Viability of human septal cartilage after 1.45 µm diode laser irradiation

Choi, Ick-Soo; Chae, Yongseok; Zemek, Allison; Protsenko, Dmitriy E.; Wong, Brian J. F.

doi:10.1002/lsm.20663

Cited by 21 publications

(30 citation statements)

References 34 publications

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“…18,19,21-23 To assess the viability of chon-drocytes, specimens were stained with the fluorophores calcein acetomethoxy and ethidium homodimer 1 and were imaged with a confocal microscope (Meta 510; Carl Zeiss LSM). Digital images were recorded and analyzed.…”

Section: Methodsmentioning

confidence: 99%

In Vivo Needle-Based Electromechanical Reshaping of Pinnae

Yau

Manuel

Hussain

et al. 2014

JAMA Facial Plast Surg

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IMPORTANCE Electromechanical reshaping (EMR) is a low-cost, needle-based, and simple means to shape cartilage tissue without the use of scalpels, sutures, or heat that can potentially be used in an outpatient setting to perform otoplasty.OBJECTIVES To demonstrate that EMR can alter the shape of intact pinnae in an in vivo animal model and to show that the amount of shape change and the limited cell injury are proportional to the dosimetry. DESIGN, SETTING, AND SPECIMENSIn an academic research setting, intact ears of 18 New Zealand white rabbits underwent EMR using 6 different dosimetry parameters (4 V for 5 minutes, 4 V for 4 minutes, 5 V for 3 minutes, 5 V for 4 minutes, 6 V for 2 minutes, and 6 V for 3 minutes). A custom acrylic jig with 2 rows of platinum needle electrodes was used to bend ears at the middle of the pinna and to perform EMR. Treatment was repeated twice per pinna, in proximal and distal locations. Control pinnae were not subjected to current application when being bent and perforated within the jig. Pinnae were splinted for 3 months along the region of the bend using soft silicon sheeting and a cotton bolster. MAIN OUTCOMES AND MEASURESThe ears were harvested the day after splints were removed and before euthanasia. Photographs of ears were obtained, and bend angles were measured. Tissue was sectioned for histologic examination and confocal microscopy to assess changes to microscopic structure and cellular viability.RESULTS Treated pinnae were bent more and retained shape better than control pinnae. The mean (SD) bend angles in the 7 dosimetry groups were 55°(35°) for the control, 60°(15°) for 4 V for 4 minutes, 118°(15°) for 4 V for 5 minutes, 88°(26°) for 5 V for 3 minutes, 80°(17°) for 5 V for 4 minutes, 117°(21°) for 6 V for 2 minutes, and 125°(18°) for 6 V for 3 minutes. Shape change was proportional to electrical charge transfer, which increased with voltage and application time. Hematoxylin-eosin staining of the pinnae identified localized areas of cell injury and fibrosis in the cartilage and in the surrounding soft tissue where the needle electrodes were inserted. This circumferential zone of injury (range, 1.5-2.5 mm) corresponded to dead cells on cell viability assay, and the diameter of this region increased with total electrical charge transfer to a maximum of 2.5 mm at 6 V for 3 minutes.CONCLUSIONS AND RELEVANCE Electromechanical reshaping produced shape change in intact pinnae of rabbits in this expanded in vivo study. A short application of 4 to 6 V can achieve adequate reshaping of the pinnae. Tissue injury around the electrodes increases with the amount of total current transferred into the tissue and is modest in spatial distribution. This study is a critical step toward evaluation of EMR in clinical trials.LEVEL OF EVIDENCE NA.

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Section: Methodsmentioning

confidence: 99%

In Vivo Needle-Based Electromechanical Reshaping of Pinnae

Yau

Manuel

Hussain

et al. 2014

JAMA Facial Plast Surg

Self Cite

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“…Assessing chondrocyte viability using laser confocal microscopy and live-dead fluorescent assays is a well-established technique, 15,16 aiding the optimization of EMR dosimetry and geometry of electrode placement. Confocal microscopy identified some regions of tissue injury, which were spatially limited to the immediate vicinity around each needle electrode up to 1.2-mm away.…”

Section: Commentmentioning

confidence: 99%

In Vivo Electromechanical Reshaping of Ear Cartilage in a Rabbit Model

Oliaei

Manuel²,

Karam³

et al. 2013

JAMA Facial Plast Surg

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“…24,25,27–29 Confocal microscopy identified a sharply demarcated, hemispherically shaped region of nonviable cells at the laser target. After irradiation at 6 W for 2 seconds, the largest extent of nonviable cells was 0.8 mm deep with a 1.9-mm surface diameter (Figure 7A).…”

Section: Resultsmentioning

confidence: 99%

“…A cell viability assay (LIVE/DEAD; Molecular Probes, Eugene, Oregon) in conjunction with fluorescent confocal microscopy (Model LSM 510 META; Carl Zeiss, Jena, Germany) was performed on the cross-sectional slice by following the protocol described by Choi et al 25 In the resulting images, green fluorescence indicated live cells, whereas red fluorescence indicated dead cells with compromised cell membranes. The maximum area of thermal damage was determined by measuring the depth and surface diameter of the red fluorescing region for 3 samples per dosimetry setting.…”

Section: Methodsmentioning

confidence: 99%

Stabilization of Costal Cartilage Graft Warping Using Infrared Laser Irradiation in a Porcine Model

Foulad

Ghasri²,

Garg³

et al. 2010

Arch Facial Plast Surg

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Objective To develop a method to rapidly stabilize the shape change process in peripheral slices of costal cartilage by using infrared laser irradiation in a porcine model. Methods Forty peripheral porcine costal cartilage specimens (40×10×2 mm) were harvested. Thirty of these specimens were immediately irradiated with an Nd: YAG laser (λ=1.32 μm; spot size, 2-mm diameter) using 1 of 3 exposure treatments: 6W, 2 seconds, and 4 spots; 8 W, 3 seconds, and 4 spots; or 6 W, 2 seconds, and 8 spots. Ten control specimens were only immersed in 0.9% saline solution. Angle of curvature was measured from photographs taken at 0 minutes, immediately after irradiation, and at 30 minutes, 1 hour, 5 hours, and 24 hours. Infrared imaging was used to measure surface temperatures during irradiation. Cell viability after irradiation was determined using a live/dead assay in conjunction with fluorescent confocal microscopy. Results Compared with the untreated controls, the irradiated grafts underwent accelerated shape change within the first 30 minutes to reach a stable geometry. Thereafter, irradiated grafts underwent little or no shape change, whereas the control group exhibited significant change in curvature from 30 minutes to 24 hours (P<.001). The average peak irradiated spot temperatures ranged from 76°C to 82°C. Cell viability measurements at the laser spot sites demonstrated a hemispherically shaped region of dead cells with a depth of 0.8 to 1.2 mm and a surface diameter of 1.9 to 2.7 mm. Conclusions Laser irradiation of peripheral costal cartilage slices provides an effective method for rapidly stabilizing acute shape change by accelerating the warping process. The temperature elevations necessary to achieve this are spatially limited and well within the limits of tolerable tissue injury.

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Viability of human septal cartilage after 1.45 µm diode laser irradiation

Cited by 21 publications

References 34 publications

In Vivo Needle-Based Electromechanical Reshaping of Pinnae

In Vivo Needle-Based Electromechanical Reshaping of Pinnae

In Vivo Electromechanical Reshaping of Ear Cartilage in a Rabbit Model

Stabilization of Costal Cartilage Graft Warping Using Infrared Laser Irradiation in a Porcine Model

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