Asian Septorhinoplasty: Conundrums and Solutions

© Springer Nature Singapore Pte Ltd. 2021

E.-S. Dhong, M.-W. NaAsian Septorhinoplastyhttps://doi.org/10.1007/978-981-16-0542-0_1

1. The Longevity of Alloplastic Implants

Eun-Sang Dhong¹   and Min-Wha Na²

(1)

Department of Plastic and Reconstructive Surgery, Guro Hospital, College of Medicine, Korea University, Seoul, Korea (Republic of)

(2)

Yerom Plastic Surgery Clinic, Seoul, Korea (Republic of)

Eun-Sang Dhong (Corresponding author)

Email: prsdhong@korea.ac.kr

Pearls

Bone resorption under the alloplastic implant is determined by (1) the implant’s hardness, (2) the retention period, (3) implant location, and (4) the tension of the soft tissue envelope.

Not only the tissue defects caused by the removal of the capsule, but the concavity induced by bone resorption should be considered when determining the dorsal on laying volume of the secondary surgery.

The rhinion weakened by bone resorption makes the spreader graft very difficult and requires a long length.

Unstable rhinion can induce saddle nose deformity after septorhinoplasty using autologous grafts.

When correcting the mild hump nose, it is better to carve the implant than the bony dorsum by cutting the implants under part rather than resecting the bony dorsum.

Putting an implant after medial and lateral osteotomies causes instability, which can cause long-term implant deviation.

Dorsal implanting is not recommended after osteotomy. However, if necessary, the modification of leaving a broad platform in the rhinion area should be considered.

Minor differences between the bony axis and the septal axis may be emphasized when the dorsum is projected, so care should be taken when implanting.

In the secondary operation to solve complications caused by an implant, autografts should resolve the dorsum.

1.1 Bony Resorption Under Alloplastic Implants

Apart from the primary and secondary operation, there is no substitute as convenient and easy as the alloplastic implant in Asian rhinoplasty. As a way to increase the bony dorsum and cartilaginous dorsum at once, the surgeon only needs to pay attention to the tip plasty. Many Asian rhinoplasty surgeons’ presentations at conferences focus exclusively on tip surgery and tend to overlook dorsum. The bony dorsum is rigid and immobile, but the cartilaginous dorsum provides a large amount of mobility. The mechanical effect of the rigid alloplastic implant on the underlying tissue is very different at each location. There are a myriad of alloplastic implants, but clinically, for dorsal projection, it is limited to three materials: boat-shaped Silicone, Gore-tex, and Alloderm. There are so many other hybrid products that are too diverse, so the author will not discuss them in this chapter. In general, it is widely used in this order, and among them, the use of Silicone solves the low nasion, which is the most used in Korea.

Bone resorption under the silicone implant applied to chin augmentation or malar augmentation has been reported. Methyl methacrylate and silicone are known to cause thinning of the skin on the top with bone resorption on the bottom. The bone under the polyfluoroethylene may also be resorbed [1]. It should be noted that both silicone and Gore-Tex, which are most commonly used in Asian rhinoplasty, may result in resorption of the underlying bone.

The factors determining bone resorption degree are implant hardness, retention period, and implant location. Here, the pressure of the soft tissue envelope and the external physical force of the facial mimetic muscle play an essential role.

Implantation through subperiosteal dissection of the nasal bone may decrease the implant’s mobility but also a factor that promotes bone resorption.

Concavity induced by removing capsules around the implant and bone resorption causes a vast amount of dorsal skin depression in secondary rhinoplasty. When preparing the autograft, surgeons should prepare a larger dorsal onlaying graft volume than the actual implant volume (Fig. 1.1).

Fig. 1.1

Skin flap remaining after removing the silicone capsule. It created a massive concavity with bone resorption. (a) Lateral view, (b) frontal view

The extensive bony resorption of the most critical rhinion can be observed in a long-lasting implant (Fig. 1.2).

Fig. 1.2

Bone resorption under silicone implant: axial CT scan. Bone resorption with bone erosion

1.2 Silicone Implant over Osteotomized Nasal Bone

Dorsal to tip projection is sometimes required after humpectomy and correcting a deviated nose. The method of using implants after the humpectomy is not recommended. Also, there is no evidence that it is safe to insert an alloplastic implant in the dorsum after the left or right lateral osteotomy [2]. The alloplastic implant tends to tilt to one side when inserted on the nasal bone in the patient who underwent medial and lateral osteotomy. This phenomenon is found in almost all patients who visited my clinic for the reoperation.

If you flatten the rhinion under the implant, as shown in the following picture, you can find that the rhinion is already weakened, and the bottom is severely destroyed. Also, the osteotomized lateral wall cannot be a safe platform for the dorsal implant (Fig. 1.3).

Fig. 1.3

Rhinion: destroyed by a silicone implant. (a) A rhinion destroyed by a 5 mm-thick silicone implant. (b) The base on the right side is pressing the nasal mucosa. This patient is presumed to be performed medial and lateral osteotomy

The weakened rhinion acts as an obstacle to reconstruction after implant removal.

However, in many Asian rhinoplasties, there is a tendency to correct the discrepancy by using an alloplastic implant after bony dorsum reduction. Even now, rather than excessive humpectomy, efforts should be made to fit the profile by carving the implant’s undersurface.

The destruction of the rhinion makes the spreader graft very difficult. When applying the spreader graft, the length must be long enough; otherwise, anterior (high) septal instability may occur after surgery.

When correcting the hump nose, the author focuses on the projection of the cartilaginous dorsum rather than reducing the hump excessively.

Destruction of rhinion and nasal mucosa by the implant is believed to cause late-onset inflammation in the long term (Chap. 2).

Unstable rhinion can induce saddle nose deformity after septorhinoplasty using autologous tissue. So the instability can later cause inverted V deformity.

Do not use dorsal implants to cover any open roof deformity after humpectomy.

Medial oblique osteotomy is advantageous for implant support during corrective osteotomies. The Nasal bone can act as a platform on which an implant can be placed (Fig. 1.4). In the lateral osteotomy with medial osteotomy, a greenstick osteotomy is advantageous for the nasal pyramid’s stability (Fig. 1.5).

Fig. 1.4

Medial oblique osteotomy can preserve more bones for the stable implant platform. (a) Paramedian osteotomy. (b) Medial oblique osteotomy

Fig. 1.5

Design of the greenstick fracture between medial oblique osteotomy and lateral low-high osteotomy

The nasal platform above the rhinion can be preserved using the medial oblique osteotomy line for support.

The lateral bone instability is often generated; the implant is sinking to the weak side. It can cause long-term implant deviation (Fig. 1.6).

Fig. 1.6

Silicone implant dislocated to the left side with malunion of the lateral nasal bone

It is difficult to find an implant that is located exactly in the midline on the nasal bone. Therefore, bone rasping may be more advantageous than osteotomy, but it cannot be applied in all cases. Ensuring a stable platform for implant placement is the most crucial key when projecting while reducing the wide nasal bone width. It is better to apply autograft to the dorsum when osteotome is accompanied.

1.3 Implant Deviation

Longer Implant than the Pocket

The most significant cause of the deviation is the tension in the implant’s longitudinal direction, generated by a longer implant than the pocket size. In this case, lateral capsulotomy is attempted as a closed technique, but this method is not very helpful unless the implant’s length is shortened. Any means to reduce tension should be used. With the introduction of very soft silicone, implant deviation occurs even with less longitudinal pressure. Make sure to make enough soft tissue envelopes and use implants that are not too long. Note that implant mobility occurs when excessive dissection is performed.

Bony Axis Vs. Septal Axis

No matter how low the nose, the bony axis, and the axis of the cartilaginous dorsum are often different. If this is overlooked, the implant tilts according to the slope of the platform. Light axis discrepancy can be camouflaged with an appropriate implant-carving, but deviations are often seen again after swelling disappears.

Even patients with very low nasion can find that the cartilaginous dorsum is directed to one side from the rhinion. In this case, although silicone was inserted, there may be a discrepancy between the upper one-third and lower two-third postoperatively, resulting in cosmetic dissatisfaction (Fig. 1.7).

Fig. 1.7

Silicone deviation. (a) Very low nasion with axis discrepancy between the bony axis and the axis of the cartilaginous dorsum. (b) Frontal view. (c) Distinct deviation by the dorsal highlights

On the other hand, when the deviation of the septum is resolved with a spreader graft, a dorsal autograft yields a more stable result (Fig. 1.8).

Fig. 1.8

Correction of deviation by autograft only. (a) Preoperative view. (b) After the spreader graft: correction of the high septum. (c) Dorsal highlight was focused on the Lt. side spreader graft. (d) Postoperative view

However, applying the spreader graft under an implant to correct the deviation is a waste of cartilage. Although the spreader graft is functional and invisible, if covered by the dorsal implant, applying septal cartilage underneath the implant is ineffective. A dorsal implant may camouflage the deviation.

When the spreader graft is adopted, an autologous material is recommended at the dorsum. After the ULC and the septum are separated, an alloplastic implant is not recommended on it. Micromucosal damage after complete dissection between ULC from anterior septum can cause late-onset inflammation.

There are many cases in augmenting very low nasion, in which alloplastic implants have to be used. In this situation, dissect the pocket more widely.

Prepare a platform as flat as possible with a rasping. Bring the implant to the midline by sculpting the undersurface asymmetrically.

It is advantageous not to perform septal dissection when implants must be used on the dorsum. In other words, without dissecting the ULC and anterior septum, the axis deviation of the lower two-third can be corrected by connecting the implant to the tip by appropriate suture rather than the spreader graft.

Minor differences between the bony axis and the septal axis may be emphasized when the dorsum is projected, so care should be taken when applying a dorsal implant.

Implant-Dependent Dorsum

In Asian rhinoplasties, the techniques have been evolved on the premise that alloplastic materials augment the dorsum. The main methods have focused on tip projection and extension.

The severe deviation cannot achieve a straight dorsal line without proper septal adjustment. Furthermore, implant-dependent dorsum does not apply to secondary rhinoplasty with soft tissue problems.

As the septum goes, the implant goes.

Secondary Operation Using Silicone Implant (Re-insertion)

In secondary operation, it is unavoidable to remove the silicone and re-insert the silicone implant. If the nasion is too low, or if the patient refuses to apply autograft, the last option is to use an alloplastic implant again.

Soft tissue can be applied to the anterior surface of the silicone implant as a barrier. Placing a superficial mastoid fascia [3] on the anterior side implant fades the demarcation and supports the thin anterior skin (Fig. 1.9).

Fig. 1.9

The anterior surface of the silicone implant was covered with flattened superficial mastoid fascia

The indications of applying anterior soft tissue are:

1.

After removing all capsules, if the anterior skin envelope remains very thin.

2.

Surgery to correct implant demarcation.

3.

In secondary operation, when the silicone must be re-inserted after removing the silicone.

1.4 Clinical Features of Complications

Silicone Implants

Capsule: Contracture

Silicone inevitably forms a capsule. If five silicone surgeries are performed, five different capsules are formed. If the capsules are not removed, those are not resorbed naturally (Fig. 1.10). The scar band of myofibroblast or fibroblast formed around the capsule is consistent with the inflammatory reaction. Some capsules are healthy and very thin; these can be used as soft tissues in secondary surgery. Nonhealthy capsules that are made up of very thick scars cause contractures that should be removed. In Chap. 2, the author will discuss the late-onset inflammation of nonhealthy capsules.

Fig. 1.10

Multilayers of silicone capsules were removed from a secondary surgery

Calcification

Calcification is a characteristic feature on the surface of old silicone. It can be easily diagnosed on an X-ray, and in older cases, it may cause skin lesions.

It is essential to remove both the anterior and posterior capsules. When removing the anterior capsule, be careful of skin necrosis (Fig. 1.11).

Fig. 1.11

Calcification of old silicone implant. (a) Preoperative view; skin thinning with venous engorgement. (b) Silicone and the capsule; the anterior surface of the silicone was covered with stone-like calcification. (c) Skin problem: the thin skin is in danger of necrosis, hyperbaric O² treatment is recommended. (d) Postoperative view

Demarcation, Transparency

In patients with too low nasion, demarcation around the implant can be found. Also, in thin-skinned patients, the silicone is seen through the sunlight, making it appear transparent. The above method of applying the soft tissue to the anterior surface effectively controls demarcation and transparency (Fig. 1.12).

Fig. 1.12

Transparent silicone implant in thin skin

Gore-tex

Since Gore-tex has micropore, it has a high infection rate along with Medpor among alloplastic implants. In a proportion of 3% or more, implant removal is required due to infection. Surgeons might think that there is no contracture because it doesn’t make a capsule, but the bigger problem is the use of silicone and Gore-tex alternately due to multiple surgeries.

Contracture occurs even in Gore-tex inserted into a capsule made of silicone, and the late-onset inflammation that happens in this situation shows a very complex clinical feature.

Shrinkage and Demarcation

Shrinkage and demarcation of the implant is a phenomenon peculiar to Gore-tex that occurs when the micropore is reduced. It is characterized by a very hard leather-like degeneration when removed. Since it does not make a capsule, it is sometimes more difficult to remove. It should be noted that there is no such opportunity as the capsule can be used as some soft tissue in the case of a patient who has undergone multiple surgeries using a silicone implant. When removing Gore-tex, it also should be noted that the dorsal skin on the affected area is very thin. Such thin skin takes a very long time to regain its elasticity and return to its original shape (Fig. 1.13). Along with demarcation, many patients complain of unknown pain due to this thin skin (Fig. 1.14).

Fig. 1.13

Demarcated Gore-tex. (a) Preoperative quarter view, (b) postoperative view

Fig. 1.14

A patient who suffered from unknown nasal pain. (a) Preoperative view, (b) Pain disappeared after removing dorsal Gore-tex and replaced with autologous dermis graft

Demarcation around the implant, accompanied by shrinkage, is also commonly found in silicone implants with healthy capsules (Fig. 1.15). In other words, demarcation around the implant may occur in both silicone and Gore-tex. Even too superficially inserted dermofat graft may be demarcated, so care should be taken to handle the thick dermis margin.

Fig. 1.15

Demarcated silicone implant with contracture (a, b) preoperative view, (c, d) postoperative view

IHCC (Irradiated Homologous Cartilage)

Resorption: Fracture

The resorption was found to be the most problematic in the long-term follow-up of IHCC. The resorption rate of autologous costal cartilage is 3%, and that of IHCC is 30% [4]. There had been a problem with fracture-resorption, so the author no longer uses it [5]. Conclusively IHCC is not free from surgical site infection (SSI) and late-onset inflammation (LOI) other than resorption and fracture.

When used