Эпидуральная внутричерепного Измерение давления у крыс с помощью волоконно-оптических преобразователей давления
Summary
Новый метод для записи давления внутри черепа описано. Малоинвазивных методов используются волоконно-оптические системы измерения давления для точного измерения внутричерепного давления (ВЧД) в анестезии крыс без причинения значительного травмы головного мозга. Методика может быть использована в широком диапазоне экспериментальных моделей.
Abstract
Elevated intracranial pressure (ICP) is a significant problem in several forms of ischemic brain injury including stroke, traumatic brain injury and cardiac arrest. This elevation may result in further neurological injury, in the form of transtentorial herniation1,2,3,4, midbrain compression, neurological deficit or increased cerebral infarct2,4. Current therapies are often inadequate to control elevated ICP in the clinical setting5,6,7 . Thus there is a need for accurate methods of ICP measurement in animal models to further our understanding of the basic mechanisms and to develop new treatments for elevated ICP.
In both the clinical and experimental setting ICP cannot be estimated without direct measurement. Several methods of ICP catheter insertion currently exist. Of these the intraventricular catheter has become the clinical ‘gold standard’ of ICP measurement in humans8. This method involves the partial removal of skull and the instrumentation of the catheter through brain tissue. Consequently, intraventricular catheters have an infection rate of 6-11%9. For this reason, subdural and epidural cannulations have become the preferred methods in animal models of ischemic injury.
Various ICP measurement techniques have been adapted for animal models, and of these, fluid-filled telemetry catheters10 and solid state catheters are the most frequently used11,12,13,14,15. The fluid-filled systems are prone to developing air bubbles in the line, resulting in false ICP readings. Solid state probes avoid this problem (Figure 1). An additional problem is fitting catheters under the skull or into the ventricles without causing any brain injury that might alter the experimental outcomes. Therefore, we have developed a method that places an ICP catheter contiguous with the epidural space, but avoids the need to insert it between skull and brain.
An optic fibre pressure catheter (420LP, SAMBA Sensors, Sweden) was used to measure ICP at the epidural location because the location of the pressure sensor (at the very tip of the catheter) was found to produce a high fidelity ICP signal in this model. There are other manufacturers of similar optic fibre technologies13 that may be used with our methodology. Alternative solid state catheters, which have the pressure sensor located at the side of the catheter tip, would not be appropriate for this model as the signal would be dampened by the presence of the monitoring screw.
Here, we present a relatively simple and accurate method to measure ICP. This method can be used across a wide range of ICP related animal models.
Protocol
Discussion
Процедуры, представленные здесь дает очень чувствительный и точный учет внутричерепного давления. Это малоинвазивная методика позволяет избежать значительных травм мозга, поместив датчик давления в эпидуральном пространстве, а не ткани мозга или желудочков.
Важные ш?…
Declarações
The authors have nothing to disclose.
Acknowledgements
Этот проект финансируется Национальным фондом инсульта, Хантер Института медицинских исследований (HMRI) и Национального Здоровья и Медицинского исследовательского совета (NH и MRC), Австралия. Особая благодарность факультет Медицинский персонал семинар в Университете Ньюкасла своих технических знаний.
Materials
| Name of the reagent | Company | Catalogue number | Comments |
| Dental Cement Monomer | Henry Schein | VX- SC500MLL | |
| Dental Cement Polymer | Henry Schein | VX- SC1000GCL4 | |
| Dental drill burr- size 12 | Gunz Dental | EL104S001012/10 | |
| Dental drill burr- size 6 | Gunz Dental | EL104S001006/10 | |
| Metal Screw | Hardware Store | 2 x 4 mm, hexagonal head. (laboratory-modified by 0.7 mm hole drilled through shaft) | |
| SAMBA Control Unit | Harvard Apparatus | 50433102 | |
| SAMBA Sensor | Harvard Apparatus | 50461122 | 420 LP, 15cm bare fibre, radio-opaque coating |
| Silagum AV Mono caulking material | Gunz Dental | RG 9152 | Vinylpolysiloxanes, hydrogen polysiloxanes, filler, pigments, additives, plantinum catalyst |
| Terg-A-Zyme | Alconox, Inc. | 1304 | Enzyme-active powdered detergent |
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