Improvement in the Retinal Circulation after Superficial Temporal to Middle Cerebral Artery Bypass

Abstract

The retinal circulation of 35 patients (age, 30 to 71 years) with symptomatic internal carotid occlusion (22 cases) or severe inaccessible stenosis (13 cases) was studied both before and after superficial temporal to middle cerebral artery (STA-MCA) bypass surgery using ophthalmodynamometry (ODM) and intravenous fundus fluorescein angiography (IVFA). Ninety-four per cent of the patients were found preoperatively to have funduscopic findings or symptoms indicative of ocular ischemia. ODM values were abnormal preoperatively in 32 of 35 patients (91%), and improvement in ODM values for the ipsilateral eye was noted postoperatively in 25 patients (71%). ODM values obtained during the early (less than 3 months) and late (greater than 3 months) postoperative periods were significantly improved when compared to the preoperative values. IVFA values were abnormal in 25 of 29 patients (86%) preoperatively, and significant improvement was noted in 22 of 25 patients (88%) postoperatively. Preoperative patients with normal fundus examinations (10 cases) had significantly better values for IVFA and ODM than patients with venous stasis retinopathy. The findings of the study showed that STA-MCA anastomosis is beneficial in treating retinal ischemia secondary to ipsilateral severe inaccessible carotid artery stenosis or occlusion.

Chronic ocular ischaemia

“…Sarkies et d. (1987) showed improvement in the microcirculation of the retina in 4 cases after carotid endarterectomy and in 1 case after carotid endarterectomy and extracranial-intracranial bypass. The same beneficial results were reported by Standefer et al (1985) after superficial temporal to middle cerebral artery bypass surgery.…”

Guidelines for the management of transient ischemic attacks. From the Ad Hoc Committee on Guidelines for the Management of Transient Ischemic Attacks of the Stroke Council of the American Heart Association.

“…Newer imaging techniques such as positron emission tomography, single photon emission computed tomography, or xenon CT have been used to identify patients with inadequate hemodynamic reserve who might respond to extracranial/intracranial bypass.169'170 However, a recent clinical series in which positron emission tomography was used failed to identify such a group.17' Studies have provided level IV and V evidence for a possible use for bypass procedures for patients with moyamoya disease'72'173 and retinal ischemia. [174][175][176] More randomized clinical trials are needed before bypass surgery can be recommended for these patients.…”

OODG-Ulrich and OPG-Gee: a comparative study

“…In order to diagnose hemodynamically determined ophthalmological syndromes in carotid stenoses as well as for the assessment of the effect of carotid artery desobstruction and extra-intracranial (EC-IC) arterial bypass surgery on the vascular state of the eye, measurement of the ophthalmic blood pressure is either recommended or executed [3,29,30,31].…”