LaMuraglia G M, Murray S, Anderson R R, Prince M R
Vascular Service, Massachusetts General Hospital, Harvard Medical School, Boston 02114.
Lasers Surg Med. 1988;8(1):18-21. doi: 10.1002/lsm.1900080106.
The effect of varying pulse duration on selective ablation of human arterial plaque was evaluated by measuring ablation thresholds and ablation efficiencies on fresh human fibrofatty plaque, calcified plaque, normal intima, deep media, and adventitia using 480- to 490-nm laser radiation at 1, 8, and 50-microseconds pulse durations. For all tissues examined, the ablation threshold energy increased with increasing pulse duration, but the threshold for normal tissue ablation was approximately twice that of plaque at all pulse durations. Ablation efficiency was studied at a fluence that was twice the ablation threshold for plaque. For those fluences, normal intima had detectable ablation only at 50 microseconds. The ablation efficiency of fibrofatty plaque was minimally reduced with prolongation of pulse duration; however, there was a substantial decrease in the ablation efficiency of calcified plaque when the pulse duration was lengthened from 8 to 50 microseconds. These data show significant selective ablation of fibrofatty and calcified plaque at 1, 8, and 50 microseconds and suggest that the optimal pulse width for selective ablation of all plaque in the 480- to 490-waveband is less than 50 microseconds.
通过在1微秒、8微秒和50微秒的脉冲持续时间下，使用480至490纳米的激光辐射，测量新鲜人纤维脂肪斑块、钙化斑块、正常内膜、深层中膜和外膜的消融阈值和消融效率，评估不同脉冲持续时间对人动脉斑块选择性消融的影响。对于所有检查的组织，消融阈值能量随脉冲持续时间的增加而增加，但在所有脉冲持续时间下，正常组织消融的阈值约为斑块的两倍。在斑块消融阈值两倍的能量密度下研究消融效率。对于这些能量密度，正常内膜仅在50微秒时有可检测到的消融。纤维脂肪斑块的消融效率随脉冲持续时间的延长而最小程度降低；然而，当脉冲持续时间从8微秒延长到50微秒时，钙化斑块的消融效率大幅下降。这些数据表明在1微秒、8微秒和50微秒时对纤维脂肪和钙化斑块有显著的选择性消融，并表明在480至490波段对所有斑块进行选择性消融的最佳脉冲宽度小于50微秒。
