Endoscopic Fluorescence Angiography with Indocyanine Green : A Preclinical Study in the Swine

OBJECTIVE: Microscopic indocyanine green (ICG) angiography is useful for identifying the completeness of aneurysm clipping and the preservation of parent arteries and small perforators. Neuroendoscopy is helpful for visualizing structures beyond the straight line of the microscopic view. We evaluated our prototype of endoscopic ICG fluorescence angiography in swine, which we developed in order to combine the merits of microscopic ICG angiography and endoscopy. METHODS: Our endoscopic ICG system consists of a camera, a light source, a display and software. This system can simultaneously display real-time visible and near infrared fluorescence imaging on the same monitor. A commercially available endoscope was used, which was 4 mm in diameter and had an angle of 30degrees. A male crossbred swine was used. RESULTS: Under general anesthesia, a small craniotomy was performed and the brain surface of the swine was exposed. ICG was injected via the ear vein with a bolus dose of 0.3 mg/kg. Visible and ICG fluorescence images of cortical vessels were simultaneously observed on the display monitor at high resolution. The real-time merging of the visible and fluorescent images corresponded well. CONCLUSION: Simultaneous visible color and ICG fluorescent imaging of the cortical vessels in the swine brain was satisfactory. Technical improvement and clinical implication are expected.

Collagen Synthesis and Expression of TGF-beta1 in Er:glass Fractional Laser Treated Hairless Mice / 대한피부과학회지

BACKGROUND: Non-ablative dermal remodeling and ablative skin resurfacing are currently well-established skin treatment modalities. Fractional laser was recently introduced as a new concept for laser skin rejuvenation, and is characterized by creation of a dense pattern of epidermal and dermal microthermal treatment zones (MTZs). However, the precise mechanisms of dermal remodeling by Er:glass fractional laser treatment are largely unknown. OBJECTIVE: The purpose of this study was to investigate the effect of 1,550 nm Er:glass fractional laser treatment on dermal collagen synthesis and expression of TGF-beta1, a potent cytokine involved in collagen synthesis. METHODS: We treated hairless mice with several power densities (5 W 5 mJ~20 W 20 mJ), and examined the tissue samples on days 1, 30, and 90 after treatment. We analyzed the penetrating depth of laser treatment by determining dermal response through assessment of type I collagen synthesis and TGF-beta1 expression by H&E, Masson-trichrome staining, western blot analysis and immunohistochemistry staining. RESULTS: We observed, through H&E staining, that increasing the pulse energy of fractional laser treatment correlated with increasing depth of MTZ. Also, fractional laser treatment increased type 1 collagen synthesis on days 30 and 90, energy dependently. Immunohistochemical study showed that fractional laser treatment increased expression of type I collagen and TGF-beta1, energy dependently, with TGF-beta1 expression peaking on day 1. In addition, according to western blot analysis, expressions of TGF-beta1 and type I collagen were up-regulated in an energy- dependent manner. CONCLUSION: Er:glass fractional laser induced dermal remodeling by up-regulation of TGF-beta1 and type I collagen synthesis, and may be a promising modality for skin rejuvenation.