Usefulness of somatosensory-evoked potentials for monitoring cerebral perfusion during transcarotid transcatheter aortic valve replacement: a case report.

BACKGROUND: Transcarotid transcatheter aortic valve replacement (TAVR) is a safe procedure with a low incidence of cerebral infarction and has recently become the first-choice alternative approach. This procedure requires temporary occlusion of the common carotid artery (CCA). CCA clamping during surgery may help reduce the risk of embolism caused by debris; however, the risk of hemodynamic stroke cannot be entirely ruled out. Therefore, intraoperative monitoring of cerebral ischemia is essential. Regional oxygen saturation (rSO2) monitoring is commonly used, but can only measure local mixed venous oxygen saturation in the frontal lobes. During carotid endarterectomy (CEA), a combination of multiple monitoring methods for intraoperative cerebral ischemia is recommended. Similarly, we used somatosensory-evoked potentials (SEPs) in conjunction with rSO2 monitoring.

CASE PRESENTATION: A 92-year-old male patient with a history of dyspnea on exertion was diagnosed with severe aortic valve stenosis (AS) using transthoracic echocardiography (TTE). Contrast-enhanced computed tomography (CT) revealed a shaggy aorta extending from the aortic arch to the descending aorta. Preoperative magnetic resonance angiography (MRA) of the head showed slight narrowing of the anterior communicating artery. Considering the patient's age, frailty, and vascular pathology, we performed transcarotid TAVR while monitoring rSO2 and SEPs for intraoperative cerebral ischemia. No significant decreases in rSO2 values or SEPs amplitudes due to occlusion of the left CCA. The procedure was successful, with no postoperative stroke, and the patient had an uneventful recovery.

CONCLUSIONS: In transcarotid TAVR requiring CCA occlusion, monitoring cerebral ischemia with both rSO2 and SEPs may help prevent perioperative hemodynamic cerebral infarction.