title: The application of near-infrared oximetry to cerebral monitoring during aneurysm embolization: a comparison with intraprocedural angiography.
abstract: Near-infrared spectroscopy (NIRS) has been used to monitor regional cerebral oxygen saturation (rSO2) in patients at risk of cerebral desaturation during surgical and neurointerventional procedures. However, the quantitative capabilities of the method have been questioned, as has its validation compared with jugular bulb oximetry. Here, we compare NIRS data acquired during coil embolization procedures with incidence of vasospasm as detected from angiography. Thirty-two subarachnoid hemorrhage patients underwent embolization. Bilateral SomaSensor strips (Invos 4100, Somanetics) were affixed to the forehead at constant anatomic positions, avoiding frontal sinuses and scalp hair. Mean arterial pressure, SaO2, end-tidal pCO2, temperature and Hb were held within a narrow range during the procedure. Ipsilateral angiography was performed every 10 to 15 minutes. An independent neuroradiologist classified any vasospasm in the parent vessel as mild (25% baseline), moderate (50%), severe (75%), or total (100%). Of all, 15/32 (46.9%) patients developed spasm; in 2 it was severe or total. There was no significant association between World Federation of Neurological Surgeons grade and baseline rSO2 signal (either ipsilateral or contralateral to the side of the aneurysm) (P=0.598). There was no significant association between side of aneurysm and baseline rSO2 signal (P=0.243). However, episodes of angiographic spasm were strongly associated with reduction in trend ipsilateral NIRS signal (P<0.001); furthermore, the degree of spasm (especially more than 75% vessel diameter reduction) was associated with a greater reduction in same-side NIRS signal (P<0.001) (2-level random effects regression model, Stata 8.2, Stata Corp, TX). NIRS may have a useful role to play in the detection of cerebral desaturation secondary to vasospasm during neuroendovascular procedures.
authors.affiliation: Department of Clinical Neurosciences (Neurosurgery), Kings College Hospital, London, UK. robbhatia@yahoo.com
authors.forename: Robin
authors.initials: R
authors.lastname: Bhatia
authors.forename: Timothy
authors.initials: T
authors.lastname: Hampton
authors.forename: Sachin
authors.initials: S
authors.lastname: Malde
authors.forename: Ngianga-Bakwin
authors.initials: NB
authors.lastname: Kandala
authors.forename: Muna
authors.initials: M
authors.lastname: Muammar
authors.forename: Neil
authors.initials: N
authors.lastname: Deasy
authors.forename: Anthony
authors.initials: A
authors.lastname: Strong
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D002533:Cerebral Angiography; D004621:Embolization, Therapeutic; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D010092:Oximetry / Q000379:methods*; D010100:Oxygen / Q000097:blood; D019265:Spectroscopy, Near-Infrared / Q000379:methods*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D010100:Oxygen