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  • 1
    ISSN: 1433-7347
    Keywords: Keywords Laser ; Synovectomy ; Rheumatoid arthritis ; Animal ¶model ; Photodynamic therapy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Sports Science
    Notes: Abstract Photodynamic laser therapy has been shown to be a new method for the treatment of synovitis in various animal models. Its principle is the accumulation of a photosensitizing drug in the inflamed synovium which is destroyed by photoactivation of the drug. In the present animal study we demonstrate the effect of a second-generation photosensitizer and suggest a concept for light dosimetry within the joint. We used 38 inbred rabbits for the IgG-induced arthritis model; ¶2 mg/kg of the benzoporphyrin derivative monoacid ring-A (BPD-MA) Verteporfin were administered 3 h before irradiation, which was performed using a 690-nm diode laser coupled to quartz glass fiber with a cylinder diffusor tip at a total light energy of either 180 or 470 J. During irradiation specific fluorescence of BPD-MA was monitored using a spectroscopy unit. The effect of the photodynamic laser therapy was documented grossly and histologically after 1 week. Within the 470 J-group a complete necrosis of the inflamed synovium was observed. The bradytrophic structures of the joint, however, remained unchanged. Throughout the 180 J-group the extent of necrosis was minor. During irradiation the tissue fluorescence of BPD-MA showed a dose-dependent decrease. Using BPD-MA as a photosensitizer a highly selective and minimal invasive synoviorthesis can be performed. At a dose of 2 mg/kg the histological effect depends on the light dose. For optimum efficacy a total energy of 470 J seems favorable. Online fluorescence detection can be used to monitor the effect of light administration. For dosimetry therefore an online tissue fluorescence detection may represent a technical solution.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1433-7347
    Keywords: Key words Arthroscopy ; Holmium:YAG laser ; Laser
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Sports Science
    Notes: Abstract The results of 320 arthroscopic procedures are reported here, in which laser surgery using the holmium:YAG laser is compared with conventional mechanical methods. The patients were followed-up during a 2-year period and the data analyzed in a prospective study. The following knee injuries were included: meniscal lesion, chondromalacia, combined meniscal/cartilage lesion, rheumatoid synovialitis and patellofemoral pain syndrome. Because strict inclusion criteria were used, the patient collective is homogenous. Gender, age, injured side, intrasurgical diagnosis, and the initial values of the Lysholm score (modified after Klein) are congruous. After 2 years, the results of the laser collective were significantly improved, whereas the results for the conventional collective, especially for chondromalacia and synovialitis, did not show the same improvement. Analysis of the effect of various instruments and the laser system itself show differing results for the various knee disorders. The hemostatic effect of the holmium:YAG laser was excellent during surgery of all knee disorders, including surface treatment. Operating time for laser surgery was not prolonged, in contrast to what is often claimed. This study shows that chondromalacia, combined meniscal-cartilage lesions, and chronic rheumatoid synovialitis are treated more effectively and with better results with the holmium:YAG laser than with conventional arthroscopic methods. Furthermore, laser treatment of lateral retinacular release can be considered to be better than mechanical techniques. No significant advantage can be found for using the laser during meniscectomy. Lasers are useful for treating smaller, hard-to-reach joints and lower the risk of iatrogenic cartilage damage. The holmium:YAG laser is a suitable instrument for arthroscopic surgery.
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  • 3
    ISSN: 1433-7347
    Keywords: Key words Synovectomy ; Rheumatoid arthritis ; Photodynamic laser therapy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Sports Science
    Notes: Abstract The introduction of arthroscopic techniques has improved the surgical therapy of rheumatoid arthritis. The additional application of the holmium:yttrium aluminum garnet (Ho:YAG) laser likewise holds great promise by providing complete hemorrhagic control. Unfortunately, a minimally invasive solution for use in smaller joints has not yet emerged. The present study describes the possible treatment of these joints by means of photodynamic laser therapy. Cell culture studies with human synovial fibroblasts obtained from patients with rheumatoid arthritis have demonstrated a cytotoxic effect after administration of Photosan-3 as a photosensitizer and subsequent laser irradiation at 630 nm. For the in vivo studies, IgG-induced arthritis in rabbits, which is histologically consistent with the proliferative phase of rheumatoid arthritis, was used as the animal model. The histologic picture following photodynamic laser therapy with Photosan-3 revealed complete synovial destruction which also extended to the border of the subjacent joint capsule. In contrast, bradytrophic structures, e.g. cartilage, menisci, and ligaments, remained unchanged at both the macroscopic and microscopic levels. Therefore, photodynamic laser therapy can be considered a new method in the surgical treatment of inflammatory disease of the synovial membrane. It has the advantage of being minimally invasive, while offering a high degree of efficacy and selectivity.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1434-3924
    Keywords: Schlüsselwörter PDT ; Laser ; Tiermodell ; Key words PDT ; Laser ; RA ; Animal model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: The principle of photodynamic therapy (PDT) for rheumatoid arthritis consists in specifically concentrating a drug (photosensitizer) in the synovium. Subsequent activation of the photosensitizer by means of a laser leads to a cytotoxic effect. The practicability of PDT was tested in an animal model of IgG-induced arthritis in rabbits. Photosan-3, 5-aminolevulinic acid and BPD-MA were administered intraarticularly or intravenously. In this model, concentration of the photosensitizer in the synovial lining cells, the lymphoid infiltrate, and the skin was seen. After laser irradiation a selective demarcation and destruction of the synovium by prior administration of Photosan-3, not constant by BPD-MA and without therapeutic effect by 5-aminolevulinic acid, was observed. In contrast, bradytrophic tissues such as cartilage, meniscus, and ligament structures were changed neither macroscopically nor microscopically in all series. PDT thus offers ideal preconditions for minimal invasive treatment of chronic inflammatory joint diseases because of its selectivity and efficacy. Photodynamic laser therapy can be considered a new method in the surgical treatment of inflammatory disease of the synovial membrane.
    Notes: Die rheumatische Entzündung nimmt ihren Ausgang vom entzündlichen Pannusgewebe, das die betroffenen Gelenke mit ihren Kapseln, Sehnen und Bändern zerstört. Bei der photodynamischen Lasertherapie (PDT) für die chronische Polyarthritis erfolgt in der Synovialis die selektive Anreicherung eines Medikaments (Photosensibilisator), dessen nachfolgende Laseraktivierung einen zytotoxischen Effekt bewirkt. Die Durchführbarkeit einer photodynamischen Therapie wurde am Tiermodell der IgG-induzierten Arthritis des Kaninchens erprobt. Dieses Tiermodell entspricht histologisch den proliferativen Phasen einer Rheumatoiden Arthritis. Als Photosensibilisatoren wurden 3 verschiedene Substanzen getestet (Photosan-3, 5-Aminolävulinsäure und das Benzoporphyrinderivat BPD-MA). Eine spezifische Anreicherung der Photosensibilisatoren in der Deckzellschicht und im lymphoplasmazellulären Infiltrat wurde beobachtet. Nach Laserbestrahlung des Gelenks zeigte sich eine vollständige Zerstörung der Synovialis bis zur darunter liegenden Gelenkkapsel mit 2 der 3 Photosensibilisatoren, Photosan-3 und BPD-MA. Im Gegensatz dazu waren die bradytrophen Strukturen von Knorpel, Meniskus und Ligamenten weder makroskopisch noch mikroskopisch verändert. Die photodynamische Lasertherapie stellt ein neues Verfahren zur Behandlung der Synovitis dar. Ihre Vorteile sind Effektivität und maximale Selektivität bei gleichzeitig minimaler Invasivität. Damit bietet die photodynamische Therapie eine neue Perspektive für die chirurgische Behandlung chronisch-entzündlicher Gelenkerkrankungen.
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