The effect of levator avulsion on hiatal dimension and function.
OBJECTIVE
Pelvic floor trauma as a result of vaginal childbirth can cause significant pelvic floor morbidity. In this observational study, we intended to define whether such trauma is associated with abnormal hiatal biometry and/or abnormal biomechanical properties of the levator muscle.


METHODS
The datasets of 414 urogynecologic patients were assessed in a retrospective study. Patients underwent an interview, clinical examination, and 3-/4-dimensional pelvic floor ultrasound. All analysis was performed offline using proprietary software. Hiatal dimensions and strain were measured.


RESULTS
In 21.1% of parous women with a history of vaginal delivery, an avulsion of the levator muscle was diagnosed, and in 8.6% it was bilateral. The relative risk of abnormal distensibility was 3.5 (95% confidence interval, 1.7-6.5) in unilateral and 3.96 (95% confidence interval, 1.7-9.2) in bilateral avulsion. Avulsion increased muscle distensibility on Valsalva and reduced muscle shortening on pelvic floor muscle contraction.


CONCLUSIONS
Avulsion injury is associated with abnormal levator biometry and function.
Department of Obstetrics and Gynecology, Pretoria Academic Hospital, Pretoria, South Africa.
Zeelha
Z
Abdool
Ka Lai
KL
Shek
Hans Peter
HP
Dietz
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D036861:Delivery, Obstetric; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008875:Middle Aged; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging*; D007744:Obstetric Labor Complications / Q000000981:diagnostic imaging*; D017773:Pelvic Floor / Q000000981:diagnostic imaging* / Q000293:injuries; D011247:Pregnancy; D012189:Retrospective Studies; D014463:Ultrasonography / Q000379:methods; D055815:Young Adult