■磁共振引导聚焦超声(MRgFUS)热消融是一种有效的非侵入性超声疗法,可以破坏体内猪肌腱,但容易引起皮肤灼伤。我们评估了一种新型混合方案的安全性,该方案通过结合长脉冲聚焦超声和热消融来最大程度地减少热扩散。
■在两项研究中,将15至20kg约克郡猪的体内跟腱(混合N=15,仅热消融N=21)随机分配到6个治疗组。第一个(N=21)是消融(600、900或1200J)。第二个(N=15)是混合的:脉冲FUS(13.5MPa峰值负压),然后消融(600、900或1200J)。测量踝关节的活动范围,肌腱温度,热剂量(240CEM43),并对两组进行皮肤烧伤评估。
■破裂在两种方案之间具有可比性:1/5(20%),混合协议的5/5(100%)和5/5(100%),与2/7(29%)相比,能量为600、900和1200J的仅消融方案为6/7(86%)和7/7(100%),分别。混合协议产生了较低的最高温度,较小的热剂量区域,减少对皮肤的热损伤,更少的全层皮肤烧伤。混合方案的热损伤面积的标准偏差也较小,表明更大的可预测性。
■本研究表明,结合长脉冲FUS和热消融的混合MRgFUS方案比仅用于体外体内肌腱断裂的消融方案不逊色且更安全,可用于非侵入性释放收缩肌腱。
UNASSIGNED: Magnetic Resonance-guided Focused Ultrasound (MRgFUS) thermal ablation is an effective noninvasive ultrasonic therapy to disrupt in vivo porcine tendon but is prone to inducing skin burns. We evaluated the safety profile of a novel hybrid protocol that minimizes thermal spread by combining long-pulse focused ultrasound followed by thermal ablation.
UNASSIGNED: In-vivo Achilles tendons (hybrid N = 15, thermal ablation alone N = 21) from 15 to 20 kg Yorkshire pigs were randomly assigned to 6 treatment groups in two studies. The first (N = 21) was ablation (600, 900, or 1200 J). The second (N = 15) was hybrid: pulsed FUS (13.5 MPa peak negative pressure) followed by ablation (600, 900, or 1200 J). Measurements of ankle range of motion, tendon temperature, thermal dose (240 CEM43), and assessment of skin burn were performed in both groups.
UNASSIGNED: Rupture was comparable between the two protocols: 1/5 (20%), 5/5 (100%) and 5/5 (100%) for hybrid protocol, compared to 2/7 (29%), 6/7 (86%) and 7/7 (100%) for the ablation-only protocol with energies of 600, 900, and 1200 J, respectively. The hybrid protocol produced lower maximum temperatures, smaller areas of thermal dose, fewer thermal injuries to the skin, and fewer full-thickness skin burns. The standard deviation for the area of thermal injury was also smaller for the hybrid protocol, suggesting greater predictability.
UNASSIGNED: This study demonstrated a hybrid MRgFUS protocol combining long-pulse FUS followed by thermal ablation to be noninferior and safer than an ablation-only protocol for extracorporeal in-vivo tendon rupture for future clinical application for noninvasive release of contracted tendon.