In selected patients with chronic non-obstructive urinary retention, sacral neuromodulation (SNM) offers an important therapeutic alternative to self-catheterization. Neuromodulation is used by employing chronic nerve root stimulation. The aim of our work is to evaluate the patient's self-directed stimulation by switching on the pulse generator 15 - 20 minutes before each urination.

We assess patients undergoing sacral neuromodulation implantation from January 2018 to December 2020.
Out of 9 patients with non-obstructive urinary retention, 3 patients underwent only initial surgery and were not considered suitable for definitive implantation due to lack of response to urinary recovery. The other 6 patients were permanently implanted at NMS because they were found to be suitable. Of these 6 patients: 4 women and 2 men underwent sacral neuromodulation with insertion in the S3 sacral foramen unilaterally of the quadripolar electrode. The pre-operative neuro-urological work-up included: brain and spinal cord MRI, urinary diary, complete urodynamic examination, urine examination and ultrasound of the urinary tract negative for any notable pathology. These patients retained proprioceptive sensitivity to filling and performed intermittent self-catheterization. The post-operative follow up includes weekly checks for the first 30 days and then quarterly with compilation of the urinary diary uroflowmetry and evaluation of postminctional residual.
All 6 patients performed clean bladder self-catheterization 4 - 6 times a day before implantation of the neuromodulator. After the definitive implantation, they were instructed and provided with a remote control allowing them to self-stimulate by switching the pulse generator on and off, offering them self-management in the sacral stimulation mode. The originality of this work is precisely the self-management and the stimulation mode, which does not involve continuous stimulation 24 hours a day, but stimulation that the patient starts 15-20 minutes before each urination and stops after urination.

Our 6 patients aged between 23 and 71 years (4 women and 2 men) are followed for a minimum of 14 to a maximum of 48 months. 5 patients have given up bladder self-catheterization and show satisfactory urinary recovery with no significant post-micturition residual, only one patient shows a post-micturition residual not exceeding 150 ml, despite having resumed urination and occasionally performs self-catheterization.

We have noticed in our experience that patients undergoing neurostimulation for the resolution of urinary retention benefit from chronic stimulation but equally they can benefit from self-managed stimulation which certainly offers less discomfort to the patient and a saving of battery energy which we think can have a significantly prolonged validity over time.

Sacral nerve stimulation is effective in restoring voiding in patients with retention refractory to other forms of treatment. Offering the possibility to stimulate the innervation only at the time needed to urinate seems to us a good alternative to continuous stimulation throughout life.
Sacral neuromodulation in the on-demand mode can certainly be more accepted by the patient, reduces neuroplasticity which negatively affects the validity of the treatment over time and prolongs the exhaustion time of the pulse generator.