利用有限元分析预警经阴道分娩瘢痕子宫破裂风险

目的 应用有限元法分析瘢痕子宫受力与瘢痕厚度及位置的关系,研究瘢痕子宫破裂风险因素.方法 首先基于孕期为40周孕妇子宫尺寸应用SolidWorks建立瘢痕厚度和位置可变的子宫三维模型,然后在ANSYS软件中设置宫内压力,压力范围为4.83～ 23.9 kPa,计算子宫受力.结果 在宫缩过程中,最大应力位于子宫瘢痕处,瘢...

Rupture Warning of Scar Uterus in Vaginal Delivery by Finite Element Analysis

Objective To analyze the relationship between scar uterine stress and scar thickness/position by using finite element method, so as to study risk factors of scar uterus rupture. Methods Firstly, SolidWorks was used to establish a three-dimensional (3D) model of the uterus with variable scar thickness and position based on uterine size of the pregnant woman at 40th week of gestation, and then the intrauterine pressure was set in the ANSYS software with pressure range of 4.83-23.9 kPa to calculate the uterine stress. Results During the contraction process, the maximum stress was located in uterine scar, the maximum stress on the uterus with scar thickness smaller than 3 mm was greater than tensile strength of the uterus; 3 mm was used as thickness limit of the lower uterine body. If the thickness was smaller than 3 mm, cesarean section should be selected immediately. Otherwise, transvaginal delivery could be selected. When the scar thickness was 3.0 mm, the maximum stress experienced by the uterus decreased at first and then increased with the distance from the uterine floor increasing. The stress at the uterine scar was the smallest when the distance from the uterine floor was 295 mm; when the scar was 285-305 mm from the uterine floor, the ultimate stress on the scar was smaller than its tensile strength, and it was safer to choose a vaginal delivery. Conclusions Risk factors of scar uterine rupture were studied based on ANSYS finite element analysis. The analysis results were consistent with the clinical data, which provided analysis method and theoretical guidance for the choice of delivery method in clinic.