bluuebunny/crossref_metadata_2025_split huggingface dataset:
Safe anesthesia for endoscopic laryngeal laser surgery
Authors: Anand Vijay K. , Herbert John , Robbett William F. , Zelman Warren H. 
Published: March 2007

AbstractAnesthesia safety for endoscopic laryngeal laser surgery has been a major limiting factor for laser applications in the larynx and the hypopharynx. Several anesthesia techniques have been proposed and each technique appears to have its own limitations. This paper will deal with the distinct advantages offered by the malleable copper tube which is used for delivery of the open Venturi system anesthesia for endoscopic laser surgery. A retrospective study of 100 patients who have undergone this modality of anesthesia at our institution will be presented. Our conclusion from this study shows clearly the superiority of the copper tube over the conventional aluminium‐foil‐wrapped endotracheal tube in safety and the exposure of the larynx during surgery.
Laser smoke effect on the bronchial system
Authors: Freitag L. , Chapman G. A. , Sielczak M. , Ahmed A. , Russin D. 
Published: March 2007

AbstractThe photoresection of endobronchial tumors produces smoke which is partly inhaled by the patient as well as the surgical staff. In an animal study we investigated whether a single exposure or repetitive exposures to smoke might have harmful side effects on the airways. Eleven sheep were exposed to smoke produced by laser‐vaporizing (6,500 J) sections of bronchial tissue (1 cm3) in a Plexiglas chamber. The smoke analysis revealed 0.92 mg/liter particles with a mean particle size of 0.54 μm. Carbon monoxide content was estimated as 0.04%. We measured the effects of one or three separate ten‐minute exposures on airway resistance, gas exchange, and mucociliary clearance rate in the trachea. We found that the smoke inhalation resulted in a decrease of arterial PO2 with relatively little change in airway mechanics. Tracheal mucus velocity, a marker of lung mucociliary clearance, was significantly depressed in a dose‐dependent manner with increasing smoke exposures. Results of bronchoalveolar lavages performed before and one day after the exposure showed that the smoke inhalation induced a severe inflammation with dramatic increases of inflammatory cells. The total number of cells per milliliter increases from 3.2 million to 25 million; percent neutrophils increased from 2.3 to 45.6% and percent macrophages decreased from 86 to 41%. These findings indicate that the side effects of smoke inhalation during intrabronchial laser surgery should not be neglected. The impairment of the defense mechanism of the lung combined with the inflammation as well as hypoxia might be fatal in compromised patients. Effective smoke removal devices should be developed to protect the patients as well as the surgeon.
CO2 laser in decubitus ulcers: A comparative study
Authors: Juri Hugo , Palma José A. 
Published: March 2007

AbstractThis is a comparative study of conventional surgery (knife/electric knife) and CO2 laser surgery and their effect on the outcome of stage III (including muscle) and stage IV (including bone) decubitus ulcers with an average area of 400 cm2.It is a prospective clinical study done with two groups of patients of similar age, economic and social background, as well with similar types of decubitus ulcers. Thirty patients were studied in each group.The study demonstrated a statistically significant difference in favor of the patients treated with CO2 laser with regard to operative blood loss, 0.5 cc/cm2 or 20% (P < .01). infection rate (χ2 test, P < .01), and difference (60%) in recovery time (P < .01). This translated into an average saving of 23 hospitalization days per patient.It also showed a difference, though not statistically significant, favoring the group treated with laser with respect to survival and full recovery. This probably is attributable to the lowered blood loss and infection rate as well as improved operative time and analgesia.
Molding of laser energy by shaped optic fiber tips
Authors: Ward Helen 
Published: March 2007

AbstractThe development of a new technique for laser recannalizing atheromatous vessels has inherent problems concerning heat damage to the vessel walls. A theoretical analysis of 2,100 light rays in large bulb end (output end) fibers compared to a standard flat end fiber showed (1) a much higher‐intensity focus; (2) a 125.4% increase in number of output rays (with respect to number of input rays) in the convergent output beam, due to multiple reflections/refractions (“stars” and “triangles”) and standing waves, in the large bulb end, compared to 48.6% in the flat end; (3) 83.69% energy in the converging beam of the large bulb end, compared to 48.6% in the flat end; (3) 83.69% energy in the converging beam of the large bulb end, compared to 46.1% energy in the flat end; and (4) a rapidly divergent beam after focus.Hence, theoretically a wide area of plaque could be burnt off more rapidly with less heat conduction into the vessel walls.Coupling efficiency was experimentally shown to be greatly increased by also having a bulb at the optic fiber input end.
Effects of simultaneous viewing and vaporization of plaques using the steerable, laser‐heated metal cap in the atherosclerotic monkey model
Authors: Theis Jerold H. , Lee Garrett , Chan Ming C. , Ikeda Richard M. , Lee Marshall H. , Rink John L. , Steffey Eugene P. , Thomas William P. , Mason Dean T. 
Published: March 2007

AbstractA steerable, fiberoptic catheter coupled to a laser light guide tipped with a metal cap was used. Four monkeys fed an atherogenic diet for 7–8 years were angiographed and were found to have extensive mural plaque in the iliac arteries. Plaque sites in these monkeys were vaporized using the laser‐heated metal cap. Energies of 1.5–9 Joules were employed. Application of the energy was tangential or perpendicular to the plaque. Lased sites were examined histologically at 24 hr or at 3 months after treatment. No effect was seen at 1.5 Joules. Three to six Joules tangentially produced a superficial lesion that extended into the tunica intima. Six Joules perpendicularly produced a burn into the tunica adventitia, with damage to the vasavasorum. Nine Joules tangentially produced a burn into the tunica media. Three months after treatment, this lased site showed no stenosis or aneurysm formation.
Evaluation of sapphire tip Nd:YAG laser fibers in partial nephrectomy
Authors: Landau Stewart T. , Wood Thomas W. , Smith Joseph A. 
Published: March 2007

AbstractSapphire tips for Nd:YAG lasers fibers have been introduced recently. The increased energy density improves the cutting effect while, reportedly, preserving the hemostatic properties of Nd:YAG laser energy. The capacity of sapphire tip laser fibers to facilitate partial nephrectomy was tested in mongrel dogs. No advantage for this technique was demonstrated compared to standard methods of partial nephrectomy.
Differential effects of short‐ and long‐pulsewidth laser exposures on retinal ganglion cell response
Authors: Glickman Randolph D. 
Published: March 2007

AbstractTime‐dependent effects of laser exposures on rhesus monkey retinal ganglion cells were studied with a Q‐switched, doubled Nd:glass laser, which produced 20 nsec pulses of 530‐nm light, and a continuous‐wave (CW) argon laser (514.5 nm), which produced exposures of 0.1‐msec to 0.1‐sec duration. Ganglion cell activity was recorded in situ by means of an intraocular electrode. Ganglion cells exposed to a single 20‐nsec exposure, at a sublesion intensity, produced a 60–90 sec discharge of action potentials and exhibited a 2 log or greater elevation of light threshold, depending on beam size and intensity. At equivalent energy levels, the longer exposures produced the same or slightly weaker effects. This result is not as straightforward as it seems. Submillisecond flashes bleach no more than 50% of the visual pigment because of photoregeneration. The Dowling‐Rushton relation predicts that a 50% bleach should produce only a 1.5 log loss of cone sensitivity. Exposures longer than 1 msec should not photoregenerate pigment (ie, more pigment will be bleached for a given exposure intensity). In view of the probable differences in pigment bleaching, it appears that the Q‐switched laser light adapts the cells out of proportion to the visual pigment actually bleached—a single‐cell analogue of Rushton's “theta” effect.
Effect of diodes‐laser silver arsenide‐aluminium (Ga‐Al‐As) 904 nm on healing of experimental wounds
Authors: Longo Leonardo , Evangelista Stefano , Tinacci Galliano , Sesti Anton Giulio 
Published: March 2007

AbstractDiodes‐laser silver arsenide‐aluminum (Ga‐Al‐As) 904 nm, which was used because of its properties of good tissue penetration and manageability, applied 5 min daily for 5 days at 3,000 Hz of frequency (energy density = 3 J), promoted healing of experimental wounds in rats from both a microscopic and histologic point of view. The same laser applied in these experimental conditions (number of rats was eight for each group) at the same energy density (3 J) for 10 min daily during 5 days at 1,500 Hz of frequency did not affect the experimental wounds.
Endogenous porphyrin fluorescence in tumors
Authors: Harris David M. , Werkhaven Jay 
Published: March 2007

AbstractThe fluorescence of endogenous porphyrins in tumors has been attributed to the presence of several different species of bacteria inhabiting ulcerated and necrotic tissues. We have examined this “autofluorescence” in carcinogen‐induced tumors in the hamster oral mucosa and in patients with cancer of the oral cavity. In several instances, bright autofluorescence of normal tissues has been observed. This represents a potential false‐positive identification of cancer when systemic hematoporphyrin derivative fluorescence is used as a diagnostic technique.
Laser microsurgery in oncology: Indications, techniques, and results of 5‐year experience
Authors: Bandieramonte G. , Chiesa F. , Lupi M. , Marchesini R. 
Published: March 2007

AbstractMultidisciplinary collaboration has enabled us to the CO2 laser in many different surgical fields. The 5‐year experience at the National Tumor Institute of Milan is reviewed for the evaluation of short‐ and medium‐term results of 321 laser surgical operations of the lower genital tract, 475 cases of lesions of the larynx and oral cavity, and 246 cases of skin lesions. A unified approach was used as regards safety measures, preoperative evaluation, and rules of application of laser instruments. The reliability of the surgical procedures, the proper selection of the cases, and the low rate of postoperative complications allowed outpatient treatment in 76% of the cases, thus reducing the hospitalization costs. The use of the microscope for laser resections under magnification was recognized to be preferable in routine surgical oncology practice. Short‐ and medium‐term clinical results with laser microsurgery were comparable to those with conventional surgery, especially when precise and conservative removal of periorificial lesions was required.
Laser therapy of tumor stenoses in the upper gastrointestinal tract: An international inquiry
Authors: Ell C. , Demling L. 
Published: March 2007

AbstractThe results of an international inquiry on palliative laser therapy of malignant inoperable stenoses in the upper gastrointestinal tract are reported. The results of the treatment of a total of 1,359 patients were collected. The data from laser users with experience in more than 50 treated patients (n = 1,184) were analyzed; 68.9% of the tumor stenoses were located in the esophagus, and 55.7% were not passable with the endoscope. The initial treatment was successful in 83.0% and the complication rate was 4.1% (49 of 1,184 patients). The mortality rate was 1.0% (12 of 1,184 patients).
Argon laser treatment of telangiectasia of the face and neck: 5 Years' experience
Authors: Achauer Bruce M. , Kam Victoria M. Vander 
Published: March 2007

AbstractThis study documents the treatment and long‐term follow‐up of telangiectasias of the face and neck with the argon laser. This study concurs with other examiners that treatment is effective with minimal complications and satisfactory long‐term results.
Laser balloon angioplasty: Effect of constant temperature versus constant power on tissue weld strength
Authors: Anand Raj K. , Sinclair I. Nigel , Jenkins Ronald D. , Hiehle John F. , James Leslie , Spears J. Richard 
Published: March 2007

AbstractThermal fusion of intimal plaque with the arterial wall during coronary balloon angioplasty may significantly reduce the incidence of abrupt closure and may reduce the occurrence of delayed restenosis by improvement of luminal size and shape. Although Nd:YAG laser energy has been shown to be effective in the thermal fusion of plaque‐arterial wall separations in vitro, the most efficient manner of energy delivery for rapid achievement of therapeutically useful equilibrium tissue temperature during laser exposure has not been defined. A comparison of weld strength achieved was therefore made between two formats of laser delivery: constant power vs. decremental power with an initial high dose followed by the minimal serial decrements necessary to maintain tissue temperature constant for 15 seconds. One hundred sixty‐six tissue discs of human postmortem aorta of 11 mm diameter were studied. Intimal plaque was separated from the media, the two layers were juxtaposed, a force of 4 pounds was applied, and a fiberoptic‐delivered laser beam was directed perpendicular to the tissue over a 3‐mm‐diameter nominal spot size. Weld strength was measured as the shear force required to separate completely the two tissue layers. The mean weld strength (75 g) achieved by use of the decremental power format was significantly higher (P < .01) than the mean strength (32 g and 56 g) achieved by using constant power for 20 and 30 seconds, respectively. The total laser energy used for the decremental power format was 235 joules, which was significantly less than the 320 and 480 joules used when constant power exposure for 20 and 30 seconds, respectively, was employed, despite the fact that the peak tissue temperature was similar for all three groups. It is concluded, therefore, that the use of decremental power to achieve quickly and, thereafter, to maintain a constant temperature provides better tissue weld strength at a lesser energy cost and hence is superior to the use of constant power.
Gas volume quantitation during argon ion laser ablation of atheromatous aorta in blood and 0.9% saline media with an optically shielded catheter
Authors: Davis G. Stefan , Bott‐Silverman Corinne , Goormastic Marlene , Gerrity Ross G. , Kittrell Carter , Feld Michael , Kramer John R. 
Published: March 2007

AbstractUsing an optically shielded fiber optic laser catheter, the amount of gas produced when firing an argon ion laser into 0.9% saline solution or blood alone and into atheromatous aorta in either a blood or 0.9% saline medium was quantitated. Energies from 0.25 to 4 joules (J) were used at powers of 2, 5, and 8 W. We found that total volume of gas produced is small not only at equilibrium (0.3 ± 0.1 μl/J when firing in blood alone and also when ablating aorta in blood or saline media) but also at peak (2.5 ± 0.2 μl/J firing in blood alone and 1.0 ± 0.1 μl/J or 0.9 ± 0.1 μl/J when ablating aorta in saline or blood, respectively). Because these volumes are small, a clinically significant event from a gas embolus is unlikely during intravascular laser ablation of atheromatous plaque in the energy and power range studied. No gas was quantitated when firing the argon ion laser into 0.9% saline solution alone. The peak gas volume when firing in blood alone was significantly greater than that produced in the other chamber environments. This is thought to be due to increased absorption of argon laser light by hemoglobin. The gas volumes produced by lasing aorta in 0.9% saline or blood were not statistically different.
Nd‐YAG laser energy distribution in an artificial obstruction: Influence of lasing parameters in a model of laser angioplasty
Authors: Rienks Rienk , Verdaasdonk Ruud M. , Borst Cornelius , Smits Peter C. , Jambroes George , van Gemert Martin J. C. , de Medina Etienne O. Robles , Hitchcock J. François 
Published: March 2007

AbstractA Nd‐YAG laser (1064 nm) coupled to a silica fiber (0.6 mm core diameter) was used to create defects in a model of arterial vascular obstruction. We employed transparent agar doped with black ink as atheromatous material and studied the size and shape of defects created by various lasing parameter settings. By adding calcium sulphate to the agar its scattering properties were enhanced. The created defects correspond to a temperature boundary. The optical properties of the agar greatly influenced the size and shape of the created defects. In the agar with enhanced scattering properties, the created defects showed an infavourable penetration width‐depth ratio. Maximum width of penetration always exceeded the fiber diameter. This may contribute to an increased risk of vessel wall perforation in small vessels and, if the fiber is positioned close to the vessel wall, even when a coaxial position is maintained.With increasing cumulative energy, both maximum depth and width of penetration leveled off in both agars. The results suggest that agar can be used to obtain empirically the lasing parameters that will minimize the risk of vessel wall perforation by an axially positioned fiber. The agar model needs further study to determine its limitations, but agar seems to be a useful substitute for atheroma in the study of laser catheter angioplasty.
Does low‐energy helium‐neon laser irradiation alter “in vitro” replication of human fibroblasts?
Authors: Hallman H. O. , Basford J. R. , O'Brien John F. , Cummins Laura A. 
Published: March 2007

AbstractCultured human fibroblasts were treated in a controlled, randomized manner to assess the effect of low‐energy (0.9 mW) helium‐neon (HeNe) laser irradiation on cellular proliferation. Two trials were performed: one with fibroblasts in the third to fourth passage and the other with fibroblasts in the 13th to 14th passage. In each trial, separate plasticpetri dishes were inoculated with the cells, maintained in a 5% CO2‐95% air atmosphere, and nourished with HB 102 media. Treatment began 48 h after inoculation with daily 60‐s irradiations of the “treated” cultures over a 5‐d period. Control cultures underwent the same handling but were not irradiated. A significant stimulative, or inhibitive, effect on replication was not found in either trial.
Prospective study of cutaneous phototoxicity after systemic hematoporphyrin derivative
Authors: Wooten Robert S. , Smith Kevin C. , Ahlquist David A. , Muller Sigfrid A. , Balm Rita K. 
Published: March 2007

AbstractHematoporphyrin derivative (HpD) is a photoactive, oncophilic substance that produces cutaneous photosensitivity as its only significant side effect. Twenty‐three patients who received systemic HpD and the usual light‐avoidance precautions were studied prospectively to determine the incidence and severity of cutaneous phototoxicity (CP). Seventeen of the 23 patients (74%) reported CP, including three patients (18%) who experienced blister formation. Symptoms of CP occurred for a mean duration of 6 weeks (range 5–23 weeks). Lack of compliance with restrictive photoprotective measures was felt to be a major contributing factor. Other HpD‐related complications included skin hyperpigmentation, ocular discomfort, pruritus, pain at injection site, and urticaria. CP and the restrictive measures to avoid it represent major disadvantages of the clinical use of HpD.
Laser angioplasty: An atherosclerotic swine model
Authors: White Christopher J. , Ramee Stephen R. , Card Hal G. , Abrahams Lisa A. , Svinarich J. Thomas , Wade Charles E. , Rodkey William G. , Virmani Renu 
Published: March 2007

AbstractRapid production of occlusive, atherosclerotic iliac artery lesions was achieved in 25 of 27 (93%) Yucatan miniature swine, using a combination of high cholesterol diet and mechanical endothelial denudation. Animals were fed a diet with 2% of their calories as raw cholesterol 2 weeks prior to balloon denudation of iliac arteries, which resulted in atherosclerotic lesions within 8 weeks. Early after denudation we have demonstrated total occlusion of arteries by fibrin thrombi, which in time organize and ultimately result in fibrotic occlusive disease. The arterial walls and intima show varying degrees of foam cell infiltration with destruction of the internal elastic lamina and calcification. Totally occluded lesions show fibrointimal proliferation, fibrosis, and multiluminal channels, which are probably secondary to organized thrombus. Our model of occlusive iliac artery disease involving vessels of 1 to 3 mm in diameter allows the development of catheter systems suitable for use in human peripheral and coronary arteries. This model is useful for the study of angioplasty, whether mechanical, balloon, or laser‐mediated.
The pulsed dye laser versus the Q‐switched Nd:YAG laser in laser‐induced shock‐wave lithotripsy
Authors: Thomas Stephen , Pensel Jürgen , Engelhardt Ralf , Meyer Wilhelm , Hofstetter Alfons G. 
Published: March 2007

AbstractTo date, there are two fairly well‐established alternatives for laser‐induced shock‐wave lithotripsy in clinical practice. The Q‐switched Nd:YAG laser is distinguished by the high‐stone selectivity of its coupler systems. The necessity of a coupler system and its fairly small conversion rate of light energy into mechanical energy present serious drawbacks. Furthermore, the minimal outer diameter of the transmission system is 1.8 mm.The pulsed‐dye laser can be used with a highly flexible and uncomplicated 200‐μm fiber. However, the laser system itself is more complicated than the Q‐switched Nd:YAG laser and requires a great deal of maintenance. Biological evaluation of damage caused by direct irradiation shows that both laser systems produce minor damage of different degrees.YAG laser lithotripsy with the optomechanical coupler was assessed in 31 patients with ureteral calculi. The instability and limited effectiveness of the fiber application system necessitated auxiliary lithotripsy methods in 14 cases. Dye‐laser lithotripsy is currently being tested in clinical application.Further development, such as systems for blind application or electronic feedback mechanisms to limit adverse tissue effects, have yet to be optimized.Nevertheless, laser‐induced shock‐wave lithotripsy has the potential to become a standard procedure in the endourologic management of stone disease.
Infrared laser bone ablation
Authors: Nuss Roger C. , Fabian Richard L. , Sarkar Rajabrata , Puliafito Carmen A. 
Published: March 2007

AbstractThe bone ablation characteristics of five infrared lasers, including three pulsed lasers (Nd:YAG, λ = 1,064 μm; Hol:YSGG, λ = 2.10 μm; and Erb:YAG, λ = 2.94 μm) and two continuous‐wave lasers (Nd:YAG, λ = 1.064 μm; and CO2, λ = 10.6 μm), were studied. All laser ablations were performed in vitro, using moist, freshly dissected calvarium of guinea pig skulls. Quantitative etch rates of the three pulsed lasers were calculated. Light microscopy of histologic sections of ablated bone revealed a zone of tissue damage of 10 to 15 μm adjacent to the lesion edge in the case of the pulsed Nd:YAG and the Erb:YAG lasers, from 20 to 90 μm zone of tissue damage for bone ablated by the Hol:YSGG laser, and 60 to 135 μm zone of tissue damage in the case of the two continuous‐wave lasers. Possible mechanisms of bone ablation and tissue damage are discussed.