Sacral Nerve Stimulation for Faecal Incontinence - Placebo or Clinical Effective (SNS)

University of Aarhus

Status: Completed

Conditions: Faecal Incontinence; Fecal Incontinence

Treatments: Device: Sacral nerve stimulation at different stimulation amplitudes

Study type: Interventional

Funder types: Other

Identifiers

NCT03261622

005

Details and patient eligibility

About

Sacral nerve stimulation (SNS) has over the last 20 years been recognised as an efficient treatment option for faecal incontinence (FI).

In a selected patient group we have evidence that 90% of patients will have a successful test period (≥50% reduction in incontinence episodes). If preoperative there is motor response on at least 3 out of 4 poles on the lead, at a threshold ≤1.5 mAMP.

Hypotheses In a selected patient group suffering from faecal incontinence a one-stage permanent implant will be possible. The functional results will be improved as more time can be spent finding the optimal pacemaker settings as the risk of infection is reduced compared to the stage implant. One-Stage implantation gives the opportunity to test the amount of placebo effect with SNS.

During the first 3 months postoperative patients will be randomized to either stimulation amplitude set at 90% of sensory threshold (control group) or 3 periods of stimulation at 0.05v (placebo), 50% and 90% of sensory threshold. Patients are randomized in a 1 to 2 pattern. After the initial 3 months the stimulation amplitude is increased to sensory threshold. After six months the project ends and the number of patients achieving the 50% improvement in incontinence episodes are evaluated.

Full description

Sacral nerve stimulation (SNS) has over the last 20 years been recognised as an efficient treatment option for faecal incontinence (FI). The therapy is recommended by the International Continence Society (ICS) if conservative treatments such as; regulation of diet and fibre supplements, medication, biofeedback therapy, glycerol suppositories, mini enema or transanal irrigation have been insufficient to improve continence to a satisfactory level.

The SNS therapy has traditionally been applied as a two step procedure. Firstly, a 3-4 week test-period, often with a permanent electrode with tines, followed by permanent implantation if at least a 50% symptom reduction has been obtained during the test stimulation.

In a selected patient group(idiopathic faecal incontinence or incontinence as a result of an external anal sphincter tear (<160 degrees)) we have evidence that 90% of patients will have a successful test period (≥50% reduction in incontinence episodes). If preoperative there is motor response on at least 3 out of 4 poles on the lead, at a threshold ≤1.5 mAMP(unpublished data, submitted for publication) .

Thus, only 10% of the patients have the lead explanted after 3 to 4 weeks. In 90% of the patients a pacemaker is implanted after the test period, these patients will have an additional operation that could have been avoided if they had the permanent pacemaker implanted at the first stage.

Hypotheses In a selected patient group suffering from faecal incontinence a one-stage permanent implant will be possible. The functional results will be improved as more time can be spent finding the optimal pacemaker settings as the risk of infection is reduced compared to the stage implant. One-Stage implantation gives the opportunity to test the amount of placebo effect with SNS.

During the first 3 months postoperative patients will be randomized to either stimulation amplitude set at 90% of sensory threshold (control group) or 3 periods of stimulation at 0.05v (placebo), 50% and 90% of sensory threshold. Patients are randomized. After the initial 3 months the stimulation amplitude is increased to sensory threshold. After six months the project ends and the number of patients achieving the 50% improvement in incontinence episodes are evaluated.

Enrollment: 73 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• ≥18 years
• Informed consent
• Idiopathic faecal incontinence or incontinence following external sphincter tear ≤ 160 degrees.
• ≥ one faecal incontinence episode after optimized conservative treatment.
• Ability to use the patient programmer.

Exclusion criteria

• Pregnancy
• Diabetes
• Neurological diseases, including spinal cord injuries
• Pelvic irradiation
• Rectal resections

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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73 participants in 2 patient groups

Control arm

Active Comparator group

Description:

Stimulation amplitude at 90% of sensory threshold during period 1 to 3. (each period 4 weeks)

Treatment:

Device: Sacral nerve stimulation at different stimulation amplitudes

Intervention arm

Sham Comparator group

Description:

Alternation of stimulation amplitude 1. Period - Stimulation amplitude 0.05 Volts (lowest possible) 2. Period - Stimulation amplitude - 50% of sensory threshold. 3. Period - Stimulation amplitude - 90% of sensory threshold.

Treatment:

Device: Sacral nerve stimulation at different stimulation amplitudes