Hohenleutner U, Hilbert M, Wlotzke U, Landthaler M
Department of Dermatology, University of Regensburg, Germany.
J Invest Dermatol. 1995 May;104(5):798-802. doi: 10.1111/1523-1747.ep12606996.
To investigate vessel coagulation depth and tissue damage in therapy with the flashlamp-pumped pulsed dye laser (585 nm, 5 mm spot size, 450 microsecond pulse duration, 6-8 J/cm2), we used the nitroblue-tetrazolium chloride stain in 22 post-treatment biopsy specimens from patients with port wine stain. With this method, thermally damaged tissue can be easily differentiated from unchanged tissue to the level of single cells. The results showed that in superficial port wine stain vessels up to 150 microns in diameter, vessel coagulation was complete and selective without further dermal damage. With the increase of vessel diameter, strong superficial hemoglobin absorption led to only partial vessel-wall coagulation and, in some cases, to superficial dermal damage. Likewise, deeper vessels were not coagulated because of shadow effects by superficial vessel layers. Thus, the overall vessel-wall coagulation depth of the flashlamp-pumped dye laser was limited to a maximum of 0.65 mm (mean 0.37 mm). In addition, some degree of epidermal damage was present in most specimens, which significantly increased with epidermal melanin content and resulted in epidermal coagulation and blistering in pigmented skin. Our results explain the occurrence of crusting, hyperpigmentation, and hypopigmentation in therapy with the flashlamp-pumped dye laser and its limited effect on dark or hypertrophic port wine stains in adults featuring large vessel diameters or multiple vessel layers.
为了研究闪光灯泵浦脉冲染料激光（585纳米，光斑尺寸5毫米，脉冲持续时间450微秒，能量密度6 - 8焦耳/平方厘米）治疗时的血管凝固深度和组织损伤情况，我们对22例患有葡萄酒色斑患者的治疗后活检标本使用了氯化硝基四氮唑蓝染色法。通过这种方法，热损伤组织能够很容易地与未改变的组织区分开来，直至单细胞水平。结果显示，对于直径达150微米的浅表葡萄酒色斑血管，血管凝固是完全且具有选择性的，不会造成进一步的真皮损伤。随着血管直径增大，强烈的浅表血红蛋白吸收导致仅部分血管壁凝固，在某些情况下还会造成浅表真皮损伤。同样，由于浅表血管层的阴影效应，更深层的血管未被凝固。因此，闪光灯泵浦染料激光的整体血管壁凝固深度最大限制为0.65毫米（平均0.37毫米）。此外，大多数标本中存在一定程度的表皮损伤，这种损伤会随着表皮黑色素含量显著增加，导致色素沉着皮肤出现表皮凝固和水疱。我们的结果解释了闪光灯泵浦染料激光治疗中结痂、色素沉着过度和色素沉着不足的发生情况，以及其对具有大血管直径或多层血管的成人深色或肥厚性葡萄酒色斑疗效有限的原因。
