Lasers in surgery and medicine
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Randomized Controlled Trial
Effects of a preceding fractional carbon dioxide laser on the outcome of combined local narrowband ultraviolet B and topical steroids in patients with vitiligo in difficult-to-treat areas.
Conventional treatment of vitiligo on hands and feet often produces an unsatisfactory result. Various ablative treatment methods were tried with favorable results in facial, neck, and truncal areas. The aim of this study is to evaluate the efficacy and safety of combined fractional CO2 laser, narrowband UVB (NB-UVB) phototherapy, and topical clobetasol propionate in managing stable vitiligo in difficult-to-treat areas. ⋯ This study demonstrates that adding fractional CO2 laser treatment to NB-UVB phototherapy and topical steroids improves the repigmentation rate of vitiliginous lesions on hands in some patients. This technique may be offered to vitiligo patients who are unresponsive to other treatments.
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Comparative Study
Ablation of porcine ligamentum flavum with Ho:YAG, q-switched Ho:YAG, and quadrupled Nd:YAG lasers.
Ligamentum flavum (LF) is a tough, rubbery connective tissue providing a portion of the ligamentous stability to the spinal column, and in its hypertrophied state forms a significant compressive pathology in degenerative spinal stenosis. The interaction of lasers and this biological tissue have not been thoroughly studied. Technological advances improving endoscopic surgical access to the spinal canal makes selective removal of LF using small, flexible tools such as laser-coupled fiber optics increasingly attractive for treatment of debilitating spinal stenosis. Testing was performed to assess the effect of Ho:YAG, Q-switched Ho:YAG, and frequency quadrupled Nd:YAG lasers on samples of porcine LF. The objective was to evaluate the suitability of these lasers for surgical removal of LF. ⋯ The Ho:YAG, Q-Switched Ho:YAG, and frequency quadrupled Nd:YAG lasers were shown to remove ligamentum flavum (LF). A single pulse of the Ho:YAG laser was shown to cause tearing of the tissue and a large zone of necrosis surrounding the laser-hole. Multiple pulses of the Ho:YAG and Q-Switched Ho:YAG lasers caused charring around the rim of the laser-hole, though the extent of charring was more extensive with the Ho:YAG laser. Charring caused by the Ho:YAG laser was shown to be mitigated by continuously flushing the affected LF with saline during irradiation. The Nd:YAG laser was shown to ablate LF with no gross visible indication of thermal damage to surrounding LF.
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Near-infrared Spectroscopy (NIRS) is a broadly utilized technology with many emerging applications including clinical diagnostics, sports medicine, and functional neuroimaging, to name a few. For functional brain imaging NIR light is delivered at multiple wavelengths through the scalp and skull to the brain to enable spatial oximetry measurements. Dynamic changes in brain oxygenation are highly correlated with neural stimulation, activation, and function. ⋯ Existing NIRS instrumentation has been further integrated within a custom helmet device to provide a uniform force distribution across the NIRS sensor array. These results showed a gradual decrease in time-averaged standard deviation among channels with an increase in applied pressure. Through these experiments, and the development of the MOC-NIRS helmet device, MOC appears to provide enhancement of NIRS technology beyond its current limitations.
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High-grade gliomas represent a widely heterogeneous group of tumors, the most frequent of which is glioblastoma multiforme. Its annual incidence has risen over the last decades, particularly amongst elderly people. The actual standards of care allow for a 15-month median survival rate for WHO grade IV gliomas. ⋯ PpIX is fluorescent under blue light exposure. Recent studies reported a significant increase in complete resections using FGR, which were associated with prolonged progression free survival, fewer reinterventions, and delayed neurological deterioration. Here, we depict the principles of this surgical technique, its actual outcomes, and future developments.
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Magnetic-Resonance Guided Laser-Induced Thermal Therapy (MRgLITT) is a minimally-invasive ablation procedure for treating intracranial pathology using laser energy delivered through a fiber-optic. Saline irrigation is used to cool the fiber-optic, but factors affecting irrigation efficacy are not well studied, and quantitative information regarding irrigation speed and volume during MRgLITT procedures have not been reported. Here, we aimed to characterize variables affecting irrigation efficacy in MRgLITT. ⋯ Flow rate through the cooling catheter in MRgLITT follows a non-linear pattern with increasing peristaltic pump speed. This rate is subject to significant changes when the bone anchor is tightened more than two quarter-turns. These findings serve as a foundation for future studies aimed at understanding the effect of irrigation speeds in achieving optimal ablation volumes.