Notes

Internal Carotid Artery

Sections

INTERNAL CAROTID ARTERY

Internal Carotid Artery

Bouthillier's 1996 classification scheme

Cervical segment

  • Ascends from the carotid bifurcation through the carotid space to the carotid canal.

Petrous segment

  • Rises and passes forward within the carotid canal.

Lacerum segment

  • Exits the carotid canal and rises to the cavernous sinus.

Cavernous sinus segment

  • Rises within the cavernous sinus, then passes forward through it, and then rises out of the cavernous sinus, where it becomes the clinoid segment.

Clinoid segment

  • Curves posteriorly.

Ophthalmic segment

  • Passes posteriorly and gives off the ophthalmic artery, which traverses anteriorly through the optic canal.

Communicating segment

AAN Practice Parameter

  • Carotid endarterectomy—An evidence-based review Report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology. Neurology September 27, 2005 vol. 65 no. 6 794-801
    Reaffirmed on February 9, 2008 and April 30, 2014.

Conclusions

  • Evidence supports carotid endarterectomy for severe (70 to 99%) symptomatic stenosis (Level A).
  • Endarterectomy is moderately useful for symptomatic patients with 50 to 69% stenosis (Level B) and not indicated for symptomatic patients with <50% stenosis (Level A).
  • For asymptomatic patients with 60 to 99% stenosis, the benefit/risk ratio is smaller compared to symptomatic patients and individual decisions must be made.
  • Endarterectomy can reduce the future stroke rate if the perioperative stroke/death rate is kept low (<3%) (Level A). * Low dose aspirin (81 to 325 mg) is preferred for patients before and after carotid endarterectomy to reduce the rate of stroke, myocardial infarction, and death (Level A).