Effect of needle tract bleeding on occurrence of pneumothorax after transthoracic needle biopsy

Abstract

Purpose: Occasionally bleeding along the needle trajectory is observed at post-biopsy computed tomographic sections. This study was designed to evaluate the possible effect of needle tract bleeding on the occurrence of pneumothorax and on requirement of chest tube insertion. Materials and methods: Two hundred eighty-four needle biopsies performed in 275 patients in whom the needle traversed the aerated lung parenchyma were retrospectively reviewed. Bleeding along the needle tract, occurrence of pneumothorax and need for chest tube insertion, type and size of the needle, size of the lesion, length of the lung traversed by the needle, presence or absence of emphysema were noted. Effect of these factors on the rate of pneumothorax and needle-tract bleeding was evaluated. The data were analyzed by x(2) test. Results: Pneumothorax developed in 100 (35%) out of 284 procedures requiring chest tube placement in 16 (16%). Variables that were significantly associated with an increased risk of pneumothorax were depth of the lesion (P < 0.001) and severity of emphysema (P < 0.05). There was bleeding along the needle tract in 18.6% (n = 53) of the procedures. Pneumothorax occurred in 18 (33.9%) out of 53 procedures in which tract-bleeding was observed and in 82 (35.4%) out of 231 procedures in which tract-bleeding was not seen. The difference between the two groups was not significant (P > 0.05). However, analysis of the relation between length of lung traversed by the needle, tract-bleeding and pneumothorax rate indicated that tract-bleeding had a preventive effect on development of pneumothorax (P < 0.001). Occurrence of tract bleeding also had preventive effect on pneumothorax in the presence of emphysema (P < 0.05). The only variable which had effect on occurrence of tract-bleeding was the length of the lung traversed by needle (P < 0.001). Requirement for chest tube insertion was smaller in the tract-bleeding group than non-tract bleeding group, 11% (2/18) to 17% (14/82), respectively. But this difference was not significant statistically (P > 0.05). Conclusion: Bleeding in the needle tract has a preventive effect on the occurrence of the pneumothorax in deep-seated lesions and in the presence of emphysema, although it does not affect the overall rate of pneumothorax.