Temporal Artery BiopsyRaed Behbehani , MD FRCSCGiant Cell ArteritisThe most important medical ophthalmic emergency.

Why TAB ?Early recognition and initiation of steroid treatment for a sufficient duration,Treatment (systemic steroids) is associated with high risk of morbidity.Steroids is double-edged swordDuhaut P et al. Biopsy proven and biopsy negative temporal arteritis: differences in clinical spectrum at the onset of the disease. Ann Rheum Dis 1999Series of 207 biopsy-proven and 85 biopsy-negative GCA cases. Potentially iatrogenic steroid complications might explain up to 20% of the observed deaths in their study group.ACR Criteria for GCAAge 50 years or older

New-onset localized headacheTemporal artery tenderness or decreased temporal arterypulse,Erythrocyte sedimentation rate (ESR) of at least50 mm/hour, Abnormal artery biopsy specimen characterized by mononuclear infiltration or granulomatous inflammation.3 of 5 Sensitivity of 93.5% and specificity of91.2% for the classification of GCA compared with othervasculitidesTABACR criteria differentiate patients who have vasculitis from those who do not have vasculitis for diagnostic purposes.ACR Diagnostic criteria to identify a patient with GCA is better when the prevalence is high (e.g. Rheumatology clinic).TAB vs ACR Criteria (Murchison AP et al, Am J Ophth 2012)Twenty five percent of patients who had a positive biopsy did not meet ACR criteria.Twenty eight percent of patients who met ACR criteria did not have a positive biopsy.Occult GCATwenty percent of GCA patients have only visual symptoms (Occult GCA) - Transient visual loss , transient diplopia (Simmons RJ, Cogan DG. Occult temporal arteritis. Arch Ophthalmol 1962)GCA Diagnosis ESR , CRPPlateletsInterleukin 8 Color DuplexUnilateral vs BilateralDanesh-Meyer HV et al . J Neuroophthalmology 2000In 90 (99%) of the 91 patients, the histologic diagnoses in the left and right superficial temporal arteries were the same. A concordance rate of 98.9% (38 of 39 positive biopsy results) Low yield in obtaining a biopsy on the contralateral side.How long is enough ?Murchison AP et al. Ophthal Plast Reconstr Surg. 2012 Review of 62 TAB biopsy specimens.4.61-mm mean shrinkage with 2.97-mm standard deviationA 27.58-mm specimen would have to be obtained to consistently get 20 mm length specimenIndication of TABAny patient who with clinical signs and symptoms of GCA.Biopsy should be performed if clinical suspicion is high regardless of laboratory results. Superficial Temporal Artery

STA Anatomy

TechniquePalpation is critical.Hand-held doppler. Consider using local anesthetic without epinephrine to avoid artery vasoconstriction.Technique

Use a hemostat for wide dissection of superficial temporal fasciaTechnique

Sharp dissection through the Superficial temporal fascia Technique

* 4.0 Silk traction sutures passed below artery for traction* Sharp and blunt dissection around the arteryTechnique

At least 2 cm segment is preferableIntraoperative Predictability of Temporal Artery Biopsy ResultsCetinkaya, Altug M.D at al. Ophthalmic Plastic & Reconstructive Surgery, 2012

A. Nodular, thickened artery that appears pale throughout the entire section->grossly positive, B. The lumen is completely occluded. No back-bleeding from anastomotic branches during dissection.

Technique

Skin closure is with running baseball or vertical mattress with 6.0 non-absorbable suturesTechnique

Complications of TABBrow ptosis Wrong biopsy (vein or nerve)Bleeding/echymosisStroke ( extremely rare)Brow Ptosis Injury to upper temporal branch of facial nerve.Facial nerve runs deep to temporal branch of STA beneath the fascia.Avoid dissection very deep to artery and fascia.Dont dissect close to lateral orbital rim or brow.Brow Ptosis

danger zone: contains temporal branches traveling superficially and therefore presumably more susceptible to injury. Scott KR et al. Temporal artery biopsy technique: a clinico-anatomical approach. Ophthalmic Surg 1991.

Safety LineSafety line: from the tragus to a point 2.0 cm from the most lateral brow cilia.

2 cmBrow Ptosis after Temporal Artery Biopsy Incidence and Associations Ann P. Murchison et al. Ophthalmology 2012

Only 1 of 35 patients with incision > 35 mm from brow developed brow ptosisBrow Ptosis

Ann P. Murchison et al. Ophthalmology 2012One weekSix monthsWrong biopsy Artery has a thicker wall smaller in diameter and is whiter than a vein.Hematoma

Ann P. Murchison et al. Ophthalmology 2012StrokeExtremely rare.In case if severely narrowed ICA since there areas of anastomosis between ICA supraorbital artery) and ECA (STA).Wound DehiscenceCan be avoided by meticulous skin closure technique.SummaryTAB is an easy , low-risk procedure to confirm GCA diagnosis (gold-standard).Good communication with the pathologist is important.Complications (brow ptosis) can be minimized by careful technique.