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.
Abdool
Zeelha
Z
Department of Obstetrics and Gynecology, Pretoria Academic Hospital, Pretoria, South Africa.
Shek
Ka Lai
KL
Dietz
Hans Peter
HP
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