Do resistance exercises during biofeedback therapy enhance the anal sphincter and pelvic floor muscles in anal incontinence?

Abstract

To determine if a biofeedback therapy that includes concentric resistance exercise for the anal sphincter muscles can improve muscle strength/function and improve AI symptoms compared to the traditional/non-resistance biofeedback therapy. Biofeedback therapy is the current gold standard treatment for patients with anal incontinence (AI). Lack of resistance exercise biofeedback programs is a limitation in current practice. Thirty-three women with AI (mean age 60years) were randomly assigned to concentric (resistance) or isometric (non-resistance) biofeedback training. Concentric training utilized the Functional Luminal Imaging Probe to provide progressive resistance exercises based on the patient's ability to collapse the anal canal lumen. Isometric training utilized a non-collapsible 10mm diameter probe. Both groups performed a biofeedback protocol once per week in the clinic for 12weeks and at home daily. High definition anal manometry was used to assess anal sphincter strength; symptoms were measured using FISI and UDI-6. 3D transperineal ultrasound imaging was used to assess the anal sphincter muscle integrity. Concentric and isometric groups improved FISI and UDI-6 scores to a similar degree. Both the concentric and isometric groups showed small improvement in the anal high-pressure zone; however, there was no difference between the two groups. Ultrasound image analysis revealed significant damage to the anal sphincter muscles in both patient groups. Concentric resistance biofeedback training did not improve the anal sphincter muscle function or AI symptoms beyond traditional biofeedback training. Anal sphincter muscle damage may be an important factor that limits the success of biofeedback training.