Properties and Storage Methods of the Stratathane-ST504 Based Neurosurgical Tumor Model: A Comprehensive Analysis

Abstract Background Constrains on neurosurgical residents work hours demand innovative teaching models to complement the traditional “in the operating room” model. Stratathane ST-504 has been proposed as a useful artificial neurosurgical tumor model. The consistency, dissectability and radioopacity of this model strongly depend on its preparation and storage. However, very little work has addressed the interplay of these properties. Hence our study was undertaken to explore the properties of ST-504, its preparation and storage and how these interactions affect its radioopacity and consistency. Methods Tumor mixture was prepared by mixing 4.5 ml of water, 1.5 ml of CT contrast medium, 2 ml of ST-504 and 0.5 mg turmeric power. The tumor mixture was either allowed to solidify yielding solid tumor blocks or was injected into an anatomic specimen to create a tumor model. Both tumor blocks and tumor model were stored at different temperature, under different storage conditions and for different time. Their volumes, CT appearance and consistency were evaluated. Results The tumor blocks stored in water or ethanol absorbed fluid resulting in enlargement and associated decrease in radiodensity and consistency. The same results were displayed by the tumor implanted in cadaveric specimen. Conclusion For any given ratio of ST-504/water, the time sequence after polymer solidification and the storage method determine the CT appearance and the consistency of the tumor block/model. When taking these properties into consideration, ST-504 based artificial tumor models can be customized for different dissection practices, from more solid (meningioma like) to less solid (schwannoma like) models.