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

After confirming an appropriate level of sedation in a three-month-old 40-kilogram pig, place the animal in the 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 in vertebral arches, and place a vascular 14-gauge peripheral vein catheter paramedian into the spinal cord at the level of thoracic vertebrae 13 / 14 or lumbar vertebrae 1 / 2 between two vertebral arches.

Replace the needle with the laser Doppler needle probe, and connect the probe to the designated hard- and software to test the signal quality. A stable signal with a moderate pulsatility should be observed. Carefully fix the probe with sutures, and use padding to prevent the probe from dislocating or kinking.