Artikel
In vivo vasospasm induction by ultrasound application in the chicken chorioallantoic membrane model
In vivo Induktion von Vasospasmen mit Hilfe von Ultraschall im CAM-Modell
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Veröffentlicht: | 4. Juni 2021 |
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Gliederung
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Objective: Cerebral vasospasm is the most investigated phenomenon in the context of aneurysmal subarachnoid hemorrhage (aSAH), its pathophysiology however is still not fully understood. Experimental models are irreplaceable for the evaluation of new drugs for vasospasm resolution. In this study, we assessed the reliability of in-vivo vasospasm induction by means of ultrasound in the chicken chorioallantoic membrane (CAM) model as an alternative to animal models.
Methods: After incubation of the fertilized chicken eggs for four days, a fenestration was performed to enable examination of the CAM. On the thirteenth day continuous wave ultrasound (3 MHz, 1 W/cm2, maximum effective area of 5 cm2) was applied on the CAM vessels for 60 seconds. The ultrasound effect on the vessels was recorded by life imaging (5 MP HD-microscope camera, Leica®). The induced vasospasms were evaluated based on the vessel diameter in a defined time interval of 10 minutes using a Fiji macro. The vessel diameter before and after the ultrasound application was measured and the relative diameter reduction was calculated.
Results: The experiment was performed on 10 embryo eggs. A first reduction of vessel diameter was observed after three minutes. The maximum reduction in vessel diameter was reached eight minutes after the ultrasound treatment (mean relative vessel diameter reduction of 46%, range 44-56%). The ultrasound-induced vasospasm was reliably reproducible in all 10 eggs. The vasospasm persisted for all ten recorded minutes post induction. Longer ultrasound application (more than 60 seconds) did not lead to an increase in vasospasm-intensity.
Conclusion: Vasospasm can be reliably induced by direct short application of low frequency ultrasound in the CAM model. This might be a suitable in-vivo model for the evaluation of drug effects on vasospasm in an experimental setting and could serve as an alternative to animal models.