We developed the second harmonic of diode pumped solid state Nd:YAG pulsed laser (λ=532nm) as a new treatment for a acute cerebral embolism. In the present study, we examined the selective thrombus removal effect of the pulsed laser irradiation using a rat thrombosis model. The laser irradiation significantly reduced blood clots in comparison to the non-irradiated group (N = 6). In addition, dynamic analysis using in vitro phantom models and a high speed imaging camera, showed that the clot was disrupted by a bubble generated by pulsed laser irradiation.

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The present investigation was carried out to study the anti-rheumatic activities of free electron laser (FEL) irradiation on hind paw inflammation in rat collagen-induced arthritis (CIA) models. CIA was induced in 6-week-old female Lewis rats by immunization with intradermal injections of bovine type II collagen emulsified in complete Freund's adjuvant. The animals were subdivided into the following groups: control group, CIA group and FEL irradiated CIA group (FEL group). FEL group was irradiated at 1,750 nm with a dose of 5 J/cm² for 500s and 1,000s in knee joints six times a week for 2 weeks. The hind paw swelling was assessed by measuring the thickness of the two hind paws with a digital caliper. The lateral femur bone and hind paw resorption were evaluated by Micro-CT. The serum levels of the inflammatory cytokines and arthritic factor MMP-3 were determined by ELISA. In FEL-500 and FEL-1000 groups at 2 weeks after arthritis induction, swelling inhibition index was 23.3±3.7% and 31.0±5.8 %, respectively. FEL irradiation decreased the bone erosion and reduced the bone resorption in CIA rats. IL-1β, IL-6 and MMP-3 serum levels were significantly lower in FEL groups.

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Bladder calculi account for 5% of urinary calculi and usually occur because of bladder outlet obstruction, neurogenic bladder, urinary tract infection, or foreign bodies. In adults, bladder calculi can be treated endoscopiccally by mechanical cystolithotripsy, ultrasound and electrohydraulic lithotripsy, pneumatic lithotripsy, and Holmium:yttrium-aluminum garnet (Ho:YAG) laser. Recent studies have demonstrated the advantages the Ho:YAG laser lithotripsy for the treatment of bladder calculi, in comparison with other modalities. We assessed the safety and effectiveness of transurethral Ho:YAG laser cystolithotripsy for the treatment of bladder calculi. From January 2007 to December 2009, transurethral cystolithotripsy with Ho:YAG laser was done for 13 patients. All the patients became stone-free at one session. No major intra and post-operative complication occurred. It is concluded that transurethral Ho:YAG laser cystolithotripsy is safe and effective in patient with bladder stone.

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Holmium laser enucleation of the prostate (HoLEP) allows a safe and effective treatment for bladder outlet obstruction due to benign prostatic hyperplasia (BPH). Although total energy dissipated for each procedure can be recorded, there is no published data evaluating for total energy used consumption. . We retrospectively reviewed data from 55 consecutive patients treated by HoLEP which were performed by a single Urologist from January 2010 to May 2010.
We focused on following items; enulceation time(min), enucleated volume(g), total energy used output on HoLEP(kJ). Correlation between the encleation volume/ enucleation time (g/min) cannot be found, however, procedure time gets longer as energy dissipation per enucleated gram become larger. We found out that the total energy used/ encleation time (kJ/min) was stable regardless of the case. In addition to that, the data revealed that for BPH volume less than 30g, energy dissipated per gram enuleated increased greatly. This result indicates that enucleation efficiency of smaller glands is lower than that of larger glands.

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Treatment of cedar pollinosis with laser equipments is very effective. Much attention to the cedar pollinosis treatment is being paid from economic perspectives, but there have not been any reports which analyze the cost effect in Japan. To assess the economical effect the authors analyze the costs of three typical treatment protocols for cedar pollinosis: laser treatment, anti-histamine prescription and desensitization immunotherapy. The authors calculate the direct costs and the indirect cost and analyze the economical effects. In consequence the authors suggest the laser treatment is better in the point of economic effect, compared to the two other treatment protocols.

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Malignant glioma is growing up in the normal brain tissues. It is invasive. Surgical removal of the tumor is one of the effective treatment for the malignant gliomas. However, it is very difficult to remove extensively, because lethal neurological deficit occurs after extensive removal including normal brain tissues.
Therapeutic method that only glioma can be treated selectively is requires for the treatment of the malignant glioma.
Photodynamic Therapy (PDT) is one of the most interesting and local treatment at the present time. PDT is depending upon the light activation of a photosensitizer that is selectively taken up or retained in the malignant glioma cells, and also PDT is one of the therapeutic method that malignant gliomas can be treated selectively.
We performed two series of PDT for malignant gliomas. One is stereotactic interstitial PDT of malignant glioma that deeply seated in the brain and the other one is PDT following maximum surgical removal using PDD for malignanat glioma that is in the eloquent area in the brain or spinal cord.
‹ stereotactic interstitial PDT ›
26 malignant brain tumors that were seated deeply in the brain, were treated with stereotactic intratumoral PDT using Photofrin 2mg/kg and 630nm wave length laser. Optical fiber was inserted into predetermined photoilluminating points of tumor by stereotactic methods, and photoillumination with power output 200 mW was applied for 15 minutes . The photoillumination was repeated several times depending on tumor volume.
All tumors clearly showed a reduction in tumor volume 4 weeks after stereotactic PDT. A complete responses (CR) was obtained in 19 tumors(63%) , PR was in 8 tumors(27%), NC was in 3 tumors(10 %). All tumors which are less than 5.0 ml in volume showed complete disappearance on enhanced MRI.
‹PDT following PDD›
13 malignant gliomas that were seated at the eloquent area in the brain or spinal cord, were treated with PDT using Photofrin after maximum safe surgical removal using ALA. PDT after maximum removal using PDD did not cause any serious complications.
Although long-term survival cases of glioblastoma were confirmed.
These studies indicated that PDT is showing highly selective, safe, improved good quality survival, and delayed tumor relapse.
It will be necessary to randomized control study with larger number of cases in the future.

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Photodynamic therapy (PDT) is one of the therapeutic methodology which induce selective cell damage caused by photochemical reaction with laser irradiation to photosensitizer. PDT using talaporfin sodium is a new adjuvant therapeutic strategy for glioblastoma. Talaporfin sodium is known as photosensitized mainly for PDT but not for fluorescence diagnoses. We applied quantitative measurement technique of 5-ALA to talaporfin. In this study, we evaluated the feasibility of talaporfin sodium as photosensitized for fluorescence diagnoses.

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The usefulness of photodynamic diagnosis (PDD) using 5-aminolevulinic acid (5-ALA) in malignant glioma surgery has been proved by some reports, which indicated the effect of 5-ALA PDD on improving tumor resection ratio and prolongation of survival time. However, 5-ALA PDD has two unsolved problems.
One is subjective judgments of fluorescence intensity. The evaluation of fluorescence intensity by naked eye is still subjective and easy to be influenced by observation conditions. This problem is serious for diagnosis. In this paper, we review the all methods for fluorescence quantification and introduce our new method for quantification of fluorescence using spectroradiometer.
Another one is that the mechanism of porphyrin accumulation in tumor tissue has not been well established. In this paper, we review the proposal mechanisms of porphyrin accumulation in tumor cells. Additionally, we introduce our new hypothesis that coproporphyrinogen oxidase may be a key enzyme for porphyrin accumulation for malignant tumor.

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We received the manufacturing and marketing approval of an endovenous laser ablation therapeutic system “ELVeS laser” on June 2011. It took us five and a half years to obtain the approval. In this paper, varicose vein, the overview of ELVeS laser, the application for the approval, and a risk and a device gap in medical device applications are described. Also, the questions “Why did it take such a long time” and “How was the process” are reviewed.

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On June 22, 2010, the first femtosecond laser, InstaLase FS Laser (FS60), was approved in Japan. FS60 was developed by IntraLase Corp. (current Abbott Medical Optics, Inc.) in the U.S. The indication of FS60 is LASIK flap creation and keratoplasty, and was approved by the FDA in 2006. The principle is “Photodisruption”, in which a near-infrared laser continuously creates voids in corneal stroma.
Although FS60 was a brand new medical device in Japan, we received approval without conducting clinical trials in Japan. Instead, we introduced the clinical evaluation approach in the PMDA' consultation meeting.
On February 8, 2011, the second femtosecond laser, iFS, was also approved. In addition, iFS upgrading was approved in June which allowed us to upgrade existing FS60 units to iFS onsite. Although femtosecond laser keratoplasty is promising better clinical outcome, physicians have to overcome their hurdles such as purchase expense of the equipment and cost of essential maintenance. Reimbursement fee must include these costs.
For whatever reason, FS60 is an example of device lag. Nowadays, device lag is the most urgent issue that should be solved. Consequently, I would like to share the recent survey results of device lag and the attempt at speeding the review.

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On April 2010, Vbeam®, flashlamp pumped long-pulsed dye laser system (Candela Co., Wayland, MA, USA), was approved for the use of the treatment of cutaneous vascular lesions (capillary malformations, infantile hemangiomas and telangiectasias) in Japan. This system can emit the 595 nm laser beam, and the pulse duration is adjustable from 0.45 msec to 40 msec changing the sub-pulse sequences. And cryogen spray cooling system is equipped on the output-handpiece, and cryogen spurts before laser irradiation can protect the epidermal heat damage. The longer wavelength allows the deeper penetration into the skin and the longer pulse duration with high fluence is considered to be optimal for damaging lager diameter microvessels with less adverse effects.
We report the characteristics of this new approved laser device from the point of mechanical specifications in this article.

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