DO WOMEN WITH PROLAPSE HAVE LEVATOR ANI IMPAIRMENT?

盆腔器官脱垂（POP）发生的基本机制尚不明确。长期以来，人们一直假设肛提肌（LA）受损与POP相关，但这一假设尚未得到验证。本病例对照研究将检验肛提肌结构和功能在盆腔器官脱垂（病例）和正常支持（对照）的女性中相同的假设。我们将研究150例盆腔器官脱垂延伸到处女膜环下超过1 cm的女性病例和150例年龄、产次和种族匹配的无症状对照组。将排除既往接受过POP治疗的女性。将寻求病例组和对照组之间LA结构和功能的差异。左心房结构和功能的测试：左心房肌肉解剖结构的结构异常将在高分辨率质子密度MR图像中量化。将在休息时和最大肌肉收缩期间测量LA强度。 目标一：检验零假设，即在病例和对照的MR图像中观察到的LA耻骨内脏部分的解剖横截面积没有差异。 目标二：检验零假设，即与对照组相比，病例组在静息或最大收缩功能期间的LA肌力无差异。还将根据脱垂的大小和类型以及是否存在压力性尿失禁对提肌解剖结构和力量进行亚分析。将对可能导致脱垂的协变量进行分析，包括既往子宫切除术、肥胖、雌激素状态、举重和脱垂家族史。目的3：检验零假设，即肌肉横截面积与病例或对照组的左心房强度无关。这项研究的重要性在于它提供了关于POP女性中存在的特定功能和解剖缺陷的基本见解，这将导致这种常见疾病的研究得到改善。这些信息将指导未来的研究，并有助于设计更合理的治疗选择。

The basic mechanisms responsible for development of pelvic organ prolapse (POP) are not established. It has long been hypothesize that levator ani (LA) muscle impairment is associated with POP but this hypothesis has not been tested. This case control study will test the Null Hypothesis that levator ani muscle structure and function are the same in women with pelvic organ prolapse (cases) and women with normal support (controls). We will study 150 Cases who will be women with pelvic organ prolapse that extends more than 1 cm below the hymenal ring and 150 asymptomatic Controls with proven normal support matched for age, parity and race. Women with prior treatment for POP will be excluded. Differences in LA structure and function between cases and controls will be sought. Tests of LA structure and function: Structural abnormalities in LA muscle anatomy will be quantified in high-resolution proton density MR images. LA strength will be measured at rest and during maximum muscle contraction. Aim I: Test the null hypotheses that there are no differences in the anatomical cross-sectional area of the pubovisceral portion of the LA as seen in MR images of cases and controls. Aim 2: Test the null hypothesis that there is no difference in LA muscle strength at rest or during maximal contraction function in cases compared to controls. Sub analyses of levator anatomy and strength based on the size and type of the prolapse as well as the presence or absence of stress incontinence will also be carried out. Analysis of covariates possibly contributing to prolapse including prior hysterectomy, obesity, estrogen status, heavy lifting, and prolapse family history will be performed. Aim 3: Test the null hypothesis that muscle cross-sectional area is not correlated with LA strength for either cases or controls. The importance of this research lies in its providing fundamental insights about the specific functional and anatomical defects present in women with POP that will lead to improved research in this common disease. This information will guide future research as well as helping to devising more rational treatment selection.