Interventional procedure consultation document

Percutaneous posterior tibial nerve stimulation for overactive bladder syndrome

The symptoms of overactive bladder syndrome include the need to urinate often and without much warning (frequency), and urge incontinence, the strong need to urinate followed by an inability to stop passing urine. It is caused by the bladder muscle contracting before the bladder is full. Percutaneous posterior tibial nerve stimulation (PTNS) for overactive bladder involves inserting a fine needle into a nerve just above the ankle. A mild electric current is passed through the needle and carried to the nerves that control bladder function.

The National Institute for Health and Clinical Excellence (NICE) is examining percutaneous posterior tibial nerve stimulation for overactive bladder syndrome and will publish guidance on its safety and efficacy to the NHS in England, Wales, Scotland and Northern Ireland. NICE’s Interventional Procedures Advisory Committee has considered the available evidence and the views of Specialist Advisers, who are consultants with knowledge of the procedure. The Advisory Committee has made provisional recommendations about percutaneous posterior tibial nerve stimulation for overactive bladder syndrome.

This document summarises the procedure and sets out the provisional recommendations made by the Advisory Committee. It has been prepared for public consultation. The Advisory Committee particularly welcomes:

• comments on the provisional recommendations
• the identification of factual inaccuracies
• additional relevant evidence, with bibliographic references where possible.

Note that this document is not NICE’s formal guidance on this procedure. The recommendations are provisional and may change after consultation.

The process that NICE will follow after the consultation period ends is as follows.

• The Advisory Committee will meet again to consider the original evidence and its provisional recommendations in the light of the comments received during consultation.
• The Advisory Committee will then prepare draft guidance which will be the basis for NICE’s guidance on the use of the procedure in the NHS in England, Wales, Scotland and Northern Ireland.

For further details, see the Interventional Procedures Programme manual, which is available from the NICE website (www.nice.org.uk/ipprogrammemanual).

NICE is committed to promoting through its guidance race and disability equality and equality between men and women, and to eliminating all forms of discrimination. One of the ways we do this is by trying to involve as wide a range of people and interest groups as possible in the development of our guidance on interventional procedures. In particular, we aim to encourage people and organisations from groups in the population who might not normally comment on our guidance to do so. We also ask consultees to highlight any ways in which draft guidance fails to promote equality or tackle discrimination and give suggestions for how it might be improved. NICE reserves the right to summarise and edit comments received during consultations, or not to publish them at all, where in the reasonable opinion of NICE, the comments are voluminous, publication would be unlawful or publication would otherwise be inappropriate.

Closing date for comments: 23 June 2010

Target date for publication of guidance: September 2010

1   Provisional recommendations

1.1   Current evidence on percutaneous posterior tibial nerve stimulation (PTNS) for overactive bladder (OAB) syndrome shows that it is efficacious in reducing symptoms in the short and medium term. There are no major safety concerns. Therefore, the procedure may be used provided that normal arrangements are in place for clinical governance, consent and audit.

2   The procedure

2.1   Indications and current treatments

2.1.1   OAB syndrome is defined as urgency, with or without urge urinary incontinence, usually with frequency and nocturia. In most cases, the cause of the overactive bladder is unknown. In some cases, it is associated with neurological conditions such as multiple sclerosis or Parkinson’s disease.  

2.2   First-line treatments for OAB include bladder training, pelvic floor muscle training and anticholinergic drugs. In patients for whom conservative treatments have been unsuccessful, sacral nerve stimulation is sometimes used. More extensive surgical options for treating OAB include bladder reconstruction (such as augmentation cystoplasty) and urinary diversion.

2.2   Outline of the procedure

2.2.1   PTNS is used after conservative measures have failed. The exact mechanism of action of PTNS on the bladder is unclear, but it is thought to be mediated by retrograde stimulation of the sacral nerve plexus (neuromodulation). The posterior tibial nerve contains mixed sensory motor nerve fibres that originate from the same spinal segments as the nerves to the bladder and pelvic floor.

2.2.2   A fine-gauge needle is inserted percutaneously just above the ankle, next to the tibial nerve, and a surface electrode is placed on the foot. The needle and electrode are connected to a low voltage stimulator. Stimulation of the posterior tibial nerve produces a typical motor (plantar flexion or fanning of the toes) and sensory (tingling in the ankle, foot or toes) response. Initial treatment usually consists of 12 outpatient sessions lasting 30 minutes each, typically a week apart. Further sessions are generally needed for longer-term relief.

Sections 2.3 and 2.4 describe efficacy and safety outcomes from the published literature that the Committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the overview, available at www.nice.org.uk/guidance/IP822/overview

2.3    Efficacy

2.3.1   A randomised controlled trial (RCT) of 220 patients treated by PTNS or sham reported a moderate or marked improvement in overall bladder symptoms in 55% (60/110) and 21% (23/110) of patients respectively at 13-week follow-up (p < 0.001).

2.3.2   An RCT of 100 patients treated by PTNS or medication reported that 80% (35/44) and 55% (23/42) of patients respectively considered themselves to be cured or improved after 12 weeks of therapy (p = 0.01).

2.3.3   A case series of 90 patients reported a subjective response of 64% (58/90) and an objective response of 57% (34/60) (defined as a reduction of 50% or more in urinary leakage episodes per 24 hours) at 12-week follow-up.

2.3.4   The RCT of 100 patients treated by PTNS or medication reported a significant improvement in quality of life scores in both groups, 12 weeks after treatment.

2.3.5   In a case series of 35 patients, the proportion of patients who were symptom-free decreased from 54% (19/35) immediately after treatment to 23% (8/35) at 1-year follow-up. In a case series of 33 patients who responded to an initial 12 sessions of PTNS and were offered additional treatment sessions at varying intervals for a further 9 months, 94% (30/32) of patients considered themselves to be cured or improved at 6 months and 96% (24/25) at 12-month follow-up.

2.3.6   The Specialist Advisers commented that long-term efficacy has not been established and listed key efficacy outcomes as reduced episodes of urgency and urge incontinence, reduced daily pad usage, and improvements in quality of life and bladder capacity.

2.4   Safety

2.4.1   In the RCT of 100 patients treated by PTNS or medication, at least 1 ‘moderate adverse event’ considered to be related to the treatment was reported in 16% (8/49) and 14% (7/49) of patients respectively at 12-week follow-up. In the PTNS group, there was 1 report each of generalised swelling, worsening of incontinence, headache, haematuria, inability to tolerate stimulation, leg cramps, intermittent foot or toe pain and vasovagal response to needle placement within the 12-week follow-up period.

2.4.2   The RCT of 220 patients treated by PTNS or sham reported 7 treatment-related adverse events among the 110 patients treated by PTNS. These were bleeding or discomfort at the needle site (4% [5/110]), and 1 case each of ankle bruising and tingling in the leg.

2.4.3   The Specialist Advisers listed adverse events reported in the literature as minor bleeding, pain and infection at the needle site.

3   Further information

3.1   For related NICE guidance, see www.nice.org.uk

Bruce Campbell

Chairman, Interventional Procedures Advisory Committee

May 2010

_{Personal data will not be posted on the NICE website. In accordance with the Data Protection Act names will be anonymised, other than in circumstances where explicit permission has been given.}

_{It is the responsibility of consultees to accurately cite academic work in order that they can be validated.}