Patient specific characteristics and risk of iatrogenic pneumothorax after CT-guided biopsy of the lung parenchyma.

Background: CT-guided transthoracic needle aspiration biopsy (CT-TTNAB) is a cornerstone in diagnosing peripheral lung lesions, but iatrogenic pneumothorax (iPTX) is a common, adverse event. The presence of emphysema is a well-known risk factor but emphysema may vary from light to severe, and discrepancy is important for precise prognostic application. Aim: To validate that decreasing the diffusion capacity of carbon monoxide (DLCO) is a significant risk factor for the development of iPTX and need for insertion of a pleural device. Methods: We conducted a retrospective study of patients undergoing CT-TTNAB for suspected lung cancer between 1 January to 31 December 2023. We recorded age, sex, packyears, performance score (PS), FEV1 (%, categorized), FVC (% of predicted) and DLCO categorized into four groups: >80%, 60-79%, 40-59% and <40% of predicted. Association with iPTX and need for insertion of a pleural device were investigated with multiple logistic regression. Results: Of 328 patients undergoing CT-TTNAB, 160 patients developed iPTX. Multiple logistic regression demonstrated that DLCO < 60% was an independent risk factor for both iPTX (DLCO 40-59%: odds ratio (OR) 2.8; <40%: OR 4.8), and chest tube insertion (OR 5.1, respectively, 15.3). Concerning other variables, only FEV1 30-49% was an independent risk factor (OR 6.5 for chest tube insertion). Conclusion: This study adds novel information to the risk assessment before a CT-TTNAB procedure. We suggest that decreasing DLCO expressed <60%predicted is a clinically meaningful risk factor for both the development of iPTX and need for insertion of a pleural device.