Surface anatomy site for thoracostomy using the axillary hairline

Abstract

Objective Procedural complication rates associated with tube thoracostomy for pleural decompression is estimated to be between 2 and 25%, with incorrect insertion site being a common problem. We hypothesised that the inferior-most hair follicle in the axillary region would provide an accurate biometric marker to identify the fourth to sixth intercostal space. Methods A prospective cohort of patients requiring computed tomography scan of the chest was recruited from February 2015 to March 2016 at The Alfred Hospital. The inferior-most hair follicle on the patient’s axillary region was tagged with a paperclip, and a radiologist reported this location with reference to the corresponding intercostal spaces. Results Of the 254 enrolled patients, a total of 310 paperclip positions over intercostal spaces were analysed. There were 101 (32.5%) paperclips positioned in the fourth and fifth intercostal spaces with the remainder at the second or third intercostal spaces, and no paperclips placed at the sixth intercostal space or lower. Conclusions This study demonstrated that the inferior-most hair follicle in the axilla corresponded to an area between the second and fifth intercostal spaces. Recognition of this surface anatomy has the potential to eliminate iatrogenic injuries to the diaphragm and sub-diaphragmatic organs, but should not be used as the sole marker due to potential risks from high placement of pleural drains.