Early source control with non-intubated uniportal video-assisted thoracoscopic surgery for acute thoracic empyema: a retrospective pilot cohort study

Introduction

Background

Initial management of acute thoracic empyema includes appropriate antibiotic therapy and adequate drainage of infected pleural fluid and debris from the empyema cavity (1-4). When these measures are insufficient, timely surgical intervention becomes necessary (1-7). Although tube drainage is the least invasive option, approximately 24–44% of patients ultimately require surgical treatment (6,8,9), and the evidence supporting fibrinolytic therapy remains limited (1,10,11). Video-assisted thoracoscopic surgery (VATS) is currently considered the preferred approach for stage II empyema (12,13) and is recommended early in the treatment course (14). In addition, non-intubated VATS has been reported as a safe, feasible, and minimally invasive approach for managing pleural disease and effusion (15,16).

Rationale and knowledge gap

At Kyoto Yamashiro Medical Center, non-intubated uniportal VATS (NI-uVATS) was introduced as an early treatment strategy following a case in which thoracentesis was unsuccessful. Direct thoracoscopic access to the pleural space enabled immediate visualization, debridement, and lavage, with a favorable postoperative course. This experience suggested that an upfront NI-uVATS approach may be feasible in selected patients and prompted its broader application in subsequent cases.

However, the role of NI-uVATS in the treatment sequence for acute thoracic empyema remains unclear. In particular, it is uncertain whether NI-uVATS should be reserved for cases in which tube drainage fails or whether it can be considered earlier as a source-control strategy in selected patients. When performed without prior tube drainage, NI-uVATS may allow early minimally invasive thoracoscopic debridement and lavage, together with direct assessment of the pleural cavity.

Objective

In this study, we evaluated the clinical outcomes of NI-uVATS for acute thoracic empyema when performed either as the initial procedure or after prior chest drainage. We present this article in accordance with the STROBE reporting checklist (available at https://jtd.amegroups.com/article/view/10.21037/jtd-2026-0940/rc).

Methods

Ethical statement

The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. This study was approved by the Ethics Committee of Kyoto Yamashiro Medical Center on September 26, 2024 (approval No. 2024-33). Because the data were retrospectively collected from an institutional registry, the requirement for informed consent was waived.

Patients

Between July 2019 and June 2025, 51 patients were diagnosed with acute thoracic empyema. Diagnosis was based on clinical history, laboratory findings, chest radiography, computed tomography (CT), and ultrasonography. Of these, 10 patients were excluded: seven with stage II (fibrinopurulent phase) or stage III (organizing phase) disease who underwent conventional VATS; two with stage I (exudative phase) disease who were successfully treated with antibiotics and chest tube drainage; and one who was discharged with a chest tube in place after unsuccessful antibiotic therapy and pleural drainage (Figure 1). Consequently, 41 patients were included in the analysis. Empyema stage was assessed intraoperatively. Stage III was defined as organizing changes involving an estimated >25% of the pleural cavity on intraoperative visual assessment.

Figure 1 Patient selection flow diagram of the study cohort. NI-uVATS, non-intubated uniportal video-assisted thoracoscopic surgery.

Because empyema stage was determined intraoperatively, precise preoperative discrimination among stages I, II, and III disease was not always possible. The one patient classified intraoperatively as stage I in the initial NI-uVATS group was undergoing chemotherapy for advanced lung cancer and presented with fever and pleural effusion. Preoperative ultrasonography showed mild septation, and small pleural nodules suspicious for pleural dissemination were also present. Therefore, NI-uVATS was performed for both pleural source control and direct thoracoscopic assessment. This case differed from the two excluded stage I patients with echo-free pleural spaces who improved with antibiotics and chest tube drainage alone.

During the study period, the selection of NI-uVATS or conventional VATS was based on the surgeon’s judgment, taking into account the clinical course, imaging findings, ultrasonographic findings, and the expected extent of pleural organization. Formal written inclusion and exclusion criteria for NI-uVATS had not been established at the beginning of the study period, because NI-uVATS was gradually introduced into clinical practice at Kyoto Yamashiro Medical Center. In the early phase of this transition, conventional VATS under general anesthesia was selected for some patients, particularly those who underwent surgery after prior chest drainage. After NI-uVATS became routinely adopted, it was generally considered for patients requiring surgical source control when the empyema cavity was expected to be accessible through a uniportal approach under spontaneous breathing. Conventional VATS under general anesthesia was selected when advanced organizing stage III empyema was strongly suspected based on the clinical course and imaging findings and when extensive decortication or a more controlled operative field under general anesthesia was considered necessary.

Anesthesia

Local anesthesia was administered using lidocaine, and sedation was maintained with dexmedetomidine, midazolam, and sevoflurane. Analgesia was achieved with buprenorphine and pentazocine. Intraoperative monitoring included electrocardiography, non-invasive blood pressure, oxygen saturation, and end-tidal carbon dioxide. During NI-uVATS, sedation and intraoperative monitoring were performed by trained operating room nurses. A dedicated anesthesiologist did not remain continuously in the operating room for each case; however, anesthesiologists supervised the operating room suite and were available as backup for airway intervention or conversion to general anesthesia. The nurses continuously observed the monitor, including oxygen saturation, respiratory status, heart rate, blood pressure, and electrocardiography, and assessed the patient’s level of consciousness every 5–10 minutes. Any abnormal findings were immediately reported to the operating surgeon. Airway management equipment and the setup for endotracheal intubation were prepared before the start of surgery.

Surgical procedure

Patients were placed in the lateral decubitus position, and the empyema cavity was localized using ultrasonography. A 3–4 cm uniportal access incision was created, through which a rigid 10-mm, 30° thoracoscope and endoscopic instruments were introduced using a wound retractor. Pleural fluid was collected for Gram staining, microbiological culture, and biochemical analysis. The entire empyema cavity, including the apical portion, was explored using long thoracoscopic instruments. Septations within the empyema cavity were disrupted, and thickened pleura was excised to create a single pleural space. Pulsatile irrigation was performed using a large volume (>6 L) of warm saline (Pulsavac Plus System; Zimmer Biomet, Warsaw, IN, USA) to eliminate residual effusion and organized pus. A 24-Fr chest tube was then placed, and the incision was closed. In selected cases, an additional chest tube was placed when broader drainage of the apical and supradiaphragmatic spaces was considered necessary based on intraoperative findings.

When a fistula was identified intraoperatively, it was considered secondary to rupture of a pulmonary abscess, and additional procedures were performed. In cases of air leak associated with a fistula, the lung was gently compressed to evacuate the purulent material. Because the surrounding tissue was typically friable, primary suture closure was avoided. As the abscess cavity could not be directly visualized, a thin catheter was inserted approximately 5 mm through the fistula, and approximately 1 mL of fibrin glue was injected into the presumed intraparenchymal abscess cavity. This was followed by topical application of fibrin glue to the lung surface and around the fistula to seal the air leak.

Postoperative management

Postoperative antibiotic therapy was initiated based on the intraoperative Gram stain results of pleural effusion obtained during NI-uVATS and was subsequently adjusted according to culture and susceptibility results as needed. Chest tube removal was determined based on postoperative findings (cessation of air leak and clear drainage fluid with an output <100 mL/24 h), microbiological results (negative culture of drainage fluid), and clinical parameters (decreased C-reactive protein levels and white blood cell counts). Antibiotic therapy was continued while the chest tube remained in place and for ≥5 days after its removal.

Statistical analysis

Statistical analyses were performed using Microsoft Excel (Microsoft, Redmond, WA, USA) and EZR software (Jichi Medical University, Saitama, Japan). Continuous variables are presented as medians with interquartile ranges, and categorical variables are presented as numbers and percentages. Continuous variables were compared using the Mann-Whitney U test, and categorical variables were compared using Fisher’s exact test. All tests were two-sided, and P<0.05 were considered statistically significant.

Results

Baseline patient characteristics are summarized in Table 1. NI-uVATS was performed as the initial procedure in 32 patients (initial group) and after prior chest drainage in 9 patients (post-drainage group). Patients in the post-drainage group were referred to the Department of Thoracic Surgery at Kyoto Yamashiro Medical Center due to an insufficient response to initial antibiotic therapy and chest drainage.

Procedure-related outcomes are summarized in Table 2. Operative time was significantly shorter in the initial group than in the post-drainage group (P=0.02). No significant differences were observed between the groups in postoperative drainage duration, total drainage duration, or postoperative hospital stay.

All procedures in the initial group were completed through the uniportal approach without conversion to thoracotomy or general anesthesia. In the post-drainage group, one patient required intraoperative conversion to general anesthesia with endotracheal intubation using a double-lumen tube because excessive sputum caused oxygen saturation to fall below 90%. There were no in-hospital or 6-month deaths. In the initial group, two patients required additional VATS under general anesthesia on postoperative days (PODs) 2 and 7, and one developed recurrent empyema 1 month after discharge.

The intraoperative distribution of empyema stages is shown in Table 2, with most patients classified as stage II or III disease. Fistulous empyema was observed in six patients in the initial group and one patient in the post-drainage group.

Postoperative complications are summarized in Table 3. Pneumonia and air leak occurred only in the initial group, whereas congestive heart failure with acute kidney dysfunction was observed in both groups. Some patients experienced multiple complications.

Microbiological findings are summarized in Table 4. Pleural fluid cultures on POD 1 were negative in 29 of 32 patients (90.6%) in the initial group and in all 9 patients (100%) in the post-drainage group, with no significant difference between the groups (P>0.99). The median time to the first postoperative negative culture was 1 day (interquartile range, 1–1; range, 1–11) in the initial group and 1 day (interquartile range, 1–1; range, 1–1) in the post-drainage group (P=0.36).

Discussion

Key findings

In this retrospective pilot cohort study, we evaluated the clinical outcomes of NI-uVATS for acute thoracic empyema. The main findings were as follows: NI-uVATS was completed without conversion to thoracotomy in all patients, and no in-hospital or 6-month mortality was observed. The initial NI-uVATS group had a shorter operative time than the post-drainage NI-uVATS group, whereas postoperative drainage duration, total drainage duration, and postoperative hospital stay did not significantly differ between the groups. However, one patient required intraoperative conversion to general anesthesia with endotracheal intubation, and two patients required additional surgery under general anesthesia. Therefore, these findings should be interpreted cautiously and suggest that NI-uVATS may serve as a potential early source-control strategy for selected patients, rather than as a universally applicable approach.

Perioperative safety and airway management

Readiness for airway intervention is essential when performing NI-uVATS. In the patient who required intraoperative conversion to general anesthesia and endotracheal intubation, the uniportal incision was temporarily closed with a chest tube left in place. The patient was then turned from the lateral decubitus position to the supine position, and mask ventilation was initiated, followed by endotracheal intubation. This experience highlights that NI-uVATS should be performed only in an operating room setting where close monitoring, immediate communication with the surgical team, and prompt anesthesiology support for airway intervention are available.

Postoperative pneumonia occurred in five patients in the initial NI-uVATS group, two of whom required postoperative intubation. One patient was 95 years old with an Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 3 and developed hypoxemia on postoperative day 10, which was considered to reflect worsening of ipsilateral pneumonia associated with impaired sputum expectoration. The other patient was 91 years old with an ECOG PS of 4 and developed hypoxemia on postoperative day 4; impaired swallowing and postoperative aspiration of saliva or secretions may have contributed to the pneumonia. Both patients were successfully weaned from ventilatory support. No intraoperative aspiration event or sedation-related hypoventilation was documented. Thus, we did not find evidence that these events were directly caused by non-intubated intraoperative management, although a possible contribution cannot be completely excluded given the retrospective design and frailty of the cohort.

Comparison with existing surgical approaches

The single-port strategy used in this study should not be interpreted as a replacement for two-port or multiport VATS. Fujimoto et al. (17) recently reported a favorable outcome after two-port VATS decortication in an 85-year-old high-risk patient with stage II acute empyema and a high RAPID (Renal, Age, Purulence, Infection source, Dietary factors) score after ineffective antibiotic therapy and thoracic drainage. Their report highlights the potential value of two-port VATS in achieving reliable debridement and drainage in selected high-risk patients. At Kyoto Yamashiro Medical Center, the uniportal approach allowed sufficient debridement up to the apical portion of the pleural cavity using long thoracoscopic instruments. However, we agree that two-port VATS and/or placement of multiple drains may be advantageous in patients with complex empyema configurations, such as dependent residual spaces, extensive multiloculation, thick organized pleura, or cavities that cannot be adequately accessed or drained from a single incision. Because predefined criteria for additional drain placement were not established in this retrospective cohort, the optimal drainage strategy remains an important issue for future study. Therefore, our uniportal approach should be considered one possible early source-control strategy for selected patients, and the surgical approach and drainage strategy should be individualized according to the empyema configuration, expected drainage route, microbiological findings, and the need for secure operative exposure.

VATS is widely accepted as an effective surgical approach, particularly for stage II empyema, and is recommended when medical management is inadequate (1-7,12-14,18-20). Beyond its minimally invasive nature, NI-uVATS enables direct thoracoscopic inspection, septal disruption, debridement, and large-volume lavage through a small incision under spontaneous breathing. These interventions directly address a key limitation of tube drainage alone—the persistence of undrainable loculations—by converting a multiloculated pleural space into a single cavity, thereby improving drainage efficiency and facilitating infection control.

The present study should not be interpreted as demonstrating the superiority of NI-uVATS over conventional multiport VATS or other established thoracoscopic approaches. The general concept of non-intubated thoracoscopic management is not new, and the primary goal in acute empyema is adequate source control rather than reducing the number of ports. The clinical contribution of this study lies in describing the institutional experience at Kyoto Yamashiro Medical Center with NI-uVATS as an early source-control strategy in selected patients with acute thoracic empyema, including older and frail patients, and in reporting the selection process, anesthetic management, conversion events, postoperative treatment escalation, and limitations of this approach. Therefore, NI-uVATS should be regarded as one possible option within a broader surgical strategy, rather than as a replacement for conventional VATS.

Timing of intervention and possible explanation of findings

The optimal timing of surgical intervention remains a critical clinical issue in the management of acute thoracic empyema (18-21). In routine practice, antibiotics and tube drainage are typically initiated first, with surgery reserved for cases with an inadequate response. However, delayed intervention may allow further pleural organization and increase procedural complexity. In the present study, operative time was significantly shorter in the initial group than in the post-drainage group, whereas postoperative outcomes were comparable. Although this non-randomized comparison does not establish the superiority of an upfront strategy, it supports the practical feasibility of early NI-uVATS and suggests that prior chest drainage does not necessarily simplify subsequent management once loculation has developed. Given the small number of patients in the post-drainage group, this comparison should be regarded as exploratory and hypothesis-generating.

Preoperative thoracic ultrasonography may aid in identifying loculations and guiding tube placement (22). In our cohort, patients with completely echo-free pleural spaces were managed without surgery, whereas most patients undergoing initial NI-uVATS had septated or multiloculated effusions. In such cases, residual undrainable spaces may persist despite tube placement. Although intrapleural fibrinolytic therapy remains a therapeutic option, its effectiveness is variable in routine clinical practice (1,10,19). These findings support consideration of an early surgical approach in selected patients, as NI-uVATS allows direct septal disruption and thorough pulsatile lavage with a large volume of saline, thereby improving pleural clearance (23).

The marked reduction in pleural fluid culture positivity on POD 1, despite positive intraoperative Gram stains or cultures in many patients, may be partly attributable to the large-volume irrigation performed during NI-uVATS (23). Extensive lavage may reduce bacterial burden and remove infected debris, thereby contributing to early culture negativity. The uniformly negative postoperative cultures in the post-drainage group may have been influenced by preoperative antibiotic exposure and chest drainage during the period of ineffective drainage before referral, in addition to the lavage performed during NI-uVATS. However, these findings should be interpreted with caution, as culture results may be influenced by sampling timing, lavage effects, and early antibiotic administration and do not necessarily indicate complete eradication of infection.

Technical limitations of the procedure

NI-uVATS has several technical limitations. Spontaneous breathing may result in paradoxical or mediastinal movement, potentially narrowing the operative field during inspiration. Inadequate sedation may lead to patient movement, and patients with excessive airway secretions may be at risk of intraoperative airway compromise, as observed in one case requiring endotracheal intubation. In addition, management of intraoperative complications may be more challenging than in procedures performed under general anesthesia.

Strengths and limitations

A strength of this study is that it included a consecutive cohort of patients treated at a single institution and provides detailed descriptions of perioperative management, airway-related events, postoperative treatment escalation, and microbiological outcomes. However, this study has several limitations. First, its retrospective and single-center design introduces potential selection bias and residual confounding, particularly because the choice between initial and post-drainage NI-uVATS was not randomized and because formal prospective criteria for selecting NI-uVATS versus conventional VATS were not established during the early phase of the study period. Second, the small sample size, particularly in the post-drainage NI-uVATS group, limits statistical power and the robustness of between-group comparisons. Therefore, the present findings should be interpreted as exploratory and hypothesis-generating rather than confirmatory. Third, the absence of a control group treated with chest drainage alone or with conventional VATS under general anesthesia precludes direct comparative assessment. Fourth, generalizability may be limited, as outcomes may depend on institutional expertise with specific anesthetic protocols and the uniportal technique. Finally, the relatively short follow-up period limits assessment of long-term outcomes, including late recurrence, functional recovery, and late mortality.

Conclusions

NI-uVATS may be a feasible early source-control option for selected patients with acute thoracic empyema, particularly those with septated or multiloculated effusions in whom chest drainage alone is unlikely to be sufficient. However, because this was a retrospective pilot cohort study with a small post-drainage group, and because treatment-escalation events occurred in some patients, these findings should be interpreted as exploratory and require validation in larger comparative studies before broader clinical implementation.

Acknowledgments

The authors thank Editage for English-language editing. The authors also used ChatGPT (OpenAI; San Francisco, CA, USA) to assist with English-language editing and refinement of the manuscript. The study concept, design, data analysis, interpretation, and final content were determined by the authors, who take full responsibility for the manuscript. Part of this work was presented at the 39th EACTS Annual Meeting, Copenhagen, Denmark, October 8–11, 2025.

Footnote

Reporting Checklist: The authors have completed the STROBE reporting checklist. Available at https://jtd.amegroups.com/article/view/10.21037/jtd-2026-0940/rc

Data Sharing Statement: Available at https://jtd.amegroups.com/article/view/10.21037/jtd-2026-0940/dss

Peer Review File: Available at https://jtd.amegroups.com/article/view/10.21037/jtd-2026-0940/prf

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-2026-0940/coif). All authors report that the article processing charge for this manuscript was partially supported by Kyoto Yamashiro Medical Center, Kizugawa, Kyoto, Japan. The authors have no other 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 was approved by the Ethics Committee of Kyoto Yamashiro Medical Center (approval No. 2024-33; September 26, 2024). Because the data were retrospectively collected from an institutional registry, the requirement for informed consent 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/.

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