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

Abstract

ObjectivesTHD 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. Study designA 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. ResultsA 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). ConclusionAnopress seems promising in the assessment of anal sphincter function in women with OASI and can potentially make anal manometry testing easily accessible to urogynecologists.