Porous high-density polyethylene in facial reconstruction and revision rhinoplasty: a prospective cohort study

Submucosal Trans-Septal Suturing Technique After a Septal Extension Graft with Porous High-Density Polyethylene: A Technical Report

BACKGROUND

Porous high-density polyethylene (pHDPE) is an alternative material for a septal extension graft (SEG) in oriental rhinoplasty when autologous cartilage is limited. Although nasal packing (NP) and trans-septal suturing (TSS) techniques are routine procedures to obviate the dead space after septoplasty, they are associated with certain discomforts and complications.

OBJECTIVE

To investigate the application of a submucosal trans-septal suturing (STSS) technique after SEG with pHDPE.

METHODS

A prospective study was conducted on 60 female participants who underwent SEG with pHDPE. The participants were randomly divided into the NP group and STSS group. The extra surgical duration of NP and STSS, pain, nasal obstruction, and sleeping disturbance as well as postoperative complications were recorded and compared between groups.

RESULTS

No significant difference was found between group NP and group STSS in terms of mean age. The mean extra surgical duration of group STSS was significantly longer than group NP. There were significant higher pains of group NP at 24 hours and 48 hours postoperatively, compared with group STSS. The NP group also experienced significantly more nasal obstruction and sleep disturbance within 48h postoperatively compared to the STSS group. There was one infection in each group, minor bleeding in two NP patients, and one STSS patient. There was no major bleeding, hematoma, graft exposure, or septal perforation in both groups.

CONCLUSION

Although STSS needs a longer extra surgical duration than NP, it significantly improves the patient's postoperative comfort with a faster return to normal respiration compared to NP.

LEVEL OF EVIDENCE I

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Application of a Single T-Shaped Porous High-Density Polyethylene in Oriental Nasal Tip-Plasty

Porous high-density polyethylene (pHDPE) is an alternative material for septal extension grafts. This study investigated the clinical application of a single T-shaped pHDPE graft combined with auricular cartilage in oriental nasal tip-plasty. A retrospective analysis was conducted of 66 patients who underwent septal extension graft with a T-shaped pHDPE and auricular cartilage graft from December 2018 to November 2021. All patients were female from 19 to 51 years old (average: 28.9 years). Patients were followed up for 5 to 40 months with an average of 23.8 months. The postoperative nasal length (39.8±3.7 mm) was significantly improved (35.6±5.7 mm preoperatively, P <0.0001) with the tip projection increasing from 23.9±2.3 mm preoperatively to 25.3±2.4 mm postoperatively ( P =0.0005). There was a significant difference in the nasolabial angle (96.8±14.1 degrees preoperatively versus 101.8±7.2 degrees postoperatively, P =0.0105) but no significant change in the nasofrontal angle (143.3±9.5 degrees preoperatively versus 143.7±5.5 degrees postoperatively, P =0.7546), with an improved tip projection achieved in 93.9% of patients. One patient had an abscess in the nasal septum and a tip graft was performed using auricular cartilage in another patient because of an insufficient postoperative tip projection. There was a slight tip deviation in 2 patients, 1 case of a deviated nasal tip was corrected with a pHDPE sheet graft, while the other was left intact. Two patients had excess cartilaginous graft protruding to the nasal cavity that did not affect nasal ventilation and the shape of the nasal tip was relatively good, so the prominent cartilaginous graft was not addressed. In conclusion, this technique not only improved the bulbous nasal tip, lengthened the short nose, and increase the tip projection, but also prevented absorption of the existing septal cartilage and reduced infection or extrusion of the pHDPE.

Study on Size Estimation of Prosthesis in Rhinoplasty Based on Mechanical Test and Analysis

Rhinoplasty is a common plastic surgery. The determination of prosthesis size for rhinoplasty has long been dependent on the surgeon's experience. Some of the patients suffered from complications after the surgery. In this paper, we present a method for estimating the size of prosthesis in rhinoplasty. A nasal tension tester is designed and implemented. On the basis of the mechanical theory of Hyperelastic Materials, an algorithm for inverse calculation of material parameters is proposed; On the basis of the material parameters, an algorithm for estimating the safety range of nasal stretch is established. The nasal tension tester can obtain the nasal tension data without harming the subject. Our results show that different subjects generally have different nasal skin elasticity and tolerance to skin stretch. Therefore, the selection of prosthesis size for rhinoplasty should not be generalized, but should be tested and calculated separately for each subject. The results of this study are helpful for doctors to quantitatively understand the skin condition of the subject 's nose and the safe range of nasal stretch, based on which the determination of prosthesis size can be made for rhinoplasty.

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.

Transumbilical Single-incision Laparoscopic Surgery for Harvesting Rib and Costal Cartilage

The study aimed to introduce a rib and costal cartilage harvesting surgery by transumbilical single-incision laparoscopy and evaluate its efficiency and safety.

Biocompatible implant mimicking cartilage: A new horizon for reconstructive facial field

Cartilage is avascular with limited to no regenerative capacity, so its loss could be a challenge for reconstructive surgery. Current treatment options for damaged cartilage are also limited. In this aspect there is a tremendous need to develop an ideal cartilage-mimicking biomaterial that could repair maxillofacial defects. Considering this fact in this study we have prepared twelve silicone-based materials (using Silicone 40, 60, and 80) reinforced with hydroxyapatite, tri-calcium phosphate, and titanium dioxide which itself has proven their efficacy in several studies and able to complement the shortcomings of using silicones. Among the mechanical properties (Young's modulus, tensile strength, percent elongation, and hardness), hardness of Silicone-40 showed similarities with goat ear (P > .05). Silicone peaks have been detected in FTIR. Both AFM morphology and SEM images of the samples confirmed more roughed surfaces. All the materials were nonhemolytic in hemocompatibility tests, but among the twelve materials S2, S3, S5, and S6 showed the least hemolysis. For all tested bacterial strains, adherence was lower on each material than that grown on the plain industrial silicone material which was used as a positive control. S2, S3, S5, and S6 samples were selected as the best based on mechanical characterizations, surface characterizations, in vitro hemocompatibility tests and bacterial adherence activity. So, outcomes of this present study would be promising when developing ideal cartilage-mimicking biocomposites and their emerging applications to treat maxillofacial defects due to cartilage damage.

Biological coating with platelet-rich plasma and adipose tissue-derived microvascular fragments improves the vascularization, biocompatibility and tissue incorporation of porous polyethylene

Porous polyethylene (pPE) is a commonly used biomaterial in craniofacial reconstructive surgery. However, implant failure due to insufficient vascularization represents a major issue. To overcome this problem, we herein introduce an effective strategy to improve the vascularization and incorporation of pPE. Adipose tissue-derived microvascular fragments (MVF) from transgenic green fluorescent protein (GFP)⁺ mice were suspended in platelet-rich plasma (PRP) for the coating of pPE. PRP/MVF-coated pPE as well as PRP-coated and uncoated controls were subsequently implanted into the dorsal skinfold chamber and the flanks of GFP^- wild-type mice to analyze their in vivo performance throughout 2, 4 and 8 weeks by means of intravital fluorescence microscopy, histology and immunohistochemistry. The GFP⁺/GFP^- cross-over design allowed the identification of GFP⁺ MVF within the implants. Shortly after implantation, they rapidly reassembled into new blood-perfused microvascular networks, resulting in a significantly accelerated vascularization of PRP/MVF-coated pPE when compared to both controls. The overall numbers of rolling and adherent leukocytes within the microcirculation as well as macrophages, multi-nucleated giant cells and mast cells around the implants did not differ between the three groups. However, in contrast to uncoated controls, PRP/MVF-coated and PRP-coated pPE promoted pro-angiogenic M2 macrophage polarization at the implantation site. These findings demonstrate that PRP/MVF-coating represents a highly effective strategy to enhance the vascularization, biocompatibility and tissue incorporation of pPE. STATEMENT OF SIGNIFICANCE: The clinical in vivo performance of implanted biomaterials is crucially dependent on their adequate incorporation into the body. To achieve this, we herein introduce an effective biological coating strategy. Our results demonstrate that coating with PRP and MVF accelerates and enhances the vascularization, biocompatibility and tissue incorporation of porous polyethylene. Because this type of biological coating is easily applicable on any type of biomaterial, our approach may rapidly be translated into clinical practice to improve the outcome of various regenerative approaches.

A triple-layered closing technique using the recti muscles to augment implant coverage in eye enucleation after maxillofacial radiotherapy: A case report

Eye enucleation (EE) of a previously irradiated orbit can lead to difficult wound closure due to the soft tissues fibrosis such as Tenon's capsule and conjunctiva. We, here, report a technique modification for EE surgery after facial radiotherapy that may decrease implant exposure by using recti muscles native tissue to reinforce the anterior implant coverage. A 71-year-old African male presented in 2003 a right orbital extranodal marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) type. He was treated with chemotherapy followed by whole orbital radiotherapy. His right vision remained impaired due to phtisis bulbi secondary to facial radiotherapy. By 2017, he developed right painful phthisis bulbi. Radiological systemic staging did not reveal any recurrence or metastasis. Because of the history of neoplasia, the right eye had to be enucleated. Due to tissue fibrosis secondary to radiotherapy, we took care to preserve as much conjunctiva and Tenon as possible. EE was performed under general anesthesia. EE consisted of a standard procedure with a modified triple-layered closing technique. The four recti muscles were attached with 5-0 Vicryl to the anterior part of the implant by passing the needle through the tunnels and tying the suture. The horizontal muscles were spread with a forceps to cover the lateral and medial part of the implant. The vertical muscles were spread with a forceps to cover the superior and the inferior part of the implant. Finally the edges of the recti muscles were sutured to each other with 5-0 Vicryl to create a muscle layer. Tenon's capsule and conjunctiva were closed separately, using horizontal interrupted 6-0 Vicryl sutures. One year after surgery, wound closure was complete with no sign of extrusion. The triple-layered closing technique using the recti muscles in EE represents a potentially viable alternative to augment implant coverage in case of Tenon and conjunctival fibrosis secondary to facial radiotherapy.

A Review of Current Regenerative Medicine Strategies that Utilize Nanotechnology to Treat Cartilage Damage

BACKGROUND

Cartilage is an important tissue found in a variety of anatomical locations. Damage to cartilage is particularly detrimental, owing to its intrinsically poor healing capacity. Current reconstructive options for cartilage repair are limited, and alternative approaches are required. Biomaterial science and Tissue engineering are multidisciplinary areas of research that integrate biological and engineering principles for the purpose of restoring premorbid tissue function. Biomaterial science traditionally focuses on the replacement of diseased or damaged tissue with implants. Conversely, tissue engineering utilizes porous biomimetic scaffolds, containing cells and bioactive molecules, to regenerate functional tissue. However, both paradigms feature several disadvantages. Faced with the increasing clinical burden of cartilage defects, attention has shifted towards the incorporation of Nanotechnology into these areas of regenerative medicine.

METHODS

Searches were conducted on Pubmed using the terms "cartilage", "reconstruction", "nanotechnology", "nanomaterials", "tissue engineering" and "biomaterials". Abstracts were examined to identify articles of relevance, and further papers were obtained from the citations within.

RESULTS

The content of 96 articles was ultimately reviewed. The literature yielded no studies that have progressed beyond in vitro and in vivo experimentation. Several limitations to the use of nanomaterials to reconstruct damaged cartilage were identified in both the tissue engineering and biomaterial fields.

CONCLUSION

Nanomaterials have unique physicochemical properties that interact with biological systems in novel ways, potentially opening new avenues for the advancement of constructs used to repair cartilage. However, research into these technologies is in its infancy, and clinical translation remains elusive.

Use of porous high-density polyethylene grafts in open rhinoplasty: no infectious complication seen in spreader and dorsal grafts

OBJECTIVE

The aim of this study is to use porous high-density polyethylene grafts (Medpor) in open rhinoplasty and then assess complication rate and aesthetic outcomes.

METHODS

In a prospective cohort study, we performed open rhinoplasty and employed Medpor as rhinoplasty grafts. Then we compared their complication rate.

RESULTS

In a total of 64 patients, 84 Medpor grafts--8 dorsal grafts, 23 strut grafts, 8 rim grafts, 5 button grafts and 10 spreader grafts--were utilized. Moreover, 5septal perforation repairs with Medpor were performed. The complication rates were 5.3% in dorsal graft (complication in dorsal graft was only movement of implant), 21.7% in strut graft and 25.0% in rim graft. No complication was seen in spreader and button grafts. All 5septal perforation repairs were successfully performed with the same rhinoplasty approach.

CONCLUSION

Medpor can be used as dorsal and spreader graft in reconstruction of severe nose deformity with lowest complication rate and without infectious complication and extrusion.