Introduction
Obstetric anal sphincter injuries (OASIS) are one of the main causes of anal incontinence (AI) in young women. High-definition anorectal manometry (3D-HDARM) incorporates volumetric representation in three dimensions of the anal sphincter complex (ASC) allowing evaluate asymmetries that could represent injuries of the ASC.
Aims & Methods
Aims: Evaluate the diagnostic accuracy of 3D-HDARM in identifying postpartum ASC injuries compared to endoanal ultrasound (EAUS). Compared the anal pressures measured with 3D-HDARM in women with AI and postpartum ASC injuries and without it.
Methods: Retrospective study of all women under 50 years with AI referred to the motility lab with a history of at least one delivery without other comorbidity which justify the AI. 3D-HDARM probe equipped with 256 pressure transducers was used to measure the ASC pressures and evaluate volumetric representation of the topographic ASC to identify asymmetries. The manometric records were anonymized and interpreted by a medical expert who was unaware of the existence of the ASC injuries. Two pathological topographic patterns were considered: manometric defect (a pressure gap along the anal sphincter). and suspected scar (reveal a presive band). A 360° endoanal ultrasound probe (EUS) was used to evaluate the morphology of the ASC.
Results
27 women. 51,9% of women had an ASC injury during delivery (OASIS grade III and IV). 55,6% of the EAUS identified morphological alterations of the ASC. 55,6% of the 3D-HDARM identified topographic patterns suggestive of ASC injuries. There were no statistically significant differences in symptoms severity (Wexner and Vaizey Incontinence Score) and ASC pressures in rest and squeeze according to the presence or absence of ASC injury. The overall diagnostic accuracy of the 3D-HDARM was 77,8% (95% CI 59,2 – 89,4%), with a sensitivity of 80% (95% CI 54,8 – 93,0%), specificity of 75% (95% CI 46,8 – 91,1%), positive predictive value of 80% (95% CI 54,8 – 93,0%) and a negative predictive value of 75% (95% CI 46,8 – 91,1%).
| EAUS | ASC injury | ASC without injury | p-value |
| N (%) | 15 (55,6) | 12 (44,4) | |
| Age (years). Mean (SD) | 37,8 (5,0) | 36,8 (6,2) | 0,658 |
| BMI (kg/m2). Median (IQR) | 23,3 (21,7 – 24,0) | 21,6 (20,3 – 26,3) | 0,574 |
| Vaginal delivery. Median (IQR) | 1 (1 – 2) | 2 (1 – 2) | 0,185 |
| Instrumental delivery. N (%) | 11 (40,7) | 5 (18,5) | 0,096 |
| Episiotomy. N (%) | 6 (26,1) | 3 (13,0) | 0,648 |
| Wexner Score. Median (IQR) | 4 (4 – 10) | 5 (1,5 – 8,5) | 0,757 |
| Vaizey Score. Median (IQR) | 4 (4 – 13) | 7 (2,5 – 12,5) | 0,947 |
HD-ARM. Mean (SD)
- Anal resting pressure (mmHg)
- Anal high-pressure zone length (cm)
- Anal squeeze pressure (mmHg)
- Anal squeeze duration (s)
|
72,1 (22,8)
3,4 (0,9)
171,8 (66,2)
16,2 (9,2) |
86,3 (20,1)
3,8 (0,9)
153,8 (44,6)
9,5 (6,9) |
0,105
0,219
0,426
0,045 |
Conclusion
- 3D-HDARM may be a useful tool in the morphological assessment of the ASC in women with postpartum anal incontinence like screening tool.
- There were no differences neither in symptoms severity, nor resting and sqeezing pressures according to the presence of absence ASC injuries.
References
1. Rezaie A, Iriana S, Pimentel M, Murrell Z, Fleshner P, Zaghiyan K. Can three-dimensional high-resolution anorectal manometry detect anal sphincter defects in patients with faecal incontinence? Colorectal Dis. 2017 May;19(5):468-475. doi:10.1111/codi.13530.
2. Royal College of Obstetricians and Gynaecologists. The management of third-andfourth-degree perineal tears (Green top 29). London: Royal College of Obstetriciansand Gynaecologists. 2015.
