Effect of Needle-Tract Bleeding on Pneumothorax and Chest Tube Placement Following CT Guided Core Needle Lung Biopsy

Introduction Computed tomography (CT)-guided core needle lung biopsy (CT-CNB) is a reliable and safe diagnostic procedure; the most common complication of CT-CNB is pneumotho-rax [1, 2]. Some invasive techniques, such as injection of sealant materials (e.g., autologous blood patch, collagen plugs, fibrin glue, normal saline, hydrogel plugs) into the biopsy tract have been studied for their ability to decrease the risk of pneumothorax [3-5]. The use of an autologous blood patch is perhaps the most widely known technique, but it has shown varying results [6]. Previously, we evaluated the effect of needle-tract bleeding (NTB) on pneumothorax using post-biopsy CT images from a limited population for the first time [7]. This study aimed at determining the predictive variables for the development of NTB in a large patient population. We also evaluated whether NTB can function as a blood patch and prevent pneumothorax development and the resultant chest tube placement. Materials and Methods Patients The protocol of this retrospective study was approved by the institutional review board. Written informed consent was not required because of the retrospective nature of the study. From January 2001 to October 2006, 872 consecutive patients underwent CT-CNB. We excluded patients who had refractory coagulopathy (INR ≥ 1.5) or thrombocyte counts less than 75,000, lesions with a suspected vascular origin, severe respiratory disease (e.g., pulmonary arterial hypertension, or interstitial pulmonary disease), and those who refused to undergo the procedure. The four hundred biopsies in which the needle did not cross the aerated lung parenchyma were also excluded. Twenty-one cases of mediastinal lesions were excluded as well because they did not require a needle path to traverse through Background: Bleeding in the biopsy tract has been studied for its ability to decrease the risk of pneumo-thorax with indefinite results in the previous studies. Purpose: To investigate the risk factors for needle-tract bleeding (NTB) and the possible effect of NTB on the pneumothorax and resultant chest tube placement after CT-guided cutting needle biopsy (CT-CNB) of pulmonary lesions. Methods: Predictive variables for NTB and the effect of NTB on the development of pneumothorax and consequent chest tube placement were retrospectively determined in 416 patients who had undergone an 18-gauge non-coaxial CT-CNB (338 men and 78 women; average age, 59.3 years). Patient-related parameters were age, gender, patient position, and severity of pulmonary emphysema. Lesion-related variables were size, localization, and contour characteristics of the lesion. Procedure-related variables were the presence of atelectasis, pleural tag, and fissure in the needle-tract, length of the aerated lung parenchyma crossed by needle, needle entry angle, number of pleural punctures, the experience of the operator, and procedure duration. All variables were analyzed by x 2 test and logistic regression analysis. Results: NTB was demonstrated in 142 of 421 (33.7%) procedures. The predictive variables of NTB were smaller lesion size (p = 0.011) and greater lesion depth (p = 0.002). In patients without emphysema around the lesion, the pneumothorax developed in 44/190 cases (23.1%) without NTB and in 12/95 procedures (12.6%) with NTB (p <0.001). Conclusion: NTB may have a preventive effect on pneumothorax development, particularly in the absence of emphysema around the lesion.