Direct bladder stimulation with suture electrodes promotes voiding in a spinal animal model: a technical report

Area of Science:

• Biomedical Engineering
• Neuroscience
• Urology

Background:

• Direct bladder stimulation is a potential therapeutic approach for bladder dysfunction.
• Assessing novel electrode efficacy and safety is crucial for clinical translation.

Purpose of the Study:

• To evaluate the efficacy and safety of a new stainless-steel wire electrode for direct bladder stimulation.
• To determine optimal stimulation parameters for inducing bladder contractions and voiding.
• To assess the electrode's performance in a spinal cord injury (SCI) model.

Main Methods:

• Five male cats were surgically implanted with novel wire electrodes on the bladder serosa.
• Bladder function was assessed via pressure recording, filling, and electromyography (EMG) of leg and pelvic floor muscles.
• A T-1 level spinal cord complete lesion was induced to create an SCI model.

Main Results:

• Direct bladder stimulation successfully induced active bladder contractions and voiding in cats both before and after SCI.
• Voiding rates improved more than two weeks post-SCI and at larger initial bladder volumes.
• Optimal stimulation parameters were identified (40 Hz, 300 µs–1 ms pulse duration, 3–4 s stimulation, 10–40 mA).
• No adverse effects on urethral function were observed, with fluoroscopy confirming an open urethra during stimulation and voiding.
• The implanted electrodes showed no signs of corrosion, erosion, or dislodgement, indicating chronic implantation suitability.

Conclusions:

• The novel suture electrode is effective for direct bladder stimulation, inducing voiding in cats.
• The electrode technology shows promise for managing bladder dysfunction, including in SCI patients.
• The electrode material and design are suitable for chronic implantation without adverse effects.