Anatomical study of phrenic nerve course in relation to neck dissection

Abstract

The present study sought to clarify the course of the phrenic nerve and its correlation with anatomical landmarks in the neck region. We examined 17 cadavers (30 sides). In each, the phrenic nerves was dissected from the lateral side of the neck, and its position within the triangle formed by the mastoid process and sternal and acromial ends of the clavicle was determined. The point where the phrenic nerve arises in the posterior triangle was found to be similar to the point where the cutaneous blanches of the cervical plexus emerge at the middle of the posterior border of the sternocleidomastoid muscle. In the supraclavian triangle, the phrenic nerve crosses the anterior border of the anterior scalene muscle near Erb's point where the superficial point is 2-3 cm superior from the clavicle and posterior border of the sternocleidomastoid muscle. The phrenic nerve arises in the posterior triangle near the nerve point, then descends to the anterior surface of the anterior scalene muscle in the supraclavian triangle. It is necessary to be aware of the supraclavian triangle below Erb's point during neck dissection procedures.

A quantitative analysis of the dimensions and content of the vertebral triangle

“…On occasion (incidence not reported) the phrenic nerve was found within the triangles reported by Singal et al [27]. The course of the phrenic nerve in the neck has been described as originating from the cervical plexus in the posterior triangle of the neck, descends and runs obliquely across the anterior scalene muscle and finally, runs anterior to the subclavian artery before entering the thorax [14,20]. However, other studies suggest that the phrenic nerve descends vertically across the anterior scalene muscle [4,10,13,29].…”

An unusual anatomical variant of the left phrenic nerve encircling the transverse cervical artery

“…The aberrant origin of the TCT can lead to potential impairment of the PN. Hamada et al [5] also reported that lateral displacement of the PN could increase the risk of PN injury during internal jugular or subclavian venous catheter placement and brachial plexus block. In addition, marked lateral deviation and subsequent strain of the PN in the neck could increase the risk of nerve injury or nerve dysfunction [16].…”

A Rare Case of C2 Sensory Blockade with Preserved Phrenic Nerve Function in an Obstetric Patient

“…The phrenic nerve arises from C3–5 before providing motor innervation to the diaphragm [ 12 ], and despite demonstrating a C2 sensory blockade our patient retained at least partial diaphragmatic function exhibited by the ability to initiate breaths. Differential nerve block in which sensory blockade is several levels higher than motor blockade may occur with both spinal and epidural anesthesia [ 13 , 14 ].…”