Clinical Pathways in Neuro-ophthalmology : An ... - E-Lib FK UWKS

Arteritic Anterior Ischemic Optic Neuropathy and Giant Cell Arteritis 103
GCA would not have been diagnosed if only a unilateral TAB had been performed.
Unilaterally positive TABs have been demonstrated in 8 to 14% of retrospective bilateral
TAB series (Hall, 1984). Hall and Hunder retrospectively reviewed 652 TABs at Mayo
Clinic (Hall, 1984). Of these, 234 (36%) revealed GCA, and 193 (82%) were positive on
unilateral TAB. Bilateral TABs were performed in 41 cases (18%) because frozen section
was normal on the first TAB. Of the 193 unilateral TABs, frozen section was abnormal
in 188 and normal in 5. Thus, 86% of the 234 cases would have been diagnosed by
unilateral TAB alone and 14% were diagnosed only because a TAB was performed on
the contralateral side. Hayreh et al reported 76 of 363 patients who underwent a second
TAB because of a strong clinical index of suspicion for GCA (Hayreh, 1997). Seven of
these 76 patients had a positive contralateral TAB. Of the remaining 257 patients with a
negative TAB, none developed signs of GCA on follow-up and these authors thought
that this was indicative that a second TAB would not have been positive.
Boyev et al performed a retrospective study to determine the utility of unilateral
versus bilateral TABs in detecting the pathologic changes of GCA (Boyev, 1999). Of
908 specimens examined from 758 patients, 300 specimens were simultaneous bilateral
biopsies from 150 patients, 72 specimens were bilateral sequential biopsies from
36 patients, and the remaining 536 specimens were unilateral biopsies from 536 patients.
Of the 186 patients who had bilateral simultaneous or nonsimultaneous biopsies,
176 had identical diagnoses on both sides. In four patients, no artery was obtained
on one side. In each of the remaining six patients, five of whom had bilateral
simultaneous biopsies and one of whom had bilateral sequential biopsies performed
8 days apart, the biopsy specimen from one side was interpreted as showing only
arteriosclerotic changes with no evidence of active or healed arteritis, whereas the other
specimen was interpreted as showing either probable healed arteritis (three specimens)
or possible early arteritis (three cases). In none of the six patients with differing
diagnoses between the two sides was one side interpreted as showing definite, active
GCA. Five of six patients were subsequently determined to have GCA, based on a
combination of clinical findings, ESR, and response to treatment with corticosteroids.
The authors concluded that performing simultaneous or sequential TABs improves the
diagnostic yield in at least 3% of cases of GCA, whereas in 97% of cases the two
specimens show the same findings. Thus, in patients in whom only one artery can be
biopsied, there is a high probability of obtaining the correct diagnosis. Nevertheless,
although the improvement in diagnostic yield of bilateral TABs is low, the consequences
of both delayed diagnosis and treatment of GCA as well as the use of systemic
corticosteroids in patients who do not have GCA are of such severity that consideration
should always be given to performing bilateral TABs in patients suspected of having
the disease.
Pless et al reviewed 60 bilateral TAB results and reported a 5% chance of obtaining a
positive biopsy result on one side and a negative biopsy result on the other side (Pless,
2000), whereas Danesh-Meyer et al found a 1% discordance among 91 bilateral
TABs (Danesh-Meyer, 2000). Danesh-Meyer et al performed a meta-analysis of existing
literature and concluded that the overall chance of discordance is about 4% (Danesh-
Meyer, 2000). Danesh-Meyer et al suggest that ‘‘consideration of simultaneous bilateral
TABs appears to be a safe and prudent approach for diagnosis of GCA’’ (Danesh-Meyer,
2000), and Pless et al suggest that ‘‘it is reasonable to biopsy both sides at the same
session in order to increase the likelihood of achievement of a correct diagnosis’’ (Pless,
2000). In editorials following the papers of Danesh-Meyer et al and Pless et al, the
following suggestions were noted: