经阴道分娩后压力性尿失禁产妇盆底结构改变的MRI研究

Pelvic floor structural alterations in primiparas with stress urinary incontinence after vaginal delivery:A MRI study

目的探讨经阴道分娩后压力性尿失禁产妇盆底结构改变情况。方法前瞻性收集2015年3月—2016年4月间于我院产科进行产后盆底复查的经阴道分娩初产妇44例,包括尿失禁组19例,正常组25例和对照组17例。受试者均行盆腔静、动态MRI检查。由2名放射科医师测量及评估受试者静息期和力排期盆底结构改变情况,指标包括肛提肌裂隙面积(LHA)、H线、M线、膀胱颈至耻骨尾骨线(PCL)距离(B-PCL)、宫颈至PCL的距离(U-PCL)、膀胱尿道后角(RVA)、尿道前倾角(AUA)、提肛板角(LPA)、尿道高度(D)、膀胱颈至耻骨长轴中线的距离(S)和膀胱漏斗存在与否。采用组内相关系数(ICC)评估2名医师各指标测量结果的一致性。采用单因素方差分析比较3组间各测量指标差异,进一步组间两两比较采用Scheffe检验。采用卡方检验比较3组间膀胱漏斗出现比例差异。结果力排期,尿失禁组LHA、H线、M线、RVA、AUA均大于正常组和对照组(均P<0.05),尿失禁组LPA大于对照组(P<0.05),B-PCL、U-PCL、D、S小于正常组和对照组(均P<0.05),而正常组与对照组各测量指标差异均无统计学意义(均P>0.05)。静息期,尿失禁组LHA、RVA大于对照组,B-PCL、D小于对照组(均P<0.05)。尿失禁组存在膀胱漏斗比例为78.95%(15/19),正常组为4%(1/25),对照组为0(0/17),3组间差异有统计学意义(χ~2=39.72,P<0.001)。结论经阴道分娩产后尿失禁者盆底结构改变显著,提示不同程度的肛提肌功能减低、尿道活动度增加、尿道内口闭合完整性差、尿道扩约肌能力不足等病理状态,MRI能够综合评估病变的程度和范围,动态观察盆底结构恢复或进展程度。

Objective To investigate the changes of the pelvic floor structure in primiparas suffering from stress uri-nary incontinence after vaginal delivery. Methods Forty-four primiparas under postpartum review at obstetrics department were prospectively collected in this study during March 2015-April 2016 in our hospital. Ninteen primiparas suffering from stress urinary incontinence （SUI） after vaginal delivery were selected as SUI group, 25 normal primiparas after vaginal deliv-ery were selected as Non-SUI control group, and 17 nulliparous women were selected as the normal control （NC） group. All the subjects underwent static and dynamic MRI. Two radiologists evaluated and measured the parameters of pelvic floor structures, during rest and strain state, including levator ani hiatus area （LHA）, H line, M line, the distance from neck of bladder to PCL （B-PCL）, the distance from cervix to PCL （U-PCL）, retro vesicourethral angle （RVA）, anterior angle of urethra （AUA）, lev-ator ani plate angle （LPA）, urethral height （D）, the distance from bladder neck to the midline of the long axis of pubis （S） and if there was bladder funnel. The measurements consistency between the two observers were calculated by intra-class correla-tion coefficient （ICC）, one-way ANOVA was used to compare the difference of all the measurements among three groups and post-hoc Scheffe test was used in the paired comparisons. Besides, the different proportion of bladder funnel in the three groups were compared by chi-square test. Results In the strain state, the measurements including LHA, H line, M line, RVA, AUA in the SUI group were significant larger than that in the Non-SUI and NC groups （all P〈0.05）, and LPA in the SUI group was also larger than that in the NC group （P〈0.05）. Meanwhile, the B-PCL, U-PCL, D, and S in the SUI group were significant smaller than that in the Non-SUI and NC groups （all P〈0.05）. There were no significant difference in all the measurements between the Non-SUI and NC groups （all P〉0.05）. In the rest state, the measurements of LHA, RVA in the SUI group were larger, and the B-PCL, D were smaller than that in the NC group （all P〈0.05）. The proportion of bladder funnel in three group were 78.95％ （SUI group） , 4％ （Non-SUI group）, 0％ （NC group）, respectively, which showed significant differ ence （χ2=39.72, P〈0.001）. Conclusion Pelvic floor structures change significantly in the primipara suffering from SUI after vaginal delivery, implying some degree of levator ani muscle dysfunction, urethral activity increasing, internal urethral orifice with a poor closed integrity, urethral sphincter disability and a series of pathological state. MRI can be used to evaluate the degree and range of lesions comprehensively, and observe recovery or progress of pelvic floor structure after delivery dynamically.