van der Steen Annemarie, De Alba Alvarez Irina, Simonis Frank F J, Grob Anique T M, van den Noort Frieda
Department of Gynecology, Ziekenhuisgroep Twente, Hengelo, The Netherlands; Multi-Modality Medical Imaging (M3I), TechMed Centre, University of Twente, Enschede, The Netherlands.
Multi-Modality Medical Imaging (M3I), TechMed Centre, University of Twente, Enschede, The Netherlands.
Am J Obstet Gynecol. 2025 Aug 21. doi: 10.1016/j.ajog.2025.08.013.
Pessary treatment is a popular option for women with pelvic organ prolapse; however, success rates are limited, mostly due to dislodgement of the pessary. In literature, several support mechanisms are proposed such as support by the levator ani muscle and the uterus which acts as a lever to keep the pessary in place. To improve success rates of pessary therapy, the support mechanism should be further investigated.
The aim of this study is to identify ring-shaped pessary support mechanisms by comparing upright magnetic resonance imaging data of successful and unsuccessful pessary users.
Upright magnetic resonance scans were performed after obtaining informed consent in patients with and without pessary in 30 successful and 29 unsuccessful cases. The study was approved by the medical ethics committee. We analyzed the position of the pessary with respect to the levator ani muscle, the pubic symphysis, and the uterus. For comparison of the levator ani muscle position with respect to the pessary, principal component analysis was used. Statistical analyses were performed using SPSS version 29.0.1.0 (SPSS, Chicago, IL). Differences between the groups were analyzed using a 2-sided t-test or Mann-Whitney U test where appropriate for the continuous data. For the categorical data, a chi-square test was performed.
The pessary is significantly lower in the pelvis in the unsuccessful group (median 1.9 cm below the Pelvic Inclination Correction System (PICS) line [range, -0.9; 4.0]) than in the successful group (median 0.6 cm below the PICS line [range, -1.8; 2.6]). The angles of the pessary with respect to the PICS line, and the distances of bladder and uterus to the PICS line, showed no significant difference between groups. The first principal component of the levator ani muscle shows a significantly lower position of the pessary in the levator ani muscle for the unsuccessful group (P<.001) and accounted for 64.8% of shape variation. With regards to the uterus position, in the successful group, the cervix is in the center of the pessary, with the proximal edge of the pessary positioned in the posterior fornix. While in the unsuccessful group, the cervix is located near the proximal edge of the pessary. Additionally, the unsuccessful group had 7 women with a hysterectomy, compared to none in the successful group, although this was not part of the inclusion/exclusion criteria.
These findings support the hypothesis that the pessary is kept in place by the levator ani muscle and the uterus lever mechanism. Knowledge on these support mechanisms can guide development of new pessary shapes or even personalized pessaries for unsuccessful users.
子宫托治疗是盆腔器官脱垂女性常用的治疗方法；然而，成功率有限，主要原因是子宫托移位。文献中提出了几种支撑机制，如肛提肌的支撑作用以及子宫作为杠杆保持子宫托在位。为提高子宫托治疗的成功率，应进一步研究支撑机制。
本研究旨在通过比较使用子宫托成功和失败患者的直立磁共振成像数据，确定环形子宫托的支撑机制。
在获得知情同意后，对30例使用子宫托成功和29例使用子宫托失败的患者进行了直立磁共振扫描，有无子宫托的患者均纳入。该研究经医学伦理委员会批准。我们分析了子宫托相对于肛提肌、耻骨联合和子宫的位置。为比较肛提肌相对于子宫托的位置，使用了主成分分析。使用SPSS 29.0.1.0版软件（SPSS，伊利诺伊州芝加哥）进行统计分析。对于连续数据，在适当情况下使用双侧t检验或曼-惠特尼U检验分析组间差异。对于分类数据，进行卡方检验。
失败组子宫托在盆腔中的位置明显低于成功组（中位数在骨盆倾斜度校正系统（PICS）线以下1.9 cm [范围，-0.9；4.0]），成功组中位数在PICS线以下0.6 cm [范围，-1.8；2.6]）。子宫托相对于PICS线的角度以及膀胱和子宫到PICS线的距离，两组间无显著差异。肛提肌的第一主成分显示，失败组子宫托在肛提肌中的位置明显更低（P<0.001），占形状变异的64.8%。关于子宫位置，成功组中，宫颈位于子宫托中心，子宫托近端边缘位于后穹窿。而在失败组中，宫颈位于子宫托近端边缘附近。此外，失败组有7名女性接受了子宫切除术，成功组无，尽管这不是纳入/排除标准的一部分。
这些发现支持了子宫托通过肛提肌和子宫杠杆机制保持在位的假说。了解这些支撑机制可为失败使用者开发新的子宫托形状甚至个性化子宫托提供指导。
