Heskin Leonie, Galvin Rose, Conroy Jack, Traynor Oscar, Madden Stephen, Simms Ciaran
Department of Surgical Affairs, Royal College of Surgeons in Ireland, Ireland.
Department of Physiotherapy, University of Limerick, Ireland.
J Mech Behav Biomed Mater. 2022 Jul;131:105216. doi: 10.1016/j.jmbbm.2022.105216. Epub 2022 Apr 16.
The required fidelity of synthetic materials in surgical simulators to teach tissue handling and repair requirements should be as accurate as possible. There is a poor understanding of the relationship between choice of muscle surrogates and training outcome for trainee surgeons. To address this, the mechanical characteristics of several candidate synthetic muscle surrogates were measured, and their subjective biofidelity was qualitatively assessed by surgeons.
Silicone was selected after assessing several material options and 16 silicone-based surrogates were evaluated. Three of the closest samples to muscle (Samples 1.1, 1.2, 1.3) and one with inserted longitudinal fibres (1.2F) were mechanically tested in the following: compression and tension, needle puncture force and suture pull-out in comparison with real muscle. The four samples were evaluated by 17 Plastic and Orthopaedic surgeons to determine their views of the fidelity with regard to the handling properties, needle insertion and ease of suture pull-out.
The mechanical testing showed the surrogates exhibited varying characteristics that matched some of the properties of muscle, though none recreated all the mechanical characteristics of native muscle. Good biofidelity was generally achieved for compression stiffness and needle puncture force, but it was evident that tensile stiff was too low for all samples. The pull-out forces were variable and too low, except for the sample with longitudinal fibres. In the qualitative assessment, the overall median scores for the four surrogate samples were all between 30 and 32 (possible range 9-45), indicating limited differentiation of the samples tested by the surgeons.
The surrogate materials showed a range of mechanical properties bracketing those of real muscle, thus presenting a suitable combination of candidates for use in simulators to attain the requirements as set out in the learning outcomes of muscle repair. However, despite significant mechanical differences between the samples, all surgeons found the samples to be similar to each other.
手术模拟器中用于教授组织处理和修复要求的合成材料所需的逼真度应尽可能精确。对于实习外科医生而言，人们对肌肉替代物的选择与训练结果之间的关系了解甚少。为了解决这一问题，我们测量了几种候选合成肌肉替代物的力学特性，并由外科医生对其主观生物逼真度进行了定性评估。
在评估了几种材料选项后选择了硅胶，并对16种基于硅胶的替代物进行了评估。将最接近肌肉的三个样本（样本1.1、1.2、1.3）和一个插入纵向纤维的样本（1.2F）与真实肌肉进行比较，进行以下力学测试：压缩和拉伸、针刺力和缝线拔出力。17名整形外科和骨科医生对这四个样本进行了评估，以确定他们对这些样本在操作特性、针刺和缝线拔出难易程度方面逼真度的看法。
力学测试表明，这些替代物表现出不同的特性，与肌肉的某些特性相匹配，尽管没有一种能重现天然肌肉的所有力学特性。压缩刚度和针刺力通常具有良好的生物逼真度，但很明显，所有样本的拉伸刚度都过低。除了带有纵向纤维的样本外，拔出力各不相同且过低。在定性评估中，四个替代物样本的总体中位数分数均在30至32之间（可能范围为9 - 45），表明外科医生测试的样本之间差异有限。
替代材料显示出一系列介于真实肌肉力学性能之间的特性，因此提供了一组合适的候选材料，可用于模拟器以满足肌肉修复学习成果中规定的要求。然而，尽管样本之间存在显著的力学差异，但所有外科医生都发现这些样本彼此相似。
