Risk of Primary Spontaneous Pneumothorax According to Chest Configuration.

BACKGROUND: We compared the chest configurations of patients with primary spontaneous pneumothorax (PSP) and age-sex-matched controls to determine the presence of chest wall deformities in patients with PSP.

METHODS: We retrospectively enrolled 166 male patients with PSP (age, 18-19 years) and 85 age-sex-matched controls without PSP, who simultaneously underwent chest computed tomography (CT) and radiography at one of two institutes. After correcting for height, the following thoracic parameters were comparatively evaluated between the two groups: maximal internal transverse ( T ) and anteroposterior ( W ) diameters of the chest, maximal internal lung height ( H ), Haller index ( T / W ), and T /Height, T / H , W /Height, W / H , and H /Height ratios.

RESULTS: Patients were taller than the control subjects (176.5 cm ± 5.9 cm versus 174.4 cm ± 5.6 cm; p  = 0.007). After controlling for height, the patient group exhibited lower T and W and greater H and Haller index values than the control group ( T : 95% confidence interval [CI], 24.8-25.2 cm versus 25.9-26.5; W : 95% CI, 8.9-9.2 cm versus 10.1-10.6 cm; H: 95% CI, 25.2-25.9 cm versus 23.4-24.4 cm; and Haller index, 95% CI, 2.7-2.9 versus 2.4-2.6; all, p  < 0.001). The patient group also exhibited lower T /Height, T /H, W /Height, and W /H ratios and greater H /Height ratio than the control group.

CONCLUSIONS: Patients with PSP have an anteroposteriorly flatter, laterally narrower, and craniocaudally taller thorax than subjects without PSP, suggesting that chest configuration is associated with the development of pneumothorax.