High-resolution and 3D anorectal manometric parameters based on the London Protocol as a useful tool in the evaluation and follow-up of incontinent women patients undergoing biofeedback therapy

Background/Aim Fecal incontinence (FI) has a multifactorial pathophysiology with a potentially devastating impact on quality of life. The landmark development of high-resolution manometry (HRM) has allowed accurate assessment of anorectal function. Biofeedback (BF) has been recommended as a minimally invasive non-surgical therapeutic tool. This study aims to evaluate high-resolution and 3D manometric parameters based on the London Protocol (LP) for the diagnosis of incontinence compared to healthy volunteers, as well as the manometric repercussions of incontinent patients undergoing the BF protocol and its effectiveness. Methods Twenty-four female incontinent patients underwent water-perfused 36-channel HRM were compared to 25 healthy female volunteers. Incontinent were submitted to an 8-week BF protocol and their manometric parameters and fecal incontinence scores were compared to pre-BF, 3 and 6 months (m) after BF completion. All manometric data (post-BF, 3 and 6m period) were compared with healthy individuals. Results Incontinent pre-BF vs healthy: resting- lower pressure (mean maximum, mean,3D), shorter functional anal canal length (FACL), higher asymmetry to highest and lowest pressure; short squeeze- lower pressure (maximum incremental,absolute,mean,3D), higher asymmetry to highest and lowest pressure; endurance- lower 3D pressure (1/3, 2/3, 3/3), lower values (fatigue rate index); cough- lower pressure (anal canal, 3D, anorectal gradient), higher asymmetry to highest pressure (anal canal) and rectal sensory- higher volume (first sensation, desire to defecate, maximum tolerated). After BF (post vs pre): resting-higher pressure (3D,mean), longer FACL; short squeeze-higher pressure (maximum incremental, absolute, mean,3D), long squeeze- higher 3D pressure (1/3, 2/3,3/3); cough- higher anal canal pressure (maximum,3D) and rectum pressure; rectal sensory- higher maximum tolerated volume; (3 and 6m post-BF vs pre): resting- longer FAC (3m>pre); short squeeze- higher pressure (maximum incremental, absolute, mean) and 3D (3m>pre; 6m>pre); long squeeze- higher 3D (1/3, 2/3, 3/3): (3m>pre; 6m>pre); cough - higher anal canal pressure (maximum,3D) and rectum pressure (3m>pre; 6m>pre) and rectal sensory- higher maximum tolerated volume (3m>pre; 6m>pre). Fecal incontinence scores: lower values (post, 3 and 6m < pre-BF). Conclusions High-resolution and 3D parameters can refine FI diagnosis and provide a robust basis for personalized biofeedback therapy and follow up in selected cases, leading to enhanced outcomes.