Three-dimensional endoanal ultrasound assessment of the anal sphincters during rest and squeeze
Source: Acta Obstetricia et Gynecologica Scandinavica, Volume 87, Number 6, 2008 , pp. 669-674(6)
Publisher: Informa Healthcare
Abstract:Background. Current ultrasound assessment of the anal sphincter is based on measurements during rest. However, active constriction plays a role in maintaining continence. Here we assess female anal dimensions during rest and squeeze. Methods. Thirty women were recruited for a cross-sectional endoanal ultrasound study after written consent according to an ethically approved protocol: nine 0-gravida, 10 with normal vaginal delivery, and 11 with complicated vaginal delivery (babies >4,500 g, operative vaginal delivery or perineal rupture). Endoanal three-dimensional (3D)-ultrasound volume was obtained during rest and squeeze. Length of anal canal and volume of the external and internal sphincters were determined. Results. In the 0-gravida group, the mean anal canal at rest was 3.28 cm (SD: ±0.63) compared with 2.30 (±0.77) in those who had given birth (p =0.002). Correspondingly, the volume of the external sphincter was 7.61 cm3 (±2.63) versus 4.80 (±2.02) (p =0.004), and for the internal sphincter 2.63 (±1.18) versus 2.68 (±1.30) (p =0.98). There were no differences between rest and squeeze within the 0-gravida, but after a traumatic vaginal delivery the internal sphincter was smaller during squeeze (p =0.01), and the overlap between external and internal sphincter was 0.76 cm (±0.41), insignificantly shorter (p =0.09) than in the 0-gravida group at 1.21 (±0.62). Conclusions. Women with vaginal delivery had a shorter anal canal and smaller external sphincter than 0-gravida. Active squeeze had no effect on the dimensions of the sphincter apart from a reduction of the internal sphincter in those who had undergone a complicated delivery, possibly due to a dislodging upwards during squeeze.
Document Type: Research Article
Affiliations: 1: Department of Obstetrics and Gynecology, Hammerfest Hospital, Hammerfest, Norway 2: Department of Obstetrics and Gynecology, Haukeland University Hospital, Bergen, Norway 3: Institute of Community Medicine, University of Tromsø, Tromsø, Norway 4: Department of Obstetrics and Gynecology, Haukeland University Hospital, Bergen, Norway,Department of Clinical Medicine, University of Bergen, Norway
Publication date: January 1, 2008