Year: 2003
Type: conference-abstract
Abstract: The etiology of anal incontinence is unknown although it is thought to be related to several factors including the external anal sphincter (EAS) and internal anal sphincter (IAS). The puborectalis muscle (PRM) may also play a role in this mechanism. The purpose of this study was to study the contribution of all three muscles to anal continence in asymptomatic women. Ten asymptomatic nullipara women underwent simultaneous 3D ultrasound imaging and manometry recordings of the anal canal. 3D imaging was performed using a mechanical, transvaginal probe placed at the vaginal introitus. Manometry measurements were taken from a catheter with 8 side holes placed circumferentially around it, at the same level as the imaging. Pressures were measured with both a station pull through (every 0.5 cm) and a rapid pull through technique (motor-driven puller, speed 8 mm/s). The ends of the high pressure zone (HPZ) of the anal canal were defined by water filled balloons. Data was collected at rest and during a sustained squeeze. 3D imaging allowed the EAS, IAS and PRM to be identified clearly in 3 perpendicular planes and correlated with the pressure readings at specific points in the anal canal. The length of the IAS was 27.4 ± 5.1 mm, the EAS was 23.3 ± 2.0 mm, the PRM was 16.6 ± 6.7 mm and the HPZ was 45.4 ± 6.7 mm. The HPZ was demarcated by the IAS and PRM in the proximal anal canal, the EAS and IAS in the middle and the EAS in the distal canal. Manometry recordings showed that during a sustained squeeze, there was an increase in pressure not only in the EAS but also, to a lesser extent, in the region of the PRM. The PRM may play an important role in contraction of the anal canal.
DOI: 10.1002/uog.382
Institution: University of California San Diego
Language: English
Subfield: Rheumatology
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W1982574933