The Haemodynamic Effect of Internal Carotid Artery Stenosis on Cerebral Perfusion During Aortic Surgery

Objectives: to determine the impact of the extracranial internal carotid stenosis on cerebral perfusion during aortoiliac surgery. Design: prospective study. Material and methods: of 432 consecutive patients undergoing aortoiliac reconstruction, 16/86 (18%) with >70% internal carotid artery stenosis, underwent inverted surgical timing (aortic reconstruction first and carotid endarterectomy second). Preoperative Transcranial Doppler (TCD) with and without acetazolamide was used to evaluate cerebrovascular reserve capacity (CRC). Intraoperatively, middle cerebral artery flow velocity (mean MCAv) and systemic blood pressure (SBP) were recorded. Results: preoperatively, all 16 patients had good CRC (increase in mean MCAv: 66% right and 72% left). Intraoperatively, the mean MCAv (from 49±13 to 45±14 cm/s; p=0.0249) and SBP decreased (from 127±25 to 113±22 mmHg; p= 0.0016). In patients with unilateral carotid disease, declamping had no effect on left mean MCAv despite a significant decrease of SBP (129±44 to 113±21 mmHg; p=0.0211). In those with bilateral disease, declamping decreased both mean MCAv: from (48±12 to 39±10 cm/s; p=0.011) and SBP (123±26 to 111±25 mmHg; p=0.0479). No perioperative neurological deficit occurred. Conclusions: if CRC is normal or still effective, aortoiliac reconstruction does not impair cerebral perfusion.