DO WOMEN WITH PROLAPSE HAVE LEVATOR ANI IMPAIRMENT?

骨盆器官脱垂（POP）发生的基本机制尚不明确。长期以来，人们一直假设提肛肌损伤与POP有关，但这一假设尚未得到证实。本病例对照研究将检验零假设，即盆腔器官脱垂的女性（病例）和支撑正常的女性（对照组）的提肛肌结构和功能相同。我们将研究150例盆腔器官脱垂超过1厘米的女性，以及150例无症状的对照组，他们的支持与年龄、胎次和种族相匹配。先前接受过POP治疗的妇女将被排除在外。将探讨案例和对照之间LA结构和功能的差异。LA结构和功能测试：LA肌肉解剖结构异常将在高分辨率质子密度MR图像中量化。LA强度将在休息和最大肌肉收缩时测量。目的一：检验零假设，即在病例和对照组的MR图像中，LA的耻骨内脏部分的解剖横截面积没有差异。目的2：检验零假设，即与对照组相比，在休息或最大收缩功能期间，病例中的LA肌力没有差异。根据脱垂的大小和类型以及是否存在应力性尿失禁，还将进行提上睑肌解剖和力量的亚分析。分析可能导致脱垂的协变量，包括既往子宫切除术、肥胖、雌激素水平、举重和脱垂家族史。目的3：检验零假设，即无论在病例还是对照中，肌肉横截面积都与LA强度无关。这项研究的重要性在于它提供了关于POP妇女存在的特定功能和解剖缺陷的基本见解，这将导致改进对这种常见疾病的研究。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.