Obstetrics & Gynaecology Forum Volume 29 | Issue 3 | 2019

O&G Forum 2019; 29: 7 - 10 REVIEW Posterior Tibial Nerve Stimulation (PTNS) External intermittent neuromodulation such as PTNS sends electri- cal stimuli to the sacral nerve plexus via a 34-guage needle inserted at a 60 degree angle just above the medial aspect of the ankle. The current is titrated according to patient response. Patients typical- ly receive twelve, thirty minute treatments on a weekly basis and thereafter treatment cycles may need to be repeated periodically. 6,7 The modulatory effects of the PTNS on the impulses to and from the bladder have resulted in subjective symptomatic improve- ment in approximately 60% of patients, along with an objective improvement in frequency voiding chart parameters of up to 57% with, a good long term consistency. These results may be affected by some bias, as the patients receiving PTNS are also often the beneficiaries of regular visits and follow up, support groups etc, but compared to the sham treatment (placebo) improvement of 21% are still promising. 8 The clinician may consider PTNS in patients with OAB who have shown a poor response to antimuscarinics, or who are unable to tolerate the side effects of medical management. 6,7,8 Figure 1. Posterior Tibial Nerve Stimulation device (from: www.ptns.com.au ) Sacral Nerve Stimulation (SNS) While PTNS is inexpensive and minimally invasive, it can be a te- dious treatment option. Therefore novel procedures with implants have been proposed. 8 Sacral neuromodulation works on a similar basis to peripheral nerve stimulation, but acts via direct stimulation of the sacral nerve to modulate the afferent and efferent impulses to and from the bladder. SNS is currently FDA approved for OAB (including refractory urge incontinence), Non-obstructive urinary retention, and fecal incontinence. Small case studies show some benefit of SNS in patients with spinal cord disease, lower motor neuron disease, and with pudendal nerve pain and female sexual dysfunction. 9 There is scant data on the clinical and urodynamic predictors of success in SNS, however, current guidelines recom- mend SNS for patients with recalcitrant urge incontinence who have failed other conservative measures of management. 7,10,11,12 Given the fact that Botox and SNS are essentially recommended for the same clinical scenario it may be confusing for the clini- cian to decide between the treatment modalities. The Rosetta trial looked at the difference between SNS and Botox for patients with refractory OAB. Although Botox showed a small statistically sig- nificant benefit over SNS, this benefit is stated by the authors to be ‘of uncertain clinical importance’. Additionally, any possible benefit must be balanced against the increased potential for urinary tract infections and the need for self-catheterisation. 13 Figure 2. Sacral nerve stimulation device implanted above the buttocks (from: www. consultqd. clevelandclinic.org) 1.3. Other Cystoplasty and urinary diversion: Destructive procedures such as clam cystoplasty or urinary diver- sion are salvage measures for patients with severe refractory OAB, generally secondary to neurogenic detrusor overactivity, or for structurally contracted bladders which are poorly compliant and may be seen after infections such as TB, and fibrosis. 14 2. Stress Urinary Incontinence (SUI): SUI is defined as the ‘involuntary loss of urine’ on effort or physical exertion, or from sneezing or coughing. 11 Surgical treatment re- mains the mainstay of treatment for SUI in patients who have failed conservative management including lifestyle modification, phys- iotherapy, behavioural therapy and scheduled voiding. 15 Although a multitude of procedures for the treatment of SUI have been proposed, currently no ideal procedure in terms of cost, simplicity and ease of use, efficacy and morbidity has been found. 15 2.1. Anterior repair The 2017 Cochrane Review of 10 trials compared anterior vaginal repair and other interventions in women with urinary incontinence (SUI or mixed urinary incontinence). Such interventions included physiotherapy, bladder neck needle suspension, and open retro- pubic suspension. There were no trials comparing anterior repair with mid-urethral slings or laparoscopic colposuspension, which is unfortunate. The review found that anterior repair was less effective than open retropubic colposuspension procedures – the tradition- ally quoted ‘gold standard’ procedure for SUI, even in women with concurrent pelvic organ prolapse. However, the review culminated in an open-ended conclusion, stating that the lack of information on the comparative post-operative complications and morbidity associated with the two procedures did not allow for a final verdict on anterior repair for SUI. 16 2.2. Retropubic Colposuspension (retropubic urethropexy) The open colposuspension has been traditionally quoted as the gold standard for SUI. Of the various retropubic colposuspension pro- cedures described historically, the Burch colposuspension and the Marshall-Marchetti-Krantz (MMK) have traditionally shown longer term success in the treatment of stress urinary incontinence. Of the two procedures, only the Burch Colposuspension is recommended by the 6 th ICI in 2017. 10 The 2017 Cochrane review showed conti- nence rates of up to 90% within a year of treatment with the open Burch colposuspension. This response decreases to approximately 70% overall continence after 5 years. 17 The colposuspension can be performed via open or endoscopic routes. For obvious reasons, laparoscopic colposuspension allows for improved recovery times, and looks like a promising alternative to open surgery, but the long OBSTETRICS & GYNAECOLOGY FORUM 2019 | ISSUE 3 | 8