Effects of cryogen spray cooling and high radiant exposures on selective vascular injury during laser irradiation of human skin.
Effects of cryogen spray cooling and high radiant exposures on selective vascular injury during laser irradiation of human skin.
复制标题
DOI：
10.1001/archderm.139.6.743
复制
发表时间：
2003-06
影响因子：
--
通讯作者：
J. Tunnell;D. Chang;C. Johnston;J. Torres;C. Patrick;Michael J. Miller;S. Thomsen;B. Anvari
中科院分区：
文献类型：
--
作者：
J. Tunnell;D. Chang;C. Johnston;J. Torres;C. Patrick;Michael J. Miller;S. Thomsen;B. Anvari
背景：在激光介导的血管病变（如葡萄酒斑）治疗中，增加辐射暴露提供了一种提高治疗效果的手段；然而，过度的辐射暴露减少了选择性血管损伤，这是由于表皮内热量的增加和血管周围胶原蛋白的附带损伤。目的探讨在高辐射照射（16-30 J/cm2）下，低温喷雾冷却是否可用于维持选择性血管损伤（即防止表皮和血管周围胶原损伤）。设计观察性研究。学术医院和研究实验室。20例女性，腹部皮肤正常（皮肤光型I-VI）。皮肤用脉冲染料激光（波长= 585 nm；脉冲持续时间= 1.5毫秒；5毫米直径光斑）照射，使用不同的辐射暴露（8-30 J/cm2），不使用和使用冷冻剂喷雾冷却（50- 300毫秒的冷冻剂喷射）。每个照射部位的苏木精-伊红染色组织学切片检查表皮损伤程度、红细胞凝固最大深度和含有血管周围胶原凝固的血管百分比。结果在最高辐射暴露（30 J/cm2）条件下，长时间低温喷射对浅肤色个体（皮肤光型I-IV型）的表皮有保护作用；然而，即使在最低的辐射暴露（8 J/cm2）下，深色皮肤个体（皮肤光型V-VI）的表皮保护也无法实现。随着辐射暴露的增加，红细胞凝固深度增加（皮肤光型I-IV约2.5 mm，皮肤光型V-VI约1.2 mm）。此外，在所有皮肤类型中，长时间的低温喷射持续时间（约200毫秒）可阻止血管周围胶原蛋白凝固。结论：在皮肤激光治疗过程中，当使用高辐射暴露时，比目前治疗中使用的低温喷射持续时间长得多（约200毫秒），可能在临床上对保护表皮和血管周围组织有用。需要进一步的研究来证明这些方案的临床安全性。
BACKGROUND Increasing radiant exposure offers a means to increase treatment efficacy during laser-mediated treatment of vascular lesions, such as port-wine stains; however, excessive radiant exposure decreases selective vascular injury due to increased heat generation within the epidermis and collateral damage to perivascular collagen. OBJECTIVE To determine if cryogen spray cooling could be used to maintain selective vascular injury (ie, prevent epidermal and perivascular collagen damage) when using high radiant exposures (16-30 J/cm2). DESIGN Observational study. SETTING Academic hospital and research laboratory. PATIENTS Twenty women with normal abdominal skin (skin phototypes I-VI). INTERVENTIONS Skin was irradiated with a pulsed dye laser (wavelength = 585 nm; pulse duration = 1.5 milliseconds; 5-mm-diameter spot) using various radiant exposures (8-30 J/cm2) without and with cryogen spray cooling (50- to 300-millisecond cryogen spurts). MAIN OUTCOME MEASURE Hematoxylin-eosin-stained histologic sections from each irradiated site were examined for the degree of epidermal damage, maximum depth of red blood cell coagulation, and percentage of vessels containing perivascular collagen coagulation. RESULTS Long cryogen spurt durations (>200 milliseconds) protected the epidermis in light-skinned individuals (skin phototypes I-IV) at the highest radiant exposure (30 J/cm2); however, epidermal protection could not be achieved in dark-skinned individuals (skin phototypes V-VI) even at the lowest radiant exposure (8 J/cm2). The red blood cell coagulation depth increased with increasing radiant exposure (to >2.5 mm for skin phototypes I-IV and to approximately 1.2 mm for skin phototypes V-VI). In addition, long cryogen spurt durations (>200 milliseconds) prevented perivascular collagen coagulation in all skin types. CONCLUSIONS Cryogen spurt durations much longer than those currently used in therapy (>200 milliseconds) may be clinically useful for protecting the epidermis and perivascular tissues when using high radiant exposures during cutaneous laser therapies. Additional studies are necessary to prove clinical safety of these protocols.