Stimulation a Potential Incontinence Option
by Warren Grill, senior technical editor
Urinary incontinence is a large unmet medical need with debilitating
effects. The condition affects an estimated 13 to 15 million Americans,
and almost half of the persons diagnosed with urinary incontinence
are affected by urge incontinence. Urge incontinence is the involuntary
loss of urine accompanied by the strong desire to void, and is differentiated
from stress incontinence. Present treatments including absorbent
pads, exercise, and pharmaceuticals, and are not always effective
and may cause side effects.
Currently, the only available neurotechnology device to treat urge
incontinence is the Medtronic
InterStim, which uses an electrode placed in the sacral foramen
to stimulate the sacral nerves. Other vendors, including Advanced
Neuromodulation Systems, are planning to compete with Medtronic
in this market. And Advanced
Bionics in Valencia, CA, is testing its BION injectable microstimulator
for treatment of urge incontinence.
However, recent research into tibial nerve stimulation points to
another potential neurotechnology solution for urinary incontinence.
Vera Vandoninck and colleagues reported results from a multiple-center
clinical trial in the journal Neurourology and Urodynamics. Their
trials suggest that tibial nerve stimulation may be an effective
treatment for urge incontinence. Thirty-five patients with urge
incontinence were enrolled in a prospective trial in both The Netherlands
and Italy. Patients underwent weekly stimulation sessions for 12
weeks and were evaluated at the beginning and end of treatment.
Stimulation was delivered to the posterior tibial nerve in the shank
using needle electrodes at 20 Hz for 30 minutes per session.
Sixty nine percent of the patients experienced a decrease in the
number of incontinent episodes by at least half, and 46 percent
of the patients experienced no leakage episodes after treatment.
The number of leakage episodes decreased from a median of 5 before
treatment to a median of 1 after treatment and the severity of leakage
also decreased. Further, mean capacity increased from a median of
119 ml before treatment to a median of 191 ml after treatment. Sixty
three percent of the subjects reported success and chose to continue
the treatment through a weaning period where the interval between
stimulation sessions was increased.
These data suggest that transient electrical stimulation of the
tibial nerve can exert long-lasting and powerful reductions in urge
incontinence. There were no reported side effects other than pain
at the site of stimulation. The mechanisms of this effect are not
clear, and the presence of a placebo effect was not controlled in
This approach is not entirely novel, and was the basis for the Percutaneous
Stoller Afferent Nerve Stimulation System (PerQ SANS). This technology
was invented at the University of Iowa Department of Urology. In
1993, the universitys Technology Innovation Center incubator
spun off a commercial firm called Urosurge, Inc., in Coralville,
IA to market the product. Urosurge received FDA approval for the
device for treatment of urinary incontinence in 2000. However, the
company subsequently ceased operations.