Background and aims: We devised a technique to treat peripheral arterial disease (PAD) with laser, i.e. percutaneous transluminal laser angioplasty (PTLA). Considerable good results were obtained with PTLA, but it is apparently considered obsolete as a technique to treat occlusive arterial disease of peripheral arteries, perhaps because of the development and improvement of stents and the ease of their use compared to the somewhat intricate technique required for PTLA. Although the author admits the usefulness of stents, they are foreign to a human body. PTLA does not use a foreign body and contributes to the regeneration of the body’s own artery. The aim of this article is to elucidate the beneficial effects of laser procedures in the treatment of PAD and to show the resulting good long-term patency, and to propose PTLA as an option to treat PAD. Some basic experiments and their results useful for PTLA will be introduced. Materials and Methods: Ninety cases with occlusive peripheral arterial diseases were treated with PTLA during the period of March 1985 to March 1991. Our method of PTLA consists of occlusion of the proximal artery by a dilated balloon of a percutaneously introduced balloon catheter, and flushing with normal saline during irradiation by Nd:YAG laser. We used a ceramic tip attached to a laser catheter most of the time and a bare laser fiber under angioscopy or a bare laser fiber itself to treat smaller arteries in the legs. Results: The initial success rate was 90%. The patency rates of PAD at 6 years are 91.4% (iliac artery) and 85.8% (femoropopliteal artery), and the patency rate of leg artery lesions is 100% at 5 years. Some clinical cases with long-term patency (6 and 30 years) will be introduced. Some fundamental experiments useful to the application of laser to atheroma or thrombi will be introduced. Conclusion: PTLA could be a useful option to treat occlusive PAD, because it can produce longterm patency of natural arteries, provided a proper lesion was selected.
Background and aims: The selective removal of tattoos and benign cutaneous pigmented lesions with laser energy evolved rapidly with the development of the nanosecond-domain Q-switched laser (ns-laser). Recently, however, a series of picosecond-domain lasers (ps-lasers) with pulsewidths less than 1 ns has become commercially available, enabling more efficient and faster removal of pigmented lesions in the field of dermatologic laser surgery. Rationale behind the ps-laser: The efficacy of the ns-laser depended on the theory of selective photothermolysis, whereby an extremely short pulse width was delivered less than the thermal relaxation time (TRT) of a target. At sub-ns pulsewidths, i.e. in the ps-domain, this efficacy is dramatically extended through defeating the stress relaxation time (SRT) of a target allowing for even more effective pigment destruction with even less damage to the surrounding normal tissue. This will be discussed in detail. Clinical applications: The ps-laser has been reported as achieving tattoo removal in fewer sessions than the ns-laser, with less in the way of unwanted side effects. Tattoos recalcitrant to nslaser treatment have responded well to the ps-laser, and although true ‘color blindness’ is not yet completely achieved with the ps-domain pulses currently available, multicolored tattoos have also responded very favorably. The ability to limit damage precisely to the pigment target gives greater efficacy in treatment of epidermal lesions with less induction of post-inflammatory hyperpigmentation in the PIH-susceptible Asian skin, and dermal melanocytosis also respond very well to ps-laser treatment. Illustrative clinical examples from the author’s experience are given. Conclusion: Current ps-lasers could be a revolutionary advance for laser tattoo removal but may be less effective for some specific aesthetic indications such as melasma and other cosmetic procedures. Manufacturers must make an effort to reduce the current comparatively long ps-domain pulsewidths to deliver a ‘true’ ps-domain laser, with more basic studies also being required to allow expansion of the safe and effective use of the ps-laser outside of tattoo removal.
Background and aims: Endovenous laser ablation (EVLA) has been well-reported as a minimally invasive method to deal with varices of the lower extremities. The lasers used fall into two categories: pigment, i.e., hemoglobin-specific lasers in the visible and near-infrared (near-IR) wavebands and longer wavelength mid-infrared lasers where the chromophore is water. The fiber used to deliver the laser energy is also important, and not enough attention has been paid to this element of EVLA. The present study was therefore designed to compare EVLA delivered through two specific fiber types coupled with a near-IR laser wavelength where water was the major chromophore. Materials and Methods: A laser diode system at the wavelength of 1470 nm was used as the laser energy source near a peak in the water absorption spectrum. Laser energy was delivered with two specific types of optical fiber, a Radial™ fiber and a Radial 2ring ™ fiber (CeramOptec, Germany), and EVLA was evaluated using a computer simulation model taking light transport into account based on the Monte Carlo method and temperature distribution with the heat conduction equation Results and conclusions: TIt was confirmed from both the simulation model and a previously published ex vivo experiment that carbonization and sticking during EVLA caused by excess temperature rise can be minimized by using the Radial 2ring fiber compared with the Radial fiber, coupled with the 1470 nm wavelength. In the future, lasers with different wavelengths or optical fibers with differing irradiation modes may appear as candidate systems for EVLA. It is important to evaluate safety and efficacy carefully using the methods in the present study before moving to in vivo indications in human subjects.
The aim of this trial was to assess the efficacy of polarized polychromatic noncoherent light (Bioptron light) in the treatment of Carpal Tunnel Syndrome (CTS) in pregnancy. An uncontrolled experimental study was conducted in pregnant patients with CTS who visited our clinic from January 2006 to January 2010. Bioptron light (480-3400 nm; 95% polarization; 40 mW/cm²; and 2.4 J/cm²) was administered perpendicular to the carpal tunnel area. The irradiation time for each session was 6 min at an operating distance of 5-10 cm from the carpal tunnel area, twice each day, five days per week for 2 weeks. Pain and paraesthesia using a visual analogue scale (VAS) and finger pinch strength were evaluated at the end of treatment (week 2) and 1-month (week 6) after the end of treatment. The Student’s t test was used and p values ‹ 0.05 were accepted as statistically significant. 46 patients participated in the study. The mean age of subjects was 27.6 years (range 22-37). The patient population had a mean duration of CTS of 2.3 months (range 1-4). All patients were in the third trimester. Pain and paraesthesia decreased at the end of treatment and at the 1-month follow-up, whereas the finger pinch strength increased at the end of treatment and at the 1-month follow-up. In conclusion, the results of the present study suggest that Bioptron light is a reliable, safe, and effective treatment option in pregnant patients with CTS. Controlled clinical trials are needed to establish the absolute and relative effectiveness of this intervention.
Objectives: This study aimed to assess the microshear bond strength of a repairing self-adhesive flowable composite to ceramic after mechanical, chemical and laser treatment of the ceramic surface. Materials and Methods: Forty zirconia and forty feldspathic ceramic blocks measuring 8 x 8 x 2 mm were fabricated. Feldspathic blocks were divided into four groups of control (1), laser (2780 nm) (2), sandblasting + hydrofluoric (HF) acid + silane (3) and laser (2780 nm) + HF acid + silane (4). Zirconia blocks were also divided into four groups of control (1), laser (2780 nm) (2), sandblasting + Z-Prime Plus (3) and laser (2780 nm) + Z-Prime Plus (4). Vertise Flow composite was bonded to treated ceramic surfaces as a repairing material, then the samples were subjected to 1000 thermal cycles. Repair bond strength was measured by Instron machine and data were analyzed using one-way ANOVA and post hoc test (P < 0.05). Results: Maximum and minimum bond strength values were observed in zirconia-control (22.57 ± 4.76 MPa) and feldspathic-control (8.65 ± 6.41 MPa) groups, respectively. There was no significant differences between subgroups within the zirconia or feldspathic groups (P > 0.05), however the bond strength of zirconia subgroups was significantly higher than that of feldspathic subgroups. Conclusion: Vertise Flow provides relatively good bond strength to ceramic even with no surface treatment.
Background and Aim: Venous malformations (VMs) are slow-flow vascular anomalies composed of ectatic venous channels. Its management with Er,Cr:YSGG laser has been proven effective. In the present case a teenage patient reported with a bluish lesion, soft inconsistency on the dorsal aspect of tongue. The lesion was removed with Er, Cr: YSGG laser (2780 nm) with minimal anaesthetic infiltration Results: Patient reported no postoperative pain. Clinical follow up after three months showed excellent results and uneventful healing. Conclusions: Er,Cr:YSGG laser showed high clinical safety. Its advantages resulted in excellent healing of lesion and better acceptance by patient.
Background and Aims: The aim of this ex vivo study was to demonstrate the performances of 1070 nm fiber lasers for the ablation of oral tissues through the evaluation of the histological modifications made by a blind pathologist and the measurement of the thermal elevation during laser irradiation by a sensor based on a fiber Bragg grating. Materials and Methods: The source used was a pulsed fiber laser emitting at 1070 nm, with 20 W maximum average output power and 100 ns fixed pulse duration. Different tests were performed by changing the laser parameters, particularly the peak power of the pulses and the repetition rate. Results: The tissue of the measurements demonstrated that the best properties in term of cutting capability and, at the same time, the lower thermal damages to the tissues can be obtained with a peak power of 3 kW, a repetition rate of 50 kHz and a speed of 5 mm/s. Conclusions: This ex vivo study showed that 1070 nm fiber lasers can be very useful in oral surgery, since they provide a reduced thermal elevation in the irradiated tissues, thus consequently respecting their biological structures. Moreover, this work demonstrates that FBG sensors, based on the optical fiber technology as the laser source considered for the tests, may be good instruments to record thermal elevation when applied to the ex vivo studies on animal models.