CO2激光结合Nd:YAG激光治疗色素痣的临床观察

目的：评价CO2激光结合Nd：YAG激光治疗色素痣的疗效。方法：先用CO2激光选择连续脉冲，小功率输出，烧灼皮损到周围正常皮肤水平，继之用Nd：YAG激光治疗，治疗面部色素痣128例、768个皮损。结果：Ⅰ、Ⅱ级(痊愈 显效)率为96．76％。治疗次数平均为1.32次。结论：采用CO2激光结合Nd：YAG激光治疗面部色素痣疗效肯定，治愈率高，疗程短。多数患者无明显瘢痕形成。     

Experimental study of partial liver resection with a combined CO2 and Nd:YAG laser

The use of the CO₂ laser in liver surgery is mainly limited by the lack of coagulation of the larger vessels. In an experimental study, partial liver resections were performed on pigs with a Nd:YAG as well as with a combined CO₂ and Nd: YAG laser. The best cutting efficiency was obtained with the CO₂ laser. On the other hand, the Nd:YAG laser and the combined laser sources showed excellent hemostasis at the cutting edge corresponding with a width of necrosis at about 5 mm in histomorphometric examination and zones with histologically different characteristics. Rebleedings from the resection lines were avoided in all cases using the combined CO₂ and Nd:YAG laser.     

Urologic dosimetry studies with the Nd:YAG and CO2 lasers: bladder and kidney

Dose recommendations for the use of the Nd:YAG and CO2 lasers have been accepted with little laboratory analysis. We have examined both endoscopic and open applications in the bladder and open applications on the kidney with the lasers over a variety of power and pulse duration settings. In addition, we have studied the effect of varying the temperature of the tissue and irrigation solution on the depth of penetration. We found that with the Nd:YAG laser, the maximum depth of penetration in our animal model was only 2.62 mm in the bladder. This occurred during an endoscopic treatment with settings of 50 W at 4 seconds with irrigation solution of 25 degrees C. The depth of penetration using current recommendations of 40 W for 2 seconds was less than 1 mm at all temperatures. Room temperature irrigation solution may be the ideal compromise, but higher-power long-pulse durations or repeated treatments to the same area may be necessary to achieve penetrations of 3-5 mm. In open applications on bladder and kidney, the maximum depth of penetration in our animal model was 2.75 mm, which was found during a treatment with settings of 60 W at 4 seconds with the kidney parenchyma at 25 degrees C. Using the CO2 laser on open applications of bladder strips, we obtained a maximum depth of penetration of 1.75 mm at 30 W of power for 1/2 second at 85 degrees C tissue temperature. Unfortunately, penetration by the CO2 laser is accompanied by vaporization of tissue, leaving a large crater. Minimal injury exists beyond this area. In the kidney, we obtained a maximum depth of penetration of 1.75 mm at 30 W of power at 25 degrees C and 20 W of power at 2 degrees C each for 1/2 second.     

CO2 and Nd:YAG laser systems in microsurgical venous anastomoses

Summary A comparative study was undertaken in 81 rats to investigate a CO₂ and Nd:YAG laser system for laserwelded anastomosis of the femoral vein. Conventionally sutured anastomoses (CMSA) served as controls. Laserwelded anastomosis (LAMA) was easier and could be performed 30% faster than CMSA. Postoperative investigations included patency tests, postmortem examinations and light and electron microscopy. Aneurysms were not seen. Foreign-body reaction was more pronounced in CMSA. Patency rates for CO₂-LAMA and CMSA were equal, whereas Nd:YAG-LAMA resulted in significantly higher rate of early postoperative thrombosis (P<0.01). Because of its physical properties, the CO₂-laser system seems to be better suited for laser welding of delicate structures such as the rat femoral vein.     

Observations on the simultaneous use of CO2 and Nd:YAG lasers in neurosurgery

Seven cases of cerebral tumors (four deep-seated sovratentorial gliomas located in motor area, occipital region, parietal region and frontal region; one deep-seated cystic cerebellar spongioblastoma; one sphenoidal wing meningioma, and one spinal cord intradural tumor) were simultaneously irradiated in the same area with two sources (CO₂ and Nd:YAG). Using CO₂ and Nd:YAG simultaneously, a larger and deeper lesion was obtained. The main bulk was irradiated with two sources free hand. The implant with the two sources was connected to the operating microscope. The rise in temperature, 3 mm from the border of the lesion, was similar to that obtained with Nd:YAG alone. Hemostasis was not impaired. In comparison with the single sources, this method allows a more rapid demolition of the tumor without additional damage to the surrounding tissues.     

Clinical application of the Nd:YAG laser endoscopy

We report here our clinical experiences with Nd:YAG laser therapy, and evaluate the results of this treatment. From July 1980 to December 1981, we carried out endoscopic laser treatment for 31 patients with 33 lesions. Bleeding gastric ulcers except stomal ulcers were treated successfully. For mucosal lesions of the stomach, Nd:YAG laser irradiation was effective in extirpating them. In advanced gastric cancers, symptoms of cardiac stenosis could be relieved in 80% of the cases. Endoscopic laser therapy was also effective in 80% of postoperative stenosis in the gastrointestinal tract. It is concluded that endoscopic irradiation with the Nd:YAG laser is useful for hemostasis and also for the treatment of malignant tumors and stenosis of the gastrointestinal tract.     

Effects of Er:YAG laser and Nd:YAG laser treatment on the root canal dentin of human teeth: a SEM study

The objective of the study was to observe the morphological changes on root canal dentin after Er:YAG laser and Nd:YAG laser treatment. Twenty-one teeth biomechanically prepared were divided into three groups with seven teeth of each. Group A was unlased as a control. In group B, Er:YAG laser and in group C, Nd:YAG laser was applied to the root canal dentin. The roots were split longitudinally and examined using a scanning electron microscopy for the evaluation of debris, smear layer, and recrystallization. There was no statistically significant difference between the groups. This study indicates that laser beam is not effective in removing debris and smear layer.     

Bone ablation with Er:YAG and CO2 laser: study of thermal and acoustic effects.

A pulsed Er:YAG laser at 2.94 microns and a superpulsed CO2 laser at 10.6 microns are used to investigate bone ablation applications in otolaryngology. Quantitative measurements of mass removal and the ablation depth of cat skull bone and rat femur are presented with the Er:YAG laser at fluences of 9-117 J/cm2. Histological results show that the minimal thermal injury zone from the edge of the lesion is 5-10 microns. Comparison of the photoacoustic and thermal effects during the ablation process indicates that the temperature rise from the 10.6-microns light was higher than that from the 2.94-microns light but that the photoacoustic wave amplitude produced with the Er:YAG laser was higher than that with the CO2 laser. The fluence used for the efficient ablation of bone tissues produces a photoacoustic wave ranging from 100 to 120 dB. The ear can tolerate this level for a short time period. Results of this study suggest that the Er:YAG laser can be an important surgical tool in otolaryngology.     

Effects of Er:YAG and Nd:YAG laser irradiation on radicular dentine permeability using different irrigating solutions

BACKGROUND AND OBJECTIVES: To evaluate the effect of Er:YAG and Nd:YAG laser on radicular dentine permeability when using distilled and deionized water and 1% NaClO as irrigating solutions. STUDY DESIGN/MATERIALS AND METHODS: Thirty human maxillary canines were divided randomly into six groups. The root canals were instrumented with K files and the step-back technique. Group I, irrigation with distilled and deionized water; Group II, irrigation with 1% NaClO; Group III, irrigation with distilled and deionized water and Er:YAG laser application (140 mJ input, 61 mJ output 15 Hz, 300 pulses, and 42 J); Group IV, irrigation with 1% NaClO and Er:YAG laser application (same parameters as Group III); Group V, irrigation with distilled and deionized water and Nd:YAG laser application (150 mJ, 15 Hz, 2,25 W); Group VI, irrigation with 1% NaClO and Nd:YAG laser application (same parameters as Group V). During laser application the teeth were always filled with the irrigating solution. The tip was withdrawn gently in helicoidal movement from the apex to the cervical portion. The teeth were processed for histochemical evaluation. RESULTS: The Tukey test showed that the cervical and middle thirds were statistically similar (P > 0.05) and significantly greater than the apical third (P < 0.05). The Scheffé test showed significantly greater dentine permeability in root canals in which water and Er:YAG laser were used and were significantly different from the other treatments (P < 0.05). CONCLUSIONS: The use of distilled and deionized water and Er:YAG laser showed the greater increase of dentine permeability. The use of 1% NaClO with Nd:YAG laser, distilled, and deionized water with Nd:YAG laser and the use of water increased dentine permeability less than the other groups. The use of 1% NaClO with and without Er:YAG laser application were positioned intermediately among the treatments.     

Effects of Nd:YAG laser photoradiation on intra-abdominal tissues: a histological study of tissue damage versus power density applied

Liver, spleen, and pancreas were subjected to laser photoradiation of 50- to 100-Watt power levels. Samples were evaluated by light microscopy at 0 hours and 7, 14, and 21 days. Four zones of cellular damage were visible in liver and pancreas: coagulum, cavitation, acidophilia, and transition. Only the first three zones were clearly visible in the spleen. Mean lateral tissue penetration was 3.1 mm in liver, 3.3 mm in spleen, and 1.0 mm in pancreas. No significant increase in lateral penetration occurred with increasing power. Normal healing was observed in liver and spleen. Pancreatitis was found in all samples at 7 days postoperatively. At power levels of 80 W or less, recovery was observed. Above 80 W, pancreatic pseudocysts and necrosis led to death of the animals.     

Preliminary study of the Nd:YAG laser in canine partial nephrectomy

Partial nephrectomy is effective in the treatment of segmental renal disease but hemostasis remains a challenge. In this preliminary investigation the Nd:YAG laser was used alone or as an adjunct to the scalpel in partial nephrectomies to determine if hemostasis could be improved. A technique of 100-W laser transection with occlusion of the renal artery was effective for partial nephrectomy and achieved complete hemostasis. Conditions of patent renal artery flow or renal cooling were associated with a reduction in necrosis depth with 100-W laser partial nephrectomies. All techniques were compatible with survival over the 5-day study period.     

Q开关Nd：YAG激光和CO2激光治疗面部色素痣疗效比较

目的：观察、评价Q开关Nd:YAG激光治疗面部色素痣的治疗效果与美容效果。方法：以Q开关Nd:YAG激光（1064nm,532nm波长）和CO2激光分别对433例面部色素痣患者1458个皮损进行治疗,对照观察其治疗效果,美容效果和平均治愈次数。结果：Q开关激光组Ⅰ、Ⅱ级痊愈率为90．67％,平均治愈次数2．59次,CO2激光组为40．4％,平均治愈次数为1．85次,经统计学处理有显著差异,结论：Q开关Nd:YAG激光治疗面部色素痣,有显著的治疗效果和美容效果,CO2激光治疗面部色素痣治疗效果较好,但美容效果欠佳。     

Histologic evaluation of the pulsed Nd:YAG laser for laser lipolysis

BACKGROUND AND OBJECTIVES: Laser lipoplasty with pulsed Nd:YAG laser, widely used in Europe and Latin America, has recently been introduced in Japan and the USA. We report histologic analyses of the effects of the laser on human fat tissue. STUDY DESIGN/MATERIALS AND METHODS: Freshly excised human skin and subcutaneous fat were irradiated with the pulsed Nd:YAG laser (SmartLipo, DEKA, Italy). A 1,064 nm laser at 40 Hz and 150 mJ and 100 microseconds-long pulses were used. Methods of exposure were the same as in the clinical application. In the control group, the specimens were cannulated by the handpiece without irradiation. The tissue was studied by scanning electron microscopy and hematoxylin eosin staining. RESULTS: Scanning electron microscopy after irradiation showed greater destruction of human adipocytes than in the control. Degenerated cell membrane, vaporization, liquefaction, carbonization, and heat-coagulated collagen fibers were observed. CONCLUSIONS: Our study showed that the SmartLipo appeared to be histologically effective for destruction of human fat tissue.     

The use of the Nd:YAG laser in urology

The use of the neodymium:YAG(Nd:YAG) laser in urology in still in its infancy. To date, the most widely published application of this laser is in the treatment of bladder carcinoma. We have utilized the Nd:YAG laser in 23 treatments for superficial bladder tumors. The laser has both advantages and shortcomings, which are thoroughly addressed. In our hands the laser has been a safe instrument for the treatment of these lesions, although we do not recommend its use for tumors greater than 3 cm. We have treated two patients with invasive disease one week prior to planned cystectomy. In one case, no residual tumor was found at cystectomy, while the second patient had viable tumor only in an untreated area. Two patients were successfully treated with the laser for intractable bladder bleeding, one each with primary and secondary bladder tumor. Seven patients with condylomata acuminata were treated with laser therapy. All had excellent results without complication. One patient with urethral bleeding secondary to trauma was treated without success, while one patient with a urethral hemangioma was well treated with the Nd:YAG laser. Thus the Nd:YAG laser would appear to have a place in the urologic armamentarium, but whether it is cost-effective for widespread use remains to be seen.     

高功率YAG激光输精管凝堵法研究

选用20条薪鲜离体家兔输精管,用高功率NdYAG激光机,将光纤插入输精管腔内,以35～45 W 6种不同功率/时间凝堵试验.病理检查确定有效凝堵阈值为40 W/0.5～1 s.继而对150只家兔进行输精管穿刺激光凝堵试验.功率40 W组术后7～14 d为脱落组织阻塞,30 d炎性细胞增生,3月时管腔完全闭塞,呈3 mm小结节,病检为纤维组织增生,管周血管无病理损伤.作者认为用高功率NdYAG激光瞬间照射法,亦可用于输精管凝堵术,且具有效果确切,处理时间短等优点.     

1064-nm Nd:YAG皮秒点阵激光与超脉冲CO2点阵激光治疗面部萎缩性痤疮瘢痕的临床比较

目的 探究1064-nm Nd:YAG皮秒点阵激光与超脉冲CO2点阵激光治疗面部萎缩性痤疮瘢痕的疗 效与安全性。方法 选取2021年6月-2023年6月于我院激光科接受治疗的62例面部萎缩性痤疮瘢痕患者作 为研究对象,按照不同的治疗方法分为皮秒点阵激光组和CO2点阵激光组,各31例。皮秒点阵激光组给予 1064-nm Nd:YAG皮秒点阵激光治疗,CO2点阵激光组给予超脉冲CO2点阵激光治疗,比较两组ECCA权 重评分、疗效自评分、满意度评分及术后不良反应发生情况。结果 两组治疗后ECCA权重评分均较治疗 前降低（P ＜0.05）,且皮秒点阵激光组的ECCA权重评分高于CO2点阵激光组（P ＜0.05）;CO2点阵激光 组疗效自评分高于皮秒点阵激光组（P ＜0.05）;皮秒点阵激光组不良反应发生情况低于CO2点阵激光组 （P ＜0.05）;两组满意度比较,差异无统计学意义（P＞0.05）。结论 1064-nm Nd:YAG皮秒点阵激光与 超脉冲CO2点阵激光均能有效改善面部萎缩性痤疮瘢痕,超脉冲CO2点阵激光疗效更好,而皮秒点阵激光 不良反应发生情况更少。     

Treatment of benign, semimalignant, and malignant skin tumors with the Nd:YAG laser

Reported are first experiences with Nd:YAG laser treatment of benign, semimalignant, and malignant skin tumors in 90 patients. Treated lesions included condylomata acuminata, basal cell carcinomas, solar keratosis, squamous cell carcinomas, and secondary malignant skin tumors. First clinical and histological results are promising, but long-term follow-up is required to judge the definite efficacy of this therapeutical modality.     

Nd:YAG laser induces long-term remission in transfusion-dependent patients with watermelon stomach

Watermelon stomach (gastric antral vascular ectasia) is a rare cause of gastric bleeding which can render patients transfusion-dependent. Laser therapy can be used to stop bleeding but the long-term success of this approach is not well described. We present a retrospective analysis of 24 consecutive transfusion-dependent patients who were treated in a national referral centre with Nd:YAG laser over an 18 year period. Laser therapy stopped all bleeding in 20 patients (83%) after a median of two sessions. Median follow up was 55 months (range 9–127). Patients remained transfusion free for a median of 16 months and a second course of treatment succeeded in all those who re-bled. One gastric perforation occurred early in the series and two patients developed pyloric stenosis which was successfully treated with balloon pyloric dilatation. Oestrogens were not used in these patients. Our experience shows that long-term remission from blood transfusion is seen in most patients treated with Nd:YAG laser. If bleeding recurs, further laser treatment is usually successful.     

Effects of laser sources (argon, Nd:YAG, CO2) on the elastic resistance of the vessel wall: histological and physical study

The function of elastic elements of the vessel wall is to produce a tension suitable to resist the distension strength made by blood pressure. By producing a modification in the morphologic and structural configuration of such elastic elements, it is possible to obtain changes of the elastic resistance of the wall. The paper reports the histological and physical modifications of blood vessel walls irradiated with different laser sources.     

Endoscopic Nd:YAG laser surgery on malignant and benign lesions of the trachea and carina

A total of 47 patients with malignant and benign lesions in the trachea and carina were used to demonstrate the effectiveness of endoscopic Nd:YAG laser surgery. The histology consisted of 37 malignant and 10 benign lesions, and 23 of the patients had severe symptoms with laser surgery being performed as a lifesaving emergency. Endoscopic Nd:YAG laser treatment was able to dilate the tracheal calibers from, 2.6±0.9 mm to 6.1±1.4 mm in the emergency cases with a remarkable effect and brought relief from wheezing and dyspnea, with an objective improvement of more than 25 per cent in peak expiratory flow rate being demonstrated. Furthermore, the tracheal diameters were able to be dilated from about 7 mm to 10 mm in the non-emergency cases. A remarkable effect was achieved in patients with intraluminal or mixed types of tumors among both the emergency and non-emergency cases. The survival rates of the emergency patients in whom a remarkable effect was achieved were definitely better than those in whom only fair or poor effects were achieved and, in the non-emergency cases, similar results were demonstrated. In conclusion, the application of endoscopic Nd:YAG laser surgery to tracheal stenotic diseases has an instantaneous and definite effect on luminal dilatation and shows significance as a lifesaving procedure. Moreover, the resultant improvement in the patients' general condition could make it possible for them to undergo other combined therapy and prolong their life span. Endoscopic Nd:YAG laser surgery is thus considered to be a very effective and established procedure for the treatment of tracheal stenotic lesions.