Differences in fatigability of muscles involved in fecal continence: Potential clinical ramifications. Physiol Rep 2021 Dec;9(24):e15144
Date
12/21/2021Pubmed ID
34927399Pubmed Central ID
PMC8685596DOI
10.14814/phy2.15144Scopus ID
2-s2.0-85121744043 (requires institutional sign-in at Scopus site)Abstract
INTRODUCTION: Fatigue of the anal sphincter complex has been demonstrated using high-resolution anorectal manometry (HRAM). However, the fatigability of individual muscles such as the external anal sphincter (EAS) and puborectalis muscles (PRM) has not been described. Vaginal manometry has been used to study contractile activity of the PRM. By applying both modalities, we attempted to differentiate the fatigability between the PRM and the EAS under different exercise conditions.
METHODS: We studied two groups: group 1, 12 healthy women (21 ± 2.7 years) with HRAM and group 2, 10 healthy (20 ± 3 years) women with vaginal manometry. All subjects performed 40 repetitive contractions with and without an intra-anal resistive load. In group 1, areas under the curve (AUC) of the anal canal high-pressure zone (HPZ) including the caudal and rostral halves were compared. In group 2, the maximum and mean pressures of the vaginal HPZ were compared.
RESULTS: The AUC decreased significantly only after repetitive contractions against a resistive load (462 ± 129 vs. 390 ± 131 mmHg-cm, p = 0.02), indicating fatigue. The caudal half (EAS) decreased significantly after contractions against a load (288 ± 75 vs. 239 ± 82 mmHg-cm, p = 0.02), while the rostral half (PRM) did not. The vaginal pressures (PRM) also decreased only after repetitive contractions against a load (maximum pressures, 358 ± 171 vs. 239 ± 109 mmHg, p = 0.02).
CONCLUSIONS: The EAS and PRM both exhibit fatigue with contractions only against a resistive load. These findings may guide the development of appropriate exercise regimens to target specific muscles involved in fecal continence.
Author List
Patel K, Mei L, Yu E, Kern M, Lehal N, Edeani F, Sanvanson P, Davidson ERW, Shaker RAuthors
Emily Davidson MD Assistant Professor in the Obstetrics and Gynecology department at Medical College of WisconsinFrancis Edeani MD Assistant Professor in the Medicine department at Medical College of Wisconsin
Ling Mei MD Associate Professor in the Medicine department at Medical College of Wisconsin
Patrick P. Sanvanson MD Associate Professor in the Medicine department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
AdolescentAnal Canal
Defecation
Fecal Incontinence
Female
Humans
Manometry
Muscle Contraction
Muscle Fatigue
Muscle, Skeletal
Pelvic Floor
Prospective Studies
Random Allocation
Young Adult
