Superficial temporal artery duplex ultrasonography for improved cerebral hemodynamics after extracranial-intracranial bypass surgery.
BACKGROUND
To investigate the utility of superficial temporal artery (STA) duplex ultrasonography (STDU) for evaluating the improvement of the cerebral hemodynamics after extracranial-intracranial (EC-IC) bypass.


METHODS
This study included 40 consecutive patients who underwent EC-IC bypass for occlusive disease of cerebral arteries. STDU was performed to measure the flow velocity, pulsatility index, and diameter of the operated STA before and 14 days after EC-IC bypass. Regional cerebral blood flow (rCBF) and acetazolamide (ACZ) reactivity of the ipsilateral middle cerebral artery (MCA) territory were evaluated by quantitative single-photon emission computed tomography with the ACZ challenge test. We investigated the correlation between STA flow velocity/diameter and rCBF/ACZ reactivity in the ipsilateral MCA territory.


RESULTS
Mean flow velocity (MFV; 26.3 +/- 8.8 to 55.3 +/- 16.3 cm/s, p < 0.0001) and diameter (1.57 +/- 0.24 to 2.26 +/- 0.29 mm, p < 0.0001) of the STA, and rCBF (29.1 +/- 3.1 to 35.0 +/- 6.4 ml/100 g/min, p < 0.0001) and ACZ reactivity (-0.02 +/- 0.10 to 0.28 +/- 0.21, p < 0.0001) of the MCA territory increased after EC-IC bypass compared with the baseline values. STA MFV was significantly correlated with the rCBF 14 days after EC-IC bypass (R = 0.70, p < 0.0001). A cutoff value of postsurgical STA MFV greater than 48.5 cm/s yielded the highest diagnostic accuracy (sensitivity 86%; specificity, 82%) for rCBF > or = 32 ml/100 g/min after EC-IC bypass.


CONCLUSIONS
STDU was available for evaluating postsurgical patency of the bypass flow and the rCBF of the ipsilateral MCA territory. The mean blood flow velocity of the operated STA is a highly sensitive parameter for predicting rCBF in the ipsilateral MCA territory after EC-IC bypass.
Hirai
Yuko
Y
Department of Cerebrovascular Disease, Cerebrovascular Center and Clinical Research Institute, National Hospital Organization Kyushu Medical Center, Fukuoka, Japan.
Fujimoto
Shigeru
S
Toyoda
Kazunori
K
Inoue
Tooru
T
Uwatoko
Takeshi
T
Makihara
Noriko
N
Yasumori
Kotaro
K
Ibayashi
Setsuro
S
Iida
Mitsuo
M
Okada
Yasushi
Y
D000368:Aged; D002533:Cerebral Angiography; D002560:Cerebrovascular Circulation / Q000502:physiology*; D002561:Cerebrovascular Disorders / Q000000981:diagnostic imaging* / Q000601:surgery*; D003251:Constriction, Pathologic; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging; D019635:Neurosurgical Procedures; D011446:Prospective Studies; D013699:Temporal Arteries / Q000000981:diagnostic imaging* / Q000601:surgery*; D015899:Tomography, Emission-Computed, Single-Photon; D018616:Ultrasonography, Doppler, Duplex