Diagnosing temporal arteritis: duplex vs. biopsy
From Kaiser Permanente Northwest, Vancouver, USA
Address correspondence to Dr M.S. Alberts, Vancouver Medical Office, 2211 East Mill Plain Blvd, Vancouver, Washington 98661, USA. email: michael.s.alberts{at}kp.org
Received 4 May 2007 and in revised form 6 August 2007
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Abstract |
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Background: Temporal artery biopsy is the traditionally-accepted method of diagnosing temporal arteritis, but is of limited sensitivity.
Aim: To compare the clinical decisions made after negative temporal artery biopsy vs. negative temporal artery duplex, and the effects on patient outcomes.
Design: Retrospective analysis.
Methods: Of 290 patients suspected of having temporal arteritis, 147 underwent bilateral temporal artery duplex with a negative result, and 143 underwent unilateral temporal artery biopsy with a negative result. These groups were compared. Dependent measures included the proportion of patients in each group whose steroids were discontinued by their primary care doctor after either negative test, and the difference in the number of alternative diagnoses considered after a negative test. The incidence of blindness in each group was also compared, as a measure of adverse outcomes. Patients were then stratified by pre-test probability of having the disease, and compared using the same measures.
Results: Equivalent proportions of patients in the two groups had steroids discontinued after a negative test result, even when further stratified into risk groups by the probability of having temporal arteritis. No differences in adverse outcomes or number of alternative diagnoses considered were noted between groups.
Discussion: In clinical practice, bilateral temporal artery duplex served the same function as biopsy, but without subjecting patients to the potential morbidity of a surgical procedure. Temporal artery biopsy could be reserved only for situations where the duplex result is inconsistent with the clinical picture, and the biopsy result, if different from the duplex result, might influence the treatment decision.