Thyroid Ima Artery

arteria thyroidea ima

The thyroid ima artery is an unpaired, inconstant artery present in approximately 3-10% of individuals, arising from the brachiocephalic trunk, the arch of the aorta, or the right common carotid artery. It ascends in front of the trachea to supply the thyroid isthmus from below, entering the inferior pole of the isthmus or the lower thyroid lobes.

Region: Neck

Clinical Relevance

Clinical Notes

The thyroid ima artery is a potentially catastrophic hazard during emergency cricothyrotomy and surgical tracheostomy, where its anterior tracheal course places it directly in the midline incision. An inadvertent cut through this artery in an emergency airway setting can produce massive haemorrhage that obscures the operative field. Preoperative imaging identifying the artery is impossible in emergencies; surgeons must be aware of this variant. In elective thyroidectomy, superior thyroid artery ligation typically controls the thyroid ima territory by collateral flow.

Pathology

Common Injuries & Conditions

Thyroid Ima Artery Haemorrhage in Tracheostomy

An unrecognised thyroid ima artery crossing the anterior trachea in the midline tracheostomy or cricothyrotomy incision produces unexpected haemorrhage that may be life-threatening in an emergency airway setting; immediate pressure packing and vascular control by ligation proximal to the thyroid are required.