Analysis of cerebral perfusion and metabolism assessed with positron emission tomography before and after carotid artery stenting. Clinical article.
OBJECTIVE
The authors analyzed cerebral perfusion and metabolism in patients with internal carotid artery stenosis before and after carotid artery stenting (CAS).


METHODS
Sixteen patients with internal carotid artery stenosis (>70%) underwent PET scanning before CAS, 1-7 days after CAS, and 3-4 months after CAS to assess a variety of parameters related to cerebral perfusion and metabolism.


RESULTS
Cerebral blood flow at rest (CBFrest) significantly increased in the immediate postoperative stage before returning to normal levels over the long term; this trend was also recognized on the contralateral side. In contrast, there was gradual improvement in the rate of CBF variation on acetazolamide administration (% CBFaz). Cerebral perfusion pressure (CBF/cerebral blood volume) increased rapidly during the acute stage and decreased in the long term, and the oxygen extraction fraction decreased slightly during the acute stage before normalizing over the long term. The cerebral metabolic rate of oxygen (CMRO2) increased slightly after stenting over both the short and long term. The ratios of ipsilateral to contralateral values (asymmetry index) for CBFrest, % CBFaz, cerebral blood volume, oxygen extraction fraction, and CMRO2 tended to approach 1.0 over time.


CONCLUSIONS
Repeated PET scanning revealed improvements in CBF, perfusion pressure, and oxygen metabolism after CAS. In particular, the vascular reserve tended to improve gradually, while CBF, cerebral perfusion pressure, and CMRO2 increased rapidly and peaked soon after CAS. These results suggest that a large discrepancy between rapidly increased CBF, perfusion pressure, and a small increase in vascular reserve in the acute stage after CAS could cause hyperperfusion syndrome.
Matsubara
Shunji
S
Department of Strokology, Research Institute for Brain and Blood Vessels-Akita, Akita, Japan.
Moroi
Junta
J
Suzuki
Akifumi
A
Sasaki
Masahiro
M
Nagata
Ken
K
Kanno
Iwao
I
Miura
Shuichi
S
D000208:Acute Disease; D000368:Aged; D001810:Blood Volume; D001921:Brain / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000378:metabolism; D002339:Carotid Arteries / Q000000981:diagnostic imaging / Q000502:physiology; D016893:Carotid Stenosis / Q000000981:diagnostic imaging* / Q000628:therapy*; D002533:Cerebral Angiography; D002560:Cerebrovascular Circulation; D005260:Female; D007839:Functional Laterality; D006801:Humans; D010100:Oxygen / Q000378:metabolism; D049268:Positron-Emission Tomography; D011300:Preoperative Care; D015607:Stents
D010100:Oxygen