1. Evaluation of a new needle sharp tip during infusions on brain phantom gel.
- Author
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Orozco Grajales, Gustavo Alejandro, Casanova García, Gonzalo Fernando, García Alvarez, Jose Jaime, and Sarntinoranont, Malisa
- Subjects
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HYDROGELS , *INFUSION therapy , *BLOOD-brain barrier - Abstract
Introduction: Convection enhanced delivery (CED) is a method to bypass the blood-brain barrier and deliver amounts controlled of drugs over localized zones of the brain for the treatment of disorders and tumors. Several experimental studies have been tested in animals and agarose gels to understand the effect of different parameters on the outcome this procedure. In infusion experiments with brain of animals at higher flow rates showed backflow. Objective: The objective of this study was to evaluate whether a needle with sharp tip can reduce the backflow. Methods: Infusions tests were performed on in 0.6 % agarose hydrogel. The infusions were performed with Evans blue albumin. Two different tips were used: blunt and sharp tip with 0.36 mm outside diameter. Results: For low flow rate (0.3 and 0.5 µl/min) the backflow lengths were similar for both needle tip geometries. In contrast, for high flow rates (1 and 2 µl/min), blunt tip needles presented smaller backflow distances. The flow distributions with blunt tip were symmetric, while with sharp tip, backflow started on the side of hole in the infusions with sharp tip. Conclusions: The greater backflow distances obtained with sharp tip needle could be due to the lack of symmetry of the needle. In the process of insertion of the catheter with sharp tip, the phantom gel is compressed only on one side and produce tearing in the tissue. Different response of phantom material for each tip could explain the differences on flow distributions. [ABSTRACT FROM AUTHOR]
- Published
- 2013