Survival of Chondrocytes in Rabbit Septal Cartilage After Electromechanical Reshaping

Electromechanical reshaping (EMR) has been recently described as an alternative method for reshaping facial cartilage without the need for incisions or sutures. This study focuses on determining the short- and long-term viability of chondrocytes following EMR in cartilage grafts maintained in tissue culture. Flat rabbit nasal septal cartilage specimens were bent into semi-cylindrical shapes by an aluminum jig while a constant electric voltage was applied across the concave and convex surfaces. After EMR, specimens were maintained in culture media for 64 days. Over this time period, specimens were serially biopsied and then stained with a fluorescent live–dead assay system and imaged using laser scanning confocal microscopy. In addition, the fraction of viable chondrocytes was measured, correlated with voltage, voltage application time, electric field configuration, and examined serially. The fraction of viable chondrocytes decreased with voltage and application time. High local electric field intensity and proximity to the positive electrode also focally reduced chondrocyte viability. The density of viable chondrocytes decreased over time and reached a steady state after 2–4 weeks. Viable cells were concentrated within the central region of the specimen. Approximately 20% of original chondrocytes remained viable after reshaping with optimal voltage and application time parameters and compared favorably with conventional surgical shape change techniques such as morselization

Cartilage reshaping: An overview of the state of the art

The laser irradiation of cartilage results in a plastic deformation of the tissue allowing for the creation of new stable shapes. During photothermal stimulation, mechanically deformed cartilage undergoes a temperature dependent phase transition, which results in accelerated stress relaxation of the tissue matrix. Cartilage specimens thus reshaped can be used to recreate the underlying framework of structures in the head and neck. Optimization of this process has required an understanding of the biophysical processes accompanying reshaping and also determination of the laser dosimetry parameters, which maintain graft viability. Extensive in vitro, ex-vivo, and in vivo animal investigations, as well as human trials, have been conducted. This technology is now in use to correct septal deviations in an office-based setting. While the emphasis of clinical investigation has focused on septoplasty procedures, laser mediated cartilage reshaping may have application in surgical procedures involving the trachea, laryngeal framework, external ear, and nasal tip. Future directions for research and device design are discussed

Cartilage reshaping: An overview of the state of the art

The laser irradiation of cartilage results in a plastic deformation of the tissue allowing for the creation of new stable shapes. During photothermal stimulation, mechanically deformed cartilage undergoes a temperature dependent phase transition, which results in accelerated stress relaxation of the tissue matrix. Cartilage specimens thus reshaped can be used to recreate the underlying framework of structures in the head and neck. Optimization of this process has required an understanding of the biophysical processes accompanying reshaping and also determination of the laser dosimetry parameters, which maintain graft viability. Extensive in vitro, ex-vivo, and in vivo animal investigations, as well as human trials, have been conducted. This technology is now in use to correct septal deviations in an office-based setting. While the emphasis of clinical investigation has focused on septoplasty procedures, laser mediated cartilage reshaping may have application in surgical procedures involving the trachea, laryngeal framework, external ear, and nasal tip. Future directions for research and device design are discussed

Cartilage Reshaping

In this chapter, we introduce the working theory of cartilage reshaping and highlight landmark papers in the development and refinement of this technique. We discuss the tissue and mechanical properties of cartilage and define how optical techniques may be utilized to manipulate these properties. The goal of cartilage reshaping is to ultimately reduce the need for more invasive traditional approaches with scalpel and suture, in favor of much less invasive techniques. Therefore, we discuss the challenges associated with its development and delineate its translation toward clinical applications

Laser/Light Applications in Otolaryngology

Lasers have been ubiquitous in otolaryngology since Jako and Strong first introduced the CO2 laser in 1970. Since that time lasers have traditionally been used like a scalpel, able to cut and cauterize precisely. More recently, the role of lasers has been expanded in otolaryngology depending on the specific laser wavelength and dosimetry parameters. Not only can lasers be utilized to extirpate cancer, but also used to recover hearing, improve the airway, treat epistaxis, and even break up salivary stones for easy removal. The individual characteristics of the laser are important for the specific application. However, the otolaryngologist often works in areas that are either difficult to access using classic methods or require extreme precision, and the mechanism and method for delivering the laser energy is often equally important. In this chapter, we describe the many ways lasers are used in otolaryngology treat both benign conditions to life-threatening diseases. New and innovative applications are also discussed