Survival of diced and block cartilage grafts in combination with injectable calcium hydroxylapatite

The Role of Calcium Hydroxylapatite (Radiesse) as a Regenerative Aesthetic Treatment: A Narrative Review

For decades, a wide variety of natural and synthetic materials have been used to augment human tissue to improve aesthetic outcomes. Dermal fillers are some of the most widely used aesthetic treatments throughout the body. Initially, the primary function of dermal fillers was to restore depleted volume. As biomaterial research has advanced, however, a variety of biostimulatory fillers have become staples in aesthetic medicine. Such fillers often contain a carrying vehicle and a biostimulatory material that induces de novo synthesis of major structural components of the extracellular matrix. One such filler, Radiesse (Merz Aesthetics, Raleigh, NC), is composed of calcium hydroxylapatite microspheres suspended in a carboxymethylcellulose gel. In addition to immediate volumization, Radiesse treatment results in increases of collagen, elastin, vasculature, proteoglycans, and fibroblast populations via a cell-biomaterial-mediated interaction. When injected, Radiesse acts as a cell scaffold and clinically manifests as immediate restoration of depleted volume, improvements in skin quality and appearance, and regeneration of endogenous extracellular matrices. This narrative review contextualizes Radiesse as a regenerative aesthetic treatment, summarizes its unique use cases, reviews its rheological, material, and regenerative properties, and hypothesizes future combination treatments in the age of regenerative aesthetics.

LEVEL OF EVIDENCE: 5

The Effect of Rhinoplasty Dissection Planes (Sub-SMAS, Subperichondrial, and Subperiosteal) on the Viability of Diced Cartilage Grafts in a Rabbit Model

BACKGROUND

Dorsal preservation surgeries in which the subperichondral and subperiosteal planes are used to elevate the soft tissue envelope of the nose have become increasingly widespread because they can reduce postoperative edema and promote faster healing. However, the effects of surgical dissection planes on the viability of cartilage grafts are not known.

OBJECTIVE

The aim of this study was to determine, in a rabbit model, the viability of diced cartilage grafts in different rhinoplasty dissection planes (sub-superficial musculoaponeurotic system [SMAS], subperichondral, subperiosteal).

METHODS

Diced cartilage samples were placed in the sub-SMAS, subperichondrial, and subperiosteal planes, and after 90 days, histopathologic analysis was performed. Cartilage graft viability was evaluated based on the loss of chondrocyte nuclei in the lacuna, the presence of peripheral chondrocyte proliferation, and the loss of matrix metachromasia in the chondroid matrix.

RESULTS

The median [interquartile range] percentages of live chondrocyte nucleus viability in the sub-SMAS, subperichondrial, and subperiosteal groups were 67.5% [18.75%] (range, 60%-80%), 35% [17.5%] (range, 20%-45%), and 20% [30.0%] (range, 10%-45%), respectively; and the percentages of peripheral chondrocyte proliferation were 80.0% [22.5%] (range, 60%-90%), 30% [28.75%] (range, 15%-60%), and 20% [28.75%] (range, 5%-60%), respectively. There was strong statistical significance in both parameters (P = .001). Intergroup examination revealed a difference between the sub-SMAS and the other surgical planes (P = .001 for both parameters). A smaller loss of chondrocyte matrix was observed in the sub-SMAS group compared with the other 2 groups, which supports the findings of cartilage viability (P = .006).

CONCLUSIONS

Elevating the soft tissue envelope of the nose in the sub-SMAS surgical plane preserves the viability of cartilage grafts better than subperichondrial and subperiosteal elevation.

Cartilage Regeneration Units Based on Hydrogel Microcarriers for Injectable Cartilage Regeneration in an Autologous Goat Model

Despite numerous studies on tissue-engineered injectable cartilage, it is still difficult to realize stable cartilage formation in preclinical large animal models because of suboptimal biocompatibility, which hinders further application in clinical settings. In this study, we proposed a novel concept of cartilage regeneration units (CRUs) based on hydrogel microcarriers for injectable cartilage regeneration in goats. To achieve this goal, hyaluronic acid (HA) was chosen as the microparticle to integrate gelatin (GT) chemical modification and a freeze-drying technology to create biocompatible and biodegradable HA-GT microcarriers with suitable mechanical strength, uniform particle size, a high swelling ratio, and cell adhesive ability. CRUs were then prepared by seeding goat autologous chondrocytes on the HA-GT microcarriers and culturing in vitro. Compared with traditional injectable cartilage methods, the proposed method forms relatively mature cartilage microtissue in vitro and improves the utilization rate of the culture space to facilitate nutrient exchange, which is necessary for mature and stable cartilage regeneration. Finally, these precultured CRUs were used to successfully regenerate mature cartilage in nude mice and in the nasal dorsum of autologous goats for cartilage filling. This study provides support for the future clinical application of injectable cartilage.

Histomorphological Findings of Cartilage and Surrounding Tissues According to Thickness and Manipulations in Rabbits

BACKGROUND

Costal cartilage is commonly employed as a dorsal implant in Asian rhinoplasty. To achieve better outcomes, it is important to know which types of costal cartilage are most appropriate for dorsal augmentation.

OBJECTIVES

The authors investigated how various forms of costal cartilage affect the surrounding tissues and their resorption over time, as well as their clinical appearance, using histomorphological analysis.

METHODS

Cartilage samples were collected from the anterior chest wall of 10 rabbits. Four forms of cartilage-2-mm solid block, 1-mm solid block, diced, and crushed-were prepared and inserted into the subcutaneous tissue pockets of the nasal dorsum of each rabbit. The animals were killed 3 and 6 months later, and graft specimens were examined.

RESULTS

Histomorphological analysis revealed important findings of the cartilage and surrounding tissues. The thickness of thick cartilage significantly decreased over time, but the thickness of thin cartilage did not significantly change (P = 0.038). Additionally, the thick cartilages showed a lower degree of vascularization than the thin cartilages (P < 0.001). A comparison of the cartilage forms revealed that the diced cartilages had better chondrocyte survival than the solid block cartilages (P < 0.001). Fat tissues were prominently observed surrounding the diced cartilages at 3 months (P = 0.01), and fibrosis was more prominently observed in the crushed cartilage than in the other types of cartilages (P = 0.04 and P = 0.005 at 3 and 6 months, respectively).

CONCLUSIONS

This study revealed differences in resorption depending on the thickness of the costal cartilage in rabbits. Among the various forms of costal cartilages, diced and thin solid-block cartilage were the best option for dorsal augmentation when considering long-term graft survival.

Use of an Autologous Diced Cartilage Graft and Fat Graft Combination to Improve Regeneration in Rhinoplasty

BACKGROUND

In rhinoplasty, many techniques are used to increase the permanence of the planned final shape of the nose. Cartilage grafts can be diced and applied directly to the nasal dorsum, or by wrapping with a material. We aim to show that mixing and using diced cartilage grafts with fat grafts can contribute to the viability of cartilage grafts by comparing our early postoperative and long-term results.

MATERIALS AND METHODS

A total of 228 cases were analyzed. Postoperative 1-month, 6-month, and 1.5-year photographs of the patients were compared and the places that descended on the nasal dorsum were measured. In addition, dorsal height was measured and compared. Preoperative and postoperative first-year rhinoplasty outcome evaluation scales were performed. Specimens from 6 patients were examined histopathologically.

RESULTS

After the first month, the mean regression in the dorsum was measured as 1.4 mm. The decrease in dorsal height between 1 month and 6 months was significantly greater than the decrease between 6 months and late periods. According to the rhinoplasty outcome evaluation (ROE) scale, the average preoperative score of the patients was 45, while the mean postoperative score was 81.5. The viability of chondrocyte cells was measured as 85-90% histopathologically.

CONCLUSION

This approach has been evaluated as an application that satisfies both the surgeon and the patient due to the advantages of fat grafts such as preventing the cartilage and osteotomy lines from being palpated in thin-skinned patients, holding the diced cartilage grafts together by acting as a glue, increasing the viability of cartilage grafts.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine Ratings, please refer to Table of Contents or online Instructions to Authors www.springer.com/00266 .

Long-Term Results and Refinement of the Turkish Delight Technique for Primary and Secondary Rhinoplasty: 25 Years of Experience

BACKGROUND

All grafts present the potential problem of late visibility, distortion, and (occasionally) absorption. To overcome these problems and obtain a smoother surface, in 1989, the author initiated the use of finely diced cartilage wrapped in Surgicel. It is well known that the resolution of edema at the end of 1 year postoperatively is approximately 90 to 95 percent. Complete resolution continues until the end of 4 years postoperatively. However, it is important to understand what occurs beyond 4 years, and how the nose changes as the face ages.

METHODS

The author presents his experience of the past 25 years on 9398 primary and secondary rhinoplasty patients treated using his personal approach, the Turkish delight. Patients with a postoperative range from 4 to 25 years were selected.

RESULTS

The Turkish delight type of cartilage graft (diced cartilage wrapped in Surgicel) has been free of late show complications often experienced with other types of tip grafts. Long-term results from 4 to 25 years are very satisfactory, with an acceptably low complication rate.

CONCLUSIONS

This technique is safe, reliable, effective, simple, and easily applicable by plastic surgeons at all levels of experience. Early and long-term results from 1 to 25 years are very satisfactory. The overall complication rate is very low compared with other techniques. In addition, there is no late show as is sometimes seen with other types of cartilage grafts such as crushed, oval, or rectangular grafts.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.