External Anal Sphincter Fatigability Clinical Trial
Official title:
External Anal Sphincter Fatigability, an Electromyographic and Manometric Study
External anal sphincter is a Skeletal muscle under voluntary control. As described in
previous studies, it is mainly composed of type 1 fibers. Fatigability is a concept which has
been studied and described many times in skeletal limbs muscles. Two types of fatigue are
described, peripheral of central fatigue. Fatigue can been physiologic but also pathologic
(due to an affection of the muscle, the peripheral nervous system or the central nervous
system). Many tools have been used to measure muscle fatigability (direct strength measure on
isometric contraction, electromyography, echography, oxymetry...).
Besides many fatiguing methods have been developed for every each muscle depending on its
histological structure.
Anal sphincter fatigability has already been described in few manometric studies with
particularly 2 measures: Fatigue Rate and Fatigue Rate Index. Moreover, no fatiguing protocol
has been standardized to study it.
The primary aim of this study is to define a fatiguing protocol for external anal sphincter
in order to study it in further studies. Secondary aims are to assess Electromyography as a
tool for measuring this fatigability and finally to assess the link between anal sphincter
fatigability and symptoms reported by patients.
Patients over 18 years old, consulting for an Anorectal Manometry with a voluntary command on
the external anal sphincter are included.
History and treatment, height, weight, sex, age, Fatigue impact scale, digestive symptoms
with Neurologic Bowel Disorders score and Wexner scale, urinary tract symptoms with Urinary
Symptom Profile (USP) score and electromyography (Root Mean Square (RMS) and Mean Power
Frequency (MPF)) and manometric data (contraction peak, fatigue rate, fatigue rate index)
were recorded.
The fatiguing protocol consists in 10 sustained external anal sphincter contractions with
maximal voluntary contraction of 20 seconds followed by 10 seconds of resting. A training
contraction is made before the fatiguing protocol. At the end of the protocol, patients
undergo a classical anorectal manometry.
Primary outcome is the difference on root mean square in electromyography between the first
and the last fatiguing contraction.
Secondary outcomes were mean power frequency and manometric data (i.e. Fatigue Rate index
(FRI), Fatigue Rate (FR), contraction Peak)
Influence of age, sex, symptoms, pathologies, weight on fatigability will be studied in a
second analysis
n/a