Advancements in the Application of Artificial Materials in Nasal Surgery

Abstract

With the ongoing advancement of nasal endoscopic surgical techniques, rhinologists are increasingly tasked with addressing not only nasal sinus lesions but also exploring transnasal approaches for managing lesions involving the eyes and skull base. The complex anatomy of the nose, adjacent to the skull base superiorly and the medial orbital walls bilaterally, supports the use of artificial materials during surgical procedures for repair or reconstruction. Furthermore, artificial materials aid in the regeneration of nasal mucous membranes, promoting healing. This article reviews the selection of artificial materials used in nasal surgery and recent advancements in related research.

Nasal endoscopy technology was introduced to China in the 1980s, initially used primarily for diagnosing nasal diseases. Over time, with advancements in China’s nasal endoscopy technology, its applications have expanded significantly. This evolution now includes various surgical fields involving the nose, eyes, and skull base. Nasal surgery can be categorized into two main types based on its purpose: conventional and reconstructive surgery. Conventional surgery focuses on treating lesions in the nasal cavity and sinuses, while reconstructive surgery is dedicated to repairing and reconstructing the skull base, orbital wall, and adjacent structures through an intranasal approach. In modern practice, materials used in endonasal surgery are mainly classified into 2 groups: autologous and synthetic materials. Autologous materials, such as bone, fat, and fascia, are highly effective in preventing cerebrospinal fluid leakage. However, harvesting these tissues not only prolongs the surgical procedure but also increases the risk of postoperative complications.¹ The intraoperative use of appropriate artificial materials facilitates defect repair, promotes tissue healing, and ensures optimal surgical outcomes while minimizing the damage associated with additional tissue extraction. The use of commonly employed artificial materials in nasal surgery is now being reviewed.

SURGICAL INTERVENTIONS DESIGNED TO RESTORE TISSUE INTEGRITY

Nasal-Skull Base Surgery

The rapid advancement of nasal endoscopic surgical technology has introduced a novel approach for treating skull base lesions. Nasal endoscopes, available in various angles, provide an excellent field of vision during surgery, facilitating exposure of the complex tissue structures at the skull base. Compared with traditional craniotomy, transnasal endoscopic surgery causes less trauma, reduces operation time, and leads to quicker postoperative recovery.² Consequently, an increasing number of rhinologists are addressing skull base space-occupying lesions through the nasal approach. However, intraoperative reconstruction of the skull base is crucial to prevent cerebrospinal fluid leakage, which is essential for ensuring treatment efficacy. While the use of autologous materials for repair supports postoperative vascularization and material integration, extracting these materials inevitably leads to scarring and hematoma formation at the donor site.³ In addition, patients with prior surgeries at the extraction site may not have sufficient material available. Therefore, the use of artificial materials in transnasal skull base surgery is becoming increasingly common.

Injectable hydroxyapatite (HXA) is a widely used bone substitute that provides robust support for defects at the skull base.⁴ Composed of calcium phosphate, HXA forms a cement-like substance when exposed to water or sodium phosphate solution, gradually solidifying after application to the bone defect. This makes HXA straightforward to use during nasal endoscopic skull base repairs.

However, the curing time of HXA is prolonged when it comes into contact with water. Therefore, it is crucial to apply HXA to a completely dry bone surface. Continuous bleeding or cerebrospinal fluid leakage from the surgical wound can further extend the curing time, potentially impacting both the duration of surgery and postoperative outcomes.⁵ In modern rhinology, multilayer repair techniques are predominantly employed to address these challenges. The use of multilayer materials in these repairs helps minimize HXA’s direct contact with fluids, significantly reducing its curing time whenever possible.⁶ Nevertheless, certain unavoidable issues remain with the use of HXA for skull base repair, including an increased risk of postoperative nasal sinus infections.

Polydioxanone sheet (PDS) is an absorbable biomaterial initially used exclusively for nasal septal reconstruction. With advances in surgical techniques, PDS has increasingly been employed for rigid skull base defect repair under nasal endoscopy.⁷ PDS possesses ideal prosthetic material characteristics, including absorbability, stability, and the absence of imaging artifacts.¹ It can be customized to fit the specific defect in both site and size and is delivered nasally through the nasal cavity to the skull base defect under endoscopic guidance. The PDS is trimmed to match the defect’s size and location, ensuring precise delivery. However, due to the pulsatile movement of brain tissue, the PDS may shift, potentially leading to repair failure. To minimize graft movement, surgeons use the PDS wrapping technique, which involves placing a dural graft as a liner before positioning the customized PDS plate on top. The graft edges are folded and sutured to form a PDS wrapping, ensuring optimal postoperative outcomes.⁸

Decellularized dermal allografts (ADM) were initially used in the treatment of burn wounds and dental applications to promote mucosal regeneration and wound healing.⁹ In practice, this technique can also be applied to address minor skull base defects, effectively preventing cerebrospinal fluid leakage.¹⁰ ADM is soft, making it easy to fold and trim, which is particularly advantageous for transnasal manipulation during nasal endoscopy. Due to its retractable nature, ADM should be sized ~30% larger than the leak when used for skull base repair.¹¹ After detecting cerebrospinal fluid leakage intraoperatively via nasal endoscopy, the surrounding mucosa is carefully excised to expose the underlying bone. ADM is then placed over the leak and secured with nasal tamponade. ADM acts as a scaffold for cellular regeneration, promoting cell adhesion, growth, and mucosal epithelialization. It also regulates rapid blood vessel regeneration to support the healing process.¹² However, for larger leaks, ADM alone may not provide sufficient rigid support and may be ineffective. In such cases, ADM is combined with other materials for multilayer repairs, such as nasal septal mucosal flaps, vascularized nasal septal flaps, abdominal fat, or thigh fascia, to achieve optimal results.¹³

Naso-ocular Surgery

The close anatomic relationship between the nose and the eye allows rhinologists to effectively manage diseases in both regions through nasal endoscopy. This includes procedures such as transnasal optic nerve decompression, lacrimal sac-nasal anastomosis, and transnasal orbital tumor resection. Based on the anatomic relationship between the sinonasal complex (OMC) and the orbit, transnasal endoscopic surgery is the preferred approach for treating lesions in the adjacent medial orbital region.¹⁴ Nasal sinus masses, such as mucous cysts of the ethmoid sinus, maxillary sinus carcinoma, intranasal papillomas, and osteoproliferative disorders, including osteofibroblastic syndromes, may encroach on the orbital wall as they progress laterally. Therefore, it is essential for the rhinologist to not only remove the nasal sinus lesion completely but also repair or reconstruct the orbital wall. As a result, an increasing number of artificial materials are being used in nasal and ocular surgeries.

Many autologous and allogeneic materials are used for orbital wall repair and reconstruction. Autologous bone grafts, such as those from the skull, ribs, and iliac bone, are particularly considered for patients requiring postoperative radiotherapy. In these cases, autologous bone grafts are the preferred material.¹⁵ However, using autogenous bone for orbital repair increases collateral damage to the patient, leading to a growing use of artificial materials in clinical practice. Titanium mesh, an allograft, is increasingly employed for orbital floor and rim reconstruction due to its excellent biocompatibility.¹⁶ For patients with maxillary sinus tumors requiring subtotal or total maxillectomy, the postoperative defect is substantial, and conventional titanium mesh alone may be insufficient for orbital wall reconstruction. In such cases, surgeons can integrate 3D printing technology to design titanium patches that precisely match the defect’s contours, ensuring a better fit and repair outcome.¹⁷ The design of titanium mesh also allows connective tissue infiltration, preventing graft displacement.¹⁵ For larger defects, titanium mesh can be combined with autologous materials for orbital wall repair. For example, it can be used with coronal temporal pedicle flaps or free flaps to reconstruct defects from total maxillary resections.¹⁸ Titanium grafts for orbital wall reconstruction have demonstrated superior long-term postoperative outcomes and significantly reduced surgery duration compared with traditional methods using autogenous bone.¹⁹ ADM, known for its biocompatibility, offers a unique combination of flexibility and rigidity, providing effective support for orbital soft tissues, making it suitable for orbital wall repair and reconstruction as well.²⁰

Surgical Repair of the Nasal Septum

Patients with nasal septum perforation often experience symptoms such as nasal dryness, congestion, and recurrent rhinorrhea. Those with anterior septal perforations may also hear a whistling sound during breathing, which can significantly impact their quality of life. Therefore, once a septal perforation is identified, prompt surgical intervention is necessary. In patients with a deviated septum or with a spur of nasal septum, separating the mucosa on both sides of the septum may result in mucosal perforation. Consequently, any septal perforation must be addressed and repaired simultaneously. While autologous tissue remains the preferred choice for septal repair, artificial materials are increasingly used due to the limited availability of suitable cartilage. Common artificial materials for septal repair include polydioxanone (PDS), polycaprolactone (PCL), titanium, and acellular dermal matrix (ADM).

The repair of the nasal septum using PDS has proven to be a safe and effective method. PDS acts as a supportive material for structures such as cartilage while promoting mucosal healing. This technique stabilizes the septal structure and accelerates mucosal epithelialization. In addition, PDS plates degrade spontaneously within the body, aiding chondrocyte regeneration at the perforation site.²¹ The primary goal of repairing nasal septal perforations is to restore the normal physiological functions of the nasal cavity, including heating and humidification. Achieving this requires not only a rigid repair of the septum but also effective reconstruction of the septal mucosa. For larger perforations (>2 cm) with significant mucosal damage, PDS alone is used for repair, though this approach may lead to suboptimal postoperative outcomes. ADM serves as a scaffold for mucosal cell regeneration, enhancing both epithelialization and vascular regeneration. The combination of PDS and ADM in septal perforation repair is expected to yield better results.²² However, the high cost of the acellular dermal matrix (ADM) is a consideration. Polypropylene mesh, primarily used in gynecologic and urological surgeries, can also be employed in nasal septal perforation repair due to its excellent biocompatibility. It provides a scaffold that promotes neovascularization, mucosal growth, and wound healing.²³ However, using polypropylene mesh alone for nasal septum repair increases the risk of complications such as infection, abscess formation, and necrosis. In contrast, combining polypropylene mesh with platelet-rich fibrin (PRF) significantly reduces these risks. PRF, widely used in oral and maxillofacial surgery, has been shown to promote wound healing, vascular regeneration, and new tissue formation.²⁴ Allograft cartilage can also be used in nasal septal perforation repair, similar to autografts. It shares properties such as resistance to infection and deformation and effectively relieves nasal congestion symptoms in patients.²⁵

Reconstruction of Sinus Structures

If a sinus lesion infiltrates the sinus wall, reconstruction of the sinus structure is necessary after excision. Osteoma is one of the most common benign tumors in the sinuses, primarily affecting the frontal sinus. For small, asymptomatic osteomas, dynamic observation with regular follow-up may be appropriate. However, if the osteoma grows and causes symptoms or leads to cranial or ocular complications, surgical intervention should be considered. Surgical options for osteoma treatment include nasal endoscopic techniques, extranasal methods, and combined approaches, with the choice depending on the osteoma’s location and size.²⁶ For patients with large frontal sinus osteomas requiring an extranasal approach, reconstruction of the anterior wall of the frontal sinus is necessary to minimize cosmetic impact. Various materials can be used for this repair, including autologous skulls, titanium mesh, porous polyethylene, and methyl methacrylate.²⁷ Titanium mesh offers rigid support and has a low risk of infection, even when in direct contact with the sinus mucosa, resulting in a very low incidence of postoperative infections.²⁸ In addition, titanium mesh produces minimal artifacts during MRI and CT, making it an ideal material for frontal sinus wall repair.²⁹ With advancements in 3D printing technology, repairing defects in curved maxillofacial bones has become more feasible. The use of 3D-printed custom titanium mesh for nonplanar maxillofacial defect repair can effectively facilitate sinus drainage and reduce postoperative complications.³⁰

GENERAL NASAL SURGERY

Due to the unique anatomy of the nasal sinuses, complete excision of lesions in these cavities may lead to the loss of mucosal coverage over the bone surface. This increases the risk of postoperative complications such as adhesions, stenosis, or even atresia of the sinus openings. ADM provides structural support for the injured mucosa, effectively reducing the time required for postoperative epithelialization.³¹ ADM also minimizes the risk of scar sclerosis and contracture while reducing secretion production. In patients with specific autoimmune diseases, mucosal healing in surgical areas is often delayed, making ADM the preferred option for repairing these challenging wounds.³² To ensure optimal outcomes, it is essential to provide a well-vascularized graft bed for ADM. In addition, nasal tamponade should be applied to exert appropriate pressure, immobilizing the ADM. Maintaining moisture in the operative cavity post-surgery is also crucial to prevent desiccation of the repair membrane.

SUMMARY

With advancements in biotechnology, artificial materials are increasingly used in nasal surgery. Selecting the appropriate material is key to achieving optimal surgical outcomes, as each has distinct advantages and disadvantages. Therefore, the choice of material type, shape, and size should be customized to meet the specific needs of the procedure. In addition, various artificial materials can complement each other, and their combination can significantly enhance surgical outcomes. As the use of artificial materials expands, more patients are expected to benefit from their application.