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.     

Experimental study of brain lesions after combined coaxial exposure to high-peaked pulse wave form CO2 and Nd: YAG lasers on the brain

The CO2 laser is useful for cutting and vaporization but not for coagulation and hemostasis. On the contrary, YAG laser is effective for coagulation and hemostasis but not for cutting. The purpose of this study is to examine the effect of the exposure of combined, coaxial CO2 and YAG laser on the animal brain to supplement the advantages and draw-backs of each other. To compare these results, each of non-combined pulse wave form CO2 and YAG lasers was employed separately. Materials and Methods: The lasers in this study were pulse wave form CO2 and YAG lasers, employed separately or simultaneously using 130 YZ of Nihon Infrared Industries Company. Japanese white rabbits were anesthetized with pentobarbital. Fronto-parietal burr holes were made, the dura was removed and then Evans blue solution was injected intravenously. The lasers were employed to the cerebral cortex without great vessels using a micromanipulator attached to the operative microscope with a distance of 30 cm. The spot size was 700 mu for CO2 laser and 1200 mu for YAG laser. The first experiment was to see the effect of nine combinations of simultaneous coaxial CO2 of 2, 4 and 8 watts and YAG lasers of 10, 20 and 40 watts, 1 sec on the brain. In the second experiment, also combining two lasers, the exposure time of YAG laser was elongated from 1 or 2 seconds into 2 or 4 seconds and the arrangement of powers was the same as that of the first experiment. The lesions were thus made in 18 different conditions.(ABSTRACT TRUNCATED AT 250 WORDS)     

Experimental study of single and combined coaxial exposure by high-peaked pulse wave CO2 and Nd:YAG laser on the brain: effect on the brain microvasculature in the subacute stage

The effect of single or combined coaxial exposure by Nd: YAG and CO2 (pulse wave) laser on the brain at the subacute stage was examined in experimental animals. Soft X-ray microangiography and histological examination of the brain were performed 48 hours after laser exposure. The lasers in this study were pulse wave form CO2 of 2, 4 and 8 watts and YAG lasers of 10, 20 and 40 watts, employed separately or simultaneously using 130 YZ of Nihon Infrared Industries Company. Japanese white rabbits were anesthetized with pentobarbital. Bilateral fronto-parietal craniectomy were made, and the dura was removed. After intravenous injection of Evans blue, the lasers were employed to the cerebral cortex using a micromanipulator attached to the operation microscope. The spot size was 0.7 mm in diameter for CO2 laser and 1.2 mm for Nd: YAG laser. Forty-eight hours after exposure, microangiography was performed and brains were prepared for the histological examination. Histological examination and microangiogram of the brain after CO2 laser exposure revealed semilunar avascular area in the edematous layer surrounded with dilated vessels. Histological examination and microangiogram of the brain after Nd: YAG laser exposure revealed broad avascular or oligovascular zones in the surrounding edematous tissue, in which the surviving vessels were narrowed. Edematous zones were also shown in the subcortical portion. The histological examination and microangiogram after combined coaxial exposure of CO2 and Nd: YAG lasers revealed triangular avascular or oligovascular zones in the edematous tissue, in which the surviving vessels were narrowed.(ABSTRACT TRUNCATED AT 250 WORDS)     

Endoscopic thoracic sympathectomy: evaluation of pulsatile laser, non-pulsatile laser, and radiofrequency-generated thermocoagulation

We describe a modified technique for percutaneous denervation of the thoracic sympathetic chain by laser to treat selected cases of sympathetic causalgia of the upper extremities. The technique involves transpleural ablation with laser under thoracoscopic guidance through the second or third intercostal space-anterior axillary line. We also compare four different modalities of endoscopic denervation: A xenon chloride excimer laser (308 nm, 35 mJ/pulse, 20 pulses/sec, 2.2 mm catheter tip), CO2 laser (14 W, CW, 2 mm spot size), Nd:YAG laser (88 W, CW, 3 mm spot size), and radiofrequency-generated thermocoagulation (3 W, CW, 2.1 mm catheter tip) by performing bilateral thoracic sympathectomy on 12 mongrel dogs (three dogs each). Criteria analyzed included duration of exposure, power density, total energy output, laser penetration and spread, gross morphology, and scanning electron microscopy (SEM) of the destroyed neural tissue. Total ablation of the inferior segment of the stellate ganglion and the T1-T2 nerve roots by excimer laser required 83 +/1 1 Joules over an exposure period of 118 seconds. Ablation by CO2 and Nd:YAG laser required 153 +/- 13 Joules and 554 +/- 47 Joules delivered over 11 and 6 seconds respectively. In contrast, ablation of the same volume of nerve tissue by RF required 810 +/- 50 Joules over 270 seconds. SEM evaluation revealed that excimer and CO2 laser lesions were narrower in configuration compared to RF and Nd:YAG lesions which showed more lateral spread. The actual depth of penetration per 1 second exposure was similar for Excimer and CO2 (1.5 mm) and RF (1.3 mm), but deeper for Nd:YAG (3 mm).(ABSTRACT TRUNCATED AT 250 WORDS)     

Thermal effects in tissues from combined simultaneous coaxial CO2 and Nd:YAG laser beams.

This study examines the depth of thermal coagulation and charring in swine liver, kidney cortex, tongue (inferior surface), skeletal muscle, inflated lung, and skin resulting from in vivo incision with simultaneous coaxial CO2 and Nd:YAG (1.064 microM) laser beams. At values of 20 w and 40 w, respectively, and at values of 30 w and 60 w, respectively, of combined CO2 and Nd:YAG laser radiation, coagulation depths determined histologically in liver were significantly greater (P less than 0.01) than in the other tissues and were significantly less in inflated lung (P less than 0.05) than in other tissues for the larger laser power settings employed. Coagulation depths achieved at 10 w and 20 w, respectively, and at 20 w and 40 w, respectively, of CO2 and Nd:YAG laser power were comparable to those obtained by other workers in liver and other relatively vascular tissues using a contact Nd:YAG laser tip. Charring depths obtained at power settings of 30 w (CO2) and 60 w (Nd:YAG) were greater in liver (P less than 0.001) than in all other tissues examined. Hemostasis during incision was achieved only for values of the ratio of CO2 to Nd:YAG laser power in the range 2-3 in the more vascular tissues, liver and kidney cortex, whereas hemostasis was achieved also in the lesser vascular tissues at higher values. These results strongly suggest the usefulness of combined simultaneous CO2 and Nd:YAG laser beams in surgery of the more vascular organs and tissues.     

Experimentelle Leber- und Nierenchirurgie mit dem CO2-, CO-, Holmium- und Neodym-Laser

Zusammenfassung Lasergeräte unterschiedlicher Systeme CO₂, CO-, Nd-YAG-und Holmium-YAG-Laser) sind vergleichend mit konventionellen chirurgischen Geräten (Elektroskalpell, Kryoskalpell und Skalpell) an der Leber des Schweines und an der Niere des Hundes eingesetzt worden. CO₂- und CO-Laser verursachten die geringste Gewebeschädigung, gefolgt vom Holmium-Laser; die stärkste Schädigung verursachte der Nd-YAG-Laser. Für die koagulierende Wirkung konnte die umgekehrte Reihenfolge ermittelt werden. Die konventionellen Vergleichsinstrumente zeigten eine schwächere blutstillende Wirkung. Die Reparation der durch Laser erzeugten Schnittflächen verlief über 4 bis 8 Wochen bei Leber und Niere komplikationslos. Reste verkohlten Gewebes waren noch nach 8 Wochen nach der Anwendung bei allen Lasern in unterschiedlicher Menge CO₂

Experimental liver and kidney surgery with CO₂, CO, holmium, and neodym lasersCutting effect, hemostasis, histopathology, and healing

Summary Various laser devices CO₂, CO, Nd: YAG, and holmium: YAG lasers) have been used on pig livers and on dog kidneys for comparison with conventional surgical instruments (electroscalpel, cryoscalpel, and scalpel). CO₂, and CO lasers caused the least tissue damage, followed by the holmium laser; severe damage was caused by the Nd: YAG laser. The order was reverse for coagulative effect. The conventional reference instruments showed a weaker hemostatic effect. Surfaces cut by laser healed in four to eight weeks without complications. Remnants of charred tissue in various quantities could still be detected after eight weeks in all cases where CO₂, CO, and Nd: YAG lasers had been used. This obviously did not affect scar formation.

Die Untersuchungen wurden mit Unterstützung des BMFT durchgeführt     

Vasovasostomy in the murine vas deferens: comparison of the Nd:YAG laser at 1.06 microns and 1.318 microns to the CO2 laser

A comparison is made of laser anastomoses of the murine vas deferens at different energies with the neodymium (Nd):YAG laser at 1.06 micron and 1.318 micron and with the CO2 laser. A total of 28 welds were performed with a free-hand technique employing a 600-micron silicon fiber with the Nd:YAG and a hand piece with a 500-micron spot size for the CO2. After 6 weeks, all animals were sacrificed and the vasa evaluated for patency. Fifteen out of 28 controls repaired with microsurgical techniques were found to be patent; 4/10 vasa were patent with use of the Nd:YAG at 1.318 micron at laser energies of 300 mW and 500 mW. At 1.06 micron, only 1/4 anastomoses was patent at a power setting of 1 W. None of the anastomoses performed with the CO2 laser was patent. Histologic study revealed intense fibrosis in all the lasered vasa, with sperm granuloma formation associated with most anastomoses. Although this is a preliminary study, it appears that the Nd:YAG laser at 1.318 micron and a power setting of 300-500 mW provides patency rates superior to the Nd:YAG at 1.06 micron and to the CO2 lasers and is equivalent to standard micro-surgical techniques in the murine vas deferens.     

New long-wavelength Nd:YAG laser at 1.44 micron: effect on brain

A wavelength-shifted Nd:YAG laser, tuned to coincide with the infrared absorption peak of water at 1.44 microns, was used to make lesions in normal rabbit brain. A total of 48 lesions were made with power up to 20 W, with energy up to 40 joules, and with two different spot sizes. These lesions were compared to lesions made with 1.06 microns radiation from an Nd:YAG laser under identical operating conditions. Measurements of blood-brain barrier damage and width, depth, and volume of tissue affected were obtained 30 minutes after placement of the lesions. It was found that 1.44-microns lesions produced photoevaporative tissue loss at the highest intensities used. The layer of coagulated tissue remaining after photovaporization had a mean thickness of 0.6 mm irrespective of the volume of tissue removed. There was no photovaporization in the 1.06-microns lesions. In addition, the amount of peripheral edema per unit volume of tissue coagulated was approximately half at the 1.44-microns wavelength. These findings suggest that the 1.44-microns Nd:YAG laser may be a useful surgical instrument since it combines the photoevaporative effect of the CO2 laser while maintaining the advantages of the conventional Nd:YAG laser (quartz fiber delivery and effective hemostasis).     

The potentials of CO2 laser in the surgery of the liver, biliary tract and pancreas.

The Nd:YAG and CO2 laser can be used with benefit in the surgery of the liver, biliary tract and pancreas. The Nd:YAG laser is most suitable for cutting parenchymatous organs, as e.g. the liver. In biliary surgery the CO2 laser can be recommended. Based on their 12 cases, authors discuss the applicability of CO2 laser.     

Effects of Nd:YAG and CO2 lasers on cerebral microvasculature. Study in normal rabbit brain

The effect of Nd:YAG and CO2 laser beams on cerebral microvasculature was examined in experimental animals. Soft x-ray microangiography and histological examination of the brain after Nd:YAG laser exposure revealed broad avascular or oligovascular zones in the irradiated and the surrounding edematous tissue, in which the surviving vessels were narrowed and tapered without significant leakage of blood. After CO2 laser exposure, a wedge-shaped tissue defect surrounded by layers of charring, coagulation, and edema was observed. The main finding in the surrounding coagulation and edematous layers was dilatation of the vessels. Hemorrhage was sometimes observed, mainly in the edematous layer. These findings seem to explain the effective hemostatic capability of the Nd:YAG laser and the occasional hemorrhage following CO2 laser exposure, especially at high energy output.     

Application of pulsed and continuous wave 1.32 and 1.06 microns wavelengths of the Nd:YAG laser in the canine tracheobronchial tree: a comparative study

Previous investigations have shown good clinical potential for the use of the 1.32 microns wavelength Nd:YAG laser because its soft tissue absorption is better than that of the 1.06 microns wavelength Nd:YAG laser. The 1.32 microns wavelength Nd:YAG laser has an absorption coefficient in water that is 10 times higher than the 1.06 microns wavelength Nd:YAG laser. A comparative in vivo study of laser soft tissue effects was performed by using the 1.32 microns wavelength and the 1.06 microns wavelength Nd:YAG lasers in a pulsed wave (PW) mode and continuous wave (CW) mode using a non-contact endoscopic delivery system. A standard 5 mm mucosal lesion was made in the canine tracheobronchial tree down to the level of the perichondrium. Soft tissue and cartilage effects were examined by light and scanning electron microscopy, acutely, 1 week and 2 weeks after operation, and a comparison was made between the different laser modalities. To create similar lesions, higher energy was required when using the 1.06 microns wavelength Nd:YAG laser. Soft tissue injury was greater with the 1.06 microns wavelength in CW mode, and no cartilage damage occurred in the PW mode. Soft tissue and cartilage repair after 1 and 2 weeks was better with the 1.32 microns wavelength laser. In comparison, the CO2 laser and the contact Nd:YAG laser proved to be more precise cutting tools than the 1.32 microns wavelength or the 1.06 microns wavelength Nd:YAG lasers. Both Nd:YAG laser wavelengths were useful for coagulation and vaporization of tissues and blood vessels. More studies are needed to determine the effect of the new 1.32 microns wavelengths on endotracheal tumors.     

Influence of Nd:YAG laser power density and coaxial CO2 on the gastric wall

A detailed understanding is required of the effect of Nd:YAG power density and coaxial CO2 on tissue necrosis in both the acute and healing situation. Lesions were produced by varying peak powers at eight increments of 10 W from 40-110 W/sec for a time duration of 1 sec with and without coaxial CO2 on the rabbit (n = 16) stomach. Surface areas and careful histological examinations were performed at 2 hr and 4 days. In further experiments, a total incident energy of 60 or 120 J with varying peak powers from 30-120 W/sec were applied at a 1-cm distance. The lesion surface area at 1 cm was 21.7 mm2 compared to 12 mm2 when the fiber tip was held 2 cm away (p less than 0.05). Coaxial CO2 at 1 cm reduced the surface area to 10 mm2 (p less than 0.001). There was a positive correlation between surface areas and the incidental power (r = 0.86, p less than 0.01). There was no significant difference in the mean surface area of lesions at 2 hr compared to those at 4 days, nor was there a correlation between the increasing peak powers with the constant incident energy. Histological features were those of coagulative necrosis (81%) with minimal ulceration (1.6%) at 2 hr with ulceration increasing to 22% at 4 days. These results have helped in planning a safe and effective Nd:YAG photocoagulation study in patients in order to obtain maximum hemostasis with minimal tissue injury.     

Treatment of cutaneous and deep vascular lesions with the Nd:YAG laser

This study intends to document and evaluate the first compiled experience in the treatment of both cutaneous and deep vascular lesions using the Nd:YAG laser. Thirty-eight patients were treated over a 5-year period from 1979 to 1984 using the Nd:YAG laser with FDA approval. Lesions included capillary, cavernous, combined capillary-cavernous hemangiomas, portwine stains, arteriovenous malformations, lymphangiomas, multiple telangiectasias, and one case of Klippel-Trenaunay-Webber syndrome. The number of treatments per patient ranged from one to four. Partial or complete resolution of these various lesions, as evidenced by a decrease in size, and/or normalization of pathologic cutaneous changes was noted in a majority of patients. While both the argon and CO2 lasers have been well studied in the treatment of cutaneous vascular lesions, this is the first compiled series reporting results using the Nd:YAG for such problems. The Nd:YAG laser represents an alternative modality in the treatment of cutaneous hemangiomas and introduces an efficacious method in the treatment of cavernous vascular lesions.     

Ab-interno neodymium:YAG versus erbium:YAG laser sclerostomies in a rabbit model.

This study was undertaken to determine whether thermally-induced tissue necrosis was a factor in ab-interno contact-laser sclerostomy failure. A rabbit model was used to compare the continuous-wave Neodymium (Nd):YAG with the pulsed Erbium (Er):YAG laser with respect to such failure. Laser energy was focused into a fused-silica fiber optic (400 microns) for the Nd:YAG laser (12 W; 3 to 5 seconds), and into a single-crystal, uncladded sapphire fiber optic (250 microns) for the Er:YAG laser (7 to 8 mJ; 250 microseconds; 6 to 8 pulses). The Nd:YAG and Er:YAG lasers required from 21 to 35 J and from 42 to 64 mJ, respectively, to create the sclerostomies. Filtering blebs and intraocular pressure reduction lasted longer (log-rank test; P less than .03) and surgical complications were fewer in the Er:YAG group than in the Nd:YAG group. By creating sclerostomies with minimal thermal damage, the Er:YAG laser may offer significant clinical advantages over lasers producing larger thermal effects.     

Comparison of surgical lasers and conventional methods in skin incisions

Steel scalpel, electrocautery, CO2 laser used in a continuous wave mode (CW) and rapid superpulse mode (RSP), and contact Nd: YAG laser were tested on pig skin incisions. Speed of incision and histological changes near the wounds were examined. Light microscopical observations were made on postoperative day 0 using standard Van Gieson stain. Width of the scar on postoperative day 14 was also measured. Steel scalpel produced the least pathological changes in the skin, followed by RSP. Electrocautery did not differ significantly from the CO2 lasers in this respect on postoperative day 0. The damage was larger after contact Nd:YAG laser. The situation was essentially similar on postoperative day 14. The width of the scar was narrowest after steel scalpel and widest after contact Nd:YAG laser (p less than 0.01; Nd:YAG vs. other methods). Electrocautery and the two CO2 lasers produced equal scarring. However, electrocautery was significantly faster than any of the lasers (p less than 0.001).     

Effect of simulated CO2 and GaAlAs laser surface decontamination on temperature changes in Ti-plasma sprayed dental implants

BACKGROUND AND OBJECTIVE: To investigate and compare temperature elevations at the implant-bone interface during simulated implant surface decontamination with a CO2 and a GaAlAs laser. STUDY DESIGN/MATERIALS AND METHODS: Stepped cylinder implants (Frialit 2) Friadent GmbH, Mannheim, Germany) with a Titanium plasma sprayed surface were inserted into bone blocks cut from pig femurs. An artificial periimplant bone defect provided access for laser irradiation in the coronal third. Both lasers were operated at 1.0-2.5 W in the cw-mode. The bone block was placed into a 37 degrees C water bath in order to simulate in vivo thermal conductivity and diffusitivity of heat. K-type thermocouples connected to a digital meter were used to register temperature changes at the periimplant bone. RESULTS: In mean, the critical threshold of 47 degrees C was exceeded after 8 seconds at a power output of 2.5 W, 13 seconds at 2.0 W, 18 seconds at 1.5 W, and 42 seconds at 1.0 W with the GaAlAs laser and 15 seconds (2.5 W), 23 seconds (2.0 W), 35 seconds (1.5 W), and 56 seconds (1.0 W) with the CO2 laser. At equal energy fluence, GaAlAs laser irradiation induced significantly higher temperature elevations than CO2 laser irradiation. CONCLUSIONS: In an energy dependent manner implant surface decontamination with both laser types must be limited in time to allow the implant and bone to cool down. Clinical guidelines are presented to avoid tissue damage.     

An experimental study of the effects of electrocautery and various lasers on gastrointestinal tissue

It is possible that in the future, lasers will replace electrocautery in gastrointestinal surgical procedures. Few studies exist that compare the tissue effects of electrocautery with newer laser modalities. In this study, the tissue effects of electrocautery, noncontact Nd:YAG, contact Nd:YAG, and CO2 lasers were studied in the stomach, small bowel, colon, liver, and pancreas in 24 rats. At light microscopic examination, all tissue damage was thermal in nature, irrespective of the modality used. Furthermore, an independent observer was unable to distinguish which method has been used in most tissues. Tissue effects were similar in the stomach, small intestine, and colon after use of all the modalities. The CO2 laser caused slightly less damage than the other methods (p less than 0.05), but with use of this modality, hemostasis could not be achieved in the liver and pancreas. The contact Nd:YAG laser caused moderate damage with excellent hemostasis in all tissue. The noncontact Nd:YAG caused significantly more tissue damage than all other methods (p less than 0.01), especially in the liver and pancreas. The results suggest that the new contact laser system provides an effective method of performing gastrointestinal surgery with especially good hemostatic effects on liver and pancreatic resections.     

三种红外波长激光治疗面部草莓状血管瘤的疗效

目的对比观察3种红外波长激光治疗小儿面部草莓状血管瘤（strawberry hemangiogila．SH）的疗效及容貌结果。方法5～12岁面部SH患儿300例．随机分为半导体激光组,Nd：YAG激光组和CO2激光组,每组100例。3组治疗参数相同（功率10W、光斑直径0．2cm、功率密度318W／cm2）,根据皮损面积大小,半导体激光组和Nd：YAG激光组分别行非接触式扫描凝固术．CO2激光组行气化术。治疗后6个月复查评定疗效及容貌结果。结果治愈率半导体激光组89％,Nd：YAG激光组83％。CO2激光组69％（P〈0．05）;容貌优良率CO2激光组87．0％,半导体激光组86．5％,Nd：YAG激光组57．8％（P〈0．01）;平均治疗次数、治疗时间和治疗中出血量半导体激光组均少于Nd：YAG激光组和CO2激光组（P〈0．01）。结论波长830nm的半导体激光（功率密度318W／cm2）,治疗小儿面部SH具有1次治愈率高、治疗时间短、治疗中出血少和容貌结果好等优点,为治疗小儿面部SH的首选方法。     

Safe pleural contraction employing a new tip for electrosurgical units. An ex vivo experiment.

BACKGROUND: Certain pulmonary lesions are treated by lung tissue contraction induced by heat administered by laser or electrosurgical unit (ES). ESs are comparatively less expensive, less complicated and more ubiquitous than a lasers but with their conventional tip carries the a risk of damaging the pleura. We developed a large ball tip (M-tip) for ES and evaluated its effect on the pleura in comparison with that of Nd:YAG laser in ex vivo lung. METHOD: We employed lobes obtained through surgical resection. Using the Nd:YAG laser, the lung was irradiated for 2 seconds at levels of 5, 10 and 20 watts (10, 20 and 40 Joules). Using the M-tip ES, the pleura received treatment at levels of 10, 20 and 40 watts for 2 seconds (20, 40 and 80 Joules) in spray coagulation mode. Upon completion of these procedures, 144 tissue specimens obtained from 24 lobes were examined under light microscopy. RESULTS: Upon the application of Nd:YAG at 20 Joules, 22 (92%) of 24 visceral pleura demonstrated amorphous degeneration. With the application of ES at 40 Joules watts, 24 (100%) samples examined demonstrated amorphous degeneration (P = 0.47). Of the samples where pleural destruction was evident (Nd:YAG; 40 Joules, ES; 80 Joules), an accompanying air leak pattern (pleural destruction associated with slight parenchymal contraction) was observed in 5 (21%) of the samples treated with Nd:YAG and in 10 (42%) of those treated with the M-tip ES (p = 0.12). CONCLUSION: The M-tip ES induced proper contraction of the pleura with relatively little destructive damage to the pleura at 40 Joules. Accordingly, it may be possible to induce pleural contraction using this new device with the same degree of safely that the Nd:YAG laser provides.     

The treatment of cutaneous vascular lesions with the Nd:YAG laser

The Nd:YAG laser is well suited for the treatment of cutaneous vascular lesions. The characteristic properties of the Nd:YAG laser emissions in tissue are a high degree of penetration with low absorption by unpigmented tissue. The result is a coagulative effect on tissue containing hemoglobin with relative skin sparing. The Nd:YAG laser was used to treat 116 patients with a variety of cutaneous vascular lesions. Good to excellent results were obtained with a low complication rate for deep cavernous and capillary lesions, port wine stains, and minor vascular ectasias above the lower extremities. Minor venous ectasias and varicosities located on the lower extremities responded poorly. The Nd:YAG laser represents an efficacious tool for the treatment of difficult vascular lesions, with the exception of venous lesions of the lower extremities.