Clinical Application of Electronic Bladder Stimulation in Paraplegics

Abstract

In the last 2 decades great progress has been made in the care of patients with neurogenic bladders. The development of antibacterial therapy for urinary tract infections, the recommendation of intermittent catheterisation in place of continual catheter drainage, and the judicial use of operative procedures to relieve obstruction or to divert the urine, have all reduced the urologic morbidity and mortality associated with this problem. There are still some patients, however, who continue to have recurrent urinary tract infections, who do not develop a satisfactory reflex bladder, and who do not respond satisfactorily to intermittent catheterisation.The initial report of stimulation of the spinal cord and pelvic nerves occurred over 100 years ago (Budge, 1864). In the intervening years a stimulus has been given to the pudendal, hypogastric and pelvic nerves as well as the bladder, in animal laboratories. Clinical experimentation was initiated by Dees in 1940 using an intrarectal probe, and intravesical catheter-electrodes (Katona, 1958) and electrodes implanted into the detrusor muscle have also been used. The failure rate in these early studies was high and prompted our interest in a more satisfactory means of achieving complete micturition. MaterialsOur initial laboratory efforts (Friedman, Nashold and Senechal, 1972) involved acute and chronic experiments on cats and dogs. Surface stimulation of the lumbar and sacral spinal cord elicited excellent bladder pressures, but without micturition. Highest bladder pressures were obtained at the S2 level. Stimulation above Sl induced activation of skeletal muscle with contraction of the perineal musculature and tonic-clonic movement in the lower extremities.Use of a depth electrode induced similar bladder pressures with voiding. Descending visceral motor pathways for the bladder lie in the medial portion of the lateral columns and it was felt that positioning the electrodes within the central grey matter induced their activation. Subsequent autopsy examination of adult human spinal cords yielded an average depth for the intermediolateral grey column in the sacral cord of 2.5 mm. The chronic depth electrodes now used consist of 2 platinum-iridium wires 2.5 mm in length and 2.5 mm apart, mounted on a Silastic clip.The electric parameters found most helpful include a biphasic square wave at 15-20 cycles per second. The stimulus is applied for 20-30 seconds using lo-15 volts.Clinical experimentation using this stimulator was begun in 1970 and has been used in 10 patients Grimes, Nashold and Currie, 1973). The procedure was approved by the medical committee on human experimentation and the experimental nature was discussed with the patient and his family. ProceduresCareful patient selection and evaluation should be conducted before consideration of implantation of a spinal cord stimulator. In this initial patient group, only paraplegics have been con-

Control of urinary bladder function with devices: successes and failures

“…Of the male subjects, two voided successfully after bladder neck resections or partial sphincterotomies but two others failed to void even after these procedures were performed. However, two male subjects did achieve concomitant relaxation of the urethra leading to complete bladder evacuation without sphincterotomy, suggesting that at least in some patients, spinal cord stimulation can elicit coordinated voiding (Grimes et al, 1975). Ultimately, 60% of the subjects obtained clinically good micturition with low residual volumes, reductions in urinary tract infections, increases in bladder capacity and freedom from catheterization.…”

“…One advantage of ISMS is that bladder contractions can be evoked without concomitant sphincter contractions (Carter et al, 1995;Grill et al, 1999). However, more importantly, ISMS allows the possibility of activating sacral interneuronal networks that produce coordinated micturition or some part thereof (Nashold et al, 1971;Grimes et al, 1975;Grill, 2000).…”

Use of Clonidine in the Management of Patients with Neurogenic Bladder Dysfunction

“…A similar observation has been made by Nanninga et al (15) who attributed the persistence of residual urine after external urethral sphincterotomy in some of their patients to such 'detrusor deficiency'. These patients might require, apart from reduction of peak urethral pressure either by pharmacotherapy or by external sphincterotomy, drugs such as bethanechol or electrical stimulation of the spinal cord (16) or the bladder itself (17) to supplement for the 'detrusor deficiency'. off.…”

Long–Term Follow–Up of the In–Flow™ Intraurethral Insert for the Treatment of Women with Voiding Dysfunction

“…Although these treatments may prevent the complications of voiding dysfunction, it is at the expense of quality of life. Attempts to elicit detrusor contraction by electrodes implanted at the bladder wall, pelvic nerve, sacral nerve root, and spinal cord are another approach to the treatment of voiding dysfunction [4, 5, 6, 7]. These attempts produced artificial micturition patterns with high intravesical pressures and involuntary movements of the lower limbs.…”

“…These treatments may be effective in prevention of voiding dysfunction complications, however, many patients find them discouraging, imposing lower quality of life and decreased sense of self–esteem. Newer modalities of treatment include electrical stimulation to the bladder wall, pelvic nerve, sacral root and spinal cord [4, 5, 6, 7, 8]. Selective detrusor activation, and direct stereotactic selective stimulation of the sacral cord have been more recently suggested, but are still considered experimental [9, 10].…”