Importance of specimen length during temporal artery biopsy

Sir,

We welcome the interest of Rohman et al in our study that confirmed arterial specimen length as an independent factor predicting histopathological diagnosis of giant cell arteritis (GCA) during temporal artery biopsy (TAB). In our cohort, the second largest published to date, biopsies with post-fixation length at least 0.7 cm had a positivity rate of 24.8 per cent, double than those with specimen smaller than 0.7 cm (12.9 per cent). Other than specimen length differences, there was no significant variation in surgical technique of TAB across the different hospitals. Technique was not evaluated as a potential prognostic factor of outcome.

The usefulness of TAB in the diagnosis of GCA has been debated before (1), but an abnormal biopsy itself is one of the five criteria of the American College of Rheumatology score (2). Patients with high index of suspicion for GCA are, indeed, treated promptly before the result of TAB becomes available. Steroids have significant side-effects (3) and their prolonged use in the absence of pathology is hardly justified. Finally this study has shown that TAB outcomes could be dependent on local referral practices; over-utilisation of the method beyond the recommended guidelines (4) could also be responsible for lower positivity rates (5).

We believe that every change in clinical practice aiming to make the diagnosis of GCA more robust would be welcome and, therefore, optimisation of the TAB method would be a step to the right direction.

Yours sincerely

E. Ypsilantis
Department of General Surgery
Maidstone and Tunbridge Wells NHS Trust Hospitals
makypsi@yahoo.com

References

1. Lenton J, Donnelly R, Nash JR. Does temporal artery biopsy influence the management of temporal arteritis? QJM. 2006; 99(1): 33-6.

2. Hunder GG, Bloch DA, Michel BA et al. The American College of Rheumatology1990 criteria for the classification of giant cell arteritis. Arthritis Rheum 1990; 33:1122-8.

3. Kyle V, Hazleman BL: Treatment of polymyalgia rheumatica and giant cell arteritis. Relation between steroid dose and steroid associated side effects. Ann Rheum Dis 1989; 48: 662-6.

4. Dasgupta B, Borg FA, Hassan N, et al. BSR and BHPR Standards, Guidelines and Audit Working Group. BSR and BHPR guidelines for the management of giant cell arteritis. Rheumatology (Oxford) 2010; 49: 1594–1597.

5. Goslin BJ, Chung MH. Temporal artery biopsy as a means of diagnosing giant cell arteritis: is there over-utilization? Am Surg. 2011 Sep; 77(9):1158-60.

• Commentor: E. Ypsilantis - Maidstone and Tunbridge Wells NHS Trust Hospitals
• Date: Dec 13, 2011

Sir,

We read with great interest the article by Ypsilantis et al, raising the question of optimum temporal artery biopsy (TAB) length. This is a large cohort yet the positive rate remains only 21%. Alison et al and others have also demonstrated an average biopsy length of 0.7cm, with higher positive rates (1). However, Achkar et al reviewed 535 patients with an average biopsy length of 3.6cm and obtained 33% positive rate (2), thus there continues to remain great heterogeneity in findings; possibly due to skip-lesions, length of biopsy, prior steroid treatment and atypical presentation.

Our own experience is of a low positive rate, with similar TAB lengths and with more junior surgeons taking longer biopsies. As surgical technique influences specimen length, have the authors investigated this variable?

Finally, should we be doing TAB at all? It has been suggested that TAB makes little difference to treatment and is not without risks (3). Is it not purely academic, given that a score of ≥3 on the American College of Rheumatology criteria is very accurate (sensitivity 93.5% and specificity 91.2%) (4,5), and irrespective of TAB result these patients will receive the same treatment?

L Rohman, A Phillips
Accident & Emergency Department
The James Cook University Hospital, Middlesbrough
leburrohman@doctors.org.uk

References

1. Allison MC, Gallagher PJ. Temporal artery biopsy and corticosteroid treatment. Ann Rheum Dis1984;43:416–17.

2. Achkar AA, Lie JT, Hunder GG, et al. How does previous corticosteroid treatment affect the biopsy findings in giant cell (temporal) arteritis? Arch Intern Med 1994;120:987–92.

3. Lenton J, Donnelly R, Nash JR. Does temporal artery biopsy influence the management of temporal arteritis? QJM (2006) 99(1):33-36

4. Haist S A. Stroke after temporal artery biopsy. Mayo Clin Proc 1985. 60538.

5. Hunder GG, Bloch DA, Michel BA, et al. The American College of Rheumatology 1990 criteria for the classification of giant cell arteritis. Arthritis Rheum 1990; 33 : 1122–8.

• Commentor: L Rohman, A Phillips - The James Cook University Hospital
• Date: Nov 18, 2011