Nau William H, Diederich Chris J, Shu Richard, Kinsey Adam, Bass Elisa, Lotz Jeff, Hu Serena, Simko Jeff, Ferrier William, Sutton Jeff, Attawia Mohamed, Pellegrino Richard
Thermal Therapy Research Group, Department of Radiation Oncology, University of California, San Francisco, San Francisco, CA 94143-1708, USA.
Spine (Phila Pa 1976). 2007 Mar 1;32(5):503-11. doi: 10.1097/01.brs.0000256905.39488.c7.
In vivo investigation of intradiscal ultrasound thermal therapy in ovine cervical spine model.
To evaluate the potential of interstitial ultrasound for selective heating of intradiscal tissue in vivo.
Application of heat in the spine using resistive wire and radiofrequency current heating devices is currently being used clinically for minimally invasive treatment of discogenic low back pain. Treatment temperatures are representative of those required for thermal necrosis of ingrowing nociceptor nerve fibers and disc cellularity alone, or with coagulation and restructuring of anular collagen in the high temperature case.
Two interstitial ultrasound applicator design configurations with directional heating patterns were evaluated in vivo in ovine cervical intervertebral discs (n = 62), with up to 45-day survival periods. Two heating protocols were employed in which the temperature measured 5 mm away from the applicator was controlled to either <54 C (capable of nerve and cellular necrosis) or >70 C (for coagulation of collagen) for a 10-minute treatment period. Transient and steady state temperature maps, calculated thermal doses (t43), and histology were used to assess the thermal treatments.
These studies demonstrated the capability to control spatial temperature distributions within selected regions of the in vivo intervertebral disc and anular wall using interstitial ultrasound.
Ultrasound energy is capable of penetrating within the highly attenuating disc tissue to produce more extensive radial thermal penetration, lower maximum intradiscal temperature, and shorter treatment times than can be achieved with current clinical intradiscal heating technology. Thus, interstitial ultrasound offers potential as a more precise and faster heating modality for the clinical management of low back pain and studies of thermal effects on disc tissue in animal models.
在羊颈椎模型中对椎间盘内超声热疗进行体内研究。
评估间质超声在体内对椎间盘组织进行选择性加热的潜力。
目前临床上正在使用电阻丝和射频电流加热装置在脊柱中施加热量，用于微创治疗椎间盘源性下腰痛。治疗温度代表了仅使向内生长的伤害性感受器神经纤维和椎间盘细胞发生热坏死所需的温度，或者在高温情况下使纤维环胶原蛋白发生凝固和重塑所需的温度。
在羊颈椎椎间盘（n = 62）中对两种具有定向加热模式的间质超声探头设计配置进行了体内评估，存活期长达45天。采用了两种加热方案，在10分钟的治疗期内，将距探头5毫米处测得的温度控制为<54℃（能够导致神经和细胞坏死）或>70℃（用于胶原蛋白的凝固）。使用瞬态和稳态温度图、计算出的热剂量（t43）以及组织学来评估热疗效果。
这些研究证明了使用间质超声能够控制体内椎间盘和纤维环壁选定区域内的空间温度分布。
与当前临床椎间盘加热技术相比，超声能量能够穿透高度衰减的椎间盘组织，以产生更广泛的径向热穿透、更低的椎间盘内最高温度以及更短的治疗时间。因此，间质超声作为一种更精确、更快的加热方式，在临床治疗下腰痛以及动物模型中研究热对椎间盘组织的影响方面具有潜力。
