bluuebunny/crossref_metadata_2025 huggingface dataset:
carbon dioxide surgical laser in neurological surgery, decubitus ulcers, and burns
Authors: Stellar Stanley
Published: March 2007

Laser surgery has become an established part of general and specialty surgical techniques. Of all the lasers available today, the carbon dioxide laser possesses the physical and biological‐surgical properties of most value to the surgeon. The CO2 laser puts out a spatially and temporally coherent beam of high intensity, infrared radiation at 10.6 μm, a wavelength nearly 100% absorbed by tissue. Its action is dependent on heat, and it has the ability to vaporize, cut, and excise all tissue hemostatically, sterilizing as it proceeds. Experimental work in animal patients and man has laid the groundwork for clinical application.

The CO2 laser's value as a surgical tool has been clearly shown in the treatment of cancers and other neoplasms in brain, thoracic, and abdominal viscera; larynx; pharynx; nasal and sinus cavities; rectum; vulva, vagina; and uterus, for palliation and, at times, cure. It has been found of undoubted value in the debridement of decubitus ulcers and burns and has great potential for orthopedic surgery and breast surgery.

The surgical laser is safe for patient and operating personnel, relatively simple to use, rapid in its action and without untoward impact on tissue locally or at a distance.
Carbon dioxide laser therapy of cervical intraepithelial neoplasia: Factors determining success rate
Authors: Burke Louis , Covell Linda , Antonioli Donald
Published: March 2007

Sixty patients with biopsy proven CIN were treated with CO2 laser. Severity of the lesion was equally divided among all three grades of CIN. All patients were biopsied immediately after laser therapy and at six and twelve weeks past treatment. Persistence or absence of disease was evaluated with respect to severity of disease, size of lesion, method of applying laser, whether the endocervical canal was involved, whether only the lesion or the entire transformation zone was lasered, and depth of laser effect. The persistence of disease was 36.7 percent after therapy. Success was not related to severity of disease, size of lesion, or whether the endocervical canal was involved. It was related to depth of coagulation necrosis, method of applying the laser beam, and if the entire transformation zone was treated.
Clinical experience in the laser therapy of port wine stains
Authors: Cosman Bard
Published: March 2007

Experience in the setting up of a laser facility for the treatment of port wine stains is presented. Clinical material relative to the natural history of the port wine stain lesion is discussed. Results obtained in 202 patients treated with the argon laser are studied and photographic results presented. Methods of clinical evaluation are offered. Clinical parameters affecting results are identified. The relationship between test spot results and treatment areas is demonstrated. Treatment strategy is mentioned. The argon laser therapy of port wine stains is a valid technique justifying further work to establish age limits and other clinical features which may affect results.
Argon laser iridotomy in primary angle‐closure or pupillary block glaucoma
Authors: Schwartz Louis W. , Spaeth George L.
Published: March 2007

This paper describes the use of a pulsed argon laser to perform iridotomies in 87 patients. Diagnoses include: primary angle closure glaucoma, narrow angle in the fellow eye of patients with primary angle closure glaucoma, pupillary block, and after incomplete surgical iridectomies. Laser iridotomy was achieved in 79% of patients. Blue eyes were slightly more difficult to penetrate. Success was almost 100% in those with pupillary block. Penetration was most difficult in patients with primary angle closure glaucoma (64%), but more easily accomplished in the fellow eyes of such cases (87%). In 13 patients surgical peripheral iridectomy was performed on one eye while the other eye was treated with laser iridotomy. No apparent significant long term differences were noted between the two eyes of the same individual. Complications of laser iridotomy include corneal burns, pupil distortion, synechia formation, lenticular opacities, iritis, marked pigment dispersion, sudden rise in intraocular pressure, and retinal burns. At this time a longer follow‐up is required before it can be stated that a laser PI is more advantageous than a surgical PI. However, the laser's simplicity and ease of administration appear to warrant its continued use at this time.
Results and Complications of Limbal Trephination and Subscleral Trephination (Trabeculectomy)
Authors: Saul Sugar H.
Published: March 2007

Limbal trephinations on 395 eyes were followed postoperatively for six months to 19 years. Excellent results were obtained in patients over the age of 35, particularly those in the 50 and older age group, with chronic open‐angle and chronic angle‐closure glaucoma. Results were poor in younger age groups and in those with secondary glaucoma, particularly where it was associated with inflammatory disease.

A review of 78 limbal trephinations in individuals over 55 and 77 trabeculectomies (67 under age 55 and ten over age 55) indicated that in younger age groups the overall results were nearly the same with trabeculectomies as with limbal trephination but that the subscleral operation is probably safer, especially in younger people with longer life expectancy, and permits freer use of contact lenses postoperatively.
Laser Vaporization on Intracranial Tumors
Authors: Gong‐Bai Chen
Published: March 2007

Brain tumors can be treated with the laser. The CO2 laser may be used in several ways. Massive or well‐encapsulated tumors may be removed in the usual way and the remnant vaporized by the laser from the depth, dura, or cranium. If the tumor is superficial and not massive, it may be vaporized with the laser immediately.

Deep‐seated tumors may be exposed by incising the overlying cortex with a focused laser beam and the tumor then treated by conventional means or with the laser or both.

Cystic tumors must be aspirated and then the laser used to vaporize the cyst wall. Wet cotton pads should be used to protect the brain. The experience with nine brain tumors is reported, pointing out advantages and disadvantages of the laser. A 300 watt CO2 was used for treatment. Measurement of the temperature of the brain 0.5 cm. from the point of vaporization is reported.
Stimulatory Effect of Laser on the Physiological Healing Process of Portio Surface
Authors: Kovács Lajos
Published: March 2007

Injuries of the cervix lead to ectopion and erosion. The alkaline secretion of this ectopic epithelium is irritating. Therepy is directed toward acceleration of the healing process. Caustics, vaginal irrigation, and cautery have given less than desirable results. A simple, inexpensive, painless method not requiring hospitalization or loss of time from work is treatment with the helium neon laser. It stimulates growth of connective tissue and allows epitheliasation to take place. The method and results are discussed.
Theoretical and Experimental Investigations Prove Nd: YAG Laser Treatment to Be Safe
Authors: Halldórsson T H. , Rother W. , Langerholc J. , Frank F.
Published: March 2007

The safety of the application of the Nd:YAG laser for hemostasis in emergency gastro‐endoscopy when its irradiation is properly dosed is demonstrated on the basis of laboratory investigations as well as theoretical calculations on a mathematical model of internal scattering. The increased effectiveness of this laser compared with argon and CO2 lasers in producing in‐depth volume heating is shown to derive from the fortuitous combination of its low absorptivity with the scattering phenomenon.
China report. II. Laser medicine in the People's Republic of China
Authors: Jianan Qin , Bingrong Liu
Published: March 2007

The application of lasers to medicine in the People's Republic of China allready has an history of more than fifteen years. Lasers are being used in various clinical departments such as ophthalomology, dermatology, otorhinolaryngology, surgery, obstetrics, gynecology, neurology, psychiatry, internal medicine, and acupuncture. A brief account of basic research and instrumentation is also presented. The academic activities of laser medicine in China are increasing repidly, and sugestions for the establishment of a Chinese Laser Medical Society have been proposed. The prospectives for laser medicine appear brilliant and promising.
Laser medicine in America: An overview
Authors: Goldman Leon
Published: March 2007

Laser medicine, as differentiated from laser surgery, has made tremendous progress in recent years. Laser diagnosis includes various laser techniques such as spectroscopy, Doppler velocimetry. and cytofluorometry, including cell sorter systems for current htbridima technology. In addition, there is laser induced fluorescence for cancer detection and treatment. Laser immunobiology includes laser nephelometry. Laser acoustical microscopy and laser transillumination for cancer diagnosis are also a part of current laser medicine, which offers much for cancer research, diagnosis, and treatment.
the use of lasers in hemangiomas
Authors: Aronoff Billie L.
Published: March 2007

Vast experience with hemangiomas has allowed us to categorize those that could be treated with the CO2 or argon laser. Certain types will be contraindicated for laser surgery as they are very difficult to remove with present techniques.
The treatment of vascular malformation of the brain with laser source
Authors: Fasano V. A.
Published: March 2007

The first three cases of vascular malformations in humans (two artero‐venous aneurysms and one saccular aneyrysm) treated with the association of CO2 laser and Neodymium: Yag lasers, are presented here. The post‐operative course has been very good. However, it is still necessary to examine a larger number of cases to see if, how, and when this treatment can be utalized in place of traditional methods.
The effect of laser osteotomy on bone healing
Authors: Gertzbein S. D. , Dedemeter D. , Cruickshank B. , Kapasouri A.
Published: March 2007

Osteotomy of the rat femur performed by the laser was compared to osteotomty made by a hand‐saw cut. It was noted that, radiographically and histologically, there was a delay in healing in the laser group, but biomechanical testing failed to reveal any significant difference in bone strength.
Preliminary report on the application of the CO2 laser scalpel for operations on the maxillo‐facial bones
Authors: Pao‐Chang Ma , Xiou‐qi Xu , Hui Zhou , Zheng Liou , Peng Zhuo Rui
Published: March 2007

In surgery about the face, it is frequently necessary to remove part of the bones. The CO2 laser is efficient in cutting out desired areas with the ability to leave unfractured bone behind. Because of the intense heat, one must realize the extent of bone injury and know about delayed healing. Suggestions for minimizing the injury are included.
Port wine stain coagulation experiments with a 540‐nm continuous wave dye‐lase
Authors: Hulsbergen Henning J.P. , Van Gemert M.J.C.
Published: March 2007

Treatment of port wine stains with a continuous wave dye laser at 540 nm was performed in three patients. Coagulation of the capillary blood plexus without damaging the epidermis and superficial dermis was shown to be possible for laser energy densities between 5 J/cm2 and 6.5 J/cm2. Vascular destruction was realised up to about 0.3 mm dermal depth. After 5 months the skin was perfectly normal. A comparison with argon laser treatment was made.
Rhinophyma treated by argon laser
Authors: Hulsbergen Henning J.P. , Van PhD M.J.C. Gemert
Published: March 2007

Results are reported of rhinophyma treated by argon laser. The therapy is assumed to be based on two features: first, selective coagulation of the blood capillaries which cause redness of the nose and which feed the hypertrophic regions; second, direct coagulation shrinkage of the hypertrophic connective tissue. The therapy is simple, causes no noticeable discomfort, requires no (local) anaesthesia or admission, and can be performed more than once. Thirteen patients were treated, eleven men and two women. Systemic treatment could be stopped in all but one case (seven patients). Two out of ten patients still use resorcinol but at a reduced freqency. The general result is a smooth and more natural appearance of the nose without redness. Pustulosis has become an exception.
Cell biology of hematoporphyrin derivative (hpd)
Authors: Berns Michael W. , Wilson Marie , Burns Robert , Berns Michael W. , Wile Alan , Rentzepis Peter
Published: March 2007

Tissue culture cells were treated with hematoporphyrin derivative (HPD) and analyzed for (1) HPD uptake, (2) HPD washout, and (3) fluorescence changes. The absorption peaks were the same for HPD in solution and HPD bound to cells. HPD was taken up by all cell types rapidly within the first 10 hours of exposure, and leveled off by 20 hours of exposure. HPD came out of all cell types to control levels by 72 hours after removal of the HPD bathing solution. The HPD appeared to come out of the malignant 3‐T‐12 cells more slowly than from the parental (non‐malignant) 3‐T‐3 cells. The fluorescence spectrum of HPD‐treated cells changed markedly from the time that the bathing HPD solution was removed from the cells. As time progressed the weakly fluorescent 590‐nm peak increased greatly and the 615‐nm and 630‐nm peaks decreased significantly.
Effects of low‐level energy lasers on the healing of full‐thickness skin defects
Authors: Surinchak John S. , Alago Maria L. , Bellamy Ronald F. , Stuck Bruce E. , Belkin Michael
Published: March 2007

Effects of low‐level helium‐neon laser radiation were compared on (1) wounds that closed primarily by contraction and (2) the breaking strength of straight‐line incisions. Circular full‐thickness skin defects in rabbits received dosages of 1.1 J/cm2 during a 30‐min exposure every third day, and 2.2 J/cm2 during a 3‐min exposure twice daily until wound closure. No significant differences in healing were observed between laser‐treated wounds and untreated control wounds. Conversely, rat skin incisions exposed to 2.2 J/cm2 for 3 min twice daily for 14 days demonstrated a 55% increase in breaking strength over control rats (p <0.01); 28 days postoperatively, this difference in breaking strength diminished to a nonsignificant 16% increase over the control rats. Increasing the dosage to 4.5 J/cm2yielded a nonsignificant 17% increase over the control rats 14 days postoperatively. HeNe laser irradiation of wounds increases certain aspects of healing in the early stages, but not to such a degree as to be clinically applicable. More detailed research is indicated to obtain optimal exposure levels necessary to accelerate wound healing significantly.
Noninvasive assessment of microcirculation of living organs and tissues using laser
Authors: Kamada Takenobu , Sato Nobuhiro , Kakubari Naomichi , Yoda Kiyoshi , Kawano Sunao , Schichiri Motoaki , Abe Hiroshi
Published: March 2007

For studying microcirculation of intact tissues or organs, a new noninvasive, heat‐transient method using laser photoexcitation is described. As a heating source an argon ion laser or R6G dye laser was used via a quartz fiber optic guide. Infrared radiation from heated tissue was detected by a thermography apparatus. After switching the laser irradiation on and off, a thermal transient curve of a model tissue, the skin, was biphasic: a component with a fast time constant and the other with a slow time constant. The temperature increases of both phases following laser irradiation were linear to the applied power from the laser onto the tissue. The temperature rises as a function of the wavelength of irradiated light have shown that the absorption of the light by tissue hemoglobin is a main heat‐generation source. Furthermore, the temperature rises as a function of tissue blood volume and flow have shown that the component with a slow time constant is more related to the tissue hemoglobin concentration and tissue blood flow and heat conductivity. Thus, the analysis of heat‐transient curves following laser irradiation gives information as to regional tissue blood volume, blood flow, and tissue heat conductivity.
CO2 lasers: Beam patterns in relation to surgical use
Authors: Fava G. , Emanuelli H. , Cascinelli N. , Bandieramonte G. , Canestri F. , Marchesini R.
Published: March 2007

According to surgeons operating with a variety of CO2 lasers available at the National Cancer Institute of Milan (Coherent, Sharplan, Valfivre), these lasers have different cutting and coagulation properties.

To identify what physical parameters might corroborate the subjective impression of the surgeons, a comparative study of the crater forms in perspex samples was performed. Perspex was chosen for its thermal properties (in fact, its thermal conductivity and diffusivity are similar to those of organic tissue) and because it allowed good visualization and measurement of crater characteristics.

Depth of penetration, crater diameter, and extension of thermal damage were measured against power, focal length, and exposure time for each CO2 laser model. These results can be used as an index of behaviour of different surgical lasers.

It appears that for fully characterizing the interaction of surgical lasers with the sample, it is necessary to specify either power, focal length, exposure time, or beam mode.
Linear and nonlinear effect of the argon laser on a fallopian tube animal model
Authors: Bellina Joseph H. , Ross Lynne Fischer , Holmquist Nelson , Voros Janos I. , Moorehead Myron E.
Published: March 2007

Rabbit fallopian tubes were used as models to demonstrate the delayed effects of the argon laser wavelength on tissue. Power density, energy density, and velocity were all variables in the experiment. Three groups of ten rabbits were sacrificed two at a time, on days 0, 5, 10, 15, and 20. The results clearly showed delayed tissue changes associated with fibrosis. Mathematical and theoretical comparisons of the argon laser to the carbon dioxide laser help express the advantages and disadvantages of the use of the argon laser in fallopian tube surgery. The return of organ function with respect to time has possible significance to studies of human fallopian tube surgeries.
Analysis of complications of argon laser treatment for port wine hemangiomas with reference to striped technique
Authors: Apfelberg David B. , Flores Jasmin T. , Maser Morton R. , Lash Harvey
Published: March 2007

Argon laser treatment of port wine hemangiomas has evolved greatly in technique. Since 1979, we have treated 150 patients with the “zebra strike” technique in order to enhance fading and lessen the incidence of complications or side effects. Eighty‐one such patients are studied in depth with at least an 18‐month follow‐up on all patients. The “zebra stripe” technique is described in detail. Analysis of fading shows a 64% excellent or good result in all patients and analysis of sponginess shows that a marked reduction of sponginess is possible by the laser. Side effects and complications including hypopigmentation, texture change, and indentation are discussed in detail. Analysis of scarring shows an overall scar rate of 15% with a general scar rate of 7.4% if you exclude the lip and nasolabial area. Residual striping was present to a slight degree in 34% of the patients and to a major degree in 7% of the patients. All factors are discussed as far as age, complexion, sex, color or port wine stain and related to stripe technique.
Laser oncology in Italy: experimental research and clinical applications at the National Cancer Institute, Milan
Authors: Emanuelli H. , Bandieramonte G. , Marchesini R. , Fava G. , Rodari A. , Colombo M. P. , Costa A. , Spinelli P. , Zunino F. , Chiesa F. , Cascinelli N. , Andreola S. , Pariente R. , Canti G. F.
Published: March 2007

CO2, Nd:YAG, and argon lasers have been used for 5 years for experimental and clinical procedures at the National Cancer Institute of Milan under the auspices of the National Research Council. Experimental data regarding tumor cell spread through lymphatic and hematic channels and cell viability in the fumes after CO2laser irradiation are reported. New advantages in the combined treatment modalities have been demonstrated, since the synergism between the low power argon laser beam and chemotherapeutic agents (anthracyclines) was assessed on cell cultures and the least toxic and the most effective doses of the drugs were identified. Due to the optical properties of the laser beam, physical measurements of the delivered energy and mathematical calculation of the energy per tissue volume unit to be ablated increase the precision in microsurgery especially when conservative managements are indicated. Main applications in surgical oncology, and comparison versus conventional methods, both with vaporization and excisional techniques, according to specific therapeutic protocols, in general surgery, otolaryngology, gynecology, and endoscopy, even on an outpatient basis, are finally illustrated in a series of 600 cases.
Effects of Laser Sources (Argon, Nd:YAG, CO2) on the Elastic Resistance of the Vessel Wall: Histological and Physical Study
Authors: Fasano V. A. , Ponzio R. M. , Benech F. , Sicuro M.
Published: March 2007

The function of elastic elements of the vessel wall is to produce a tension suitable to resist the distension strength made by blood pressure. By producing a modification in the morphologic and structural configuration of such elastic elements, it is possible to obtain changes of the elastic resistance of the wall. The paper reports the histological and physical modifications of blood vessel walls irradiated with different laser sources.
Is Closure of Open Skin Wounds in Rats Accelerated by Argon Laser Exposure?
Authors: Jongsma F. H. M. , Bogaard A. E. J. M. v. D. , Van Gemert M. J. C. , Hulsbergen Henning J. P.
Published: March 2007

The influence of linearly polarized argon laser irradiation (λ = 488 nm and 514.5 nm) on the closure time of standardized open skin wounds was measured in rats. In two separate controlled experiments no acceleration of wound closure by laser irradiation was observed. In the first experiment the wounds were cleaned during the laser treatment period at 1 J/cm2. The second experiment at 4 J/cm2was without mechanical wound cleaning. The contradictory results reported in the literature and possible influences of wavelength, energy density, and power density are discussed.
Hepatic Resection With an Nd.YAG Laser in Pig
Authors: Godlewskis G. , Ginoves P. , Chincholles J. M. , Viel E. , Bureau J. P. , Rouy S. , Mion H. , Dubois A. , Fesquet J.
Published: March 2007

Eleven hepatic resections were performed by means of a divergent Nd:YAG laser. The beam was transmitted through a fiberoptic delivery system without any handpiece. The shortest resection time and most limited ischemic damage (4 mm) were obtained with 80‐W power shoots and a low divergent beam (4°2 for full angle). The hemostatic effects of the NdrYAG controled bleeding from veins of up to 4.5 mm in diameter, and parenchymatic oozing from the cut edge minimized blood loss. Histological examination revealed the importance of cellular deterioration in the ischemic layer, while electron microscopy showed selective destruction of cell organelles and protein denaturation. Marked elevation of hepatic serum enzymes suggests a high degree of cellular damage. Postoperative examinations confirmed an uncomplicated healing process. Finally, the use of a flexible fiberoptic enables easy surgical manipulation.
Neodymium:YAG Laser in the Treatment of Gynecologic Malignancies
Authors: Schellhas Helmut F. , Weppelmann Burhkard
Published: March 2007

The Nd:YAG laser has been used for tumor volume reduction of recurrent gynecologic malignant tumors after previous radiation therapy. The localization of the tumor did not allow conventional surgical resection or surgery was contra‐indicated because of severe medical problems. Hemorrhage caused by recurrent tumor was controlled by tissue coagulation. The laser beam was delivered by means of a handpiece using the Model 8000 of the Molectron Medical Corporation. A power of 40 to 100 W was used with the maximal pulse duration of 9.9 sec and multiple pulse irradiation. The total energy ranged between 620 and 13.105 Ws. Good palliation was achieved in patients with hemorrhaging tumors of the cervix and ovary metastatic to the vagina.
Myocardial Revascularization by Laser: A Clinical Report
Authors: Mirhoseini M. , Fisher J. C. , Cayton M.
Published: March 2007

Methods used to revascularize ischemic myocardium have included arterial reconstruction, coronary artery bypass grafting, providing direct circulation from the intraventricular chamber, and techniques to promote collateral circulation.

Ventricular channels from the epicardial surface through the endocardium are readily made with the CO2 laser. Animal experiments suggest that these channels protect the ischemic myocardium and provide circulation to the muscle from the ventricular chamber.

Clinical use of the CO2 laser in conjunction with aortocoronary bypass grafting is reported in a patient with three‐vessel coronary artery disease and total occlusion of the left anterior descending coronary artery (LAD), and hypokinesis of the anterior wall and apex. Following bypass a series of laser channels were made in the hypokinetic area of the left ventricle. Postoperative myocardial Tc PYP scans were within normal limits, including the previously dyskinetic anterior apical area. Serial EKGs remained unchanged from the preoperative status. Creatinine phosphokinase‐myocardial band (CPK‐MB) was elevated to 6 on the first and second postop day and was 0 from the third day. The patient was not recatheterized.

The technique of myocardial revascularization by laser may be a viable addition to present treatment modalities. Further investigation and long‐term follow‐up are needed.
Laser photoradiation therapy of cancer: An update of the experience at the university of California, Irvine
Authors: Wile A. G. , Coffey J. , Nahabedian M. Y. , Baghdassarian R. , Mason G. R. , Berns M. W.
Published: March 2007

This update of the experience at the University of California at Irvine with laser photoradiation therapy (PRT) encompasses the period between May 1981 and June 1983. The results of treatment of 77 patients are reported (head and neck, 39; breast, 33, and lung 5). Head and neck cancer patients received treatment to 114 sites with a complete response (CR) in 28, partial response (PR) in 42, stable disease (SD) in three, and no response (NR) in 34, and an undetermined response in seven. Breast cancer patients were treated in 395 sites with CR in 222, PR in 74, SD in one, NR in 92, and undetermined response in six. The lung cancer patients in this series responded poorly, if at all.

In addition to the above patient trials, we have investigated the interaction to laser hematoporphyrin derivative (HPD)‐ PRT with a chemotherapeutic agent, Cisplatin, against an experimental tumor (RIF‐1) in an animal model. We have been unable to demonstrate an additive effect of laser HPD‐PRT at total light doses of 25 j/cm2and 75j/cm2 with Cisplatin at a dose of 7 mg/kg. However, no additional toxicity was observed on combination therapy, suggesting that sequential application of laser HPD‐PRT and Cisplatin may be safely employed in clinical situation.

Another area of investigation has been the evaluation of the light‐scattering characteristics of a lipid emulsion designed for laser HPD‐PRT of bladder tumors. We have demonstrated that it is feasible to gain uniform illumination of the bladder surface with the use of this light‐dispersing medium. We now believe that it is appropriate to begin clinical trials in which laser HPD‐PRT is utilized as the initial form of therapy. Sites that appear most appropriate for this therapy are early cancers of the head and neck and early cancer of the bladder.
Application of hematoporphyrin derivative and laser‐induced photodynamical reaction in the treatment of lung cancer: A preliminary report on 21 cases
Authors: Li Jun‐Heng , Zhao Shu‐De , Song Shou‐Zhong , Chen Yu‐Ping , Zhang Li‐Tian
Published: March 2007

This paper reports results of hematoporphyrin derivative based on photodynamic therapy (PDT) of 24 lung cancer lesions in 21 patients that were followed at least three months. Three if 24 lesions exhibited complete remission and 20 of 24 exhibited a response to PDT. Tumors in twenty of twenty‐one patients exhibited visually disceRNible hematoporphyrin derivative fluorescence upon irradiation with the 514‐nm line from an argon ion laser.

There were no severe complication due to PDT. The hematoporphyrin derivative, argon ion laser pumped dye laser (rhodamine B) system, and quartz fiber we used in this clinical series were all made in the People's Republic of China.
Clinical measurement of tumor fluorescence using a new diagnostic system with hematoporphyrin derivative, laser photoradiation, and a spectroscope
Authors: Kato Harubumi , Ono Jutaro , Konaka Chimori , Kawate Norihiko , Yoneyama Kazuo , Kinoshita Komei , Nishimiya Katsuaki , Sakai Harumasa , Noguchi Masayuki , Tomono Takahisa , Hayata Yoshihiro , Aizawa Katsuo , Kawasaki Satoru , Tokuda Yasuaki
Published: March 2007

Hematoporphyrin derivative (HPD) is retained by malignant tumors and emits fluorescence with peaks of 630 and 690 nm wavelength when HPD is exposed to light. It is therefore theoretically possible to make a diagnosis of malignant tumors by detecting the fluorescence of HPD. The authors developed a spectroscope system compatible with fiberoptic endoscopes to analyze the shape of the fluorescence light spectrum. We could clearly recognize the HPD‐specific fluorescence in human cancer foci. This system can be applied to the measurement of the relative amount of HPD absorbed in superficial tumor tissue before the photodynamic therapy. This might suggest the extent of tumor. The clinical diagnostic applications of this system are described in this study.
Evaluation of hematoporphyrin photoradiation therapy to treat choroidal melanomas
Authors: Bruce Robert A.
Published: March 2007

Hematoporphyrin derivative‐photoradiation therapy (HPD‐PRT) was used to treat choroidal melanomas in 23 human subjects. Tumor sizes were divided into three categories: less than 500 mm3 (11 patients), 500‐1,000 mm3 (four patients), and greater than 1,000 mm3 (eight patients). Tumors were exposed to 630 nm laser light at total doses of 300‐3,000 J/cm2. Significant tumor reduction was noted in the subjects with initial tumor volume of less than 500 mm3 and 500‐1,000 mm3.
Evaluation of visual acuity during laser photoradiation therapy of cancer
Authors: Coffey J. H. , Wile A. G. , Mason G. R. , Berns M. W. , Mosier M. A.
Published: March 2007

Visual function for ten patients undergoing HPD‐PRT was tested using 1) the Graham Filed Eye Chart for distance vision, 2) pseudo‐isocharomatic plates for color vision, and 3) Amsler grid for changes in macular function. Whereas some increases and decreases in ocular function were observed, no clear patteRNs or changes of significance were observed.
Laser photoradiation therapy of cancer: Possible role of hyperthermia
Authors: Berns Michael W. , Coffey Joan , Wile Alan G.
Published: March 2007

Two patients were treated at 20 different tumor sites by hematoporphyrin derivative (HPD) photoradiation therapy (PRT). An infrared detector was used to record changes in surface temperature during laser exposure. A temperature rise of up to 4.9 °C was recorded for a total energy of 15–30 J/cm2 and less than 150 mW/cm2. For 508 mW/cm2 and 15–20 J/cm2 a temperature rise of 7.0 °C was detected. The results suggest a possible role of hyperthermia in HPD‐PRT.
Interstitial applications of laser irradiation in hematoporphyrin derivative photosensitized dunning R3327 prostate cancers
Authors: McPhee M. S. , Thorndyke C. W. , Thomas G. , Chapman D. , Lakey W. H. , Tulip J.
Published: March 2007

Two prostate tumour models (Dunning R3327H and AT) were tested in rats to see if they were sensitive to hematoporphyrin‐photoradiation therapy (HPD‐PRT). The R3327H tumours were irradiated by implantation of a single fiber optic and the R3327 AT tumours were treated with implantation of four fiber optics simultaneously. Thermal measurements made at the tip of the fiber and up to 1 cm from the tip indicated temperature rises from 1.5 °C to 20 °C at the tip and 0 ° to 8 °C distal to the tip, with power densities ranging from 100 mW to 500 mW. The R3327H tumour was controlled up to 8 weeks post‐HPD‐PRT, when the initial tumour size was 400–500 mm3. The R3327 AT tumours also respond to the HPD‐PRT but a significant laser‐induced thermal rise in the tumour is suspected.
Hematoporphyrin derivative photoradiation therapy of the rat 9L gliosarcoma brain tumor model
Authors: Boggan James E. , Edwards Michael S. B. , Bolger Catherine A. , Berns Michael W. , Walter Robert J.
Published: March 2007

The distribution of hematoporphyrin derivative (HPD) in the rat 9L gliosarcoma intracerebral brain tumor model at 4, 24, 48, and 72 hours after intravenous administration was evaluated using a digital video fluorescence microscopy technique. Maximum tissue fluorescence in the normal brain was observed at 4 hours, whereas maximum fluorescence in the tumor regions occurred at 24 hours. Although the fluorescence counts suggested that there was significant uptake of HPD within the tumors when compared to normal brain, only 33% to 44% of each of the eight tumors surveyed showed fluorescence.

In response to a laser light dose (633 nm) of 30 J/cm2, six rats that had been sensitized with HPD had a patchy coagulation necrosis involving up to 70% of the total tumor volume. In contrast, four rats given HPD only or exposed to laser only had no areas of necrosis, as observed on histological examination. In a group of 30 rats, no prolongation of survival was observed in response to photoradiation therapy.
Laser‐welded vs soldered nonprecious alloy dental bridges: A comparative study
Authors: Apotheker Harvey , Nishimura Ichiro , Seerattan Carl
Published: March 2007

The high cost of gold alloy has caused the dental profession to begin substituting nonprecious alloy for the framework in porcelain fused to metal bridges. Especially in long‐span bridges it may be advantageous to make multiple castings and then join them for a better fit. As opposed to the highly successful soldering of gold, soldered nonprecious alloy bridges have a great failure rate in the mouth. Removal of and remaking of the bridges is thus the result. This study compares nonprecious units that have been laser‐welded with those conventionally soldered. Seven identical bridges of three units were cast in a popular alloy composed of 74–78% nickel, 12–15% chromium, 4–6% molybdenum, and 1·8% maximum beryllium. One served as a control, while the remaining six were all cut in the same place. Of these, three were soldered with a gas oxygen torch. The other three were welded with a Nd‐YAG laser. Better and stronger joints unlikely to fracture in the mouth were found with the leser‐welded specimen.
Adhesion of composite materials to enamel: Comparison between the use of acid and lasing as pretreatment
Authors: Liberman R. , Segal T. H. , Nordenberg D. , Serebro L. I.
Published: March 2007

Acid‐etch is presently the accepted method for adhesion of composite materials to enamel. In this investigation, we used the laser for pretreatment of the enamel instead of acid. The adhesive (tensile) strength was measured by the Instron unit and statistically analyzed.

Results demonstrated that bonding strength following laser pretreatment is comparable to that of acid‐etch.
Laser recannalization of atheromatous vessels using fiber optics
Authors: Ward H.
Published: March 2007

A laser endoscope was devised using optic fibers in order to provide a means of visualization and removal of atheromatous plaques from arteries in cadavers and experimental animals. Atheromatous plaques were satisfactorily lased off in a few seconds, although contraction of lased vessels was observed. A self‐focusing fiber was shown to provide laser access to and visualization of the body via a single optic fiber of feasibly less than 0.2 mm diameter.
Clinical and histological evaluation of portwine stain treatment with a microsecond‐pulsed dye‐laser at 577 NM
Authors: Henning J. P. Hulsbergen , van Gemert M. J. C. , Lahaye C. T. W.
Published: March 2007

Test treatment of portwine stains (PWS) was performed with a microsecond‐pulsed dye laser at 577nm using a 2‐mm spot diameter. Although selective coagulation of the erythrocytes occurred, this did not result in bleaching of the treated area. Massive destruction of the dilated capillaries is suggested to be a prerequisite for PWS‐bleaching, very probably requiring msec (instead of μsec) laser pulses.
Extensive granuloma pyogenicum as a complication of endolaryngeal argon laser surgery
Authors: Dejonckere P. H. , Franceschi D. , Scholtès J. L.
Published: March 2007

A case report of an exuberant anterior transglottic granuloma pyogenicum as a complication of endoscopic argon laser surgery for an anterior web, after previous treatments of juvenile laryngeal papillomatosis, is described.
Potentiation of photodynamic therapy by heat: Effect of sequence and time interval between treatments in vivo
Authors: Waldow Stephen M. , Henderson Barbara W. , Dougherty Thomas J.
Published: March 2007

Photodynamic therapy (PDT) utilizing hematoporphyrin derivative (Hpd) as photosensitizer and an argon‐dye laser as the light source was used alone and in combination with a localized microwave hyperthermia treatment to treat the SMTF mammary carcinoma in mice. A 30‐min heat treatment at 44.5°C was applied 0–8 hr before or after a standard photodynamic treatment (67.5 or 135 J/cm2, given 24 hr post‐7.5 mg/kg Hpd). Potentiation of PDT by heat was found to be related to the sequence of the treatments and the time interval between them.

When 44.5°C for 30 min was applied immediately after a 15‐min PDT treatment, significant potentiation was seen (58% long‐term tumor control vs 3 and 10%, respectively, for PDT and heat alone). This potentiation decreased with increasing time between PDT and heat, with tumor control values decreasing to 36, 20, and 14%, when 2, 4, and 8 hr, respectively, were allowed between treatments. Only additive effects of the independent therapies were found when this heat treatment was applied 0–8 hr before PDT.

In other experiments, mice were treated with single or fractionated 30‐min PDT treatments (two 15‐min treatments separated by 0‐,‐2‐, 4‐, or 8‐hr intervals). Decreases in tumor control were seen with increasing time interval; only minor differences in tumor control were seen when 4–8 hr was allowed between treatments compared to a single 15‐min treatment.
Modeling of (coronary) laser‐angioplasty
Authors: van Gemert Martin J. C. , Schets Gert A. C. M. , Stassen Edmond G. , Bonnier Johannes J.
Published: March 2007

A first attempt to describe (coronary) laser angioplasty is presented using simplified but standard optical and thermal modeling of tissue in interaction with a laser. Ablation behavior of blood thrombi and plaque has been approximated from numerical computations for various wavelengths representing the Ar, Nd‐YAG, and CO2 lasers. The overall results, in terms of calculated depth of ablation versus laser irradiation time, show a relatively fast initial process followed by a very slow one. The analysis suggests that a sequence of laser pulse‐catheter tip flushing should substantially increase the overall ablation velocity. The physics of threshold laser power and influence of laser beam diameter is discussed. A comparison between experimental results is made when possible. Suggestions for further test experiments are made.
Optical properties of human blood vessel wall and plaque
Authors: van Gemert Martin J. C. , Verdaasdonk Ruud , Stassen Edmond G. , Schets Gert A. C. M. , Gijsbers Geert H. M. , Bonnier Johannes J.
Published: March 2007

Optical properties of blood vessel wall and plaque from human cadaver material are presented for the argon laser (514.5 nm), He‐Ne laser (633 nm), and the Nd‐YAG laser (1,060 nm) wavelengths. Measurements were performed with an integrating sphere arrangement and anlayzed in terms of Kubelka‐Munk absorption and scattering coefficients.
Vascular recanalization with the argon laser: The role of blood in the transmission of laser energy
Authors: Kaplan Michael D. , Case Robert B. , Choy Daniel S. J.
Published: March 2007

Successful revascularization of stenosed arteries with the argon laser optical fiber catheter requires delivery of high‐power‐density energy to the lesion. Because of the high energy absorption by hemoglobin at the argon laser wavelengths, which would attenuate transmission of laser energy to the obstruction, we measured argon laser transmission through blood at different concentrations. We found that no transmission occurred through 1 mm of whole blood with hematocrit of 42 and that blood must be diluted to a hematocrit below 1 for laser energy to be delivered. Successful use of the intravascular argon laser is dependent on the creation of a transmission medium by displacement of blood by saline or other non‐absorbing substance.
Complete patency in thrombus‐occluded arteries two weeks after laser recanalization
Authors: Marco Jean , Silvernail Paul J. , Fournial Gerard , Choy Daniel S. J. , Fajadet Jean , Case Robert B.
Published: March 2007

The potential problem of rethrombosis after laser recanalization was studied in 16 thrombus‐occluded canine femoral arteries. Balloon de‐endothelialization and thrombin‐human blood injection produced adherent, completely occlusive thrombi 4.13 ± 1.54 cm in length; laser exposure of the thrombi occurred at 18.35 ± 22.1 hours. The argon laser catheter was introduced via a proximal arteriotomy and a power of 3.83 ± 0.58 W delivered for 411.3 ± 296.87 seconds. Follow‐up period was 14 days. All arteries were patent immediately after and 14 days following lasing, as demonstrated by angiography. There was no vessel perforation. Seven of the dogs were maintained on aspirin and dipyridamole 4 days before and throughout the study, but there were no differences in thrombus length, laser power, or duration of laser exposure between these dogs and those receiving no anti‐platelet therapy. Control thrombosed arteries (without laser energy application) showed no autolysis within 14 days in all dogs and up to 95 days in three dogs followed for this period of time.

These data show that rethrombosis of totally occluded, thrombosed arteries is not present up to 2 weeks later after laser recanalization, with or without the aid of anti‐platelet therapy.
Laser applications to arteriosclerosis: Angioplasty, angioscopy, and open endarterectomy
Authors: Eugene John , McColgan Stephen J. , Hammer‐Wilson Marie , Moore‐Jeffries Earl W. , Berns Michael W.
Published: March 2007

We have studied laser radiation of arteriosclerotic cardiovascular disease to determine the best technique for evaluation. Rabbits with arteriosclerosis were treated by intraluminal laser angioplasty (N = 8), laser angioscopy (N = 2), and open laser endarterectomy (N = 5). All studies were performed with an argon ion laser delivering energy through a 400‐μm quartz fiber. Power delivered was varied in order to determine the best value for this animal model. Following angioplasty, perforation was seen in three rabbits (in one case, it was due to mechanical trauma from the fiber optic), and early thrombosis occurred in two rabbits. Plaques were vaporized by angioscopy, but the depth of laser beam penetration or angle of incidence could not be controlled. Open laser endarterectomy gave consistently good results with removal of an arteriosclerotic plaque within the media. The optimum power was found to be 1.0‐2.0 W. Endarterectomy required an energy density of 100‐140 J/cm2. We conclude that open laser endarterectomy can be a standardized technique for the in vivo evaluation of laser radiation upon arteriosclerotic lesions.
Responses of atherosclerotic aorta to argon laser
Authors: Dries David J. , Lawrence Peter F. , Syverud John , Moatamed Farhad , Dixon John
Published: March 2007

Lasers have been advocated to resect atherosclerotic plaques in the cardiovascular system, yet little information is available regarding the effects of laser on the range of occlusive lesions seen in the peripheral arterial tree. This study was conducted to assess the risk of perforation in human cadaveric aorta involved with variable degrees of atherosclerosis. Ten fresh segments of atherosclerotic human aorta were graded for extent of atherosclerosis, then subjected to argon laser energy within 48 hours. Using air as the conduction medium and with the fiber tip 2 or 5 mm from the vessel wall, the argon laser was applied to matched calcified and non‐calcified arteries at 3.0‐7.0 W and 10.0–13.5 W with energy density identical for matched pairs. Results were compared among segments which were normal in appearance or had only fatty streaks grossly with those with gross regional wall calcification. The mean penetration time (T) for calcified and non‐calcified lesions at low and high power outputs was compared.

magnified image

Mean time to perforation and range of time necessary to produce perforation were greater in calcified than non‐calcified segments at all power levels employed. These data suggest that atherosclerotic lesions vary in their response to argon laser. The presence of calcium may preclude resection of some plaques and protect against wall perforation.
Histological studies of myocardium zones irradiated with Nd–YAG laser
Authors: Obelienius V. , Knepa A. , Lubite Y. , Ambartzumian R. , Isakov V. , Koshelev E. , Markin E.
Published: March 2007

Histological investigation of the dog's myocardium performed 7 and 25 days after irradiation with different doses of Nd‐YAG laser show that the damage zone has the shape of a hollow sphere with minor changes in cardiomyocytes in the central part of the sphere. The small blood vessels in the irradiated zone remained undamaged as well. A tentative explanation of the physical process that leads to this type of coagulation zone is given.
Photodynamic therapy of gynecologic neoplasms after presensitization with hematoporphyrin derivative
Authors: McCaughan James S. , Schellhas Helmut F. , Lomano Jack , Bethel Bradley H.
Published: March 2007

Five patients with various gynecologic neoplasms were treated with photodynamic therapy using 630‐nm light delivered from an argon dye laser system following the intravenous injection of hematoporphyrin derivative (HpD). A patient with multifocal squamous cell cancer of the vagina had no evidence of disease 15 months after her first photodynamic therapy treatment. Autopsy nine months after the first treatment of another patient with multifocal invasive cancer of the vagina and parametrium showed no evidence of tumor on the surface of the vagina. Eight months after treatment of an 8 × 12 cm area of Bowen's disease of the vulva and thigh, there was no evidence of disease. Vaginal bleeding from breast cancer metastatic to the endometrium was controlled by one treatment until the patient expired five months later from her disease. Adenocarcinoma metastatic to the vaginal cuff showed partial response when vaginectomy was performed five weeks after photodynamic therapy.