Surgical implications of CT-based emphysema scoring in predicting prolonged air leak—defining its role as a risk stratification tool rather than a decision trigger

We read with great interest the article by Naeem et al., “CT-based emphysema score is associated with prolonged air leak after lung resection: a retrospective cohort study”, recently published in the Journal of Thoracic Disease (1). The authors are to be congratulated on analyzing a large contemporary cohort from the United States and on proposing an ipsilateral lung-based emphysema quantification strategy, which represents a meaningful refinement over earlier studies relying on bilateral lung assessment. Their findings further support the association between emphysematous lung parenchyma and prolonged air leak (PAL) following lung cancer resection (2).

From the perspective of thoracic surgical practice, we would like to offer several additional considerations that may help further contextualize the clinical interpretation of the emphysema score and its potential role in perioperative decision-making.

First, the clinical implication of the proposed 16% emphysema cut-point merits careful interpretation. Although this threshold demonstrated a statistically significant association with PAL, its reported sensitivity was relatively low (38%), and the addition of the emphysema score resulted in only a modest and statistically non-significant improvement in model discrimination [area under the curve (AUC): 0.699 vs. 0.673 for the base model, P=0.22]. In routine surgical practice, predictive tools are often expected to reliably identify patients at increased risk who may benefit from targeted preventive strategies (3). In this context, the current performance characteristics suggest that the emphysema score may be more suitable for identifying patients at low risk of PAL, rather than serving as a definitive trigger for intraoperative intervention. Clarifying this distinction may facilitate more appropriate clinical application of the proposed threshold.

Second, PAL is a multifactorial postoperative outcome influenced by both patient-related factors and surgical management (4). While computed tomography (CT)-based emphysema scoring provides an objective measure of parenchymal vulnerability, intraoperative technique and postoperative management—such as fissure handling, stapling strategy, use of reinforcement materials, and chest tube management protocols—can substantially modify the clinical expression of this risk. As these variables were not incorporated into the current analysis, the emphysema score may be best interpreted as a background risk indicator whose impact is modulated by surgical strategy, rather than as an isolated determinant of PAL.

Third, the subgroup findings in patients with borderline pulmonary function are of particular interest. The observed association between emphysema score and PAL among patients with both forced expiratory volume in 1 second (FEV₁) and diffusion capacity of the lungs for carbon monoxide (DLCO) <60% may offer useful insights for risk stratification in this challenging population. However, given the limited sample size of this subgroup (n=32), these results should be viewed as exploratory. Additional validation in larger, independent cohorts would be valuable before such findings are applied more broadly to surgical decision-making in patients with marginal pulmonary reserve.

In conclusion, the study by Naeem et al. provides important evidence supporting CT-based emphysema quantification as a predictor of PAL after lung resection. From a thoracic surgical standpoint, the emphysema score appears to function most effectively as an adjunctive tool for risk stratification, particularly in identifying patients unlikely to develop PAL, rather than as a standalone determinant guiding operative strategy. Further prospective and multicenter studies incorporating operative and postoperative variables may help clarify how emphysema scoring can be optimally integrated into comprehensive surgical decision-making frameworks.

Acknowledgments

None.

Footnote

Provenance and Peer Review: This article was a standard submission to the journal. The article did not undergo external peer review.

Funding: None.

Conflicts of Interest: Both authors have completed the ICMJE uniform disclosure form (available at https://jtd.amegroups.com/article/view/10.21037/jtd-2025-1-2621/coif). The authors have no conflicts of interest to declare.

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References

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