Mapping the course of long thoracic nerve

Abstract

Long thoracic nerve (LTN) injury has been reported after radiotherapy, trauma, patient's position, transaxillary breast augmentation, implantation of transvenous leads, anaesthetic nerve block and transaxillary incision. Denervation of the serratus anterior muscle at LTN injury results in loss of scapular stabilization or winged scapula. LTN injury results in prolonged disability and impact on quality of life for patient and potential medicolegal concerns for the physician. The purposes of this study is to map the course of LTN relative to the scapula and sternum, thereby developing guidelines to aid in the prevention of LTN injuries. The course of the long thoracic nerve were investigated in 15 adult Turkish cadavers. Each cadaver was placed in the transaxillary thoracotomy positions. The LTN was exposed bilaterally in its course from axilla to its penetration into serratus anterior muscle. The nerve courses vertically, gets progressively closer to the anterior border of the scapula. The length of the LTN was measured as 201.4±20.7 mm on the right and 208.6±17 mm on the left. The distance from main trunk to clavicle was 28.8±6.3 mm on the right and 29.8±3.6 mm on the left side. The distance from sternal angle to LTN was measured as 212.4±21 mm on the right and 220.5±27.5 mm on the left. The distance between xiphoid process was 246.5±21.8 mm on the right and 242.8±27.9 mm on the left. The distance from scapul ar rim to LTN was 61.9±10.7 mm on the right and 57.6±13 mm on the left. The length of thickest branch of LTN was 22.6±10.4 mm on the right and 31.4±28.1 mm on the left. The diameter of the thickest branch was 1.6±0.59 mm on the right and 1.63±0.85 mm on the left. The number of side branches was 6.44±2.06 ones on the right and 6.45±2.77 ones on the left side. Bifurcation number of terminal branch of LTN was 2.55±0.72 ones on the right and 2.54±0.68 ones on the left. By using these anatomical guidelines, we believe that the incidence of iatrogenic long thoracic nerve injury can be minimized. © neuroanatomy.org