using all procedure classes as potential risk factors did not work properly in the Cox model, due to too many small classes. Therefore, we limited the analysis to patients who underwent one of the 3 most frequent procedures (lobectomy, wedge resection and segmentectomy) as independent risk factors. This choice permitted us to include over 83% of our patients. The stepwise binary logistic regression model (details in Table S1) indicated lobectomy and higher BMI as significant risk factors for unplanned intubation; the regression equation for calculation the conversion probability is given in the legend of Figure 2. Figure 2 is a graphical illustration of BMI distribution stratified by lobectomy vs. non-lobectomy and by intubation. The course of the stepwise binary logistic regression is given in Table S1. Figure 2 shows that the estimation has a statistically significant, but not overwhelming reliability.
Discussion
The present study represents one of the largest reported European experiences with non-intubated uniportal thoracoscopic pulmonary resection and includes a substantial proportion of anatomical lung resections. Our principal findings are that niVATS was associated with a low conversion rate and acceptable perioperative morbidity in a selected cohort. Avoidance of endotracheal intubation and mechanical one-lung ventilation constitutes the major theoretical advantage of niVATS. Mechanical ventilation has been associated with volutrauma, atelectrauma, inflammatory activation, and postoperative pulmonary dysfunction (12-14). Consequently, spontaneous-ventilation techniques may be particularly attractive in patients with limited cardiopulmonary reserve. Our findings support the feasibility of this strategy in carefully selected patients treated within an experienced multidisciplinary program.
A history of smoking was present in the vast majority of our study population, which is a known risk factor for postoperative complications (15), and likely contributes to the observed impairment in pulmonary function. The median age was 67 years, and the predominance of ASA physical status III underscores the presence of substantial systemic comorbidity within the cohort. Earlier data from our group examining the outcome of niVATS for anatomical LVRS in cases with severe COPD suggest that this approach may offer advantages in this subset of patients (11). Factors that truly impede a more widespread adoption of niVATS currently are obesity and technical challenges for anaesthesiologists and surgeons alike. BMI values above 30 kg/m2 are considered significant risk factors for conversion to intubation (16) due to increased diaphragmatic excursion and limited intracavitary space in the chest. In our cohort, 32 patients (19.3%) had a BMI ≥30 kg/m2 and 12 patients even >32 kg/m2. Two of those required intraoperative intubation, but the observed complications in all BMI ≥30 kg/m2 patients were of mild severity. Thus, currently we do not see a need for a strict niVATS threshold at a BMI of 30 kg/m2. Furthermore, non-intubated thoracic surgery remains demanding, especially in view of critical intraoperative issues such as hypercapnia, hypoxemia, coughing, and conversion to intubation with or without thoracotomy. As reported in many studies, surgery under regional anesthesia and minimal sedation in spontaneous breathing may potentially lead to hypercapnia and hypoxemia (17,18). In our cohort, PaCO2 remained in an acceptable range. Moderate hypercapnia (PaCO2 >50 mmHg) occurred in 25% of patients, while the highest recorded PaCO2 was 99 mmHg, which was well tolerated with no need for ventilation support. Pathonsamit et al. reported a similar spike during niVATS that normalized immediately postoperatively (19). Cheng et al. demonstrated that acute mild to moderate hypercapnia (PaCO2 <100 mmHg) does not result in adverse events and is clinically tolerated (20). Oxygenation was adequately maintained. Transient desaturation (SpO2 <90 mmHg) occurred in 84 patients (52%), though all episodes were successfully managed. When the saturation was under 80%, the surgical wound was sealed with a wetted gauze pad after insertion of a chest tube with suction to re-expand the lung. The observed conversion rate of 3.7% compares favorably with previously published series reporting conversion rates between approximately 2% and 11% (21). Importantly, all conversions were performed safely without additional airway-related complications. These findings emphasize that conversion should be regarded as a predefined safety strategy rather than procedural failure.
Another potential concern that has been identified during non-intubated anesthesia is intraoperative coughing, possibly increasing the anesthetic complexity and adding challenges to the surgeon due to inadvertent patient movement. Based on our experience, a selective vagal blockade is fundamental in niVATS and was routinely applied in our patients in all major resections. This allows for a stable working field and good intraoperative overview, which is essential to preserve the safety and integrity of our niVATS procedures. Even though we did not explicitly analyze a correlation between procedure duration and conversion, we observed a tendency towards longer procedures in converted cases. This was most likely related either to additional time required for conversion and/or increased complexity.
Postoperative outcomes were acceptable, but they should be interpreted in the context of patient selection and the heterogeneity of procedures. Prolonged air leak represented the most frequent complication and accounted for most adverse events observed in the cohort. The rates of pneumonia, reoperation, and mortality remained low and were comparable to previously reported niVATS series. Although postoperative pulmonary function was not systematically assessed, the low incidence of respiratory complications is consistent with the proposed physiological advantages of spontaneous-ventilation surgery.
As the study period likely encompassed practice evolution and institutional learning, and the design does not permit robust separation of treatment effect from temporal change, we have to acknowledge several limitations. First, the retrospective single-center design introduces the possibility of selection bias and limits external validity. Second, the absence of a contemporaneous intubated-VATS control group precludes direct comparison of perioperative outcomes, with the additional caveat of anesthetic heterogeneity in the non-intubated group. Third, we acknowledge that the absence of screening and denominator data limits both generalizability and the assessment of selection bias. Fourth, only six conversion events occurred, limiting statistical power for risk-factor analyses. Finally, long-term oncological and functional outcomes were not evaluated.
Conclusions
Despite these limitations, the present study provides descriptive European data regarding the implementation of niVATS for both minor and major pulmonary resections. The findings should be viewed as hypothesis-generating rather than definitive comparative evidence. Prospective multicenter studies are warranted to validate patient-selection criteria, assess long-term outcomes, and determine whether the physiological advantages of niVATS translate into clinically meaningful benefits compared with conventional intubated VATS.
Supplementary
The article’s supplementary files as
Acknowledgments
None.
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. This study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the Ethics Committee of the Hannover Medical School (No. 12322_BO_K_2026) and individual consent for the retrospective analysis was waived.
Footnotes
Reporting Checklist: The authors have completed the STROBE reporting checklist. Available at https://jtd.amegroups.com/article/view/10.21037/jtd-2026-1579/rc
Funding: None.
Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://jtd.amegroups.com/article/view/10.21037/jtd-2026-1579/coif). F.L. reports advisory boards, consulting, and speaker activities for Johnson & Johnson, Daiichi Sankyo, Novocure, Roche, Bristol Myers Squibb (BMS), and AstraZeneca; and travel support from Johnson & Johnson. The other authors have no conflicts of interest to declare.
Data Sharing Statement
Available at https://jtd.amegroups.com/article/view/10.21037/jtd-2026-1579/dss
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