Evaluation of the Anopress® device in assessment of obstetric anal sphincter injuries in a specialist urogynaecology service

Godbole L., Godbole C., Bulchandani S.
European Journal of Obstetrics and Gynecology and Reproductive Biology

THD Anopress® is a new portable anal manometry device which can be used in an outpatient clinic setting. In this study, we aimed to:

  • Evaluate anal canal resting average pressure (RAVP) and maximal squeeze pressure (MSP) as measured with Anopress in women with Obstetric Anal Sphincter Injury (OASI).
  • Study the relationship between anal canal pressures measured with Anopress with patient symptoms and Endoanal Ultrasound Scan (EAUSS) findings.

A retrospective analysis was conducted of women with OASI seen in a specialist clinic at 3- and 6-months post-delivery from November 2016 to December 2019. 72 women who attended their 6-month appointment and underwent anal manometry with Anopress were included. St Mark’s Faecal incontinence score (FI) was calculated and for the purpose of analysis patients were classified into two groups – FI score less than 5 and 5 or more. EAUSS findings were classified as sphincter defect or no defect. RAVP and MSP were measured with Anopress and compared with the variables (symptoms and EAUSS findings) using the Mann-Whitney U test.

A total of 72 women were included in the study. There were 19 (27 %), 41 (57 %), 6 (8 %) and 6 (8 %) 3a, 3b, 3c and 4th degree perineal tears respectively. The median RAVP was 17 mm Hg (Inter-Quartile Range 10.75–24 mmHg) and median MSP was 47.5 mm Hg (IQR 33−68 mmHg). 38 patients (53 %) had a demonstrable sphincter defect on EAUSS. 37 patients (51.3 %) had FI score < 5 and 35 patients (48.6 %) had FI score of 5 or more. RAVP and MSP were significantly lower with EAUSS demonstrable sphincter defect (p < 0.001). Symptom severity correlated with RAVP (p = 0.016) though its correlation with MSP was not statistically significant (p = 0.096).

Anopress seems promising in the assessment of anal sphincter function in women with OASI and can potentially make anal manometry testing easily accessible to urogynecologists.