输尿管镜联合钬激光治疗输尿管上段结石:附205例报告

目的 探讨输尿管镜联合钬激光治疗输尿管上段结石的效果和安全性.方法 回顾性分析205例输尿管上段结石患者行输尿管硬镜钬激光碎石治疗的临床资料,其中男91例,女114例,结石位于单侧188例,双侧17例,炎性息肉引起输尿管腔明显狭窄者12例.结石长径0.8～1.4 cm.结果 192例一次性碎石成功,单次碎石成功率为93.7%(192/205).9例有较大结石碎片(4～6 mm)残留于肾或输尿管内,4例在碎石过程中结石冲入肾内,其中1例较大结石(1.4 cm)移位至肾盂后改行PCNL,其余3例留置双J管改行ESWL,均治愈.19例合并炎性息肉同期行激光烧灼.手术时间15~90min,平均30 min.住院时间2~9 d,平均3.5 d.198例患者在门诊获得随访,随访时间3～24个月,平均6个月,结石均排尽.结论 输尿管镜联合钬激光治疗输尿管上段结石的一种比较理想的腔内碎石技术,其碎石成功率高,并发症发生率低,创伤小,患者术后恢复快,而且可同期处理结石合并炎性息肉和狭窄.     

输尿管镜钬激光治疗小儿尿路结石19例报告

目的：探讨输尿管镜钬激光治疗小儿尿路结石的效果及并发症。方法：对19例小儿尿路结石（输尿管结石16例,膀胱结石3例）患者进行输尿管镜钬激光碎石治疗。结果：18例患儿均成功碎石并排出结石,1例将结石推入肾盂行ESWL术。19例患儿均无输尿管损伤和穿孔。结论：在明确掌握适应证和操作熟练的情况下,输尿管镜钬激光碎石是治疗小儿尿路结石的理想方法。     

The ablation threshold of Er:YAG and Er:YSGG laser radiation in dental enamel

. The scientific investigation of fundamental problems plays a decisive role in understanding the mode of action and the consequences of the use of lasers on biological material. One of these fundamental aspects is the investigation of the ablation threshold of various laser wavelengths in dental enamel. Knowledge of the relationships and influencing factors in the laser ablation of hard tooth tissue constitutes the basis for use in patients and the introduction of new indications. The present paper examines the ablation threshold of an Er:YAG laser (λ=2.94 μm) and an Er:YSGG laser (λ=2.79 μm) in human dental enamel. To this end, 130 enamel samples were taken from wisdom teeth and treated with increasing energy densities of 2–40 J/cm². The sample material was mounted and irradiated on an automated linear micropositioner. Treatment was performed with a pulse duration of τ_P(FWHM)≈150 μs and a pulse repetition rate of 5 Hz for both wavelengths. The repetition rate of the laser and the feed rate of the micropositioner resulted in overlapping of the single pulses. The surface changes were assessed by means of reflected light and scanning electron microscopy. On the basis of the results, it was possible to identify an energy density range as the ablation threshold for both the Er:YAG and the Er:YSGG laser. With the Er:YAG laser, the transition was found in an energy density range of 9–11 J/cm². The range for the Er:YSGG laser was slightly higher at 10–14 J/cm². Paper received 15 May 2001; accepted after revision 14 January 2002. Correspondence to: Dr Christian Apel, Department of Conservative Dentistry, Periodontology and Preventive Dentistry, University of Aachen, Pauwelsstr. 30, D-52074 Aachen, Germany. Tel.: +49 241 8089088; Fax: +49 241 8888468; e-mail: capel@post.klinikum.rwth-aachen.de     

Arthroscopic shoulder surgeyr with three different laser systems: An evaluation of laser applications

Twelve cadaveric shoulder arthroscopies were performed to evaluate the use of lasers as an adjunctive tool in arthroscopic shoulder surgery. The three most common lasers historically used in orthopedic surgery were examined: Holmium:YAG, Neodymium:YAG, and the CO₂. The following parameters were evaluated for each laser system: (1) each of use of the laser system and handpiece; (2) ability to excise and trim bursae, synovium, ligament, tendon, bone, and articular cartilage; and (3) ability to contract ligaments and capsule by heat transfer. None of these lasers efficiently cut bone, whereas all three systems readily debrided the soft tissues around the shoulder. The free-beam Ho:YAG and CO₂ systems heat contracted soft tissues with more control than the contact Nd:YAG. The fiberoptic delivery system of the Neodymium:YAG and Holmium:YAG laser performed well in the saline arthroscopy, and the CO₂ delivery system was cumbersome. Overall, the CO₂ system removed tissue better than the others, but its difficult use favored the Holmium laser as the best overall current laser system for shoulder arthroscopy.     

Influence of the pulse duration of an Er:YAG laser system on the ablation threshold of dental enamel

. The present study examines the dependence of the ablation threshold on the duration of the applied laser pulses in the dental enamel of human wisdom teeth. To this end, 600 treatments with the Er:YAG laser (λ=2940 nm) were carried out on a total of 50 extracted teeth. The laser light was coupled into a fluoride glass light guide for this purpose, in order to ensure almost gaussian distribution of the light in a radially symmetrical beam. The beam diameter on the specimen was 610 μm. The radiant exposure on the tooth surface was varied between 2 and 20 J/cm², while the duration of the pulses applied was changed in four steps from 100 μs to 700 μs. The irradiated tooth surfaces were examined for visible signs of ablation under a reflected-light microscope. The experiments revealed that, when pulses of shorter duration are used, the limit at which ablation sets in is reduced by up to approx. 3 J/cm². This expands the ablation threshold range of Er:YAG laser radiation to between 6 and 10 J/cm². In this context, both the pulse duration and the radiant exposure have a statistically significant influence on the ablation threshold (logistic regression, p<0.0001). Although the ablation threshold of the dental enamel can be changed by varying the pulse duration of the Er:YAG laser, no clinical consequences can be expected, as the shift is only slight. Paper received 11 March 2001; accepted after revision 22 May 2002. Correspondence to: Dr Christian Apel, Department of Conservative Dentistry, Periodontology and Preventive Dentistry, University of Aachen, Pauwelsstrasse 30, D-52074 Aachen, Germany. Tel.: +49 241 8089088; Fax: +49 241 8082468; e-mail: capel@ukaachen.de     

A one-dimensional mathematical model of laser induced thermal ablation of biological tissue

A mathematical model of ablation of tissue by an incident laser beam is formulated in terms of a series of layers in which laser power is absorbed and water and tissue vaporized. Thermal energy is also deposited and removed by conduction. Time dependent mathematical equations are set up for these processes; they are solved numerically. The model assumes that absorption is dominant over scattering, so that it is possible to calculate the thickness of the vacuolated zone. The evolution of the ablating surface is found.     

输尿管软镜联合硬镜与经皮肾镜钬激光治疗肾盂大结石临床疗效对比研究

目的 输尿管软镜联合硬镜与经皮肾镜钬激光治疗肾盂大结石临床疗效对比研究.方法 回顾和分析本院2010年7月～2012年8月应用输尿管软镜联合硬镜碎石术治疗肾盂大结石33例与采用经皮肾镜钬激光治疗肾盂大结石37例的治疗效果对比.结果 采用输尿管软镜结合硬镜碎石术治疗肾盂大结石的碎石率为95.3％,高于经皮肾镜钬激光法碎石术的90.5％.输尿管软镜结合硬镜的碎石排净时间为12d,显著少于经皮肾镜钬激光碎石术的14d.结论 采用输尿管软镜结合硬镜碎石术治疗肾盂大结石临床效果相比于经皮肾镜钬激光碎石术较好.     

Er:YAG laser ablation of cerebellar and cerebral tissue

. With the availability of suitable fibres, the Er:YAG laser has become an indispensable tool for invasive neurosurgical applications as a source of precise ablation. The aim of this study was to investigate the ablative effects of the Er:YAG laser on brain tissue. The response of neuronal tissue to 2.94 μm Er:YAG laser irradiation was investigated on excised rat brain specimens. Ablation craters were created in cerebral and cerebellar tissues using 0.3, 0.5 and 1.0 J single pulses of 150 μs duration. The corresponding average irradiances were 37.7 J/cm², 62.9 J/cm² and 125.8 J/cm², respectively. Craters were checked qualitatively, crater dimensions were measured and compared, and volume of ablated tissue was estimated. Laser-induced crater dimensions were found to be significantly different at different energy levels applied. Moreover, dimensions of craters on cerebral and cerebellar tissues were significantly different in terms of dimensions. We observed that with the Er:YAG laser ablation craters were created with practically no thermal damage to adjacent tissues. The differences observed in the response of cerebral and cerebellar cortical tissues were dependent on the anatomical and chemical differences. Paper received 3 August 1999; accepted after revision 26 June 2000.     

One hundred consecutive treatments with holmium: YAG laser for pulmonary bullae: especially in conjunction with gelatin-resorcinol formaldehyde-glutaraldehyde glue adhesion

BACKGROUND AND OBJECTIVE: We have widely used a Ho:YAG laser to treat bullae thoracoscopically. STUDY DESIGN/MATERIALS AND METHODS: Bullae with broad necks were treated with a Ho:YAG laser thoracoscopically. Because one patient relapsed after application of fibrin glue in the early period, a DEXON (polyglycolic acid) mesh patch soaked in fibrin glue was used through a 2-cm opening in the subsequent cases. Lastly, gelatin-resorcinol formaldehyde-glutaraldehyde (GRFG) glue was applied through a 5-mm opening instead of a DEXON mesh after coagulation. RESULTS: In the 38 patients patched with DEXON mesh soaked in fibrin glue and 56 patched with GRFG glue after coagulation, none relapsed. CONCLUSION: Combined uses of fibrin glue plus DEXON mesh or GRFG glue were effective when bullae were treated with the Ho:YAG laser. However, the wound was smaller and more cosmetic in the GRFG glue group than in the DEXON mesh plus fibrin glue group.     

Holmium:YAG laser treatment of ureteral calculi: a 5-year experience

The purpose of this study was to provide an account of the 5-year experience we have gained using holmium:yttrium–aluminium–garnet (Ho:YAG) lasertripsy in the treatment of ureteral stones. One-hundred thirty-seven transurethral ureterolithotripsies were performed in 131 patients. A Ho:YAG laser device, fibres with diameters of 360 and 550 μm, a video camera as well as semi-rigid and flexible ureterorenoscopes were used. Results showed that the direct success rates—which meant stone-free ureters on the first post-operative day—in the upper, middle and lower ureters were 84.6, 88.7 and 94.8%, respectively. The final success rates—which meant stone-free ureters 4 weeks after the operation without a second intervention—were 84.6, 96.7 and 96.7%, respectively. The pulsatile Ho:YAG laser beam fragmented all kinds of stones easily. No ureteral stricture or reflux was identified during the follow-up period. The advantages of Ho lasertripsy outweighed its disadvantages. Based on our experience, the Ho:YAG laser is one of the most effective and safest energy sources in the treatment of ureteral calculi.     

静脉内射频消融术与激光消融术治疗大隐静脉曲张的比较

目的 比较静脉内射频消融术和激光消融术治疗大隐静脉曲张的安全性和有效性.方法 回顾性分析2018年4～12月接受静脉内射频和激光消融术治疗的80例大隐静脉曲张患者临床资料,其中射频组39例,激光组41例.比较两种方法的手术并发症发生率、术后疼痛视觉模拟评分(visual analogue scale,VAS)、静脉临床...     

Clinical,histologic, and ultrastructural evaluation of tattoos treated with three laser systems

We examined the response of tattoo pigments treated with three commercially available lasers: Q-switched ruby, Q-Switched neodynium:yttrium, aluminum, garnet (Nd:YAG), and the alexandrite. Tattoos applied to hairless guinea pigs and treated with the aforementioned lasers were evaluated clinically, histologically, and ultrastructurally. Clinical evaluation showed red brown, dark brown, and orange pigment responded best to the Nd:YAG laser (1064 nm). The alexandrite laser was most effective for removing blue and green pigment, the Q-switched ruby laser was most effective for removing purple and violet pigment, and the NdYAG laser (532 nm) removed red pigment the best. Black pig ment was lightened equally with the Nd:YAG laser (1064 nm) and (532 nm) and the alexandrite laser (755 nm). No clinical scarring was observed; however, some colors turned black after treatment. Histologic and ultrastructural examination showed epidermal and dermal damage to be most evident after treatment with the Nd:YAG laser. Our study shows that certain tattoo pigments respond better to different laser systems. © 1994 WiIey-Liss, Inc.     

钬激光前列腺剜除术与前列腺汽化电切术治疗良性前列腺增生的疗效比较

目的 比较经尿道前列腺汽化电切术与经尿道钬激光前列腺剜除术治疗前列腺增生症 的疗效。 方法 将160例前列腺增生症( benign prostatic hyperplasia,BPH)患者随机分为两组,每组80例,分别用 TUVP 及HoLEP 治疗 。比较两种术式 的手术时间、手术出血量、 膀胱冲洗时间 、住院时间、并发症及近期疗效等指标 。结果 两组患者术后国际前列腺症状评分 （IPSS）、生活质量评分（ QOL）、最大尿流率和残余尿量均较术前明显改善,但两组上述指标间比较差异无显著性差异 。HoLEP组术中出血量、术后膀胱冲洗时间、住院时间明显短于TUVP组;并发症发 生率低于TUVP组。 结论 TUVP 及HoLEP 治疗前列腺增生症均有效;HoLEP的手术安全性优于TUVP。     

电刀和钬激光腔内切开对小猪肾盂输尿管连接部的形态学影响

目的探讨电刀和钬激光腔内切开小猪肾盂输尿管连接部(UPJ)后形态学的变化。方法采取大体、光学及电镜观察比较二种方式内切开后的愈合效果。结果大体观可见所有小猪UPJ处均未见尿性囊肿形成,与周围组织粘连轻微。电镜下均可见肌丝排列,大部分肌层已恢复连续性。光镜下见黏膜已恢复连续性,肌层的连续性的恢复主要限于内1／2～2／3区域。左右两侧评分分别为4．23±1．18和3．78±0．46,差异无统计学意义(P>0．05)。结论采用电刀和钬激光切割小猪UPJ后其形态学改变大致相同,在组织学愈合上差异无统计学意义(P>0．05)。     

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.     

Femtosecond laser for glaucoma treatment: a study on ablation energy in pig iris

Safe and effective laser ophthalmic surgery requires a fine balance between the efficiency of laser delivered and the degree of collateral side damage. The laser–ocular tissue interaction process is reliant on three main variables, namely, wavelength, pulse duration, and deposited energy. A certain amount of energy is needed to achieve ablation, while too much energy can result in unwanted collateral thermal damage. In our work the relationship between energy deposition and ablation effect is studied by an in-vitro experiment using an 800-nm wavelength 150 fs-pulse-duration laser system. This experiment aims to validate the probability of decreasing the supplied energy during glaucoma surgery by femtosecond laser. Our results show that less energy is needed using femtosecond laser than that using a longer pulse laser.     

Mid-infrared laser ablation of the cornea: a comparative study.

The ablation thresholds and patterns of collateral damage in cornea produced by Er:YAG (2.94 microns) and Er:YSGG (2.79 microns) lasers were measured. Two different pulse durations, 200 microseconds (normal spiking mode) and 100 ns (Q-switched mode), were used at both wavelengths. In the normal spiking mode, damage zones of 16 +/- 2 microns and 39 +/- 7 microns and ablation thresholds of 250 +/- 20 mJ/cm2 and 420 +/- 35 mJ/cm2 were measured at 2.94 microns and 2.79 microns, respectively. In the Q-switched mode, damage zones of 4 +/- 2 microns and ablation thresholds of 150 +/- 10 mJ/cm2 were found irrespective of the laser used. The similarity between the results using the Er:YAG and Er:YSGG lasers in the Q-switched mode suggest that either laser can be used with equal effectiveness for corneal trephination.     

Erbium-YAG and holmium-YAG laser ablation of bone

Results are presented for the latent heat of ablation of bone using an erbium-YAG laser operating at 2.9m, and a holmium-YAG laser operating at 2.1m. The values are 8.2±1.0 kJ cm^–3 and 18±2.0 kJ cm^–3, respectively. Secondary damage to surrounding tissue is found to extend approximately 5m with the erbium laser and is greatly increased to 80m with significant charring in the case of holmium. These secondary damage zones are much smaller than those produced by the CO₂ laser.