bluuebunny/crossref_metadata_2025 huggingface dataset:
Transventricular revascularization by Laser
Authors: Mirhoseini M. , Muckerheide M. , Cayton M. M.
Published: March 2007

Transventricular acupuncture or revascularization by the method of producing channels between the ventricular cavity and the ischemic myocardium has challenged several investigators. The concept of producing these channels using high‐energy CO2 laser was based on the finding that the laser beam could produce small channels devoid of debris, and fibrosis would not occur.

Four groups of mongrel dogs with six animals in each group were studied. In three groups the left anterior descending (LAD) branch of the coronary arteries was ligated above the first diagonal, and channels were made in the myocardium according to the protocol for each group. The fourth group was the control, the LAD was ligated but the myocardium was not exposed to laser treatment. In the control group all animals died within 20 minutes of LAD ligation. Animals in the other groups survived ligation with laser, and were subsequently sacrificed at varying intervals. At autopsy the epicardial component of the channels was visible. Penetration through the myocardium could be demonstrated. Microscopically the channels were patent and endothelialized. Further investigations are in process, but we believe laser channels protect and nourish the ischemic myocardium.
The outpatient‐procedure effectiveness of laser treatments in oncology
Authors: Bandieramonte G. , Di Pietro S. , Andreola S. , Azzarelli A. , Chiesa F. , Luciani L. , Marchesini R. , Emanuelli H.
Published: March 2007

The outpatient procedure of CO2 laser surgery has been recently integrated into the routine activity of the National Cancer Institute, Milan. Specific operative protocols that are codified for laser outpatient selection after adequate staging by pathology are presented. Specific indications for gynecologic disease (preneoplastic disorders, CIN, VAIN, and VIN), and general‐surgery neoplastic disorders (soft tissue sarcomas, lip and oral cavity lesions, breast lesions) are described. Details of the safety procedures, rules of application, laser instrumentation accessories and wattages, both with vaporization and excisional technique, are reported. An overall rate of 30% out of the 4,000 cases treated yearly are selected for laser treatment procedures on the basis of the evaluation of real advantages. The general advantages of laser surgical applications such as reduction of bleeding and postoperative pain, early and late complications; no‐touch method; and patient acceptability—have been emphasized in the routine outpatient procedures. Reduction of the total costs and of the waiting list for hospitalization by the new procedures are finally considered.
Endoscopic laser arytenoidectomy
Authors: Ossoff Robert H. , Karlan Mark S. , Sisson George A.
Published: March 2007

Most patients with bilateral vocal cord paralysis have a fairly satisfactory voice, but their airway is usually inadequate for day‐to‐day exertion. In some patients, the airway may be inadequate for even quiet respiration and an indwelling tracheotomy is required. Solution to this problem has involved the following techniques: tracheotomy, lateralization of the vocal cord by either endoscopic or external routes, or vocal cord reinnervation by the nerve‐muscle transposition technique.

Endoscopic laser arytenoidectomy has been mentioned in the literature. However, the actual technique as well as the attendant morbidity associated with this procedure has not been highlighted.

Four patients with bilateral vocal cord paralysis of the larynx have been treated by endoscopic laser arytenoidectomy at Northwestern University Medical School. The technique, problems, and results are discussed.
A flexible sealed tube transverse radio frequency excited carbon dioxide laser for dermatologic surgery
Authors: Goldman Leon , Perry Edward , Stefanovsky David
Published: March 2007

A new CO2 laser system, of special characteristics, has been found to be effective for CO2 laser dermatological surgery. The unit is compact, freely movable, and suitable for office practice. A highly flexible operating probe makes for precision surgery. The initial investigative clinical series included resistant warts in many areas including extensive plantar warts, oral lesions, and condylomata. There were also excisions of broad base granuloma pyogenicum, large seborrheic warty lesions, thermal photocoagulation of rhinophyma, and laser dermabrasion of tattoos. Flaps were done in animals.
Carbon Dioxide Laser Treatment of Vaginal Adenosis in DES‐Exposed Offspring: A Prospective Study
Authors: Bellina Joseph H. , Fischer Ross Lynne , Hemmings Robert , Voros Janos I. , Moorehead Myron
Published: March 2007

Seventy‐nine patients with history and physical findings characteristic of antenatal DES exposure were randomly divided into two groups. Fourty‐four DES‐exposed offspring had their vaginal adenosis treated with the carbon dioxide laser (group I), and the remaining 35 DES‐exposed offspring (group II) did not receive any specific treatment for this condition. Additionally, the 79 DES‐exposed offspring were compared to an age‐matched control population (group III). Treatment of vaginal adenosis with the carbon dioxide laser did not significantly reduce the incidence of development of new dysplasia in the DES‐exposed offspring. This study also showed no statistical difference (p ≤ 0.05) in the incidence of dysplasia in DES‐exposed offspring as compared to a control population.
Microbial Contamination by a Medical Carbon Dioxide Laser
Authors: Dmd Dr Ilana Eli , Judes Herbert , Rosenberg Mel
Published: March 2007

One of the advantages in using the carbon dioxide laser in medicine is the sterilization of the wound at the site of surgical intervention. In microbial studies, using the Sharplan Model 743 Medical Laser, we found substantial contamination of the area directly below the probe by viable bacteria and fungi. The levels of contamination varied from experiment to experiment, but were always substantial. The contamination is likely due to the stream of nitrogen gas emitted during and following laser irradiation in order to cool the lens. Following the implementation of several simple prophylactic procedures, including insertion of a filter on the end of the tube emitting the nitrogen gas, contamination by the gas stream was reduced to insignificant levels.
Destructive, Nonclassical “Beating” of Acoustic Waves and Electric Field Generation in Lased Heart Muscle
Authors: Ward H.
Published: March 2007

Increased use of the laser in heart research warranted examination of the physical effects of the laser on the heart muscle. Laser action on the heart muscle was found to induce nonclassical (nonlinear) properties in the muscle such as low‐frequency harmonics of acoustic transients. This “beating” effect resulted in a destructive thermal‐wave propagation within the tissue. The nonlinear effects found in lased heart muscle had not been previously observed and occurred at laser intensities two or three orders of magnitude lower than those which occur in nonbiological media. One possible explanation of this nonlinear behavior at lower intensities was the finding that the laser induced an electric field in heart muscle which interfered with cell‐membrane resting potential, and conduction. Temperatures above 300°C were recorded. These are very high, considering that cells are 80–90% water, and that the boiling point of water is 100°C. The laser crater profile exhibited a two‐stage effect which was atypical according to conventional thermal theory. Electron micrographs demonstrated an unexpected capillary growth which had occurred postmortem in the lased heart muscle.
Hematoporphyrin‐Derivative and Photoradiation Therapy of Malignant Tumors
Authors: McCaughan James S. , Guy Jerry T. , Hawley Philip , Hicks William , Inglis William , Laufman Leslie , May Eugene , Nims Thomas A. , Sherman Rand
Published: March 2007

Kodak projectors with #2418 red Corning filters were used as a light source to treat cutaneous and subcutaneous malignancies in five patients who previously had been given hematoporphyrin derivative (HpD). An argon dye laser system was used to treat malignancies in patients who also were given the HpD. These tumors included 11 melanomas of the eye, three carcinomas of the esophagus, one melanoma of the esophagus, four carcinomas of the lung, three basal cell skin cancers, and one retropharyngeal metastatic oral cancer. Clinical results and technical problems of this therapy are discussed.
Microsurgery of the Fallopian Tube With the Carbon Dioxide Laser: Analysis of 230 Cases With a Two‐Year Follow‐Up
Authors: Bellina Joseph H.
Published: March 2007

Between September 1979 and December 1982, 230 cases of tubal reconstructive surgery were followed for 2 years. An analysis of these cases showed 75% to have had more than one procedure performed. There were 91 pregnancies in this group. In the bipolar disease population, 36% achieved an intrauterine pregnancy. Tubal reversal procedure resulted in comparable rates when compared to conventional surgery (71%). The ectopic pregnancy rate was 4.4%, and spontaneous abortion rate was 6.6%.

The carbon dioxide laser appears to have a place in the armamentarium of the microsurgeon.
Laser‐Assisted Vas Anastomosis: A Preliminary Report
Authors: Lynne Charles M. , Carter Melvin , Morris James , Dew Douglas , Thomsen Sharon , Thomsen Cathy
Published: March 2007

A new technique is described for performing vas anastomoses in experimental animal (rats). A low‐power CO2 laser appears to be effective in welding together the cut ends of the divided vas deferens.
Clinical Experience With CO2 Laser Vaporization of Neoplasm
Authors: Nims Thomas A. , McCaughan James S.
Published: March 2007

The use of the CO2 laser in the treatment of two types of cancer, advanced ovarian carcinoma and tumors of the liver, has proven to be a useful form of adjunctive therapy. It has proven effective in vaporizing ovarian tumors ranging in size from 5 to 20 mm and liver tumors ranging in size from 1 to 4 cm. This modality is preferable to traditional excision‐and‐repair techniques, which are far more traumatic and may result in considerable loss of blood.
Argon and Carbon Dioxide Laser Treatment of Hypertrophic and Keloid Scars
Authors: Henderson Darrell L. , Cromwell Terry A. , Mes Louis G.
Published: March 2007

Laser physiology has shown that while wound healing is generally excellent after laser impaction, it nevertheless is delayed. It is thought that this factor may be important in the treatment of hypertrophic and keloid scars. These scars have been treated in a variety of ways with the laser, and the results, which have been good, are reported. A possible explanation of the complex mode of action has been given. It is thought that more work should be undertaken in this field.
CO2 laser conization versus conventional conization: A clinico‐pathologic appraisal
Authors: Meandzija Miodrag (Mile) P. , Locher Gotfried , Jackson Jeff D.
Published: March 2007

Two groups of patients recently underwent either laser or conventional conization at the University Women's Hospital in Bern, Switzerland. Of the total 49 patients treated, 25 underwent laser conization and 24 underwent conventional conization. All patients admitted to the study had cytologic, colposcopic, and/or histologic evidence for cervical intraepithelial neoplasia or chronic cervicitis resistant to conservative therapy. In the conventionally treated group. conization was performed with surgical scalpel, and hemostasis was achieved by Sturmdorff, Bonney, or Kraus sutures. In the laser‐treated group, conization was performed by using the combination method of Dorsey and Grundsel.

Blood loss was minimal in the laser‐coned patients, compared to 119 ml blood loss in the conventionally coned patients.

Hospitalization for the laser‐treated group was 5·2 days in contrast to 7·0 days for the conventionally treated group. Postoperative bleeding and discharge were also considerably smaller or did not occur in the laser‐treated group as compared to the conventionally treated group. With postoperative and long‐term follow‐up now under way, initial results indicate that laser conization, in comparison to conventional conization, also provides greater visibility of the squamocolumnar junction and a reduced incidence of cervical strictures.

The results of this study suggest that the CO2 laser beam, properly and cautiously applied, is an efficacious surgical modality for the treatment of cervical preneoplastic disease.
Patients' evaluation of argon laser therapy of Port Wine Stain, decorative tattoo, and essential telangiectasia
Authors: Dixon John A. , Rotering Robert H. , Huether Sue E.
Published: March 2007

One hundred fourteen patients wer studied to assess their perception of the results of argon laser therapy for port wine stains (PWS), tattoos, or essential telangiectasia of legs. At least 1 yr following treatment patients were surveyed using a 30item mail questionnaire. A 91% response rate was achieved.
Influence of Nd:YAG laser power density and coaxial CO2 on the gastric wall
Authors: Joffe S. N. , MacLeod I. A. , Rao S. S.
Published: March 2007

A detailed understanding is required of the effect of Nd: YAG power density and coaxial CO2 on tissue necrosis in both the acute and healing situation. Lesions were produced by varying peak powers at eight increments of 10 W from 40–110 W/sec for a time duration of 1 sec with and without coaxial CO2 on the rabbit (n=16) stomach. Surface areas and careful histological examinations were performed at 2 hr and 4 days. In further experiments, a total incident energy of 60 or 120 J with varying peak powers from 30‐120 W/sec were applied at a 1‐cm distance. The lesion surface area at 1 cm was 21.7 mm2 compared to 12 mm2when the fiber tip was held 2 cm away (p < 0.05). Coaxial CO2 at 1 cm reduced the surface area to 10 mm2 (p < 0.001). There was a positive correlation between surface areas and the incidental power (r = 0.86, p < 0.01). There was no significant difference in the mean surface area of lesions at 2 hr compared to those at 4 days, nor was there a correlation between the increasing peak powers with the constant incident energy. Histological features were those of coagulative necrosis (81 %)‐with minimal ulceration (1.6%) at 2 hr with ulceration increasing to 22% at 4 days. These results have helped in planning a safe and effective Nd:YAG photocoagulation study in patients in order to obtain maximum hemostasis with minimal tissue injury.
Laser surgery for soft tissue purulent diseases
Authors: Chegin Vyacheslav Mikhailovich , Skobelkin Oleg Ksenophontovich , Brekhov Eugeny Ivanovich
Published: March 2007

The original techniques of soft‐tissue purulent lesion treatment by means of a continuous‐wave CO2 laser are elaborated. The following laser treatment advantages—minimal tissue damage, prophylaxis of local dissemination of infection, heamostatic and sterilizing effects—have been proved experimentally. Laser utilization in clinical trial (360 cases) made it possible to obtain significantly improved outcomes and marked shortening of treatment.
Innovations. An advanced clinical trial with laser acupuncture anesthesia for minor operations in the oro‐maxillofacial region
Authors: Dds Zhou Yo‐Cheng
Published: March 2007

For the purpose of improving acupuncture and acupressure anesthesia, laser acupuncture as a new type of controlled anesthetic method has been used since 1979.

A beam from a 2.8–6 mW helium‐neon laser apparatus (Model CW‐12, Chengdu Thermometer Factory) was delivered and focused to a red spot on the selected skin point of the patient. The laser was used instead of the routine acupuncture and acupressure anesthesia.

This paper reports the clinical laser trial of 610 cases (562 cases of difficult exodontia and 48 cases of various minor operations in the oro‐maxillofacial region). The effect of analgesia was satisfactory. No sedatives or analgesics were administered before or during operations.

The helium‐neon laser apparatus, selection of laser irradiating acupuncture points, distance, and duration of irradiation and clinical observations are described.
Fundic vagotomy by waveguide CO2 laser: Experimental study of a new technique in dogs
Authors: Bourez Jean , Triboulet Jean‐Pierre , Wahlen Christian , Balester Louis , Lemaire Jean , Herlemont Francois , Scopeliti Joseph , Brunetaud Jean‐Marc
Published: March 2007

Anterior lesser curve seromyotomy with posterior truncal vagotomy is an alternative operation to the highly selective vagotomy. After preoperative gastric function testing, four dogs underwent an anterior lesser curve seromyotomy with posterior truncal vagotomy. However, a new prototype hand‐held laser was used to perform the seromyotomy. This laser delivers 20 W and is small, light, and highly maneuverable. Results of the operation indicate that this laser was easy to use and yielded a very effective seromyotomy without complications. Peroperatively, the laser performed simultaneous section and hemostasis. Postoperatively, no significant acid production could be stimulated with either histamine, pentagastrin, or insulin. This operation yields good control of acid production and is faster and easier than the highly selective vagotomy. The hand‐held waveguide CO2laser may further facilitate the ease of this procedure.
The biomedical effects of laser application
Authors: Mester Endre , Mester Andrew F. , Mester Adam
Published: March 2007

This paper briefly reviews the authors' experimental and clinical use of lasers over a 20‐year period, during which laser effects on 15 biological systems were studied. Low‐energy laser radiation was found to have a stimulating effect on cells, and high‐energy radiation had an inhibiting effect. The application of lasers to stimulate wound healing in cases of nonhealing ulcers is recommended.
Argon laser coagulation of blood for the anastomosis of small vessels
Authors: Krueger R. R. , Almquist E. E.
Published: March 2007

A new technique is introduced in which an argon laser coagulates blood to form an adherent sleeve for the anastomosis of small vessels. The argon laser solidifies the blood into a dark tensile substance which supports the site of repair until vascular continuity is achieved. Laser pulses of 0.75 W and 0.5 seconds exposure are used, and damage to the underlying vessel wall is minimal. A histological analysis is performed and the results are examined qualitatively. The technique shows advantages of speed, reduced vascular trauma, and external protection at the site of vascular repair.
The monochromatic green argon laser in the management of macular disorders
Authors: Gazocchi M. , Fattori C.M. , Gratton I. , Simonini F. , Citroni M.
Published: March 2007

The authors have been using an argon laser photocoagulator equipped with a green filter for about 2% years. Compared to the usual blue‐green argon laser, the advantage of such an instrument is that green radiation is not absorbed to any significant degree by macular pigment. This ensures a selective action on hemo‐globin and pigment epithelium. The green wavelength appears to be extremely useful in the management of macular disorders.

The authors report the criteria they follow and the technique they use in the treatment of subretinal neovascular membranes and of macular edema arising from different retinal vascular disorders.
“Hot tip”: Another method of laser vascular recanalization
Authors: Abela George S. , Fenech Albert , Crea Filippo , Conti C. Richard
Published: March 2007

This study is a preliminary report evaluating the use of laser radiation to heat a metal‐capped fiber for arterial recanalization. The method was compared to the currently used bare‐ended fiber for recanalization of occluded vessels. The model used was a human coronary artery xenograft transplanted in the femoral artery of the dog. At 4 weeks following the transplantation, laser recanalization was attempted using the heated metal probe (“hot tip”) in five arteries and the bare fiber in another five arteries. Results: 1) Angiography demonstrated recanalization in all five arteries treated with the “hot tip” and three of the five arteries treated with the bare fiber. 2) Only one perforation occurred with the “hot tip,” whereas three perforations occurred with the bare fiber. 3) The larger metal cap was capable of creating a wider channel in the occluded arterial segment. Although the trend favored the heated metal cap in terms of recanalization and less perforation than the bare fiber, the total number of experiments were not adequate to demonstrate statistical significance. Microscopic examination of the vessels recanalized by either technique was similar. Characteristic charring at the recanalization site was seen regardless of the technique used. These observations suggest that the effect of direct laser radiation on plaques is predominantly a thermal effect. Although these results would suggest utilization of a metal‐capped fiber for vascular recanalization, more studies need to be done to confirm these preliminary findings.
Retinal effects of the frequency‐doubled (532 nm) YAG laser: Histopathological comparison with argon laser
Authors: Mosier Marjorie A. , Champion Jean , Liaw Lih‐Huei , Berns Michael W.
Published: March 2007

Retinal lesions produced in Dutch Cross rabbits with a frequency‐doubled (532 nm) YAG laser in single pulse mode (30–100 μJ) and in train of uniform pulses (2.6 and 7.5 mJ) underwent histopathological examination by light and electron microscopy. The results were compared to argon laser lesions (11 and 15 mJ) in the same animals. Low‐energy single‐pulse YAG lesions produced separation of the neural retina from the retinal pigmented epithelium (RPE), while higher energies caused severe disruption of retinal structures with moderate damage to the RPE. A striking and consistent finding of all the single‐pulse lesions was the presence of red blood cells between the RPE and neural layers. The findings appear to support a process of mechanical disruption. In contrast, the lesions produced by a uniform train of pulses showed well‐defined damage to RPE and photoreceptors with no red blood cells between these two layers, no choroidal damage, and relatively little disruption of the inner retina. The typical argon lesion evidenced cellular damage from the RPE through all retinal layers. Leukocytes in the choroid contained “holes” or vacuoles not seen in YAG lesions. Both the uniformly pulsed YAG laser burst and argon laser produced effects consistent with a thermal process. Some differences between argon and YAG burst were observed. The results suggest that there may be a clinical potential for the 532‐nm burst YAG in treating retinopathies.
Preliminary study of the Nd:YAG laser in canine partial nephrectomy
Authors: Benderev Theodore V. , Schaeffer Anthony J.
Published: March 2007

Partial nephrectomy is effective in the treatment of segmental renal disease but hemostasis remains a challenge. In this preliminary investigation the Nd:YAG laser was used alone or as an adjunct to the scalpel in partial nephrectomies to determine if hemostasis could be improved. A technique of 100‐W laser transection with occlusion of the renal artery was effective for partial nephrectomy and achieved complete hemostasis. Conditions of patent renal artery flow or renal cooling were associated with a reduction in necrosis depth with 100‐W laser partial nephrectomies. All techniques were compatible with survival over the 5‐day study period.
Computer analysis of laser dosimetry data: A method of accurate energy density delivery
Authors: Karbaj Antoine N. , Ahigian Gerald T. , Stewart Alan , Edralin Melvin , Abergel R. Patrick , Dwyer Richard M. , Lesavoy Malcolm A. , Uitto Jouni
Published: March 2007

In the past, utilization of the laser in medicine has been limited by the lack of accurate quantification of the energies delivered to the tissue. Data obtained in the course of this investigation have demonstrated the relationships which exist between the energy delivered to the tissue and the optical system composed of the fiber and focusing lens. A continuous‐wave multimode Nd:YAG laser (1,064 nm) was used in these experiments. Utilizing the beam scan technique previously described, we recorded over 100 beam profiles at various distances from the handpiece (fiber optic and lens). Computer analysis of our data established the mathematical correlation between the surface area of the irradiated spot and the distance of the handpiece to the target, thus allowing us to predict the surface area of the irradiated spot to any desired distance.

By duplicating our methods with his particular optical system, the clinician or any laser user has the capacity to determine the energy delivered to the tissue (J/ cm2) by knowing the power of the laser (watts), the time of exposure (seconds), and the distance of the handpiece to the treatment site (centimeters).
Transvenous ablation of the atrioventricular conduction system by laser irradiation under endoscopic control
Authors: Obelienius V. , Knepa A. , Ambartzumian R. , Markin E. , Koshelev E.
Published: March 2007

We report ten successful experiments of transvenous destruction of the His bundle by laser radiation. An endoscope coupled with a special laser catheter was introduced through the jugular vein into the right atrium of dogs. The tip of the laser catheter was positioned in front of A‐V conduction system under visual control using anatomic landmarks. Injection of saline solution coaxial with the laser power‐transmitting fiber was performed before and during laser coagulation. Twenty watts constant wave Nd‐YAG laser operating at 1.06 μm was enough to produce complete A‐V block in approximately 15 sec. The safety of the proposed technique is especially discussed.
Status quo and new horizons of laser therapy in neurosurgery
Authors: Ascher Peter Wolf
Published: March 2007

Eight years of experience with the CO2 laser and 4 years experience with the neodymium laser in 737 neurosurgical cases are presented with absolute and relative indications and observations. Future developments are discussed.
Current uses of the laser for fertility‐promoting procedures
Authors: McLaughlin David S.
Published: March 2007

The addition of lasers to the gynecologist's surgical armament has been heralded by some and scoffed at by many. Only through scientific assessment of published data using this new technique is one able to obtain an intelligent perspective of the clinical applicability for the laser in fertility‐promoting procedures. A review of the literature, with stated pregnancy rates, describing the delivery of the carbon dioxide, argon, and Nd:YAG lasers via laparotomy or laparoscopy is presented. It is hoped that as this new surgical modality evolves, additional studies will further define its role in preserving or enhancing reproductive potential.
Carbon dioxide laser treatment of porokeratosis of mibelli
Authors: Groot Donald W. , Johnston Patricia A.
Published: March 2007

Porokeratosis of Mibelli, a disorder of keratinization, has in the past been difficult to treat, especially in its more extensive form. The carbon dioxide laser was used in the treatment of a patient with this disorder. The response was very favorable. Microscopic pathological investigation after treatment revealed no residual evidence of porokeratosis in the areas treated with the carbon dioxide laser. Thus, obliteration of this disease process using the carbon dioxide laser shows potential for future use.
Treatment of cutaneous and deep vascular lesions with the Nd: YAG laser
Authors: Rosenfeld Harold , Sherman Randolph
Published: March 2007

This study intends to document and evaluate the first compiled experience in the treatment of both cutaneous and deep vascular lesions using the Nd:YAG laser.

Thirty‐eight patients were treated over a 5‐year period from 1979 to 1984 using the Nd:YAG laser with FDA approval. Lesions included capillary, cavernous, combined capillary‐cavernous hemangiomas, portwine stains, arteriovenous malformations, lymphangiomas, multiple telangectasias, and one case of Klippel‐Trenaunay‐Webber syndrome. The number of treatments per patient ranged from one to four. Partial or complete resolution of these various lesions, as evidenced by a decrease in size, and/or normalization of pathologic cutaneous changes was noted in a majority of patients.

While both the argon and CO2 lasers have been well studied in the treatment of cutaneous vascular lesions, this is the first compiled series reporting results using the Nd:YAG for such problems. The Nd:YAG laser represents an alternative modality in the treatment of cutaneous hemangiomas and introduces an efficacious method in the treatment of cavernous vascular lesions.
Application of photodynamic therapy in plastic surgery
Authors: Gregory Richard O. , Goldman Leon
Published: March 2007

Photodynamic therapy is a technique for administering a sensitizer, hematoporphyrin derivative, which is selectively retained in malignant tissue. This is then activated by light, usually of 630 nm resulting in selective deterioration of the malignant tissue. This technique has been used for detecting and treating a variety of cancers in experimental animals and human beings. In plastic surgery, it has been applied to both basal and squamous cell carcinomas as well as to other skin lesions. Metastatic deposits will also respond to this treatment. Advantages include ease of treatment, sometimes requiring little or no anesthesia, low incidence of reactions, ability to repeat the treatment any number of times, and sparing of normal tissue. Photodynamic therapy has been used as a salvage operation, to clear tissue of suspected or probable remaining malignant disease, and to alleviate the need for a radical operation, allowing a more conservative one. Photodynamic therapy continues to be an investigational tool, and it should be used only as an adjunct to commonly accepted techniques, and then only when needed. Common disadvantages include a severe photosensitivity of the patient for several weeks following administration of the drug as well as inability to treat adequately bulky tumors. New techniques of administration and methods of activation will make this an increasingly common and useful tool in the practice of plastic surgery.
Treatment of keloids and hypertrofic scars with an argon laser
Authors: Hulsbergen Henning J. P. , Roskam Y. , Van Gemert M.J.C.
Published: March 2007

A report is given on the treatment of keloids and hypertrofic scars using an argon laser. Of the 45 patients who participated, only three patients had a diminishing of over 50%, and 40 patients were classified as obtaining slight improvement, which means a diminishing of between 20 and 50% of the original keloid. Twenty‐seven patients showed no change after treatment with the argon laser and one patient had a poorer result, due to a complication after the last treatment. Directly after treatment, most keloids showed an obvious shrinkage. After several days, however, the keloids became the same size as before treatment. Decrease of tension of the skin after treatment seems to influence the result favorably. We find the best response to treatment with an argon laser in long narrow keloids (hypertrofic scars). In general, the results are disappointing, especially because until now the literature claims good results on this subject.
Is there an optimal laser treatment for port wine stains?
Authors: Van Gemert Martin J. C. , Welch A.J. , Amin Alpesh P.
Published: March 2007

Optimization of laser treatment of port wine stains (PWS) is discussed from the standpoint of heat production. Laser wavelength, irradiation time, heat conduction, and external epidermal cooling are the variables considered in conjunction with absorbing and scattering behavior of a PWS‐model consisting of epidermis, dermis, and ectatic blood vessel. Ideal treatment is defined as minimal heating of the epidermis and upper dermis, but with irreversible damage to the capillary wall. The analysis shows that irradiation times of 1–10 ms in conjunction with external epidermal cooling may give optimal results. The wavelength of choice is 577 nm, followed by 540, 415, 560, and 500 nm (argon laser). The ruby and Nd‐YAG lasers are predicted to damage the epidermis and dermis at all times when the capillary is coagulated. Concurrent cooling to prevent epidermal‐dermal damage is also recommended here. The CO2 laser is predicted to be the worst laser and, according to our analysis, should not be used to treat PWS. Both upper dermal and capillary destruction can only result from heat conduction from the damaged epidermis and external cooling cannot be applied here.
Laser revascularization, 1985: State of the art
Authors: Choy Daniel S. J.
Published: March 2007

Progress in the young field of laser recanalization of occluded arteries and applications in cardiovascular disease to which many investigators have contributed is briefly summarized. Specific problems remaining to be solved are set forth. In conclusion, the author makes a cautious prediction of success for the percutaneous laser catheter within the next 5 years.
Reduction of local tumor recurrence by excision with the CO2 laser
Authors: Lanzafame Raymond J. , Rogers David W. , Nairn John O. , Defranco Cecilia A. , Ochej Helen , Raymond Hinshaw J.
Published: March 2007

This study was undertaken to determine the effect of CO2 laser surgery on the incidence of local recurrence following tumor resection. Thirty female Fisher 344 rats were implanted with R3230AC mammary carcinoma. All tumors were completely excised 18–21 days post‐implantation.

In 15 animals, the resection was done with a scalpel. Fifteen animals underwent laser excision with the Sharplan 733 CO2 laser (TEMoo, 125mm handpiece, 25W continuous wave).

Primary tumor size was 17.6 ± 1.4mm in the scalpel group and 21.2 ± 6.3mm in the laser group. Tumor recurred in 14/15 (93.4%) of the scalpel group and 5/ 15 (33.3%) of the laser group (p<0.001). The site of recurrence was incisional in 13/15 (86.7%) of the scalpel group and 3/15 (20%) of the laser group (p<0.001). Axillary metastases occurred in 2/15 (13.3%) in each group. The disease‐free interval was 26 days in the laser group and 12 days in the scalpel group. The CO2 laser is an effective surgical adjunct to reduce local tumor seeding and recurrence.
Pulsed laser damage thresholds and laser treatment energy parameters, in vivo, of human aphakic intraocular membranes
Authors: Davi S. K.
Published: March 2007

Energy and power density damage thresholds were determined for the perforation of human aphakic pupillary membranes and intraocular lens implants, in vivo, at the focal point of Neodymium‐YAG ophthalmic laser systems, at 1,064 nm, which produced (1) Q‐switched nanosecond pulses (TEMoo, pulse duration; 20 ns) and (2) mode‐locked pulse trains (TEMoo, 9–11 pulses, pulse duration; 30 ps, entire pulse train delivered in 50–70 ns). Pulse energies bracketing the damage thresholds and focal diameter were tabulated. The energy density and power density thresholds for perforation of the pupillary membranes (hereafter referred to as perforation threshold) (1) were slightly lower and power density damage thresholds higher for shorter duration pulses, eg—66 J/cm2 (2,200 GW/cm2) with the picosecond pulse trains vs 80 J/cm2 (2.7 GW/cm2) with the nanosecond pulses and (2) were similar in pseudophakics and aphakics; 78 J/cm2 for pseudophakics vs 83 J/cm2 aphakics, both treated with single nanosecond Nd‐YAG pulses, and 68 J/cm2 for pseudophakic vs 66 J/cm2 for aphakic patients treated with picosecond Nd‐YAG laser pulse trains. The number of laser pulses and pulse energies required for successful discission of the pupillary membranes depended not only on the pulse parameters but also on the characteristics of the membrane, such as thickness, nonuniformity, capsular haze, or capsular haze combined with fibrosis.
Neodymium (Nd): YAG laser surgery in the equine larynx: A pilot study
Authors: Tate Lloyd P. , Newman H.C. , Cullen J.M. , Sweeney C.
Published: March 2007

Laryngeal surgery in the equine is customarily and routinely performed by means of a ventral laryngotomy incision. Such procedures are usually performed under deep general anesthesia with the horse in dorsal recumbency. The objective of this work was to determine the efficacy of an endoscopic approach coupled to a Nd:YAG laser fiber in performing arytenoidectomy. Arytenoidectomy is commonly indicated in the treatment of arytenoid chondritis and in the failure of prosthetic implantation for left laryngeal hemiplegia. This preliminary study was undertaken to determine the feasibility of the endoscopic laser approach to ablate the most difficult of the structures of the larynx, considering tissue structure and density. This procedure was accomplished by using heavy sedation and local anesthesia and was performed in the standing position. This approach appears to be feasible and makes other adjacent structures accessible via the endoscope coupled to a surgical laser. Indications for future pilot applications of laser surgery in the equine larynx are entrapment of the epiglottis, dorsal soft palate displacement, and the ablation of laryngeal cysts and polyps. This pilot study appears to offer a new modality for discrete surgical ablation of this structure, with minimal postoperative complications and a reduced or equivalent convalescent period in this valuable species of animal.
Practical models for light distribution in laser‐irradiated tissue
Authors: Welch A. J. , Yoon G. , Van Gemert M. J. C.
Published: March 2007

The distribution of light in laser‐irradiated biological medium is computed using four different procedures. Values computed with Beer's law of attenuation, Kubelka‐Munk theory, the diffusion approximation, and a seven‐flux model are compared. the proper conditions for using each model are discussed.
Comparative investigations of the effects of the neodymium: YAG laser at 1.06 microns and 1.32 microns on tissue
Authors: Frank F. , Hessel S. , Beck O. J. , Keiditsch E.
Published: March 2007

The beneficial deep homogeneous coagulation of neodymium (Nd):YAG laser radiation at 1.06 m̈m owing to low absorption and high scattering in tissue has been documented widely. For another Nd:YAG laser wavelength at 1.32 m̈m the absorption coefficient of water and saline is approximately ten times higher than at 1.06 m̈m. This results in more efficient energy conversion into heat in tissue at 1.32 m̈m. The extinction coefficient in blood at 1.32 m̈m is only one‐third of that at 1.06 m̈m. We would expect this to result in less heat dissipation by blood and deeper penetration in tissue at 1.32 m̈m. Nevertheless, at this wavelength scattering also contributes to an effective, uniform distribution of the laser light in the tissue. Animal experiments have been done to examine the effect of wavelength, irradiation time, and beam geometry on tissue damage and to assess its possible clinical uses. The results imply that the 1.32 m̈m wavelength will produce further indications for the use of the Nd: YAG laser in surgery.
Dot or pointillistic method for improvement in results of hypertrophic scarring in the argon laser treatment of portwine hemangiomas
Authors: Apfelberg David B. , Smith Teruko , Maser Morton R. , Lash Harvey , White David N.
Published: March 2007

In an attempt to limit scarring, 51 patients have been treated over a period of 2 years with the argon laser in a dot or pointillistic fashion. One‐ to 2‐mm dots are blanched at intervals of 1–2 mm with minimal power, and the interspaces are filled in at 12 weeks. Scar‐prone areas of the face such as the upper lip, nasolabial fold, nose, and lower lip have been successfully treated with minimal scarring and good fading. Lesions of the trunk and extremity have also been successfully treated.
Dose measurements in photodynamic therapy of cancer
Authors: Profio PhD A. Edward , Doiron Daniel R.
Published: March 2007

A theory and method for prediction and measurement of the effective absorbed dose in photodynamic therapy of cancer is presented. The method depends on measuring the concentration of the photosensitizer (such as dihematorporphyrin ether), the flux density of the light, and the relative photodynamic effectiveness. Previous, less exact methods relied on specifying the drug dosage and delay after injection and or the irradiance at the surface or power from an interstitial fiber. The new formulation should permit closer control of the effective absorbed dose and better clinical results with photodynamic therapy.
Laser irradiation and balloon dilatation in experimental transluminal angioplasty
Authors: Vassanelli Corrado , Menegatti Giuliana , Silverstein Betty , Zardini Piero , Cubeddu Rinaldo , Russo Vera , Svelto Orazio
Published: March 2007

Percutaneous transluminal balloon angioplasty (PTA) is being currently used in patients with coronary artery disease. Laser irradiation (LI) had been effective in vaporizing atherosclerotic plaques. The purpose of this work was twofold: (1) to compare PTA and LI techniques in the recanalization of experimental obstructive arterial lesions, and (2) to evaluate the possibility of reducing the failures and local complications and increasing the success rate of PTA by the combined use of LI. Atherosclerotic iliac stenoses were induced in 27 rabbits; lesions were evaluated angiographically before and after intervention and were studied histologically and by electron microscopy. Argon‐ion LI delivered through microlens‐tip optic fibers reduced the stenotic area from 64.2 ± 21.8% to 40.3 ± 10.7% (n = 10, P < .01) and PTA from 60.7 ± 15.9% to 30.4 ± 7.7% (n = 9, P < .01). However, percentage reduction was higher in PTA‐treated stenoses (48.4 ± 10.1% vs 34.5 ± 13.5%, P < .0125). In eight more rabbits, low power LI (4.55 ± 1.25 J) was delivered after PTA in dilated segments. Post‐PTA LI further decreased stenoses (from 31.2 ± 7.8% to 29.1 ± 8.1%, P < .0125); laser‐irradiated segments showed diffuse carbonization of the disrupted intimal layer. The normalized transtenotic pressure gradient decreased significantly in all groups: LI reduced the gradient from .40 ± .25 to .17 ± .07 (P = .005); PTA from .37 ± .14 to .11 ± .04 (P = .001); LI after PTA from .40 ± .16 to .12 ± .06 (P = .001). Thus, LI is effective (less than PTA) in relieving experimental atherosclerotic stenoses and seems useful when combined with PTA.
Laser treatment of obstructive endobronchial tumors: Factors which determine response
Authors: Lam Stephen , Muller Nestor L. , Miller Roberta R. , Kostashuk Edmund C. , Laukkanen Ethan , Evans Kenneth , Szasz Ivan J. , Leriche Jean C. , Champion Paul
Published: March 2007

To investigate whether computerized tomography (CT) and radionuclide quantitative ventilation‐perfusion lung scan add any useful information to a carefully performed endoscopic examination in determining the response of patients with obstructive endobronchial tumors to laser treatment, the findings in 40 patients treated with photodynamic therapy (PDT) or the Nd:YAG laser were analysed. Endoscopic laser treatment was found to be most effective when the tumor was polypoid in appearance bronchoscopically, with little or no submucosal invasion or peribronchial extension seen on CT. When bronchoscopy and CT showed increasing submucosal and/or peribronchial disease, the immediate and long‐term response to treatment was poorer. CT provided valuable information regarding the extent of the peribronchial involvement and airway distortion which were often underestimated by bronchoscopy alone. Reduction of regional perfusion out of proportion to ventilation on scintigraphy in the involved lung zone was found to be associated with extensive peribronchial involvement. We conclude that the addition of CT and radionuclide quantitative ventilation‐perfusion lung scan to bronchoscopic examination is useful in predicting the response of patients with obstructive endobronchial tumors to laser treatment. Whether PDT or YAG laser is more effective in relieving endobronchial obstruction by tumor awaits a randomized controlled trial.
Effects of low‐energy He‐Ne laser irradiation on posttraumatic degeneration of adult rabbit optic nerve
Authors: Schwartz Michal , Doron Avi , Erlich Muni , Lavie Vered , Benbasat Sjana , Belkin Michael , Rochkind Simon
Published: March 2007

Axons of the mammalian peripheral and central nervous systems degenerate after nerve injury. We have recently found that He‐Ne laser irradiation may prevent some of the consequences of the injury in peripheral nerves of mammals. In the present study, the efficacy of the laser in treating injured neurons of the mammalian CNS was tested. Optic nerves of adult rabbits were exposed daily for 8‐14 days to He‐Ne laser irradiation (14 min, 15W) through the overlying muscles and skin. As a result of this treatment, the injured nerves maintained their histological integrity, which is invariably lost in injured mammalian CNS neurons.
Nd:YAG laser ablation of early pelvic endometriosis: A report of 61 cases
Authors: Lomano Jack M.
Published: March 2007

Sixty‐one patients with mild or moderate endometriosis were treated with the Nd:YAG laser between May 1983 and March 1986. During the follow‐up period, 31 patients received no supplemental medical treatment. Ten patients were given danazol, five for recurrence of pain and five because of the extent of the disease. Sixteen patients were given oral contraceptives, 12 for birth control and four for pain. Four patients received danazol plus oral contraceptives as concurrent therapy. Overall, symptoms improved following surgery for 45 patients (74%); two patients (3%) reported a worsening of symptoms, while 12 patients (20%) reported no change in their symptoms. The overall improvement rate was 65% for those receiving no hormonal treatment, 70% for those on danazol, 94% for those on oral contraceptives, and 75% for those on both contraceptives and danazol. This latter finding, however, is not significant because of the small patient sampling. Nevertheless, these findings reflect the benefit of laser ablation of early‐stage pelvic endometriosis with or without the concurrent use of conservative medical therapy.
The influence of hands‐on laser training on usage of the CO2 laser
Authors: Lanzafame Raymond J. , Herrera H. Raul , Jobes H. Marie , Naim John O. , Pennino Ralph P. , Porter Noreen , Pizzutiello Robert J. , Rogers David W. , Hinshaw J. Raymond
Published: March 2007

A questionnaire was distributed to all participants in the Rochester General Hospital CO2 laser training workshops for surgeons (1982 to January 1985). The results of this study indicate that, while laser training is necessary prior to being able to use the laser, only a small fraction of trainees actually use the laser in their clinical practice. Surgeons who are using the laser do so in a minority of their cases. New incentives for laser usage must be investigated.
A model for thermal ablation of biological tissue using laser radiation
Authors: Partovi F. , Izatt J. A. , Cothren R. M. , Kittrell C. , Thomas J. E. , Strikwerda S. , Kramer J. R. , Feld M. S.
Published: March 2007

We present a theory of thermal laser ablation based on the heat equation and on an energy balance equation derived from it. Ablation is assumed to be brought about by the heating and evaporation of tissue water. The model is three‐dimensional, and scattering and the water‐steam phase transition are explicitly taken into account. The model predicts threshold parameters and a steady‐state ablation velocity in terms of the optical and thermal properties of the tissue and the laser beam intensity and spot diameter.