Pulmonology Pulmonology
Rev Port Pneumol 2014;20:174-6 - Vol. 20 Num.3 DOI: 10.1016/j.rppneu.2014.01.009
Letter to the Editor
CT-guided transthoracic lung biopsy: Predictive factors of pneumothorax
Biópsia pulmonar transtorácica guiada por TC: factores preditivos de pneumotórax
J.F. Cruz, , R. Rolo, L. Iglésias, J. Cunha
Serviço de Pneumologia, Hospital de Braga, Braga, Portugal
Dear Editor,

Computed tomography (CT) guided transthoracic lung biopsy (TTLB) is a well established method in the diagnosis of intra-thoracic lesions with good diagnostic yield.1 Pneumothorax is the most frequent complication with an incidence varying between 8% and 64%.2

The objective of this study was to evaluate potential risk factors associated with the occurrence of pneumothorax in CT-guided TTLB. We performed a retrospective study of patients undergoing CT-guided TTLB between 2007 and 2012 in Braga Hospital. Clinical data and radiologic images of patients were reviewed.

A total of 269 TTLB were performed (201 fine needle aspiration biopsies and 68 core biopsies), in 209 patients with a mean age of 64.2 years, 75.8% male, 60% with smoking habits. Pneumothorax rate was 20.8%. Treatment of pneumothorax with chest drainage was necessary in 10/269 biopsies (3.7%). An initial univariate analysis identified the following risk factors: larger needle size (p=0.033), smaller size of the lesion (p=0.001) and absence of pleural contact (p<0.001) – Table 1. A multiple logistic regression analysis has identified absence of pleural contact (p<0.001; R2 adjusted 0.107) and size of the lesion (p=0.030; R2 adjusted 0.120) as significant independent risk factors for the occurrence of pneumothorax. Pneumothorax occurred in 41/111 (36.9%) biopsies in lesions without pleural contact vs 15/158 (9.5%) with pleural contact. Pneumothorax rate for lesions ≤2cm was 31% compared with 15.4% for lesions >4cm. Age, gender, smoking habits, presence of emphysema, needle size, presence of cavitation, contours, location and depth of lesion were not significantly associated with increased risk of pneumothorax.

Table 1.

Univariate analysis of demographic characteristics of patients and multiple variables of TTLB.

Variables  All biopsies  Pneumothoraxp value 
    No  Yes   
Biopsies, no.  269  213 (79.2)  56 (20.8)  – 
Age, years  64.2±13.6  64.6±13  62.8±15.8  0.752a 
Gender male/female  204/65  167/46  37/19  0.055b 
Smoking habits
Smoker  80 (29.8)  62 (29.1)  18 (32.1)  0.748b
Ex-smoker  81 (30.1)  63 (29.6)  18 (32.1) 
Non smoker  108 (40.1)  88 (41.3)  20 (35.8) 
Needle size
FNAB (25Ga)  201 (74.7)  153 (71.8)  48 (85.7)  0.033b
CB (18Ga)  68 (25.3)  60 (28.2)  8 (14.3) 
Lesion size, mm  48.5±28  51.3±28.9  37.4±21  0.001a 
Lesion depth, mm  60.4±21.8  59.4±22.3  64.2±19.5  0.075a 
Presence of emphysema  78 (29)  58 (27.2)  20 (35.7)  0.213b 
Lesion location
Right upper lobe  81 (30.1)  61 (28.6)  20 (35.7)  0.762b
Middle lobe  13 (4.8)  9 (4.2)  4 (7.1) 
Right lower lobe  58 (21.6)  46 (21.6)  12 (21.5) 
Left upper lobe  68 (25.3)  55 (25.8)  13 (23.2) 
Left lower lobe  42 (15.6)  35 (16.5)  7 (12.5) 
Mediastinum  7 (2.6)  7 (3.3)  0 (0) 
Lesion contours
Regular  31 (12.3)  24 (11.2)  9 (16.1)  0.511b
Irregular/spiculated  216 (80.3)  175 (82.2)  41 (73.2) 
Lobulated  20 (7.4)  14 (6.6)  6 (10.7) 
Presence of cavitation  24 (8.9)  17 (30.4)  7 (12.5)  0.291b 
Pleural contact
Yes  158 (58.7)  143 (67.1)  15 (26.8)  <0.001b
No  111 (41.3)  70 (32.9)  41 (73.2) 

Data presented as mean±SD or no. (%).


Mann–Whitney U test.


Pearson χ2 test.

In our study, the absence of pleural contact was the most significant risk factor associated with the occurrence of post-TTLB pneumothorax. These data were corroborated by another retrospective study of Khan et al.3 in which lesions in the lung parenchyma had a higher pneumothorax rate than lesions located in the pleura or thoracic wall. Another significant risk factor identified was lesion size. There seems to be a gradual increase in the risk of pneumothorax to progressively smaller lesions. In a retrospective analysis of 660 biopsies, Yeow et al.4 showed that the risk of pneumothorax was about 11 times higher in lesions ≤2cm than in lesions >4cm.

In conclusion, this study supports the performance of CT-guided TTLB in the study of undetermined lung lesions as a safe method. Although the overall incidence of pneumothorax was 20.8%, the clinically significant pneumothorax rate requiring treatment with chest tube drainage was low (3.7%).


João Filipe Cruz conceived this study, collected the data and carried out the statistical analysis. Rui Rolo collected the data, collaborated in the inception of the study and supervised all aspects of its implementation. Lourdes Iglésias and João Cunha contributed to the critical revision of the manuscript. All the authors contributed to the interpretation of the results and the proof reading of the manuscript.

Conflicts of interest

The authors have no conflicts of interest to declare.

R.B. Katherine
Transthoracic needle biopsy
Semin Intervent Radiol, 28 (2011), pp. 87-97 http://dx.doi.org/10.1055/s-0031-1273943
M.J. Charig,A.J. Philips
CT-guided cutting needle biopsy of lung lesions—safety and efficacy of an out-patient service
Clin Radiol, 55 (2000), pp. 964-969 http://dx.doi.org/10.1053/crad.2000.0964
M.F. Khan,R. Straub,S.R. Moghaddam,A. Maataoui,J. Gurung,T.O.F. Wagner
Variables affecting the risk of pneumothorax and intrapulmonal hemorrhage in CT-guided transthoracic biopsy
Eur Radiol, 18 (2008), pp. 1356-1363 http://dx.doi.org/10.1007/s00330-008-0893-1
K.M. Yeow,I.-H. Su,P. Kuang-Tse,T. Pei-Kwei,L. Kar-Wai,C. Yun-Chung
Risk factors of pneumothorax and bleeding: multivariate analysis of 660 CT-guided coaxial cutting needle lung biopsies
Corresponding author. (J.F. Cruz joaoffcruz@gmail.com)
Copyright © 2013. Sociedade Portuguesa de Pneumologia
Rev Port Pneumol 2014;20:174-6 - Vol. 20 Num.3 DOI: 10.1016/j.rppneu.2014.01.009
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