Stratification of intraoperative ischemic impact by somatosensory evoked potential monitoring, diffusion-weighted imaging and magnetic resonance angiography in carotid endarterectomy with routine shunt use
- 322 Downloads
Routine shunting to minimize ischemia during carotid endarterectomy (CEA) is controversial. The aim of this study was to stratify the ischemic parameters associated with CEA and evaluate the effect of routine shunting in attempting to mitigate those ischemia.
Data from 248 CEAs with routine shunting were retrospectively evaluated. Our assessment included somatosensory evoked potential (SSEP) amplitude reduction more than 50 % and longer than 5 min (SSEP<50%, >5 min), new postoperative diffusion-weighted imaging lesions (new DWI lesions), and severe stenosis as indicated by reduced ipsilateral middle cerebral artery (MCA) signal on preoperative magnetic resonance angiography (MRA asymmetry), as surrogates of hypoperfusion, microembli, and hemodynamic impairment, respectively.
SSEP<50%, >5 min occurred in 15 % of CEAs during cross-clamping, and shunting reversed the SSEP changes. New DWI lesions were observed in 4.1 %. Pre-clamping the common and external carotid artery during dissection (pre-clamp method) decreased the rate of new DWI lesions compared to without pre-clamping (3.5 % vs. 7.5 %, P = 0.22). Occlusion time was significantly longer in the pre-clamp method than without pre-clamping (P < 0.0001). However, the incidence of SSEP<50%, >5 min was not increased with the pre-clamp method (p = 1.0) when using information regarding SSEP and collaterals to modify the speed of shunt manipulation. MRA asymmetry was identified in 39 CEAs (15.8 %) with correction of asymmetry postoperatively. MRA asymmetry correlated with symptomatic hyperperfusion (P = 0.0034). Only three CEAs had symptomatic hyperperfusion (1.2 %) with minimal symptoms. Ten CEAs sustained transient ischemia, symptomatic hyperperfusion, or 30-day-stroke (composite postoperative ischemic symptoms). Logistic regression analysis confirmed that SSEP<50%, >5 min (p = 0.009), new DWI lesions (p = 0.004) and MRA asymmetry (p = 0.042) were independent predictors of composite postoperative ischemic symptoms.
SSEP<50%, >5 min, new DWI lesions, and MRA asymmetry were able to stratify the ischemic impacts in CEA. Meticulous routine shunting could mitigate those appropriately.
KeywordsCarotid endarterectomy Cerebral ischemia Diffusion-weighted imaging Magnetic resonance angiography Shunt Somatosensory evoked potentials
Common carotid artery
Computed tomographic angiography
Digital subtraction angiography
External carotid artery
Internal carotid artery
Middle cerebral artery
Magnetic resonance angiography
Magnetic resonance imaging
Single photon emission computed tomography
Somatosensory evoked potentials
Superficial temporal artery
Transient ischemic attack
Conflicts of interest
Video clip showing CEA with the pre-clamp method. (MPG 30988 kb)
- 11.Feliziani FT, Polidori MC, Rango PD, Mangialasche F, Monastero R, Ercolani S, Raichi T, Cornacchiola V, Nelles G, Cao P, Mecocci P (2010) Cognitive performance in elderly patients undergoing carotid endarterectomy or carotid artery stenting: a twelve-month follow-up study. Cerebrovasc Dis 30:244–251PubMedCrossRefGoogle Scholar
- 13.Gaunt ME, Martin PJ, Smith JL, Rimmer T, Cherryman G, Ratliff DA, Bell PRF, Naylor AR (1994) Clinical relevance of intraoperative embolization detected by transcranial Doppler ultrasonography during carotid endarterectomy: a prospective study of 100 patients. Br J Surg 81:1435–1439PubMedCrossRefGoogle Scholar
- 18.Heyer EJ, DeLaPaz R, Halazum HJ, Rampersad A, Sciacca R, Zurica J, Benvenisty AI, Quest DO, Todd GJ, Lavine S, Solomon RA, Connolly ES (2006) Neuropsychological dysfunction in the absence of structural evidence for cerebral ischemia after uncomplicated carotid endarterectomy. Neurosurgery 58:474–480PubMedCrossRefGoogle Scholar
- 20.Hirooka R, Ogasawara K, Inoue T, Fujiwara S, Sasaki M, Chida K, Ishigaki D, Kobayashi M, Nishimoto H, Otawara Y, Tsushima E, Ogawa A (2009) Simple assessment of cerebral hemodynamics using single-slab three dimensional time-of-flight magnetic resonance angiography in patients with quantitative perfusion single-photon emission computed tomography. AJNR Am J Neuroradiol 30:559–563PubMedCrossRefGoogle Scholar
- 23.Kawamata T, Okada Y, Kawashima A, Yoneyama T, Yamaguchi K, Ono Y, Hori T (2009) Postcarotid endarterectomy cerebral hyperperfusion can be prevented by minimizing intraoperative cerebral ischemia and strict postoperative blood pressure control under continuous sedation. Neurosurgery 64:447–454PubMedCrossRefGoogle Scholar
- 24.Kuroda H, Ogasawara K, Hirooka R, Kobayashi M, Fujiwara S, Chida K, Ishigaki D, Otawara Y, Ogawa A (2009) Prediction of cerebral hyperperfusion after carotid endarterectomy using middle cerebral artery signal intensity in preoperative single-slab 3-dimensional time-of-flight magnetic resonance angiography. Neurosurgery 64:1065–1072PubMedCrossRefGoogle Scholar
- 27.Mazul-Sunko B, Hromatko I, Tadinac M, Sekulić A, Ivanec Ž, Gvozudenović A, Tomašević B, Gavranović Z, Maladić-Batinica I, Čima A, Vrkić N, Lovričević I (2010) Subclinical neurocognitive dysfunction after carotid endarterectomy—the impact of shunting. J Neurosurg Anesthesiol 22:195–201PubMedCrossRefGoogle Scholar
- 40.Wolf O, Heider P, Heinz M, Poppert H, Sander D, Greil O, Weiss W, Hanke M, Eckstein H (2004) Microembolic signals detected by transcranial Doppler sonography during carotid endarterectomy and correlation with serial diffusion-weighted imaging. Stroke:e373–e375Google Scholar