bluuebunny/crossref_metadata_2025_split huggingface dataset:
Massive air embolism complicating Nd‐YAG laser endobronchial photoresection
Authors: Golish Joseph A. , Pena Cesar M. , Mehta Atul C. 
Published: March 2007

AbstractA 63 year old male underwent 6,900 rads of external radiation for a squamous cell carcinoma of the left main bronchus. Recurrence of the tumor 8 months later was treated with 6,618 joules and patency of the left main bronchus was restored. Four months later, he developed complete atelectasis of the left lung requiring repeat laser. During the procedure he became hypotensive, bradycardic, and hypoxic due to a tension pneumothorax. Although treated promptly with thoracostomy tube drainage, the patient never awakened. CT scan of the brain demonstrated anoxic encephalopathy with air present in the right frontal lobe. Brain death was confirmed by an EEG and cerebral angiogram.Air embolism has been reported in conjuction with diagnostic procedures including therapeutic pneumothorax for tuberculosis, transthoracic needle biopsy of the lung, and positive pressure ventilation with or without pneumothorax. The only reported case of air embolism associated with laser was a small middle cerebral artery cerebrovascular accident which was self limited. Its mechanism is unclear, but it is suspected to be due to a communication between a pulmonary vein and the atmosphere. A greater volume of air will enter the damaged vessel in the setting of positive pressure ventilation and/or a tension pneumothorax. When neurologic manifestations are present, hyperbaric oxygen therapy is the treatment of choice. Prompt institution in hemodynamically stable patients can minimize neurologic sequelae. © 1992 Wiley‐Liss, Inc.
Photoacoustic injury and bone healing following 193nm excimer laser ablation
Authors: Lustmann Joshua , Ulmansky Mario , Fuxbrunner Amihay , Lewis Aaron 
Published: March 2007

AbstractThe argon‐fluoride excimer laser was investigated as a cutting‐ablating tool for bone surgery. A total of 52 rats were divided into two experimental groups and two control groups. In one experimental group cortical bone defects were made; in another experimental group defects penetrating into the medullary space were performed. In the two control groups similar defects were achieved using water‐cooled carbide burs. The rats were sacrificed on each of the 3, 7, 10, 20, 30, and 40 postoperative day. The cortical bone, the medullary space, and the extrabony tissue were examined by means of light microscopy. In both experimental groups, bone damage, represented by osteocyte destruction, extended to 1,050–1,450 μm ahead from the irradiated site, and bone healing was very much impaired. In the control groups no histological changes could be identified and bone healing appeared to be within normal limits. We believe this extensive bone damage, following 193 nm irradiation, to be a result of photoacoustic waves propagating in the bone following each pulse. In view of our results we feel that excimer lasers presently in use are not suitable for bone surgery. This problem of photoacoustic damage can be overcome in one of two ways: by designing a CW excimer laser or by reducing the pulse width to the picosecond regime. © 1992 Wiley‐Liss, Inc.
Effects of coaxial CO2/Nd:YAG irradiation on periodontal wound healing
Authors: Arcoria Charles J. , Steele Robert E. , Vitasek Bunny A. , Wagner Martin J. 
Published: March 2007

AbstractThis study evaluated a coaxial CO2/Nd:YAG laser used during periodontal surgery in mongrel dogs for the purpose of ablating the osseous portions of root surfaces to increase reattachment of soft tissue. Periodontal defects were produced with ligatures of orthodontic wire and elastics. The left mandibular osseous root surfaces were irradiated with a defocused, CW laser beam [power density (PD) = 42.46 W/cm2, energy density (ED) = 424.63 J/cm2]. The left maxillary osseous root surfaces were treated with a beam at twice the energy density [PD = 84.93 W/cm2, ED = 849.3 J/cm2]. The mandibular right quadrant received conventional surgery and the maxillary right quadrant served as the untreated control. Fourteen days after treatment, facial/lingual attached gingivae were scored for soft tissue adherence to bone. Laser irradiation at low ED did not improve soft tissue attachment when compared to conventional treatment. Higher ED irradiation produced significantly less attachment and increased tissue necrosis. © 1992 Wiley‐Liss, Inc.
Microprocessor‐Controlled Nd:YAG laser for hyperthermia induction in the RIF‐1 tumor
Authors: Waldow Stephen M. , Russell Gail E. , Wallner Paul E. 
Published: March 2007

AbstractNear‐infrared radiation from a Nd:YAG laser at 1,064 nm was used interstitially or superficially to induce hyperthermia in RIF‐1 tumors in C3H male mice. A single 600‐μm quartz fiber with a 0.5‐cm cylindrical diffusor or a weakly diverging microlens at its distal end was used to deliver laser energy to tumors in the hind leg (mean volume = 100 mm3). Two thermocouples were inserted into each tumor. One thermocouple controlled a microprocessor‐driven hyperthermia program (maximum output of 3.5 Watts) to maintain the desired temperature. Tumors were exposed to various temperature‐time combinations (42–45°C/30 min). Our initial results indicated that excellent temperature control to within 0.2°C of the desired temperature at the feedback thermocouple was achievable during both superficial and interstitial heat treatments. Temperatures at the second thermocouple, however, were found to be lower by as much as 2.3°C (using the cylindrical diffusor) or higher by up to 4.6°C (using the microlens) when compared to the feedback thermocouple temperature. Several correlations were seen between total dose, tumor growth delay, percent skin necrosis, and temperature at the second thermocouple after several superficial and interstitial treatments. Statistically significant improvements in tumor growth delay (at 42 and 45°C) and increased percent skin necrosis at all temperatures were observed after superficial versus interstitial treatment. © 1992 Wiley‐Liss, Inc.
Comparison of holmium and flashlamp pumped dye lasers for use in lithotripsy of biliary calculi
Authors: Spindel Mitchell L. , Moslem Ali , Bhatia Kuldip S. , Jassemnejad Bahaeddin , Bartels Kenneth E. , Powell Richard C. , O'Hare Ciaran M. , Tytle Tim 
Published: March 2007

AbstractThe characteristics of laser lithotripsy of biliary calculi are compared for a flashlamp pumped dye laser (λ = 640 nm) and a Cr: Tm:Ho‐YAG laser (λ = 2.1 μm). Data on fragmentation efficiency with respect to laser power and pulse repetition rate are presented for different types of stones. It is shown that both lasers can produce effective stone fragmentation. The laser power required for efficient fragmentation characteristics is significantly less for the visible wavelength laser. However, the problems associated with damage to the fiber tips of the delivery system during operation were found to be less with the near infrared wavelength. The laser power for efficient fragmentation with the dye laser varies significantly for different types of stones while the power for efficient fragmentation with the hohnium laser is the same for all stones. © 1992 Wiley‐Liss, Inc.
Treatment of distal ureteral tumors using endoscopic argon photoirradiation
Authors: Johnson Douglas E. 
Published: March 2007

AbstractThis is the first report on the use of endoscopic argon photoirradiation to treat patients with low‐grade ureteral tumors involving the distal ureter. Using a rigid ureteropyeloscope, a 300 μ, or 600 μ quartz fiber, and 5 watts (W) of power in a continuous‐wave mode, the lesions were ablated without complication. Patients remain free of ureteral recurrence after 5, 7, and 22 months. We conclude that the shallow (1 mm) depth of penetration and the ability to use the fiber in either a contact or noncontact mode provide the surgeon a large margin of safety and low risk of ureteral perforation. © 1992 Wiley‐Liss, Inc.
Changes in type I collagen following laser welding
Authors: Bass Lawrence S. , Moazami Nader , Pocsidio Joanne , Oz Mehmet C. , Logerfo Paul , Treat Michael R. 
Published: March 2007

AbstractSelection of ideal laser parameters for tissue welding is inhibited by poor understanding of the mechanism. We investigated structural changes in collagen molecules extracted from rat tail tendon (> 90% type I collagen) after tissue welding using an 808 nm diode laser and indocyanine green dye applied to the weld site. Mobility patterns on SDS‐PAGE were identical in the lasered and untreated tendon extracts with urea or acetic acid. Pepsin incubation after acetic acid extraction revealed a reduction of collagen alpha and beta bands in lasered compared with untreated specimens. Circular dichroism studies of rat tail tendon showed absence of helical structure in collagen from lasered tendon. No evidence for covalent bonding was present in laser‐treated tissues. Collagen molecules are denatured by the laser wavelength and parameters used in this study. No significant amount of helical structure is regenerated on cooling. We conclude that non‐covalent interactions between denatured collagen molecules may be responsible for the creation of tissue welding. © 1992 Wiley‐Liss, Inc.
XeCl laser ablation of atherosclerotic aorta: Optical properties and energy pathways
Authors: Oraevsky Alexander A. , Jacques Steven L. , Pettit George H. , Saidi Iyad S. , Tittel Frank K. , Henry Philip D. 
Published: March 2007

AbstractThe energetics of 308‐nm excimer laser irradiation of human aorta were studied. The heat generation that occurred during laser irradiation of atherosclerotic aorta equaled the absorbed laser energy minus the fraction of energy for escaping fluorescence (0.8–1.6%) and photochemical decomposition (2%). The absorbed laser energy is equal to the total delivered light energy minus the energy lost as specular reflectance (2.4%, air/tissue) and diffuse reflectance (11.5–15.5%). Overall, about 79–83.5% of the delivered light energy was converted to heat. We conclude that the mechanism of XeCl laser ablation of soft tissue involves thermal overheating of the irradiated volume with subsequent explosive vaporization. The optical properties of normal wall of human aorta and fibrous plaque, both native and denatured were determined. The light scattering was significant and sufficient to cause a subsurface fluence (J/cm2) in native aorta that equaled 1.8 times the broad‐beam radiant exposure, Φo (2.7Φo for denatured aorta). An optical fiber must have a diameter of at least 800 μm to achieve a maximum light penetration (≈200 mu;m for μo/e) in the aorta along the central axis of the beam. © 1992 Wiley‐Liss, Inc.
Effects of rapid pulsed CO2 laser beam on cortical bone in vivo
Authors: Rayan Ghazi M. , Stanfield Denver T. , Cahill Sandy , Kosanke Stanley D. , Kopta Joseph A. 
Published: March 2007

AbstractTwenty rabbit femurs were used to study the effect of CO2 laser on cortical bone. Sixteen femurs were treated with 20 watts, 3 mm defocused beam, 2 KHZ spike pulse mode CO2 laser for 10 seconds through a circular window in the metaphysis. In four control femurs, the inner cortex was exposed without laser treatment. The animals were killed at 4 and 6 weeks and the specimens studied histologically. All laser‐treated specimens showed thermal changes. Three histological zones were observed. A superficial zone of inner cortex close to the beam consisted mainly of carbonization or carbon ash during resorption. An intermediate zone consisted of bone necrosis and healing with associated areas of new bone formation. The deep zone of outer cortex had normal bone with no cellular damage. No such changes were observed in the control specimens. The CO2 laser can be used to generate a controlled zone of tissue ablation, which may make it a potentially useful tool for tumor margin cauterization. © 1992 Wiley‐Liss, Inc.
Clinical application of the Nd:YAG laser bipolar dissector in intra‐abdominal surgery
Authors: Nishiwaki Yoshiro , Daikuzono Norio , Joffe Stephen N. 
Published: March 2007

AbstractA laser bipolar dissector (LBD) using a 1064 nm Nd:YAG laser energy source that provides hemostatic dissection using lowpowered laser energy (15–25 W) has been developed. Clinical applications have included a partial hepatectomy (n = 5), a cholecystectomy (n = 4), an appendectomy, lymphnode dissection, and division of adhesions. The LBD was effective in resection of noncirrhotic liver and reduced the number of ligations required. There were no direct complications related to using the LBD. Operative time and blood loss were difficult to compare to conventional methods. The LBD may have applications for partial hepatectomies and other intra‐abdominal operations. © 1992 Wiley‐Liss, Inc.
Interstitial laser photocoagulation: Nd:YAG 1064 nm optical fiber source compared to point heat source
Authors: Wyman D. R. , Whelan W. M. , Wilson B. C. 
Published: March 2007

AbstractInterstitial laser photocoagulation (ILP) was performed in vitro in lean bovine and chicken muscle by delivering 1.6 W of continuous‐wave Nd:YAG laser energy (1064 nm) from a 400‐μm core optical fiber for 300s. The resulting thermal coagulation lesion was consistently larger when the delivered energy was deposited into a small steel sphere than when it was delivered freely into the tissue. Mathematical modelling confirms this result. This preliminary study suggests that a point heat source produces a larger volume of thermal coagulation than a point optical source (1064 nm) delivering the same power. © 1992 Wiley‐Liss, Inc.
Laser‐induced hyperthermia: Comparison of two different methods
Authors: Castrén‐Persons Maaret , Lipasti Jarmo , Puolakkainen Pauli , Schröder Tom 
Published: March 2007

AbstractThe effectiveness of two different techniques of laser‐induced hyperthermia was analyzed in healthy piglet livers. Hyperthermia was produced using a continuous‐wave Nd:YAG laser with both a contact sapphire probe and a bare quartz fibre. In both methods the tip was inserted into the liver, and the temperature 1 cm from the tip was raised and held between 42°C and 44°C for 600 seconds. Specimens were taken 0, 7 and 14 days after the treatment. The tissue effects of 36 treatment sites were analysed using standard van Gieson's method. In addition, a histochemical method for demonstrating lactate dehydrogenase activity was employed to show damage not observable by routine methods. No statistically significant difference in the extent of the treatment sites at d 0 and after 7 days was seen when comparing the two laser methods. After 2 weeks, the diameter of the lesion with the bare fibre was significantly larger (3,7 mm with both analysing methods) than by using the contact probe (2,6 with LDH demonstration; P < 0.01 and 2,1 mm with van Gieson's staining; P < 0.001). It can be concluded that the simple fibre tip seems more effective in causing tissue necrosis than the sapphire tip. © 1992 Wiley‐Liss, Inc.
Photoinhibition of smooth muscle cell migration: Potential therapy for restenosis
Authors: Deckelbaum Lawrence I. , Scott John J. , Stetz Mark L. , O'Brien Kenneth M. , Sumpio Bauer E. , Madri Joseph A. , Bell Leonard 
Published: March 2007

AbstractEvidence from animal, autopsy, and atherectomy studies demonstrates that migration and proliferation of smooth muscle cells of medial origin result in neointima formation and decreased luminal cross‐sectional area. The purpose of this study was to evaluate whether low energy light irradiation can inhibit smooth muscle cell migration and therefore potentially reduce the degree of neointima formation and the incidence of restenosis. The migration kinetics of bovine aortic smooth muscle cell monolayers were examined using a fence assay. The effect on smooth muscle cell migration of irradiation with monochromatic light at wavelengths ranging from 400 to 700 nm was compared to the migration of cells irradiated with broadband white light or maintained in the dark. Wavelength specific photoinhibition of smooth muscle cell migration was observed; 594–600 nm light reproducibly inhibited migration by 12–29% (P < 0.05). Migration rate was significantly reduced following daily radiant exposures of 1.0 J/cm2 as well as following a single radiant exposure of 0.09 or 0.9 J/cm2. The decrease in migration was not associated with any change in cell proliferation or [3H] thymidine incorporation. We conclude that 594–600 nm light inhibits smooth muscle cell migration in vitro and may potentially be used in vivo to decrease fibrointimal thickening following arterial injury. This application of photoinhibition may be useful in retarding restenosis following angioplasty. © 1993 Wiley‐Liss, Inc.
Optical properties of rat liver and tumor at 633 nm and 1064 nm: Photofrin enhances scattering
Authors: van Hillegersberg Richard , Pickering John W. , Aalders Maurice , Beek Johan F. 
Published: March 2007

AbstractPredicting the effects of photodynamic therapy (PDT) and Nd: YAG laser coagulation requires knowledge of the light distribution in tumor and surrounding tissue. Therefore, absorption and scattering coefficients and the average cosine of the scattering angle (the anisotropy factor) were measured in rat liver and tumor at 632.8 and 1064 nm. A syngenic colon adenocarcinoma CC531 was implanted subcutaneously in two groups of 7 Wag/Rij rats. In one group Photofrin was administered 5 mg/kg intravenously 48 h before determination of optical properties. Two months after inoculation, samples were taken from tumor and liver and optical properties determined using indirect methods with two integrating spheres. The absorption coefficient was larger in liver than in tumor at 632.8 nm (P < 0.0005), whereas the scattering coefficient was larger in tumor than in liver at 1,064 nm (P < 0.05). Addition of Photofrin increased the scattering coefficient in liver and in tumor at both wavelengths (P < 0.025) and decreased the anisotropy in tumor (P < 0.025), suggesting that for modelling the dosimetry of PDT the optical properties of photosensitized tissue should be used. © 1993 Wiley‐Liss, Inc.
Effects of ArF: Excimer laser irradiation on human enamel and dentin
Authors: Arima Mari , Matsumoto Koukichi 
Published: March 2007

AbstractRound enamel and dentin surfaces of sound and carious extracted human teeth were irradiated by an ArF:excimer laser for up to 180 sec. Thermographic measurements indicated that the temperature rise due to heat accumulation caused by laser irradiation on these enamel and dentin surfaces was up to 19°C (10 HZ with 540 J/cm2), and the temperature returned to the preirradiation value within 10 sec after the irradiation was stopped. Under light microscopy, no carbonization was evident on these surfaces, and a simple recess was formed by abrasion or vaporization in the irradiated regions. In the secondary SEM, uniformly distributed fine pores and prism structures appeared slightly on the enamel surfaces. Between the peritubular and the intertubular dentin, there appeared a distinct difference in the dissolved area. The laser almost completely removed carious regions of the enamel and the dentin, and penetration extended beyond the carious regions. In the backscattered electron SEM, highly mineralized layers were observed on the enamel and dentin surfaces dissolved by the laser. © 1993 Wiley‐Liss, Inc.
Preliminary analysis of histological results of Hexascan™ device with continuous tunable dye laser at 514 (argon) and 577 NM (yellow)
Authors: Apfelberg David B. , Smoller Bruce 
Published: March 2007

AbstractThis histological study demonstrates that the Hexascan™ device combined with a continuous tunable dye laser at either 514 nm or 577 nm is able to effectively treat port wine hemangiomas. Both 514 nm and 577 nm were effective in producing almost normal looking skin histologically after treatment in some patients. Other patients demonstrated a minor number of residual vessels or no significant change. In this small series, it appeared that the 514 nm and 577 nm wavelengths were similar histologically. © 1993 Wiley‐Liss, Inc.
Pulsed dye laser treatment of recalcitrant verrucae: A preliminary report
Authors: Tan O. T. , Hurwitz R. M. , Stafford T. J. 
Published: March 2007

AbstractPatients with recalcitrant warts on the fingers and hands, periungual, and other parts of the body including verrucae plana and plantar surfaces were treated using the pulsed dye laser at 585 nm, 450 usec, and a spotsize of 5 mm diameter. Of the 39 patients treated, 28 (72%) were cleared of their warts after an average of 1.68 treatments at fluences of 6.25–7.5 J/cm2. Seven (18%) patients had a reduction of between 80–95% of their warts after 1.3 treatments, and verrucae reduced by 50% in four of the 39 patients after one treatment. The average follow‐up period of the 28 cases cleared of their warts has been 5 months. Of this group, those with periungual warts have been followed for up to 6.4 months, compared to 4.8 months for those with warts on other parts of their body, 4.0 months for those with finger and hand warts, and 2.0 months for plantar warts. Only one of the 28 patients has had a recurrence after 3 months of clearance. © 1993 Wiley‐Liss, Inc.
Preliminary experience with transluminal laser–induced intrahepatic portacaval shunts
Authors: Cikrit Dolores F. , Wadley J. Jeffrey , Harl Michael J. , Heller Sherry A. , Dalsing Michael C. 
Published: March 2007

AbstractThis study investigated the feasibility of performing an intrahepatic portacaval shunt (IHPCS) by means of transluminal laser angioplasty. In 10 anesthized dogs, a catheter was introduced into a mesenteric vein and threaded into the portal vein (PV). Under fluoroscopy, a Ross needle was passed through the PV catheter, liver, and into the intrahepatic IVC. Following guidewire exchange, a neodymium YAG laser hot‐tip probe (power setting 8 W) was passed over the guidewire to accomplish a transluminal IHPCS. In five animals, an IHPCS could not be accomplished. Initial and subsequent patency was confirmed by fluoroscopy. These early data suggest that transvenous laser‐in‐duced intrahepatic portacaval shunts may be feasible as a means of decompressing portal hypertension. Further research is necessary to investigate the long‐term patency as well as this technique's ability to decompress the portal system. © 1993 Wiley‐Liss, Inc.
Modeling the color perception of port wine stains and its relation to the depth of laser coagulated blood vessels
Authors: Lakmaker Olof , Pickering John W. , van Gemert Martin J. C. 
Published: March 2007

AbstractTo find the maximal depth of an ectatic vessel in the dermis that contributes to the abnormal color of a port wine stain (PWS), “normal” and “laser treated PWS skin” are modeled, respectively, as a two‐layer plane parallel geometry consisting of an epidermis and a dermis, and as a three‐layer geometry consisting of an epidermis, a dermis without additional blood (the “treated” part of the stain, assumed identical to the “normal” dermis), and a layer of dermis containing 5% or 10% of blood per volume (the untreated part of the PWS). Spectral remittances were calculated for various wavelengths using the diffusion approximation to the transport equation for light propagation. These remittances were transformed into the CIE 1976 (L*a*b*)‐color system. Color differences between “normal” and PWS skin as a function of the dermal depth of “injured” ectatic blood vessels were calculated. The maximal depth where ectatic blood vessels just contribute to the abnormal PWS color is predicted as 0.9 mm for a “normally” pigmented epidermis (60 μm thick) and a 5% or 10% blood per volume content. For a darker pigmented epidermis (60 μm thickness) and again at both 5% and 10% blood per volume content, this depth was found to be 0.8 mm. © 1993 Wiley‐Liss, Inc.