Cardiovascular Laser Application

With the invention of the laser, many clinical disciplines have taken advantage of this new energy source. Its precision, intensity and energy density is superior to all other known surgical devices. Based on the principle of light amplification from a photon-emitting resonator, the monochromaticity, collimation and coherence provide the high-energy density of the laser beam for medical applications. The state-of-the-art and future potential of laser use in cardiovascular diseases will be reviewed. Most of the work in this field has been accomplished during the past decade with numerous research projects. Although many technical advances have been made, so far the results in cardiovascular medicine are in the areas of vessel anastomosis, ablation of conduction passes for arrhythmia therapy, and angioplasty. In this paper, special attention will be given to the recent success in XeCl excimer laser application for photodecomposition of tissue with a goal of improved recanalization. The high-power density of the XeCl excimer laser provides significant advantages for the disruption of both embolic and calcified plaque. Regardless of the type of tissue ablated, gross, histologic, and ultra-structural analysis confirmed the absence of thermal injury in luminar recanalization as well as in animal studies. Progress in the manufacture of catheters, with multiple very small diameter fibers, led to the decisive breakthrough in clinical laser angioplasty. Peripheral as well as coronary arteries have been successfully recanalized followed by balloon dilatation. The ease of application and the success achieved thus far have resulted in an optimistic assessment for laser medicine.     

Measurement of laser-beam profile by using a video camera

Laser-beam profile is an important laser parameter that is frequently ignored because conventional measurement techniques are cumbersome. A technique for accurately and rapidly measuring laser-beam profile with a commercial video camera and oscilloscope is described. Both two-dimensional pictures of the beam and quantitative, one-dimensional beam profiles can be obtained. The technique is particularly well suited for biomedical applications because it is compatible with most pulsed and continuous wave visible lasers, it uses readily available and relatively inexpensive components, and it is easy to implement.     

激光脱毛的临床效果观察

目的　观察激光脱毛的临床效果。方法　应用新型固体二极管激光脱毛机进行治疗，术中从低能量开始，至毛囊焦化破坏为止。术后局部涂少量抗生素软膏，无需包扎。结果　１３４例脱毛者均取得了理想的效果，一般２～６个月可有部分毛发再生，但毛发细小、色淡，需补治１～２次即可完全达到脱毛的目的。结论　新型固体二极管激光脱毛效果可靠，操作简单，速度快，无损伤、色素沉着及瘢痕等并发症，是目前临床上最好的一种脱毛方法。     

MEDLITE四波长激光脱毛疗效观察

目的：观察激光脱毛的临床效果。方法：应用Ｑ开关Ｎｄ：ＹＡＧ固体四波长激光对８６例多毛患者进行治疗,波长选择１０６４ｎｍ,光斑选择８ｍｍ或６ｍｍ,对应的能量为２．２Ｊ／ｃｍ ＾２或３．８Ｊ／ｃｍ ＾２。每位脱毛者每３周～８周脱毛一次。结果：８６例患者分别在脱毛３～６次后远达到理想的脱毛效果。结论：ＭＥＤＬＩＴＥ四波长激光脱毛效果可靠,无明显并发症,是目前较好的一种脱毛方法。     

YAG激光祛除各种不良文饰的应用

目的 观察ＹＡＧ激光祛除各种不良文饰的治疗效果。方法 选择ＹＡＧ激光系统，根据文饰的颜色，选择１０６４ｎｍ波长、７５５ｎｍ波长及５３２ｎｍ波长进行治疗，每次治疗间隔２～３个月。结果 痊愈６５２例，显效８例，有效率达１００％，文眉一般需１～２次，其他文饰需２～４次治疗。结论 ＹＡＧ激光祛队各种不良文饰安全可靠，疗效确切，不留疤痕。     

Q开关激光去除皮肤细胞色素机理探讨

目的探讨新型Ｑ开关激光去除皮肤细胞色素的机理。方法用３种不同的Ｑ开关激光作用于猪及豚鼠的有色皮肤区,观察其结果。结果Ｑ开关激光治疗后皮肤色素即被气化或碎裂,色素病变消失,色素细胞呈空泡状,但色素细胞轮廓的框架仍可完整保留,色素细胞周围组织并未受损伤,仍可存活。结论Ｑ开关激光只破坏色素颗粒或色素细胞,而邻近的正常细胞不被破坏,是目前治疗皮肤色素性疾病较有效、副作用较小的方法。     

The Effects of Laser Light on Sperm Motility and Velocity in vitro

The effect of Laser light on the motility and the velocity of human spermatozoa were measured by means of multiple exposure photography. Total sperm motility increased after Laser irradiation at 4 J/cm2, 8 J/cm2 and 32 J/cm2 respectively with respect to control. However, no influence on sperm velocity was demonstrated after Laser irradiation. This observation suggests that Laser light stimulates non-motile live spermatozoa.     

Studies of Er-YAG laser interactions with soft tissue

The ablation efficiency and depth of secondary thermal damage have been determined for a range of cadaveric soft tissues on exposure to radiation from a pulsed Er-YAG laser operating at 2.94m. The tissues investigated included brain, small intestine, stomach, liver, heart, spleen, lung, aorta, cornea, kidney, skin and uterus. The results obtained are compared to those predicted by a simple one-dimensional model of the interaction. The amount of tissue damage varied between tissues. In cellular tissues it was approximately 20m in extent on either side of the slot and at its base. In acellular tissues (aorta, cornea, etc.) the alteration in protein structure was more variable and was dependent upon the nature of the connective tissue fibres. Corneal collagen showed changes in protein structure up to 30m from the edge of the slot, whereas aortic elastic fibres were little affected by the laser energy, apparently melting to form a coagulum that lined the slot.     

Qualitative und quantitative Auswirkungen der Neodym-YAG-Laserstrahlung auf Schweineaorten unter dem Gesichtspunkt der Angioplastik

Zusammenfassung In den letzten Jahren eröffnete die Anwendung des Lasers eine weitere Möglichkeit zur Entfernung von atheromatösen Plaques und thrombotischen Verschlüssen. Experimentelle Untersuchungen belegen, daß diese Methode ein neues und möglicherweise wertvolles Verfahren bei der Behandlung obstruktiver Gefäßerkrankungen darstellt. Wir verwendeten einen 1060 nm Nd-YAG-Dauerstrichlaser mit fokussiertem optischen Leitsystem. Segmente von Schweineaorten wurden in Längsrichtung eröffnet und dem Laserstrahl exponiert. Es fanden sich vier grundsätzliche Reaktionsmuster: lokale Schwellung, Aufbrechung der intimanahen Wandschichten, verkohlter kraterförmiger Substanzdefekt und Wandperforation. Die histologische Untersuchung ergab ein charakteristisches Schädigungsmuster als Folge der thermischen Einwirkung. Die Gewebsvaporisation stellt bei der Laserangioplastik den gewünschten Effekt dar. Die thermischen Veränderungen limitieren die Anwendungsmöglichkeit des Nd-YAG-Dauerstrichlasers bei dieser Zielsetzung.

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Qualitative and quantitative effects of Nd-YAG laser irradiation on porcine aortic vessels concerning angioplastic procedures

Summary During last few years the concept of vaporizing atheromatous plaques and thrombotic occlusions by laser energy arose. This method is a new and possibly valuable modality in the treatment of obstructive vascular diseases. We used a continuous 1,060 nm Nd-YAG laser with a focused optical wave guide. Sections of porcine aortic vessels were split longitudinally and exposed to laser radiation. Four major types of tissue alterations were observed: local swelling, disruption of the inner layers of the vessel wall, charred punched-out defects and wall perforation. Histologic examination revealed a typical damage pattern as a result of thermic injury. Clean tissue alteration is the desired effect for angioplasty. The thermic alterations limit the applicability when dealing with the cw Nd-YAG laser for this purpose.

     

Q—开关翠绿宝石激光治疗雀斑及雀斑样痣

目的;观察翠绿宝石激光治疗雀斑及雀斑样痣的疗效及并发症。方法：用Q－开关翠绿宝石激光不同剂量治疗不同部位雀斑及雀斑样痣。结果：共治疗125例,有效率100％。结论：Q－开关翠绿宝石激光治疗雀斑及雀斑样痣疗效良好,皮肤不留疤痕。     

倍频Nd:YAG激光治疗酒渣鼻疗效观察

目的：研究激光治疗酒渣鼻的临床疗效。和倍频Ｎｄ：ＹＡＧ（ＶＰＷ５３２ｎｍ）激光治疗酒渣鼻,结果：此方法治疗酒渣鼻治愈率８０％。结论：倍频Ｎｄ：ＹＡＧ（ＶＰＷ５３２ｎｍ）激光是治疗酒渣鼻的有效方法之一。     

激光脱毛380例临床分析

目的 探讨激光脱毛的效果，并总结380例激光脱毛经验。方法 采用800nm波长、脉宽30ms的半导体激光脱毛机，根据不同部位，选择不同能量及不同时间间隔。发际选择最低能量19J／cm^2，间隔3～4周后，再做下一次治疗，每次需增加1～2J／cm^2，经过3～5次治疗，最高能量达到25J／cm^2。小腿选择最低能量36J／cm^2，间隔7周左右再做下一次治疗，每次需增加2～3J／cm^2。每次治疗后，均无需特殊处理。结果 观察1／2～1年95％效果良好。20例治疗后出现过几个或多个斑点状色素沉着，有6例2个月后消失，即在第2次治疗时消失，有8例3个月消失，即第3次治疗时消失，还有4例是4个月后消失，仅有2例肤色较深者(含黑素较多的人)，在治疗后观察1年时，仍有少量色素沉着。结论 激光治疗后初期毛发的再生延迟，新生毛发质地由粗变细，颜色由深变浅，需经多次治疗。根据毛发部位的不同，选定不同的能量，才能最终达到永久性脱毛的目的。     

Laser systems for cardiovascular applications

Different laser systems have been proposed for angioplasty. A brief overview is given in order to describe the basic concepts which characterize each case. The results of a comparison are presented.     

点阵模式激光在瘢痕治疗中的临床应用

目的 评价两种剥脱性点阵模式激光治疗浅表瘢痕的安全性及有效性.方法 共88例患者,其中痤疮瘢痕66例,烧伤瘢痕12例,其他瘢痕10例.所有患者均经以下任何一种治疗:像柬激光≥3次;或点阵激光≥2次;或像束激光+点阵激光综合治疗≥3次.治疗过程中视病情需要配合应用脉冲染料激光抑制瘢痕增生,减轻红斑.结果 本组共88例,瘢痕改善程度评价标准:改善程度>25%视为有效,>50%视为显效,本组患者显效率50%(44/88),有效治疗达80%(70/88).像束激光治疗共244人次,点阵激光治疗共86人次,色素沉着共7例,均在半年内消退,无其他严重并发症.结论 点阵模式的激光治疗创伤小,风险低,是治疗浅表瘢痕,尤其是痤疮瘢痕的有效手段,其作用的机制包括组织气化、磨削作用及热损伤带来的促进组织修复的强大动力.     

激光吸脂术的动物实验研究

目的　评价激光吸脂术相对于常规吸脂术的优缺点。方法　将实验动物分为激光吸脂术、常规吸脂术和对照组 3组。对两手术组动物以术后皮肤有否瘀斑、水肿及抽吸物的脂 血容量比值、术前术后血红蛋白含量和血生化指标改变进行比较。结果　激光吸脂术在术后皮肤瘀斑、水肿、抽吸物脂 血比值和更少并发症方面优于常规吸脂术。且术后皮肤瘀斑和抽吸物的脂 血比值差异有显著性意义 (P <0 0 5 ) ;两组术前及术后血红蛋白含量变化差异无显著性意义 ;激光吸脂术对动物肝肾功能无影响。结论　激光吸脂术术中出血、术后皮肤瘀斑和水肿等比常规吸脂术明显减少 ,并不会导致实验动物肝肾功能损害。     

Laser assisted vessel anastomosis of coronary arteries in vitro: Optimization of bonding conditions

Laser-assisted anastomosis of pigs' coronary arteries has been investigated using an Argon laser and a technique of applying an appropriate chromophore to the site of anastomosis. Remote infrared temperature measurements have shown that bonding was achieved at temperatures between 65 and 80°C corresponding to the collagen denaturation temperature and visual changes in the appearance of the tissue. Further laser irradiation produced carbonization and extensive tissue damage. Application of a chromophore at the site of anastomosis allowed a large reduction in the incident laser energy density. In end-to-end anastomosis, with only one supportive stay suture, bursting pressures of 90 to 310 mmHg (mean 203 mmHg) were achieved within a power range of 0.3 to 0.5 W with an exposure time of 50 to 210 s. Histological sections showed limited tissue damage but some variation in the vessel wall alignment which may explain variability in the mechanical strength. The laboratory studies have allowed us to optimize bonding conditions before embarking on animal tests.     

Q开关Nd:YAG激光治疗不良眼线疗效评价

目的：评价Ｑ开关Ｎｄ：ＹＡＧ激光对不理想眼线文饰的疗效。方法：以质量分数描述疗前疗后不理想眼线文饰的表现，以积分下降比率确定疗效。结果：８２例求治者治疗前总积分（３６７分）与治疗一次后总积分（２０８分）８２例最后痊愈：２３例，显效：５１例，无效：８例。经统计学处理，差异有显著性意义（ｔ＝３．６５ Ｐ〈０．００１）。激光能量大小的选择、接受治疗次数与眼线的颜色有关。结论：Ｑ开关Ｎｄ：ＹＡＧ激光对去除     

经尿道激光烧灼术治疗腺性膀胱炎(附九例报告)

为探索治疗腺性膀胱炎的方法，采用经尿道激光烧灼术治疗经病理活检证实的腺性膀胱炎９例，随访６～２０个月，６例治愈，２例好转，无效１例。讨论了腺性膀胱炎的病因及病理，并重点介绍了激光烧灼术操作的注意事项及随诊情况。认为经尿道激光烧灼术是治疗腺性膀胱炎的一种行之有效的方法。     

Comparative evaluation of the effects of Nd:YAG and Er:YAG laser in dentin hypersensitivity treatment

Dentin hypersensitivity (DH) is one of the most common complications that affect patients after periodontal therapy. So far, many investigators have successfully used different types of laser on DH treatment. The aim of this study was to evaluate the comparative effect of Nd:YAG laser and Er:YAG laser on human teeth desensitization. A group of nine patients with a total of 63 chronic hypersensitive teeth were selected. Each one of them should at least have three hypersensitive teeth. These teeth were randomly allocated into three groups. Group 1, Nd:YAG laser (1 W, 15 Hz, 60 s, two times); group 2, Er:YAG laser (100 mJ, 3 Hz, 60 s, two times); and group 3 serves as control group without any treatment. Assessment of pain was performed by a visual analysing scale (VAS) after stimulation of sensitive tooth by using the sharp tip of an explorer. This test was performed before treatment, immediately after that and at 1-, 3- and 6-month intervals after treatment by one blinded examiner. Analysis of VAS score between the three groups at the time of treatment did not show any significant difference (p = 0.506). However, by using repeated-measurement analysis of variance test, significant differences were seen in the three groups between before-treatment VAS score and after treatment (p < 0.0005). This statistically significant difference in the control group demonstrated a placebo effect. However, the effect of using Nd:YAG and Er:YAG lasers was stronger than this placebo effect, so that after removing the effect of the placebo, differences immediately after, 1, 3 and 6 months post treatment between all three groups still were statistically highly significant (p < 0.0005). Compared to the Er:YAG laser group, using Nd:YAG laser resulted in a significant reduction of VAS score at each follow-up examination (p < 0.0005). Although using Nd:YAG and Er:YAG laser in desensitization of hypersensitive teeth showed a placebo effect limited to a short time, results of this study demonstrated that both of these lasers have an acceptable therapeutic effect. The observed effects seemed to last for at least 6 months. It was concluded that Nd:YAG laser is more effective than Er:YAG laser in reduction of patients’ pain.