Otoplasty: surgical correction of lobosity

The abundance of otoplasty techniques described in the literature makes it a unique phenomenon in its field. Since Ely described the technique for correcting prominent ears in 1881, more than 200 operations of this kind have appeared. As with all plastic surgeries, modern conservative and minimalistic approaches dominate in recent research.

Otoplasty is a surgical correction of prominent ears. Similar to rhinoplasty, the path to an optimal result begins with a three-dimensional analysis of the deformity. Surgical correction requires determining the relationship of the components of the auricle to the underlying bone skeleton. Moreover, in order to preserve the natural appearance of the ear, these components - the helix-antihelix, auricle, tragus-antitragus and lobe - must be assessed before surgery and, when performed, set in natural positions for the ear.

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Historical essay

Deformities of the auricle have been the subject of creative analysis for many years. Certain features (such as Darwin's tubercles and flattened auricular margins) have been suggested as predisposing to criminal behavior. The deformity discussed in this chapter is in fact a group of deformities that share the common external appearance of a prominent ear. This may be due to the classic absence of the antihelix, excessive protrusion of the auricle, or a combination of these deformities. Less commonly, the deformity is aggravated by the presence of a twisted or protruding ear lobe.

Techniques for restoring the normal relationship of the auricle to the scalp and underlying mastoid process have been described since the 19th century. The first description of otoplasty was given by Ely, who reduced a prominent ear by performing a through excision of a section of the ear consisting of the anterior skin, cartilage, and posterior skin. Similar techniques were later proposed (Haug, Monks, Joseph, Ballenger, and Ballenger), which used a reduction approach to otoplasty, i.e., removal of skin and cartilage.

In 1910, Luckett rightly considered the absence of the antihelix to be the cause of classic protruding ears. This discovery, in light of the anatomical approach to correction of the defect, allowed him and subsequent authors to develop correct approaches. Early techniques involved cutting the ear cartilage anteriorly and posteriorly from the intended location of the antihelix. Luckett proposed a crescent-shaped excision of the skin and cartilage at the site of the intended antihelix. The remaining edges of the cartilage were then sutured. Becker's technique also included anterior and posterior incisions around the intended antihelix. He then formed a new antihelix with fixing sutures. A further change can be seen in the Converse technique, where the anterior and posterior incisions were followed by suturing the antihelix segment in the form of a tunnel.

The emphasis in modern techniques is on making sure that there are no visible traces of the operation. The goal is to make sure that the edges of the cartilage are not visible, and that the ear is smooth, attractive, and proportionate to the skull. After discussing applied anatomy and embryology, we will highlight the two main approaches to otoplasty - cartilage suturing and cartilage molding - and the many variations of both techniques that have been developed.

Anatomy and Embryology

The outer ear is a cartilaginous structure, with the exception of the earlobe, which does not contain cartilage. This flexible elastic cartilage is covered by skin, which is firmly attached in front and more loosely at the back. The cartilaginous plate has a definite shape and can be described as a combination of ridges and cavities, not completely surrounding the bony external auditory canal.

The normal ear is positioned at an angle of 20-30° to the skull. The distance from the lateral edge of the helix to the skin of the mastoid process is usually 2-2.5 cm. When viewed from above, it is noticeable that the tilt is the result of a combination of the conchomammillary angle of 90° and the concholadian angle of 90°. The average length and width of the male ear are 63.5 and 35.5 mm, respectively. The corresponding sizes in women are 59.0 and 32.5 mm.

Analysis of the normal ear's flexures begins with the helix and antihelix. They begin inferiorly, at the level of the tragus, and diverge superiorly, where they are separated by the scaphoid fossa. Superiorly, the antihelix divides into a smoother, wider superior crus and an inferior crus. Viewed from the front, the helix forms the most lateral deviation of the ear from above and should be just visible behind the antihelix and superior crus.

The cartilage is attached to the skull by three ligaments. The anterior ligament attaches the helix and tragus to the zygomatic process of the temporal bone. The anterior portion of the cartilaginous external auditory canal is devoid of cartilage and is delimited by a ligament that runs from the tragus to the helix.

The ear has external and internal muscles innervated by the seventh cranial nerve. These small muscles are concentrated in specific areas, creating soft tissue thickenings with increased blood supply. These muscles are practically nonfunctional, although some people can wiggle their ears.

Arterial blood supply to the ear. It is carried out mainly from the superficial temporal artery and the posterior auricular artery, although there are several branches from the deep auricular artery. Venous outflow occurs in the superficial temporal and posterior auricular veins. Lymphatic drainage occurs in the parotid and superficial cervical lymph nodes.

Sensory innervation of the external ear is provided by several sources. The temporoauricular branch of the mandibular division of the fifth cranial nerve innervates the anterior margin of the helix and part of the tragus. The remainder of the anterior ear is innervated primarily by the greater auricular nerve, while the posterior surface of the ear receives innervation from the lesser occipital nerve. Small contributions are made by the seventh, ninth, and tenth cranial nerves.

"Tubercles of His" are the six visible projections described by this author that develop in the ear of the 39-day-old embryo. Although His attributed the origin of the first three tubercles to the first branchial arch and the other three to the second branchial arch, subsequent research has challenged this theory. It is now believed that only the tragus can be attributed to the first branchial arch, with the rest of the ear developing from the second branchial arch. This opinion is supported by the fact that the congenital parotid pits and fistulas are located along the anterior and intertragic notches. Since these areas anatomically represent the dividing line between the first and second branchial arches, the anomalies mentioned may originate from the first pharyngeal impression. Most ear deformities are inherited in an autosomal dominant manner. A similar pattern of inheritance is also observed in the parotid pits and appendages.

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Function

The function of the ear in lower animals is well studied. The two established functions are sound localization and protection against water penetration. Protection against water is provided by the opposition of the tragus and antitragus. In humans, these physiological functions have not been confirmed.

Preoperative assessment

Like all facial plastic surgeries, otoplasty requires careful preoperative evaluation and analysis. Each ear must be evaluated individually, as the deformity or deformities present may vary greatly from one side to the other. The ear must be assessed for size, relationship to the scalp, and the relationship between its four components (helix, antihelix, concha, and lobe). Typical measurements recorded during the preoperative examination include:

• The distance between the mastoid process and the helix at the level of its highest point.
• The distance between the mastoid process and the helix at the level of the external auditory canal.
• The distance between the mastoid process and the helix at the level of the lobe.

Additional measurements made by some authors include measuring the distance from the apex of the helical margin to the junction of the superior and inferior crura, as well as the distance from the helical margin to the antihelix.

Preoperative photographs are taken - a frontal view of the entire face, a back view of the entire head, and targeted images of the ear(s) with the head positioned so that the Frankfurt horizontal is parallel to the floor.

The anomaly most often seen in protruding ears is an overgrowth or protrusion of the cartilage of the auricle. Such deformities are not corrected by operations that restore the antihelix. They require interventions in the relationship between the auricle and the compact layer of the mastoid process. Protrusion of the lobe may be the only deformity in an otherwise normal ear. This may be due to an unusual shape of the tail of the helix.

Otoplasty techniques

The typical patient for otoplasty is a child aged 4-5 years who is referred by a pediatrician or parents because of protruding ears. This is the ideal age for correction, as the ear is already fully formed and the child has not yet started school, where he or she may be the subject of ridicule.

In young children, general anesthesia is most often used. In older children and adults, intravenous sedation is preferred. The patient's head is placed on a headrest, and the ears remain uncovered throughout the procedure.

The surgical techniques used to correct protruding ears depend on the preoperative analysis. Often, a protruding auricle is determined as an isolated deformity or in combination with a deformity of the antihelix.

Moving the auricle back

The auricle is returned to its correct anatomical position relative to the mastoid process using sutures, with or without undercutting the lateral margin of its cavity. The traditional technique of retracting the auricle as described by Furnas remains the procedure of choice for protruding auricles. This technique is characterized by wide exposure of the posterior surface of the ear and the periosteum of the mastoid process. Permanent non-absorbable sutures (the author prefers 4-0 Mersilene) are passed through the auricular cartilage and then through the periosteum of the mastoid process in such a way as to fix the auricle posteriorly and medially. The sutures should not be placed too far anteriorly in the periosteum, otherwise the external auditory canal may be affected. Additional correction of the protruding auricle can be achieved by excising a lateral strip of the auricular cartilage. An incision can be made in the lateral aspect of the auricle, using landmarks created with 25-gauge needles dipped in methylene blue. This incision allows the removal of an elliptical portion of the auricular cartilage to allow additional medial displacement of the ear.

An alternative operation on the auricle is described by Spira and Stal. This is the lateral flap technique, where a flap with a lateral base is created from the cartilage of the auricle and sutured posteriorly to the periosteum of the mastoid process. Proponents of this method believe that it reduces the likelihood of deformation of the external auditory canal.

Deformations of the antihelix

The number of operations described to reconstruct the missing antihelix indicates that neither is entirely satisfactory. As otoplasty techniques evolved, two schools emerged. The first, following the teachings of Mustarde, used sutures to reconstruct the antihelix. The second group of operations involved surgical interventions on the cartilage, by incisions, dermabrasion, or grooving. Most modern techniques are a combination of these two approaches, using sutures to fix the final position of the antihelix, but adding methods of reshaping the cartilage to reduce the risk of re-bulging.

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Suture techniques

For most otoplasty techniques, the approach and landmarks are similar. A postauricular incision is made and a wide undercut is made above the perichondrium. The area of the suspected antitragus can be marked by passing 25-gauge injection needles from anterior to posterior, through the skin and cartilage, which is then marked with methylene blue.

The Mustarde procedure involves placing three or four horizontal sutures to create a permanent antihelix. We have found Mersilene 4-0 to be most suitable for this purpose, but many other suture materials have been reported. The technique of suturing is critical to achieving a smooth correction and preventing deformity of the upper ear. The suture is placed through the cartilage and anterior perichondrium, but not through the skin of the anterior ear. If the suture does not include the anterior perichondrium, there is a risk of eversion of the cartilage. If it is placed too far anteriorly, it may include the inner surface of the anterior auricular dermis and cause retraction at the site of suturing.

According to Bull and Mustarde, the sutures should be placed as close together as possible to avoid crimping. However, if they are too close, the cartilage between the sutures may weaken. Also, if the outer portion of the suture is too close to the apex of the ear, a mailbag-type deformity may occur. The authors suggest placing centimeter-long stitches at 2 mm intervals on the distal cartilage. The distance between the distal and proximal punctures is 16 mm. The lowest suture is placed to displace the tail of the curl posteriorly. In some cases, undercutting is performed.

The technical difficulties of the standard Mustarde otoplasty relate to the precision of the sutures. Often the sutures are tightened blindly, with the surgeon determining the degree of tension by observing the folding of the tissues into the antihelix on the outside of the ear. All sutures should be placed before the final tightening. Some authors describe a technique using temporary sutures that are placed anteriorly to secure the shape of the proposed antihelix while the posterior sutures are tightened. Burres described an "anteroposterior" technique in which the pinna is retracted through a posterior incision, but the helical sutures are placed anteriorly, through a series of anterior notches. In another technique, these sutures may be placed externally but sunk into small notches. Since Mustarde's initial work, many additional procedures have been described to correct the tendency of the ear to protrude forward again over time. This is due to several factors. First, incorrect placement of sutures without capturing a sufficient portion of cartilage leads to cutting of the threads and return of the ear to its original position. Second, when the suture does not capture, it is the perichondrium that promotes cutting of the cartilage. Therefore, special care must be taken to ensure their correct placement - the most common factor in repeated displacement of the ear is the springy rigidity of the cartilage. Therefore, various techniques have been proposed to reduce the shape memory of the cartilage. According to physiological principles, the presence of cartilage in the desired position should be facilitated by ribbed anterior surface of the ear. Such studies were conducted by Gibson and Davis, who showed that ribbed costal cartilage bends in the opposite direction. Using costal cartilage, they demonstrated that if one side of the rib is deprived of the perichondrium, the cartilage will bend to the side where the perichondrium is preserved. When attempting to create a new antihelix from a flat area of auricular cartilage, weakening the anterior surface of the cartilage will cause it to buckle, creating a convex anterior surface. Scoring of the anterior surface of the auricular cartilage at the site of the new antihelix can be done with a needle, abrader, or burr. One should not be too aggressive in this procedure, as sharp edges may form. Access to the anterior surface of the cartilage can be gained from an anterior incision by undercutting the tissue around the edge of the helix from a postauricular incision, or by using a technique described by Spira, scoring the cartilage with a needle inserted through a notch from the anterior. Spira describes his modification of the technique in over 200 otoplasty cases with minimal complications.

Stripping the posterior surface of the ear is technically easier than stripping the anterior surface once access has been established. Physiologically, the cartilage will tend to bend in the opposite direction to that required to create the antihelix, but suturing easily prevents this. Pilz et al. have performed over 300 such otoplasties with excellent results.

Cartilage molding techniques

Cartilage molding techniques are among the earliest otoplasty procedures. They are the most commonly used to reshape the ear cartilage. If successful, these procedures do not require permanent sutures. This reduces the risks associated with foreign body reactions that exist in Mustarde procedures.

The split-cartilage otoplasty technique was first described by Nachlas et al. in 1970. Based on the earlier work of Cloutier, this procedure uses the principle of Gibson and Davis to create a new antihelix. A standard postauricular incision is made, the placement of which is determined after marking the area of the proposed antihelix with a 25-gauge needle dipped in methylene blue. Typically, an elliptical area of skin is excised. Occasionally, if the ear lobe is prominent, an hourglass-shaped incision is made. The needles are then removed. A standard wide dissection is made behind the ear, exposing the tail of the helix, the scaphoid fossa of the antihelix, and the auricular cartilage. An incision is made through the auricular cartilage with a Cottle blade. This should be made approximately 5 mm anterior to the marks marking the apex of the new antihelix. The incision will be curvilinear, parallel to the edge of the helix, and will start from a point located approximately 5 mm below the upper part of the edge of the helix to its tail. Resection of the latter helps to eliminate postoperative bending of the lobe. Triangular wedges are removed perpendicular to the upper and lower edges of the incision. At this stage, the lateral part of the cartilage is attached to its medial part only along the upper edge. The perichondrium is separated from the anterior surface of the cartilage at a distance of approximately 1 cm. The anterior surface of the medial part of the cartilage is processed with a diamond burr until a rounded smooth new antihelix and upper crus are formed. The anterior surface of the lateral part of the cartilage is processed in the same way. The processed medial cartilage is placed in front of the lateral one, restoring the normal contour of the ear. Sutures are not applied to the cartilage. The skin is sutured with a continuous subcutaneous suture.

In split-cartilage otoplasty, the incision edges are turned backward; only one cartilaginous surface is visible in the anterior part of the ear, the smooth convexity of the new antihelix. A modification of this technique described by Schuffencker and Reichert requires the creation of a large V-shaped cartilaginous flap on the side of the proposed antihelix. Instead of a single curved cartilage incision at the site of the new antihelix, the authors isolate a flap of cartilage that is turned upward. The desired convexity is then created by scalloping the anterior surface with a blade.

In any operation, the choice of the correct otoplasty technique depends on the experience and skill of the surgeon. For novice surgeons, the Mustarde technique is the simplest. Reducing the posterior surface of the cartilage with a diamond cutter slightly complicates the procedure, but significantly reduces the likelihood of relapse. In complex cases, more predictable results, in the hands of the author, in the absence of complications associated with Mustarde sutures, are given by otoplasty with cartilage splitting.

Regardless of the otoplasty technique used, a suitable dressing is required to maintain the ear position without undue stress. Cotton wool soaked in mineral oil is placed in the grooves of the ear to prevent swelling. The dressing usually consists of powder and Kerlex coating, and is sealed with Coban tape on top. Drains are recommended. The ears are examined on the first day after surgery. The patient is asked to bring a tennis hair band to the first dressing change. It is applied by the surgeon after removing the dressings and left in place until the stitches are removed, for 1 week. To prevent accidental trauma to the ears for 2 months after surgery, the patient is advised to wear an elastic hair band at night.

Results

Otoplasty is generally a satisfying procedure for both the surgeon and the patient. Achieving symmetry and creating ears with smooth curls and furrows are undoubted advantages of otoplasty. Since similar results can be achieved with a variety of procedures, choosing a technique that gives fewer complications and better long-term results is becoming increasingly important. Many authors have achieved satisfactory results using a wide range of techniques, so the choice of a specific technique is not as critical as mastering its technique.

Complications

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Early complications

The most worrisome complications of otoplasty are hematoma and infection. Excessive pressure exerted on the ear cartilage by a hematoma may lead to necrosis of the cartilage. Infection may cause perichondritis and purulent chondritis, resulting in necrosis and deformation of the ear cartilage. The incidence of hematoma is approximately 1%. Schuffenecker and Reichert reported two cases of hematoma after performing 3,200 cartilage molding procedures.

Prevention of hematoma formation begins with a thorough preoperative assessment of the tendency to bleeding and trauma. In the absence of a family history of hemostasis disorders, laboratory testing of the hemostatic profile is usually not performed. During surgery, bipolar coagulation is used to prevent cartilage necrosis. In cases of bilateral otoplasty, a soaked cotton dressing is applied to the ear that was operated on first. After completion of otoplasty on the opposite side, the first ear should be examined for hemostasis and the absence of hematoma. A small drainage rubber strip is left in the retroauricular groove, which should remain in the incision until the first dressing.

Unilateral pain is the earliest sign of hematoma development. In general, patients experience minimal discomfort after otoplasty for the first 48 hours. Any discomfort should be a reason to remove the dressing and examine the wound. The presence of a hematoma requires opening the wound, stopping the bleeding, washing with an antibiotic solution and re-applying the dressing.

Wound infection usually manifests itself on the 3rd-4th day after surgery. Redness of the wound edges and purulent discharge may be observed in the absence of significant pain. Wound infection should be treated intensively, without waiting for the development of perichondritis or chondritis. In these cases, systemic antibiotic therapy is required, effective also against Pseudomonas aeruginosa. Suppurative chondritis is rare, but is a serious complication when the infection penetrates the cartilage, causing necrosis and resorption. Its development is preceded by deep gnawing pain. The examination results are often inexpressive compared to the symptoms. The diagnosis is established after the failure of conservative treatment of the infection. The principles of treatment consist of systemic antibiotic therapy, surgical debridement and drainage. Repeated sparing surgical debridement is usually required. Resolution of the infection is characterized by a decrease in pain and an improvement in the appearance of the wound. Remote consequences of chondritis can be devastating. Cartilage necrosis leads to permanent ear deformation.

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Late complications

Late complications of otoplasty include suture eruption and aesthetic problems. Suture eruption after Mustarde surgeries is not uncommon and can occur at any stage of the postoperative period. It may be due to improper suture placement, excessive tension on the ear cartilage, or infection. Treatment involves removing the failed sutures. Early suture eruption requires surgical revision to restore the correction. In case of late eruption, revision may not be required if the ear retains the correct shape.

Aesthetic complications include incorrect relationship of the ear and scalp, as well as misalignment of the ear itself. The latter complication includes inadequate correction of protruding ears, its relapse, and excessive correction. Misalignment of the ear can manifest itself in the form of telephone deformation, reverse telephone deformation, ear buckling, ear constriction, and also emphasizing the edges of the cartilage.

Inadequate correction may result from incorrect diagnosis. Ears whose primary deformity is a protruding concha are not amenable to correction by techniques designed to reconstruct the antihelix. Accuracy of preoperative and intraoperative measurements is critical to achieving the desired degree of correction. Other possible factors include suture eruption and loosening. Some reprotrusion due to shape memory of the cartilage is seen in most suture-only repairs. Some reprotrusion has been reported in all cases, particularly at the upper pole. Overcorrection of a prominent ear may result in the ear being pressed against the scalp. This is often more unpleasant for the surgeon than for the patient, but can be prevented by careful preoperative measurements.

Telephone ear deformity is an unnatural result when the middle third of the ear is overcorrected compared to the upper and lower poles. This is often seen after aggressive posterior displacement of the pinna with undercorrection of the upper pole. Telephone deformity can also be associated with an uncorrected, prominent tail of the helix. Reverse telephone deformity occurs when the middle part of the ear protrudes with adequate or overcorrection of the upper pole and lobe. This can result from undercorrection of a prominent pinna. Secondary correction of any of these deformities can result in an over-fitted ear.

Warping of the ear cartilage is observed when using suture techniques when the sutures are placed too far apart. This can be avoided by using the intervals recommended for these techniques.

Disfiguring postauricular scars may vary in severity, from cord-like, along the sutures, to keloid. Cord-like scars are observed only after suture otoplasties, when the threads are wrapped in skin as a result of excessive tension. This leads to the formation of unsightly postauricular scars. With any otoplasty technique, when the postauricular incision is sutured with excessive tension, hypertrophy of the scar may be observed. Keloid formation is rare (more often in black patients). In a large series of studies, the incidence of postoperative keloids was 2.3%. They are initially treated conservatively with injections of triamcinolone acetonide (10, 20, or 40 mg/ml) every 2-3 weeks. The mechanism of action of steroids is to decrease collagen synthesis and increase its breakdown. If surgical excision is required, it is performed sparingly, using a carbon dioxide laser. Some authors recommend leaving a keloid strip to prevent further stimulation of keloid tissue production. Postoperatively, steroid injections are used, which in women can be combined with the application of therapeutic clips. Successful treatment of recurrent keloids with low-dose radiation has also been reported.