A systematic review and meta-analysis of comparison between autologous costal cartilage and alloplastic materials in rhinoplasty

A Contemporary Review of Trachea, Nose, and Ear Cartilage Bioengineering and Additive Manufacturing

The complex structure, chemical composition, and biomechanical properties of craniofacial cartilaginous structures make them challenging to reconstruct. Autologous grafts have limited tissue availability and can cause significant donor-site morbidity, homologous grafts often require immunosuppression, and alloplastic grafts may have high rates of infection or displacement. Furthermore, all these grafting techniques require a high level of surgical skill to ensure that the reconstruction matches the original structure. Current research indicates that additive manufacturing shows promise in overcoming these limitations. Autologous stem cells have been developed into cartilage when exposed to the appropriate growth factors and culture conditions, such as mechanical stress and oxygen deprivation. Additive manufacturing allows for increased precision when engineering scaffolds for stem cell cultures. Fine control over the porosity and structure of a material ensures adequate cell adhesion and fit between the graft and the defect. Several recent tissue engineering studies have focused on the trachea, nose, and ear, as these structures are often damaged by congenital conditions, trauma, and malignancy. This article reviews the limitations of current reconstructive techniques and the new developments in additive manufacturing for tracheal, nasal, and auricular cartilages.

Saddle Nose Deformity Reconstruction with a Allograft Bone

OBJECTIVE

Providing lasting cosmetic and functional results for patients with saddle nose deformity with allograft.

METHODS

This report describes experience with using a of freeze-dried allograft bone allograft in 58 patients who underwent dorsal augmentation over 5-year period (2018-2023). Thirty-eight patients had saddle-shaped deformity of the nose, and 16 patients had post-traumatic cases with saddle nose deformities. All patients underwent a clinical examination using computed tomography. Before surgery using a 3D model, the graft was contoured according to the shape of the nasal defect. The grafts were installed using a closed approach and were placed under the periosteum of the bone. Using lateral photographs, anthropometric measurements of the nose were taken before and after surgery to assess aesthetic outcome after surgery. To assess the results of aesthetic rhinoplasty (UQ), the Portuguese version of the Utrecht Questionnaire was used, which contains a visual analogue scale (VAS) on a 5-point Likert scale.

RESULTS

A total of 56 patients were satisfied with the results of the surgical procedure. No complications or major graft resorption was observed. An analysis comparing preoperative and 1-year follow-up data using 3D scanning showed a significant increase in dorsal height without dorsal expansion. After rhinoplasty, the mean visual analog scale (VAS) aesthetic score improved significant from 2.3 preoperatively, 3 months postoperatively 8.4, and 8.9 1 year postoperatively.

CONCLUSION

The use of freeze-dried allograft bone is a useful method of dorsal augmentation in rhinoplasty without donor site complications.

LEVEL OF EVIDENCE II

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 .

M-Shaped Auricular Cartilage Grafts for Correcting Short Nose Deformity in Asians: A Retrospective Study

BACKGROUND

The demand for rhinoplasty in Asia is growing annually, and short nose deformity has been one of the main reasons for the surgery due to its high incidence. There is an urgent need for rhinoplasty suitable for Asians because of their different facial features from Westerners. The M-shaped auricular cartilage rhinoplasty has been developed as a new method for correcting short nose deformity for Asians. This study aimed to evaluate the aesthetic and functional results of M-shaped auricular cartilage rhinoplasty compared to clinically commonly used rhinoplasty methods.

METHODS

A total of 45 patients were enrolled and divided into three groups of 15 patients: The first group underwent M-shaped auricular cartilage rhinoplasty, the second group underwent auricular-septal cartilage rhinoplasty, and the third group underwent overlapped auricular cartilage rhinoplasty. All of these patients underwent comprehensive rhinoplasty and had silicone or expanded polytetrafluoroethylene implants in the dorsum of their noses.

RESULTS

The patient score improvements on the three patient-reported outcome measures were higher in the M-shaped auricular cartilage rhinoplasty group (1.65/1.79/0.11) compared with the overlapped auricular cartilage rhinoplasty group (1.40/1.51/0.05), and the score improvements in the auricular-septal cartilage rhinoplasty group (2.04/1.98/0.28) were the highest.

CONCLUSIONS

This is a retrospective clinical study demonstrating the clinical efficacy of M-shaped auricular cartilage rhinoplasty. Compared with the overlapped auricular cartilage rhinoplasty, the effect of this novel M-shaped method is better. However, when compared to the auricular-septal cartilage rhinoplasty with septal extension and reinforcement using nasal septal cartilage, its effect is slightly worse.

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 .

Fresh Frozen Cartilage in Rhinoplasty Surgery: A Systematic Review of Outcomes

INTRODUCTION

Cadaveric fresh frozen cartilage provides an enticing alternative to traditional autologous cartilage grafts. This review provides a systematic analysis of existing literature on the use of fresh frozen rib for in rhinoplasties and focuses on clinical and aesthetic outcomes.

METHODS

The methodology was designed and registered in the PROSPERO database (CRD42023447166). The Preferred Reporting Items for Systematic Reviews and Meta-Analysis guideline was used to perform this systematic review.

RESULTS

Four articles were included, with a total of 554 patients. A total of 477 patients were female (86%). Mean age ranged between 35.8 and 40.6. Mean follow-up ranged from 12.2 to 20.3 months. Only one article had a suitable control (with autologous rib graft). Pooled complications rates were low. Infection occurred in 12 patients (2%), warping in 8 patients (1.4%) and resorption in 3 patients (0.5%).

CONCLUSION

Fresh frozen cartilage may be a safe and reliable alternative to autologous rib grafts. Complication rates were comparable to previous systematic reviews of autologous graft and irradiated allograft. Overall, patients reported high satisfaction rates with low rates of revision procedures. Further studies are required to assess both clinical and cost effectiveness against the current gold standard (autologous graft).

LEVEL OF EVIDENCE III

Rhinoplasty. 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 .

Use of human acellular dermal matrix in rhinoplasty: a systematic review of the literature and meta-analysis

Alloplastic implants such as acellular dermal matrix (ADM) have been used for various aesthetic and reconstructive purposes since the 1990s. Rhinoplasty addresses both aesthetic and functional nasal impairments, often involving the adoption of grafting materials. Currently, autologous grafts, such as those using septal cartilage, are the gold standard. However, they pose the risk of donor site morbidity, technical challenges, and additional operative time. We review total complications, resorption/re-operation and success rates associated with the use of ADM in rhinoplasty. A literature search was conducted on PubMed, Prospero, DynaMed, DARE, EMBASE and COCHRANE databases. (Registry: CRD42023428019). A total of 462 patients from 15 studies were included, the mean (range) age was 30 (12-65) years, with a female-to-male ratio of 2:1. The most common indications for ADM were for cosmetic (35%, n = 163) and functional rhinoplasty (5%, n = 24). The most common type of ADM used was Alloderm (46%, n = 211). The most common indication for ADM was dorsal nasal augmentation (68%, n = 314). Eleven patients (2%) required revision surgery. The pooled success of ADM in rhinoplasty was 96% (95% CI 94 to 99, p = 0.93; I2 = 0%). 2% of patients developed postoperative complications and no statistically significant difference was seen in complications or success rates when comparing the different types of ADM. ADM in rhinoplasty was associated with fewer complications and re-operation rates, and similar if not less resorption compared to traditional autografts. Therefore, it can be a viable alternative to current autologous grafts in rhinoplasty surgery.

Novel "Z" Technique to Overcome Warping of Costal Cartilage

BACKGROUND

Dorsal augmentation with costal cartilage is generally used for aesthetic rhinoplasty. However, the tendency of costal cartilage to warp may jeopardize the aesthetic outcome.

OBJECTIVES

The aim of this study was to describe a new "Z" technique to overcome the warping of costal cartilage after implantation and to evaluate the efficacy of this technique in vitro.

METHODS

A total of 31 pairs of porcine costal cartilage grafts (40 mm × 10 mm × 5 mm) were obtained and kept in Dulbecco's Modified Eagle Medium (Sigma-Aldrich, St. Louis, MO) to maintain cell viability. Paired grafts were obtained and randomly allocated for preparation by the accordion technique and the "Z" technique. Standardized photographs (obtained immediately after operation and at 4 weeks) were used for warping analysis. Biomechanical testing was performed to measure the graft's capacity to resist deformation by an external force.

RESULTS

Cell viability of the grafts at 4 weeks was comparably good in the accordion group and the Z group (61.88% ± 4.47% vs 67.48% ± 7.03%, P = 0.55). Warping angle was comparable between the 2 groups (P > 0.01). The capacity to resist external force was significantly better in the Z group; the force needed to cause deformation was 3.98 ± 1.04 N in the Z group vs 1.61 ± 0.47 N in the accordion group in lateral view (P < 0.0001), and 1.33 ± 0.41 N vs 0.96 ± 0.24 N, respectively, in frontal view (P = 0.0013).

CONCLUSIONS

The "Z" technique appears to be a simple and effective method to minimize the tendency of costal cartilage to warp after implantation.

The Promise of Regenerative Medicine in the Reconstruction of Auricular Cartilage Deformities

There are many physiologic and psychologic challenges associated with ear cartilage deformities which are incredibly distasteful to patients, particularly children. The development of regenerative medicine (RM) sciences has opened up a new window for the reconstruction of auricular cartilage because it allows the creation of a structure similar to the auricular in appearance and function. As part of this review, we discuss the role that each RM tool, including tissue engineering, cells, and biomolecules, plays in developing engineered auricular tissue. In previous studies, it was shown that the simultaneous use of natural and synthetic biomaterials as well as three-dimensional printing techniques could improve the biological and mechanical properties of this tissue. Another critical issue is using stem cells and differentiated cartilage cells to produce tissue-specific cellular structures and extracellular matrix. Also, the importance of choosing a suitable animal model in terms of handling and care facilities, physiologic similarities to humans, and breed uniformity in the preclinical assessments have been highlighted. Then, the clinical trials registered on the clinicaltrials.gov website, and the commercialized product, called AuriNovo, have been comprehensively explained. Overall, it is important to provide engineered auricular cartilage structures with acceptable safety and efficacy compared with standard methods, autologous cartilage transplantation, and prosthetic reconstruction in RM.

Fabrication of shape-designable cartilage from human induced pluripotent stem cell-derived chondroprogenitors using a cell self-aggregation technique

With the advancement of tissue engineering technologies, implantable materials have been developed for use in facial plastic surgery, including auriculoplasty and rhinoplasty. Tissue-engineered cartilage comprising only cells and cell-produced extracellular matrix is considered valuable as there is no need to consider problems associated with scaffold absorption or immune responses commonly related to conventional artificial materials. However, it is exceedingly difficult to produce large-sized complex shapes of cartilage without the use of scaffolds. In this study, we describe the production of shape-designable cartilage using a novel cell self-aggregation technique (CAT) and chondroprogenitor cells derived from human induced pluripotent stem cells as the source. The method described does not require special equipment such as bio-3D printers, and the produced tissue can be induced into well-matured cartilage with abundant cartilage matrixin vitro. Using CAT, we were able to generate cartilage in the form of rings or tubes with adjustable inner diameter and curvature, over a range of several centimeters, without the use of scaffolds. Thein vitrofabrication of shape-designable cartilage using CAT is a promising development in facial plastic surgery.

The Ninth and Tenth Costal Cartilages Are Available and Safe Options for Rhinoplasty: A Cadaveric Anatomical Study

SUMMARY

Some practitioners prefer the ninth costal cartilage for autogenous rhinoplasty, but few anatomical studies focus on tapering shape and harvesting safety regarding pneumothorax risk. Therefore, the authors studied the size and related anatomy of the ninth and tenth costal cartilages. Twelve fresh cadavers (24 ribs) were studied. The authors measured the length, width, and thickness of the ninth and tenth costal cartilages at the osteochondral junction (OCJ), midpoint, and tip. To evaluate safety during harvesting, the authors measured the thickness of the transversus abdominis muscle beneath the costal cartilage. The mean lengths of the ninth and tenth cartilages were 99.1 ± 25.0 and 60.6 ± 22.5 mm, respectively. The ninth cartilage was 11.8 ± 2.6, 9.0 ± 2.4, and 2.5 ± 0.5 mm wide, and the tenth cartilage was 9.9 ± 2.0, 7.1 ± 2.0, and 2.7 ± 0.5 mm wide at the OCJ, midpoint, and tip, respectively. The ninth cartilage was 8.4 ± 2.0, 6.4 ± 1.5, and 2.4 ± 0.6 mm thick, and the tenth cartilage was 7.0 ± 2.2, 5.1 ± 1.7, and 2.3 ± 0.5 mm thick at each point. For the transversus abdominis muscle, the thickness was 2.1 ± 0.9, 3.7 ± 1.0, and 4.5 ± 1.3 mm at the ninth cartilage and 1.9 ± 0.5, 2.9 ± 1.1, and 3.7 ± 1.4 mm at the tenth cartilage at each point. The size of the cartilage was sufficient for autogenous rhinoplasty. The transversus abdominis muscle provides thickness for safe harvesting. Furthermore, if this muscle is breached during cartilage harvest, the abdominal cavity is exposed, but the pleural cavity is not. Consequently, there is a very low risk of pneumothorax at this level.

A reinforced framework construction technique using unilateral auricular cartilage in Asian rhinoplasty to prevent long-term nasal tip drooping

BACKGROUND

Enhancing nasal tip projection is an important objective in Asian rhinoplasty. Nasal tip enhancement using auricular cartilage is simple and suitable for Asian patients. However, the long-term retraction problem of the auricular framework still needs to be solved for optimal results.

OBJECTIVES

The authors propose a modified auricular cartilage framework construction technique that provides stronger long-term support to the nasal tip and columellar base.

METHODS

Eighty-one patients underwent augmentation rhinoplasty between January 2016 and December 2019. The cymba and cavum conchae were harvested from one ear in all cases. The cymba concha was carved and folded to form a caudal septal extension graft (CSEG). The cavum concha was divided into an integrated cap/shield graft and a columella base graft. The columella base graft was diced into particles in size of 1 mm3, and inserted into the gap between CSEG, anterior nasal spine, and the medial crus to strengthen the foundation. The nasal profile was analyzed before the operation and at least 12 months after the operation. The patient satisfaction score was assessed 12 months after surgery.

RESULTS

Patients were followed up for 12-36 months. The nasal tip projection from both the lateral and basal views was significantly improved. The columella-labial angle was increased from 83.15° (6.20°) to 96.50° (7.40°) (p < 0.05). The nostril tip proportion increased from 0.83 (0.14) to 1.17(0.16) (p < 0.01). A stable long-term outcome was achieved.

CONCLUSIONS

With the modified framework construction technique, long-term nasal tip drooping can be prevented. This method can be a practical choice for Asian patients seeking augmentation rhinoplasty.

Ultrasound-guided Serratus Anterior Plane Block, Along with Improved Parasternal Block, is Superior to Serratus Anterior Plane Block Alone in Relieving Pain for Rhinoplasty with Autologous Costal Cartilage

BACKGROUND

Rhinoplasty with autologous costal cartilage (ACC) is followed by severe pain in the chest. Ultrasound-guided (USG) serratus anterior plane block (SAPB), in combination with parasternal block (PSB), was earlier reported to be highly efficacious in relieving pain associated with thoracic anterior lateral surgery. However, it is unclear whether it is effective for pain relief after ACC harvest.

METHODS

Sixty-four patients, aged 18 to 60, who received rhinoplasty with ACC, were randomly separated into a SAPB+PSB or SAPB group. The analyzed parameters of both groups included the rest and coughing numerical rating scale (NRS) pain scores of the chest and the NRS pain scores of the nose at postoperative 2, 4, 8, 12, 24, and 48 hours, oral rescue analgesic usage, side effect incidence and patient satisfaction, etc. RESULTS: Thirty patients per group were recruited for analysis. The rest and coughing NRS scores of the chest and the NRS scores of the nose at postoperative 2, 4, 8, 12 h were lower in the SAPB+PSB group, compared to the SAPB group (all P < 0.05). However, these scores were comparable between the two groups at postoperative 24 and 48 h (all P > 0.05). Additionally, relative to the SAPB group, the oral rescue analgesic usage was drastically lower (P < 0.05), the postoperative nausea and vomiting (PONV) incidence was diminished (P < 0.05), and the patient satisfaction was markedly higher (P < 0.001) in the SAPB+PSB group.

CONCLUSION

USG-SAPB, in combination with improved PSB, is superior to SAPB alone in relieving pain after ACC harvest in rhinoplasty.

LEVEL OF EVIDENCE II

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 .

Autologous Costal Cartilage With Expanded Polytetrafluorethylene (ePTFE) Implants for the Treatment of Nasal Deformity After Unilateral Cleft Lip Repair

OBJECTIVE

To repair and reconstruct the secondary nasal deformity after unilateral cleft lip repair, we used autologous costal cartilage and expanded polytetrafluorethylene (ePTFE) to get a better nasal shape.

METHOD

Nineteen patients with nasal deformity after unilateral cleft lip repair were treated from July 2018 to July 2021. During the operation, autologous costal cartilage was carved and formed and then implanted into the nasal tip and nasal columella, while the back of the nose was raised with ePTFE.

RESULT

Nineteen cases were followed up for 6 to 30 months. No transplanted cartilage and swelling were exposed or discharged. The appearance was good, and the patients were satisfied.

CONCLUSION

Autologous costal cartilage combined with ePTFE is an ideal treatment for nasal deformity after cleft lip repair.

Complications associated with costal cartilage harvest in pediatric laryngotracheal reconstruction

Objective

We aimed to determine the rate of complications associated with autologous costal cartilage graft harvest for pediatric laryngotracheal reconstruction (LTR). Secondarily, we sought to identify risk factors associated with the harvest of autologous costal cartilage, as well as evaluate management strategies.

Data Sources

An electronic database search of Ovid MEDLINE, Ovid EMBASE, and PubMed was completed for articles pertaining to complications in autologous costal cartilage harvest for pediatric LTR.

Review Methods

This systematic review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. The study characteristics, operative information, and patient demographics were collected. The data concerning postoperative complications, risk factors, and management strategies were collected and analyzed for patterns.

Results

A total of 31 manuscripts representing 745 patients were included for analysis. The reported donor site complications included pneumothorax (n = 13, 1.74%), pleural tear (n = 5, 0.67%), infection (n = 8, 1.07%), and scar-related problems (n = 2, 0.26%). There were no reported cases of seroma, persistent pain, or chest wall deformity. Only five studies discussed the management of donor site complications, with intervention in 11 (39.28%) patients including chest tube drainage and steroid injection.

Conclusion

There is significant variability in the literature regarding complication rates in autologous costal cartilage harvest for pediatric LTR. The incidence of major postoperative complications is low and supports the use of autologous costal cartilage as graft material for pediatric LTR.

Level of Evidence

NA.

Complications Associated with Autologous Costal Cartilage Used in Rhinoplasty: An Updated Meta-Analysis

OBJECTIVE

To estimate the complications using autologous costal cartilage as grafts in rhinoplasty objectively and systematically with newly published literature.

METHODS

The literature was searched systematically; included studies were published between July of 1990 and April of 2020. Meta-analysis was performed using a random-effects model.

RESULTS

Twenty studies involving 1648 patients were included for meta-analysis. The pooled rates of complications were 3.05% of warping (95% CI 1.36-5.19%), 1.2% of resorption (95% CI 0.26-2.56%), 1.45% of infection (95% CI 0.34-3.06%), and 1.53% of contour irregularity (95% CI 0.53-2.88%). The revision rate was 2.25% (95% CI 0.96-3.9%). Regarding of donor-site morbidities, the rate of hypertrophic chest scar was 2.08% (95% CI 0.31-4.83%), and the rate of pneumothorax was 0% (95% CI 0-0.46%). The pooled rates of complications were 9.06% (95% CI 6.13-12.43%) at the recipient site when complications at the recipient site did not include revision surgery, 1.47% (95% CI 0.17-3.56%) at the donor site, and 15.13% (95%CI 11.03-19.69%) overall. The recipient-site adverse event rate was 12.44% (95% CI 8.98-16.33%).

CONCLUSIONS

Warping was found the most common complication after rhinoplasty with autologous costal cartilage. Revision after rhinoplasty using autologous costal cartilage was increased in these years. Donor-site complications increased the complication rate after rhinoplasty using autologous rib cartilage by 22%.

LEVEL OF EVIDENCE III

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.

Optimizing the Use of Autografts, Allografts, and Alloplastic Materials in Rhinoplasty

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Understand the autologous graft options available to the rhinoplasty surgeon, including septal cartilage, auricular cartilage, costal cartilage, and bone. 2. Understand the autograft and allograft options available to the rhinoplasty surgeon, including cadaveric costal cartilage, silicone, Medpor, and Gore-Tex. 3. Identify the ideal situations to use each of these implant materials. 4. Understand the advantages and disadvantages of the different autografts, allografts, and implants in rhinoplasty.

SUMMARY

This review focuses on the graft options available to the modern rhinoplasty surgeon. Autologous options are varied in the quality of cartilage harvested and the morbidity of the donor site. In addition, surgeons should understand the allograft options should autologous grafting be unfeasible or undesirable. New technological advances in processing of allograft cartilage makes this an attractive secondary option.

Rhinoplasty with Simultaneous Autologous Full-Face Fat Transfer for Asian Facial Contouring Balance: A Retrospective Study

BACKGROUND

The aesthetic facial contouring procedures have gained an increasing popularity in the Asian population. Nevertheless, currently, there are few specific literature assessments and studies on the outcomes of rhinoplasty combined with full-face fat graft contouring. To conduct an objective evaluation of the efficacy of Asian rhinoplasty combined with autologous facial fat transfer in terms of 3-dimensional measurement and patient-reported outcomes.

METHODS

Patients who underwent rhinoplasty combined with full-face fat transfer for facial contouring between January 2016 and July 2019 were recruited in the study. The preoperative and postoperative clinical variables and 3-dimensional measurement of patients were also collected. The satisfaction outcome of surgeons and patients was assessed.

RESULTS

Twenty patients completed rhinoplasty with full-face fat transfer. The average postoperative follow-up was 10.2 months (range 6-24 months). The nasal length, and the nasal protrusion rate were significantly increased (p < 0.05) after surgery, and the median number of nasolabial angles decreased from 106° to 101°, which was closer to the aesthetic standard of 90°-100°. The topographical projection images of whole face indicated that the volume of frontal, temporal, inner cheek and chin regions were increased obviously. All cases received satisfaction outcome based on surgeons' satisfaction scale, ROE scale, FACE-Q overall facial satisfaction scale, and FACE-Q Rhinoplasty scale. Additionally, no patients had intraoperative or postoperative complications.

CONCLUSIONS

Rhinoplasty combined with full-face fat transfer is a reliable and effective method of augmenting and contouring the facial convexity in the Asian populations.

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 .

A Modified Large-Cap Graft in East Asian Revision Rhinoplasty

BACKGROUND

Reconstructing a well-defined nasal tip is a big challenge for East Asian patients, especially with nasal tip irregularities or short noses in revision rhinoplasty. This study aims to report our experience with a modified large-cap graft for improving the contour of the nasal tip in revision rhinoplasty.

METHODS

A retrospective review was conducted for 91 patients (81 females, 10 males; mean age, 26.8 ± 6.7 years) who underwent revision rhinoplasty with a modified large-cap graft. The rhinoplasty outcome evaluation (ROE) was used for investigating patient satisfaction. The aesthetic outcomes were assessed by preoperative and postoperative photographs by two blinded plastic surgeons using the Independent Rhinoplasty Outcome Score.

RESULTS

Most patients reported satisfactory aesthetic outcomes with overall ROE score increasing from preoperative 11.66 ± 3.98 to postoperative 17.30 ± 5.03 (p < 0.001). The doctors' evaluations on the improved contour of the nose rendered an overall score of 3.77 ± 0.42. The complication rate was 3.3% (pleural tear, 1.1%; hypertrophic scar, 2.2%) at the donor site, and 7.7% at the recipient site (warping, 3.3%; extrusion, 1.1%; deviation, 2.2%; infection, 1.1%). No other complications were observed during follow-up.

CONCLUSIONS

Large-cap graft may be safe and efficient for reconstructing contour of the nasal tip in revision rhinoplasty for East Asian patients.

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 .

Complications of the nasal dorsum reconstruction using autologous or alloplastic grafts: evidence from systematic review and meta-analysis

INTRODUCTION

Augmentation rhinoplasty depends mainly on intact stable bony and cartilaginous parts. Many trials have used different materials as a graft to perform the operation and support the nose. Debate exists whether alloplastic or autogenic grafts are more appropriate. Common available alloplastic grafts include silicone, medpor, and gore-tex. Autogenic grafts are usually derived from costal cartilages. Warping, infection, and hypertrophic scars are the main complications of the procedure. Yet no subgroup analysis has been performed to investigate the effect of different risk factors.

OBJECTIVE

To investigate the effect of different types of grafts and the association of the income level of the country on surgery complications.

METHODS

A comprehensive literature search of articles was conducted in PubMed, Cochrane Library, Web of Science, and SCOPUS databases through October 2019. We included articles that used autologous or alloplastic grafts in nasal dorsum reconstruction surgery. We performed subgroup analysis according to the type of graft used, region, and income level of the country. A meta-regression analysis model was carried out from the period of 1999-2018, to study the incidence of these complications over time.

RESULTS

The overall complication rate was 7.1%, which was higher in the alloplastic group (7.8%) than the autogenic group (6.9%). The most common complications were secondary surgery for re-correction (4.1%), infection (2.1%), warping (1.6%), and hypertrophic scars (1.6%). All outcomes were homogeneous (I2 < 50%).

CONCLUSION

Patients with autogenic grafts are less liable to develop complications than their peers reconstructed with alloplastic grafts. Moreover, Asian patients are less susceptible to overall rhinoplasty complications. Attention should be noted for low-income countries in which surgical complications are more prone to occur.

Current Practices in Dorsal Augmentation Rhinoplasty

BACKGROUND

Dorsal augmentation rhinoplasty addresses the aesthetic and functional impairments caused by a deficient nasal dorsum. Augmentation rhinoplasty can be performed using a variety of different surgical techniques and grafting materials that all have distinct advantages and disadvantages.

METHODS

Grafting materials have unique characteristics, uses, and safety profiles. A detailed overview of various grafting materials and their uses, risks, and benefits is provided.

RESULTS

Autologous grafting materials include septal cartilage, auricular cartilage, and costal cartilage. These donor sites can provide various amounts of en bloc or diced cartilage. Alternatively, bone may be used when strong structural stability is required, and soft tissue may be used to fill mild to moderate defects. Homologous grafts (e.g., irradiated and nonirradiated rib) and acellular dermal matrices are alternatives to autologous graft with many similar advantages and no need for an additional surgical site. Lastly, alloplastic implants may be successfully used for dorsal augmentation if both patient and surgeon understand their associated risks.

CONCLUSION

To perform successful dorsal augmentation, surgeons should be familiar with the wide variety of operative approaches and augmentation materials that are currently available and understand their risks, benefits, and uses.

The diagnostic accuracy of hand-held ultrasonography in evaluation of costal cartilage calcification for grafting in rhinoplasty: A cadaveric study

BACKGROUND

Autologous costal cartilage graft (ACC) is considered a gold standard in complex rhinoplasty. Costal cartilage calcification remains a problematic issue, causing not only difficulties during the harvesting, carving, and fixation procedures but also worsening the long-term outcome with resorption.

PURPOSE

This study aims to establish diagnostic accuracy of hand-held ultrasonography in not only detecting the degree and pattern of costal cartilage calcification but also assessing its ability to predict the volume of the harvestable cartilage graft.

METHODS

The study was performed on 50 fresh cadavers with an age range between 17 and 80 years (mean 53.4 ± 16.2 years). An ultrasonographic examination of the costal cartilage of 5th, 6th, and 7th ribs of both hemithoraces was performed. The presence of calcification of the cartilages and the pattern, length, width, cross-sectional area, and depth of calcification were observed and recorded. These results were compared against direct visualization and measurement via surgical dissection.

RESULTS

Hand-held ultrasonography has a sensitivity of 94% and a specificity of 96% in detecting calcification with 96% positive predictive value and 93% negative predictive value. The positive likelihood ratio was 20.81 and the negative likelihood ratio was 0.06. Overall, the modality has demonstrated the ability to determine dimensions of the costal cartilage to within millimeters. The pattern of calcification was also correctly predicted in all 300 specimens.

CONCLUSION

Hand-held ultrasonography is an affordable and accessible choice of demonstrating the presence and pattern of calcification as well as the general dimensions of the harvestable rib cartilage.

Prevalence of complications associated with polymer-based alloplastic materials in nasal dorsal augmentation: a systematic review and meta-analysis

BACKGROUND

Various techniques with different grafts and implants have been proposed to establish a smooth and symmetric nasal dorsum with adequate function. Broadly, two categories of materials have been used in this regard: alloplastic implant materials and autograft materials. The aim of these meta-analyses is to explore the incidence of complications after dorsum augmentation surgery using alloplastic materials.

MATERIALS AND METHODS

After duplication removal 491 papers remained that title and abstract were assessed for eligibility. Regarding the study type, 27 observational studies were included, 21 retrospective and 6 prospective case series. A total of 3803 cases were enrolled in this systematic review and meta-analysis.

RESULT

Twenty-seven articles reported on complications and outcomes of dorsal augmentation rhinoplasty with synthetic materials. In a random-effects model, the weighted mean percentage was 2.75% (95% CI 1.61 to 4.17%). the weighted mean percentage were 1.91% (95% CI 0.77 to 3.54%), 0.72% (95% CI 0.316 to 1.31%), and 0.78% (95% CI 0.43 to 1.24%) respectively.

CONCLUSION

The widely used alloplasts were expanded polytetrafluoroethylene (ePTFE), high-density polyethylene, and silicone. The total rates for complications, infection, deviation, irregularity, hematoma, extrusion, and overcorrection were 2.75%, 1.91%, 0.72%, 0.70%, 0.78%, and 0.49%, respectively. The revision rate, based on the random effects model, was 6.40% with 95%CI (3.84 to 9.57).

TRIAL REGISTRATION

This meta-analysis was registered at the International Prospective Register of Systematic Reviews (PROSPERO, registration number CRD42020209644 ).

The Use of Autologous and Cadaveric Grafts in Rhinoplasty: A Survey Study

BACKGROUND

Both autologous and cadaveric grafts are often used during rhinoplasty to create volume and provide support. Despite discussion in the literature comparing the efficacy, cost-effectiveness, and complication rates between grafting options, it remains unclear which is the superior choice when considering availability, donor site morbidity, and cost. There is a little description of the current use of these materials amongst facial plastic surgeons.

METHODS

A 12 question survey was created, and IRB approval was obtained. The survey was distributed to practicing members of the AAFPRS via their membership listserv.

RESULTS

178 respondents completed the survey for an overall response rate of 17.5%. The most common rhinoplasty graft types used by respondents were autologous septal cartilage (96.6%), autologous auricular grafts (93.8%), autologous rib graft (ARG) (75.8%), and cadaveric rib graft (CRG) (56.7%). Patient comorbidities and performing more than 50 rhinoplasties per year were positively correlated with use of CRG grafts and concerns about complications and cost were negatively correlated.

CONCLUSIONS

While autologous septal and auricular cartilage remain the most common graft choices amongst surveyed facial plastic surgeons, a majority utilize cadaveric rib grafts in their practice. Patient comorbidities, surgery volume, concerns about graft complications, and cost were the chief factors associated with use of cadaveric grafts amongst survey respondents.

LEVEL OF EVIDENCE V

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 .

Crushed Septal Cartilage-Covered Diced Cartilage Glue (CCDG) Graft: A Hybrid Technique of Crushed Septal Cartilage

BACKGROUND

Diced cartilage glue (DG) grafts have been widely used in dorsal augmentation but can induce dorsal irregularities. The authors evaluated the postoperative feasibility of a crushed septal cartilage-covered diced cartilage glue (CCDG) graft.

METHODS

The medical records of 38 patients who underwent dorsal augmentation rhinoplasty with an open approach were retrospectively reviewed. DG graft was used in 18 patients (47.4%), and CCDG graft was used in 20 patients (52.6%). Surgical outcomes were assessed by comparing anthropometric data on facial photographs and satisfaction questionnaires on aesthetic outcomes and palpable irregularities on nasal dorsum before and after surgery.

RESULTS

Both groups showed successful aesthetic outcomes. Dorsal height, radix height, and tip projection were all increased postoperatively in both groups. Tip rotation did not significantly increase (p > 0.05). Both groups showed similar outcomes in terms of aesthetic satisfaction but a significant difference in palpable irregularity. CCDG graft group showed significantly better (p = 0.04) satisfaction with dorsal irregularities (4.15 ± 0.75) than the DG graft group (3.56 ± 0.92). CCDG graft group also showed significantly better mean values (p = 0.048) in the degree of irregularity by two surgeons (3.85 ± 0.65) than the DG graft group (3.25 ± 0.97). No patient had significant complaints about irregular dorsum, and none of them underwent a revision rhinoplasty.

CONCLUSION

CCDG graft can be a complementary option for avoiding postoperative irregular dorsum complications.

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 .

Cost Utility Analysis of Costal Cartilage Autografts and Human Cadaveric Allografts in Rhinoplasty

BACKGROUND

Human cadaveric allograft (HCA) and costal cartilage autograft (CCA) have been described for reconstruction during rhinoplasty. Neither are ideal due to infection, resorption, and donor site morbidity. The clear superiority of 1 graft over the other has not yet been demonstrated. This study assesses comparative costs associated with current grafting materials to better explore the cost ceiling for a theoretical tissue engineered implant.

MATERIALS AND METHODS

A cost utility analysis was performed. Initial procedure costs include physician fees (CPT 30420), hospital outpatient prospective payments, ambulatory surgical center payments, and fees for the following: rib graft (CPT 20910), hospital observation, and DRG (155) for inpatient admission. Additional costs for revision procedure, included the following fees: physician (CPT 30345), rib graft, hospital outpatient prospective payment, and ambulatory surgical center payments. Total costs under each scenario were calculated with and without the revision procedure. Comparison of total costs for each potential outcome to the estimated health utility value allowed for comparison across rhinoplasty subgroups.

RESULTS

The mean cost of primary outpatient rhinoplasty using HCA and CCA were $8075 and $8342 respectively. Revision outpatient rhinoplasty averaged $7447 and increased to $8228 if costal cartilage harvest was required. Hospital admission increased the cost of primary rhinoplasty with CCA to $8609 for observational admission and to $13653 for 1 day inpatient admission. Revision CCA rhinoplasty with an inpatient admission complicated by pneumothorax increased costs to $21 099.

CONCLUSION

Cost of rhinoplasty without hospitalization was similar between HCA and CCA and this cost represents the lower limit of a practical cost for an engineered graft. Considering complications such as need for revision or for admission after CCA due to surgical morbidity, the upper limit of cost for an engineered implant would approximately double.

Enhanced cellular migration and prolonged chondrogenic differentiation in decellularized cartilage scaffolds under dynamic culture conditions

Lesions of aural, nasal and tracheal cartilage are frequently reconstructed by complex surgeries which are based on harvesting autologous cartilage from other locations such as the rib. Cartilage tissue engineering (CTE) is regarded as a promising alternative to attain vital cartilage. Nevertheless, CTE with nearly natural properties poses a significant challenge to research due to the complex reciprocal interactions between cells and extracellular matrix which have to be imitated and which are still not fully understood. Thus, we used a custom-made glass bioreactor to enhance cell migration into decellularized porcine cartilage scaffolds (DECM) and mimic physiological conditions. The DECM seeded with human nasal chondrocytes (HPCH) were cultured in the glass reactor for 6 weeks and examined by histological and immunohistochemical staining, biochemical analyses and real time-PCR at 14, 28 and 42 days. The migration depth and the number of migrated cells were quantified by computational analysis. Compared to the static cultivation, the dynamic culture (DC) fostered migration of HPCH into deeper tissue layers. Furthermore, cultivation in the bioreactor enhanced differentiation of the cells during the first 14 days, but differentiation diminished in the course of further cultivation. We consider the DC in the presented bioreactor as a promising tool to facilitate CTE and to help to better understand the complex physiological processes during cartilage regeneration. Maintaining differentiation of chondrocytes and improving cellular migration by further optimizing culture conditions is an important prerequisite for future clinical application.

Fabrication and evaluation of an optimized xenogenic decellularized costal cartilage graft: preclinical studies of a novel biocompatible prosthesis for rhinoplasty

On account of the poor biocompatibility of synthetic prosthesis, millions of rhinoplasty recipients have been forced to choose autologous costal cartilage as grafts, which suffer from limited availability, morbidity at the donor site and prolonged operation time. Here, as a promising alternative to autologous costal cartilage, we developed a novel xenogeneic costal cartilage and explored its feasibility as a rhinoplasty graft for the first time. Adopting an improved decellularization protocol, in which the ionic detergent was substituted by trypsin, the resulting decellularized graft was confirmed to preserve more structural components and better mechanics, and eliminate cellular components effectively. The in vitro and in vivo compatibility experiments demonstrated that the decellularized graft showed excellent biocompatibility and biosecurity. Additionally, the functionality assessment of rhinoplasty was performed in a rabbit model, and the condition of grafts after implantation was comprehensively evaluated. The optimized graft exhibited better capacity to reduce the degradation rate and maintain the morphology, in comparison to the decellularized costal cartilage prepared by conventional protocol. These findings indicate that this optimized graft derived from decellularized xenogeneic costal cartilage provides a new prospective for future investigations of rhinoplasty prosthesis and has great potential for clinical application.

Long-Term Complications from Diced Cartilage in Rhinoplasty: A Meta-analysis

Objective: To analyze the incidences of long-term complications and revision surgery associated with diced cartilage grafts in dorsal augmentation rhinoplasty. Methods: The PubMed, MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases were searched for clinical studies on the use of diced cartilage for dorsal augmentation published. A meta-analysis was conducted to pool the estimated rates of infection, overcorrection, visible irregularity, absorption, and revision surgery. Result: A total of 14 studies involving 2380 patients were included in the systematic review. The combined rates were 11.5% for overall complications and 5.3% for revision surgery. The rates of the most frequently reported complications were 4.5% for infection, 5.3% for visible irregularity, 0.7% for overcorrection, and 0.5% for absorption. There was no significant difference in the rates of visible irregularity (p = 0.23) and revision surgery (p = 0.71) among the wrapped diced cartilage, glued diced cartilage, and free diced cartilage groups. Conclusion: This meta-analysis presents the first comprehensive and quantitative report of long-term complications associated with diced cartilage in dorsal augmentation rhinoplasty. Infection and visible irregularity were the most frequently reported complications. The rates of irregularity and revision surgery were not correlated with the diced cartilage packing methods.

Harvesting Split Costal Cartilage Graft in Revision Rhinoplasty Without Disturbing the Costal Integrity

BACKGROUND

Graft use is inevitable in some primary and secondary rhinoplasty cases with cartilage or bone deficiency. Although rib graft is one of the best graft sources, it has several disadvantages. The purpose of this study is to minimize the risks of using rib grafts.

MATERIAL AND METHODS

Between 2018 and 2020, a total of 21 patients aged between 25 and 55 have undergone revision rhinoplasty under general anesthesia with a split cartilage graft of central origin. A 3-4-mm-thick bridge was left at the superior and inferior edges of the donor area, and the graft was harvested from the central region without disrupting the costal integrity. A special retractor was placed between the perichondrium and the rib at the posterior of the costa to prevent damage to the pleura while cutting the rib. The previously marked grafts were cut in the donor area and harvested ready for use. The harvested grafts were used as spreader, strut, alar rim and nasal valve grafts.

RESULTS

None of the patients had complications due to rib graft harvesting. After the operation, pain in the donor region and analgesic requirement of these patients were less compared to the patients with full-layer grafts.

CONCLUSIONS

The grafts taken from the center of the costa without breaking its integrity seem quite suitable for revision rhinoplasty surgeries. This technique prevents various morbidities and enables patients to have a more comfortable postoperative period.

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 .

Grafting in Modern Rhinoplasty

Rhinoplasty is considered one of the most technically difficult surgical procedures because of the limited access and requirement for three-dimensional visual perception and manipulation. Grafting is an essential part of primary and secondary rhinoplasties and forms the foundation for a successful functional and aesthetic outcome. Septal cartilage is the most commonly used grafting material, although many reliable alternatives exist. No randomized clinical trials have been conducted comparing graft materials and techniques for specific indications. In this review, the authors discuss the most common grafting materials and configurations used in the modern rhinoplasty.

Complications in Facial Esthetic Surgery

Esthetic surgery continues to become increasingly popular both in the United States and globally. Facial esthetic procedures in particular account for a large proportion of procedures performed. This increase in popularity will inevitably result in the number of potential complications associated with these procedures. In this review, the authors describe common complications encountered with frequently performed cosmetic facial procedures and their associated management. This article is meant as a general overview and introduction to potential complications surgeons may encounter, interested readers are encouraged to further review comprehensive subspecialty literature for more detailed discussion.

Multicenter Pilot Study to Assess a Biphasic Calcium Phosphate Implant for Functional and Aesthetic Septorhinoplasty

Importance: A validated biomaterial would have several medical advantages in septorhinoplasties requiring a large-volume graft such as avoiding donor site morbidity, making ambulatory surgery possible, and reducing surgical costs. Objective: To assess the safety and efficacy of a ceramic to treat saddle and crooked noses. The main endpoint was the biocompatibility of the implant. The secondary endpoint was its functional and aesthetic efficacy. Design, Setting, and Participants: The nasal septum (NASEPT) study is a pilot multicenter noncomparative prospective phase IIa clinical trial. The biomaterial tested was a biphasic calcium phosphate implant composed of 75% hydroxyapatite and 25% beta tri calcium phosphate. This versatile material can be used to replace septal skeleton when it is absent or nonusable. We included 25 patients with a multifractured osseous and cartilaginous framework after several traumas or surgeries. The implant placement technique was identical to an extracorporeal septoplasty through the external approach. Main Outcomes and Measures: The primary endpoint was the occurrence of expected adverse and severe adverse events. The secondary endpoints were clinical functional and aesthetic results and histological microscopic modifications. Results: Any extrusion, infection, pain, and epistaxis were observed. All implants were placed in a sagittal, straight, and solid position without extralobular depression. Comparisons between pre- and postoperative symptoms showed that nasal comfort (p < 10^-4) and quality of life (p < 10^-4) were dramatically improved in all patients. The nasolabial angle (p = 0.047) and the columellar projection (p = 0.024) were improved after surgery. Histological data showed little submucosal inflammation at 6 months with well-differentiated epithelium. The mean follow-up was 23 months: three patients underwent revision surgery for functional or aesthetic details and four implants were removed (16%) owing to a foreign body reaction between 17 and 74 months. Conclusion and Relevance: The NASEPT implant meets functional and aesthetic requirements in complex septorhinoplasties but its long-term biocompatibility needs to be improved. It could potentially avoid donor site morbidity.

Rib cartilage in Asian rhinoplasty: new trends

PURPOSE OF REVIEW

Costal cartilage has many advantages over other grafting materials because of its large quantity and high biocompatibility. As a result, it has been considered as a good option for Asian rhinoplasty. However, costal cartilage is difficult to use and is associated with a high complication rate. To avoid the disadvantages and complications of costal cartilage graft, several techniques have been proposed in the literature. This review addresses the conventional uses of costal cartilage in Asian rhinoplasty and recent updates.

RECENT FINDINGS

Different techniques have been reported for Asian rhinoplasty using costal cartilage. Solid-block costal cartilage and diced cartilage with or without wrapping materials are widely used for dorsal augmentation. Many different grafting techniques for the tip and septal reconstruction have been reported by numerous surgeons. When using costal cartilage graft, surgeons should pay attention to both graft complications, such as warping or infection, and donor-site morbidity. Several strategies have recently been developed to avoid these complications.

SUMMARY

This article summarises grafting options for Asian rhinoplasty using costal cartilage and possible complications. This information may assist with proper selection of appropriate techniques for harvesting, carving and grafting costal cartilage.

Septorhinoplasty for Destructed Septal L-Strut in Patients with Previously Applied Porous High-Density Polyethylene Implants (Medpor®)

BACKGROUND

Porous high-density polyethylene implants (Medpor^®) have been extensively used for septal extension grafts in Asian rhinoplasty. However, studies on the long-term complications associated with Medpor^® have not been reported. Therefore, the purpose of this study was to evaluate the long-term complications of septal extension grafts using Medpor^® and present a reconstructive strategy for destructed septal L-struts.

METHODS

We conducted a 12-year retrospective medical chart review of 428 patients who visited our center for septorhinoplasty. Among 428 patients, 43 patients had Medpor^® for septal extension grafts previously applied at other clinics. The quadrangular cartilage was devoid or destructed in the area where Medpor^® was previously applied. Therefore, all patients underwent secondary septorhinoplasty using autogenous cartilage grafts. Patient outcome was assessed to evaluate satisfaction, hardness of nasal tip, functional nasal obstruction symptom evaluation (NOSE) scores, and pain scores. Anthropometric analyses were carried out with patients' photographs. Postoperative complications were also evaluated.

RESULTS

After septal L-strut reconstruction, 87% of patients were satisfied with their aesthetic results. Hardness of nasal tip, NOSE scores, and pain scores also improved after reconstruction. Anthropometric analyses demonstrated that increased nasal length and decreased columellar-labial angle were achieved in patients with short nose deformities. No postoperative complications related to the reconstruction were recorded for any patient.

CONCLUSIONS

The devastated destruction of nasal support lines was found after the use of Medpor^® for septorhinoplasty. Therefore, the use of Medpor^® should be reduced. Autogenous cartilage grafts are the last resort for reconstruction of destructed septal L-struts.

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 .

Dermatologic Biopsy of Silicone Nasal Implant and Revision Rhinoplasty in the Asian Patient, A Cautionary Report

Care provided to the Asian rhinoplasty patient may be multidisciplinary at times, including not only plastic surgeons, but also other health care professionals. It is crucial that all physicians caring for these patients practice complete awareness of the patient's prior operations and details of materials used in order to optimize results and avoid potentially devastating complications. These complications include but are not limited to implant infection and extrusion. Here the authors describe one such case report, discussing dermatologic biopsy of a silicone implant of the nasal tip and dorsum and subsequent revision rhinoplasty with implant removal and costochondral graft placement.

Rhinoplasty outcomes and trends

PURPOSE OF REVIEW

This article reviewed studies that support the use of implants for nasal valve surgery and augmentation rhinoplasty.

RECENT FINDINGS

For nasal valve collapse, there is a trend for rhinoplasty surgeons to use Monarch nasal implant, absorbable valve implant and titanium butterfly implant rather than traditional cartilaginous grafts. For augmentation rhinoplasty, it is still a gold standard to use autologous cartilage. However, alloplastic implants are still very popular for Asian rhinoplasty. A combination of implant materials for augmentation rhinoplasty can improve outcomes while minimizing complications.

SUMMARY

Application of implants and newer techniques in nasal valve surgery and augmentation rhinoplasty are important to enhance the outcome in rhinoplasty.

Extent of Inflammation and Foreign Body Reaction to Porous Polyethylene In Vitro and In Vivo

BACKGROUND/AIM

High-density porous polyethylene (PP) offers possibilities for reconstruction in craniofacial surgery. The purpose of this study was to evaluate the extent of inflammation and foreign body reactions to PP in vitro and in vivo.

MATERIALS AND METHODS

Cell attachment, proliferation and expression of inflammatory cytokines were assessed using murine macrophages (RAW 264.7) on two different PP materials in vitro. In vivo, Balb/c mice received PP implants at their dorsum. After sacrifice, samples were analyzed histologically and real-time PCR was used to assess expression of inflammatory cytokines.

RESULTS

Cells showed a significantly decreased proliferation (p<0.001) after 48 h and a significantly increased expression of TNF-α (p<0.05) at 24, 48 and 72 h. All animals showed foreign body cell reactions and signs of chronic inflammation. Expression of all but one of the investigated cytokines dropped to non-significant levels after an initial increase.

CONCLUSION

Application of porous polyethylene can cause local chronic inflammatory reactions. Although clinical application seems to be immunologically safe, indication and risks should be evaluated carefully when using PP implants.