Sacral epidural electrodes for voiding in the chronic spinal dog.

Area of Science:

• Neuroscience
• Urology
• Biomedical Engineering

Background:

• Electrical stimulation of the bladder or sacral nerves is a recognized method for bladder management in spinal cord injury (SCI) patients.
• Current electrode implantation methods can be invasive, necessitating the development of less invasive alternatives.

Purpose of the Study:

• To evaluate a modified percutaneous procedure for implanting needle electrodes in the sacral canal for bladder management.
• To determine optimal electrode placement and stimulation parameters for inducing voiding in SCI dogs.

Main Methods:

• A modified percutaneous technique was used to implant needle electrodes in the sacral canal of dogs with experimental spinal cord injury.
• Electrical stimulation was applied using various electrode arrangements and parameters after bladder reflexes recovered (3 weeks post-SCI).
• The effectiveness of stimulation was assessed by its ability to induce voiding with minimal residual urine volume.

Main Results:

• The percutaneous needle electrode implantation and subsequent stimulation were effective in inducing voiding with little residual volume.
• An optimal electrode configuration involved a single midline monopolar electrode between sacral foramina L7 and S1.
• At lower currents, lateral electrodes adjacent to sacral nerves proved more effective than midline electrodes for inducing voiding.
• Effective stimulation parameters for daily voiding included 10 pulses per second (pps), 1.5–5 mA current, 0.3 ms pulse duration, and 2–3 second stimulation periods.

Conclusions:

• A modified percutaneous needle electrode technique offers a less invasive approach for sacral nerve stimulation in SCI patients.
• Optimal electrode placement and stimulation parameters can effectively restore bladder voiding function in SCI.
• This method holds promise for improving bladder management strategies in individuals with spinal cord injury.