Laser Doppler Needle Probe Insertion: A Technique for Real-time Quantification of Blood Flow within the Spinal Cord in a Porcine Model

Abstract

Source: Behem, C. R. et al., Real-Time Assessment of Spinal Cord Microperfusion in a Porcine Model of Ischemia/Reperfusion. J. Vis. Exp. (2020).

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

1. Place the anesthetized and ventilated pig in right lateral position and flex the animal's back to widen the space between the vertebrae.
2. Surgically expose the paravertebral area for the preparation of spinous processes and vertebral arches (Figure 1A).
3. 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).
4. 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.
5. Carefully fix the probe with sutures (Figure 1D) and use padding to prevent dislocation or kinking of the probe.

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 aft...

Materials

List of materials used in this article

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