The Effect of Perichondrium on Biological and Biomechanical Properties of Molded Diced Cartilage Grafts

Snake-shaped ePTFE nasal tip graft combined with conchal cartilage in Asian rhinoplasty: a retrospective cohort study

BACKGROUND

Lacking a nasal tip projection is a common deformity of Asian nasals. Various commonly used nasal tip grafts require dissecting septal perichondrium, most of them are autologous cartilage with a nonintegrated design. A snake-shaped expanded polytetrafluoroethylene (ePTFE) nasal tip graft is an integrated, stable tip graft without any additional assembly and splicing, conforming to the nasal anatomy characteristics of Asians.

METHOD

A retrospective study was performed on Asian patients who underwent rhinoplasty in the nasal tip at Peking University Third Hospital from 2015 to 2022. Nasal tip grafts were categorized into three groups: snake-shaped ePTFE combined with conchal cartilage (n = 15), only costal cartilage (n = 25), and only conchal cartilage (n = 17). Patients were excluded if their rhinoplasty did not involve any of the grafts above. Visual Analogue Scale, FACE-Q Nose, FACE-Q Nostril, Nasal Obstruction Symptom Evaluation scale, and Rhinoplasty Outcome Evaluation scale were used to evaluate the preoperative and postoperative results.

RESULTS

Fifty-three (93.0%) cases had low nasal dorsum and 46 (80.7%) cases had short nose. There was no significant difference in complication rates among the three groups. The difference between preoperative and postoperative scale scores was statistically significant among the three groups (p < 0.05). Score improvements, including all scales, were the highest in the costal cartilage group and lowest in the conchal cartilage group.

CONCLUSIONS

Snake-shaped ePTFE nasal tip grafts can be an effective integrated alternative that provides long-term safety and efficacy compared with traditional autogenous implants (conchal and costal cartilages).

Comparison of Different Suture Techniques on Nasal Soft Tissue Envelope to Prevent Supratip Deformity: A Histologic Study

BACKGROUND

Studies have described various surgical maneuvers in rhinoplasty to limit thickening from excessive scarring in the supratip region. This study aimed to compare the effectiveness of three maneuvers-a simple suture, a U suture, and bolster dressing-used to avoid supratip deformity in a rabbit model.

METHODS

Thirty-two male New Zealand white rabbits were included. The animals were divided into four groups, and dissection was performed in the supra-perichondrial plane up to the supratip region through an open rhinoplasty incision. After dissection, the following approaches were applied to the supratip region: Group 1, simple approximation suture; Group 2, U suture; Group 3, bolster dressing; and Group 4 (control group), no suture. All animals were sacrificed after 12 weeks. Histological analysis was performed.

RESULTS

In Group 4, scar thickness was significantly greater than in the other groups (p < 0.05). Group 3 had greater scar thickness than Group 2 (p < 0.05). The ratio of scar thickness to skin thickness was higher in Group 4 compared with the other groups (p < 0.05). Finally, there was no difference in the ratio of scar thickness to skin thickness between Groups 1, 2, and 3 (p > 0.05).

CONCLUSIONS

In this study, it was concluded that surgical methods using sutures in the supratip region reduced scar thickness in a rabbit model, and these surgical methods had similar levels of effectiveness.

NO LEVEL ASSIGNED

This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Promotion of diced cartilage survival and regeneration with grafting of small intestinal submucosa loaded with urine-derived stem cells

Cartilage absorption and calcification are prone to occur after the implantation of diced cartilage wrapped with autologous materials, as well as prolong the operation time, aggravate surgical trauma and postoperative pain during the acquisition process. Small intestinal submucosa (SIS) has suitable toughness and excellent degradability, which has been widely used in the clinic. Urine-derived stem cells (USCs), as a new type of stem cells, have multi-directional differentiation potential. In this study, we attempt to create the tissue engineering membrane material, termed USCs-SIS (U-SIS), and wrap the diced cartilage with it, assuming that they can promote the survival and regeneration of cartilage. In this study, after co-culture with the SIS and U-SIS, the proliferation, migration and chondrogenesis ability of the auricular-derived chondrocyte cells (ACs) were significantly improved. Further, the expression levels of chondrocyte phenotype-related genes were up-regulated, whilst that of dedifferentiated genes was down-regulated. The signal pathway proteins (Wnt3a and Wnt5a) were also participated in regulation of chondrogenesis. In vivo, compared with perichondrium, the diced cartilage wrapped with the SIS and U-SIS attained higher survival rate, less calcification and absorption in both short and long terms. Particularly, USCs promoted chondrogenesis and modulated local immune responses via paracrine pathways. In conclusion, SIS have the potential to be a new choice of membrane material for diced cartilage graft. U-SIS can enhance survival and regeneration of diced cartilage as a bioactive membrane material.

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.

Combining Diced Cartilage with Chondrocyte Spheroids in GelMA Hydrogel: An Animal Study in Diced Cartilage Grafting Technique

BACKGROUND

The phenotype maintenance of diced cartilage is a very important factor to reduce cartilage absorption rate in augmentation rhinoplasty. A novel method which combined diced cartilage with chondrocyte spheroids in gelatin methacrylate (GelMA) hydrogel may have potentially good performance in phenotype maintenance, and is worth exploring.

METHODS

The complex grafts formed by loading diced cartilage with chondrocyte spheroids into GelMA hydrogel were used as the experimental group, and the grafts formed of diced cartilage in GelMA were used as the control group. The two groups of grafts were implanted subcutaneously in nude mice. After 1 month and 3 months, the grafts were taken for general observation and histological analysis. The diameter changes of cartilage, the nuclei loss of chondrocyte, and glycosaminoglycan secretion were analyzed.

RESULTS

Chondrocyte spheroids with obvious proliferation can be seen in the experimental group. Some diced cartilages had become a whole through the interconnection of chondrocyte spheroids. In addition, the diameter of the chondrocyte spheroids-diced cartilage complex in the experimental group increased significantly, and its nuclei loss rate was less than 1/2 of that in the control group. The maintenance of proteoglycans in diced cartilages in the experimental group was significantly better than that in the control group.

CONCLUSION

The combination of diced cartilage with chondrocyte spheroids in GelMA hydrogel can significantly reduce the absorption of cartilage extracellular matrix, enhance phenotype maintenance during subcutaneous ectopic implantation, and can produce inter-chondral connections.

Mechanical properties of extensive calcified costal cartilage: An experimental study

Background

Autologous costal cartilage is widely used as nasal augmentation or nasal reconstruction material. However, no study has focused on the mechanical difference between no calcified costal cartilage and extensive calcified costal cartilage at present. Our study aims to study the loading behavior of calcified costal cartilage under tensile and compressive stress.

Method

Human costal cartilage specimen was obtained from five extensive calcified costal cartilage patients and classified into four groups (group A: no calcified costal cartilage; group B: calcified costal cartilage; group C: no calcified costal cartilage after transplantation in BALB/c nude mice for half a year; group D: calcified costal cartilage after transplantation in BALB/c nude mice for half a year). Young's modulus, stress relaxation slope, and relaxation amount were analyzed through tensile and compressive tests using a material testing machine.

Results

We included five female patients with extensive calcified costal cartilage. Group B exhibited significantly higher Young's modulus in both the tensile and compressive tests (p < 0.05 in tensile test, p < 0.01 in compressive test), higher relaxation slope (P < 0.01) and higher relaxation amount (p < 0.05 in compression test). After transplantation, the Young's modulus of calcified and non-calcified costal cartilage decreased, except that the calcified costal cartilage increased slightly in the tensile test. The final relaxation slope and relaxation amount had increased at different degrees, but the changes did not change significantly before and after transplantation (P > 0.05).

Conclusion

Our results showed that the stiffness of calcified cartilage would increase 30.06% under tension and 126.31% under compression. This study may provide new insights to researchers focusing on extensive calcified costal cartilage can be used for autologous graft material.

The effect of perichondrium on cartilage graft properties

PURPOSE OF REVIEW

The role of perichondrium in cartilage graft survival has been long debated. Although the innate function of perichondrium in providing mechanical and regenerative support to cartilage in its native position is relatively undisputed, studies continue to vacillate over how the perichondrium effects cartilage grafts once transplanted. This review evaluates historical and recent experiments showing how perichondrium may or may not impact graft survival.

RECENT FINDINGS

Experimental studies in animal models have more recently evaluated macroscopic and microscopic properties of diced cartilage grafts with and without perichondrium, finding that in general grafted cartilage with perichondrial components retains greater weight and mechanical strength compared with cartilage without perichondrial components. However, these findings have not been replicated in humans. Solid pieces of rib cartilage have most recently been used without perichondrium to prevent warping, though no studies have evaluated whether retaining perichondrium with oblique and concentric cutting techniques may effect overall resorption.

SUMMARY

Although historical opinions and more recent animal studies suggest a role of perichondrium in cartilage graft survival, randomized controlled human studies are still lacking on whether retaining perichondrium truly effects graft survival and ultimate surgical outcomes.

The Effect of Perichondrium and Graft Modification on the Viability of Conchal Cartilage Graft: An Experimental Study in Rabbit

OBJECTIVE

Cartilage grafts are widely used in reconstructing nasal deformity for structural and aesthetic purposes. Despite being immunologically privileged, cartilage grafts are susceptible to volume loss with high risk of resorption over time. Therefore, experts opt for cartilage handling modification to resolve this issue through graft dicing, wrapping, or perichondrium preservation. This study will evaluate the effect cartilage graft preparations on graft viability.

DESIGN

Single-randomized post-test-only study design.

SETTING

Animal Hospital at Bogor Agricultural Institute.

PARTICIPANTS

Six New Zealand, male, Hycole rabbits.

INTERVENTION

Conchal cartilage grafts were retrieved from 6 experimental rabbits and distributed into 3 treatment groups: diced cartilage graft (DC; control), one-sided perichondrium-attached scored cartilage (OPSC), and tube-shaped perichondrium-wrapped diced cartilage (TPDC).

MAIN OUTCOME MEASURES

Macroscopic (weight and contour) and microscopic (chondroblast proliferation, graft thickness, apoptotic cells) evaluation through histological measures were recorded on week 12. Statistical analysis was done to compare between groups.

RESULTS

Diced cartilage and OPSC groups showed significant weight changes on week 12 (P < .05) with OPSC presenting with the biggest difference. Diced cartilage and OPSC group showed moderate cell proliferation on week 12 while TPDC displayed most abundant apoptotic cells (5.8%; P < .05). Diced cartilage group had the highest cartilage thickness ratio (P < .05).

DISCUSSION

Bare DC technique promoted graft thickness while perichondrium-attached scored cartilage showed the most abundant chondroblast proliferation and the least apoptotic cells. Perichondrium contributes to enhanced new cartilage formation.

CONCLUSION

Diced cartilage graft is suitable for masking irregularity and volume augmentation, while perichondrium-attached cartilage graft is better for structural support in nasal reconstruction.

Diced Cartilage Techniques in Rhinoplasty

Diced cartilage has been widely applied in rhinoplasty, especially for segmental dorsal augmentation, with favorable outcomes over time. Various techniques were developed to increase both stability and viability of diced cartilage, including wrappings with non-blood material/blood products and changing the shapes of the diced cartilage, while the optimal technique is inconclusive. This article systematically reviews the current strategies of diced cartilage technique for rhinoplasty in the databases and emphasizes different wrapping materials. Free diced cartilage has a potential risk of gathering in certain regions and causing postoperative irregularities. Among non-blood wrapping materials, Surgicel is now rarely used due to severe foreign body reactions. The obvious drawbacks of fascia are donor site morbidity, inadequate quantity, and time-consuming. Although diced cartilage wrapped in tutoplast-processed fascia lata, AlloDerm, or esterified hyaluronic acid has achieved primary encouraging results, the increased inflammation raised controversies regarding their clinical use. Diced cartilage wrapped with blood products, such as platelet-rich fibrin or concentrated growth factor, achieved long-term reliable aesthetic results, and shaved cartilage and ultra-diced cartilage have recently shown satisfactory clinical outcomes, while further study is still needed. 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 the Table of Contents or the online Instructions to Authors www.springer.com/00266 .