Page 5 - Carotid and peripheral vascular interventions textbook
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                 The carotid sinus baroreceptors also reacts to changes   in the lateral and posteroanterior (PA) projections by
                 in blood vessel stretching, as well as maintaining and     angiography. Using the Bouthillier classif cation (8),
                 detecting blood pressure (BP) changes.          the ICA is divided into seven parts (C1-C7) based on the
                     It is necessary to recognize normal vascular physiology   angiographic presentation of the vessel, indicating each
                 in order to understand potential cardiovascular reactions   part providing branches into different vessels (Fig. 6-5).
                 to carotid intervention. Stretching or compression of the      •  C1: Cervical
                 carotid sinus may trigger a vasodepressor (hypotension      •  C2: Petrous
                 without bradycardia), or vasovagal (hypotension and      •  Caraticotympanic artery
                 bradycardia) response with systemic hypotension. These   •  Vidian artery
                 reactions are mediated by stimulation of the carotid        •  C3: Lacerum
                 sinus nerve (a division of the glossopharyngeal nerve)      •  C4: Cavernous
                 in the carotid baroreceptor, together with vagus nerve   •  Meningohypophyseal trunk
                 activation, which leads to inhibiting sympathetic tone.   •  Inferolateral trunk
                 The responsiveness of the carotid baroreceptors differs      •  C5: Clinoid
                 and can be affected by medication (e.g., beta-blockers and      •  C6: Ophthalmic
                 vasodilators may increase responsiveness), the occurrence   •  Ophthalmic artery
                 of calcif ed plaque within the carotid bulb (increases   •  Superior hypophyseal trunk
                 responsiveness), or prior CEA (decreases sensitivity).      •  C7: Communicating
                     The ICA provides blood to the ipsilateral eye,       •  Posterior communicating artery
                 cerebral hemispheres, and portions of the nose and       •  Anterior choroidal artery
                 forehead. In its proximal part, the ICA lies medial and   •  Anterior cerebral artery (ACA)
                 caudal to the ECA. These connections might be recognized     •  Middle cerebral artery (MCA)

                                                           C7          superior hypophyseal artery
                                   anterior choroidal artery
                                                             C6        ophthalmic artery
                                                               C5         inferior cavernous sinus
                                   Meningohypophyseal trunk               artery


                                        Carotid bulb
                                        of ICA

                 Figure 6-5. Internal carotid artery (ICA) and its branches. ACA, anterior cerebral artery; ECA, external carotid artery; MCA, middle cerebral
                 artery; PCA, posterior cerebral artery. (Adapted from Cho L, Mukherjee D. Basic cerebral anatomy for the carotid interventionalists: The intracranial
                 and extracranial vessels. Catheter Cardiovasc Interv. 2006;68:104-111.)
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