Chebil Omar, Behr Michel, Auriault Florent, Arnoux Pierre-Jean
Aix-Marseille Univité, LBA, 13015, Marseille, France,
Med Biol Eng Comput. 2014 Aug;52(8):629-37. doi: 10.1007/s11517-014-1166-6. Epub 2014 Jun 19.
The spleen is a frequently injured abdominal organ in road accidents, with an injury frequency close to 30%. The splenic avulsion exhibit a significant ratio of morbidity. It is clinically described as the complete failure of the pancreatico-splenic ligament (PSL) which is composed of splenic vessels and connective tissues. What are the biomechanical mechanisms involved with spleen avulsion? Is it possible to quantify tolerance levels of PSL structure? The current work combines both experimental and finite element (FE) investigations to determine the splenic avulsion process. Tensile tests on 13 PSL samples were performed up to failure. The experimental results provide reference data for model validation and showed a failure process starting at a peak force of 70±34 N combined with a peak strain of 105±26%. In an attempt to identify possible vessel ruptures within the PSL, a FE model of the PSL was developed including both vessels and connective tissues. The vessel wall behaviour up to failure was reproduced using an Ogden law and calibrated by inverse analysis according to literature data. The connective tissues function was modelled by a cohesion-loss interface. Once model correlation to experimental results was achieved, numerical simulation revealed that haemorrhage could occur even before the maximum peak is reached. Indeed, the first vessel ruptures were recorded at a strain of 92% at the upper lobe vein.
脾脏是道路交通事故中常受损伤的腹部器官，损伤发生率接近30%。脾撕裂伤的发病率相当高。临床上将其描述为胰脾韧带（PSL）的完全断裂，胰脾韧带由脾血管和结缔组织组成。脾撕裂伤涉及哪些生物力学机制？能否量化PSL结构的耐受水平？当前的研究结合了实验和有限元（FE）研究来确定脾撕裂过程。对13个PSL样本进行了拉伸试验直至破坏。实验结果为模型验证提供了参考数据，并显示破坏过程始于70±34 N的峰值力和105±26%的峰值应变。为了确定PSL内可能的血管破裂情况，建立了一个包括血管和结缔组织的PSL有限元模型。使用奥格登定律再现了血管壁直至破坏的行为，并根据文献数据通过反分析进行校准。结缔组织的功能通过内聚力损失界面进行建模。一旦模型与实验结果实现关联，数值模拟显示甚至在达到最大峰值之前就可能发生出血。事实上，首次记录到的血管破裂发生在上叶静脉应变达到92%时。
