Recommendations for the standardization and management of prolonged air leaks in lung surgery

Abstract

Background

Prolonged air leaks (PAL) are a common postoperative complication following lung surgery, associated with increased morbidity, extended hospital stays, and heightened healthcare costs. The incidence of air leaks ranges from 20 to 33%, with PAL occurring in 6%–26% of cases. Management strategies for PAL remain inconsistent, highlighting the need for standardized guidelines to address this issue.

This study employed the GRADE approach to develop consensus-based recommendations for detecting and managing post-lung surgery PAL.

Methods

A task force of 18 thoracic surgeons, including a methodologist, conducted a systematic literature review focusing on 14 critical clinical questions. Recommendations were developed based on evidence from meta-analyses, randomized controlled trials, and observational studies, and graded according to the quality of evidence and the strength of the recommendation.

Results

Thirty-five studies were included in the final analysis. The consensus highlighted the lack of standardization in defining PAL and emphasized the need for personalized management based on clinical context. Key recommendations included the use of reinforced staples, parenchymal sutures, and sealants in high-risk patients, the preference for digital drainage systems, and the management of confirmed PALs with strategies such as chemical pleurodesis and surgical exploration.

Conclusions

The consensus underscores the importance of a multidisciplinary approach in managing PAL, the need for standardizing definitions, and the ongoing requirement for evidence-based guidelines to improve patient outcomes. Future research should focus on addressing the limitations identified in this study.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40001-025-03529-9.

Introduction

Prolonged air leaks (PAL) are a significant postoperative complication that can arise following lung surgery, particularly after procedures, such as lobectomies or other forms of pulmonary resection. Defined as an air leak persisting for more than five days, PAL can lead to various adverse outcomes, including increased morbidity, extended hospital stays, and heightened healthcare costs. The incidence of air leaks after lung surgery ranges from 20 to 33%, with prolonged air leaks occurring in approximately 6% to 26% of cases, depending on various factors such as surgical technique, patient characteristics, and underlying lung disease [1, 2]. The pathophysiology of PAL is complex and can be attributed to several factors, including the formation of alveolar-pleural fistulas, which can occur due to inadequate sealing of the lung parenchyma during surgery. In addition, patient-specific factors, such as age, sex, body mass index (BMI), and preoperative lung function (measured by forced expiratory volume in one second, FEV1) have been identified as potential risk factors for the development of PAL. Studies have shown that older patients, males, and those with lower lung function are at a higher risk of experiencing PAL. The management of PAL poses a challenge for clinicians, as it often requires a multidisciplinary approach involving both thoracic surgeons and pulmonologists. Initial treatment typically includes “wait and see” management. However, in case of failure, more invasive interventions such as pleurodesis, bronchoscopic techniques, or surgical re-exploration may be necessary. Identifying intraoperative risk factors and quantifying air leaks during surgery is critical for developing effective strategies to prevent and manage PAL. Despite the prevalence and impact of PAL, there remains a need for greater consensus regarding its definition and management protocols. Some studies define PAL as an air leak lasting longer than five days, while others use a seven-day threshold. This variability complicates the comparison of outcomes across studies and highlights the need for standardized definitions and treatment guidelines. Recent advancements in technology, such as digital monitoring devices, have shown promise in improving the management of air leaks by providing real-time data on the presence and severity of leaks. Continuous monitoring enables clinicians to distinguish between active air leaks and pleural space effects, informing treatment decisions and potentially reducing the duration of hospital stays.

To enhance understanding of the dynamic management of patients with PAL, we initiated a modified Delphi process that reached an agreement on issues regarding the detection and management of PAL [1]. Without prospective, randomized evidence supporting most of these clinical decisions, this collaborative effort aimed to develop recommendations to reduce practice variation in the management of PAL according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach [3]. This consensus represents the first systematic application of the GRADE methodology to PAL management in thoracic surgery. By grading the certainty of evidence and the strength of recommendations across multiple clinical scenarios, this document aims to standardize heterogeneous practices and provide a reproducible, evidence-based framework for clinical decision-making. The integration of digital monitoring, artificial intelligence–based prediction models, and ERAS pathways will further refine PAL prevention and management. This consensus should thus be viewed as both a methodological reference and a platform for future innovation in thoracic surgery.

Materials and methods

In January 2022, a task force comprising 18 thoracic surgeons was convened, with one thoracic surgeon serving as the methodologist (LB). Through a virtual meeting, this team developed a draft of recommendations following the patient, intervention, comparator, outcome (PICO) format, which outlines Population, Intervention, Comparison, and Outcome. Two coordinators were appointed to manage the recommendations (LB, FZ). The acknowledgments provide a list of the group members and their responsibilities. Each member’s conflicts of interest (COI) were recorded transparently. The industry was not involved. The protocol, including critical questions and a timeline, was approved by the participants.

The GRADE approach was used to formulate the recommendations [4–7]. The coordinators proposed vital questions, which were revised and approved by the group. Although specific questions may appear conceptually overlapping (e.g., VATS vs. open procedures), the separation followed the GRADE-PICO framework, which requires distinct evidence appraisal for each clinical context to ensure transparency and methodological rigor. The group was divided into teams working on specific vital questions. Each team decided on essential outcomes of critical questions using the PICO approach. A systematic literature review was performed for each key question. If up-to-date, high-quality meta-analyses or systematic reviews were available, the conclusions were derived from these; the next level in quality was randomized controlled trials (RCT) and observational studies. Case series were included only if they added substantial evidence/information or if no higher level of evidence was available. Case reports and expert opinions were not included. A grey literature search was also conducted, supplemented by knowledge of conference proceedings from expert writing group members. Bibliographies of relevant studies were also examined. The search was confined to English-language studies.

Two reviewers independently conducted a systematic literature search, reporting on 1 May 2022, and updated it on 1 February 2023. The Cochrane Library, PubMed, Embase, CINAHL, and Google Scholar were searched using Medical Subject Headings (MeSH) terms. PICO questions were available in Supplemental File 1. Search terms for each subject are available in Supplemental File 2. Records were screened by title and abstract by two assessors. Full texts were independently evaluated by two assessors. Only papers rated as acceptable or high quality according to the GRADE checklist were included to limit the risk of bias. Any disagreements between assessors were settled through discussion within the entire group or by a third assessor. In addition to the qualitative GRADE assessment, a quantitative summary of the methodological quality and risk of bias was performed for all included studies using the GRADE checklist domains. The results of this evaluation are reported in Supplementary Table 3, which provides the study design, sample size, main topic, and corresponding risk-of-bias grading. The study identification, screening, and inclusion process are summarized in a PRISMA 2020 flow diagram (Fig. 1).

Fig. 1.

PRISMA 2020 flow diagram of study selection

Each subgroup then utilized synthesized data to formulate evidence-based recommendation statements. Following guidance from the GRADE approaches, each subgroup deliberated on and assigned the quality of evidence and level of recommendation (Table 1)

Table 1.

Diagnostic and treatment questions for managing intraoperative and postoperative air leaks in lung resections

1	Should a Prolonged Air Leak (PAL) be defined as postoperative air leaks that prolong the average hospital stay vs if they last more than five days?
2	Should a submersion test (bubbling test) vs a ventilator test be used to diagnose IAALs in VATS anatomical resections?
3	Should a submersion test (bubbling test) vs a ventilator test be used to diagnose IAALs in open anatomical resections?
4	Should treatment vs “wait-and-see” attitude be used for intraoperative IALLs detected at submersion test?
5	Should reinforced (buttressed) staples be used to divide lung parenchyma for patients with COPD undergoing anatomical lung resection?
6	Should parenchymal suturing vs sealants be used to treat IALLs in VATS lung resections?
7	Should a 24 Fr vs a 28 Fr chest tube drainage be used in anatomical resections?
8	Should digital and traditional drainages be used to evaluate postoperative air leaks?
9	Should water seal only vs suction be used in the postoperative period after anatomical lung resections?
10	Should suction vs water seal only be used in case of empty space?
11	Should suction vs water seal only be used in case of moderate/severe air leaks?
12	Should a water seal vs Heimlich valve be used in case of persistent (> five days) mild air leak?
13	Should chemical pleurodesis versus surgical exploration be performed with a prolonged postoperative air leak > 5 days following anatomical lung resection?
14	In the case of PAL, should we discharge the patient vs continue hospitalisation?

Results

Fourteen key questions were formulated, and thirty-five studies were ultimately included (Fig. 1). The methodological quality of these studies and the corresponding risk-of-bias assessment are summarized in Supplementary Table 3. The key questions and recommendations are synthesized in Table 2.

Table 2.

Recommendations for managing prolonged air leaks in lung surgery

Question	Recommendation
1. Should a Prolonged Air Leak (PAL) be defined as postoperative air leaks that prolong the average hospital stay vs if they last more than five days?	Consider a dual-definition approach, using both average hospital stay and a fixed duration (> 5 days)
2. Should a submersion test (bubbling test) vs a ventilator test be used to diagnose IAALs in VATS anatomical resections?	Prioritize ventilator tests for objective quantification, but submersion tests may supplement as needed
3. Should a submersion test (bubbling test) vs a ventilator test be used to diagnose IAALs in open anatomical resections?	Use ventilator tests primarily, with submersion tests for additional visual confirmation
4. Should treatment vs “wait-and-see” attitude be used for intraoperative IALLs detected at submersion test?	Adopt “wait-and-see” for mild leaks, treat moderate leaks selectively, and severe leaks immediately
5. Should reinforced (buttressed) staples be used to divide lung parenchyma for patients with COPD undergoing anatomical lung resection?	Use reinforced staples selectively, guided by patient condition and surgeon preference
6. Should parenchymal suturing vs sealants be used to treat IALLs in VATS lung resections?	Base the choice on the severity of the leak; combine sutures and sealants as needed for optimal outcomes
7. Should a 24 Fr vs a 28 Fr chest tube drainage be used in anatomical resections?	Choose tube size based on patient needs; 28 Fr for extensive drainage, 24 Fr for comfort in less critical cases
8. Should digital and traditional drainages be used to evaluate postoperative air leaks?	Opt for digital drainage systems due to their accuracy, reduced variability, and better outcomes
9. Should water seal only vs suction be used in the postoperative period after anatomical lung resections?	Prefer water seals for most cases to minimize prolonged air leaks, considering suction selectively
10. Should suction vs water seal only be used in case of empty space?	Tailor the use of suction or water seal to the presence of residual space and patient needs
11. Should suction vs water seal only be used in case of moderate/severe air leaks?	Use suction for moderate/severe leaks; consider water seals for mild leaks to prevent further air leaks
12. Should a water seal vs Heimlich valve be used in case of persistent (> 5 days) mild air leak?	Use Heimlich valves for stable patients; opt for water seals for closer monitoring in unstable cases
13. Should chemical pleurodesis versus surgical exploration be performed with a prolonged postoperative air leak > 5 days following anatomical lung resection?	Start with chemical pleurodesis for prolonged leaks; escalate to surgical exploration if needed
14. In the case of PAL, should we discharge the patient vs continue hospitalisation?	Discharge stable patients with proper follow-up; hospitalize if significant complications or instability persist

Should a prolonged air leak be defined as postoperative air leaks that prolong the average hospital stay, or if they last more than 5 days?

The definition of a PAL varies across studies, with some researchers defining it as an air leak that lasts beyond the average postoperative hospitalization time. In contrast, others use a specific duration of more than 5 days. The definition of the Average Hospital Stay considers the typical length of stay for patients undergoing similar procedures. It defines PAL as any air leak that extends beyond the average length of stay. This definition can be more flexible and may account for variations in patient recovery times and surgical techniques. Defining PAL as an air leak lasting more than 5 days provides a clear and measurable criterion for diagnosis. This definition is commonly used in clinical studies, facilitating comparisons across research findings. However, it may need to account for individual patient circumstances or variations in surgical practices. Both definitions have their merits. The choice between them may depend on the study’s specific context or clinical practice. Some studies have shown that prolonged air leaks can significantly impact hospital costs and patient outcomes, regardless of the definition. Therefore, it may be beneficial to consider both the average hospital stay and a fixed duration when assessing PAL in clinical settings [2, 8].

Recommendation: A dual-definition approach is recommended to manage PAL effectively after lung surgery. When defining PAL, clinicians should consider the average postoperative hospital stay and a fixed duration of more than 5 days. This comprehensive strategy allows for flexibility in patient management while providing clear criteria for identifying prolonged air leaks. In addition, continuous monitoring techniques can help distinguish between active air leaks and pleural space effects, ultimately improving patient outcomes and reducing hospital costs associated with prolonged stays.

Quality of evidence:

Strength of recommendation: Weak.

Should a submersion test (bubbling test) vs a ventilator test be used to diagnose intraoperative air leaks in vats anatomical resections?

The choice between using a submersion test (bubbling test) and a ventilator test to diagnose intraoperative air leaks (IAALs) in video-assisted thoracic surgery (VATS) anatomical resections appears to depend on several factors, including the reliability and objectivity of the tests. The submersion test is commonly used and involves submerging the lung in saline to observe for bubbling, which indicates an air leak. However, it has limitations, particularly regarding visibility and exposure after lung reinflation, which can make it difficult to obtain reliable evaluations in some cases, especially during VATS procedures. The ventilator or mechanical ventilation test (MVT) measures the difference between the expired tidal volume and the inspiratory tidal volume to assess air leaks. This method is considered more objective and standardized than the bubbling test. It enables the quantification of air leaks, which can be classified as mild, moderate, or severe based on specific thresholds. While both tests have their uses, the ventilator test may provide a more reliable and objective assessment of IAALs during VATS anatomical resections. The bubbling test may still be used, but its subjective nature and potential for unreliable results in certain situations could limit its effectiveness. Therefore, combining both methods or preferring the ventilator test might be advisable in clinical practice [1, 9–12].

Recommendation: When assessing IAALs during VATS anatomical resections, it is recommended to prioritize the use of the MVT over the submersion (bubbling test). The ventilator test provides a more objective and standardized approach to quantifying air leaks, enabling precise classification into mild, moderate, or severe categories based on specific thresholds. Although the submersion test can still be utilized, its subjective nature and potential limitations in visibility and reliability, particularly after lung reinflation, may hinder accurate evaluations in some instances. Therefore, employing the ventilator test as the primary diagnostic tool, supplemented by the submersion test when necessary, is advised to ensure a comprehensive and reliable assessment of IAALs in VATS procedures.

Quality of evidence:

Strength of recommendation: Weak.

Should a submersion test (bubbling test) vs a ventilator test be used to diagnose iaals in open anatomical resections?

The choice between using a submersion test (bubbling test) and a ventilator test for diagnosing IAALs in open anatomical resections depends on several factors, including the specific clinical context and the surgical team’s preferences. The submersion test is often used to visually assess the presence and degree of air leaks during surgery. It involves submerging the resected lung in water and observing for bubbling, which indicates an air leak. Although this method is straightforward and provides immediate visual feedback, it can be subjective. It may only sometimes offer a reliable assessment, especially in cases where visibility is compromised (e.g., during VATS). Ventilator Testing involves assessing intraoperative air leaks by measuring the difference between expired and inhaled tidal volumes during mechanical ventilation. It can provide a more objective measurement of air leaks and may be particularly useful in cases where the bubbling test is not feasible or reliable. The literature recognizes that while the bubbling score can indicate the presence of an air leak, it is not consistently considered a predictor of prolonged air leak postoperatively. Many studies have suggested that the ventilator test may provide a more standardized and objective assessment of air leaks, which could be beneficial in guiding intraoperative management decisions. Ultimately, the decision on which test to use may depend on the surgical team’s experience, the specific circumstances of the surgery, and the need for objective measurements. Combining both tests may also enhance diagnostic accuracy [12].

Recommendation: In diagnosing IAALs during open anatomical resections, it is recommended to utilize the ventilator test as a primary method for assessing air leaks. This approach provides a more objective and quantitative measurement of air leakage compared to the submersion (bubbling test), which can be subjective and influenced by visibility issues during surgery. Although the submersion test may still be employed for its immediate visual feedback, reliance solely on this method is discouraged due to its limitations in predicting prolonged air leaks postoperatively. Therefore, a combined approach incorporating both the ventilator test for objective assessment and the submersion test for visual confirmation may enhance diagnostic accuracy and inform intraoperative management decisions. Surgeons should be trained in both techniques and consider the specific clinical context to determine the most appropriate method for each case.

Quality of evidence:

Strength of recommendation: Weak.

Should treatment vs. “wait-and-see” attitude be used for intraoperative ialls detected at submersion test?

The approach to treating IAALs detected during a submersion test varies among experts. According to the consensus reached in recent studies, treating IAALs detected at the submersion test is often recommended, particularly for patients at high risk for cardiopulmonary complications. Sixty-eight percent of experts indicated that they would treat IAALs in high-risk patients if detected during the submersion test. However, for mild IAALs, many experts believe they are self-limiting and do not require treatment. In contrast, the consensus on moderate IAALs could be more precise, with opinions divided on whether to treat all patients or only high-risk ones. In summary, while there is a tendency to treat IALs in high-risk patients, a “wait-and-see” approach may be considered for mild cases, reflecting a lack of consensus on the best management strategy for moderate IAALs [1].

Recommendation: Recommendation for Management of IAALs Detected at Submersion Test:

• Mild IAAL (< 100 ml/min): It is recommended to adopt a cautious “wait-and-see” approach only in stable, low-risk patients, as these minor leaks are often self-limiting. Continuous intraoperative monitoring and postoperative reassessment are mandatory to avoid under-treatment.

• Moderate IAAL (100–400 ml/min): Treatment for cardiopulmonary complications is recommended for high-risk patients. For other patients, a case-by-case assessment should be made, considering the patient’s overall condition and the potential for progression to a prolonged air leak.

• Severe IAAL (> 400 ml/min): Immediate treatment is highly recommended, as these leaks are associated with a higher risk of complications and prolonged air leaks.

Quality of evidence:

Strength of recommendation: Weak.

Should reinforced (buttressed) staples be used to divide lung parenchyma for patients with copd undergoing anatomical lung resection?

The use of reinforced (buttressed) staples in lung parenchyma division for patients with COPD undergoing anatomical lung resection has been evaluated in several studies, but the results are mixed. In a multicenter RCT, fissure opening staple-line reinforcement with alginate was used compared to standard stapling without reinforcement. The study found no significant difference in air leak duration between the two groups, suggesting that the buttressing did not provide a clear advantage in reducing air leaks after pulmonary lobectomy. Other studies have also explored the effectiveness of different buttressing materials and found no significant differences in outcomes related to air leaks. Although the intention behind using buttressed staples is to reduce air leaks and potentially shorten hospital stays, current evidence does not strongly support their routine use over standard stapling techniques in patients with COPD undergoing anatomical lung resection. Therefore, the decision to use reinforced staples should be made on a case-by-case basis, taking into account the specific clinical scenario and the surgeon’s preference. In summary, the current literature does not provide a definitive recommendation for the routine use of buttressed staples in this context, and further research may be needed to clarify their role [13].

Recommendation: Based on the current evidence regarding using reinforced (buttressed) staples for dividing lung parenchyma in patients with COPD undergoing anatomical lung resection. The decision to use buttressed staples should be individualized based on the patient’s specific clinical condition, the extent of lung disease, and the surgeon’s experience and preference. Given the lack of significant evidence supporting the superiority of buttressed staples over standard stapling techniques in reducing air leaks, standard stapling methods may be sufficient for most patients. Surgeons should consider using non-buttressed staplers, especially in cases where the risk of air leaks is low. If buttressed staples are used, it is essential to monitor postoperative outcomes, particularly the incidence and duration of air leaks, to gather data that may inform future practice and contribute to the ongoing evaluation of this technique. Encourage participation in or support further research to understand better the benefits and drawbacks of buttressed versus non-buttressed stapling techniques in this patient population, particularly concerning long-term outcomes and quality of life. By following these recommendations, clinicians can make informed decisions that optimize patient care while considering the current limitations of the evidence.

Quality of evidence:

Strength of recommendation: Weak.

Should parenchymal suturing vs sealants be used to treat ialls in vats lung resections?

The choice between parenchymal suturing and sealants for treating IAALs during VATS lung resections is a topic of ongoing debate in the surgical community. Parenchymal Suturing involves suturing the areas of air leakage. It is often preferred for its direct approach to sealing leaks. However, it can be technically challenging and time-consuming, especially in the minimally invasive setting of VATS. Surgical sealants have gained popularity due to their ease of application and ability to seal leaks quickly without the need for suturing. Studies have shown that sealants can reduce the incidence of PAL and the time to chest drain removal, although results regarding their impact on length of stay and overall effectiveness are mixed. Some studies suggest that sealants may not provide significant benefits in preventing PAL as compared to suturing, particularly in high-risk patients. Although both methods have advantages, the decision may depend on the specific clinical context, the surgeon’s experience, and the characteristics of the air leak. A combination of both techniques may also be considered to optimize outcomes. Further research and consensus are needed to establish clear guidelines on the best approach for managing IAALs in VATS lung resections [1, 14, 15].

Recommendation: It is recommended that the severity of the intraoperative air leak be assessed before treatment using standardized grading systems. This evaluation will guide the selection of the most appropriate management strategy. Treatment choice should also be tailored based on individual patient risk factors, including overall health, lung function, and the complexity of the surgical procedure, as high-risk patients may require a more aggressive approach. Surgical sealants should be considered a viable option for managing moderate IAALs, particularly in cases where suturing may be technically difficult or time-consuming. Sealants can provide rapid closure and may reduce the incidence of prolonged air leaks. However, parenchymal suturing remains critical for significant or persistent air leaks. It is recommended for larger leaks or when a more definitive closure is necessary, as it provides a direct and reliable sealing method. In moderate to severe IAAL cases, a combination of both parenchymal suturing and sealants may be beneficial. This dual approach can leverage the strengths of both methods, enhancing the likelihood of successful air leak closure. Finally, support and participation in further research comparing the effectiveness of parenchymal suturing versus sealants in various clinical scenarios is encouraged. This will contribute to the development of evidence-based guidelines for managing IAALs in VATS lung resections. By following these recommendations, surgical teams can make informed decisions regarding the use of parenchymal suturing and sealants, ultimately improving the management of intraoperative air leaks during VATS lung resections.

Quality of evidence:

Strength of recommendation: Weak.

Should a 24 Fr vs a 28 Fr chest tube drainage be used in anatomical resections?

The choice between a 24 Fr and a 28 Fr chest tube for drainage in anatomical resections can depend on various factors, including the specific surgical procedure, the patient’s condition, and the surgeon’s preference. A 28 Fr chest tube is larger than a 24 Fr tube, which may allow for better drainage of pleural fluid and air. However, larger tubes can also be associated with increased discomfort for the patient and a higher risk of complications such as injury to surrounding tissues. Some studies suggest that the use of a single 28 Fr drain is routine for pulmonary wedge resections. In contrast, two drains (often a combination of 24 Fr and 28 Fr) are typically used after major anatomical resections. This ensures adequate drainage, especially in cases with significant pleural effusion or air leaks. The literature does not provide a definitive consensus on the superiority of one size over the other for all cases. The surgeon’s experience and specific clinical scenario may also influence the choice. For instance, in cases with extensive adhesions or larger resections, a larger tube may be preferred to facilitate drainage. Both 24 Fr and 28 Fr tubes can be used effectively in anatomical resections, and the decision should be tailored to the individual patient’s needs and the surgical context [16, 17].

Recommendation: For most anatomical resections, particularly those involving significant pleural effusion or air leaks, it is recommended that a 28 Fr chest tube be utilized. This size allows for improved drainage and management of postoperative complications. In cases where the patient may be at higher risk for complications related to larger tubes or in less extensive resections, a 24 Fr chest tube may be considered to balance adequate drainage with patient comfort. The final decision on chest tube size should be made at the surgeon’s discretion, taking into account the specific surgical context, the presence of adhesions, and the patient’s overall condition. Regardless of the size chosen, continuous monitoring of the patient’s drainage output and clinical status is essential. The drainage strategy should be adjusted based on the patient’s response and any potential complications that may arise. This recommendation aims to optimize patient outcomes while minimizing discomfort and complications associated with chest tube drainage in anatomical resections.

Quality of evidence:

Strength of recommendation: Weak.

Should digital drainages vs. traditional drainages be used for evaluating postoperative air leaks?

Using digital drainage systems compared to traditional drainage systems for evaluating postoperative air leaks has shown several advantages. Studies indicate that digital drainage systems are associated with a shorter duration of chest tube placement, reduced air leak duration, and shorter hospital stays while potentially lowering postoperative costs. Digital systems provide continuous recording of air leaks, enhancing data collection accuracy and reducing variability caused by subjective physician judgments regarding chest tube removal. They also allow for precise measurement of air leaks, which can help standardize evaluations and minimize inter-observer variability. Moreover, some studies have reported that digital systems lead to fewer prolonged air leaks than traditional systems, suggesting that they may be more effective in managing postoperative complications. In conclusion, the evidence supports the use of digital drainage systems over conventional systems for evaluating postoperative air leaks due to their benefits in accuracy, efficiency, and patient outcomes. However, further studies are needed to explore their roles in high-risk patient subgroups [8, 16, 18, 19].

Recommendation: Based on the available evidence, digital drainage systems should be utilized instead of traditional drainage systems for evaluating postoperative air leaks. Digital systems offer significant advantages, including the ability to continuously record air leaks, which enhances the accuracy of data collection and minimizes variability caused by subjective physician judgments regarding chest tube removal. Studies have demonstrated that the use of digital drainage systems is associated with a shorter duration of chest tube placement, reduced air leak duration, and shorter hospital stays, ultimately leading to lower postoperative costs.

Furthermore, digital systems tend to decrease the incidence of prolonged air leaks, indicating their effectiveness in managing postoperative complications. Therefore, adopting digital drainage systems can improve patient outcomes and streamline the evaluation process for postoperative air leaks. However, further research is essential to understand their impact on high-risk patient populations.

Quality of evidence:

Strength of recommendation: Weak.

Should water seal only vs suction be used in the postoperative period after anatomical lung resections?

The choice between water seal and suction in the postoperative period after anatomical lung resections has been a topic of debate. Several studies have compared these two methods, and the findings suggest that water seals may be associated with a shorter duration of postoperative air leak and chest drainage as compared to continuous suction. Water seals are often recommended for their potential to prevent higher air leak rates through suture lines that might otherwise occur in the absence of negative pressure from suction. This method allows for a more natural re-expansion of the lung without the risk of creating additional air leaks. Proponents of suction argue that it helps restore the intrapleural vacuum, eliminates residual space, and promotes lung expansion more effectively. However, the evidence is mixed, with some studies indicating that suction may not be necessary and could even lead to prolonged air leaks. A recent study demonstrated that water seals were associated with significantly shorter postoperative air leak and chest drainage durations compared to continuous suction and digital drainage systems. Other randomized controlled trials have shown conflicting results, suggesting that the optimal approach may depend on individual patient factors and specific clinical scenarios. While water seals may offer advantages in particular contexts, the decision should be tailored to the individual patient, considering factors such as the extent of the resection, air leaks, and the surgeon’s experience. Further research and consensus guidelines may help clarify best practices in this area [20, 21].

Recommendation: Based on the current evidence regarding postoperative chest drainage after anatomical lung resections, it is recommended that clinicians consider using a water seal as the preferred method over continuous suction in many cases. Studies have shown that water seals are associated with a significantly shorter duration of postoperative air leaks and chest drainage, which may enhance patient recovery and reduce hospital stays. While suction has benefits, particularly in restoring intrapleural vacuum and promoting lung expansion, it may also contribute to prolonged air leaks in some patients. Therefore, the choice between water seal and suction should be individualized, considering the specific clinical scenario, the extent of the lung resection, and the surgeon’s experience. Further research is warranted to establish definitive guidelines; however, current findings suggest that a water seal may be suitable for many patients following lung surgery.

Quality of evidence:

Strength of recommendation: Weak.

Should suction vs water seal only be used in the case of empty space?

The use of suction versus water seal in managing air leaks after pulmonary operations is a topic of ongoing debate. Some studies suggest that suction can help restore intra-pleural vacuum and eliminate residual space, thereby potentially expediting lung expansion. However, others argue that the early use of water seals might prevent higher air leak rates through suture lines that could be sealed without the negative pressure of suction. In practice, the use of suction or a water seal may depend on the specific clinical scenario, including the presence of a residual pleural space. For instance, if there is a significant space, suction might be favoured to help manage that condition. Conversely, if the air leak is manageable, a water seal could be considered to avoid potential complications associated with suction. Ultimately, the choice should be guided by the individual patient’s circumstances and the healthcare provider’s clinical judgment, as there is no one-size-fits-all answer to this question [20, 22].

Recommendation: In managing postoperative air leaks after pulmonary operations, it is recommended that the choice between suction and water seal be tailored to the individual patient’s clinical situation. If there is a significant residual pleural space, using suction may be beneficial in restoring the intrapleural vacuum and facilitating lung expansion. However, in cases where the air leak is manageable, employing a water seal could be advantageous to avoid the potential complications associated with suction, such as increased air-leak rates through suture lines. Ultimately, the decision should be based on the careful clinical assessment and each patient’s specific circumstances, ensuring that the approach aligns with best practices and the latest evidence in the field.

Quality of evidence:

Strength of recommendation: Weak.

Should suction vs water seal only be used in the case of moderate/severe air leaks?

The decision to use suction versus water seal in managing air leaks after pulmonary surgery is often influenced by the severity of the air leak. Studies suggest that suction may be more beneficial in cases of moderate to severe air leaks, as it can help restore the intrapleural vacuum and facilitate lung expansion more effectively. Conversely, a water seal may be preferred in mild air leaks to avoid promoting higher air-leak rates through suture lines that might otherwise seal without the negative pressure of suction. For instance, some studies indicate that a regulated seal can be as effective as regulated suction in managing air leaks, suggesting that the choice may depend on the specific clinical scenario and the surgeon’s preference. In addition, if a water seal fails to resolve the air leak, transitioning to suction or using an ambulatory one-way valve may be considered to reduce hospital length of stay. While suction may be more appropriate for moderate to severe air leaks, the management strategy should be tailored to the patient’s condition and the surgeon’s clinical judgment. Further research and randomized controlled trials are needed to establish more straightforward guidelines [20, 22–24].

Recommendation: When managing air leaks after pulmonary surgery, consider the severity of the air leak when deciding between suction and water seal. Suction may benefit moderate to severe air leaks, as it helps restore the intrapleural vacuum and facilitates lung expansion. Conversely, a water seal may be appropriate for mild air leaks to avoid promoting higher air-leak rates through suture lines that could seal without negative pressure. Ultimately, the choice should be tailored to the individual patient’s condition and guided by the surgeon’s clinical judgment, with further research needed to establish more straightforward guidelines on this management strategy.

Quality of evidence:

Strength of recommendation: Weak.

Should water seal vs heimlich valve be used in case of prolonged (> 5 days) mild air leak?

In persistent mild air leaks lasting more than 5 days, choosing between a water seal and a Heimlich valve can depend on several factors, including the patient’s condition and the clinical setting. A digital drainage system is often used when there are concerns about the severity of the air leak or if the patient is not stable enough for discharge. It enables continuous air leak monitoring and helps manage potential complications. The Heimlich Valve can be used for stable patients who are ready for discharge. It allows for greater mobility and can reduce the length of hospital stay. Studies have shown that many patients with mild air leaks can be safely discharged with a Heimlich valve, and many experience resolution of their leaks at home. Ultimately, the decision should be based on the patient’s circumstances, including the nature of the air leak, potential complications (such as pneumothorax or subcutaneous emphysema), and the overall clinical picture. If the air leak is mild and the patient is stable, a Heimlich valve may be appropriate; otherwise, a water seal may be preferred for closer monitoring [24, 25].

Recommendation: In cases of persistent mild air leaks lasting more than 5 days, it is recommended to consider the patient’s overall clinical condition and stability when deciding between a digital drainage system and a Heimlich valve. If the patient is stable and there are no significant complications, using a Heimlich valve can be appropriate, as it allows for greater mobility and can facilitate a shorter hospital stay. Many patients with mild air leaks have been shown to safely manage their condition at home with a Heimlich valve, often experiencing resolution of the leak. However, if there are concerns regarding the severity of the air leak or if the patient is not stable, a digital system should be utilized to allow for continuous monitoring and management of potential complications. Ultimately, the decision should be tailored to the individual patient’s circumstances, ensuring that the chosen method aligns with their clinical needs and safety.

Quality of evidence:

Strength of recommendation: Weak.

Should chemical pleurodesis versus surgical exploration be performed with a prolonged postoperative air leak > 5 days following anatomical lung resection?

The decision between chemical pleurodesis and surgical exploration for managing a prolonged postoperative air leak (PAL) that has persisted for more than five days following anatomical lung resection depends on various factors, including the patient’s condition, the characteristics of the air leak, and the surgeon’s experience. Chemical Pleurodesis involves instilling a sclerosing agent into the pleural space to promote adhesion between the pleurae, thereby sealing the air leak. It is often considered a less invasive option and can effectively manage PAL. Studies have shown that chemical pleurodesis can benefit persistent air leaks, particularly when the leak is not associated with significant complications in the pleural space. Surgical Exploration may be necessary if the air leak is substantial and complications such as empyema or chemical pleurodesis fail. Surgical exploration enables direct visualization and repair of the source of the leak, which may be more effective in certain instances. If a patient has a PAL for over five days, chemical pleurodesis may be a suitable first-line treatment, especially if the leak is not complicated. However, surgical exploration may be warranted if signs of complications are present or if pleurodesis is unsuccessful. The choice should be individualized based on clinical judgment and the patient’s circumstances [12, 13, 26].

Recommendation: In cases of prolonged PAL (> 5 days) following anatomical lung resection, chemical pleurodesis is recommended as the first-line option only when full or near-complete lung re-expansion is achieved and no pleural infection is present. If these conditions are not met or if pleurodesis fails, surgical exploration should be performed to identify and repair the source of the leak directly.

Quality of evidence:

Strength of recommendation: Weak.

In the case of pal, should we discharge the patient or continue hospitalisation?

The decision to discharge a patient with a PAL or to continue hospitalization depends on several factors, including the patient’s clinical status, the management plan, and the potential risks associated with discharge. Some studies suggest that outpatient management of PAL can be a safe and cost-effective option, especially for patients who meet traditional discharge criteria. Patients can be discharged with a chest tube connected to a one-way valve mechanism, allowing continued monitoring at home. Patients discharged with a chest tube typically require regular follow-up visits to assess the air leak and manage any complications. This can include clinic visits every few days or home care overseen by a thoracic nurse navigator. It is important to note that patients discharged with a chest tube may have higher rates of hospital readmission due to complications such as empyema or the need for further surgical intervention. In one study, 23% of patients discharged with a chest tube required readmission. Continuing hospitalization may be warranted if the patient shows signs of complications or if the air leak is significant and not improving. Prolonged hospitalization can help manage potential pneumonia or other respiratory complications. If the patient is unstable or has other comorbidities that could complicate their recovery, it may be safer to keep them hospitalized until their condition stabilizes. The decision to discharge a patient with PAL should be individualized, considering the patient’s overall health, the severity of the air leak, the presence of any complications, and the availability of follow-up care. It is essential to weigh the benefits of outpatient management against the risks of potential complications that may arise after discharge [27–29].

Recommendation: In managing patients with PAL, it is recommended that the decision to discharge a patient or continue hospitalization be made individually, considering the patient’s overall clinical status and the severity of the air leak. If the patient is stable and meets the criteria for outpatient management, discharge with a chest tube connected to a one-way valve may be appropriate, provided that a robust follow-up care plan is in place. This plan should include regular clinic visits or home care oversight to monitor the air leak and address potential complications. However, if the patient exhibits signs of instability, has significant comorbidities, or the air leak is not improving, it may be prudent to continue hospitalization to ensure proper monitoring and management of any complications. Ultimately, the decision should strike a balance between the benefits of outpatient management and the risks associated with potential complications, ensuring the patient’s safety and well-being.

Quality of evidence:

Strength of recommendation: Weak.

Discussion

Providing guidelines to new generations of thoracic surgeons is a fascinating challenge for experts in the field. Although PAL has a high incidence and a burdensome clinical and economic impact, greater consensus is still needed regarding its definition and management protocols. The Society of Thoracic Surgeons recently published an expert consensus document on the management of pleural drains after pulmonary lobectomy [30]. A specific area was dedicated in managing the PAL. The recommendations made by the experts, as is often the case in this topic, were based on personal experience and an interpretation of existing evidence. Similarly, we provided recommendations by analysing our results with a high quality of evidence (3/4) but a weak strength of recommendation in each of our 14 key questions.

Starting from the definition of PAL—still not globally standardized—our consensus proposes a dual criterion combining a fixed duration (> 5 days) and the average postoperative stay. This dual approach accommodates ERAS-related shorter hospitalizations and enhances inter-study. Prevention of PAL begins in the operating room at the end of the lung resection, with a check for the presence of IAAL. It represents one of the most important predictors of PAL if we objectively quantify the extent of the air loss through MVT. The immersion test can assist the surgeon in identifying the site to be treated and determining the nature of the problem—whether it involves the staple line, pleural injury, or lung laceration—thus guiding subsequent treatment decisions and management.. The classification into three classes—mild, moderate, and severe—allows for standardization and provides objective data to inform the management of VATS and open anatomical resections. Mild IAALs are generally self-limiting and, therefore, do not require treatment. Moderate IAALs represent the grey area of management, where intraoperative therapies may effectively prevent PAL, but their cost-effectiveness, especially in low-risk patients, remains a matter of debate. Severe IAAL is a reliable predictor of PAL and should always be treated. Once the patients to treat intraoperatively have been defined, possible therapeutic strategies remain recommended. Reinforced staples to prevent PAL in patients with COPD and parenchymal sutures and/or sealants to treat the lesions responsible for IAALs represent possible treatments. However, the current limitations of the evidence suggest that the choice depends on surgeon preference and the clinical context, which is also the case for chest tube size. While recent trends favor the use of progressively smaller chest drains to reduce postoperative discomfort, in cases where a PAL is strongly anticipated, opting for a larger 28 Fr drain instead of a 24 Fr may be advantageous, as it is less likely to become obstructed, especially when chemical pleurodesis, such as talc, is administered. The third step of our recommendations focuses on chest drainage management. Evidence supports the use of digital drainage systems. One of the main advantages of digital chest drain systems compared to traditional analogue underwater systems is that they allow patients to mobilize while on suction. The portable, battery-powered digital units can be easily carried, enabling patients to walk around the ward and use the toilet independently, which may help reduce the risk of other pulmonary complications. Notably, the “wait-and-see” recommendation applies solely to small intraoperative leaks in stable patients; any moderate or severe leak requires immediate management.

Lower suction or water seal levels are preferred to prevent and manage no or mild air leaks. In selected patients, such as those with a significant residual pleural space and in cases of moderate to severe air leaks, suction may be indicated and valuable. The surgeon’s experience and the specific clinical scenario play a fundamental role. Taken together, these recommendations outline a stepwise framework: (1) intraoperative detection and quantification of air leaks; (2) early postoperative monitoring with digital drainage; and (3) targeted intervention for confirmed PAL (> 5 days).

Moreover, PAL etiologies differ—parenchymal suture-line failure, alveolar-pleural fistulas, or pleural-space imbalance—and should guide individualized therapy rather than a uniform approach.

The last step analyzes the possible treatments for confirmed PALs (lasting more than 5 days). A Heimlich valve can safely treat patients with mild PAL and stable general conditions. Chemical pleurodesis should be performed exclusively after verifying adequate lung re-expansion; otherwise, surgical re-exploration is warranted. Surgical exploration should be considered in the presence of empyema or when chemical pleurodesis has failed. Early discharge of patients, even with PAL, can be safe in selected cases. If the patient is stable and meets the criteria for outpatient management, discharge with a chest tube connected to a one-way valve may be a suitable option. When chemical or standard surgical management fails, several adjunctive options may be considered. These include the use of various biological or synthetic sealants, autologous blood patch pleurodesis, and minimally invasive bronchoscopic techniques such as endobronchial valves or one-way intrabronchial devices. Although current evidence is limited and of low quality, these approaches may represent valuable alternatives in selected patients, particularly when re-operation carries excessive risk. Further prospective studies are encouraged to clarify their effectiveness and indications. To facilitate practical application of the recommendations, a schematic summary of the diagnostic and therapeutic sequence for intraoperative and postoperative air-leak management has been developed. This algorithm integrates all fourteen GRADE-based recommendations and provides a quick visual reference for clinical decision-making (Fig. 2).

Fig. 2.

Algorithm for the management of air leaks after pulmonary resection

Limitations

Despite the comprehensive nature of this consensus document, several limitations must be acknowledged. First, the variability in the definitions of prolonged air leaks across different studies presents a challenge in establishing universally applicable recommendations. The reliance on existing literature, which may include studies with heterogeneous populations and varying methodologies, could affect the generalizability of the findings. The systematic review was also limited to English-language studies, potentially excluding relevant research published in languages other than English. The expert panel’s recommendations are also based on the available evidence up to February 2023, and as new studies emerge, the recommendations may require updates to reflect the latest findings. Furthermore, the need for prospective, randomized controlled trials specifically addressing the management of prolonged air leaks limits the strength of the recommendations. Ultimately, implementing these recommendations in clinical practice may vary depending on institutional resources, surgeon experience, and patient-specific factors, which could impact their effectiveness in diverse healthcare settings.

Conclusions

The management of PAL following lung surgery remains a complex challenge that significantly impacts patient recovery and healthcare resources. The collaborative effort of the expert panel underscores the importance of multidisciplinary approaches in addressing the complexities of PAL management. Thoracic surgeons, pulmonologists, and other healthcare professionals must work together to develop and refine management strategies that are both effective and patient-centered. This document serves as a call to action for the medical community to prioritize the standardization of definitions and the development of evidence-based guidelines for the management of PALs. By fostering collaboration and encouraging ongoing research, we can enhance the quality of care for patients undergoing lung surgery, ultimately leading to better health outcomes and more efficient use of healthcare resources. The journey toward improved PAL management must now incorporate technological advances—digital drainage analytics, AI-supported prediction, and ERAS optimization—to personalize treatment and minimize complications. Continued research and multicenter collaboration will be crucial to validate and update these evidence-based recommendations.

Author contribution

F.Z. and L.B. conceived the project and coordinated the expert panel. L.B. served as the methodologist and oversaw the implementation of the GRADE approach. F.Z., M.D.P., F.A., A.A., M.J., A.K., C.S.H.N., D.N., I.S.O., and C.U. contributed to the formulation of the PICO questions, systematic literature review, and drafting of individual recommendations. M.L., R.C., and R.P. critically reviewed the content and contributed to the refinement of the recommendations. L.S. provided senior supervision and final approval of the manuscript. F.Z. and L.B. wrote the main manuscript text. All authors contributed to the discussion, reviewed the manuscript critically for important intellectual content, and approved the final version for publication.

Funding

No funding.

Data availability

No datasets were generated or analysed during the current study.

Declarations

Ethics approval and consent to Participate.

Not applicable.

Competing interest

The authors declare no competing interests.