De novo ivy sign indicates postoperative hyperperfusion in moyamoya disease.
OBJECTIVE
The ivy sign on fluid-attenuated inversion recovery MRI is a specific finding in moyamoya disease (MMD). This sign indicates decreased cerebral perfusion, dilated pial vasculature, and slow leptomeningeal collateral flow. This study aimed to clarify the characteristics of perioperative changes in the ivy sign in relation to cerebral hyperperfusion, which frequently occurs in MMD of unknown pathogenesis.


METHODS
This prospective study included patients with MMD who underwent superior temporal artery-middle cerebral artery single bypass. Fluid-attenuated inversion recovery MRI was performed to evaluate the appearance of the ivy sign in the ipsilateral hemisphere preoperatively and on postoperative days 2 and 30. The ivy sign was assessed in combination with perioperative symptoms and cerebral hemodynamics using single-photon emission computed tomography.


RESULTS
Of 42 consecutive patients (55 sides) who underwent bypass surgery, 32 (58.2%) showed an increase in the ivy sign (de novo ivy sign) on postoperative day 2; this had disappeared by day 30. Interestingly, these 32 patients had a significantly higher incidence of hyperperfusion on single-photon emission computed tomography and hyperperfusion syndrome, and there was no correlation between the de novo ivy sign and a preoperative ivy sign or the preoperative cerebral hemodynamics. In multivariate analysis, a de novo ivy sign was significantly correlated with postoperative hyperperfusion.


CONCLUSIONS
In MMD, a de novo ivy sign could indicate postoperative hyperperfusion after bypass, which is not always correlated with preoperative hemodynamic impairment. Additional factors other than preoperative cerebral hemodynamics might be involved in postoperative hyperperfusion in MMD.
From the Departments of Neurosurgery (N.H., Y.M., T.H., T.I., K.H., I.N.) and Radiology (M.M.), Nagasaki University School of Medicine, Nagasaki, Japan.
Nobutaka
N
Horie
Minoru
M
Morikawa
Youichi
Y
Morofuji
Takeshi
T
Hiu
Tsuyoshi
T
Izumo
Kentaro
K
Hayashi
Izumi
I
Nagata
D002548:Cerebral Revascularization / Q000009:adverse effects* / Q000379:methods; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D020768:Middle Cerebral Artery / Q000601:surgery; D009072:Moyamoya Disease / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D011183:Postoperative Complications / Q000473:pathology / Q000503:physiopathology*; D011446:Prospective Studies; D013699:Temporal Arteries / Q000601:surgery; D015899:Tomography, Emission-Computed, Single-Photon; D016896:Treatment Outcome
moyamoya disease