History of Percutaneous Posterior Tibial Nerve Stimulation and Its Relation to Acupuncture
The posterior tibial nerve is a mixed nerve, containing both motor and sensory nerve fibers. PTNS involves inserting a fine-gauge needle just above the ankle (at the site of the posterior tibial nerve). The inserted needle is attached to an electric stimulator; the tibial nerve then carries electrical signals in an afferent direction to the sacral spine. The procedure typically lasts 30 minutes and is administered weekly over a period of 12 weeks.
The “needle” used in PTNS is actually a 36-gauge acupuncture needle inserted by using a specially designed guiding tube. The guiding tube was invented by a blind Japanese acupuncturist, Waichi Sugiyama, in the 17th century; it is currently used by the majority of acupuncturists worldwide.
It is reasonable to consider the PTNS technique is a variation of the electroacupuncture technique commonly used by acupuncturists, not only because of the needling materials used in PTNS but also because its concept was derived from the practice of acupuncture. The stimulation site used in PTNS is the SP6 acupuncture point. This well-known acupuncture point has been traditionally used to treat a wide variety of urological conditions.
In 1982, McGuire et al.  stimulated acupuncture points near the posterior tibial nerve (SP6 acupuncture point) with TENS and obtained good symptomatic results among patients diagnosed with detrusor (urinary bladder muscle) instability, intestinal cystitis, and neurological conditions. In 1987, Stoller  reported “prompt relief of unstable bladder” with acupuncture stimulation on the SP6 point on monkeys. With repeated treatments on the SP6 acupuncture point, progressively longer periods of bladder stability were noted. In 1988, Chang  reported results using acupuncture, showing statistically significant changes in the urinary parameters (maximum cystometric capacity and maximum flow rate) in a group of 26 women immediately after a 30-minute treatment. Acupuncture was administered on the SP6 point, which is located near the ankle over the posterior tibial nerve. In 1999, Stoller  reported the outcomes of their study using posterior tibial nerve stimulation (electroacupuncture on the SP6 point). Patients were having pelvic-floor dysfunction with symptoms such as urinary urge, incontinence, and/or pelvic pain. Stoller described an 81% clinical success rate in 90 patients after a mean follow-up of 5.1 years. Despite these promising results from administering acupuncture on the SP6 point, the therapy was not commonly used in urological practice. However, an FDA-approved electric stimulator (PercSANS™) became available commercially in February 2000 and has been used by a growing number of urology clinics.
An increasing number of research papers have been published on PTNS treatment. Most of these papers show good results for various urinary symptoms; however, the success rates were not as high as Stoller had initially reported. It should be noted that although pioneers of PTNS obtained the idea from traditional acupuncture practice [6, 7, 10], research papers on PTNS and its promotional materials rarely mentioned the word “acupuncture” once the commercial version of the PTNS unit was introduced.
Nevertheless, urology specialists have recommended that PTNS is useful for treating refractory urinary urge incontinence and should at least be considered as a therapeutic alternative before resorting to an aggressive surgery. PTNS is contraindicated for patients wearing pacemakers or defibrillators. It is also not recommended for patients with coagulopathy (a tendency toward bleeding) or neuropathy, or for pregnant women.
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