bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intravascular ultrasound guided Holmium:YAG laser recanalization of occluded arteries
Authors: White Rodney A. , Kopchok George E. , Tabbara Marwan R. , Cavaye Douglas M. , Cormier Francois 
Published: March 2007

AbstractCurrent angioplasty devices are limited by arterial wall dissection and perforation, and by early recurrence from inadequate debulking of lesions. This study evaluated intravascular ultrasound (IVUS) as guidance for concentric laser recanalization of arterial occlusions. Twelve, 2–4‐cm‐long canine iliac artery occlusions were treated at 2 weeks (organizing thrombus) to 12 weeks (firm fibrous lesions) using a Holmium:YAG laser (2,100 nm wavelength) in free running mode, FRM, (250 μsec pulse, 5 Hz), n = 9; and Q‐switched mode, QSM (200 ns pulse, 6 Hz), n = 3. A 200 μm (n = 2) or 600 μm (n=10) optic fiber was centered in the artery coaxial to a 5Fr rotating A scan IVUS probe. The fiber was positioned in the center of the artery distal to the lesion and slowly advanced through the obstruction. In 8 occlusions the same fiber was used as a guide wire for passage of either a 1.6‐mm‐(n=2) and/or 3.0‐mm (n=6) diameter multifiber catheter (19 × 100 and 19 × 200 μm fibers, respectively) using FRM energy to further debulk the lesion. In all cases, IVUS guidance enabled concentric initial recanalization of occlusions, although 3 vessel perforations resulted from fiber deviation off the center of the lumen at a distance of 2 to 4 cm from the IVUS imaging element. Both QSM and FRM modes ablated tissue, with FRM modes producing more tissue fragmentation and thermal effect. IVUS images accurately diagnosed the location of lesions compared to angioscopic views and pathologic analysis of the specimens. This study suggests that IVUS guided laser energy may enable initial concentric re‐canalization of arterial occlusions if adequate tissue removal can be accomplished to provide continuous IVUS imaging as the re‐canalization proceeds. © 1992 Wiley‐Liss, Inc.
Laser treatment of premalignant and malignant squamous cell lesions of the penis
Authors: Malek Reza S. 
Published: March 2007

AbstractThirty men with biopsy‐proven premalignant or malignant squamous cell lesions of the penis were treated. All had subclinical aceto‐white lesions with histologic evidence for human papilloma virus infection. Nineteen patients had penile intraepithelial neoplasia (PIN I and II) and 11 had squamous cell carcinoma. Of these 11 patients, 6 had noninvasive penile intraepithelial neoplasia—carcinoma in situ (PIN III/Tis)—and 5 had invasive squamous cell carcinoma (4 stage T2 and 1 T3). All were treated with laser: CO2 was used for low‐stage lesions, Nd:YAG was used alone or in combination with CO2 laser for more histologically advanced lesions, and KTP/532 was used in one patient with squamous cell carcinoma (Tis). Follow‐up in 23 patients for up to 2 years showed that all but 1 (stage T3) remained free from penile malignancy. Appropriate laser therapy for all but deeply invasive (T3) tumors controls local disease, producing results that are clinically equal and cosmetically and functionally far superior to partial penectomy. © 1992 Wiley‐Liss, Inc.
Prevention of X‐ray‐induced late dermal necrosis in the pig by treatment with multi‐wavelength light
Authors: Rezvani Mohiaddin , Nissan Moshe , Hopewell John W. , van den Aardweg Gerard J. M. J. , Robbins Mike E. C. , Whitehouse Elizabeth M. 
Published: March 2007

AbstractLow‐level light from a multi‐wavelength array of light sources has been used to prevent late X‐ray‐induced dermal necrosis in the pig. Skin fields, measuring 4 × 4 cm on the flank, were irradiated with a single dose of 23.4 Gy of X‐rays. This X‐ray dose was associated with the development of a 100% incidence of dermal necrosis, 10–16 weeks after irradiation. These irradiated skin sites were subsequently exposed to light of 660, 820, 880, and 950 nm wavelengths from a gallium aluminium arsenide multiple wavelength multidiode cluster probe (Biotherapy Medical Laser, 3ML), three times a week, from 4 to 16 weeks or 6 to 16 weeks after X‐irradiation. The skin fields were exposed to the light pulsating at either 2.5 Hz or 5 kHz. With light pulsating at 5 kHz, energy densities of 0.22, 0.54, 1.08 2.16, 4.32, and 10.8 J/cm2 were used. Treatment with light pulsating at 2.5 Hz, 6–16 weeks after X‐irradiation, or treatment with light pulsating at 5 kHz, 4–16 weeks after X‐irradiation, did not have a significant effect on the incidence or the latency for the development of ischemia dermal necrosis irrespective of the exposure time to light at each treatment. With light pulsating at 5 kHz, no effect of light dose was observed. However, the overall incidence of dermal necrosis was significantly reduced (P = 0.001) to 52% in the X‐irradiated fields receiving treatment with 5 kHz light, 6–16 weeks after X‐irradiation. Treatment with light for only three days immediately after X‐irradiation with 5 kHz light had no beneficial effect. These findings suggest that light when applied appropriately may be useful in the prevention of late X‐ray‐induced damage to the dermis provided that it is given for the most appropriate time after X‐irradiation. © 1992 Wiley‐Liss, Inc.
Exogenous chromophores for the argon and Nd:YAG lasers: A potential application to laser‐tissue interactions
Authors: Brooks Stephen G. , Ashley Simon , Fisher John , Davies Gwilym A. , Griffiths John , Kester Ralph C. , Rees Michael R. 
Published: March 2007

AbstractChromophore dyes can be employed to modify laser‐tissue interaction. A number of dyes have been investigated for their effect on the absorption and transmission of argon and Nd:YAG laser energy by vascular tissue in vitro. Three histological dyes have been assessed as potential chromophores for the argon laser and four infrared dyes for the Nd:YAG. Segments of porcine coronary artery to which dye had been applied were lased (1,064 nm, 2.5 W, 83 W/cm2, 60 s and 488/514 nm, 400 mW, 10.5 W/cm2, 60s) and the tissue temperature measured remotely using an infrared thermometer. In addition, energy transmission was measured with a photodiode and tissue morphological changes assessed histologically.All three argon dyes significantly increased energy absorption (typically 60°C v. 20°C at 60 s, P < 0.001, 2‐way ANOVA). Three of the four infrared dyes behaved similarly (40–70°C v. 20°C, P < 0.001). All dyes significantly increased the initial rate of rise in tissue temperature during lasing. A reduction in energy transmission was observed for each of the Argon dyes but not for the Nd:YAG dyes. Histological evidence of thermal damage in control tissue first occurred for the argon and Nd:YAG lasers at 800 mW and 7.5 W without chromophore and at 400 mW and 2.5 W with the chromophore, respectively.A number of effective chromophores have therefore been identified at each wavelength. © 1992 Wiley‐Liss, Inc.
Use of the holmium:YAG laser in urology
Authors: Johnson Douglas E. , Cromeens Douglas M. , Price Roger E. 
Published: March 2007

AbstractThe tissue effects of a holmium:YAG (Ho:YAG) laser operating at a wavelength of 2.1μ with a maximum power of 15 watts (W) and 10 different energy‐pulse settings was systematically evaluated on kidney, bladder, prostate, ureteral, and vasal tissue in the dog. In addition, various urologic surgical procedures (partial nephrectomy, transurethral laser incision of the prostate, and laser‐assisted vasovasostomy) were performed in the dog, and a laparoscopic pelvic lymph node dissection was carried out in a pig. Although the Ho:YAG laser has a strong affinity for water, precise tissue ablation was achieved in both the contact and non‐contact mode when used endoscopically in a fluid medium to ablate prostatic and vesical tissue. Using the usual parameters for tissue destruction (blanching without charring), the depth of thermal injury in the bladder and ureter was kept superficial. In performing partial nephrectomies, a 2‐fold reduction in the zone of coagulative necrosis was demonstrated compared to the use of the continuous wave Neodymium:YAG laser (Nd:YAG). When used through the laparoscope, the Ho:YAG laser provided precise cutting and, combined with electrocautery, allowed the dissection to proceed quickly and smoothly. Hemostatic control was adequate in all surgical procedures. Although the results of these investigations are preliminary, our initial experience with the Ho:YAG laser has been favorable and warrants further investigations. © 1992 Wiley‐Liss, Inc.
Transurethral incision of the prostate using the holmium:YAG laser
Authors: Johnson Douglas E. , Cromeens Douglas M. , Price Roger E. 
Published: March 2007

AbstractTransurethral incisions of the prostate were made endoscopically in 5 dogs under a fluid medium using a holmium:YAG (Ho: YAG) laser operating at a wavelength of 2.1 μm and with delivery of 1.0 J/pulse in 15 Hz (15 W). Histopathologic examination of tissues collected immediately after surgery revealed irregular crevices outlined by a narrow zone of coagulative necrosis. Ulcerated fissures persisted at 5 and 7 days with the initial stages of epithelial regeneration partially re‐epithelializing the ulcerated surfaces. A modest inflammatory response characterized by edema, hemorrhage, and a mixed inflammatory cell infiltrate was also associated with the laser incision sites at 5 and 7 days. Three weeks postlasing, the ulcerated surfaces of the fissures were completely re‐epithelialized. At 5 weeks only a slight indentation persisted at the incision sites with minimal changes in the subjacent submucosa and prostatic glandular architecture. Although the results of these investigations are preliminary, we believe that the Ho:YAG laser warrants further clinical evaluation for treating patients with benign prostatic hyperplasia (BPH), urethral strictures, bladder neck contractures, and constrictions of the upper urinary tracts. © 1992 Wiley‐Liss, Inc.
Erb:YAG and Hol:YAG laser ablation of meniscus and intervertebral discs
Authors: Buchelt Martin , Kutschera Hans‐Paul , Katterschafka Thomas , Kiss Harald , Schneider Barbara , Ullrich Robert 
Published: March 2007

AbstractErb:YAG and Hol:YAG laser ablation rates of fibrocartilage and nucleus pulposus were measured in vitro simulating clinical conditions. After ablation macroscopic and microscopic appearance of the ablation site was investigated. Hol:YAG and Erb:YAG laser mean ablation rates increased almost linearly with rising energies, showing higher total ablation rates for the Hol:YAG laser due to its higher achievable energy density. At comparable energy densities the Erb:YAG laser appears to be more effective with respect to the corresponding ablation rates. Consequently, the ablational threshold proved to be lower for the Erb:YAG laser. Whereas during Hol:YAG laser ablation, some smoke formation and considerable tissue shrinking occurred, these effects could not be observed during Erb:YAG laser ablation. Consequently macroscopic and microscopic inspection showed some thermal damage after Hol:YAG and only minimal alterations after Erb:YAG laser ablation. Adjacent thermal damage was determined and proved to be lower for the Erb:YAG laser. In our opinion the characteristics of each laser system provide certain advantages for special clinical indications. © 1992 Wiley‐Liss, Inc.
Feasibility of skin deepithelialization using the contact Neodymium‐Yttrium‐Aluminum‐Garnet laser
Authors: Hallock Geoffrey G. , Rice David C. 
Published: March 2007

AbstractIn a manner similar to laserbrasion, the carbon dioxide (CO2) laser has a proven role for expediting skin deepithelialization, which is an essential component of many reconstructive procedures. However, the contact Neodymium‐Yttrium‐Aluminum‐Garnet (Nd:YAG) laser has many additional attributes such as tactile feedback and less plume that theoretically offer an advantage over the CO2 laser for this adjunctive maneuver. In rat experimental models and clinical applications, removal of the epidermis necessary for skin deepithelialization may indeed be achieved using a rounded probe for vaporization with the contact Nd:YAG laser. Unfortunately, the length of tune necessary for skin deepithelialization with the Nd:YAG laser exceeded even conventional methods, such that this role with the present technology, although possible, is inefficient and impractical. © 1992 Wiley‐Liss, Inc.
In vitro laser recanalization of chronically occluded prosthetic grafts
Authors: Kaelin Lawrence D. , Klingman Nina , Normann Sigurd J. , Seeger James M. 
Published: March 2007

AbstractPolytetrafluoroethylene (PTFE) and Dacron grafts were implanted in canine femoral and carotid arteries using PTFE and Prolene suture, respectively. Arteries containing occluded grafts were explanted and laser recanalization was attempted in vitro.Laser recanalization was successful in 78% of PTFE grafts compared to 30% of Dacron grafts. Recanalization was complete (residual stenosis < 5%) in opened PTFE grafts, whereas residual stenosis averaged 60% in recanalized Dacron grafts. PTFE graft/ PTFE suture anastomotic tensile strength was unchanged after recanalization, while Dacron graft/Prolene suture anastomotic tensile strength decreased significantly. In addition, anastomotic bursting pressure was significantly higher for lased PTFE grafts with PTFE sutures (300 mg Hg) compared to lased Dacron grafts with Prolene sutures (70 mm Hg).Chronically occluded PTFE grafts with PTFE suture can be safely and effectively opened by laser recanalization. In contrast, attempted laser recanalization of Dacron grafts sutured with Prolene suture is seldom successful, significantly weakens the graft artery anastomosis, and should be avoided.
Interstitial photoradiation injury of normal brain
Authors: Ji Ying , Walstad Diana , Brown J. Tony , Powers Stephen K. 
Published: March 2007

AbstractThe effect on normal brain of continuous interstitial laser irradiation at 630 nm through an implanted cylindrical‐shape, diffusion‐tipped optical fiber was studied in the rat. Brain water content in the laser irradiation area (LIA) and Evans blue (EB) dye content in selected areas of the brain were measured for different laser power outputs from 0 to 250 mW after 5 minutes of photo‐radiation. The degree and nature of tissue damage was examined histologically and correlated with the laser power level.There is significant brain damage, blood brain barrier (BBB) disruption, and brain edema in LIA for laser power outputs in excess of 100 mW from the diffusion tip (p < 0.001). Brain edema in the LIA is strongly correlated with BBB disruption indicated by the presence of EB. Histologically, the cortical surface was more susceptible than deeper white matter regions to interstitial laser irradiation. Possible indirect mechanisms of brain injury from interstitial laser irradiation are discussed. © 1992 Wiley‐Liss, Inc.
Therapeutic effect of Ga‐Al‐As diode laser irradiation on experimentally induced inflammation in rats
Authors: Honmura Akie , Yanase Masahiro , Obata Junichi , Haruki Eiichi 
Published: March 2007

AbstractWe produced experimental inflammation models in rats by carrageenin and studied the effect of Ga‐Al‐As diode laser irradiation (780 nm, continuous wave, 31.8 j/sec/cm2, spot size of 0.2 mm) on inflamed regions compared with those of indomethacin, a potent anti‐inflammatory agent. We found that a low‐power infrared laser has an anti‐inflammatory effect on carrageenin inflammation. A low‐power laser inhibits: (1) the increase of vascular permeability during the occurrence of an acute inflammation in the carrageenin‐air‐pouch model, (2) edema in the acute stage in the carrageenin‐paw‐edema model, and (3) the granuloma formation in the carrageenin‐granuloma model after receiving laser irradiation once daily. In all cases, irradiation for less than 10 min was sufficient to inhibit the inflammation by 20–30%. The inhibitory effect of laser irradiation was not comparable to that of indomethacin (4 mg/kg, i.o.) in the air‐pouch model and the paw‐edema model, whereas laser irradiation was more potent than that of daily administration of indomethacin (1 mg/kg, i.o.) in the granuloma model.In future studies of the mechanism of laser effect, it should be noted that irradiating a rat twice, before and after the provocation of inflammation, was essential in order to achieve an effective inhibition of paw‐edema. © 1992 Wiley‐Liss, Inc.
Effect of the ArF excimer laser on human enamel
Authors: Feuerstein Osnat , Palanker Daniel , Fuxbrunner Amihay , Lewis Aaron , Deutsch Dan 
Published: March 2007

AbstractHuman enamel surface was irradiated with ArF excimer laser and examined under light microscopy and scanning electron microscopy (SEM). Enamel surface was irradiated at three different areas with different energy fluences. It is demonstrated that the ArF excimer laser causes ablation of the calcified hard enamel tissue. Ablation curves were measured. There was no significant difference found in the etch depth between the three different areas of enamal surface. The morphology of the irradiated areas seen under the SEM was found to be dependent on energy flu‐ence. It changed with increase in energy fluence from being etched to forming a smooth, fused, glaze‐like surface and then at very high energy fluences producing a rough surface. The influence of the laser irradiation was confined to the irradiated area only, with no visible heat damage to the surroundings. These results suggest that excimer laser could be applied in a controlled and defined manner for tooth enamel treatments in dentistry. © 1992 Wiley‐Liss, Inc.
Preliminary evaluation of a new high power diode laser
Authors: Wyman Andrew , Duffy Sean , Sweetland Helen M. , Sharp Frank , Rogers Kenneth 
Published: March 2007

AbstractA high‐powered semiconductor diode laser (805 nm) has recently been developed for medical use. The laser‐tissue interactions of this wavelength have been compared with Nd:YAG (1064 nm). When used in the contact mode, the extent of tissue vaporization and zones of thermal necrosis produced by these two lasers were similar. The diode laser was also an effective and haemostatic laser scalpel. This compact laser unit has potential advantages over existing Nd:YAG lasers. © 1992 Wiley‐Liss, Inc.
Power density and exposure time of He‐Ne laser irradiation are more important than total energy dose in photo‐biomodulation of human fibroblasts in vitro
Authors: van Breugel Hans H. F. I. , Bär P. R. Dop 
Published: March 2007

AbstractThe absorption spectrum of human fibroblast monolayers showed several absorption peaks, among them one at a wavelength of 630 nm. Cultures of these fibroblasts were subjected to He‐Ne laser (632.8 nm) irradiation of various energy doses by varying power density and exposure time. On three consecutive days the cell monolayers were irradiated for periods between 0.5 and 10 min. Laser power varied from 0.55 to 5.98 mW. Both cell number and collagen type I production were determined for each irradiation condition within one experiment. Results show that laser power below 2.91 mW could enhance cell proliferation (as determined by cell counting), whereas higher laser power (5.98 mW) had no effect. Stimulatory effects were most pronounced at irradiation times between 0.5 and 2 min. Collagen type I production (as determined by an ELISA) was affected in the opposite direction to cell proliferation: when the cell proliferation was increased, collagen type I production was decreased. From these experiments it is clear that exposure time and power density determine the effects of laser irradiation. Both stimulation and inhibition of the observed cell properties can be obtained with the same laser on the same cells. © 1992 Wiley‐Liss, Inc.
EMLA for laser treatment of portwine stains in children
Authors: Tan O. T. , Stafford T. J. 
Published: March 2007

AbstractVascular‐specific lasers with pulse durations of between 300 and 500 microseconds are the treatment of choice for portwine stains (PWS), particularly in children. Although the discomfort felt following laser irradiation from a single pulse is transient, these sensations are intensified when multiple pulses are delivered over a confined area of skin. Because 75–80% of PWS are located in the head and neck regions, laser treatment of these sites tends to be more painful than those located in most other parts of the body. A prospective double blind randomized study, assessing pain during laser irradiation on PWS skin occluded with either EMLA, placebo, or no cream (control) was performed in 73 PWS subjects between 5 and 16 years of age. Analysis of the data showed that the pain scores for EMLA‐treated sites were the smallest, the control scores tended to be the highest, with the placebo scores in the middle. The differences between the treatments were significant (P < 0.0001). © 1992 Wiley‐Liss, Inc.
Initial results of endothelial cell seeding following argon laser carotid endarterectomy
Authors: Sawchuk Alan P. , Herring Malcolm B. , Dalsing Michael C. 
Published: March 2007

AbstractThis study evaluates the initial results of endothelial cell (EC) seeding following argon laser carotid endarterectomy. Venous endothelial cells were harvested from 12 dogs and cultured. A laser endarterectomy was performed on both carotids of each dog. One side was seeded with endothelial cells. Six dogs had both carotids harvested 1 hour after restoring blood flow. The others were harvested in 24 hours. The percentage of lumen covered with EC was evaluated by scanning electron microscopy. At 1 hour, the seeded arteries demonstrated 35 ± 3 percent EC coverage, whereas the unseeded arteries had no EC coverage (P = 0.0002). At 24 hours, the seeded arteries had 58 ± 15 percent EC coverage, whereas the unseeded arteries had no coverage (P = 0.01). Significant gross thrombus developed only in unseeded arteries (P = 0.047), two of which were occluded at 24 hours. EC seeding is beneficial following argon laser carotid endarterectomy resulting in improved patency and less surface thrombogenicty. © 1992 Wiley‐Liss, Inc.
Laser‐induced experimental vascular occlusion using liposome‐encapsulated ADP
Authors: Khoobehi Bahrain , Peyman Gholam A. , Bhatt Nitul , Moshfeghi Darius 
Published: March 2007

AbstractThe therapeutic occlusion of retinal vessels is often helpful in treating various pathological conditions. We compared the combined effects of argon laser photocoagulation and adenosine diphosphate (ADP) released from temperature‐sensitive liposomes with argon laser photocoagulation alone on occlusion of retinal vessels in pigmented rats.In Group A, 8 eyes were treated with liposome‐encapsulated ADP and laser photocoagulation. In Group B, 8 eyes were treated with laser photocoagulation alone. The laser parameters (power, spot size, exposure time) were maintained at the same levels for both groups. The laser was focused on the retinal vessels at the optic nerve head. The treated retinal vessels were observed at time zero, day 1, day 4, and weekly for a period of 3 months.At time zero, 6 of 8 eyes were totally occluded in Group A, with best results obtained at 80 mW. Only 1 of 8 eyes in Group B achieved total occlusion. After 3 months, 4 of 8 eyes in Group A remained totally occluded; no eyes in Group B were occluded. Complete and permanent occlusion of retinal vessels can be achieved by using ADP and laser photocoagulation of lower power density than traditional laser photocoagulation alone. © 1992 Wiley‐Liss, Inc.