Temporal arteritis, also known as giant cell arteritis, is an inflammatory vasculopathy affecting medium- and large-sized arteries. While the superficial temporal branch of the carotid artery is particularly susceptible, arteries at any site can be affected. Temporal arteritis is defined by a granulomatous panarteritis with mononuclear cell infiltrates and giant cell formation within the vessel wall.
This unique histologic characteristic confirms the diagnosis of temporal arteritis in biopsy specimens of the temporal artery (TA).
Although temporal artery biopsy has long been considered the gold standard for diagnosis of temporal arteritis, due to its 100% specificity, noninvasive diagnosis using imaging studies is gaining favor.
For example, 2018 European guidelines recommend that the diagnosis of giant cell arteritis can be made without biopsy in cases where there is a high clinical suspicion and a positive imaging test.
This article provides a method for consistent, safe, and cosmetically sensitive biopsy of the superficial temporal artery (Current Procedure Terminology [CPT] code 37609). The relevant anatomy, indications, and contraindications for this procedure are also reviewed. The video below includes an introduction to the procedure.
Introduction by Dr. Andrew Winkler.
The superficial temporal artery is the smaller of 2 terminal branches of the external carotid. It begins behind the mandibular ramus in the substance of the parotid gland and courses superiorly over the posterior aspect of the zygoma. It can be consistently palpated in this region just anterior to the tragus. Approximately 5 cm above the zygoma, it divides into a frontal and parietal branch.
As it crosses the zygomatic process, it is covered by the auricularis anterior muscle, which can aid in identifying the vessel. The superficial temporal artery runs within the superficial temporal fascia, also known as the temporoparietal fascia. This is also the fascia within which the temporal branch of the facial nerve traverses. As the vessel travels superiorly, it is crossed at the level of the lobule by the temporal and zygomatic branches of the facial nerve, which are traveling medially. Safe dissection within the substance of the temporoparietal fascia is permitted because of the divergent course of the vessel from the facial nerve.
While the superficial temporal artery crosses the posterior zygoma and continues posteriorly, the temporal branch of the facial nerve crosses the zygoma in the middle third and courses anteriorly to innervate the frontalis muscle.
Throughout its course, the artery is accompanied by the auriculotemporal nerve, which lies immediately posterior to it, as well as the superficial temporal vein, which lies anterior to the artery. The superficial temporal artery may be safely ligated because of anastomoses with the supraorbital artery of the internal carotid artery, among others. The video below demonstrates relevant anatomy.
Anatomy of the superficial temporal artery.