Diffusing, Side-Firing, and Radial Delivery Laser Balloon Catheters for Creating Subsurface Thermal Lesions in Tissue.
Diffusing, Side-Firing, and Radial Delivery Laser Balloon Catheters for Creating Subsurface Thermal Lesions in Tissue.
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扩散、侧射和径向传输激光球囊导管，用于在组织中产生表面下热损伤。
DOI：
10.1117/12.2208132
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Fried,NathanielM
中科院分区：
文献类型：
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作者：
Chang,Chun-Hung;Fried,NathanielM
红外激光已被用于与应用冷却方法相结合，以保持在整容手术中的表层皮肤层。类似地，组合的激光照射和组织冷却也可以允许开发皮肤科以外的微创激光疗法。本研究比较了使用近红外激光和应用接触冷却在离体组织中创建皮下损伤的漫射、侧射和径向输送激光球囊导管设计。波长为1075 nm的镱光纤激光器通过定制的18 Fr（6 mm-OD）球囊导管输送能量，球囊导管包含10 mm长的扩散光纤头端、90度侧射光纤或径向输送锥形镜，并通过中心管腔。使冷却的溶液流过单独的管腔进入9 mm直径的球囊中，以使探针保持在7°C冷却。使用猪肝组织样本作为初步组织模型，用于立即观察热损伤的产生。扩散纤维产生了49.3 ± 10.0 mm 2的亚表面热损伤，并保留了0.8 ± 0.1 mm的表面组织。侧射纤维产生2.4 ± 0.9 mm 2直径的表面下热损伤，并保留0.5 ± 0.1 mm的表面组织。径向输送探头组件未能产生表面下热损伤，可能是由于组织表面的有效光斑直径较小，限制了光学穿透深度。最佳激光功率和照射时间测得的扩散光纤和1.4 W和20 s，侧烧光纤，分别为15 W和100 s。扩散和侧射激光球囊导管设计在组织中提供了表面下热损伤。然而，两种设计中的发散激光束限制了保留较厚组织表面层的能力。可能需要进一步优化激光和冷却参数，以保留较厚的表面组织层。
Infrared lasers have been used in combination with applied cooling methods to preserve superficial skin layers during cosmetic surgery. Similarly, combined laser irradiation and tissue cooling may also allow development of minimally invasive laser therapies beyond dermatology. This study compares diffusing, side-firing, and radial delivery laser balloon catheter designs for creation of subsurface lesions in tissue, ex vivo, using a near-IR laser and applied contact cooling. An Ytterbium fiber laser with 1075 nm wavelength delivered energy through custom built 18 Fr (6-mm-OD) balloon catheters incorporating either 10-mm-long diffusing fiber tip, 90 degree side-firing fiber, or radial delivery cone mirror, through a central lumen. A chilled solution was flowed through a separate lumen into 9-mm-diameter balloon to keep probe cooled at 7°C. Porcine liver tissue samples were used as preliminary tissue model for immediate observation of thermal lesion creation. The diffusing fiber produced subsurface thermal lesions measuring 49.3 ± 10.0 mm2 and preserved 0.8 ± 0.1 mm of surface tissue. The side-firing fiber produced subsurface thermal lesions of 2.4 ± 0.9 mm2 diameter and preserved 0.5 ± 0.1 mm of surface tissue. The radial delivery probe assembly failed to produce subsurface thermal lesions, presumably due to the small effective spot diameter at the tissue surface, which limited optical penetration depth. Optimal laser power and irradiation time measured 15 W and 100 s for diffusing fiber and 1.4 W and 20 s, for side-firing fiber, respectively. Diffusing and side-firing laser balloon catheter designs provided subsurface thermal lesions in tissue. However, the divergent laser beam in both designs limited the ability to preserve a thicker layer of tissue surface. Further optimization of laser and cooling parameters may be necessary to preserve thicker surface tissue layers.