The technology

Axonics rechargeable sacral neuromodulation (SNM) system (Axonics Modulation Technologies, Inc.) is an implantable SNM therapy for bladder or bowel control in people with urinary retention, symptoms of overactive bladder or chronic faecal incontinence. SNM (also called sacral nerve stimulation) is a treatment that uses electrical impulses to stimulate the sacral nerves, located in the pelvic floor or groin area.

The Axonics SNM system includes an implantable neurostimulator, tined lead, programmers for use by the clinician and patient, and an external trial system. A wireless charging device is also included for contactless charging of the neurostimulator.

Before permanent implantation, a temporary trial of SNM is recommended to assess the efficacy of therapy. Using the external stimulator, 2 different trial stimulation techniques can be done; a percutaneous nerve evaluation test using the non-tined, single-contact temporary lead or a first-stage, tined lead test using the permanent tined lead.

The company also offers kits containing all surgical tools needed for a percutaneous nerve evaluation test and tined lead implant at extra cost.

Innovations

Axonics is currently the only rechargeable SNM system on the market. It is designed to reduce the number of invasive battery replacement procedures that would be needed every 3 to 5 years with a non-rechargeable system. The Axonics system is also smaller than non-rechargeable SNM devices. This is claimed to help reduce the risk of implant site pain and make it more suitable for people with low BMI.

Current care pathway

NICE's guidelines on urinary incontinence in women and lower urinary tract symptoms in men recommend initial management of symptoms with conservative methods (such as behavioural techniques, physical therapies or medication). If symptoms persist, people should be referred to a multidisciplinary team for specialist urological assessment and management. At this stage, investigations may be done to confirm the presence and involvement of detrusor overactivity, before offering invasive therapy such as SNM. Alternative third-line treatment options include injecting botulinum into the bladder wall, and irreversible surgical procedures such as bladder reconstruction (augmentation cystoplasty), and urinary diversion.

NICE's guideline on faecal incontinence in adults recommends starting treatment with a combination of conservative interventions (including dietary changes, addressing bowel habits, identifying coping strategies and medication) followed by specialist conservative management (such as pelvic floor muscle training, bowel retraining, specialist dietary assessment and management, biofeedback, electrical stimulation and rectal irrigation) if symptoms persist. If faecal incontinence continues after conservative management, specialist assessments should be done to identify possible causes and assess the patient's suitability for surgery. Surgical treatments include repairing or tightening the sphincter (sphincteroplasty), or a colostomy (for severe uncontrolled faecal incontinence). Neosphincter surgery (graciloplasty or an artificial anal sphincter) may be considered, although these procedures are now very rarely done in the UK. NICE's interventional procedures guidance on sacral nerve stimulation for faecal incontinence suggests it is an option that is typically offered as a surgical treatment for most patients for whom sphincter repair is inappropriate.

Population, setting and intended user

The Axonics SNM system would be used instead of non-rechargeable SNM systems in line with existing guidelines for urinary or faecal incontinence. As with other SNM devices, patient selection is guided by a positive response to a trial of tined lead testing or percutaneous nerve evaluation.

The system would be started by secondary care multidisciplinary teams including surgeons, specialist nurses and physiotherapists, and implanted by surgeons specialising in bowel or bladder dysfunction.

After implantation, patients use the remote control to adjust the level of stimulation depending on symptom control and comfort. They will also recharge the stimulator when battery level is low (as shown by the patient remote control). The company claims that the device will need recharging for 20 to 60 minutes every 1 to 2 weeks, if standard stimulation settings are used.

Costs

Technology costs

The Axonics SNM system, including necessary consumables and accessories, costs between £9,685 and £10,510 (excluding VAT) depending on the type of temporary stimulation used. The cost of replacing the system, which the company estimates is needed every 15 or more years or more often because of battery depletion, is £6,500.

The company has provided a full breakdown of component costs (see table 1, all costs exclude VAT).

All Axonics SNM system components are sold with a 12‑month product warranty.

As well as the device costs, healthcare resource associated with implantation is £4,279 for urinary incontinence and £4,431 for faecal incontinence, based on the following Health Resource Group codes:

  • Insertion of neurostimulator for treatment of urinary incontinence (LB79Z).

  • Insertion of neurostimulator electrodes for treatment of urinary incontinence (LB08Z).

  • Insertion of neurostimulator for treatment of faecal incontinence (FZ96Z).

  • Insertion of neurostimulator electrodes for treatment of faecal incontinence (FZ97Z).

Table 1 Cost of Axonics SNM system

Description

Cost

Additional information

Trial phase (basic evaluation)*

Trial lead and surgical tools

£300

Contains 1 PNE lead and all surgical tools needed for a PNE lead implant.

External stimulator

£175

Single-use, disposable external stimulator, 1 belt included.

Permanent implant**

Neurostimulator

£6,500

Battery life of more than 15 years.

Tined lead

£1,450

Permanent lead implant kit

£200

Contains all surgical tools needed for a tined lead implant.

Patient remote control

£500

Charging system

£560

Includes 1 belt and 9 adhesive carriers.

Replacement Implant

Neurostimulator

£6,500

Battery life of more than 15 years.

* For advanced evaluation, an additional £1,475 would be needed (trial lead and surgical tools are replaced with tined lead with percutaneous extension [£1,575] and lead implant kit [£200]).

** The costs associated with a permanent implant assumes that the patient had a successful basic trial evaluation. In an advanced trial evaluation, the cost associated with permanent implant would be £1,650 less because the tined lead and permanent lead implant kit would not be required.

Abbreviation: PNE; percutaneous nerve evaluation.

Costs of standard care

A standard non-rechargeable SNM device (InterStim II, Medtronic), including necessary consumables and accessories, costs between £9,765 and £9,997 (including VAT) depending on the type of temporary stimulation used. The cost of replacing the system, which is typically needed every 3 to 5 years because of battery depletion, is £7,494.

Resource consequences

If adopted, the Axonics SNM system would be used instead of a standard non-rechargeable SNM device (InterStim II, Medtronic), without needing changes to the current pathway in which SNM therapy is currently delivered in the UK.

The initial costs of implanting the Axonics system are similar to current non-rechargeable systems and, assuming the system needs replacement less often, it could reduce costs for medium- to long-term treatment (more than 5 years).

The company claims the Clinician Programmer accessory, which consists of a touchscreen colour tablet with built‑in stimulation capabilities, provides a superior user experience for the surgeon because it is designed to decrease programming time and the need for manufacturer support.

A cost-consequences study conducted in the US and sponsored by Axonics (Noblett et al. 2017) estimated that using a rechargeable SNM device for the management of overactive bladder syndrome would save $27,121 per patient over 15 years compared with a non-rechargeable device. Assumptions about the neurostimulator lifetime for the rechargeable device were based on the currently reported lifetime of rechargeable spinal cord stimulation systems. Further economic evidence-based on clinical studies with the Axonics SNM system would be helpful.