Too few, too late. Temporal artery biopsy in cranial arteritis.

A retrospective study of 66 patients with cranial arteritis diagnosed clinically was undertaken, investigating the incidence, timing and adequacy of temporal artery biopsy. Only 36 patients underwent biopsy, of which 24 were positive, 8 negative and 4 surgically inadequate. Only 13 of 24 biopsy positive patients had clinical arterial abnormalities; 5 of 8 biopsy negative patients had clinical abnormalities. Three biopsy positive patients had an ESR of less than 40 mm/hr. The average delay from onset of symptoms to biopsy was 128 days; excluding 3 patients with a delay greater than 6 months, the average delay was 52 days. The average time to diagnosis in the "no biopsy" group from the onset of symptoms was 60 days (excluding 1 patient with a delay greater than 6 months). Serious complications occurred in 15 patients. Of 36 patients undergoing biopsy, 4 had complications (prior to biopsy), whilst of the 30 "no biopsy" patients 11 suffered a serious complication (significant chi 2 = 4,716 with Yates correction, p less than 0.05). The study suggests that diagnosis is delayed in all groups. Earlier biopsies in more patients with meticulous technique would probably speed the diagnosis of cranial arteritis and reduce the incidence of preventable complications.