Department of Obstetrics and Gynecology, University Hospital, Goethe University Frankfurt am Main, Frankfurt, Hessen, Germany.
Department of Obstetrics and Gynecology, Buergerhospital - Dr. Senckenberg Foundation, Nibelungenallee 37-41, 60318, Frankfurt am Main, Hessen, Germany.
Arch Gynecol Obstet. 2021 Dec;304(6):1485-1491. doi: 10.1007/s00404-021-06074-y. Epub 2021 Apr 23.
We aim to describe the sonographic uterine anatomy after a cesarean section (CS), test the reproducibility of predefined measurements from the BSUM study, and report the distribution of these measurements.
This is a descriptive observational study where 200 women with a history of only one CS were recruited 12-24 months postoperatively. A 5-13 MHz micro-convex transvaginal transducer was used for the acquisition of volumetric datasets for evaluating the CS scars. We defined 15 distinct measurements including the residual myometrial thickness (RMT). RMT ratio was calculated as a percentage of RMT to the assumed pre-cesarean anterior uterine wall thickness. A P value below 0.05 is utilized for significant statistical analysis.
Patients were included on average 18.5 months post-cesarean. The uterus was anteflexed in 82.5% and retroflexed in 17.5%. Myometrial defects at the site of CS manifest in two forms, either as a niche or as fibrosis. Patients are classified into four groups: those with isolated niches (45%), combined niches and fibrosis (38.5%), isolated fibrosis (11%), and lacking both (5%). The median RMT ratio for these groups was 63.09, 40.93, 59.84, and 100% with a standard deviation of 16.73, 12.95, 16.59, and 0, respectively. The interclass correlation coefficient (ICC) remained above 0.9 for all distinct measurements among these groups except for those of RMT, where ICC varied between 0.47 and 0.96. The RMT ratio shows a constant ICC at 0.94 regardless of the group.
The post-cesarean uterus is often anteflexed, and a myometrial loss of about 50% is normally expected. The pattern of this loss is in the form of a predominantly sharp-edged and echogenic niche, fibrosis, or a combination of both. The proposed RMT ratio takes these changes into consideration and results in a reproducible quantification. We hypothesize that different adverse outcomes could be attributed to the different scar patterns.
本研究旨在描述剖宫产术后的子宫超声解剖结构，检验 BSUM 研究中预定义测量的可重复性，并报告这些测量的分布情况。
这是一项描述性观察研究，共纳入 200 例仅行过 1 次剖宫产的女性，术后 12-24 个月进行研究。使用 5-13MHz 微凸经阴道探头获取评估剖宫产瘢痕的容积数据集。我们定义了 15 个不同的测量值，包括残余子宫肌层厚度（RMT）。RMT 比值定义为 RMT 与假定剖宫产术前子宫前壁厚度的百分比。P 值<0.05 用于具有统计学意义的分析。
患者平均在剖宫产术后 18.5 个月入组。子宫前屈 82.5%，后屈 17.5%。CS 部位的子宫肌层缺陷以两种形式表现，即憩室或纤维化。患者分为 4 组：单纯憩室（45%）、憩室合并纤维化（38.5%）、单纯纤维化（11%）和两者均无（5%）。这些组的 RMT 比值中位数分别为 63.09%、40.93%、59.84%和 100%，标准差分别为 16.73%、12.95%、16.59%和 0。除 RMT 外，所有组之间的其他特定测量的组内相关系数（ICC）均>0.9，ICC 介于 0.47-0.96 之间。RMT 比值在任何组中均保持一致的 ICC 值为 0.94。
剖宫产术后子宫常呈前屈位，通常预期子宫肌层损失约 50%。这种损失的模式表现为主要为锐边和高回声憩室、纤维化或两者的组合。提出的 RMT 比值考虑到了这些变化，从而实现了可重复的定量。我们假设不同的不良结局可能归因于不同的瘢痕模式。
