New Technologies - Research Centre, University of West Bohemia, Pilsen, Czech Republic.
Department of Obstetrics and Gynecology, University Hospital, Pilsen, Czech Republic.
Int Urogynecol J. 2021 Jul;32(7):1997-2003. doi: 10.1007/s00192-021-04769-z. Epub 2021 Apr 2.
Several studies have assessed birth-related deformations of the levator ani muscle (LAM) and perineum on models that depicted these elements in isolation. The main aim of this study was to develop a complex female pelvic floor computational model using the finite element method to evaluate points and timing of maximum stress at the LAM and perineum in relation to the birth process.
A three-dimensional computational model of the female pelvic floor was created and used to simulate vaginal birth based on data from previously described real-life MRI scans. We developed three models: model A (LAM without perineum); model B (perineum without LAM); model C (a combined model with both structures).
The maximum stress in the LAM was achieved when the vertex was 9 cm below the ischial spines and measured 37.3 MPa in model A and 88.7 MPa in model C. The maximum stress in the perineum occurred at the time of distension by the suboocipito-frontal diameter and reached 86.7 MPa and 119.6 MPa in models B and C, respectively, while the stress in the posterior fourchette caused by the suboccipito-bregmatic diameter measured 36.9 MPa for model B and 39.8 MPa for model C.
Including perineal structures in a computational birth model simulation affects the level of stress at the LAM. The maximum stress at the LAM and perineum seems to occur when the head is lower than previously anticipated.
已有多项研究使用单独描绘这些元素的模型评估了会阴裂伤和肛提肌（LAM）的分娩相关性变形。本研究的主要目的是利用有限元方法开发一个复杂的女性盆底计算模型，以评估与分娩过程相关的 LAM 和会阴的最大应力点和时间。
我们创建了一个女性盆底的三维计算模型，并根据先前描述的真实生活 MRI 扫描数据来模拟阴道分娩。我们开发了三种模型：A 型（无会阴的 LAM）；B 型（无 LAM 的会阴）；C 型（同时包含这两个结构的组合模型）。
在顶点低于坐骨棘 9 厘米时，LAM 中的最大应力达到 37.3 MPa（在模型 A 中）和 88.7 MPa（在模型 C 中）。会阴的最大应力发生在枕额径扩张时，B 型和 C 型分别达到 86.7 MPa 和 119.6 MPa，而枕骨大孔径引起的后四陷窝的应力在 B 型和 C 型中分别为 36.9 MPa 和 39.8 MPa。
在计算分娩模型模拟中包含会阴结构会影响 LAM 的应力水平。LAM 和会阴的最大应力似乎出现在头部低于先前预期的位置。
