anal sphincter


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anal sphincter

[′ān·əl ′sfiŋk·tər]
(anatomy)
Either of two muscles, one voluntary and the other involuntary, controlling closing of the anus in vertebrates.
References in periodicals archive ?
Some studies, however, have reported that the probability of new anal sphincter injury following vaginal delivery is 3% (18).
In the following 3 hours, the patient developed symptoms of paraplegia and paresthesia below the T4 dermatome in the ED and lost his anal sphincter function.
Absence of any anal fissure/fistula or associated inflammatory signal changes around anal sphincter muscles suggests HMAS in patients with relevant clinical signs and symptoms (Fig.
Mediolateral episiotomy reduces the risk for anal sphincter injury during operative vaginal delivery.
In the distal anal canal, the IAS is thin; therefore, we measured the PBT, anterior anal sphincter defect and anal sphincter defect angle at the level of the mid-anal canal, which can be clearly delineated by the presence of the most prominent hypoechoic ring of the IAS.
Clinically detectable anal sphincter injuries occur in about 0.4-19% of vaginal deliveries.
Modified Ritgen's maneuver for anal sphincter injury at delivery: a randomised controlled trial.
A combine surgical and medical approach with the use of botulinum toxin injection into anal sphincter also causes reversible sphincterotomy and was first investigated in 1993.15-16
* Exposure of horizontal fibres of the internal anal sphincter (IAS).