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Venous ulcers are chronic wounds affecting up to 1% of adults in developed countries. Considering that noncontact normothermic therapy has been shown to modify the wound healing process, we conducted a prospective comparative clinical trial aimed at evaluating 980 nm diode laser in laser-assisted venous ulcer healing. Thirty-four Caucasian patients with venous leg ulcers were included in the study and separated into two homogenous groups based on age, sex ratio, size, and etiologies of the ulcers. In the laser group, 980 nm InGasAs diode laser (power 15 W, spot size 8 mm, time 3 seconds, fluence 90 J/cm) was applied weekly for 9 weeks to the ulcers in a homogenous standardized manner, resulting in a local temperature of 45-50 °C, which was controlled with a thermal infrared camera. Complete healing, reduction in size, and pain during and between each procedure were evaluated each time. Of the 18 patients in the laser group, three (16.7%) were completely healed during laser treatment. In the control group (16 patients), the healing was complete for four patients (25%). This difference was not significant ( p=0.62). At the ninth follow-up visit, in the control group, the ulcers had decreased on an average to 94.3% of the original area of the ulcers. In the laser group, the decrease was to 74.2% of the original area of the ulcers. Again, this difference was not significant ( p=0.60). The mean VAS score between each treatment was 2.7 (0.5-4.4) in the laser group compared with 3.8 (2.3-5.0) in the control group (0.13< p<0.86). During the treatment, the mean VAS score was 1.8 (0.2-3.8) in the laser group compared with 3.8 (2.1-6.0) in the control group (0.08< p<0.67). 980 nm diode laser-assisted venous ulcer healing was easy to perform and very well tolerated. However, there were no statistically significant differences in reduction of ulcer size between the two groups, suggesting that this particular laser regimen does not promote wound healing. Additional studies involving larger patient populations and an increased frequency of treatment should be performed to confirm our initial conclusions. [ABSTRACT FROM AUTHOR]

Background: Several solutions are now proposed to provide indoor illumination with so-called artificial white light or simulated daylight (SDL- PDT ), resulting in an effective treatment for actinic keratosis (AK). However, the optimal PpIX-weighted light dose is still debated. Integrating the effective irradiance over the irradiation time yields the effective light dose, which is also known as the protoporphyrin IX-weighted light dose and is a key parameter for the efficacy of the treatment. Objectives: The paper aims to report the clinical outcomes of SDL-PDT when using the PpIX-weighted light dose of 4 J/cm 2 , in patients treated for AK lesions of the scalp or the face at our medical dermatology center (ClinicalTrials.gov NCT052036). Methods: A total of 30 patients (16 males, 14 females), with a mean age of 71.0 ± 10.2, with phototype 1 (16 patients) and phototype 2 (14 patients) with grade I-II AK were treated with a drug light interval (DLI) of 10 min and a light exposure of 35 min (Dermaris, Surgiris, Croix, France), corresponding to a PpIX-weighted light dose of 4 J/cm 2 . The primary endpoint was the cure rate of patients at six months post-treatment. Secondary endpoints included scores of pain, erythema, crusts, and discomfort during or/and post the treatment. Results: In total, 762 AK were treated. Six months following treatment, the cure rate of the patients was 77%. The median pain score was less than 1 out of 10 for most of the patients. Erythema was observed in all patients and lasted 3 days (±1.5 day). Crusts were seen in 28 patients. Discomfort was reported as mild or less in more than 97% of patients. Conclusions: The shortening of the PpIX-weighted light dose to 4 J/cm 2 , corresponding to an illumination duration of 35 min with the Dermaris, does not modify the efficacy of the SDL-PDT. This observation is in agreement with recent published data demonstrating that the light dose can be reduced. Furthermore, this clinical study confirmed that SDL-PDT is an effective and nearly painless treatment with minimal side effects for patients with AK lesions of the scalp.

Background: Facial acne scarring is a prevalent disease with both physical and psychosocial sequelae., Aims: This study aims to evaluate an innovative solid state dual wavelength 1,319 and 589 nm laser, which does not require consumable dye, for the treatment of acne scars., Patients/methods: A total of 12 patients (11 female, 1 man - Fitzpatrick skin phototypes II & III) with acne scar for more than one year, were treated with 1319 nm and subsequently by 589 nm, all having four-sessions, one every other week. A full face was covered in approximately 30 minutes. Acne scars were scored by one physician evaluator using the ECCA grading scale before, 2 weeks after each treatment and 1 month and 6 months after the 4th treatment. Safety was measured by recording subject discomfort scores and adverse effects., Results: 12 subjects were enrolled into the study, 10 completed all 4 treatments and 2 were lost to follow up. Fluence used was 28 J/cm² ± 2.4 J/cm² at 1,319 nm and 16 ± 2.9 J/cm² at 589 nm. At baseline, mean ECCA score was 98 ± 23. This score was reduced to 88 ± 30 (p<0.02), after one session, to 68 ± 21 (p<0.01) after 2 sessions, to 58 ± 17 (p<0.01) after 3 sessions to reach 58 ± 15 (p<0.01) 1 month after the 4th and finally 66 ± 11 (p<0.01) at 6 month follow up. This observation corresponds respectively to 14%, 33%, 42%, 40% and 30% reduction of the ECCA score. Only one patient (ECCA score: 120) did not improve after 3 sessions. Slight to moderate erythema was sometimes observed without dryness or bruising. No or minimal burning or stinging was reported. No crust was observed., Conclusion: Improvement in scarring was noted in almost all patients with minimal discomfort and minimal downtime. Combining both minimal side effects with effective acne scar reduction, this laser appears to be highly effective. Long-term evaluation remains necessary to confirm the efficacy of this new laser., (© 2019 Wiley Periodicals, Inc.)

Introduction: The non-invasive vulvar Paget's disease is an intra-epidermal carcinoma with glandular characteristics. It appears like an erythematous plaque. The main symptoms are pruritus and pain. The standard treatment is surgical excision in depth. This treatment is complicated with a severe morbidity and photodynamic therapy can be an alternative choice. However, the pain experienced during the photodynamic treatment of vulvar lesion is intense and leads to a premature interruption of the treatment. The light emitting fabric is a part of a device under clinical evaluation for the treatment of actinic keratosis with photodynamic therapy. We report the observation of a vulvar Paget's disease treated by this device with a satisfactory result and an excellent tolerance., Clinical Observation: The patient has been diagnosed with non-invasive vulvar Paget's disease for 25 years. The disease recurred constantly despite several imiquimod applications, LASER treatments and conventional photodynamic therapy. These procedures were complicated with intense pain. To improve the tolerance, we performed three PDT sessions a month apart using a 16% methyl-aminolevulinate cream (Metvixia® Galderma, Lausanne, Switzerland) with the light emitting fabric at low irradiance (irradiance = 6 mW/cm 2 -fluence = 37 J/cm 2 ) with a satisfactory result and an excellent tolerance., Discussion: There are no controlled trials evaluating the efficacy of photodynamic therapy in the treatment of vulvar Paget's disease. The treatment and follow-up protocols in the literature are heterogeneous. Pain is the most common side effect with greater intensity for perineal locations where photodynamic therapy is impractical outside of anesthesia or hypnosis., Conclusion: We report the case of a multirecidivant non-invasive vulvar Paget's disease treated with a satisfactory result and an excellent tolerance by the new light emitting fabric device. A specific study is required but the light emitting fabric could be indicated for the treatment of Paget disease of perineal location. Lasers Surg. Med. 49:177-180, 2017. © 2017 Wiley Periodicals, Inc., (© 2017 Wiley Periodicals, Inc.)

In the surgical multimodal management of malignant pleural mesothelioma, it seems crucial to proceed with an efficient local adjuvant treatment to kill residual tumor cells. Intrapleural photodynamic therapy has recently emerged as a potential candidate in this goal. In this review, we analyzed and classified 16 articles in which patients with malignant pleural mesothelioma received intrapleural photodynamic therapy after maximal surgical resection. The toxicity, effect on survival, and development of the technique were assessed. After two decades of clinical studies, intrapleural photodynamic therapy after surgical resection became a safe treatment that significantly improved the survival of patients., (Copyright © 2015 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: Since the first studies by Apfelberg in 1994 and the mathematical model of Mordon introduced in 2004, laser-assisted lipolysis (LAL) has been on the rise. In a previous study, we presented our results in patients treated with LAL for Rohrich type I to III aging neck. The average cervicomental angle decreased from 152.6 ± 5.9 to 123.6 ± 8.8 degrees after LAL. This demonstrated a systematic decrease in fat thickness, and improved skin tightening., Objective: This new protocol focuses solely on LAL in the Rohrich type IV aging neck., Methods: Between June 2012 and February 2013, a prospective study was performed on 10 patients treated with LAL for Rohrich type IV aging neck. The laser used in this study was a 1470 nm diode laser (Alma Lasers, Caesarea, Israel). Laser energy was transmitted through a 600 μm optical fiber and delivered in a continuous mode, at 15 W power. Previous mathematical modeling suggested that 0.1 kJ was required in order to destroy 1 ml of fat. Patients were asked to fill out a satisfaction questionnaire. The cervicomental angle was measured 6 months postoperatively, and compared with the preoperative values., Results: No seromas were observed, but prolonged edema was observed in two patients. Pain during anesthesia and discomfort after the procedure were minimal. The average cervicomental angle decreased from 191.5 ± 5.7 to 164.9 ± 14.2 degrees (p < 0.01). This demonstrated a systematic decrease in fat thickness and improved skin tightening. Even though the cervicomental angle was higher than 140° in each case, the investigators, in agreement with the patients, decided to perform a complementary surgery with platysma muscle advancement and plication six months after LAL, in only two of the ten patients. This complementary surgery led to a mean cervicomental angle of 140.2 ± 11.4, and fair satisfaction of both patients and investigators., Conclusion: LAL alone appears insufficient for complete remodeling in Rohrich type IV aging neck. While LAL alone is sufficient for Grade I to III, a complementary surgery must be added for Grade IV.

Onychomycosis is the most common nail disorder. The causative pathogens are not only dermatophytes in the majority of cases (Trichophyton rubrum and T. mentagrophytes), but also yeasts of the genus Candida and molds. A wide variety of topical antifungal agents are proposed for first-line treatment of superficial onychomycosis, when the matrix is not involved. New treatment options using light were recently introduced, such as thermal lasers, non-thermal lasers, and photodynamic therapy. For thermal lasers, a temperature increase in the nail of around 50 °C seems to be a prerequisite for success. For non-thermal lasers, the clinical data are very debatable and their mechanism of action still remains mysterious. For photodynamic therapy, 5-aminolevulinic acid is used. The therapy consists of exciting protoporphyrin IX with red light that penetrates relatively deeply. Further clinical studies of larger series of patients and with longer follow-up are still needed to reach a definitive conclusion on the value of these devices.

Background: Since the first studies by Apfelberg in 1994 and the mathematical model by Mordon in 2004, laser lipolysis (LAL) has been on the rise. Laser lipolysis has the advantages of reduced operator fatigue, excellent patient tolerance, quick recovery time, as well as the additional benefit of dermal tightening. This article reports our experience with laser-assisted lipolysis (LAL) in submental and neck remodelling., Methods: Between June 2010 and January 2013, a prospective study was performed on 30 patients treated for Rohrich type I to III aging neck, with LAL. The laser used in this study was a 980 nm diode laser (Quanta system, spa model D-plus, Solbate Olona (VA), Italy). Laser energy was transmitted through a 600 μm optical fiber and delivered in a continuous mode 15 W power. Previous mathematical modelling suggested that 0.1 kJ was required in order to destroy 1 ml of fat. Patients were asked to fill out a satisfaction questionnaire. The cervicomental angle was measured 6 months post-operatively and compared with the preoperative values., Results: Other than three patients who developed mild hyperpigmentation that disappeared after 4 months, there were no complications in the series. Pain during the anaesthesia and discomfort after the procedure were minimal. The time taken to return to normal activities was 3.2 ± 1 days. All patients would strongly recommend this treatment. Overall satisfaction was high with both patients and investigators and was validated by decrease in cervicomental angle demonstrating a systematic decrease in fat thickness and improved skin tightening., Conclusion: LAL is a safe and reproducible technique for remodeling in Rohrich type I to III aging neck. The procedure allows for a reduction in the amount of adipose deposits while providing concurrent skin contraction.

Hyperhidrosis is a medical problem defined as perspiration in excess of what is normally needed to cool the body. The excessive production of sweat by the sudoriferous glands is independent of the process of thermoregulation. Techniques have recently appeared that make use of energy sources, in particular microwave devices and light (pulsed flashlamp or laser). The aim is to obtain very long-lasting efficacy without notable side effects. Thermal Nd:YAG lasers used with an interstitial fiber, microwave devices, and photodynamic therapy appear to offer new treatment options for axillary hyperhidrosis. However, insertion of a laser fiber into tissue by means of a cannula may lead to complications if the procedure is not well mastered, as has been shown by numerous studies on laser lipolysis. The only microwave device available on the market is certainly interesting. Photodynamic therapy using eosin gel is an attractive technique. The energy source is a pulsed flashlamp, which many physicians have. Eosin gel is relatively easy to produce and these gels are already marketed in several countries. However, further clinical studies of larger series of patients and with longer follow-up are still needed to reach a definitive conclusion as to the value of this approach.

The poor outcome of primary malignant brain tumours is predominantly due to local invasion and local recurrence and their prognosis is highly dependent on the degree of resection. They have no border and, at best, a marginal zone that remains invisible to the surgeon. Photodynamic therapy (PDT) appears to be an interesting modality to fill the need for a targeted treatment that may reduce recurrence and extend survival with minimal side effects. In this review, we summarize the different technologies of brain tumour PDT employed such as interstitial PDT, and PDT-associated surgical resection, describing new light delivery devices. The role of dosimetry - one of the key factors behind successful brain tumour PDT - is discussed. This can be achieved by integrating results from in vivo studies. In this context, the development of new therapeutic photosensitizer delivery systems is also an area of significant research interest. Multifunctionality can be engineered into a single nanoplatform to provide tumour-specific detection, treatment, and follow-up. Such multitasking systems appear to be complementary to conventional technologies., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Many different types of fiber tips have been developed over the last few years to be used in endovenous laser ablation (EVLA) procedures. All these new but different tips claim a certain superiority over the other tips. Evidence for a best tip is however lacking. Four of these fiber tips have been compared in this article: (1) the bare fiber, (2) the Tulip-Tip, (3) the NeverTouch™ tip, and (4) the radially emitting tip. The aim of this paper is to provide information on the technical differences between these fiber tips and differences in their underlying heat transfer mechanisms. Although all tips are effective in the primary goal of EVLA, namely to occlude the incompetent vein, they differ in side effects, they differ in side effects, practicality, and cost. Although these new tips have improved EVLA, the perfect tip is not on the market yet.

A homogeneous and reproducible fluence delivery rate during clinical photodynamic therapy (PDT) plays a determinant role in preventing under- or overtreatment. PDT applied in dermatology has been carried out with a wide variety of light sources delivering a broad range of more or less adapted light doses. Due to the complexities of the human anatomy, these light sources do not in fact deliver a uniform light distribution to the skin. Therefore, the development of flexible light sources would considerably improve the homogeneity of light delivery. The integration of plastic optical fiber (POF) into textile structures could offer an interesting alternative. In this article, a textile light diffuser (TLD) has been developed using POF and Polyester yarns. Predetermined POF macrobending leads to side emission of light when the critical angle is exceeded. Therefore, a specific pattern based on different satin weaves has been developed in order to improve light emission homogeneity and to correct the decrease of side emitted radiation intensity along POF. The prototyped fabrics (approximately 100 cm(2): 5×20 cm) were woven using a hand loom, then both ends of the POF were coupled to a laser diode (5 W, 635 nm). The fluence rate (mW/ cm(2)) and the homogeneity of light delivery by the TLD were evaluated. Temperature evolution, as a function of time, was controlled with an infrared thermographic camera. When using a power source of 5 W, the fluence rate of the TLD was 18±2.5 mw/cm(2). Due to the high efficiency of the TLD, the optical losses were very low. The TLD temperature elevation was 0.6 °C after 10 min of illumination. Our TLD meets the basic requirements for PDT: homogeneous light distribution and flexibility. It also proves that large (500 cm(2)) textile light diffusers adapted to skin, but also to peritoneal or pleural cavity, PDTs can be easily produced by textile manufacturing processes., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Background: This clinical study reports our experience with endovenous laser treatment (ELT) in which external air cooling is used without classic tumescent anesthesia., Methods: Two hundred thirty-two patients underwent ELT under general sedation. In group A (n = 192), ELT was performed with air cooling but without the concurrent use of tumescent anesthesia. In group B (n = 40), patients were treated using the traditional tumescent technique. The parameters were similar for both groups: 980-nm diode laser, power of 15 W, and pulse duration of 1 second. The laser fiber and catheter were manually withdrawn in 3-mm increments. Ultrasound was performed to reevaluate vein closure at the end of surgery and 2 and 8 weeks and 1 year after. During follow-up, complications such as burns, dyschromia, pain, and dysesthesia, as well as time used for surgery were recorded., Results: A 96% closure rate was obtained in groups A and B at 2 and 8 weeks. This rate remained stable 1 year after the ELT procedure. Except for a higher percentage of ecchymoses in group B (55%) than in group A (0%) (p < 0.001), no significant differences were observed for complications. With external air cooling, ELT took 17.5 minutes to perform for the whole leg, compared with 38.5 minutes when using tumescent anesthesia (p < 0.05)., Conclusion: ELT surgery for the great saphenous vein can be safely performed using the air cooling method and is as efficacious as ELT done with tumescent anesthesia but takes significantly less time to perform., (© 2012 by the American Society for Dermatologic Surgery, Inc. Published by Wiley Periodicals, Inc.)

Gynecomastia is the most common breast pathology. Numerous excisions and liposuction techniques have been described to correct bilateral male breast enlargement. Recently, there has been a shift from the open approach to minimally invasive techniques. This article reports a 5-year experience using laser-assisted lipolysis (LAL) to treat gynecomastia, and describes the surgical technique. Between January 2006 and December 2010, a total of 28 patients with bilateral gynecomastia were treated with LAL. Patients had a mean age of 36.5 years (range 24 to 56 years). LAL was performed with a 980-nm diode laser (continuous emission, 15 W power, 8-12 kJ total energy per breast) after tumescent anesthetic infiltration. The breast was evaluated objectively by two physicians who compared chest circumference and photographs. Patients were also asked to score the results using a visual analogue scale: 75 to 100 (very good), 50-74 (good), 25 to 49 (fair) and 0 to 24 (poor). The postoperative period for all patients was incident-free. After 6 months, 18 patients (64.3%) scored the results as "very good", 6 as "good" (21.4%), 3 as "fair" (10.7%) and 1 "poor" (3.6%). Mean chest circumferences pre- and postoperatively were, respectively, 117.4 ± 11.1 cm and 103.3 ± 7.5 cm (p < 0.001), corresponding to a mean difference of 14.1 cm. Physicians scored the photographs as "very good" in 22 patients (78.6%), as "good" in five patients (17.9%), and as "fair" in one patient (3.6%). LAL in gynecomastia is safe and produces significant effects on fatty tissue, with a reduction in breast volume, together with significant skin tightening. Provided an appropriate amount of energy is delivered by an experienced operator, the results are both significant and consistent.

Background: The aim of this article is to summarize and review the proposed theories on the laser action during endovenous ablation., Methods: Laser mechanics and laser-tissue interaction are summarized from articles found in literature. Several theories, like the "steam bubble theory," the "direct contact theory," the "heat pipe," and "direct light energy absorption" are discussed., Results: The laser light emitted intraluminally can be absorbed, scattered, or reflected. Reflection is negligible in the near-infrared spectrum. By combining absorption and scattering, the optical extinction of different wavelengths related to different biological tissues can be determined. The direct contact of the fiber tip and the vein wall may be a way of destroying the vein wall, but results in ulcerations and perforations of the vein wall. Avoiding this contact, and allowing direct light absorption into the vein wall, results in a more homogenous vein wall destruction. If the energy is mainly absorbed by the intraluminal blood, the laser fiber will act as a heat pipe. Histological studies show that a more circumferential vein wall destruction can be obtained when the vein is emptied of its intraluminal blood. The use of tumescent liquid reinforces spasm of the vein and protects the perivenous tissue., Conclusion: Several factors play an important role in the mechanism of endovenous laser ablation. Direct energy absorption by the vein wall is the most efficient mechanism. It is important to empty the vein of its intraluminal blood and to inject tumescent liquid around the vein., (Copyright © 2012 Annals of Vascular Surgery Inc. Published by Elsevier Inc. All rights reserved.)

Background: Since the first studies by Apfelberg in 1994, laser lipolysis (LAL) has been on the rise. Laser lipolysis leads to reduced operator fatigue, excellent patient tolerance, quick recovery time, as well as the additional benefit of dermal tightening. This article reports a 5-year experience of LAL and underlines the potential evolutions of the technique., Methods: Between January 2006 and December 2010, 674 LAL procedures in 359 patients were performed at the Antoni De Gimbernat Foundation in collaboration with the French National Institute of Health and Medical Research (INSERM) U703. LAL was performed with a 980-nm diode laser after tumescent anaesthesia. The following laser settings were used: 600-μm optical fiber, continuous mode, power depending on individual body areas (18-40 W). The cumulative energy used for each area was recorded. Early and late complications were defined and reviewed for the whole series. Satisfaction was assessed by the patients using a visual analogue scale from 0 (unsatisfied) to 10 (highly satisfied)., Results: Mean cumulative energy ranged from 12 to 60 kJ. Ecchymoses were observed in all patients but resolved in less than 10 days. A touch up was needed in four patients to remove small cushions of fat missed. Mean patient satisfaction ranged from 6/10 to 9.5/10 depending on the treated area. Moreover, all patients reported they would be willing to undergo the procedure again, if needed., Conclusion: 980-nm LAL appears to be a safe, effective and reproducible alternative to conventional lipoplasty. However, refinements in dosimetry should be developed in order to optimise outcomes.

Background: Correction of prominent ears is a common plastic surgical procedure. We introduced a new non-invasive laser-assisted cartilage reshaping (LACR) technique as an alternative to invasive surgical otoplasty., Methods: Since our first report in 2006, 32 LACR procedures in 17 patients have been performed at the Antoni De Gimbernat Foundation in collaboration with the French National Institute of Health and Medical Research (INSERM) U703. For 15 patients, the procedure was bilateral, for the remaining 2 patients LACR was performed only on one side. The treatment consisted of seven stacked pulses (3 ms, 2 Hz, 84 J/cm(2) cumulative fluence) applied using a 4-mm spot hand piece. Early and late complications were defined and reviewed for the whole series. Satisfaction was assessed by the patients using a visual analogue scale from 0 (unsatisfied) to 10 (highly satisfied). The superior and middle cephaloauricular distances were prospectively evaluated., Results: Except for two cases of dermatitis, there were no early complications and no late complications (like keloids) in the series. The mean superior and middle cephaloauricular distances were, respectively, 12.3 ± 1.9 and 13.7 ± 1.6 mm compared to 17.8 ± 3.1 mm (p < 0.01) and 23.9 ± 1.9 mm (p < 0.01) before operation. Mean patient satisfaction was 8.6/10 with all patients reporting that they would be willing to undergo the procedure again, if required., Conclusion: LACR appears to be a safe and reproducible method for the treatment of protruding ears. Other applications of this technique, like laser assisted septal cartilage reshaping (LASCR) for septum deviation, have been recently described., (Copyright © 2011 Wiley Periodicals, Inc.)

Background: Superficial vascular anomalies such as port wine stains are commonly treated by selective photothermolysis (SP). The endovascular laser-tissue interactions underlying SP are governed by a photothermal response (thermocoagulation of blood) and a hemodynamic response (thrombosis). Currently it is not known whether the hemodynamic response encompasses both primary and secondary hemostasis, which platelet receptors are involved, and what the SP-induced thrombosis kinetics are in low-flow venules., Objectives: To (1) define the role and kinetics of primary and secondary hemostasis in laser-induced thrombus formation and (2) determine which key platelet surface receptors are involved in the hemodynamic response., Methods: 532-nm laser-irradiated hamster dorsal skin fold venules were studied by intravital fluorescence microscopy following fluorescent labeling of platelets with 5(6)-carboxyfluorescein. Heparin and fluorescently labeled anti-glycoprotein Ib-α (GPIbα) and anti-P-selectin antibodies were administered to investigate the role of coagulation and platelet receptors, respectively. Lesional sizes were quantified by software., Results: Laser irradiation consistently produced sub-occlusive thermal coagula. Thrombosis was triggered in all irradiated venules in a thermal coagulum-independent manner and peaked at 6.25min post-irradiation. Heparin decreased the maximum thrombus size and caused thrombosis to reach a maximum at 1.25min. Immunoblocking of GPIbα abated the extent of thrombosis, whereas immunoblocking of P-selectin had no effect., Conclusions: The hemodynamic response ensues the photothermal response in a thermal coagulum-independent manner and involves primary and secondary hemostasis. Primary hemostasis is mediated by constitutively expressed GPIbα but not by activation-dependent P-selectin., (Copyright © 2011 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.)

Background: The use of minimally invasive ablative techniques in the management of patients with low grade and localized prostate tumours could represent a treatment option between active surveillance and radical therapy. Focal laser ablation (FLA) could be one of these treatment modalities. Dosimetry planning and conformation of the treated area to the tumor remain major issues, especially when, several fibers are required. An effective method to perform pre-treatment planning of this therapy is computer simulation. In this study we present an in vivo validation of a mathematical model., Methods: The simulation model is based on finite elements method (FEM) to solve the bio-heat and the thermal damage equations. Laser irradiation was performed with a 980 nm laser diode system (5 W, 75 s). Light was transmitted using a cylindrical diffusing fiber inserted inside a preclinical animal prostate cancer model induced in Copenhagen rats. Non-enhanced T2-weighted and dynamic gadolinium-enhanced T1-weighted MR imaging examinations were performed at baseline and 48 hours after the procedure. The model was validated by comparing the simulated necrosis volume to the results obtained in vivo on (MRI) and by histological analysis. 3 iso-damage temperatures were considered 43° C, 45° C and 50° C., Results: The mean volume of the tissue necrosis, estimated from the histological analyses was 0.974 ± 0.059 cc and 0.98 ± 0.052 cc on the 48 h MR images. For the simulation model, volumes were: 1.38 cc when T = 43° C, 1.1 cc for T = 45°C and 0.99 cc when T = 50 C°., Conclusions: In this study, a clear correlation was established between simulation and in vivo experiments of FLA for prostate cancer.Simulation is a promising planning technique for this therapy. It needs further more evaluation to allow to FLA to become a widely applied surgical method.

Background: Since the initial work of Jacobson and Suarez in 1960, microsurgery has evolved greatly. In 2009, we reported our clinical experience with 1.9 µm diode laser-assisted vascular microanastomoses (LAMA) for free flap reconstruction. In this report, the ongoing study is now expanded to include 11 additional procedures which were analyzed prospectively with a focus on the duration of the LAMA technique., Methods: In total, 40 clinical procedures with LAMA have been performed since 2005. Mean follow-up was 3.3 years (range 0.5-5.5 years). Among those, 11 procedures were performed and prospectively analyzed during the period 2008-2009. LAMA was performed with a 1.9 µm diode laser after placement of equidistant stitches. For vessels size <1.5 mm, the following laser parameters were used: spot size 400 µm, five spots for each wall, power 125 mW, arterial/venous fluence 100/90 J/cm(2) (spot duration 1/0.9 seconds)., Results: For the last observed 11 procedures, mean occlusion time of the flap arterial and venous anastomoses was 5.4 ± 0.4 and 6.8 ± 0.7 minutes respectively. One anastomosis required a secondary laser application. Arterial and venous patency rates were 100% at the time of surgery. The success rate for the 11 procedures was 100%. The global success rate of the series (97.5%) is discussed and compared with the literature., Conclusion: The success rates for reconstructive free flap surgery realized with LAMA appear excellent. Technical innovation will most likely lead to widespread use of the handpiece laser in the operating room., (Copyright © 2011 Wiley-Liss, Inc.)

Background and Objectives: Bone vascularization is a key factor in the bone healing process following X-ray irradiation. Preserving the vascular network from X-ray-induced injury is a relevant approach in the promotion of bone healing. Previously, we developed a protocol of laser preconditioning (810 nm diode laser, 36 J/cm²) prior to X-ray radiation (18.75 Gy) which protects the bone vascular network from deleterious effects of X-ray radiation. The aim of this present work is to characterize the effects of laser preconditioning on the bone through a morphological analysis of vascular parameters., Materials and Methods: Digital images of the vascular plexus were taken through an optical bone chamber which was implanted onto the calvaria of rabbits. Bespoke software was used for the quantification of the vessels (classified in four groups according to their diameter), vessel length, and number of nodes at weeks 0, 4, and 8. Twenty rabbits were divided into four groups: control group #1 (n = 5); laser group #2 (n = 5). X-ray radiation group #3 (n = 5), laser preconditioning 24 hours prior to X-ray radiation group #4 (n = 5)., Results: The bone vascular network was stable for groups #1 and #2. Statistical analysis showed a significant reduction of each observed vascular parameter for groups #3 and #4. In the laser preconditioned group #4 the loss was less marked than in the X-ray group #3, especially for large vessels (diameter >50 µm)., Discussion and Conclusion: We provide in vivo microcirculatory evidence to support the concept of laser preconditioning of bone. A computer-based semi-automatic system is described to quantify superficial bone vascular network parameters that had been treated by laser preconditioning prior to X-ray radiation. Laser preconditioning significantly attenuates the deletion of the superficial bone vascular network irradiated by X-ray, especially concerning large diameter vessels., (© 2010 Wiley-Liss, Inc.)

Background and Objectives: Cosmetic results after skin surgery are essential for patient satisfaction. Since 1983, different lasers have been used to accelerate and improve the healing process in surgical scars. This article aims to review the different laser therapies available for preventive treatment of scars., Methods: A Medline literature search was performed on laser scar prevention with cross-referencing., Results: Different lasers have been used for the preventive treatment of scars. Both the pulsed dye laser (PDL) (585 and 595 nm) and laser-assisted skin healing (LASH) (810 nm) provide excellent results. The mechanism of action, side effects and clinical applications are carefully reviewed in this article. Ease of the procedure, practical application of the laser and price of the therapy are then discussed for both types of laser., Conclusion: Two different lasers have mostly been used for the preventive treatment of scars. It appears that the use of laser energy in the early phase of the healing process is critical in the improvement of the resulting scar. More research is still warranted to understand the mechanisms of action potentially leading to scarless healing. Finally, the widespread, routine use of this technique will largely depend on the ease of use of the system.

Background: Microvascular surgery has become an important method for reconstructing surgical defects resulting from trauma, tumors, or burns. The most important factor for successful free flap transfer is a well-executed anastomosis. This study was performed to review the authors' experience with a 1.9-microm diode laser in microsurgery, with special attention to outcomes and performance of the technique., Methods: Between January of 2005 and December of 2007, 27 patients underwent microsurgery with a 1.9-microm diode laser at the authors' institute. The patients had a mean age of 31 years (range, 2 to 59 years); 14 patients were women and 13 patients were men. This technique was used for digital replantations (n = 2) and for free flap transfer (n = 27). Causes of the defects were trauma (n = 14), tumor (n = 9), congenital (n = 2), burn (n = 1), infection (n = 1), arthritis (n = 1), and dog bite (n = 1). Laser-assisted microvascular anastomosis was performed with a 1.9-microm diode laser after placement of equidistant stitches. The following parameters were used: spot size, 400 microm; power, 125 mW; time depending on vessel size (0.8 to 1.8 mm); and fluence varying from 70 to 200 J/cm., Results: Three surgical revisions following hematoma and one rupture of the arterial anastomosis leading to a free deep inferior epigastric perforator flap necrosis resulting from high-dose radiotherapy before surgery occurred after laser-assisted microvascular anastomosis, accounting for an overall success rate of 96.6 percent., Conclusion: This study reports the numerous benefits of the technique: easier performance of vascular anastomosis with difficult access, decrease of reperfusion bleeding and complications, and a short learning curve.

Background and Objectives: Liposuction continues to be one of the most popular procedures performed in cosmetic surgery. As the public's demand for body contouring continues, laser lipolysis has been proposed to improve results, minimize risk, optimize patient comfort, and reduce the recovery period. Mathematical modeling of laser lipolysis could provide a better understanding of the laser lipolysis process and could determine the optimal dosage as a function of fat volume to be removed., Study Design/materials and Methods: An Optical-Thermal-Damage Model was formulated using finite-element modeling software (Femlab 3.1, Comsol Inc). The general model simulated light distribution using the diffusion approximation of the transport theory, temperature rise using the bioheat equation and laser-induced injury using the Arrhenius damage model. Biological tissue was represented by two homogenous regions (dermis and fat layer) with a nonlinear air-tissue boundary condition including free convection. Video recordings were used to gain a better understanding of the back and forth movement of the cannula during laser lipolysis in order to consider them in our mathematical model. Infrared video recordings were also performed in order to compare the actual surface temperatures to our calculations. The reduction in fat volume was determined as a function of the total applied energy and subsequently compared to clinical data reported in the literature., Results: In patients, when using cooled tumescent anesthesia, 1064 nm Nd:YAG laser or 980 nm diode laser: (6 W, back and forth motion: 100 mm/s) give similar skin surface temperature (max: 41 degrees C). These measurements are in accordance with those obtained by mathematical modeling performed with a 1 mm cannula inserted inside the hypodermis layer at 0.8 cm below the surface. Similarly, the fat volume reduction observed in patients at 6-month follow up can be determined by mathematical modeling. This fat reduction depends on the applied energy, typically 5 cm3 for 3000 J. At last, skin retraction was observed in patients at 6-month follow up. This observation can be easily explained by mathematical modeling showing that the temperature increase inside the lower dermis is sufficient (48-50 degrees C) to induce skin tightening, Discussion and Conclusion: Laser lipolysis can be described by a theoretical model. Fat volume reduction observed in patients is in accordance with model calculations. Due to heat diffusion, temperature elevation is also produced inside the lower reticular dermis. This interesting observation can explain remodeling of the collagenous tissue, with clinically evident skin tightening. In conclusion, while the heat generated by interstitial laser irradiation provides stimulate lipolysis of the fat cells, the collagen and elastin are also stimulated resulting in a tightening in the skin. This mathematical model should serve as a useful tool to simulate and better understand the mechanism of action of the laser lipolysis.

The putative features of the (endo)vascular photothermal response, characterized by laser-induced thermal denaturation of blood and vessel wall constituents, have been elucidated individually, but not simultaneously in dynamic, isolated in vivo systems. A hamster dorsal skin fold model in combination with brightfield/fluorescence intravital microscopy was used to examine the effect of laser pulse duration and blood flow velocity on the size of the thermal coagulum, its attachment behavior, and laser-mediated vasomotion. The size of the coagulum and the extent of vasoconstriction and latent vasodilation were proportional to the laser pulse duration, but pulse duration had no effect on coagulum attachment/dislodgement. Blood flow velocity exhibited no significant effect on the studied parameters. The (endo)vascular photothermal response is governed predominantly by laser energy deposition and to a marginal extent by blood flow velocity.

Background and Objectives: Endovenous laser treatment (ELT) has been proposed as an alternative in the treatment of reflux of the great saphenous vein (GSV) and small saphenous vein (SSV). Numerous studies have since demonstrated that this technique is both safe and efficacious. ELT was presented initially using diode lasers of 810 nm, 940 nm, and 980 nm. Recently, a 1,320-nm Nd:YAG laser was introduced for ELT. This study aims to provide mathematical modeling of ELT in order to compare 980 nm and 1,320 nm laser-induced damage of saphenous veins., Study Design/materials and Methods: The model is based on calculations describing light distribution using the diffusion approximation of the transport theory, the temperature rise using the bioheat equation, and the laser-induced injury using the Arrhenius damage model. The geometry to simulate ELT was based on a 2D model consisting of a cylindrically symmetric blood vessel including a vessel wall and surrounded by an infinite homogenous tissue. The mathematical model was implemented using the Macsyma-Pdease2D software (Macsyma, Inc., Arlington, MA). Calculations were performed so as to determine the damage induced in the intima tunica, the externa tunica and inside the peri-venous tissue for 3 mm and 5 mm vessels (considered after tumescent anesthesia) and different linear endovenous energy densities (LEED) usually reported in the literature., Results: Calculations were performed for two different vein diameters: 3 mm and 5 mm and with LEED typically reported in the literature. For 980 nm, LEED: 50 to 160 J/cm (CW mode, 2 mm/second pullback speed, power: 10 W to 32 W) and for 1,320 nm, LEED: 50 to 80 J/cm (pulsed mode, pulse duration 1.2 milliseconds, peak power: 135 W, repetition rate 30 Hz to 50 Hz)., Discussion and Conclusion: Numerical simulations are in agreement with LEED reported in clinical studies. Mathematical modeling shows clearly that 1,320 nm, with a better absorption by the vessel wall, requires less energy to achieve wall damage. In the 810-1,320-nm range, blood plays only a minor role. Consequently, the classification of these lasers into hemoglobin-specific laser wavelengths (810, 940, 980 nm) and water-specific laser wavelengths (1,320 nm) is inappropriate. In terms of closure rate, 980 nm and 1,320 nm can lead to similar results and, as reported by the literature, to similar side effects. This model should serve as a useful tool to simulate and better understand the mechanism of action of the ELT., ((c) 2007 Wiley-Liss, Inc)

Background/aim: Subvisible micropulse diode laser photocoagulation localises retinal laser damage because brief micropulses allow little time for heat conduction to spread temperature rise from the retinal pigment epithelium to the neural retina. Treatment power is often chosen as a multiple of that needed for visible continuous wave lesions. The authors measured clinical laser powers needed for visible end point micropulse and continuous wave diode laser retinal photocoagulation., Methods: Six parallel rows of 10 diode laser (810 nm) burns were made in the superior peripheral retina of six consecutive patients undergoing their initial frequency doubled Nd:YAG (532 nm) panretinal photocoagulation for proliferative or severe non-proliferative diabetic retinopathy. All photocoagulation exposures were 125 microm in retinal diameter and 0.2 seconds in duration. Micropulse exposures were performed with 500 Hz, 0.3 ms micropulses. The minimal power needed (1) for visible continuous wave diode photocoagulation was determined from two adjacent rows of laser lesions and (2) for visible micropulse diode photocoagulation from four additional adjacent rows of laser lesions. Fluorescein angiograms and red-free fundus photographs were obtained immediately and 6 days after laser photocoagulation in each patient. Calculations were performed to determine the extent to which clinical parameters exceeded ANSI Z136.1-2000 maximal permissible exposure (MPE) levels for laser exposure., Results: Continuous wave and micropulse lesions typically required 300 mW (60 mJ) and 1800 mW (54 mJ), respectively. Visible continuous wave and micropulse lesions exceeded MPE levels by multiples of 36 x and 133 x, respectively. Laser energies were similar for visible continuous wave and micropulse lesions., Conclusion: Visible micropulse lesions require 6 x more power but roughly the same energy as visible continuous wave lesions. No significant difference was demonstrable in the minimal power needed for photographically and angiographically apparent diode micropulse lesions. MPE levels are designed to provide a 10 x safety margin. This safety margin was 3.7 x greater for micropulse than continuous wave diode laser photocoagulation.

Background and Objectives: Endovenous laser treatment (ELT) has been recently proposed as an alternative in the treatment of reflux of the Great Saphenous Vein (GSV) and Small Saphenous Vein (SSV). Successful ELT depends on the selection of optimal parameters required to achieve an optimal vein damage while avoiding side effects. Mathematical modeling of ELT could provide a better understanding of the ELT process and could determine the optimal dosage as a function of vein diameter., Study Design/materials and Methods: The model is based on calculations describing the light distribution using the diffusion approximation of the transport theory, the temperature rise using the bioheat equation and the laser-induced injury using the Arrhenius damage model. The geometry to simulate ELT was based on a 2D model consisting of a cylindrically symmetric blood vessel including a vessel wall and surrounded by an infinite homogenous tissue. The mathematical model was implemented using the Macsyma-Pdease2D software (Macsyma Inc., Arlington, MA, USA). Damage to the vein wall for CW and single shot energy was calculated for 3 and 5 mm vein diameters. In pulsed mode, the pullback distance (3, 5 and 7 mm) was considered. For CW mode simulation, the pullback speed (1, 2, 3 mm/s) was the variable. The total dose was expressed as joules per centimeter in order to perform comparison to results already reported in clinical studies., Results: In pulsed mode, for a 3 mm vein diameter, irrespective of the pullback distance (2, 5 or 7 mm), a minimum fluence of 15 J/cm is required to obtain a permanent damage of the intima. For a 5 mm vein diameter, 50 J/cm (15W-2s) is required. In continuous mode, for a 3 mm and 5 mm vein diameter, respectively 65 J/cm and 100 J/cm are required to obtain a permanent damage of the vessel wall. Finally, the use of different wavelengths (810 nm or 980 nm) played only a minor influence on these results., Discussion and Conclusion: The parameters determined by mathematical modeling are in agreement with those used in clinical practice. They confirm that thermal damage of the inner vein wall (tunica intima) is required to achieve the tissue alterations necessary in order to lead the vein to permanent occlusion. However, in order to obtain a high rate of success without adverse events, the knowledge of the vein diameter after tumescent anesthesia is recommended in order to use the optimal energy. As clearly demonstrated by our calculations, both pulsed and continuous mode operations of the laser can be efficient. An interesting observation in our model is that less amount of energy is required in pulsed mode than in continuous mode. Damaging the vein sequentially along its entire length may lead to permanent occlusion. However, the pulsed mode requires a very precise positioning of the fiber after each pullback and the duration of the treatment is much longer. For these reasons, continuous irradiation seems to be preferred by most clinicians. This model should serve as a useful tool to simulate and better understand the mechanism of action of the ELT.

Background and Objectives: Effective laser treatment of leg veins remains a major challenge. The present study examined the safety and efficacy of a new technology for leg vein treatment combining 900 nm diode laser with radiofrequency (RF) current., Study Design/materials and Methods: Forty patients, skin types II-IV, received a maximum of three treatments on 1-4 mm leg veins at 2-week intervals with a 900 nm diode laser (250 millisecond exposure time, average fluence 60 J/cm2) and RF (energy 100 J/cm3). Results were assessed after each treatment and at 2 and 6 months after the final session. Patients rated their satisfaction with the clinical outcome on a five-item scale. Clinician and computer analysis of the clinical photography was also performed, in addition to histological assessment., Results: One or two sessions were required in the majority of patients. Shortly after treatment, histology revealed contracted vessels with perivascular edema. Side effects were extremely rare. The clinician 2- and 6-month assessments showed that 70% and 82.5% of subjects, respectively, achieved over 50% clearance, with patient and computer assessments lower and slightly higher, respectively. Treatments showed greater efficacy on thicker vessels and in the darker skin types., Conclusions: The success of the treatment, minimal side effects, and patient comfort suggest that this combination is an effective, safe technique for leg vein treatment. When compared to previous studies using diode laser alone, the very low fluence needed to achieve vessel clearance emphasizes the role of RF energy., (2006 Wiley-Liss, Inc.)

Background: The efficacy of the 800-nm diode laser system in clearing leg veins was analyzed subjectively and objectively in a variety of leg veins., Methods: A total of 10 women (age 25-55 years, skin types II-IV) with a variety of leg vein types were treated with an 800-nm diode laser. A sequence of pulses (5-8 stacked pulses, pulse duration 50 milliseconds, delay 50 milliseconds) was applied on a 3-mm spot (210-336 J/cm2 fluence, depending on vessel size). Treatment on the same vein was performed at intervals of 2 months until complete clearance was achieved (maximum: 3 treatments). The results were assessed at 6 months from the last treatment. Patients evaluated their subjective improvement by means of a questionnaire to elicit the satisfaction index. In an independent objective assessment, the clearance index was based on the pretreatment and posttreatment clinical photography, also analyzed by a computer program., Results: All patients completed the trial with mild but transient side effects. The patient 6-month assessments for very good, good, fair, poor, and worse were 1, 5, 3, 1, and 0, respectively. For the clinician-assessed clearance index, the numbers for the same grades were 2, 6, 2, 0, and 0, and for the computer assessment they were 1, 6, 2, 1, and 0. No patient scored worse in any assessment. The overall satisfaction index and clinician and computer clearance indexes were 60%, 80%, and 70%, respectively., Limitations: No control group could be obtained in this study., Conclusions: The 800-nm diode laser as used in the study may well offer an effective treatment method for leg veins that is comparatively pain and side-effect free. Best results were obtained in vessels of 3 to 4 mm in diameter located on the thigh, and in patients with phototype III skin. No correlation was seen between results and patient age.

Background and Objectives: For photodynamic therapy (PDT) or transpupillary thermotherapy (TTT) lasers, long irradiation time (typically 1 minute or longer) is used and a large area of retina is treated. Consequently, the power stability but also the light distribution within the laser beam plays a major role. This study aimed to evaluate beam intensity profiles produced by several PDT and TTT lasers., Study Design/materials and Methods: A beam profile analyzer (Cohu 4812 camera connected to a LPA-300PC, Spiricon, Logan, UT) was used to compare the beam profiles of PDT lasers: OPAL (Lumenis, USA); ACTIVIS (Quantel Medical, France), VISULAS (Zeiss, Germany). Spots of 2, 3, 4, and 5 mm were tested with each laser. Similarly, TTT lasers: OCULIGHT SLx (Iridex, CA) and IRIDIS trade mark (Quantel Medical, France) were evaluated with 2 and 3 mm spot diameter and power ranging from 200 to 1,000 mW., Results: PDT lasers: OPAL had a "top hat" and homogeneous profile whatever the spot size. Numerous micro-spikes and micro-nadirs of power were observed with the ACTIVIS and the VISULAS. TTT lasers: for the IRIDIS the beam shape was rather gaussian, but the homogeneity was reduced by micro-spikes of power. With the OCULIGHT Slx the beam shape was rather top hat and only few micro-spikes or micro-nadirs of power could be disclosed., Discussion: The literature tends to prove that the shape and homogeneity of the beam profile could play a role on the efficacy of the treatment., Conclusion: Since PDT and TTT lasers display different beam profiles, this parameter should be carefully evaluated when performing clinical evaluations of PDT or TTT treatments., (Copyright 2005 Wiley-Liss, Inc.)

Background and Objectives: Carbon dioxide (CO2) and Er:YAG lasers are commonly used for laser skin resurfacing. In demonstrating their efficacy, intra- and interoperator variability may be important. In attempting to solve this problem, a new concept was developed which combines a previous application of an exogenous chromophore onto the skin in a standardized way (Chromofilm) and irradiation with a millisecond, low-power pulsed laser., Materials and Methods: This study aimed to evaluate this new concept in vivo in human skin using a 532-nm Nd:YAG laser connected to a scanner using the following parameters: 532 nm, 2W, 1-mm spot size, 30-mm2 hexagonal surface irradiation and 50-120-ms pulse duration. The laser irradiation was performed both 15 h and 1 h prior to the facelift procedure. Tissue samples were examined histologically to determine the injury depth using nitroblue-tetrazolium chloride (NBTC) staining, haematoxylin-eosin staining and Masson's staining., Results: Morphometric analysis of histological preparations showed that the depth of injury was dose-dependent: 50-ms pulse duration induced total epidermis ablation and fine dermal coagulation; 120-ms pulse duration induced dermal coagulation down to 120 microns. No residual carbon film was observed on histologic sections., Conclusion: Laser skin resurfacing using a 532-nm laser irradiation after application of a carbon film transfer is an effective method for skin resurfacing. With this new galenic approach (Chromofilm), the control of all parameters (thickness, chromophore concentration and distribution) can be achieved to predict the thermal injury obtained after laser irradiation.

Background: Many persons seek to decrease hair growth and hair density. Although a variety of epilating methods are available, a practical and permanent hair removal treatment is needed., Objective: The purpose of this study was to evaluate a new method of obtaining a better penetration depth of dyes into the follicular duct. By increasing both the quantity and the penetration depth of dye into the follicular duct, the efficacy of laser hair removal could be improved., Methods: Dye penetration depth was assessed histologically after the use of formulations containing rhodamine-6G-loaded microspheres dispersed into two different silicones. Each formulation was tested on two hairless rats. After formulation application, dye diffusion was realized by applying ethanol on the skin to extract rhodamine-6G from microspheres., Results: In all our experimental conditions follicular targeting occurred. No difference in the penetration depth of rhodamine-loaded microspheres was seen between our different silicone formulations. After ethanol application, the penetration of rhodamine-6G into the hair follicle was considerably increased by the fluid silicone vehicle (vs volatile silicone)., Conclusion: This new galenical approach aims to transport a dye into the hair follicle specifically and deeply. By using adequate laser, the efficiency of laser hair removal could be increased.

Background and Objectives: The aim of the study was to evaluate the feasibility of retinal thermal damage assessment in a rabbit eye model by using laser-induced release of liposome-encapsulated dye., Study Design/materials and Methods: After anesthesia, thermosensitive liposomes (DiStearoyl Phosphatidyl Choline: DSPC) loaded with 5,6-carboxyfluorescein were injected intravenously to pigmented rabbits. Retinal photocoagulations were performed with a 810nm diode laser (P=100-400 mW, laser spot=500 microm, 1s) (OcuLight, IRIS Medical Instruments, Mountain View, CA). Fluorescence measurements in the area of the laser exposures were then realized with a digitized angiograph (CF-60UVi, Canon-Europe, The Netherlands; OcuLab, Life Science Resources, UK)., Results: Fluorescent spots were observed for power ranging from 100 +/- 5 mW to 400 +/- 5 mW. The fluorescence intensity increased linearly with the power and reached a plateau at 280 +/- 5 mW. The fluorescence intensity was correlated to the maximum temperature at the center of the laser spot with a linear increase from 42 +/- 3 degrees C to 65 +/- 3 degrees C. These results are in agreement with our two previous studies with DSPC liposomes for temperature measurements in a tissue model and then in a vascular model., Conclusion: This preliminary study demonstrates the possibility of a laser-induced release of liposome-encapsulated dye for a quantification of diode laser induced thermal damage in ophthalmology. Such a method could be useful for a real-time monitoring of laser photocoagulation for conditions such as choroidal neovascular membranes when a precise thermal damage is required near the foveolar area.

Background and Objectives: Although laser skin resurfacing performed with CO(2) or Er:YAG lasers is efficient, side effects such as prolonged postoperative erythema, delayed healing, scarring, and pigmentation, have been reported. These side effects are due to skin characteristics but also to variations of the thermal effects associated with laser skin resurfacing. The study aimed to evaluate a new laser resurfacing method based on a previous topical application of an exogenous chromophore in order to have reproducible thermal effects., Materials and Methods: Exogenous chromophore consisted in carbon dispersed and mixed with film-forming polymers and water. The resultant solution was applied to the skin surface using an airbrush. Experimental evaluation was performed in vivo on hairless rat skin using the following parameters (532 nm, 2.7 W, 1 mm, 50-200 ms, 17.2-68.8 J/cm(2), single pass). Skin biopsies were taken to evaluate histological changes and to quantify epidermis ablation and dermal coagulation depth. Wound healing was followed up during 10 days., Results: Total epidermis ablation was achieved with all pulse durations used. Dermal coagulation depth increased as a function of exposure time. Scar formation was correlated with dermal coagulation depth., Conclusion: The concept of applying a carbon-based solution onto skin in order to obtain laser light conversion into heat followed by heat transfer to the tissue is valid for laser skin resurfacing. By selecting exposure time, the thermal effects are predictable and dermal coagulation depth can be either that observed with a Er:YAG laser or that obtained with a CO(2) laser. Moreover, frequency doubled Nd:YAG laser, already used in dermatology for angiodysplasias treatment, could be easily used for resurfacing of periorbital or perioral zones., (Copyright 1999 Wiley-Liss, Inc.)

A major problem with endometriosis is the detection of microscopic and atypical lesions. An incomplete surgical eradication may lead to recurrence of the disease. This study aimed to investigate the diagnostic improvement of endometriosis by the use of tamoxifen-eosin induced fluorescence. The experimental study was performed on surgically induced endometriosis in the rabbit. Endometriosis was induced by grafting endometrium onto the broad ligament in 10 rabbits. After 5 weeks, the fluorescence of excised endometriosis was studied after systemic injection of tamoxifen and local application of eosin. Healthy peritoneal samples served as controls. The fluorescence of endometriotic foci was also compared with (n = 5) or without (n = 5) tamoxifen. Fluorescence excitation was carried out using a 150 W filtered lamp connected to an optical fibre. Fluorescence emission was measured using an optical fibre connected to a spectrofluorometer. Spectral analysis showed a specific fluorescence of endometriosis 72 h after systemic injection of tamoxifen and eosin application. This result is explained by binding to oestrogen receptors of tamoxifen which was protonized to form an ionic pair with eosin. Histological study of samples from the graft of endometrial tissue showed that experimental endometriosis had developed in eight out of the 10 rabbits. However, the fluorescence was not significantly different among the 10 rabbits. This observation was in accordance with previous studies in which endometriosis was confirmed by routine histological techniques or electron microscopy in 70-80% of cases. Consequently, the fluorescence of the two samples which did not present histological evidence of endometriosis indicates the presence of microscopic endometriotic foci.(ABSTRACT TRUNCATED AT 250 WORDS)

The present in vivo study was undertaken to evaluate the patency rate and histological appearance of 30 venous anastomoses and 30 carotid anastomoses in Wistar rats using a laser. An argon laser was used with the following parameters: power, 100 mW; time, 3 seconds; continuous mode; spot, 200 microns (fluence, 950 J/cm2; irradiance. 320 W/cm2). The macroscopic appearance and patency rate were evaluated at different postoperative intervals (30 days and 60 days). In the venous group, the patency rate was 100% with no saccular pseudo-aneurysm. In the arterial group, the patency rate was 93% with three saccular pseudo-aneurysms and two thromboses. Histological studies noted slight and transitory modifications of the media in the arterial group. In the venous group, the modifications appeared under the endothelium. Since the procedure was similar in both groups, the lack of pseudo-aneurysm formation in the venous group can be explained by a lower intravascular pressure.

The aim of this study was to determine efficient parameters for an argon laser (spot diameter = 200 microns) to obtain and reproduce vessel anastomoses. It was performed in two groups of Wistar rats. In the first group (89 Laser impacts on 10 carotids), the fluence was continuously adjusted from 30 to 3,000 J/cm2 in order to determine efficient sets of parameters (power from 90-200 mW, pulse duration from 0.1 to 5 seconds, pulsed or continuous mode). In the second group, 30 end-to-end carotid anastomoses were performed. The results were evaluated by macroscopic thermal, and histological studies. The second group proved the efficiency of the selected parameters. Vessel welding was obtained with 100 mW, 3 seconds, continuous mode (fluence = 950 J/cm2, irradiance = 320 W/cm2) for a mean temperature of 77 degrees C corresponding to collagen denaturation. In the second group the patency rate was 93% (28/30) with three pseudo-aneurisms and two thromboses. Histological studies noted slight modifications of the media.