Measurement of anal cushions in continent women

Abstract

Aim: Anal cushions are connective tissue complexes thought to be involved in anal continence. This study aimed to assess them in continent subjects.

Method: Continent women undergoing a transvaginal ultrasound scan for gynaecological reasons were included. The anal cushions were visualized at the mid-canal level. The cross-sectional area within the internal anal sphincter (Area 1) and the area enclosed within the anal cushions (Area 2) were measured and a Cushion:Canal (C:C) ratio was derived for each patient. The measurements were repeated in the semi-erect position.

Results: One hundred and two patients with a median age of 41 (IQR 32-49) years were included. The median C:C ratio was 0.68 (IQR 0.61-0.73). Inter-observer error was 0.98 and intra-observer error was 0.99. There was no significant correlation between age and C:C ratio. The C:C ratio was significantly higher in parous than in nulliparous women (P = 0.04). A history of obstetric trauma or minimal haemorrhoidal symptoms did not influence C:C ratio. There was a significant increase in C:C ratio in the erect position. (P = 0.04).

Conclusion: There was a wide range of variability in the measurement of anal cushions in normal continent women. These were not influenced by age.