Fig. 3.

Anatomy of the intercostal space and the intercostal artery. The cross-sectional view of the posterolateral intercostal space ( a ) reveals the neurovascular bundle is along the costal groove. The percutaneous chest tube trajectory through the intercostal space is ideally along the superior border of the rib which minimizes injury to the intercostal nerve and vessels. The intercostal artery courses along the inferior border of the rib except in the paravertebral region ( b ). Needle access superior to the rib in the paravertebral region may not avoid injury to the intercostal artery since the posterior intercostal artery courses in the mid and lower intercostal space near the spine.