The haemodynamic effect of internal carotid artery stenosis on cerebral perfusion during aortic surgery

Objectives: to determine the impact of the csf,extracranial internal caroti d stenosis oil cerebral perfusion during aortoiliac surgery. Design: prospective study. Material and methods: of 432 consecutive patients undergoing aortoiliac rec onstruction, 16/86 (18%) with > 70% internal carotid artery stenosis, under went inverted surgical timing (aortic reconstruction first and carotid enda rterectomy second). Preoperative Transcranial Doppler (TCD) with and withou t acetazolamide was used to evaluate cerebrovascular reserve capacity (CRC) . Intraoperatively, middle cerebral artery flow velocity (mean MCAv) and sy stemic blood pressure (SBP) were recorded. Results: preoperatively, all 16 patients had good CRC (increase in mean MCA v: 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 all patients with unilateral carotid disease, d eclamping had no effect on left mean MCAv despite a significant decrease of SBP (129 +/- 14 to 113 +/- 21 mmHg; p = 0.0211). In those with bilateral d isease, declamping decreased both mean MCAv: from (48 +/- 12 to 39 +/- 10 c m/s; p = 0.011) and SBP (123 +/- 26 to 111 +/- 25 mmHg; p = 0.0479). No per ioperative neurological deficit occurred. Conclusions: if CRC is normal or still effective, aortoiliac reconstruction does not impair cerebral perfusion.