Laparoscopically Implanted System for Stimulation of the Hypogastric Plexus Induces Colonic Motility, Defecation, and Micturition: Experimental Study

Background. Modulation of the enteric nervous system seems to be promising in several functional colorectal disorders for which targeted, causal treatment methods do not exist. However, sacral nerve stimulation can induce undesirable muscle contraction or paresthesia. Therefore, we have developed a laparoscopic technique for implanting a neural electrode, placed directly over the pelvic autonomic nerve plexus. The aim of this experimental study was to evaluate the effect of stimulating the hypogastric plexus and pelvic nerves on inducing distal colon contraction, defecation, and micturition. Method. A total of 10 white, male healthy pigs (25-30 kg) were subjected to the laparoscopic implantation of the electrode and the stimulator. In the third and fourth weeks postimplantation, the efficacy of the acute and chronic stimulation to induce defecation was evaluated. Results. The average operative time was 105 minutes (85-150 minutes). In all pigs, acute stimulation activated induced defecation, every second day, every time on demand, with an average delay of 139.7 s. Micturition was induced incidentally. Acute or chronic stimulation did not cause any harm, pain, or suffering to the animals. No adverse effects of the stimulation were observed, and no septic complications or macroscopic fibrosis around the electrodes were found on autopsy. Conclusion. Hypogastric plexus stimulation can be a useful and safe option of distal colon contraction, defecation, and micturition. However, the efficacy of the stimulation was observed for a relatively short period of time, and it is not known if it will be sustained for a longer duration.