Introduction:
The most important function of the nose is breathing. If there is any obstruction in the anatomy of the nose, it will affect the airflow and breathing and hence the quality of life. These nasal defects can be corrected by nasal reconstruction surgery using nasal implants. There are several types of nasal implants used for nasal reconstruction.
What Are Nasal Implants?
“Nasal” means “nose,” and “implant” means those materials which are placed inside the body or on the surface of the body to improve body function. So, nasal implants are those devices that are placed inside the nose to improve the functions of the nose.
What Are the Indications of Nasal Implants?
Nasal implants are primarily used for nasal reconstruction. It is done to correct a deformity on the nose. The nasal deformity or nasal defect can occur in the following conditions:
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Trauma.
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Congenital deformities.
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Malignant destruction (in case of cancer or tumor).
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Septal perforations (minute holes in the nasal septum that is the wall between the nostrils).
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Granulomatous diseases (caused by granuloma, which is a minute cluster of tissue, including white blood cells).
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Congenital (since birth) syphilis, leprosy, leishmaniasis (a disease caused by a parasite).
What Are the Contraindications of Nasal Implants?
There are some conditions in which nasal implants cannot be done. They are:
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Active infections.
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Conditions in which additional therapy like serial debridement is required.
In addition, if the patient is on chemotherapy or radiotherapy, nasal reconstruction should be done after the completion of these therapies.
What Are the Characteristics of an Ideal Implant?
Since implants are foreign materials that are placed inside the nose, there are always chances of complications; an ideal material should have the following qualities:
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Biologically inert.
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Infection resistant.
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Noncarcinogenic (which does not cause cancer).
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Nondegradable.
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It should be available widely, cost-effective, easily removable, and modifiable.
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It should be trauma resistant and easy to shape.
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It should be able to provide adequate volume and support and must be non-toxic.
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It should be able to retain its physical properties with time and must not move from its place.
However, finding all these requirements in a single implant is difficult.
What Are Available Types of Nasal Implants?
There are several types of materials used for nasal reconstruction. These materials are:
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Autologous implants (autografts).
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Homologous implants (homografts).
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Alloplastic implants (alloplasts).
What Are Autologous Nasal Implants?
Autologous implants are also called autografts. These are those materials that are taken from the tissues of the same patient. The examples of autologous nasal implants are discussed below:
1. Cartilage -
Below are the sites of cartilage used for nasal reconstruction:
Nasal Septum (Septal Cartilage):
Nasal septal cartilage is derived from the nasal septum. This graft can be easily taken during the surgery from the same surgical site being operated on. The donor site morbidity is minimum here. The only limitation is sometimes the insufficient amount of graft material available in the patient's nasal septum. However, if there is a sufficient amount of septal cartilage graft available in a patient's nasal septum, these grafts are the preferred and best choice for nasal reconstructions.
Concha (Auricular Conchal Cartilage):
These grafts are taken from the ear. These are more flexible and not as rigid as septal cartilage. Because these are located close to the nose and are adequate in quantity as compared to the nasal septum, they can be easily taken for nasal reconstruction. However, undesirable donor site morbidity and irregularities in the cartilage contour are the drawbacks.
Rib (Costal Cartilage):
These grafts are taken from ribs. These are preferred after nasal septum and auricular cartilage when the surgery requires more grafts and the graft quantity from the nasal septum and auricular cartilage is not sufficient.
These grafts are more prone to distort and have remarkable donor site morbidity. In addition, they can cause pain in the donor site (chest), can leave scars and may predispose to conditions like pneumothorax. In older patients, due to the calcification of rib cartilage, these grafts cannot be used.
Advantages of Autografts:
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Biocompatibility is good.
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Do not transmit diseases.
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Low infection rates.
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Low rates of absorption.
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Low rates of rejection by the body.
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Low rates of extrusion.
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The graft-host interactions are favorable.
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Rates of inflammation are low.
Limitations of the Autografts:
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Not readily available.
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Tissue harvest is associated with morbidity.
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However, these autografts are considered gold-standard materials among all the materials available for nasal implantation. All the other materials are measured against autografts.
2. Bone Grafts:
Bone grafts are preferred after cartilage graft. Sites of bone grafts are-
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Calvarium.
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Rib and iliac crest.
Its disadvantages include a lack of flexibility, risk of fracture, visible scarring, and a longer
immobilization period for graft fixation.
3. Soft-tissue Grafts:
The sites of soft -tissues grafts are-
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Fat.
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Fascia.
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Dermis.
Their disadvantage is that they are insufficient in providing adequate structural support.
What Are Homologous Implants (Homografts)?
These are materials taken from donors of the same species. The site of these grafts is irradiated rib cartilage taken from cadavers. They have low rates of infections, provide very good structural support, the host immunogenic response is low, and there is no risk of transmission of diseases associated with these implants.
However, their biggest drawback is that they tend to distort over time.
What Are Alloplastic Implants (Alloplasts)?
These are materials that are entirely synthetic or semi-synthetic in nature and are made up of polymers.
Types of Alloplastic Implants:
1. Silicone Implants:
These are made up of silicon. It is indicated for soft-tissue nasal augmentation. Its limitations include failure to provide structural support. It can cause chronic inflammation as well if not fixed properly in place by tissues surrounding the implant. So, this is how silicone nasal implants can become infected.
2. Meshed Implants:
These implants are made up of synthetic polymers. They serve advantages like being available in customized shapes and sizes. Minimum rates of infection and better stability. The disadvantages include difficulty in removing from the body after the occurrence of host ingrowth.
3. Porous Implants:
These implants provide stability and are easy to remove.
4. Porous High-Density Polyethylene:
These implants are easy to mold into the required shape. It provides structural support and is safe and effective. Bone resorption is also minimum. The disadvantages are rigidity, difficulty to remove, and can cause infection.
5. Expanded-Polytetrafluoroethylene:
These implants are soft and flexible and are used for soft tissue augmentation in the nose. However, it is not used for the structural graft.
Conclusion:
Nasal implants are composed of various materials, either synthetic or natural. All have some advantages and limitations for nasal reconstruction and augmentation surgery to correct nasal defects. To conclude, autologous implants are the best implants of all. However, the choice of the implant to be used in nasal surgery depends upon one’s requirements to obtain maximum benefit after the surgery.
