Enhanced Radiofrequency Ablation With Magnetically Directed Metallic Nanoparticles
Enhanced Radiofrequency Ablation With Magnetically Directed Metallic Nanoparticles
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DOI：
10.1161/circep.115.003820
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发表时间：
2016-05-01
影响因子：
8.4
通讯作者：
Sauer, William H.
中科院分区：
文献类型：
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作者：
Nguyen, Duy T.;Tzou, Wendy S.;Sauer, William H.
背景-先前已经演示了对位于射频消融源附近的金属进行远程加热。因此，用金属纳米粒子处理的心脏组织消融可能会改善局部射频加热并导致更大的消融病灶。我们试图评估磁性纳米颗粒对组织对射频能量敏感性的影响。方法和结果-使用消融导管进行消融，该消融导管以 10 g 的力定位在制备的离体样本上。测量组织温度并获取病变体积。使用体内猪大腿模型来研究射频应用过程中系统输送的磁引导氧化铁 (FeO) 纳米粒子。随后对消融组织进行磁共振成像和组织学染色，作为消融病变分析的一部分。用金属纳米粒子处理的离体心肌组织的消融导致明显更大的病变，具有更大的阻抗变化以及组织内热导率增加的证据。通过磁共振成像和铁染色证明了 Fe3O 纳米粒子在猪大腿标本中的磁引导定位。在 Fe3O 注入和磁引导后，在具有较高 Fe3O 的区域进行冲洗消融，产生了更大的病灶，而蒸汽爆裂的发生率却没有增加。结论——金属纳米颗粒渗透导致显着更大的消融病灶，并改变了电导率和热导率。 Fe3O纳米粒子的体内磁引导可以促进射频消融，而无需直接渗透到目标组织中。需要进一步的研究来评估这种使用金属纳米粒子治疗心律失常的消融策略的临床适用性。
Background-Remote heating of metal located near a radiofrequency ablation source has been previously demonstrated. Therefore, ablation of cardiac tissue treated with metallic nanoparticles may improve local radiofrequency heating and lead to larger ablation lesions. We sought to evaluate the effect of magnetic nanoparticles on tissue sensitivity to radiofrequency energy.Methods and Results-Ablation was performed using an ablation catheter positioned with 10 g of force over prepared ex vivo specimens. Tissue temperatures were measured and lesion volumes were acquired. An in vivo porcine thigh model was used to study systemically delivered magnetically guided iron oxide (FeO) nanoparticles during radiofrequency application. Magnetic resonance imaging and histological staining of ablated tissue were subsequently performed as a part of ablation lesion analysis. Ablation of ex vivo myocardial tissue treated with metallic nanoparticles resulted in significantly larger lesions with greater impedance changes and evidence of increased thermal conductivity within the tissue. Magnet-guided localization of FeO nanoparticles within porcine thigh preps was demonstrated by magnetic resonance imaging and iron staining. Irrigated ablation in the regions with greater FeO, after FeO infusion and magnetic guidance, created larger lesions without a greater incidence of steam pops.Conclusions-Metal nanoparticle infiltration resulted in significantly larger ablation lesions with altered electric and thermal conductivity. In vivo magnetic guidance of FeO nanoparticles allowed for facilitated radiofrequency ablation without direct infiltration into the targeted tissue. Further research is needed to assess the clinical applicability of this ablation strategy using metallic nanoparticles for the treatment of cardiac arrhythmias.