Novel application of near-infrared spectroscopy in detecting iatrogenic vasospasm during interventional neuroradiological procedures.

One of the complications of carotid artery stenting (CAS) is iatrogenic vasospasm caused by mechanical irritation of the blood vessel lumen by a guidewire, catheter, stent retriever, or distal protection devices. Although often self-limiting, the mechanical vasospasm can cause reduction in the cerebral blood flow and result in catastrophic ischemia, especially when undetected and persistent. Real-time cerebral oximetry with near-infrared spectroscopy (NIRS) could detect episodes of cerebral hypoxemia due to vasospasm and facilitate intervention for prevention of hypoxic brain injury during neuro-intervention procedures such as CAS. We present a case scenario where NIRS detected iatrogenic vasospasm even before the conventional tests could identify the event during CAS.