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At least 433 records · Page 24Linked to original sources
PubMed1994

Nd-YAG laser pleurodesis via thoracoscopy. Endoscopic therapy in spontaneous pneumothorax Nd-YAG laser pleurodesis.

From January 1986 to February 1993, 85 patients with spontaneous pneumothorax were treated in our department by a new endoscopic procedure using an Nd-YAG laser beam via thoracoscopy to obtain permanent pleurodesis and to treat the lung lesion responsible for the air leak. The 55 men and 30 women ranged in age from 16 to 51 years (mean age 26 years). Under general anesthesia the thoracoscope was introduced through a 1-cm incision in the anterior axillary line of the fourth intercostal space. In 68 patients small blebs (less than 2 cm in diameter) were detected and successfully resected with low power Nd-YAG laser pulses. In two patients found at thoracoscopy to have lesions larger than 2 cm, the Nd-YAG laser failed to seal the air leak and thoracotomy was performed. Air leaks were not detected at endoscopy in the remaining patients. After treatment of the lung lesions, the parietal pleura was abraded by using the laser energy. There were no side effects. Eighty patients were treated successfully without recurrence (maximum follow-up 86 months). Three other patients developed recurrence of pneumothorax after 5, 6, and 24 weeks, and surgery was considered mandatory in 2 of them. At thoracotomy, in both patients, a small bleb was detected in the lower lobe and resected. The whole upper lobe was strongly adherent to the parietal pleura in the site of previous laser abrasion. The authors conclude that Nd-YAG laser via thoracoscopy should be considered as a viable therapeutic option in patients with spontaneous pneumothorax.

Adolescent↗
PubMedDate not supplied

Comparison of laser in situ keratomileusis outcomes with the Nidek EC-5000 and LSX LaserSight excimer lasers.

PURPOSE: To report the results of laser in situ keratomileusis (LASIK) for myopia with and without astigmatism using the Nidek EC-5000 and LaserSight LSX excimer laser systems. METHODS: A retrospective analysis of refractive outcomes with each laser was conducted. Approximately 2,900 myopic and astigmatic treatments up to -10.00 D (spherical equivalent refraction) were analyzed using refractive outcomes analysis software. RESULTS: At 6 months postoperatively, 78% of patients treated with the Nidek EC-5000 laser and 53% of patients treated with the LaserSight LSX laser were within +/-0.50 D of the intended correction. CONCLUSION: A difference in safety, stability, and efficacy of LASIK was found that favored the Nidek EC-5000 excimer laser.

Adolescent↗
PubMedDate not supplied

Effects of laser plume evacuation on laser in situ keratomileusis outcomes.

PURPOSE: To study the effects laser plume evacuation on LASIK outcomes using a surgical vacuum and the Nidek EC-5000 excimer laser. METHODS: Three-month LASIK postoperative data were evaluated retrospectively for 117 eyes treated with a laser plume evacuator and 82 eyes treated without a laser plume evacuator. All eyes were treated with the same Moria CB microkeratome and the same Nidek-EC 5000 excimer laser using the same nomogram. RESULTS: No statistically significant difference was noted in the frequency of corneal abrasions, flap slippage, or the level of postoperative interface debris. A statistically significant difference (P < .001) was noted in postoperative residual refractive error and uncorrected visual acuity. In the group treated without a plume evacuator, 65% (n = 53) were within +/- 0.50 D of the intended correction, 59% (n = 48) had an uncorrected visual acuity of 20/20 or better, 68% (n = 56) had an uncorrected visual acuity of 20/25 or better, and 90% (n = 73) had an uncorrected visual acuity of 20/40 or better. In the group treated with a plume evacuator, 92% (n = 108) were within +/- 0.50 D of the intended correction, 74% (n = 87) had an uncorrected visual acuity of 20/20 or better, 89% (n = 104) had an uncorrected visual acuity of 20/25 or better, and 96% (n = 112) had an uncorrected visual acuity of 20/40 or better. CONCLUSION: Laser plume evacuation using surgical tubing and a surgical vacuum improved refractive and uncorrected visual acuity outcomes following LASIK.

Astigmatism↗
PubMed1997

[An experimental study of laser treatment using two different type of neodymium:YAG laser on transplanted tumor in Scid mice].

BACKGROUND: We report basic animal experimental study which was evaluated the thermocoagulation effects of two different type of Nd:YAG laser (pulse and continuous wave (CW) laser). METHODS: The Rotalase internally reflecting fiber delivery system coupled to the pulse and CW Nd:YAG laser was used to create lesions in Seminoma tissue implanted Scid mice with the fiber tip 2 mm away from the target tissue under the water. Laser power output used was 20, 40 and 60-watt for varying times (30-180 sec) of irradiation. Stationary lesions, where a single spot of target was irradiated, were created. On the other hand, we measured tissue temperatures at 7, 10 and 14 mm from tissue surface. The seminoma tissues removed from Scid mice were photographed after bisection, the fixed in 10% formalin and examined histologically. RESULTS: For the purpose of these experiments, ablated tissue is defined as the volume of tissue that has been destroyed by both coagulation and vaporization. Estimates of the volume of ablated tissue were made by macroscopic examination of the bisected lesion, measuring the depth and width of the lesion as seen from the edges of the coagulated area around vaporized zone. The mean depth and width penetration, volume ablation and rising of the tissue temperature at pulsed 60-watt, 60 seconds was greater than that observed at other groups. Irradiated spot lesions were characterized by an initial 10-20 second period of tissue blanching followed by an audible "popcorn phenomenon" which meant more than 100 degrees C in tissue temperature, then formation of small surface bubbles as tissue began to evaporate and char. CONCLUSION: This study suggests the potential usefulness of the pulse Nd:YAG laser for Visual Laser Ablation of the Prostate (VLAP).

Animals↗
PubMed1997

[Argon laser peripheral iridoplasty and laser iridectomy for plateau iris glaucoma].

OBJECTIVE: To evaluate the therapeutic effects of a combined laser technique for plateau iris glaucoma. METHODS: 20 cases (37 eyes) of early plateau iris glaucoma were treated by a laser technique that included argon laser peripheral iridoplasty and argon + Nd:YAG laser iridectomy. RESULTS: The postoperative follow-up ranged from 8 months to 4 years and 7 months (30 eyes for more than 2 years, mean 2.7 years). 17 cases (32 eyes) obtained satisfactory effects, no acute-attacks were seen in the follow-up, intraocular pressure decreased from 5.8 +/- 1.04 kPa to below 2.74 kPa, peripheral anterior chamber depth increased, angle widened, the iris retracted away from the trabecular meshwork, thus further synechiae of chamber angle were prevented effectively, and the dark room provocative test results turned to negative in 86.7% of cases. CONCLUSION: Argon laser peripheral iridoplasty combined argon + Nd:YAG laser iridectomy may be a safe and effective method for treatment of plateau iris glaucoma.

Adult↗
PubMedDate not supplied

Laser trabeculodissection with a photopolishing scanning excimer laser.

A phase I study of nonpenetrating trabeculectomy (Zimmerman procedure) using a scanning excimer laser system was conducted to evaluate the ability of this laser system to achieve the deep dissection required to allow significant filtration without inadvertent penetration into the anterior chamber. A photopolishing, scanning 193 nm excimer laser system (LS 2000, LaserSight, Inc.) was used with a proprietary fluence, spot size, scanning pattern, and ablation shape to perform a trabeculodissection under a scleral flap with a limbal-based conjunctival flap in 8 cases of advanced glaucoma including 5 eyes that had a failed trabeculectomy. The laser trabeculodissection (LTD) was carried through Schlemm's canal and the juxtacanalicular trabecular meshwork, achieving vigorous aqueous outflow. No peripheral iridectomy was done. The scleral flap was closed loosely with a 10-0 suture. Mitomycin-C was used intraoperatively. In no case did inadvertent penetration into the anterior chamber occur. No peripheral iridectomy was performed. No intraoperative hyphema occurred. There was no postoperative iritis except minimal anterior chamber reaction in 1 eye with preoperative rubeosis. Postoperatively, a good filtering bleb was achieved in all 8 eyes with substantial reduction in the intraocular pressure without topical antiglaucoma therapy. No cases of postoperative shallowing (overfiltration) occurred. Gonioscopy, postoperatively, revealed no new peripheral anterior synechiae (PAS) to the filtration site and an intact inner trabecular meshwork. All eyes were followed for a minimum of 6 months. In this phase I study, laser trabeculodissection (LTD) with a 193 nm photopolishing, scanning system appears to be a promising alternative to full-thickness trabeculectomy, achieving significant filtration while perhaps avoiding much of the risk of filtration surgery. The laser system seemed to provide a more reliable, better-controlled dissection than a knife. The aqueous drainage seems to have acted as a self-regulating endpoint by absorbing UV energy, thus avoiding inadvertent penetration into the anterior chamber. More study is needed to establish the appropriate role of LTD in glaucoma therapy.

Chronic Disease↗
PubMed1999

Treatment of dental root fracture by medium energy CO2 laser and DP-bioactive glass paste. Part. II: Compositional, structure, and phase changes of DP-bioglass paste after exposed to CO2 laser.

Fractured teeth are difficult to treat effectively. Currently, such as root fractures are usually treated by full-coverage restoration, root amputation, or tooth extraction. If the fusion of tooth fracture by laser were possible, it could offer a different therapy to repair fracture teeth. We tried to use a developed DP-bioactive glass paste to fuse or bridge the tooth crack line by a medium energy continuous-wave CO2 laser. The present report was focused on the phase transformation and rescrystallization of DP-bioactive paste during expose to the CO2 laser. The materials will examine by means of XRD, FTIR, DTA/TGA, and SEM. From the study, we could expect that the temperature increase due to laser irradiation must be over than 900 degrees C and the DP-bioactive glass paste could be melted in a short period of time after irradiation. In the study, we successfully developed a DP-bioactive glass paste which could form a melting glass within minutes after exposed to a medium energy density continuous-wave CO2 laser. The paste will be used to bridge the enamel or dentine surface crack by the continuous-wave CO2 laser in the near future.

Dental Cements↗
PubMed1990

Lasers in dentistry: new possibilities with advancing laser technology?

Although there are a considerable number of published papers on the role of laser treatment in dentistry, a critical review shows that laser technology is used only by specialists in a small therapeutic field. Most lasers are heat-producing devices converting electromagnetic energy into thermal energy. These lasers find uses in oral surgery for cutting or coagulating soft tissues or in the welding of dental prostheses. More recently, new types of lasers have offered non-thermal modes of tissue interaction, called photoablation, photodisruption and photochemical effects. Basic and clinical research is being carried out into the application of these devices in dentistry. However, much development will be required before lasers can replace conventional surgical methods for treating oral cancer or indeed replace the conventional bur for excavating carious lesions.

Dentistry↗
PubMed1990

The contact neodymium-yttrium aluminum garnet laser. A new approach to arthroscopic laser surgery.

Arthroscopic treatment of meniscal lesions has been modified as technological advances have occurred. However, alternatives to conventional arthroscopic cutting tools, including electrocautery and CO2 lasers, have thus far met with limited success. The recent development of a sapphire tip has enabled the use of the neodymium-yttrium aluminum garnet (Nd-YAG) laser in a contact mode in a saline medium. This study compares the biology of the Nd-YAG laser to that of electrocautery and scalpel techniques with respect to its effects on articular cartilage and the meniscus. The contact Nd-YAG laser has advantages over both scalpel and electrocautery with regard to its effects on articular cartilage. It also has significant biologic advantages over electrocautery for meniscal lesions. Although in its infancy in the clinical setting, the contact Nd-YAG laser represents the possible beginning of a new era for application of laser energy in arthroscopy.

Aluminum↗
PubMed1989

Mid-infrared lasers for endoscopic surgery. A new class of surgical lasers.

Unlike the Nd:YAG, the CO2 laser produces well circumscribed tissue removal with little unwanted damage because of its high absorption coefficient relative to tissue water. Unfortunately, conventional quartz fibers cannot transmit wavelengths greater than three microns, well below the ten micron wavelength of the CO2 laser. Thus, fiberoptic transmission of CO2 laser requires use of exotic materials that lack the excellent properties of quartz fibers and that, in some cases, are toxic or chemically unstable. However, there are large peaks in the infrared absorption curve of water in the two to three micron region. Lasers that operate in this mid-infrared region should permit CO2-like precision of cutting, along with excellent transmission through quartz fiberoptics. Two mid-infrared lasers with a fiberoptic delivery system, the Er:YAG (2.94 micron) and the Tm-Ho-Cr:YAG (2.15 micron) have been evaluated with human colon tissue in vitro and with rabbit gastric tissue in vivo. Histologic sections reveal excellently well localized lesions with minimal underlying thermal damage. Depth of penetration is controllable and occurs in very small increments. There is little spreading of the lesions at the 24 hour mark resulting from secondary thermal damage. Based on these facts, the authors think that these lasers will be of benefit to endoscopic surgeons.

Animals↗
PubMed1986

Microvascular anastomosis with a low-output carbon dioxide (CO2) laser. I. Laser device, techniques and conditions of anastomosis.

A low-output carbon dioxide laser was tentatively fabricated and applied to facilitate microvascular anastomosis. The femoral arteries and veins of Wistar albino rats were end-to-end anastomosed by either irradiating with a CO2 laser or the conventional technique of manual suturing. The CO2 laser was used at a power level of 21-40 mW and an exposure time of 5-15 sec. The patency rate was 96.2% for arteries and 92.6% for veins with the laser technique, while it was 97.6% for arteries and 78.0% for veins with the conventional technique. There was no significant difference between these two techniques in the patency rate of arteries, however, veins showed a significantly higher rate with the laser technique than with the conventional technique. The main advantages of the laser technique are that it is easier to perform and less time-consuming than the conventional technique of manual suturing.

Animals↗
PubMed1988

[A laser surgery procedure in the treatment of tattooing with the argon ion laser].

A laser surgery procedure for treating tattoos using argon ion laser is described. The epithelial changes during continuous radiation are land marks for laser surgery procedure: 1. The coagulation zone, 2. its bubble-like rise, 3. its breaking, 4. the beginning of the carbonisation zone and 5. setting of a decreasing coagulation zone for smoothing the edges. From the very onset of the carbonisation zone radiation is discontinued and continued only in the periphery producing a decreasing coagulation zone. Punctiform and line-pattern laser application is employed; the untreated areas in between are treated in the following session. The average time between the sessions is 7 weeks and the average number of sessions for a tattoo is 3.1. The observation time is on an average 2 years and 1 month. 134 tattoos of 43 patients are treated by this technique. In 18.6% of the tattoos very good results are achieved, in 51.5% a good result, in 28.4% a satisfactory result and in 1.5% an unsatisfactory result. Hypopigmentations are seen in 19.4%, atrophic scars in 12.7%, hypertrophic scars in 14.9% and a rest of tattoos in 8.9%. Keloids are not seen. Using this argon laser technique for treating tattoos you will obtain better results with fewer side effects than in those studies which are accomplished treating tattoos with argon lasers and described in literature up to now.

Adolescent↗
PubMed1995

Histopathological evaluation of laser thermocoagulation in the human prostate: optimization of laser irradiation for benign prostatic hyperplasia.

We have previously shown in a canine prostate model that a noncontact low power neodymium:YAG laser regimen of 15 watts for 180 seconds yields a larger volume of coagulation necrosis than the currently recommended high power regimen of 50 watts for 60 seconds. These 2 regimens have not yet been compared in humans. The objective of this study was to evaluate histopathologically the thermocoagulation effect of these 2 laser regimens in the human prostate and the effect of the spatial distribution of the laser lesions on the extent of coagulation necrosis. The study was conducted in 10 patients undergoing radical prostatectomy or cystoprostatectomy. The laser treatment was given transurethrally 1 hour before removal of the specimen. There were no fractures of the prostate. The coagulation necrosis did not reach the peripheral zone and it was minimal in areas rich in fibromuscular tissue, such as the bladder neck. At times, nodular benign prostatic hyperplasia was unaffected. A 4-quadrant treatment in the same plane often yielded small nonconfluent lesions. Confluent lesions in the same plane yielded approximately 30% greater depth of coagulation necrosis, which was achieved when 3 or 4 lesions were created on each side of the prostate (per single transverse plane). Likewise, coagulation necrosis observed with 15 watts for 180 seconds was approximately 40% greater than that noted with the 50 watts for 60 seconds regimen. Our findings suggest that noncontact laser prostatectomy is a safe procedure that can be improved by modifying the laser regimen and the spatial distribution of lesions.

Aged↗
PubMed1996

[The ruby laser: can removal of pigmented skin changes with the ruby laser be done by non-physician personnel?].

Chromophores of the skin, especially melanin and exogenous pigments (e.g., tattoos), absorb red ruby laser light (694 nm) comparatively well. Selective photothermolysis of melanin, melanosomes, and tattoo particles theoretically leads to clearing or removing of cutaneous pigmented lesions and tattoos. The excellent cosmetic results after ruby laser treatment are leading to the increasingly widespread use of these costly laser systems. Not only physicians, but also cosmeticians and masseurs work with ruby lasers to remove tattoos and cutaneous pigmented lesions, often without correct dermatological diagnosis. An ever-increasing number of patients present themselves at our department with nevi previously treated with ruby laser. The dimensions and potential sequelae of these treatments are still unknown. Therefore, we present the principles of ruby laser treatment and its indications, side effects, and the main risks.

Humans↗
PubMed2006

The role of laser fluence in cell viability, proliferation, and membrane integrity of wounded human skin fibroblasts following helium-neon laser irradiation.

BACKGROUND: In medicine, lasers have been used predominantly for applications, which are broadly termed low level laser therapy (LLLT), phototherapy or photobiomodulation. This study aimed to establish cellular responses to Helium-Neon (632.8 nm) laser irradiation using different laser fluences (0.5, 2.5, 5, 10, and 16 J/cm(2)) with a single exposure on 2 consecutive days on normal and wounded human skin fibroblasts. MATERIALS AND METHODS: Changes in normal and wounded fibroblast cell morphology were evaluated by light microscopy. Changes following laser irradiation were evaluated by assessing the mitochondrial activity using adenosine triphosphate (ATP) luminescence, cell proliferation using neutral red and an alkaline phosphatase (ALP) activity assay, membrane integrity using lactate dehydrogenase (LDH), and percentage cytotoxicity and DNA damage using the Comet assay. RESULTS: Morphologically, wounded cells exposed to 5 J/cm(2) migrate rapidly across the wound margin indicating a stimulatory or positive influence of phototherapy. A dose of 5 J/cm(2) has a stimulatory influence on wounded fibroblasts with an increase in cell proliferation and cell viability without adversely increasing the amount of cellular and molecular damage. Higher doses (10 and 16 J/cm(2)) were characterized by a decrease in cell viability and cell proliferation with a significant amount of damage to the cell membrane and DNA. CONCLUSIONS: Results show that 5 J/cm(2) stimulates mitochondrial activity, which leads to normalization of cell function and ultimately stimulates cell proliferation and migration of wounded fibroblasts to accelerate wound closure. Laser irradiation can modify cellular processes in a dose or fluence (J/cm(2)) dependent manner.

Cell Proliferation↗