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Updated: Aug 7, 2026
Robotic-assisted Bronchoscopy Combined with Multimodal Imaging for Targeted Lung Cryobiopsies
Published on: July 19, 2024
Trajectory-Based Trauma Index and Pleural Infiltration Predict Pneumothorax After CT-Guided Lung Cryoablation
Michael P Brönnimann1, Christoph A Binkert2, Johannes T Heverhagen3
1Division of Interventional Radiology, Department of Radiology, Stanford University School of Medicine, Stanford, California; Department of Diagnostic, Interventional and Pediatric Radiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
Purpose:
To evaluate associations of a newly developed trajectory-based trauma index (TTI) and tumor-related pleural infiltration with pneumothorax after computed tomography (CT)-guided lung cryoablation.
Materials And Methods:
This retrospective single-center observational cohort included procedures from May 2017 through January 2026. Eligible procedures involved transpulmonary cryoablation of primary or metastatic lung malignancy in adults. Exclusions were extrapleural access, ipsilateral pleural effusion or drainage, concomitant ipsilateral microwave ablation, and incomplete data. Ablation was indicated after multidisciplinary assessment; contraindications included uncorrectable coagulopathy, active infection, anesthesia intolerance, or no safe access. The primary end point was pneumothorax on immediate CT or 2-hour radiography; chest tube placement before discharge was secondary. TTI, the primary exposure, summed contributions from cryoprobes and biopsy needles based on diameter, aerated-lung traversal, and pleural entry angle. Pleural infiltration was a prespecified coexposure and relative entry height a covariate. Associations were evaluated with logistic regression.
Results:
Ninety procedures in 69 patients were analyzed. Across 230 pleural punctures, median diameter was 2.1 mm (IQR, 2.1-2.1); aerated-lung traversal, 25.0 mm (IQR, 8.9-38.7); and entry angle, 52.8° (IQR, 38.8°-69.9°). Pneumothorax occurred in 56 of 90 procedures (62%; 95% CI, 51%-72%); 34 of 90 (38%) required chest tubes. Higher TTI was associated with pneumothorax (odds ratio [OR], 21.87; 95% CI, 4.47-106.99; P < .001), whereas greater pleural infiltration was associated with lower odds (OR, 0.56; 95% CI, 0.40-0.78; P < .001). TTI was associated with chest tube placement (OR, 5.02; 95% CI, 1.60-15.78; P = .006).
Conclusions:
In this retrospective single-center cohort, higher TTI and less extensive pleural infiltration were associated with pneumothorax.
