Endoanal ultrasound during contraction of the anal sphincter—improved definition and diagnostic accuracy

Abstract

Endoanal ultrasound was used in the investigation of 26 patients with faecal incontinence. In each case images of the anal sphincter were taken at rest and during contraction or squeezing (dynamic). Better definition of the normal anal sphincter or anal sphincter defects was obtained in 16 (62%) of the patients with imaging during contraction. In eight of the 13 patients with a sphincter defect there was better definition of the defect and increased separation of the ends of the sphincter during contraction. Imaging during contraction improves diagnostic accuracy and is a useful adjunct with endoanal ultrasound.

Translabial ultrasound assessment of the anal sphincter complex: normal measurements of the internal and external anal sphincters at the proximal, mid-, and distal levels

“…Rociu et al [37] found only moderate correlation between MRI and endoanal ultrasound. Ultrasonography also appears to be appreciated for its functional dynamic imaging capabilities [16,[39][40][41].…”

Examination techniques for endosonography of the anal canal

“…A previous study [4] has indicated that internal and external sphincter thickness are different at rest (2.1 { 0.6 mm and 6.3 { 1.0 mm, respectively) compared with sphincter thickness during pelvic floor squeeze (2.1 { 0.5 mm and 7.4 { 1.4 mm, respectively), when the sphincters are measured posteriorly at the mid canal level. It has also been reported [7] that external sphincter tears became more apparent during ''anal squeeze.'' We have not shown any evidence that ''anal squeeze'' altered the apparent size or extent of an external sphincter tear.…”

“…It was not possible to distinguish the external sphincter from the longitudinal muscle in females [5,6], but with the latest equipment, both are clearly differentiated. In addition, external sphincter changes during contraction may improve the diagnosis of tears [7].…”

L'endosonographie dans l'incontinence anale: à consommer sans modération...

“…Ces modifications anatomiques définitives peuvent gêner la visualisation du sphincter externe dans sa partie antérieure. La compression de la paroi vaginale postérieure basse par un doigt endovaginal [30] et/ou la contraction sphincté-rienne anale [32] pourrai(en)t alors faciliter l'interpré-tation des images ; -antécédents chirurgicaux complexes : certaines interventions complexes (réparations chirurgicales ité-ratives, graciloplastie, mise en place d'un sphincter artificiel) et certaines malformations congénitales entraî-nent des remaniements tissulaires majeurs qui rendent l'endosonographie souvent peu contributive [3,5].…”