title: Levator ani muscle avulsion is a risk factor for expulsion within 1 year of vaginal pessary placed for pelvic organ prolapse.
abstract: OBJECTIVE
  The aim of this study was to investigate whether the presence of levator ani muscle (LAM) avulsion is associated with expulsion within 1 year of a vaginal pessary placed for pelvic organ prolapse (POP).
  
  
  METHODS
  This was a prospective observational study of consecutive women with symptomatic POP, who had not received treatment for the condition before the consultation and opted for vaginal pessary placement in our center. Volume acquisition was performed before pessary insertion and offline analysis of the 3D/4D transperineal ultrasound volume data was performed. LAM was assessed on maximum pelvic floor muscle contraction (PFMC) and hiatal dimensions were assessed at rest, on PFMC and on maximum Valsalva. Results were compared between women in whom the pessary was retained for 1 year and those in whom the pessary was expelled within 1 year.
  
  
  RESULTS
  The datasets of 255 women were analyzed including 147 (57.6%) women who had a vaginal pessary continuously in place over 1 year and 108 (42.4%) with pessary expulsion. Mean age was 63.2 (SD, 9.9) years and median parity was 3 (2-4). Eighteen (7.1%) had Stage I, 164 (64.3%) Stage II, 67 (26.3%) Stage III and six (2.4%) Stage IV POP. Women with vaginal pessary expulsion within 1 year had significantly larger hiatal dimensions at rest and on Valsalva, larger hiatal area during rest, PFMC and Valsalva and higher rate of LAM avulsion (53.7% vs 27.2%, P < 0.01) compared with women in whom the pessary was retained for 1 year. After controlling for potential confounders, LAM avulsion remained a risk factor (OR, 3.18, P < 0.01) of vaginal pessary expulsion within 1 year.
  
  
  CONCLUSIONS
  Women in whom a vaginal pessary was expelled within 1 year of placement for POP had a larger hiatus. Presence of LAM avulsion was associated with a three-fold increase in the risk of expulsion of a vaginal pessary within 1 year. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.
authors.affiliation: Department of Obstetrics & Gynaecology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China.
authors.forename: R Y K
authors.initials: RYK
authors.lastname: Cheung
authors.affiliation: Department of Obstetrics & Gynaecology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China.
authors.forename: J H S
authors.initials: JHS
authors.lastname: Lee
authors.affiliation: Department of Obstetrics & Gynaecology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China.
authors.forename: L L
authors.initials: LL
authors.lastname: Lee
authors.affiliation: Department of Obstetrics & Gynaecology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China.
authors.forename: T K H
authors.initials: TKH
authors.lastname: Chung
authors.affiliation: Department of Obstetrics & Gynaecology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China.
authors.forename: S S C
authors.initials: SSC
authors.lastname: Chan
mesh_terms: D001003:Anal Canal / Q000000981:diagnostic imaging / Q000293:injuries* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology; D010298:Parity; D017773:Pelvic Floor / Q000000981:diagnostic imaging* / Q000503:physiopathology; D056887:Pelvic Organ Prolapse / Q000000981:diagnostic imaging* / Q000503:physiopathology; D010570:Pessaries / Q000009:adverse effects; D011446:Prospective Studies; D015203:Reproducibility of Results; D012307:Risk Factors; D014463:Ultrasonography; D014621:Vagina
keywords: hiatal dimensions; levator ani muscle; pelvic organ prolapse; pubovisceral muscle; transperineal ultrasound; vaginal pessary