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abstract

162 - INTERACTIONS BETWEEN PELVIC ORGAN PROTRUSION, LEVATOR ANI DESCENT, AND HIATAL ENLARGEMENT IN WOMEN WITH AND WITHOUT PROLAPSE

162

INTERACTIONS BETWEEN PELVIC ORGANPROTRUSION, LEVATOR ANI DESCENT, AND HIATAL ENLARGEMENT IN WOMEN WITHAND WITHOUT PROLAPSE

A. G. SAMMARCO1, L.NANDIKANTI 2, E. K. KOBERNIK 1, B. XIE 1,A. JANKOWSKI 1, C. W. SWENSON 1, J. O. DELANCEY1;
1Obstetrics and Gynecology, Univ. ofMichigan, Ann Arbor, MI, 2Univ. of Michigan, Ann Arbor,MI.

Introduction: Pelvic organprolapse has two components; 1) protrusion of the pelvic organsbeyond the hymen and 2) descent of the levator ani. The POP-Q systemmeasures the first component, however, there is no standardmeasurement for the second mechanism.
Objective: Test thehypotheses that 1) difference in the protrusion area is greater thanthe area created by levator descent in prolapse patients comparedwith controls and, 2) prolapse is more strongly associated withlevator hiatus (LH) compared to urogenital hiatus (UGH).
Methods:Mid-sagittal MRI scans from 30 controls, 30 anterior predominant and30 posterior predominant prolapse patients were assessed. Levatorarea was defined as the area above the levator ani and below thesacrococcygeal inferior pubic point line. Protrusion area was definedas the protruding vaginal walls below the levator area (Figure 1).The LH and UGH lengths were measured. We used bivariate analyses andmultiple comparisons to compare demographic and clinicalcharacteristics. Bivariate logistic regression was used to assessprolapse as a function of LH, UGH, levator and protrusion areas, andPearson correlation coefficients were calculated.
Results:The levator area during Valsalva for the anterior (340±65cm2)and posterior (357±80cm2) prolapse groups weresimilar (p=.64) and larger compared to controls (209±78cm2,p<.0001 for both); similarly, protrusion areas for theanterior (143±62cm2) and posterior (144±57cm2)were similar (p=.99) and larger than controls (50±18cm2,p<.0001 for both). The LH length for the anterior (7.2±1cm)and posterior (6.9±1cm) groups were longer during Valsalva comparedto controls (5.2±1.5cm, p<.0001 for both); similarly, UGHlengths for the anterior (5.7±1cm) and posterior (6.3±1.1cm) wereboth longer than controls (3.8±.8cm, p<.0001 for both). Incomparing women with and without prolapse, the difference in levatorarea was greater than the difference in protrusion area (139.5 ±72.0cm2 v. 94.0 ± 59.0cm2, p<.0002,Figure 2). The UGH was more strongly associated with prolapse thanthe LH (UGH OR: 12.9, 95% CI: (4.1-39.2), LH OR: 4.3, 95% CI:(2.3-7.5), Table 1). LH and UGH are both correlated with levator andprotrusion areas, and all were associated with maximum prolapse size(p≤.001 for all comparisons, Table 2).
Conclusions:In prolapse, the levator area increases more than the protrusionarea. While both UGH and LH lengths increased with prolapse, UGH wasassociated with a four-fold greater odds of prolapse, which leads usto reject both the original hypotheses.
References: N/A

Table1: Odds for measure association with prolapse


OddsRatio

95%CI

P

LevatorArea*

1.3

(1.2-1.4)

<.0001

ProtrusionArea*

2.6

(1.7-4.1)

<.0001

LH**

4.2

(2.3-7.5)

<.0001

UGH**

12.6

(4.1-39.2)

<.0001

*Standardized to 1 cm increment, **Standardized to 10cm2 increment,CI: Confidence Interval, LH: Levator Hiatus, UGH: UrogenitalHiatus


Table2: Correlations Between Prolapse, Area, and Hiatus Measurements

AllSubjects (N=90)


LevatorArea

ProtrusionArea

MaxProlapse

LH

UGH

LevatorArea

1

0.71*

0.60*

0.86*

0.83*

ProtrusionArea

0.71*

1

0.73*

0.64*

0.81*

MaxProlapse

0.60*

0.73*

1

0.57*

0.70*

LH

0.86*

0.64*

0.57*

1

0.74*

UGH

0.83*

0.81*

0.70*

0.74*

1

*p≤0.001,LH: levator Hiatus, UGH: Urogenital Hiatus, Max prolapse: greatestvalue of either Ba and Bp