In vitro quantitative study of fibre optic XeCI laser angioplasty. Influence of lasing medium and adventitial resistance to photoablation

In this paper, we present a comparative study of atheromatous human plaque photoablation at 308 nm in air, saline or blood, with the tip of the laser energy delivering fibre in close contact with the sample. The ablation depth, measured on histological sections, is given as a function of the number of shots at different laser fluences. The photoablation efficiency depends mostly on the pathological state of the artery rather than on the irradiation medium A clear resistance of the adventitia to 308 nm photoablation is demonstrated in all media. This finding may be an important safety factor for XeCl human coronary angioplasty.     

Percutaneous recanalization of arteries: Status and prospects of laser angioplasty with modified fibre tips

Percutaneous balloon dilatation of arterial stenoses is a firmly established non-surgical treatment of ischaemic disease. The number of percutaneous transluminal coronary angioplasties performed per year in the USA approaches the number of coronary artery bypass graft operations. A great number of novel percutaneous recanalization schemes address the major problems of balloon angioplasty: failure to cross the stenosis (occlusion), failure to dilate effectively (15–20%), acute complications (5%) and re-stenosis within six months (30–40%). Laser energy can effectively evaporate atheromatous plaque, but delivery by an unmodified bare fibre creates only a small channel and carries a high risk of vessel-wall perforation in the coronary arteries. It appears impossible to maintain an axial position in small, tortuous and moving arteries with multiple side-branches. Coronary lesions are anatomically and structurally heterogeneous. Reduction of the perforation risk is being approached by four strategies: (a) optimization of the power source; (b) enhancement of laser-light absorption by plaque relative to artery wall; (c) improvement of plaque recognition; and (d) modification of the delivery system, which is discussed in detail. Recanalization of occluded femoropopliteal arteries with the 2.0-mm metal laser probe has proved to be safe and effective in more than 100 patients. The 2.2-mm rounded sapphire contact probe has been used with success in the peripheral arteries of over 30 patients. The recanalization mechanism of both probes is not yet fully understood. Closed-chest attempts at recanalization of coronary arteries by the 1.7-mm metal laser probe have been reported in 13 patients, with success in the majority. There were no complications requiring emergency surgery. The possible occurrence of embolism or spasm in three cases warrants a cautious approach to application of the metal laser probe in the coronary catheterization room. The primary benefit of laser recanalization with modified fibre tips is the possible transformation of a candidate for surgery into a candidate for balloon angioplasty. It remains to be established whether prior laser debulking of the atheroma will reduce the incidence of acute complications of balloon dilatation and will reduce restenosis in the subsequent year. In the past two years an avalanche of laser and non-laser recanalization schemes have been developed. In peripheral arteries, early results of most methods have shown an acceptably low incidence of acute perforations or other complications. The human arterial wall can take a heavy beating, both mechanically and thermally. In the next decade, catheter intervention techniques will progressively contribute to the treatment of peripheral and coronary artery disease.     

调Q开关紫翠宝石激光治疗太田痣的疗效

目的探讨调Q开关紫翠宝石激光治疗太田痣的临床疗效。方法采用波长752nm的调Q—Alexandrite激光PhotoGenica HT10治疗1985例太田痣患者,并从年龄、治疗次数、间隔时间及不良反应等方面进行分析,比较疗效。结果1985例太田痣患者中显效率97．88％,总有效率100％;各年龄组均有良好效果,组间差异无统计学意义（P〉0．05）;多数患者（55．2％）需经4～5次治疗即可获较好疗效,极少数（0．8％）患者,需要治疗10次以上;治疗1～3次及6～10次达到较好效果的分别占18．2％和25．8％;2次治疗时间间隔4～6个月组与治疗间隔6个月组显效率高于不足3个月组,但治疗间隔4～6个月组与治疗间隔6个月组差异无统计学意义（P〉0．05）;仅少数病例（4．48％）出现色素减退、色素沉着及瘢痕等不良反应。结论752nm紫翠宝石激光治疗太田痣效果明显,安全性高,可视为是目前行之有效的较好方法之一。     

内膜下血管成形术治疗下肢动脉硬化闭塞症的初步报道

目的:总结内膜下血管成形术(SIA)治疗下肢动脉硬化闭塞症的疗效。方法:平卧位、局麻下,于病肢同侧顺行或逆向穿刺股总动脉,插入6F鞘管,造影证实闭塞病变。在电透荧屏监控下,通过鞘管插入5F的KMP导管,在0.035超硬导丝作用下,于闭塞端的侧壁内膜下开创一个夹层平面,随着导丝在内膜下向前延伸,其顶端会形成半圆形的环。然后,导管和导丝环通过内膜下的夹层持续前进;当到达闭塞段远端时,将KMP导管的顶端转向腔内,使导丝和导管进入真腔。然后退出导管,顺着导丝插入7mm×40mm或合适大小的球囊导管,应用709～811kPa压力,逐步扩张再管化段。术中如发现新形成的通道受压而呈弹性回缩现象,可以植入8mm×40mm或适当大小的镍钛合金自膨式支架。最后通过导管或鞘管造影,检测血流通道是否再建成功。结果:本组共13例,男9例,女4例;左下肢5条,右下肢6条,双下肢2例(4条),共15条肢体。11例中计13条肢体获得成功,成功率为86.7%。其中股动脉段闭塞5例(7条肢体),髂动脉闭塞段4例(4条肢体),胫闭塞段2例(2条肢体)。分别随访3～9个月(平均4.3月),均维持通畅。复查ABI为0.65～0.87,平均0.75,与术前比较有显著性差异(P<0.01)。结论:SIA是一种应用腔内血管外科技术治疗下肢动脉硬化闭塞症的新方法,操作简便微创,安全、有效而经济,近期     

长脉冲翠绿宝石激光永久性脱毛疗效分析

目的评价长脉冲翠绿宝石激光对人体不同部位永久性脱毛的疗效。方法用Gentle LASE脉冲激光对身体各部位进行脱毛,回顾性分析达到永久性脱毛效果的298个部位的脱毛情况。结果5次脱毛后,四肢、腋窝脱毛率平均为82.50%~94.00%,男性腮部和女性唇周平均分别为82.50%、85.00%;而4次脱毛后,发际、骶部脱毛率平均分别为92.56%、94.87%。男性腮部和女性唇周5次脱毛后,脱毛率分别与其他各组之间两两比较差异均有统计学意义(P<0.05);而男性腮部和女性唇周之间,以及其他各组之间两两比较,差异均无统计学意义(P>0.05)。脱毛后,各部位毛发再生延迟,且随脱毛次数增加而延迟时间愈长(r为0.33~0.80)。男性腮部和女性唇周总脱毛次数较多,平均分别为8.00次和7.31次,次数多于其余各部位,效果差异有统计学意义(P<0.05),其余7组脱毛次数平均为3.25~4.83次,各组之间比较,差异无统计学意义(P>0.05)。总不良反应发生率为7.38%。结论长脉冲翠绿宝石激光对四肢、腋窝、发际脱毛效果较好,疗效优于女性唇周和男性腮部;随脱毛次数增多毛发再生延迟。     

Application of excimer laser coronary angioplasty (ELCA) in bifurcation lesions

. Excimer laser coronary angioplasty (ELCA) offers a unique approach to the treatment of bifurcation lesions that continues to present a challenge in percutaneous coronary intervention. Debulking plaque prior to stenting or balloon angioplasty has demonstrated significant improvement in the treatment of bifurcation lesions. Clot dissipation properties of excimer laser combined with its ability to debulk, makes this device unique when applied to thrombus-laden bifurcation lesions. ELCA is the only debulking technique that allows retention of two guide wires with resultant protection of the bifurcation vessels during the debulking procedure. We herein describe three patients with unstable angina who underwent a debulking procedure with ELCA involving application of single and double wire techniques. These three cases illustrate two different techniques used for debulking bifurcation lesions. Both single and double wire techniques are described. ELCA can be used safely and effectively in high-risk patients with bifurcation lesions, even in the presence of thrombus.     

Flashlamp exited pulsed dye laser and electrohydraulic lithotripsy: in vitro study on tissue effects

Intracorporal lithotripsy has gathered momentum in the management of gallstone disease due to the increasing sophistication of technical equipment for the percutaneous, as well as the retrograde-endoscopic route. Laser-induced shock wave lithotripsy (LISL) and electrohydraulic lithotripsy (EHL) have proved feasible by allowing reliable fragmentation of biliary calculi. Evaluation of therapeutic risks, e.g., effects of accidental irradiation of the gallbladder wall, has been performed in small sample sizes only. We investigated the effects of LISL and EHL on multiple sets of human and porcine gallbladders under in vitro conditions. Gallbladders were freshly harvested, mounted, and immersed in different mediums (normal saline, blood, bile). They were swiftly exposed to LISL (Pulsolith?) and EHL (Lithotron EL 23?) under differing experimental conditions (energy setting, pulse mode, exposition time, medium, probe pressure) and subjected to standard procedures for morphometric evaluation (Bioquant?). Tissue effects were described by the depth (d) and width (w) of the cratered lesions, as well as the extension of the damage in the surrounding tissue(s). Serial cuts of the exposed areas yielded 894 section for morphometric analysis. Multivariate analysis of variance (MANOVA) revealed a significant effect of laser energy (p[d] less than 0.002, p[w] < 0.05, p[s] < 0.05), medium (p[d] less than 0.03, p[w] < 0.001, p[s] < 0.04, and exposition time (p[d] less than 0.001, p[s] < 0.001) on the degree of tissue lesion.(ABSTRACT TRUNCATED AT 250 WORDS)     

Excimer laser angioplasty: Quantitative comparison in vitro of three ultraviolet wavelengths on tissue ablation and haemolysis

The effects of three ultraviolet excimer laser wavelengths on normal and atheromatous human cadaver aortic wall are presented. Ultraviolet radiation successfully ablates vessel wall; the dose response is greatest at 249 nm followed by 193 nm and 351 nm, where the effect is negligible for the equivalent energy dose. Wavelengths 249 and 193 nm have a selective effect on fibrous atheroma; ablation proceeds at a higher rate in this tissue. Non-linear effects observed at 249 nm may be due to thermal as well as photoablative mechanisms. In addition, blood samples were exposed to all three wavelengths and potassium concentrations were measured; the dose of energy required to produce tissue ablation may also produce significant haemolysis and hyperkalaemia at 249 and 193 nm but not with 351 nm. This finding may be important for coronary angioplasty but less so for peripheral work. The wavelength that produces the strongest dose response is 249 nm; this is the wavelength for which a fibre-optic delivery system should be developed.     

In vitro effects of Nd:YAG laser radiation on blood: A quantitative and morphologic analysis

Use of the Neodymium: yttrium -aluminum -garnet (Nd:YAG) laser to recanalize stenosed arteries may require delivery of the beam through blood. To assess the degree of hemolysis and debris formation, 54 samples of citrated whole blood were exposed to Nd:YAG laser radiation of varying powers (10, 20 and 30 watts) and duration (1, 2.5 and 5 seconds). Compared to control samples which were not subjected to laser light, there was no significant decrease in hematocrit (41 to 40.5 +/- 5%), hemoglobin concentration (13.8 to 13.8 +/- .06 g/1OO ml), or increase in "free" hemoglobin concentration. Debris weight (from .45 +/- .002 to .45 +/- .002 mg), as well as the white blood cell count, was also not significantly changed (from 5,400 to 5,200 +/- 240 WBC/cm). Light microscopy examination of debris from samples of whole blood, washed erythrocytes, and platelet-rich plasma subjected to the laser at 30 watts for five seconds failed to demonstrate the presence of membrane denaturation of blood elements, as compared with the morphologic changes observed in whole blood samples exposed to a "hot tip" rather than Nd:YAG laser radiation. Nd:YAG laser can be used intravascularly without fear of hemolysis or debris "micro-embolization" up to a power of 30 watts for five seconds.     

Percutaneous peripheral laser angioplasty with a pulsed Nd-YAG laser and sapphire tips

Percutaneous transluminal laser angioplasty with a pulsed Nd-YAG laser (1064 nm wavelength, 100s pulse duration, up to 0.4 J per pulse, 10 Hz repetition rate) coupled to optical fibres with sapphire tips of 1.8 and 2.2 mm diameter was performed under experimental conditions and then in 30 chronic occlusions of femoral and popliteal arteries in 22 patients.The experimental study in 11 human cadaverous arteries revealed that this laser system was effective in the recanalization of seven femoropopliteal occlusions, but the relative rigidity of the sapphire-tipped contact probe prevented its access to two infrapopliteal vessels. Two perforations occurred after the recanalization of 18 and 15 cm, respectively.Clinically the procedure was successful in 17 out of 25 sessions (68%). The probe formed a primary channel of at least 2.0 mm width which was further dilated by conventional balloon catheter. Ankle/brachial systolic pressure index (ABPI) increased from 0.43±0.13 to 0.79±0.21 after the procedure. In eight cases complications occurred. Two reocclusions were treated by Streptokinase infusion, two procedures were repeated 2 months later, one patient was referred to elective bypass surgery, and three patients were treated conservatively. Six patients were followed-up for more than 6 months. In one patient claudication of 400 m reappeared. ABPI showed a moderate decrease from 0.84±0.20 to 0.69±0.19.These first results are encouraging and it is likely that this method could become an important adjunct to balloon angioplasty.     

Helium-neon laser: A contraindication for infected wounds? In vitro study on pseudomonas aeruginosa

The purpose of this investigation was to examine the susceptibility ofPseudomonas aeruginosa to helium-neon (He-Ne) laser in order to gain an insight into the clinical implications for this type of low-level laser therapy (LLLT) in the treatment of infected wounds. Suspensions, in the presence and the absence of methylene blue (MB, 0.001% w/v), were exposed to the light from a 9 mW He-Ne laser for 5 and 50 min. Exposure of samples without MB did not affect the viability of this organism based on the lack of significant differences in the number of colony forming units (CFU) between irradiated and control samples. In the presence of MB, statistically significant mean reductions in CFU of 39.5% (22.6 J cm^-2) and 58.2% (226 J cm^-2) were found, and growth-free zones in irradiated confluent platings could be observed. Since no logarithmic reductions were achieved, the clinical implementation of He-Ne laser as a bactericidal agent seems to be of no relevance yet. Otherwise, no stimulation of bacterial growth was observed. Therefore, infection as a contraindication for LLLT should be excluded.     

膝下动脉球囊血管成形术治疗重症下肢缺血的临床研究

目的 评价膝下动脉闭塞首选球囊血管成形术的临床治疗效果.方法 2005年12月至2009年5月,对于连续收治且符合手术指征的54例(61条肢体)膝下动脉重度狭窄或闭塞的重症下肢缺血患者,采用膝下动脉球囊血管成形术进行治疗.其中男性37例,女性17例,平均年龄66岁.术前踝肱指数平均0.43±0.27.根据病变部位选择手术方法,膝下动脉病变首选球囊血管成形术,合并髂股动脉病变同时进行血管重建(支架置入或动脉旁路术).结果 髂股动脉重建(28条肢体行支架置入,5条肢体行动脉旁路术)均一期成功.膝下动脉球囊血管成形术57条肢体获得一期成功,技术成功率93.4%.围手术期主要并发症为小腿血肿3例(4.9%),膝下截肢2例(3.3%).术后踝肱指数增加至0.86±0.21,与术前相比差异有统计学意义(P<0.01).本组平均随访时间(16±11)个月,一期通畅率61.1%,21条肢体发生再狭窄(38.9%),其中10条肢体再次接受外科干预,二期通畅率75.9%.截肢3条肢体,总的救肢率91.8%.结论 球囊血管成形术是治疗重症下肢缺血安全有效的方法,可以作为膝下动脉病变首选的外科干预手段.     

THANK重组腺病毒肝癌基因治疗的实验研究

目的 在构建THANK腺病毒载体的基础上，在裸鼠体内观察THANK基因转移对SMMC-7721细胞作用。方法 用THANK重组腺病毒，感染SMMC-7721细胞，获取高表达THANK基因的7721细胞，将不同7721细胞接种裸鼠，观察THANK基因转移后7721细胞的成瘤性变化，包括肿瘤生长的大小、速率，肿瘤重量、裸鼠生存期变化以及成瘤后肿瘤组织及脾脏的微观结构变化。结果 THANK在7721细胞中的表达可抑制肿瘤细胞的生长，激发机体的抗肿瘤免疫，抑制初次和再次接种的亲代7721细胞的生长，降低了7721细胞的成瘤性。光镜和电镜观察均可发现THANK的转染使得7721细胞的坏死和凋亡比例有所增高，提示THANK在裸鼠体内可能通过某种机制增强了7721细胞的凋亡比例。结论 THANK在裸鼠体内可诱发有效的抗肿瘤免疫。     

胶原在血管成形术后再狭窄中表达和意义的实验研究

目的观察PTA后胶原含量在血管壁各层随时间的演变规律,探讨胶原在血管再狭窄过程中的表达及意义。方法30只大鼠制作成颈动脉再狭窄动物模型,取损伤后1、3、7、14、28和42天6个观察点,对胶原纤维进行Masson染色。分析胶原与内膜增生和血管重塑的关系。结果①内膜的胶原第7天即开始表达并逐渐增多,第28天基本稳定。中膜胶原含量在整个过程中无统计学差异。外膜胶原第7天达高峰,后逐渐下降。②内膜、外膜胶原密度分别与内膜、外膜面积有相关性,内膜、中膜、外膜胶原密度都与管腔面积丢失率具有明显的相关性。中膜、外膜胶原密度与外弹力板面积缩小率具有明显的相关性。内膜、外膜胶原密度与内膜面积增长率具有明显的相关性。内膜胶原密度与内膜PCNALI有负相关性。③内膜胶原光密度在第7天即达高峰,随后逐步下降。中膜胶原光密度整个过程中无显著差异。外膜的胶原光密度PTA后第1天即开始上升,到第7天达高峰,随后逐步降至对照水平。结论再狭窄过程中胶原在内膜、外膜含量明显升高,中膜胶原含量基本保持不变。它们共同参与狭窄,内膜的胶原主要与内膜增生有关,中膜和外膜胶原主要与重塑有关。     

卡托普利对血管成形术后再狭窄作用的实验研究

目的探讨卡托普利对血管成形术后再狭窄的干预作用。方法SD雄性大鼠60只,分单损组、干预组和对照组。单损组采用改良导丝法制作大鼠颈动脉再狭窄模型。干预组将卡托普利研磨成粉状,生理盐水稀释配制成5mg/ml溶液,分别于制模前6 d开始按10 mg/(kg.d)剂量经灌胃针给予大鼠至术后各时间点。对侧颈总动脉作为假手术对照组。每组各时间点6只大鼠,于制模后1天、4天、7天、14天及28天原位灌注固定取材。根据HE染色标本情况,选血管形态结构完整的50个标本,进行HE染色,采用病理图像分析系统染色片进行形态计量分析。结果损伤后从第7天起新生内膜厚度和面积逐渐增加,到28天达峰值;与单损组比较,干预组血管壁三层厚度无显著差别,干预组第14、28天新生内膜面积显著减低。狭窄率于血管损伤后逐渐增加,到28天达峰值,与单损组比较,干预组在14天和28天狭窄率明显变小,各时间点内弹力板面积、外弹力板面积及重塑指数两组之间无显著差别。结论卡托普利减小大鼠颈动脉损伤后新生内膜面积及狭窄率,抑制新生内膜形成,但不改变内、外弹力板面积及重塑指数,不影响血管收缩性重塑。     

A comparison study of the efficacy and side effects of different light sources in hair removal

Unwanted hairs are a common problem in which different light sources were developed as the treatment of choice. Alexandrite laser, diode laser, and intense pulsed light (IPL) were clinically used for this purpose with long-term scarce comparative results. The objective of the study was to compare the clinical efficacy, complications, and long-term hair reduction of alexandrite laser, diode laser, and IPL. Clinical trials on 232 persons using diode, alexandrite, laser and IPL were conducted. The number of sessions to reach optimal result varied between 3 and 7. Then the side effects were evaluated. Six months after the last session, optimal hair reduction was observed with no significant differences between the light sources, but a hair reduction was found to be higher using the diode laser. Side effects were observed with all light sources but more frequently with diode. Our findings indicate that all three light sources tested have similar effects on hair removal and in Iranian patients, using lower wavelengths minimizes the side effects.     

Holmium and thulium lasers: Comparison of solid state systems with potential applications for laser angioplasty

Three different Mid-infra-red laser systems with potential applications in peripheral and coronary angioplasty have been investigated: Free running Ho-Tm-Cr-YAG, Q-switched Ho-Tm-Cr-YAG and free running Tm-Cr-YAG. In vitro ablation experiments were performed with atherosclerotic plaque, using both single quartz fibres and multifibre ring catheters. Despite high ablation rates, the free running Ho-Tm-Cr-YAG laser caused thermal and acoustic damage to the tissue with carbonization effects, charring of the crater edges and severe vacuole formation. Using Q-switched Ho-Tm-Cr-YAG irradiation, thermal and acoustic side-effects were reduced, but the energy available from the system was too low to reach the ablation threshold with ring catheters. A free running Tm-Cr-YAG laser also showed limited tissue damage but its output energy was in excess of 1 J, allowing, therefore, effective catheter ablation.