Bowes Leyda Elizabeth, Nouri Keyvan, Berman Brian, Jimenez Gloria, Pardo Rube, Rodriguez Lucila, Spencer James M
Department of Dermatology and Cutaneous Surgery, University of Miami School of Medicine, Miami, Florida, USA.
Dermatol Surg. 2002 Aug;28(8):714-9. doi: 10.1046/j.1524-4725.2002.01058.x.
Pigmented hypertrophic scars are a difficult condition to treat. They may result from traumatic injuries or from surgical and cosmetic procedures. The 585 nm flashlamp-pumped pulsed dye laser (FLPDL) has been used to treat this condition, with significant improvement of varying degrees. It remains to be determined whether other laser modalities may have a similar or even greater success in the treatment of pigmented hypertrophic scars.
To determine the efficacy of the 532 nm frequency-doubled Nd:YAG laser in the treatment of pigmented hypertrophic scars as compared to the 585 nm FLPDL.
Six patients with pigmented hypertrophic scars and skin phototypes II-IV were chosen. A scar was selected for treatment in each patient and divided into four equal 2 cm segments. Three segments were each treated with a different laser modality and one was left untreated to serve as the control. A 585 nm FLPDL was used with an energy of 3.5 J, a pulse duration of 450 microsec, and a 10 mm spot size. A 532 nm Q-switched frequency-doubled Nd:YAG laser was set to an energy of 2.8 J, a 10-nsec pulse, and a 3 mm spot size. The same 532 nm laser was set to the variable pulse mode to treat a 2 cm scar segment, with an energy of 9.5 J, a 10-msec pulse, and a 4 mm spot size. An average of 3.3 treatments were performed on each scar segment, at intervals of 4-6 weeks and long-term follow-up at 22 weeks. Treatment outcome was graded by a blind observer using the Vancouver General Hospital (VGH) Burn Scar Assessment Scale. A SigmaStat t-test was used to determine the statistical significance of the values obtained.
Treatment of pigmented hypertrophic scars with the 532 nm Q-switched Nd:YAG laser led to a significant improvement of 38% in the VGH scores when compared to baseline (P =.005). The 585 nm FLPDL also had a favorable effect on the scars, with an average improvement of 36.1% in the VGH scores. There was no significant difference noted between the outcome of treatment with either of these two lasers. Treatment with the 532 nm variable pulse Nd:YAG laser led to a 19% improvement in the VGH scores of scars, which did not differ significantly from the 16.1% improvement observed in control scars on the last follow-up visit. No side effects or complications from treatment were noted or reported during the course of the study. At the conclusion of the study, five of six patients chose the segment treated with the 532 nm Q-switched Nd:YAG laser as the best segment overall.
The 532 nm Q-switched Nd:YAG laser and the 585 nm FLPDL offer comparable favorable results in the treatment of pigmented hypertrophic scars. The 532 nm Q-switched Nd:YAG laser may be preferred by patients particularly distressed by the dark color of their scars.
色素沉着性增生性瘢痕是一种难以治疗的病症。它们可能由创伤性损伤或手术及美容手术引起。585纳米闪光灯泵浦脉冲染料激光（FLPDL）已被用于治疗这种病症，并取得了不同程度的显著改善。其他激光模式在治疗色素沉着性增生性瘢痕方面是否可能取得类似甚至更大的成功仍有待确定。
与585纳米FLPDL相比，确定532纳米倍频Nd:YAG激光治疗色素沉着性增生性瘢痕的疗效。
选择6例皮肤光型为II - IV型的色素沉着性增生性瘢痕患者。为每位患者选择一个瘢痕进行治疗，并将其分成四个2厘米长的相等部分。三个部分分别用不同的激光模式进行治疗，一个部分不治疗作为对照。使用能量为3.5焦耳、脉冲持续时间为450微秒、光斑尺寸为10毫米的585纳米FLPDL。将532纳米调Q倍频Nd:YAG激光设置为能量2.8焦耳、脉冲10纳秒、光斑尺寸3毫米。使用同一台532纳米激光设置为可变脉冲模式治疗一个2厘米长的瘢痕部分，能量为9.5焦耳、脉冲10毫秒、光斑尺寸4毫米。每个瘢痕部分平均进行3.3次治疗，间隔4 - 6周，并在22周进行长期随访。由一名盲法观察者使用温哥华总医院（VGH）烧伤瘢痕评估量表对治疗结果进行分级。使用SigmaStat t检验确定所获数值的统计学意义。
与基线相比，用532纳米调Q Nd:YAG激光治疗色素沉着性增生性瘢痕使VGH评分显著改善38%（P = 0.005）。585纳米FLPDL对瘢痕也有良好效果。VGH评分平均改善36.1%。这两种激光治疗的结果之间未发现显著差异。用532纳米可变脉冲Nd:YAG激光治疗使瘢痕的VGH评分提高了19%，这与最后一次随访时对照瘢痕观察到的16.1%的改善无显著差异。在研究过程中未观察到或报告治疗的副作用或并发症。在研究结束时，六名患者中有五名选择用532纳米调Q Nd:YAG激光治疗的部分作为总体上最好的部分。
532纳米调Q Nd:YAG激光和585纳米FLPDL在治疗色素沉着性增生性瘢痕方面提供了相当的良好效果。对于因瘢痕颜色深而特别苦恼的患者，532纳米调Q Nd:YAG激光可能更受青睐。
