Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Aug 10;22(1):339.
doi: 10.1186/s12905-022-01915-7.

Obstetric anal sphincter injuries (OASIS): using transperineal ultrasound (TPUS) for detecting, visualizing and monitoring the healing process

Anna-Lena Stickelmann  1 , Lieven Nils Kennes  2 , Miriam Hölscher  3 , Charlotte Graef  3 , Tomas Kupec  3 , Julia Wittenborn  3 , Elmar Stickeler  3 , Laila Najjari  3
Affiliations

Obstetric anal sphincter injuries (OASIS): using transperineal ultrasound (TPUS) for detecting, visualizing and monitoring the healing process

Anna-Lena Stickelmann et al. BMC Womens Health. .

Abstract

Purpose: The aim of this study was to examine whether OASIS, and its extent, can be confirmed or excluded using transperineal ultrasound (TPUS). A further objective of this study was to monitor the healing process over a period of 6 months and to establish a connection between the sonographic appearance of obstetric anal sphincter injury (OASIS) and anal incontinence.

Materials and methods: In this retrospective clinical study, women with OASIS who gave birth between March 2014 and August 2019 were enrolled. All the patients underwent TPUS 3 days and 6 months after delivery. A GE E8 Voluson ultrasound system with a 3.5-5 MHz ultrasound probe was used. The ultrasound images showed a third-degree injury, with the measurement of the width of the tear and its extent (superficial, partial, complete, EAS and IAS involvement). A positive contraction effect, a sign of sufficient contraction, was documented. Six months after delivery, a sonographic assessment of the healing (healed, scar or still fully present) was performed. A Wexner score was obtained from each patient. The patients' medical histories, including age, parity, episiotomy and child's weight, were added.

Results: Thirty-one of the 55 recruited patients were included in the statistical evaluation. Three patients were excluded from the statistical evaluation because OASIS was excluded on TPUS 3 days after delivery. One patient underwent revision surgery for anal incontinence and an inadequately repaired anal sphincter injury, as shown sonographic assessment, 9 days after delivery. Twenty patients were excluded for other reasons. The results suggest that a tear that appears smaller (in mm) after 3 days implies better healing after 6 months. This effect was statistically significant, with a significance level of alpha = 5% (p = 0.0328). Regarding anal incontinence, women who received an episiotomy had fewer anal incontinence symptoms after 6 months. The effect of episiotomy was statistically significant, with a significance level of alpha = 5% (p = 0.0367).

Conclusion: TPUS is an accessible, non-invasive method for detecting, quantifying, following-up and monitoring OASIS in patients with third-degree perineal tears. The width, as obtained by sonography, is important with regard to the healing of OASIS. A mediolateral episiotomy seems to prevent anal incontinence after 6 months.

Keywords: Anal sphincter injuries; Obstetric anal sphincter injury; Third-degree perineal tear; Transperineal ultrasound.

PubMed Disclaimer

Conflict of interest statement

The authors declare that they have no competing interests.

Figures

Fig. 1
Fig. 1
Transperineal ultrasound of the anal sphincter. a Intact anal sphincter EAS IAS lumen b positive contraction effect—the sphincter disappears c complete tear of the EAS 3 days after delivery d scar of the EAS after 6 months
Fig. 2
Fig. 2
Model of a third-degree OASIS. a superficial tear of the EAS b partial tear of the EAS c complete tear of the EAS d EAS and IAS affected
Fig. 3
Fig. 3
Cohort
Fig. 4
Fig. 4
Probability of healing. x: tear in mm after 3 days; y: probability of healing after 6 months
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. Deutsche Gesellschaft für Gynäkologie und Geburtshilfe. Leitlinie zum Management von Dammrissen III. und IV. Grades nach vaginaler Geburt. https://www.awmf.org/uploads/tx_szleitlinien/015-079l_S2k_Dammriss-III-I....
    1. Schumpelick V, Rath W, Willis S, Faridi A. Anale Inkontinenz nach vaginaler Geburt: Ein Argument für den Kaiserschnitt auf Wunsch ? Deutsches Ärzteblatt. 2002;99:1–2.
    1. Harvey M-A, Pierce M, Walter J-E, Chou Q, Diamond P, Epp A, et al. Obstetrical anal sphincter injuries (OASIS): prevention, recognition, and repair. J Obstet Gynaecol Can. 2015;37:1131–1148. doi: 10.1016/s1701-2163(16)30081-0. - DOI - PubMed
    1. Okeahialam NA, Wong KW, Thakar R, Sultan AH. The incidence of wound complications following primary repair of obstetric anal sphincter injuries (OASIs): a systematic review and meta-analysis. Am J Obstet Gynecol. 2022 doi: 10.1016/j.ajog.2022.05.012. - DOI - PubMed
    1. Okeahialam NA, Thakar R, Sultan AH. Early secondary repair of obstetric anal sphincter injuries (OASIs): experience and a review of the literature. Int Urogynecol J. 2021;32:1611–1622. doi: 10.1007/s00192-021-04822-x. - DOI - PubMed

MeSH terms