title: In vivo assessment of anterior compartment compliance and its relation to prolapse.
abstract: OBJECTIVE
  The objective of the study was to compare anterior compartment compliance between women with and without pelvic organ prolapse and to explore factors determining the extent of anterior compartment prolapse.
  
  
  METHODS
  Ten women with normal pelvic support and nine with anterior compartment prolapse were analyzed. Abdominal pressure was measured during Valsalva and simultaneous midsagittal dynamic MR imaging. The distance between the most dependent anterior vaginal wall point and a previously determined average nulliparous anterior vaginal wall point was measured. A best-fit line was determined when anterior vaginal wall displacement was plotted relative to abdominal pressure. The slope of this line is a measure of anterior compartment compliance. Multivariate analyses and t tests were performed.
  
  
  RESULTS
  Mean compliance (centimeters per centimeter of water) was higher for cases [0.05 +/- 0.006 standard error of the mean (SEM)] than controls (0.03 +/- .007, p = 0.039). Degree of anterior compartment prolapse correlated best with compliance (R (2) = 0.75, p < 0.01) and also with resting anterior vaginal wall point (R (2) = 0.55, p < 0.01).
  
  
  CONCLUSIONS
  Women with anterior compartment prolapse have a 67% more compliant support system compared with those with normal support. Both compliance and resting anterior vaginal wall location are predictors of the degree of anterior compartment prolapse.
authors.affiliation: Department of Ob-Gyn, University of Michigan, Ann Arbor, Michigan, USA. yvonne.hsu@hsc.utah.edu
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Hsu
authors.forename: Luyun
authors.initials: L
authors.lastname: Chen
authors.forename: Julie
authors.initials: J
authors.lastname: Tumbarello
authors.forename: James A
authors.initials: JA
authors.lastname: Ashton-Miller
authors.forename: John O L
authors.initials: JO
authors.lastname: DeLancey
mesh_terms: D034841:Abdominal Cavity / Q000503:physiopathology*; D001696:Biomechanical Phenomena; D003187:Compliance / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D056887:Pelvic Organ Prolapse / Q000175:diagnosis / Q000503:physiopathology*; D011312:Pressure; D012146:Rest; D012189:Retrospective Studies; D014621:Vagina / Q000503:physiopathology*; D014636:Valsalva Maneuver