妊娠期和产后盆腔器官脱垂时肛提肌形态学及阴道粘膜神经表达特征

Neuromuscular characteristics in women with pelvic organ prolase during pregnancy and postpartum

目的比较妊娠期和产后盆腔器官脱垂(POP)时肛提肌形态学和阴道粘膜神经分布的变化,探讨妊娠和阴道分娩后POP时盆底神经肌肉病理学特征。方法常规产前检查的正常初产妇100名,在妊娠37周以后和产后42d进行盆腔器官脱垂评分(POP-Q)评价盆腔器官脱垂情况。阴道分娩时在第三产程后,取阴道前、后壁粘膜组织和肛提肌组织。肛提肌组织进行组织学染色,观察肛提肌形态学变化、测量肛提肌肌纤维直径并进行分型;阴道粘膜组织分别进行蛋白基因产物9.5(PGP9.5)、血管活性肠肽(VIP)和神经肽Y(NPY)等三种免疫组化染色,镜下分别计数阴道粘膜内三种抗体阳性神经纤维末梢的数目。结果阴道分娩后产妇肛提肌既有神经源性改变也有肌源性改变,既有急性期改变也有慢性期改变。妊娠期和阴道分娩后无论是否有POP,肛提肌组织活检标本中Ⅰ型肌纤维均占优势(妊娠期为78.5%～83.5%,阴道分娩后为78.3%～82.2%),Ⅰ型和Ⅱ型肌纤维的直径和比例在POP和非POP组产妇中无统计学差异(P>0.05)。妊娠期和产后有/无阴道壁脱垂的产妇Ⅰ型肌纤维的直径和Ⅰ型、Ⅱ型肌纤维的比例比较均无统计学差异(P>0.05)。妊娠期阴道后壁脱垂的产妇与妊娠期阴道后壁无脱垂的产妇比较,Ⅱ型肌纤维的直径差异有统计学意义(P<0.05)。产后阴道壁脱垂产妇与产后阴道壁无脱垂产妇比较,阴道壁内血管活性肠肽(VIP)和神经肽Y(NPY)能神经末梢的分布有统计学差异(P<0.05),妊娠期有/无阴道壁脱垂的产妇阴道壁内的神经末梢分布没有统计学差异(P>0.05)。结论产妇肛提肌形态学改变、肌纤维直径以及Ⅰ型和Ⅱ型肌纤维比例的改变,不是引起妊娠期和产后阴道壁脱垂的直接原因。阴道前壁内VIP和NPY能神经纤维末梢分布减少,可能是产后阴道壁脱垂的发生机制之一。

Objective： To investigate the pathologic changes mucosa in women with pelvic organ prolase（POP）. of levator ani musle and innervation of vaginal Methods. One hundred primiparas were collected in the study. Their pelvic organ prolapse（POP）was assessed by the Pelvic Organ Prolapse Quantitative Examination（POP-Q）in the third trimester and around six weeks postpartum. After the third stage of labor,biopsy specimens of levitor ani muscle（LAM）and vagina wall were obtained and stained with histological techniques for examination of morphological characteristics. Vaginal mucosa specimens were stained with the following immunohistochemistry staining： PG-P9.5,vasoactine intrestinal peptide （VIP）and neuropeptide Y （NPY）, and the positive stained nerve fibers were calculated respectively. Results： The LAMs of the puerperal undergoing vaginal delivery presented acute and chronic neurogenetic and myogenetic changes. The type Ⅰ muscular fibers were predominant in patients with and without POP（78.5%-83.5% during pregnancy and 78.3%-82.2% postpartum）. No significant difference was found in diameters and proportion of LAMs between women with and without POP （P〉 0.05）. No difference was observed between puerperants with and without POP concerning the diameters and ratio of muscular fibers（P〉0.05）. There were significant differences in the diameter of type Ⅱ muscular fibers and the innervation of VIP and NPY nerve fibers between puerperants with POP and without POP（P〈0.05）. Conclusions： The changes of morphology, muscular fiber diameters and proportions in LAMs of puerperants were not directly associated with POP postpartum. Different innervation of VIP and NPY nerve fibers in the lamina propria of the anterior vaginal wall may contribute to the pathogenesis of POP after delivery.