Paraplegia Induced by Spinal Cord Trauma
The control of bladder emptying and continence is exerted by the brain, the spinal cord and the peripheral nerves located outside the central nervous system.
Bladder dysfunction may manifest itself differently depending on the extent of the medullary lesion. Paraplegic patients usually present poor coordination ofthe bladder, as well as of the vesical wall muscles and the sphincter. The ensuing uncontrolled vesical contractions prevent any sphincter relaxation. Up to the 1970s, this dysfunction caused late kidney complications leading to premature death in 80% of all cases. Kidney failure can result from simultaneous perturbation of the interaction between the sphincters associated with high intravesical pressure leading to a reflux of urine into the ureters and the kidneys. It is one of the main causes of death following medullary trauma. Because no cure for spinal cord trauma is likely to be found in the foreseeable future, the therapeutic priority in paraplegic patients is to protect the kidneys. Electrical devices and medication are both needed to restore the control of the urogenital apparatus and the gastrointestinal system. Autocatheterism is an effective and simple method for a paraplegic patient to empty the bladder.
Because of vesical spasm, pharmacological treatment is also required to maintain relatively low intravesical pressure. This treatment may be substituted or complemented with a device which informs the patient about his or her current vesical volume and thus indicates the right moment to empty the bladder with a catheter. Bladder relaxation can be achieved by administering anticholinergic medication, but such medication often causes adverse side effects. An alternative approach consists in the direct injection into the bladder of botulin toxin, a nerve poison. The toxin causes a reduction in vesical hyperactivity but does not allow electrically triggered miction.
The sacral nerve roots are visualized on both sides by laparoscopy and are then implanted with electrodes. The method corresponds to the LION procedure developed by Prof. Possover. Electrode implantation is important for a number of reasons:
- as a means to restore erection, which is triggered by an electrical stimulus, and targeted contraction of gluteal muscles;
- as a means to restore bladder emptying and defecation;
- as a means to electrically trigger ejaculation.
The electrodes in this procedure are connected to an implant which is flatter than the stimulator in the LION procedure where sacral neuromodulation is used to control nerve pain and vesical dysfunction. The device is remotely controlled.
Benefits and Risks
Laparoscopic implantation of electrodes on sacral roots, as developed by Prof. Possover, offers significant advantages in comparison with classical treatment.
It is a minimally invasive surgical technique that does not involve any resection of vertebral fragments and requires only brief hospitalization (3 to 4 days). In addition, because the electrodes reside deep inside the pelvic cavity, the risk of wounding, shifting or infection is significantly lower.
The following objectives can be achieved thanks to laparoscopic implantation of electrodes:
- Electrically controlled blocking of the nerves connected to the central nervous system, leading to a decrease in intravesical pressure and an increase in bladder capacity. The sectioning of posterior nerve roots is rendered obsolete by this procedure.
- An electrical trigger of miction, defecation, erection and ejaculation.
- Optimal prophylaxis of bedsores and gluteal compression ulcerations. Bilateral stimulation of the sacral nerve roots stimulates the gluteal muscles, leading to significantly improved cutaneous circulation.
- Implantation of additional electrodes
- Implantation that does not require the removal of any vertebral element
- Minimally invasive implantation. Hospitalization only lasts a few days instead of several weeks, as needed for the conventional method.