Overview
This video demonstrates the placement of a laser Doppler needle probe in the spinal cord of a porcine model. This helps in the continuous quantification of blood supply to the spinal cord, an important assessment in spinal cord injury.
Protocol
All procedures involving animal models have been reviewed by the local institutional animal care committee and the JoVE veterinary review board.
1. Probe placement
- Place the anesthetized and ventilated pig in right lateral position and flex the animal's back to widen the space between the vertebrae.
- Surgically expose the paravertebral area for the preparation of spinous processes and vertebral arches (Figure 1A).
- Place a vascular 14 G peripheral vein catheter paramedian into the spinal cord at the level of thoracic vertebra (Th) 13/14 or lumbar vertebra (L) 1/2 between two vertebral arches (Figure 1B).
- Remove the needle, insert the laser/Doppler needle probe over the vein catheter (Figure 1C), and test the signal quality by connection to the designated hard- and software. Ensure that there is a stable signal with moderate pulsatility.
- Carefully fix the probe with sutures (Figure 1D) and use padding to prevent dislocation or kinking of the probe.
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Representative Results
Figure 1: Placement of laser/Doppler needle probe in the spinal cord. (A) Surgical exposure of vertebral structures. (B) Puncture of the spinal cord using a vein catheter. (C) Insertion of the needle probe after removal of the inlay needle. (D) Fixation of the needle probe.
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Materials
| Name | Company | Catalog Number | Comments |
| Infinity Delta | Dräger Medical, Lübeck, Germany | Basic Monitoring Hardware | |
| Infinity Hemo | Dräger Medical, Lübeck, Germany | Basic Pressure Monitoring and Pulmonary Thermodilution Hardware | |
| LabChart Pro | ADInstruments Ltd., Oxford, UK | v8.1.16 | Synchronic Laser-Doppler, Blood Pressure, ECG and Blood-Flow Aquisition Software |
| moor VMS LDF | moor Instruments, Devon, UK | Designated Laser-Doppler Hardware | |
| moor VMS Research Software | moor Instruments, Devon, UK | Designated Laser-Doppler Software | |
| PiCCO 2, Science Version | Getinge AB, Göteborg, Sweden | v. 6.0 | Blood Pressure and Transcardiopulmonary Monitoring Hard- and Software |
| PowerLab | ADInstruments Ltd., Oxford, UK | PL 3516 | Synchronic Laser-Doppler, Blood Pressure, ECG and Blood-Flow Aquisition Hardware |
| QuadBridgeAmp | ADInstruments Ltd., Oxford, UK | FE 224 | Four Channel Bridge Amplifier for Laser-Doppler and Invasive Blood Pressure Aquisition |
| Twinwarm Warming System | Moeck & Moeck GmbH, Hamburg, Germany | 12TW921DE | Warming System |
| VP 3 Probe, 8mm length (individually manufactured) | moor Instruments, Devon, UK | Laser-Doppler Probe | |
| Zeus | Dräger Medical, Lübeck, Germany | Anesthesia Machine |
