Data Sheet 1_Evaluation of intestinal tissue safety during the compression process of circular end-to-end anastomosis stapler based on finite element simulation.docx

ObjectiveCurrently, there is no standardized finite element analysis method for investigating the safe compression range of circular end-to-end anastomosis stapler. This study aims to develop a finite element analysis framework based on stress thresholds and the volumetric distribution of tissue states, and to investigate the effects of tissue thickness and compression ratio on the risk of compression-induced injury during anastomosis. The evaluation is conducted by calculating the proportion of the volume of elements categorized as “effective fixation” or “damaged” based on equivalent stress.
MethodsA disposable circular end-to-end anastomosis stapler was used as the reference model to create a 1:1 scale 3D model of the key components at the contact surface, including the anvil, staple cartridge, and cutting washer. Finite element models of intestinal tissue with varying thicknesses were established within the environment of the circular stapler. Different compression ratios were applied to analyze the stress distribution in the intestinal tissue.
ResultsAcross experiments with intestinal tissues of all thicknesses, the safe compression ratio consistently centered around 60%. The maximum equivalent stress on the lower intestinal segment was always greater than that on the upper segment, while the average equivalent stress of the upper and lower intestinal segments exhibited a collinear distribution across experiments with varying tissue thickness. An increase in total tissue thickness positively contributed to the expansion of the safe compression range. In asymmetric tissue thickness models, the side with greater thickness demonstrated a broader safe compression range.
ConclusionThe safe compression range of staplers is closely related to the properties and thickness of the tissue. This study provides a framework for simulating and determining the safe compression range of staplers.

研究目标：目前尚无标准化的有限元分析（finite element analysis）方法，用于探究圆形端端吻合器（circular end-to-end anastomosis stapler）的安全压缩范围。本研究旨在构建基于应力阈值与组织状态体积分布的有限元分析框架，探讨组织厚度与压缩比对吻合过程中压迫性损伤风险的影响。本研究通过基于等效应力（equivalent stress）将单元划分为「有效固定」或「损伤」两类，并计算两类单元的体积占比，完成相关评估。

研究方法：本研究以一次性圆形端端吻合器为参考模型，构建其接触面关键部件的1:1比例三维模型，包括抵钉座（anvil）、钉仓（staple cartridge）与切割垫圈（cutting washer）。在该圆形吻合器的建模环境中，构建不同厚度的肠道组织有限元模型；设置不同压缩比，分析肠道组织内的应力分布情况。

研究结果：在所有厚度肠道组织的实验中，安全压缩比均集中在60%左右。肠道下段的最大等效应力始终高于上段；而在不同组织厚度的实验中，上下两段肠道的平均等效应力均呈现共线性分布。组织总厚度的增加可显著扩大安全压缩范围。在组织厚度不对称的模型中，厚度更大的一侧拥有更宽的安全压缩范围。

研究结论：吻合器的安全压缩范围与组织特性及厚度密切相关。本研究为模拟并确定吻合器的安全压缩范围提供了一套标准化分析框架。