Page 5 - Carotid and peripheral vascular interventions textbook

CHAPTER 6 • CAROTID ARTERY DISEASE

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)
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caudal to the ECA. These connections might be recognized • Middle cerebral artery (MCA)

ACA
MCA
C7 superior hypophyseal artery
anterior choroidal artery
C6 ophthalmic artery
PCA
C5 inferior cavernous sinus
Meningohypophyseal trunk artery
C4
C3
C2

C1

ECA
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.)