MRI对分娩并发肛提肌损伤的评价研究

Evaluation on levator ani muscle injuries after vaginal delivery with MRI

目的探讨女性正常肛提肌与肛提肌损伤的 MRI 表现,评价分娩与肛提肌损伤的相关性。方法选择100例健康未产妇(对照组)和200例经阴道分娩初产妇(研究组),研究组进一步分为压力性尿失禁组(研究 A 组)和无症状组(研究 B 组)各100例。采用 MR 质子加权像对其盆部进行多方位扫描,比较正常肛提肌与其损伤的 MRI 特征。结果对照组肛提肌均表现正常,研究组中54例(27%)(研究 A 组42例,研究 B 组12例)有明显的肛提肌损伤,其中49例位于耻骨直肠肌,5例位于髂骨尾骨肌(X^2=41.447,P<0.01)。耻骨直肠肌损伤多表现为单侧或双侧部分缺损,髂骨尾骨肌损伤表现为肌肉明显萎缩。结论经阴道分娩是引起肛提肌损伤的重要原因,其损伤可导致盆腔器官脱垂和盆底功能障碍性疾病,初产妇肛提肌损伤多发生于耻骨直肠肌,MRI 是检测肛提肌损伤的有效手段。

Objective To explore the MRI finding of female normal levator ani muscle and the levator ani muscle injuries and to evaluate the correlation between childbirth and levator ani muscle injuries. Methods One hundred asymptomatic nulliparous women （control group ） and 200 vaginally primiparous women （study group） were selected as the object of this study. Moreover, the study group was divided into two subgroups： group A （100 cases） with stress incontinence, group B （100 cases） without clinical symptoms. Multiplanar proton density magnetic resonance images were obtained at 0. 5 cm intervals from these study individuals. All images were used to analyze the differentiation of MRI features between normal levator ani muscle and levator ani muscle injuries. Results No levator ani injuries were identified in the control group. Fifty-four primiparous women （27%） had visible injuries in their levator ani muscles, 42 in group A and 12 in group B. Injuries were identified in the puborectalis muscle in 49 cases and in the iliococcygeus muscle in 5 cases（x^2 = 41. 447, P 〈 0. 01 ）. Within the puborectalis muscle, both unilateral and bilateral partial defects were usually found. Iliococcygeus injuries showed that the iliococcygeus muscle was atrophied in MR images. Conclusion Vaginal delivery was an important cause of the levator ani muscle injuries which could result in pelvic floor dysfunction and pelvic organs prolapsed. MRI was an effective examination method of the levator ani muscle injuries.