Purpose: To determine the rate, clinical significance, and predictors of delayed pneumothorax after CT-guided lung biopsy.
Methods: Medical and imaging records of all patients who underwent CT-guided lung biopsy between January 1, 2012, and January 9, 2015, were reviewed. "Early pneumothorax" was defined as one visualized on CT scan at the time of biopsy, "delayed pneumothorax" as one discovered on the first follow-up chest X-ray (CXR), and "clinically significant pneumothorax" as one requiring chest tube placement.
Results: Three hundred fifty-seven lung biopsies were performed; 79 patients did not have follow-up CXR and were excluded. Out of 278 cases included in the study, early pneumothorax occurred in 109 patients. Follow-up CXRs were available in the remaining 169 patients without early pneumothorax and were obtained 3.1 ± 2.9 h after biopsy. The rate of delayed pneumothorax was 8.6% (24/278). Clinically significant pneumothorax occurred in 10/24 (41.7%) patients with delayed pneumothorax, including one case of tension pneumothorax. Patients with delayed pneumothorax (n = 24) had smaller lesion long axial diameter (18.58 ± 9.84 vs 25.83 ± 17.69 mm, p = 0.005), longer intrapulmonary needle tract (23.45 ± 14.98 vs 14.17 ± 14.49, p = 0.004), and lower FEV1/FVC ratio (53.30 ± 22.47 vs 71.15 ± 13.77, p = 0.015), compared to those without delayed pneumothorax (n = 145). The length of intrapulmonary needle tract was the only independent predictor of delayed pneumothorax (p = 0.008) and symptomatic delayed pneumothorax (p = 0.019).
Conclusion: Obtaining a routine follow-up CXR in all patients after CT-guided lung biopsy appears warranted, given the high rate of delayed pneumothorax and large percentage of patients who will require a chest tube. The only independent predictor of (symptomatic) delayed pneumothorax was the length of intrapulmonary needle tract.
Keywords: Chest X-ray; Delayed; Lung biopsy; Pneumothorax.