Stabilization of costal cartilage graft warping using infrared laser irradiation in a porcine model

Infrared Laser Effect on Healthy and Ossified Costal Cartilage: The Development of Stable Load-Bearing Autoimplants

BACKGROUND AND OBJECTIVE

The laser-induced stress relaxation provides new prospects to obtain stable long fragments of costal cartilage for autoimplantation avoiding the risk of spontaneous deformation and poor engraftment. However, the age-related alterations of cartilage may sufficiently influence its interaction with infrared (IR) laser radiation and disrupt the effectiveness and safety of the technique. The aim of the work is to study the influence of the structural quality of costal cartilage on its interaction with IR laser and efficiency of obtaining of curved implants for trachea surgery.

STUDY DESIGN/MATERIALS AND METHODS

Healthy costal cartilage was taken from pigs and human. Ossified costal cartilage was taken from humans of age 65 ± 7. The cartilage slices with a mean thickness of 3 mm were mechanically curved and processed to stress relaxation by laser irradiation with the wavelength 1.56 µm. The structure and mineral content were studied by X-ray microtomography and element analysis. The optical measurements included the study of the propagation of IR radiation, speckle interferometry, and IR radiometry.

RESULTS

The aged cartilage demonstrates a high level of heterogeneity in structure and properties and decreased water content. The presence of dense inclusions consisting of amorphous calcined volumes makes the tissue more fragile and less elastic. The IR radiation propagation intensity for aged cartilage is at least twice higher than that for healthy cartilage. The thermal-induced motion of scatterers in aged cartilage is slower. X-ray microtomography showed the cartilage-like and the bone-like structures within the ossified samples.

CONCLUSIONS

The main challenge for laser reshaping of aged cartilage is the presence of ossifications. However, the new stable curvature can be obtained with adjustment of laser power. To obtain the satisfying stable curvature of an implant the ossified volumes should be avoided The laser-induced stress-relaxation mechanism for aged cartilage can be particularly different from that of healthy tissue and the optimal laser regimes should be specified. Lasers Surg. Med. © 2020 Wiley Periodicals, Inc.

Toward tissue-engineering of nasal cartilages

Nasal cartilage pathologies are common; for example, up to 80% of people are afflicted by deviated nasal septum conditions. Because cartilage provides the supportive framework of the nose, afflicted patients suffer low quality of life. To correct pathologies, graft cartilage is often required. Grafts are currently sourced from the patient's septum, ear, or rib. However, their use yields donor site morbidity and is limited by tissue quantity and quality. Additionally, rhinoplasty revision rates exceed 15%, exacerbating the shortage of graft cartilage. Alternative grafts, such as irradiated allogeneic rib cartilage, are associated with complications. Tissue-engineered neocartilage holds promise to address the limitations of current grafts. The engineering design process may be used to create suitable graft tissues. This process begins by identifying the surgeon's needs. Second, nasal cartilages' properties must be understood to define engineering design criteria. Limited investigations have examined nasal cartilage properties; numerous additional studies need to be performed to examine topographical variations, for example. Third, tissue-engineering processes must be applied to achieve the engineering design criteria. Within the recent past, strategies have frequently utilized human septal chondrocytes. As autologous and allogeneic rib graft cartilage is used, its suitability as a cell source should also be examined. Fourth, quantitative verification of engineered neocartilage is critical to check for successful achievement of the engineering design criteria. Finally, following the FDA paradigm, engineered neocartilage must be orthotopically validated in animals. Together, these steps delineate a path to engineer functional nasal neocartilages that may, ultimately, be used to treat human patients. STATEMENT OF SIGNIFICANCE: Nasal cartilage pathologies are common and lead to greatly diminished quality of life. The ability to correct pathologies is limited by cartilage graft quality and quantity, as well as donor site morbidity and surgical complications, such as infection and resorption. Despite the significance of nasal cartilage pathologies and high rhinoplasty revision rates (15%), little characterization and tissue-engineering work has been performed compared to other cartilages, such as articular cartilage. Furthermore, most work is published in clinical journals, with little in biomedical engineering. Therefore, this review discusses what nasal cartilage properties are known, summarizes the current state of nasal cartilage tissue-engineering, and makes recommendations via the engineering design process toward engineering functional nasal neocartilage to address current limitations.

Measurement of Warping Angle in Human Rib Graft: An Experimental Study

BACKGROUND

The purpose of this study was to determine the warping angle of the costal cartilage in vivo.

METHODS

A nasal framework reconstruction with a rib graft was performed in a total of 130 patients. After the cartilage specimens were prepared, the remaining grafts were used for study. The angle of warping in all grafts was measured at 0, 30, and 60 minutes; after 24 hours; and after 1 week. Eight subgroups of graft thicknesses from central and peripheral groups, determined according to the perichondral distance of the grafts, were evaluated, and the warping angles of 48 osteochondral and chondral grafts were measured individually. Three-way analysis of variance was used to compare the change in warping over time to detect differences in the grafts.

RESULTS

Significant differences were not observed in the 1- to 3-mm-thick grafts of peripheral and central origin before 30 minutes (p > 0.05), although significant differences were observed in these groups for all time points after 30 minutes (p < 0.05). In central and peripheral grafts thicker than 4 mm, a significant warping angle was not observed (p > 0.05). In central origin grafts thinner than 1 mm, significant differences were not observed in the warping angle (p > 0.05), although they were observed in the same grafts of peripheral origin (p < 0.05). Peripheral origin grafts thicker than 1 mm showed warping in the direction of the perichondrium (p < 0.05), whereas central origin grafts thinner than 1 mm showed warping angle irregularities.

CONCLUSION

Interlocking stresses are very important in rib grafts when balanced cross-sectional carving occurs from the peripheral to the central areas.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, V.

Influence of Laser Irradiation Low Intensity on Reparative Osteogenesis and Angiogenesis Under Transosseous Osteosynthesis

Introduction: The use of non-medicinal facilities of correcting processes for various pathological conditions is one of the most urgent problems of modern medicine. The purpose of the work is to study the efficiency of low-intensive of infrared laser irradiation in promoting reparative osteogenesis and angiogenesis during fracture treatment under transosseous osteosynthesis with a qualitative and quantitative morphological analysis. Methods: A tibial fracture was modeled experimentally in rats from control and experimental groups, then repositioning and fixation of fragments performed. The fracture zone of the experimental group animals was exposed to pulsed infrared laser irradiation of low intensity. The animals from control group underwent irradiation simulation. The operated bones were investigated using x-ray, light and electron microscopy, x-ray electron probe microanalysis. Results: The sessions of laser irradiation decreased inflammatory process severity, activated fibrillogenesis and angiogenesis, accelerated the compactization of newly formed bone tissue, and enhanced its maturity degree while primary healing occurred in the fracture. Conclusion: Laser therapy of fracture zone ensures the formation of regenerated bone and fragment union within earlier periods.

Namaste (counterbalancing) technique: Overcoming warping in costal cartilage

Background:

Indian noses are broader and lack projection as compared to other populations, hence very often need augmentation, that too by large volume. Costal cartilage remains the material of choice in large volume augmentations and repair of complex primary and secondary nasal deformities. One major disadvantage of costal cartilage grafts (CCG) which offsets all other advantages is the tendency to warp and become distorted over a period of time. We propose a simple technique to overcome this menace of warping.

Materials and Methods:

We present the data of 51 patients of rhinoplasty done using CCG with counterbalancing technique over a period of 4 years.

Results:

No evidence of warping was found in any patient up to a maximum follow-up period of 4 years.

Conclusion:

Counterbalancing is a useful technique to overcome the problem of warping. It gives liberty to utilize even unbalanced cartilage safely to provide desired shape and use the cartilage without any wastage.

Laser radiation effect on chondrocytes and intercellular matrix of costal and articular cartilage impregnated with magnetite nanoparticles

BACKGROUND AND OBJECTIVE

Magnetic nanoparticles with the ability to absorb laser radiation are the perspective agents for the early diagnostics and laser therapy of degenerative cartilage. The effect of starch stabilized magnetite nanoparticles (SSNPs) on the cartilage structure components has never been studied before. The aim of the work is to establish the Erbium:glass laser effect on costal and articular cartilage impregnated with SSNPs.

MATERIALS AND METHODS

Porcine articular and costal cartilage disks (2.0 mm in diameter and 1.5-2 mm in thickness) were impregnated with SSNPs and irradiated using a 1.56 μm laser in therapeutic laser setting. The one sample group underwent the second irradiation after the SSNPs impregnation. The samples were analyzed by the means of histology, histochemistry and transmission electron microscopy (TEM) to reveal the alterations of cells, glycosaminoglycans and collagen network.

RESULTS

The irradiated cartilage demonstrates the higher content of cell alterations than the intact one due to the heat and mechanical affection in the course of laser irradiation. However the alterations are localized at the areas near the irradiated surfaces and not dramatic. The impregnation of SSNPs does not cause any additional cell alterations. For both costal and articular cartilage the matrix alterations of irradiated samples are not critical: there is the slight decrease in acid proteoglycan content at the irradiated areas while the collagen network is not altered. Distribution and localization of impregnated SSNPs is described: agglomerates of 150-230 nm are observed located at the borders between matrix and cell lacunas of articular cartilage; SSNPs of 15-45 nm are found in the collagen network of costal cartilage.

CONCLUSIONS

It was shown that SSNPs do not appreciably affect the structural components of both articular and costal cartilage and can be safely used for the laser diagnostics and therapy. The area of structural alterations is diffuse and local as the result of the mechanical and heat effect of laser impact. SSNPs reveal the areas of the structural alterations of cartilage matrix and give information about the size of the pores and defects.

Precise and rapid costal cartilage graft sectioning using a novel device: clinical application

IMPORTANCE The use of costal cartilage as a graft in facial reconstructive surgery requires sectioning the cartilage into a suitable shape. OBJECTIVE To evaluate the accuracy of a novel mechanical device for producing uniform slices of costal cartilage and to illustrate the use of the device during nasal surgery. DESIGN Basic and clinical study using 100 porcine ex vivo costal cartilage slices and 9 operative cases. METHODS This instrument departs from antecedent devices in that it uses compression to secure and stabilize the specimen during sectioning. A total of 75 porcine costal cartilage ribs were clamped with minimal compression just sufficient to secure and stabilize the specimen while cutting. Slices having a length of 4 cm and width of 1 cm were obtained using the cartilage cutter at 3 thicknesses: 1 mm (n = 25), 2 mm (n = 25), and 3 mm (n = 25). The procedure was repeated for the 2-mm thick samples; however, the ribs in this group (n = 25) were clamped using the maximum amount of compression attainable by the device. Thickness was measured using a digital micrometer. Case presentations illustrate the use of the device in secondary and reconstructive rhinoplasty surgery. RESULTS All specimens were highly uniform in thickness on visual inspection and appeared to be adequate for clinical application. Sectioning was completed in several seconds without complication. In the porcine specimens sectioned using minimal compression, the percentage difference in thickness for each individual sample averaged 18%, 10%, and 11% for the 1-mm-, 2-mm-, and 3-mm-thick slices, respectively. Within the specimens sectioned using maximum compression, the percentage difference in thickness for each individual sample averaged 35% for the 2-mm-thick slices. In the setting of nasal reconstructive surgery, slices having a thickness from 1 to 2 mm were found to be well suited for all necessary graft types. CONCLUSIONS AND RELEVANCE The simple mechanical device described produces costal cartilage graft slices with highly uniform thickness. Securing the rib by clamping during cutting reduces uniformity of the slices; however, the imperfections are minimal, and all sectioned grafts are adequate for clinical application. The device can be adjusted to produce slices of appropriate thickness for all nasal cartilage grafts. This device is valuable for reconstructive procedures owing to its ease of use, rapid operation, and reproducible results.

Effects of carving plane, level of harvest, and oppositional suturing techniques on costal cartilage warping

BACKGROUND

Cartilage warping has plagued reconstructive and cosmetic rhinoplasty since the introduction of extra-anatomical cartilage use. With the present level of knowledge, there is no evidence of the warping properties with respect to cartilage harvest and suture techniques and level of rib harvest. This report aims to improve understanding of costal cartilage warping.

METHODS

The sixth through tenth costal cartilages were harvested from six fresh cadavers aged 54 to 90 years. Warping characteristics were followed with respect to level of harvest (i.e., sixth versus seventh), carving orientation, and oppositional suturing. Digital photography of the specimens was performed at various time points (immediately, 1 hour, and 1 month postoperatively).

RESULTS

All specimens showed signs of warping beyond 1 hour of carving that continued in a linear fashion to 1 month. There was no statistical difference in the amount of warping specific to the level of harvest, orientation, or with or without oppositional suturing (p<0.05).

CONCLUSIONS

Cartilage warping remains a problematic obstacle in nasal reconstruction and revision rhinoplasty, but costal cartilage remains the workhorse graft and is an excellent autologous option. Our findings are the first to be described in the literature regarding warping characteristics of costal cartilage with regard to the level of harvest, orientation of carving, and oppositional suturing techniques in a cadaveric model.

Ex vivo electromechanical reshaping of costal cartilage in the New Zealand white rabbit model

OBJECTIVES/HYPOTHESIS

Determine the effective electromechanical reshaping (EMR) parameters for shape change and cell viability in the ex vivo rabbit costal cartilage model.

STUDY DESIGN

Ex vivo animal study combined with computer modeling to guide electrode placement and polarity selection.

METHODS

Rabbit costal cartilages were secured in a jig that approximated the shape of the rabbit auricle framework. Finite element modeling was used to select the initial electrode geometry, polarity, spacing, and estimate dosimetry parameters. Porcine costal cartilage was utilized to refine the selection of dosing parameters. Parametric analysis was performed to determine the effect of voltage and application time on tissue shape change. Next, rabbit rib cartilage was reshaped, varying voltage and application time to identify the lowest parameters to produce acceptable shape change mimicking native auricular cartilage. Acceptable qualitative shape change was determined on a five-point Likert scale analyzed using one-way general linear analysis of variance. Confocal microscopy with live/dead cell viability analysis determined the degree of injury and the distribution of live and dead cells.

RESULTS

The minimum acceptable deformation of rabbit costal cartilage was found at 4 V-3 minutes. Viability analysis of cartilage reshaped at 4 V-3 minutes demonstrates cell injury extending 2 mm away from each electrode with viable cells found between the electrodes.

CONCLUSIONS

The EMR parameters of 4 V-3 minutes demonstrates appropriate shape change producing grafts that resemble the native auricle and contains the viable cells adequate for clinical evaluation. The rabbit auricular reconstruction model using EMR is a feasible one.

Electromechanical reshaping of costal cartilage grafts: a new surgical treatment modality

OBJECTIVES/HYPOTHESIS

Needle electrode-based electromechanical reshaping (EMR) is a novel, ultra-low-cost nascent surgical technology to reshape cartilage with low morbidity. EMR uses direct current to induce mechanical relaxation in cartilage that is first deformed into a required geometry, which in turn leads to permanent shape change. The objective of this study was to determine the effect of EMR voltage and time on the shape change of costal cartilage grafts.

STUDY DESIGN

EMR of ex vivo porcine costal cartilage.

METHODS

Graft specimens obtained from the central core of porcine costal cartilage were bent at a 90-degree angle with a custom jig and then reshaped via EMR. The effects of voltage (3-7 V) and application time (1-5 minutes) on the amount of shape change were systematically examined. Bend angles were analyzed using analysis of variance and paired t tests to determine significant reshaping times at each voltage setting.

RESULTS

There is a threshold for voltage and time above which the retention of bend angle is statistically significant in treated specimens compared to the control (P < .05). Above the threshold of 3 V, shape retention initially increased with application time for all voltages tested and was then observed to reach a plateau. Shape retention was noted to be greatest at 6 V without a rise in temperature.

CONCLUSIONS

EMR provides a novel method to bend and shape costal cartilage grafts for use in facial plastic surgery. A low voltage can reshape cartilage grafts within several minutes and without the heat generation. This study demonstrates the feasibility of EMR and brings this minimally invasive procedure closer to clinical implementation.

Laser-induced regeneration of cartilage

Laser radiation provides a means to control the fields of temperature and thermo mechanical stress, mass transfer, and modification of fine structure of the cartilage matrix. The aim of this outlook paper is to review physical and biological aspects of laser-induced regeneration of cartilage and to discuss the possibilities and prospects of its clinical applications. The problems and the pathways of tissue regeneration, the types and features of cartilage will be introduced first. Then we will review various actual and prospective approaches for cartilage repair; consider possible mechanisms of laser-induced regeneration. Finally, we present the results in laser regeneration of joints and spine disks cartilages and discuss some future applications of lasers in regenerative medicine.