What treatment options are available for a patient with iatrogenic fecal incontinence, specifically using percutaneous nerve stimulation, such as sacral nerve stimulation (SNS)?

From the Guidelines

Percutaneous nerve stimulation, specifically sacral nerve stimulation (SNS), is a highly effective treatment option for patients with iatrogenic fecal incontinence who have failed conservative measures, with success rates ranging from 60-90% and significant improvements in quality of life. The procedure involves implanting a small device that delivers mild electrical impulses to the sacral nerves, typically S3, to help regulate bowel function 1. The treatment is typically performed in two stages: a temporary test phase lasting 2-3 weeks to assess effectiveness, followed by permanent implantation if the patient shows at least 50% improvement in symptoms.

Key Considerations for SNS

• The device consists of a lead wire connected to an implantable pulse generator placed under the skin in the upper buttock.
• Stimulation parameters are typically set at a frequency of 14-25 Hz, pulse width of 210 μs, and amplitude adjusted to patient comfort (usually 0.5-2.0 volts).
• Success rates are high, with 36% of patients reporting complete continence and 89% deemed a therapeutic success in a pivotal, uncontrolled, US multicenter trial 1.
• Alternative percutaneous approaches include posterior tibial nerve stimulation (PTNS), which involves inserting a needle electrode near the tibial nerve at the ankle for 30-minute sessions weekly for 12 weeks, then maintenance therapy.

Best Practice Advice

• A stepwise approach should be followed for management of FI, starting with conservative therapies, then pelvic floor retraining with biofeedback therapy, and considering perianal bulking agents or SNS if these measures fail 1.
• SNS should be considered for patients with moderate or severe FI who have not responded to conservative measures and biofeedback therapy, and who do not have contraindications to the procedure 1.
• Potential complications of SNS include infection, lead migration, pain at the implant site, and device malfunction, occurring in approximately 10% of patients 1.

From the Research

Treatment Options for Iatrogenic Fecal Incontinence

• Sacral nerve stimulation (SNS) is a valid treatment option for fecal incontinence, including iatrogenic cases 2, 3, 4.
• Percutaneous nerve evaluation (PNE) is a less-invasive alternative to the traditional staged approach for sacral nerve stimulation, with similar success rates and lower infection rates 5.
• SNS has been shown to improve bowel control and quality of life in patients with fecal incontinence, with a high predictive value of the diagnostic approach 3.
• The mechanism of action of SNS is not fully understood, but it appears to affect both somatic and autonomic function, leading to improved continence 2, 3.

Efficacy of Sacral Nerve Stimulation

• Studies have demonstrated a significant improvement in fecal incontinence symptoms with SNS, with a reduction in liquid or solid stool incontinence by more than 50% in a majority of patients 2, 4.
• SNS has been shown to be effective in patients with various pathophysiological conditions, including those with sphincteric lesions 4.
• The size of the sphincteric lesion does not appear to impact the outcome of SNS treatment 4.

Comparison of Treatment Approaches

• PNE has been compared to the traditional staged approach for sacral nerve stimulation, with similar success rates and lower infection rates 5.
• Biofeedback is another non-operative strategy that has been shown to be successful in treating fecal incontinence, although it may not be as effective as SNS in some cases 6.
• Other surgical options, such as anal sphincter repair and artificial bowel sphincter, may also be considered for the treatment of fecal incontinence, although they may have varying degrees of success and potential complications 6.