OBJECTIVE: To establish the best laser setting of Nd:YAG lasers for pancreatic tissue ablation. A secondary aim was to investigate the prediction capability of a mathematical model on ablation volume.
METHODS: Ex vivo animal study.
METHODS: Hospital animal laboratory.
METHODS: Explanted pancreatic glands from 60 healthy farm pigs.
METHODS: Laser output powers (OP) of 1.5, 3, 6, 10, 15, and 20 W were supplied. Ten trials for each OP were performed under US guidance on ex vivo healthy porcine pancreatic tissue.
METHODS: Ablation volume (Va) and central carbonization volume (Vc) were measured on histologic specimens as the sum of the lesion areas multiplied by the thickness of each slide. The theoretical model of the laser-tissue interaction was based on the Pennes equation.
RESULTS: A circumscribed ablation zone was observed in all histologic specimens. Va values grow with the increase of the OP up to 10 W and reach a plateau between 10 and 20 W. The trend of Vc values rises constantly until 20 W. The theoretical model shows a good agreement with experimental Va and Vc for OP between 1.5 and 10 W.
CONCLUSIONS: Ex vivo study.
CONCLUSIONS: Volumes recorded suggest that the best laser OP could be the lowest one to obtain similar Va with smaller Vc in order to avoid the risk of thermal injury to the surrounding tissue. The good agreement between the two models demonstrates the prediction capability of the theoretical model on laser-induced ablation volume in an ex vivo animal model and supports its potential use for estimating the ablation size at different laser OPs.
目的:建立胰腺组织消融的最佳Nd:YAG激光设置。次要目的是研究数学模型对消融体积的预测能力。
方法:离体动物研究。
方法:医院动物实验室。
方法:从60只健康的农场猪移植胰腺。
方法:提供1.5、3、6、10、15和20W的激光输出功率(OP)。在美国指导下对离体健康猪胰腺组织进行了10项针对每种OP的试验。
方法:在组织学标本上测量消融体积(Va)和中心碳化体积(Vc),作为病变面积的总和乘以每个载玻片的厚度。激光-组织相互作用的理论模型基于Pennes方程。
结果:在所有的组织学标本中都观察到了一个限定的消融区。Va值随着OP的增加而增加到10W,并在10至20W之间达到平稳状态。Vc值的趋势不断上升直到20W。理论模型与OP的实验Va和Vc在1.5至10W之间显示出良好的一致性。
结论:离体研究。
结论:记录的数量表明,最好的激光OP可能是获得具有较小Vc的相似Va的最低激光,以避免对周围组织造成热损伤的风险。两个模型之间的良好一致性证明了理论模型对离体动物模型中激光诱导的消融体积的预测能力,并支持其用于估计不同激光OPs下的消融尺寸的潜在用途。