Abstract

Purpose: In this study, we developed a novel nitinol-actuated surgical instrument to conduct laparoscopic renal denervation for the treatment of resistant hypertension. We investigated whether shape and temperature settings of nitinol specimens fit well into the design goals. Furthermore, we conducted a pilot study to validate the mechanical and physiological performance of nerve ablation without damaging the renal artery.

Method: Tensile tests were performed to observe temperature-dependent thermomechanical properties and the original shape of nitinol specimens was set considering our design goal. We performed strain gage experiments to measure bending strain. We developed surgical instrument and operated laparoscopic renal denervation in a swine model. Subsequent impedance spectroscopy experiments were conducted to measure changes in impedance magnitudes during the operation and histological analyses were performed to visualize thermogenic damage to arteries and nerves.

Results: Tensile testing showed that the shape memory effect begins above 37 °C. Measured strains on nitinol surfaces were 2.10% ± 0.769%, below the strain limit of 8%. Impedance spectroscopy experiments showed decreases in magnitude in all six trials. After operation of laparoscopic renal denervation following the protocol, renal arteries and nerves were harvested and thermogenic damage was observed in nerves but not arteries.

Conclusion: We developed a novel nitinol-actuated surgical instrument with which to perform laparoscopic renal denervation. The feasibility of our device was verified using thermomechanical analyses of nitinol, and assessments of mechanical and physiological performance. Our device could be used in other laparoscopic procedures that require large degrees of freedom while restricting to trocar size.

摘要

目的：在这项研究中，我们开发了一种新型的镍钛合金致动的手术器械，可进行腹腔镜肾脏去神经支配治疗顽固性高血压。我们调查了镍钛合金样品的形状和温度设置是否完全符合设计目标。此外，我们进行了一项初步研究，以验证神经消融的机械和生理功能，而不会损坏肾动脉。

方法：进行拉伸试验以观察温度相关的热机械性能，并根据我们的设计目标设定镍钛合金样品的原始形状。我们进行了应变计实验以测量弯曲应变。我们开发了外科手术器械并在猪模型中进行了腹腔镜肾脏去神经。随后进行了阻抗谱实验，以测量手术过程中阻抗幅度的变化，并进行了组织学分析以可视化对动脉和神经的热损伤。

结果：拉伸测试表明形状记忆效应开始于37°C以上。镍钛诺表面测得的应变为2.10％±0.769％，低于8％的应变极限。阻抗谱实验表明，在所有六个试验中幅度都减小了。按照该方案进行腹腔镜肾去神经手术后，收获肾动脉和神经，并在神经而非动脉中观察到热源性损伤。

结论：我们开发了一种新型的镍钛合金致动的手术器械，可用于执行腹腔镜肾去神经。我们的设备的可行性通过镍钛合金的热机械分析以及机械和生理性能评估得到了验证。我们的设备可用于其他需要大量自由度并限制套管针尺寸的腹腔镜手术。