Periprocedural monitoring with regional cerebral oxygen saturation in carotid artery stenting

Hemodynamic instability during and after carotid artery stenting (CAS) may reduce cerebral blood flow (CBF), leading to cerebral ischemia. To investigate changes in CBF in the periprocedural period, we continuously recorded the regional cerebral oxygen saturation (rSO2) using near-infrared spectroscopy. In 46 consecutive patients with carotid artery stenosis, rSO2 was continuously recorded during and after CAS. In addition, the patients underwent SPECT to evaluate a change in CBF on the next day after CAS. Introprocedural bradycardia (heart rate < 50 bpm) occurred in 21 patients (46%) including one transient cardiac arrest. Intraprocedural hypotension (systolic blood pressure < 80 mmHg) occurred in 18 patients (39%), and 16 of them showed prolonged hypotension. The rSO2 in patients with bradycardia/hypotension during CAS was significantly less than that in patients without them (p < 0.01). Moreover, the SPECT on the next day after CAS demonstrated that the ipsilateral CBF in patients with bradycardia/hypotension during CAS significantly more than that in patients without them (p < 0.05). Intraprocedural hemodynamic instability resulted in a significant decrease in rSO2, leading to a possible severe cerebral ischemia. In addition, intraprocedural bradycardia/hypotension might be related with postprodedural hyperperfusion, causing the morbidity and mortality after CAS.