Conventional therapy-resistant chronic ulcers have been treated recently with low energy lasers or light emitting diodes in the visible and near IR region. In the present work, we studied ulcer healing using broadband (400-800 nm) visible light. Twenty patients suffering from diabetic and venous ulcers were irradiated with broadband (400-800 nm, 40 mW/cm2) visible light. Each ulcer was irradiated for 5 minutes three times a day. Success was defined as the complete healing of the ulcer. A complete cure was observed in 70% of the patients. The duration of the therapy was 8-12 weeks. The new broadband visible light source seems to have a strong effect on the complete healing of ulcers.
Photodynamic therapy (PDT) is based on the theoretical principle: the specific low level laser light irradiation activates a photosensitizer which is selectively concentrated in rapidly proliferating tissues including malignant tumor cells, resulting in selective necrosis by the intracellular singlet oxygen from photochemical reaction. PDT using Photofrin® (porfimer sodium) with excimer-dye laser (EDL) was approved in Japan. Its indication for GI cancers was limited to superficial esophageal and early gastric cancer not indicated for other curative treatments. Meanwhile, endoscopic mucosal resection (EMR) is considered the first choice of treatment for intra-mucosal GI cancers. Thus PDT has been considered as one of the alternative treatments for GI cancers including recurrent cancer; however, its efficacy was relatively limited. Therefore, we have designed a new therapy called "Modified PDT". The major points of Modified PDT are as follows. 1. Irradiation of EDL is applied to the lesion not only 48 but also 72 hours after Photofrin® injection. 2. When the cancer is polypoid type, partial resection of the cancer is performed before irradiation. 3. Before the second irradiation, necrotic tissue covering the surface of the lesion is removed. Modified PDT was carried out on 20 patients (mean age 73 years). Complete response was achieved in 4 of 6 (66.7%) of superficial esophageal cancers, 9 of 10 (90%) of early gastric cancers, 1 of 3 (33.3%) of advanced gastric cancers and 1 rectal cancer. No serious complication occurred. Modified PDT may be considered an alternative therapy for GI cancers not indicated for EMR or surgery.
In Japan, nearly 15 to 20 % of the population suffers from allergic rhinitis during the spring season. Conventional treatment with oral anti-histamines has side-effects such as drowsiness and dryness of the throat and is not acceptable for some patients. Laser treatment usually uses the carbon dioxide (CO2) laser to charr the mucosal lining of the inferior turbinate in order to prevent onset of symptoms. This treatment has a downtime of roughly one month. Complications such as pain and hemorrhage sometimes require hospital admission. We have been using a flashlamp pumped Nd:YAG laser since 1993 with more favorable results both in efficacy and efficiency of treatment with less patient discomfort. A single treatment session takes around 2 to 3 minutes for both sides compared to 20 to 40 minutes with the CO2 laser and the downtime, which consists of rhinorhea, is much shorter lasting only 2,3 days to up to one week. Treatment using the flashlamp pumped Nd:YAG laser is very reliable but improvement may be achieved using a diode laser pumped Nd:YAG laser where theoretically the homogeneity of the incident laser beam will increase. We report our experience using the hardware developed by Fibertech Co. on 40 patients as a preliminary report with further reports with larger series of patients ensuing. We also compare this new laser system with the conventional YAG laser and describe the advantage of the diode laser pumped Nd:YAG laser in the treatment of allergic rhinitis, especially in an office practice setting of ENT doctors.
The carbon dioxide laser (CO2 laser) was one of the first 4 major lasers to be developed, and is now successfully employed for surgical procedures not only in the fields of plastic and general surgery field, but also in many other specialities, including dermatology, gynecology and otorhinolaryngology. In dermatosurgery, CO2 laser resurfacing for rejuvenating photoaged skin remains the gold standard. The CO2 laser produces a beam of mid-infrared energy at a primary band of 10,600 nanometers (nm) or 10.6 ˜ μm, at which wavelength the laser beam is very highly absorbed by water. Since human tissue comprises between 75% to 90% water, it follows that the CO2 laser beam can play many important roles in the surgical field, from cutting, through ablation to tissue welding and photobiomodulation. Its basic action in tissue is photothermal, almost instantaneously vaporizing target tissue (at appropriate power densities) by raising temperatures to well over 100°C. Because of the selective absorption in water, however, minimal damage is caused to adjacent tissue. The CO2 laser offers the following benefits: reduction in trauma; almost bloodless surgery compared with the conventional scalpel; improved therapeutic results; reduced risk of infection; less scarring; precisely controlled surgery which limits injury to normal skin; and safe and effective recovery for many surgical conditions, often faster than conventional approaches and therefore achieving shorter hospital stays. From his experience with the CO2 laser encompassing some four decades, the author presents herein his accumulated knowledge of all types of CO2 laser surgery, even in patients with any of the coagulopathies. The CO2 laser is thus well- and widely-adapted for current, and future, clinical indications, offering a versatile and practical alternative to traditional scalpel surgery in many medical fields.
The mW level low power lasers, GaAlAs diode lasers, He-Ne laser and argon dye laser have been applied to the author’s clinical and experimental studies. As the results, the following interesting effects have been newly found in addition to previously recognized effects such as anti inflammation effect, wound healing activation effect, analgesic effect: 1) The unique effects in the diode laser: (1) Depigmentation effect on melanous nevi of a mucosa,(2) Therapeutic effect for trismus in TMJ troubles and (3) Improvement the salivation function in its restricted disease of Sjogren’s syndrome. 2) The unique effect in He-Ne laser:Therapeutic effect of the vasculargenous red colored lesions. 3) Common effect to the diode laser and He-Ne laser:Bone repaire activation effect. 4) Effect of argon dye laser:Reactive secondary dentin formation effect under the premedication of HpD. The effect under 1)∼3) have been successfully applied in the author’s clinic