The current guidelines are far from being complete or over-encompassing, but these limita­tions should never diminish the role of the large and randomized studies when compared to individual or center’s experience. On the other hand, the clinical practicality that is built on the baseline offered by the guidelines can and should go beyond these, when backed by a thorough motivation. Decisions are sometimes diffi cult to take, as numerous variables not only enrich but also complicate the clinical picture in the individual patient. Some of the most important factors to be taken into account and, not least, some of the limitations of the current protocols and guidelines are synthetically presented below.

differences emerge and practical measures appear quite different. The degree of carotid steno­sis cannot be considered as an absolute criterion for the therapeutic indication, when consider­ing even the pure, anatomical individual variations of the aortic arch and of the neck vessels. 6 Bilateral carotid stenotic disease is associated with multi-territorial arterial disease and with a higher risk of non-stroke death. 7 A more aggressive medical therapy is warranted and other types of surgery are also indicated, for example, the simultaneous bilateral carotid endarterec­tomy (SBCE). Many of the lesions in one of the vertebral arteries (VA) are overlooked, as the common opinion is that the opposite VA will compensate for the diseased one. Embolism or extension of thrombosis from the diseased VA represents important causes of stroke in the vertebrobasilar system. The highly stenotic or occluded VA may steal blood from the carotid system (even when the subclavian artery is not occluded). The variations in the intracerebral distribution of the major cerebral trunks and of the arterial circle of Willis and its emerging branches are additional variables in the therapeutic algorithm. Comorbidities and the extant of atherosclerotic disease impose a thorough and a highly individualized strategy and a decision which is not always easy to take.

A1-A3 Segments of the anterior cerebral artery (1 through 3) ACA Anterior cerebral artery ACommA Anterior communicating artery ARSA Aberrant right subclavian artery (retroesophageal subclavian, “arteria lusoria”) ASM Anterior scalene muscle BA Basilar artery BBB Blood-brain barrier BCT Brachiocephalic trunk (“innominate artery” ) C 1 -C 7 Cervical vertebrae (1 through 7) C1-C7 Segments of the internal carotid artery CAM Cell adhesion molecules CAS Carotid angioplasty and stenting CCA Common carotid artery CEA Carotid endarterectomy CETP Cholesteryl ester transfer protein CHS Cerebral hyperperfusion syndrome CoW Arterial circle (circle of Willis) CSF Cerebrospinal fl uid CT Computerized tomography CT-angio Computerized tomographic angiography CVD Cardiovascular disease DSA Digital subtraction angiography EC Endothelial cells ECA External carotid artery HA Hypoglossal artery HDL High-density lipoprotein ICA Internal carotid artery ICH Intracerebral (intraparenchymal) hemorrhage IFN Interferon(s) IJV Internal jugular vein IL Interleukins MCP Monocyte chemoattractant protein mLDL Modifi ed low-density lipoproteins MMPs Matrix metalloproteinases MRA Magnetic resonance angiography MRI Magnetic resonance imaging OA Otic artery P1-P3 Segments of the posterior cerebral artery (1 through 3) PCA Posterior cerebral artery PCommA Posterior communicating artery ProA Proatlantal artery PTFE Polytetrafl uoroethylene vascular graft