低能量半导体激光椎间盘修复术在成年猪离体脊柱中的热扩散特性

Thermal diffusion of low-energy semiconductor laser disc repair in adult porcine spine

中文关键词:  低能量半导体激光  热辐射效应  动物实验  光热效应  腰椎退变

英文关键词:Low-energy semiconductor laser  Thermal radiation effects  Animal experiments  Photothermal  Disc degeneration

中文摘要:

  【摘要】 目的：观察低能量半导体激光椎间盘修复术（low-energy semiconductor laser disc repair，LESL-DR）中激光作用于椎间盘过程中椎间盘内部及周围组织的热扩散规律和局部组织学变化。方法：选取3只体重约40kg成年长白猪，采集L1~L5节段完整离体椎体-椎间盘结构单元，选取其中9例完整椎体-椎间盘单元样本随机均分为低功率组（n=3）、中功率组（n=3）和高功率组（n=3），分别采用1W、2W和3W功率的低能量半导体激光对椎间盘中心点连续照射5min。照射过程中，利用高精度红外热成像系统实时监测椎间盘中心（P1）、纤维环中点（P2）及椎管前壁（P3）的温度变化。照射结束后，对椎间盘组织进行苏木精-伊红（HE）染色，观察组织学改变。结果：连续照射5min后，P1点温度在三种功率组中无统计学差异（P=0.064），P2温度在低、中、高功率组分别为（50.62±2.44）℃、（65.51±2.46）℃、（68.12±3.3）℃，差异具有统计学意义（P＜0.01），P3温度分别为（32.3±2.51）℃、（42.77±2.17）℃和（48.93±3.03）℃，差异具有统计学意义（P＜0.01）。激光照射过程中，P1、P2及P3三个测温点温度均随时间升高。P1在照射初期（0~40s）迅速升温，随后进入平台期，并于210~240s期间出现“二次升温”现象，各组峰值温度均超过100℃，其中高功率组超过110℃；P2温度变化趋势与P1相似，但低功率组升温幅度较小；P3温度受激光功率影响最为显著，高功率组最高接近50℃，中功率组约40℃，而低功率组始终低于35℃。组织学观察发现，激光照射后椎间盘组织损伤程度随功率升高而增加，表现为碳化范围扩大及纤维环基质结构破坏逐渐加重。结论：低能量半导体激光在离体猪椎间盘中的热扩散呈现“快速升温-平台期-二次升温”的三阶段特征，随着激光功率增加，椎间盘不同测温点处峰值温度及组织损伤程度也随之升高。

英文摘要:

  【Abstract】 Objectives: To observe the dynamic thermal diffusion patterns and local histological changes in disc and surrounding area during low-energy semiconductor laser disc repair(LESL-DR). Methods: Three adult pigs weighing approximately 40kg were used in this study. Intact vertebra-intervertebral disc structure units from L1 to L5 in vitro were collected and nine intact intervertebral disc samples were selected and randomly divided into three groups of a low-power group(n=3), a medium-power group(n=3), and a high-power group(n=3), which were continuously irradiated for 5min using a low-energy semiconductor laser at power settings of 1W, 2W, and 3W, respectively. During irradiation, real-time temperature changes were monitored using a high-precision infrared thermographic imaging system at three predefined sites: the disc center(P1), the center of the annulus fibrosus(P2), and the anterior wall of the spinal canal(P3). Histological changes were assessed using hematoxylin and eosin staining after irradiation. Results: After 5 minutes of continuous irradiation, the temperature at point P1 did not reach statistical significance(P=0.064); At point P2, the temperatures were (50.62±2.44)℃, (65.51±2.46)℃, and (68.12±3.30)℃ in the low-, medium-, and high-power groups(P<0.01); Similarly, at point P3, the temperatures were (32.30±2.51)℃, (42.77±2.17)℃, and (48.93±3.03)℃(P<0.01). During laser irradiation, temperatures at P1, P2 and P3 increased over time. The temperature at P1 exhibited a rapid increase during the initial phase(0-40s), followed by a plateau and a secondary rise between 210s and 240s. Peak temperatures at P1 exceeded 100℃ in all groups and surpassed 110℃ in the high-power group. The temperature pattern at P2 was similar to that observed at P1, although the magnitude of increase was lower in the low-power group. Temperature changes at P3 were most strongly dependent on laser power, with maximal temperatures approaching 50℃ in the high-power group, approximately 40℃ in the medium-power group, and consistently remaining below 35℃ in the low-power group. Histological analysis revealed a clear power-dependent increase in intervertebral disc tissue damage after laser irradiation, characterized by progressive expansion of carbonized areas and increasing disruption of the annulus fibrosus matrix architecture.Conclusions: LESL-DR produces a three-stage characteristic of "rapid temperature rise - plateau period - secondary temperature rise" thermal diffusion patterns in ex vivo porcine intervertebral discs. As laser power increases, the peak temperature and degree of tissue damage at different temperature measurement points of the intervertebral disc also increase.