Department of Otolaryngology-Head and Neck Surgery, McGill University, Montreal, Quebec, Canada.
JAMA Otolaryngol Head Neck Surg. 2013 Aug 1;139(8):828-33. doi: 10.1001/jamaoto.2013.3974.
Despite significant advances in surgery, most surgical tools remain basic. Lasers provide a means of precise surgical ablation, but their clinical use has remained limited because of undesired thermal, ionizing, or acoustic stress effects leading to tissue injury. A novel ultrafast, nonionizing, picosecond infrared laser (PIRL) system has recently been developed and is capable, in theory, of ablation with negligible thermal or acoustic stress effects.
To measure and compare heat generation by means of thermography during ablation of ex vivo porcine skin by conventional microsecond-pulsed erbium:YAG (Er:YAG) laser and picosecond infrared laser (PIRL).
This study was conducted in an optics laboratory and used a pretest-posttest experimental design comparing 2 methods of laser ablation of tissue with each sample acting as its own control.
Ex vivo porcine skin was ablated in a 5-mm line pattern with both Er:YAG laser and PIRL at fluence levels marginally above ablation threshold (2 J/cm² and 0.6 J/cm², respectively).
Peaks and maxima of skin temperature rises were determined using a thermography camera. Means of peak temperature rises were compared using the paired sample t test. Ablation craters were assessed by means of digital microscopy. RESULTS Mean peak rise in skin surface temperature for the Er:YAG laser and PIRL was 15.0°C and 1.68°C, respectively (P < .001). Maximum peak rise in skin surface temperature was 18.85°C for the Er:YAG laser and 2.05°C for the PIRL. Ablation craters were confirmed on digital microscopy.
Picosecond infrared laser ablation results in negligible heat generation, considerably less than Er:YAG laser ablation, which confirms the potential of this novel technology in minimizing undesirable thermal injury associated with lasers currently in clinical use.
尽管手术技术取得了重大进展，但大多数手术工具仍然很基础。激光提供了一种精确的手术消融手段，但由于不理想的热、电离或声应力效应导致组织损伤，其临床应用仍然受到限制。一种新型超短、非电离、皮秒红外激光（PIRL）系统最近已经开发出来，理论上可以实现几乎没有热或声应力效应的消融。
通过热成像测量和比较离体猪皮在传统微秒脉冲铒：钇铝石榴石（Er:YAG）激光和皮秒红外激光（PIRL）消融过程中的产热情况。
本研究在光学实验室进行，采用预测试后实验设计，用两种激光消融组织的方法对每个样本进行自身对照。
离体猪皮以 5mm 线图案进行消融，Er:YAG 激光和 PIRL 的能量密度略高于消融阈值（分别为 2J/cm²和 0.6J/cm²）。
使用热成像相机确定皮肤温度升高的峰值和最大值。采用配对样本 t 检验比较峰值温度升高的平均值。通过数字显微镜评估消融凹坑。结果：Er:YAG 激光和 PIRL 的皮肤表面温度峰值平均升高分别为 15.0°C 和 1.68°C（P<0.001）。皮肤表面温度的最大峰值升高分别为 18.85°C 和 2.05°C。在数字显微镜上确认了消融凹坑。
皮秒红外激光消融产生的热量可忽略不计，远低于 Er:YAG 激光消融，这证实了这项新技术在最小化与临床使用的激光相关的不良热损伤方面的潜力。
