Carbon dioxide laser-assisted cartilage reshaping otoplasty: A new technique for prominent ears

Laser-Assisted Rhinoplasty: The Future Generation Rhinoplasty Technique to Preserve Anatomy? A Series of Patients Compared to Patients Undergoing Standard Open Rhinoplasty

BACKGROUND

Rhinoplasty is the cosmetic procedure that is most difficult to master. Anatomical preservation should represent the main goal of rhinoplasty. One emerging tool appears to be erbium:yttrium-aluminum-garnet laser bone and cartilage reshaping. The authors developed a new small laser hand probe to perform what we called laser-assisted rhinoplasty. The authors evaluate the feasibility of the laser-assisted rhinoplasty and the aesthetic and functional result of laser-assisted rhinoplasty compared to classic rhinoplasty.

METHODS

A total of 50 patients were enrolled and randomized into two cohorts: the first cohort of patients was submitted to classic rhinoplasty, and the second cohort to laser-assisted rhinoplasty. The laser beam was used to perform both the resection of the crura and the resection of the nasal hump and osteotomies.

RESULTS

Laser-assisted rhinoplasty is a safe and reproducible technique. At a clinical assessment, lateral crura reshaping showed a visible step or excessive skin retraction in 12 percent of the classic rhinoplasty population with thick cartilage and/or thin skin, and this was not present in the laser-assisted rhinoplasty population at 12-month follow-up. The patient satisfaction rate was higher in the laser-assisted rhinoplasty population compared with standard open rhinoplasty. The authors also clinically noted a reduction in edema in the immediate postoperative period in the laser-assisted rhinoplasty population and a more rapid complete resolution of the swelling.

CONCLUSION

The laser-assisted rhinoplasty technique is feasible and safe and has no major complication, and the aesthetic and functional results can be superimposed onto classic rhinoplasty but with a higher degree of intraoperative precision, higher patient satisfaction, a cleaner field, and less bleeding.

Repopulation of decellularised articular cartilage by laser-based matrix engraving

BACKGROUND

In spite of advances in the treatment of cartilage defects using cell and scaffold-based therapeutic strategies, the long-term outcome is still not satisfying since clinical scores decline years after treatment. Scaffold materials currently used in clinical settings have shown limitations in providing suitable biomechanical properties and an authentic and protective environment for regenerative cells. To tackle this problem, we developed a scaffold material based on decellularised human articular cartilage.

METHODS

Human articular cartilage matrix was engraved using a CO₂ laser and treated for decellularisation and glycosaminoglycan removal. Characterisation of the resulting scaffold was performed via mechanical testing, DNA and GAG quantification and in vitro cultivation with adipose-derived stromal cells (ASC). Cell vitality, adhesion and chondrogenic differentiation were assessed. An ectopic, unloaded mouse model was used for the assessment of the in vivo performance of the scaffold in combination with ASC and human as well as bovine chondrocytes. The novel scaffold was compared to a commercial collagen type I/III scaffold.

FINDINGS

Crossed line engravings of the matrix allowed for a most regular and ubiquitous distribution of cells and chemical as well as enzymatic matrix treatment was performed to increase cell adhesion. The biomechanical characteristics of this novel scaffold that we term CartiScaff were found to be superior to those of commercially available materials. Neo-tissue was integrated excellently into the scaffold matrix and new collagen fibres were guided by the laser incisions towards a vertical alignment, a typical feature of native cartilage important for nutrition and biomechanics. In an ectopic, unloaded in vivo model, chondrocytes and mesenchymal stromal cells differentiated within the incisions despite the lack of growth factors and load, indicating a strong chondrogenic microenvironment within the scaffold incisions. Cells, most noticeably bone marrow-derived cells, were able to repopulate the empty chondrocyte lacunae inside the scaffold matrix.

INTERPRETATION

Due to the better load-bearing, its chondrogenic effect and the ability to guide matrix-deposition, CartiScaff is a promising biomaterial to accelerate rehabilitation and to improve long term clinical success of cartilage defect treatment.

FUNDING

Austrian Research Promotion Agency FFG ("CartiScaff" #842455), Lorenz Böhler Fonds (16/13), City of Vienna Competence Team Project Signaltissue (MA23, #18-08).

Repopulation of decellularised articular cartilage by laser-based matrix engraving

Background

In spite of advances in the treatment of cartilage defects using cell and scaffold-based therapeutic strategies, the long-term outcome is still not satisfying since clinical scores decline years after treatment. Scaffold materials currently used in clinical settings have shown limitations in providing suitable biomechanical properties and an authentic and protective environment for regenerative cells. To tackle this problem, we developed a scaffold material based on decellularised human articular cartilage.

Methods

Human articular cartilage matrix was engraved using a CO₂ laser and treated for decellularisation and glycosaminoglycan removal. Characterisation of the resulting scaffold was performed via mechanical testing, DNA and GAG quantification and in vitro cultivation with adipose-derived stromal cells (ASC). Cell vitality, adhesion and chondrogenic differentiation were assessed. An ectopic, unloaded mouse model was used for the assessment of the in vivo performance of the scaffold in combination with ASC and human as well as bovine chondrocytes. The novel scaffold was compared to a commercial collagen type I/III scaffold.

Findings

Crossed line engravings of the matrix allowed for a most regular and ubiquitous distribution of cells and chemical as well as enzymatic matrix treatment was performed to increase cell adhesion. The biomechanical characteristics of this novel scaffold that we term CartiScaff were found to be superior to those of commercially available materials. Neo-tissue was integrated excellently into the scaffold matrix and new collagen fibres were guided by the laser incisions towards a vertical alignment, a typical feature of native cartilage important for nutrition and biomechanics. In an ectopic, unloaded in vivo model, chondrocytes and mesenchymal stromal cells differentiated within the incisions despite the lack of growth factors and load, indicating a strong chondrogenic microenvironment within the scaffold incisions. Cells, most noticeably bone marrow-derived cells, were able to repopulate the empty chondrocyte lacunae inside the scaffold matrix.

Interpretation

Due to the better load-bearing, its chondrogenic effect and the ability to guide matrix-deposition, CartiScaff is a promising biomaterial to accelerate rehabilitation and to improve long term clinical success of cartilage defect treatment.

Funding

Austrian Research Promotion Agency FFG (“CartiScaff” #842455), Lorenz Böhler Fonds (16/13), City of Vienna Competence Team Project Signaltissue (MA23, #18-08)

[Preliminary study on microdissection needle-assisted ear cartilage reshaping in vivo rabbit models]

Objective

To preliminarily investigate morghological changes of rabbits reshaping ear cartilage assisted by microdissection needle and explore feasibility of new therapy for ear deformity.

Methods

The bilateral ears of 5 male New Zealand rabbits (aged, 5-6 months) were fixed maintaining the curvature and randomly divided into 2 groups (5 ears in each group). The ears were stimulated by microdissection needle in experimental group and were not treated with stimulation in control group. The skin reaction in the experimental group was observed immediately and at 4 weeks after stimulation. Then, the fixtures were removed at 4 weeks, and the shapes of the ears were observed. The cartilages were harvested from the ears to examined morphological changes after HE staining, and measured the chondrocyte layer thickness.

Results

All rabbits survived until the end of the experiment. The skin has healed completely after 4 weeks in experimental group. After removing fixtures, the ears in the two groups all maintained certain forms momentarily; while 24 hours later, the ears in the control group mostly recovered original form, and the ears in the experimental group still maintained certain molding form until 8 weeks. HE staining showed there were smooth cartilage and uniform distribution of cells in the control group; the matrix staining was basically consistent; and the skin was normal appearance with epidermis, dermis, and cartilage of normal aspect. But the proliferation of chondrocyte with more layers of cells were observed in the experimental group. In addition, there were degeneration and injury of cartilage cells and connective tissue with necrotic cells and inflammatory cells at needle insertion sites. The chondrocyte layer thickness was (385.714±2.027) μm in the control group and (1 594.732±1.872) μm in the experimental group, there was significant difference between the two groups ( t=-759.059, P=0.000).

Conclusion

Rabbit ear cartilage can be effectively reshaped by microdissection needle. Proliferation of chondrocyte and changes in matrix can be found during the reshaping process.

[Current progress of laser-assisted cartilage reshaping for prominent ear]

Objective

To summarize the current progress of laser-assisted cartilage reshaping (LACR) for prominent ear.

Methods

The domestic and abroad article concerning the LACR in treatment of prominent ear was reviewed and analyzed.

Results

As a new technique, there were three types of LACR therapies that been used for prominent ear. LACR with the 1 064 nm Nd/YAG laser is painful and the penetration depth of the 1 064 nm Nd/YAG laser is greater than that of the 1540 nm Er/Glass laser which is caused more tissue injury. LACR with the 1 540 nm Er/Glass laser has high absorption by the ear cartilage and produce less injury to the surrounding tissue. Use of the CO ₂ laser permitted cartilage reshaping combined with both vaporization and incisions, which complicates the technique, although, with low recurrence rate and definite effect. Insisting on wearing ear mold is the key to get satisfactory effectiveness for postoperative patients. The complications of LACR for prominent ear, such as the dermatitis, perforation of the skin, hematoma, or infection, should be noticed.

Conclusion

Application of LACR for prominent ear just has a short period of time, limited number of cases, and few relevant literature reports. Its effectiveness needs to be further studied and clarified.

Monitoring of Biological Changes in Electromechanical Reshaping of Cartilage Using Imaging Modalities

Electromechanical reshaping (EMR) is a promising surgical technique used to reshape cartilage by direct current and mechanical deformation. It causes local stress relaxation and permanent alterations in the shape of cartilage. The major advantages of EMR are its minimally invasive nature and nonthermal electrochemical mechanism of action. The purpose of this study is to validate that EMR does not cause thermal damage and to observe structural changes in post-EMR cartilage using several imaging modalities. Three imaging modality metrics were used to validate the performance of EMR by identifying structural deformation during cartilage reshaping: infrared thermography was used to sense the temperature of the flat cartilages (16.7°C at 6 V), optical coherence tomography (OCT) was used to examine the change in the cartilage by gauging deformation in the tissue matrix during EMR, and scanning electron microscopy (SEM) was used to show that EMR-treated cartilage is irregularly arranged and the thickness of collagen fibers varies, which affects the change in shape of the cartilage. In conclusion, the three imaging modalities reveal the nonthermal and electromechanical mechanisms of EMR and demonstrate that use of an EMR device is feasible for reshaping cartilage in a minimally invasive manner.

Otoplasty with an unusual cartilage scoring approach

BACKGROUND

An ideal otoplasty procedure should minimise the possible risk of severe complications of otoplasty and provide a good aesthetic outcome; however, there is no standart technique to be applied to all types of auricular deformities in different populations. The aim of this study was to present an otoplasty technique with posterior approach in which small incomplete cartilage incisions and suture fixations were used to form the auricle without a need for anterior skin incision and dissection.

METHODS

This study involved 42 patients who had bilateral prominent ears with unfurled antihelixes associated with or without conchal excess. The otoplasty procedure mainly consisted of a posterior skin excision, incomplete cartilage incisions in the shape of greater mark, ">", mattress sutures of the posterior cartilage, earlobe correction, and conchal reduction if necessary.

RESULTS

This otoplasty technique consists of easy, simple, and rapid surgical steps without a need for anterior skin dissection and cartilage scoring, so it has a low rate of complications in both early and late postoperative periods. Follow-up time of patients ranged from 1-9 years, with an average of 3 years. No major complications such as haematomas, chondritis, wound infection, skin necrosis, asymmetry, recurrence, hypertrophic scars, granulomas, or irregularities developed in the early and late postoperative periods. A good symmetry and natural appearence were achieved with this otoplasty technique. Patients were satisfied with the results. All over complication rate in the postoperative period was 7%.

CONCLUSION

The presented technique overcomes the drawbacks of anterior skin dissection and anterior scoring, and minimises the risk of severe complications such as anterior skin necrosis, cartilage necrosis or destruction, and ear irregularities. It also reduces the operation time, swelling, bruising, and possibility of suture extrusion and recurrence.

1064-nm Nd: YAG laser-assisted cartilage reshaping for treating ear protrusions

BACKGROUND

Correction of prominent ears is a common plastic surgical procedure. The laser-assisted cartilage reshaping (LACR) technique for protruding ears was developed at the French National Institute of Health and Medical Research in Lille, France, using both the 1064- and 1540-nm wavelengths, with a view to simplifying the surgical procedure. Herein we report our results with the 1064-nm wavelength.

METHODS

Between 2008 and 2010, twenty-six 1064-nm LACR procedures in 14 patients were performed. Twelve patients received treatment to both ears, and 2 patients received treatment to one ear. Each procedure consisted of a single treatment session. The treatment consisted of laser irradiation of both sides of the helix with single pulses of 70 J/cm2. The beam diameter was 6 mm. Early and late complications were defined and reviewed for all patients. Satisfaction was assessed by patients using a visual analogue scale from 0 (unsatisfied) to 20 (highly satisfied). The superior and middle cephaloauricular distances were prospectively evaluated at 6 months after treatment.

RESULTS

Complications included eight cases of localized skin burns and one case of dermatitis. The mean right/left superior and middle cephaloauricular distances were 10.5±1.5 mm/10.7±1.0 mm and 16.3±2.2 mm/16.3±2.8 mm, respectively, as compared to 17.5±2.9 mm/18.6±2.5 mm (P<0.01) and 24.5±2.6 mm/24.7±1.7 mm (P<0.01) before the operation. Mean patient satisfaction was 16.8/20±3.3.

CONCLUSION

Despite promising results for cartilage reshaping, the 1064-nm LACR procedure often leads to skin burns and inflammatory tissue reaction after treatment. Moreover, LACR with the 1064-nm wavelength is painful and necessitates local anaesthesia.

LEVEL OF EVIDENCE

4.

Laser-assisted cartilage reshaping for protruding ears: A review of the clinical applications

OBJECTIVES/HYPOTHESIS

In 2006, our institute reported the first clinical use of laser-assisted cartilage reshaping (LACR) for protruding ears. Since then, the technique has been developed and refined. This article reviews the literature on the clinical application of LACR.

STUDY DESIGN

Literature review.

METHODS

A MEDLINE literature search was performed on LACR combined with cross-referencing. The period of search was 1993 to 2014. Search terms used were: laser, cartilage reshaping, protruding ears, LACR.

RESULTS

Only seven clinical studies using three different wavelengths were found in the literature: 1,064 nm (Nd:YAG), 10,600 nm (CO2), and 1540 nm (Er:Glass). Clinical outcomes, laser wavelength and parameters, and patient satisfaction are discussed in each case.

CONCLUSIONS

The success rate for ear reshaping achieved with LACR appears promising. The use of this noninvasive technique will increase in the near future.

In vivo needle-based electromechanical reshaping of pinnae: New Zealand White rabbit model

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 SPECIMENS

In 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 MEASURES

The 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.

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.

Ex vivo investigations of laser auricular cartilage reshaping with carbon dioxide spray cooling in a rabbit model

Laser cartilage reshaping (LCR) with cryogen spray cooling is a promising modality for producing cartilage shape change while reducing cutaneous thermal injury. However, LCR in thicker tissues, such as auricular cartilage, requires higher laser power, thus increasing cooling requirements. To eliminate the risks of freeze injury characteristic of high cryogen spray pulse rates, a carbon dioxide (CO2) spray, which evaporates rapidly from the skin, has been proposed as the cooling medium. This study aims to identify parameter sets which produce clinically significant reshaping while producing minimal skin thermal injury in LCR with CO2 spray cooling in ex vivo rabbit auricular cartilage. Excised whole rabbit ears were mechanically deformed around a cylindrical jig and irradiated with a 1.45-μm wavelength diode laser (fluence 12-14 J/cm(2) per pulse, four to six pulse cycles per irradiation site, five to six irradiation sites per row for four rows on each sample) with concomitant application of CO2 spray (pulse duration 33-85 ms) to the skin surface. Bend angle measurements were performed before and after irradiation, and the change quantified. Surface temperature distributions were measured during irradiation/cooling. Maximum skin surface temperature ranged between 49.0 to 97.6 °C following four heating/cooling cycles. Significant reshaping was achieved with all laser dosimetry values with a 50-70 °C difference noted between controls (no cooling) and irradiated ears. Increasing cooling pulse duration yielded progressively improved gross skin protection during irradiation. CO2 spray cooling may potentially serve as an alternative to traditional cryogen spray cooling in LCR and may be the preferred cooling medium for thicker tissues. Future studies evaluating preclinical efficacy in an in vivo rabbit model are in progress.

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.