The Unusual Origin of the Sternocleidomastoid Artery from the Lingual Artery

The sternocleidomastoid (SCM) artery supplying blood to the SCM muscle has different origins according to its anatomical segment. The authors performed cadaveric neck dissection to review the surgical anatomy of neurovascular structures surrounding the carotid artery in the neck. During the dissection, an unusual finding was cited in which the SCM artery supplying the middle part of the SCM muscle originated from the lingual artery (LA); it was also noted that it crossed over the hypoglossal nerve (HN). There have been extremely rare reports citing the SCM artery originated from the LA. Though the elevation of the HN over the internal carotid artery was relatively high, the vascular loop crossing over the HN was very close to the carotid bifurcation. Special anatomical consideration is required to avoid the injury of the HN during carotid artery surgery.