Excisional biopsy for Giant Cell Arteritis
How should a surgeon be instructed to obtain an excisional biopsy for Giant Cell Arteritis, and how much artery should be taken?
In the absence of a palpable abnormality of the temporal artery, biopsy of the main trunk on the most symptomatic side is performed first. Biopsy length guidelines based on GCA’s propensity for skip lesions have traditionally suggested a need for segments up to 3 to 6 cm, although some studies have suggested that lengths of 2 cm will achieve adequate sensitivity. Unilateral biopsy has a pooled sensitivity of 87%. Additional/contralateral biopsies increase the sensitivity by 5%. The negative predictive value of bilateral negative temporal artery biopsies in a patient with cranial symptoms is 91%. Occipital artery biopsy may also be done in patients with posterior-predominant headaches and other signs/symptoms highly consistent with GCA.
