Surgical Methods Kaga K, Asato H (eds): Microtia and Atresia – Combined Approach by Plastic and Otologic Surgery. Adv Otorhinolaryngol. Basel, Karger, 2014, vol 75, pp 61–75 (DOI: 10.1159/000350608)
Reconstruction of the Auricle with Autogenous Rib Cartilage Grafts Nobuyuki Kaji · Hirotaka Asato Department of Plastic Surgery, Dokkyo Medical University, Tochigi, Japan
The oldest record of ear reconstruction is considered to be correction of a lobule defect found in Sushruta Samhita of ancient India in the 6th or 7th century BC. The concept of three-dimensional reconstruction of the auricle emerged in the latter half of the 19th century, and supporting materials such as cartilage began to be used at the beginning of the 20th century. Trials using various substances such as ivory, rib cartilages, auricular cartilage, bones, and metals were performed, and biological materials were used for autografts, allografts, and heterografts. It was ultimately concluded that autografting of rib cartilage is best [1]. In 1959, Tanzer [2] reported a surgical method comprising a total of six surgeries in which the ear lobe was reconstructed by using the lower half of the remnant auricle, and a framework made with autologous rib cartilage was transplanted to the temporal subcutaneous region, to be elevated later. Subsequently, various modifications of Tanzer’s method were attempted [3–9]. Of these, the surgical method reported by Brent in 1980 was highly accomplished. In 1992, he reported experience in 600 patients and the method was widely accepted [10–13]. Exploration of how to achieve a better shape is ongoing [14–18]. We established a surgical method (a joint surgery) where canalplasty is performed simultaneously with elevation of the reconstructed ear in patients for whom morphological improvement as well as improved auditory acuity is desired [14]. Various advances have been made for balancing the morphology and function at the time of rib cartilage graft, but considering a potential canalplasty. Details of our procedure for rib cartilage grafting will be explained in this section.
Surgery is performed when the chest circumference reaches 60 cm, as a guide or when a patient reaches 10 years of age (see ‘Deciding on the Timing and Method of Surgery’, this vol., pp. 57–59).
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Appropriate Age for Surgery
Fig. 1. Guide for determining the position of the auricle (particularly in patients with bilateral microtia). Design the scheduled position of auricular reconstruction with the upper pole at the height of the outside edge of the eyebrow, and the lower pole of the lobule at the alar base (arrow 1). In the anterior-posterior direction, design so that the height of the ear concha is positioned at the mastoid process of the temporal bone (arrow 2) of the scheduled position of canalplasty (arrow 3).
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The position of the auricle is very important both morphologically and functionally. When deciding on the vertical position in unilateral patients, the auricle of the unaffected side is traced onto transparent film together with the hair line, eyebrow, and lateral ocular angle; the tracing is then reversed and applied to the surgical field for designing. The hair line may be lower on the affected side, but the position should not be lowered unnecessarily even if the scheduled position for inserting a framework falls under the region covered by hair. This should be taken care of by depilation after surgery. The position in bilateral patients is determined based on the eyebrow, lateral ocular angle, and the height at the alar base of the nose. The position in the anteroposterior direction is determined by positioning the cavity of concha above the mastoid portion of the temporal bone, which is located posterior to the mandibular joint, so that the ear concha matches the position of the reconstructed external auditory canal (EAC) during a joint surgery. Attention should be paid so as not to make the auricle lean forward. In patients with pronounced lowering of the hair line and mandibular hypoplasia due to the 1st and 2nd branchial arch syndrome, deciding on the position of the auricle is difficult, but basically a similar policy should be applied, and the position in the anteroposterior direction is determined based on the temporal bone and that in the vertical direction is based on the balance with the eyebrow and lateral ocular angle (fig. 1) (see ‘Deciding on the Position for Auricular Reconstruction’, this vol., pp. 39–43).
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Kaji · Asato Kaga K, Asato H (eds): Microtia and Atresia – Combined Approach by Plastic and Otologic Surgery. Adv Otorhinolaryngol. Basel, Karger, 2014, vol 75, pp 61–75 (DOI: 10.1159/000350608)
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Deciding on the Position of the Auricle
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Fig. 2. Incision of the remnant auricle. a Make an incision from the top of the lobular arch (arrow 1). Initially make a necessary incision for switch-back rather than make a round incision at the intertragic notch (arrow 2). b Make an incision with a downward arc toward the lobular base on the back. a Design of lobule (anterior view). b Design of lobule (posterior view).
Reconstruction of the Auricle for Lobule-Type Microtia
Incision of the Remnant Ear When an incision of the remnant auricle is made at the constricted part of the upper lobule, the reconstructed auricle would be shaped like a question mark and look unnatural [3]. So, the incision is started at the top of the lobular arc, and in the front, the remnant lobule is utilized as much as possible for the reconstructed lobule. Whereas in the back, the incision is arced toward the lobular base with downward convex for the skin at the back of the remnant lobule to be used as a skin flap covering the framework. The intertragic notch is incised to form an arch during final suturing, so a vertical incision alone is initially made of the length required for shifting the lobule backward (switch-back) (fig. 2).
Reconstruction of Auricle Kaga K, Asato H (eds): Microtia and Atresia – Combined Approach by Plastic and Otologic Surgery. Adv Otorhinolaryngol. Basel, Karger, 2014, vol 75, pp 61–75 (DOI: 10.1159/000350608)
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Position of Switch-Back and Design of the Postauricular Incision Rather than determining the design of the postauricular incision from the start, mark the point where the switch-back of the lobule is made as naturally as possible after lobular incision, and design to form an arch starting with that point. Design a skin incision for resection of the remnant cartilage at the ridgeline of the remnant auricle, and a subcutaneous pedicle (an undissected portion to maintain blood circulation of a flap for a subcutaneous pocket) inside the cavity of concha (fig. 3).
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Fig. 3. Design of the position of switch-back of the lobule and the incision behind the ear. a Confirm the point at which the lobule appears most natural when put on and mark it. b Make an incision behind the ear that forms an arc from the point of switch-back (arrow 1). Design the subcutaneous pedicle inside the ear concha (arrow 2). Design a skin incision for resection of the remnant cartilage at the ridgeline of the remnant ear (arrow 3). a Marking the position of switch-back. b Incision behind the ear and design of remnant cartilage resection.
Harvesting Rib Cartilage Harvest the 6th to 8th rib cartilages from the right side for unilateral microtia and from the same side of reconstruction for bilateral microtia (fig. 5a). Make an oblique skin incision from 4 to 5 cm above the 7th rib cartilage up to the perichondrium and
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Kaji · Asato Kaga K, Asato H (eds): Microtia and Atresia – Combined Approach by Plastic and Otologic Surgery. Adv Otorhinolaryngol. Basel, Karger, 2014, vol 75, pp 61–75 (DOI: 10.1159/000350608)
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Resection of the Remnant Cartilage and Creation of a Subcutaneous Pocket After hydro-dissection with a subcutaneous injection of epinephrine solution diluted 200,000-fold, the skin is undermined about 1 cm wider than the scheduled area for inserting a framework by leaving the subcutaneous pedicle from the postauricular skin incision. A skin flap is elevated by straight scissors in the layer immediately below the skin to which fat is slightly conserved to preserve the subdermal vascular plexus. Dissection of the anterior portion of the pocket is performed, followed by resection of the remnant cartilage from an open skin incision to the ridgeline of the remnant auricle (fig. 4a). When dissecting above the cartilage, it should be done immediately below the skin, not in the layer between the fat and the cartilage, so that the flap is as thick as the pocket. This way, a consistently thin subcutaneous pocket with good vascular circulation can be created. While waiting for a framework to be completed, insert gauze or a slightly enlarged Foley balloon catheter into the subcutaneous pocket for intraoperative expansion, and obtain as much extra skin as possible for covering the framework [11] (fig. 4b).
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Fig. 4. Creation of a subcutaneous pocket and intraoperative expansion. a Dissect under the skin from a skin incision behind the ear, leaving the subcutaneous pedicle (arrow 1). Remnant cartilage (arrow 2) can be openly resected because a skin incision is also made at the ridgeline of the remnant auricle. b Suture the lobule, and stuff gauze inside the subcutaneous pocket to expand the flap. a Creation of a subcutaneous pocket and resection of remnant cartilage. b Suture of the lobule and intraoperative expansion of the flap.
Creation of the Framework Creation of a Base Frame A base frame, except for the part of the intertragic notch, is made with the flat portion of the 6th and 7th rib cartilages connected by wire sutures. A framework is made up to the antitragus in case of concha-type microtia and small concha-type microtia, but
Reconstruction of Auricle Kaga K, Asato H (eds): Microtia and Atresia – Combined Approach by Plastic and Otologic Surgery. Adv Otorhinolaryngol. Basel, Karger, 2014, vol 75, pp 61–75 (DOI: 10.1159/000350608)
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the intercostal muscle, and widely dissect the rectus abdominis muscle and external oblique muscle to expose the 6th to 8th rib cartilages. Dissect rib cartilages from the perichondrium to harvest the whole length from the joint with the sternum at the inside and up to the rib at the outside. Completely preserve the perichondrium to the donor side instead of harvesting along with the cartilage, and repair the incision with sutures after harvesting. We usually use the 6th and 7th cartilages for a base frame and the lower ridgeline of the 8th cartilage for the helix, and the remainder for creation of the antihelix depending on the shape of the cartilage. Bank the remaining cartilage under the chest skin for use as a columella for maintaining protrusion during elevation of the auricle [3, 19] (fig. 5b). It is ideal when several blocks of 15 mm in height can be secured. Create a new space for embedding under the skin of the wound margin to make it easier to retrieve for subsequent surgeries.
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Fig. 5. a Harvesting rib cartilage. Harvest the 6th, 7th, and 8th rib cartilages from the right side for unilateral microtia and from the same side to reconstruction for bilateral microtia. b Creation of the framework (base frame, helix, and antihelix). Create a base frame with the 6th and 7th rib cartilages and use the lower margin of the 8th cartilage as the helix. Construct the antihelix using the portion where the curve of the ear concha is obtained (arrow 1). Make the portion from the intertragic notch to the tragus of the base frame by adding the remaining cartilage (arrow 2). Bank the medial side of the 6th and 7th cartilages (arrow 3). c Chiseling of the helix (8th rib cartilage). Use the scalpeled surface of the lower margin of the 8th cartilage as the contact surface with the base frame. Use the original edge to obtain the ridgeline of the helix. Chisel the inner surface of the helix with a woodcarving knife to make the cartilage pliable. Leave the ridgeline of the helix (arrow 1) and the contact surface with the base frame (arrow 2).
Creation of the Helix and Antihelix Cut the total length of the underside of the 8th rib cartilage about 5 mm from the margin with a scalpel for use as the helix. The surface resected with the scalpel is used as a bonding surface with the base frame, and to make the original edge of the lower line
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Kaji · Asato Kaga K, Asato H (eds): Microtia and Atresia – Combined Approach by Plastic and Otologic Surgery. Adv Otorhinolaryngol. Basel, Karger, 2014, vol 75, pp 61–75 (DOI: 10.1159/000350608)
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the portion from the intertragic notch to the tragus is required for lobule-type microtia, so it should be made by adding surplus cartilage (fig. 5b). A 38-gauge stainless wire suture with bilateral straight needles is used for joining cartilages. For unilateral microtia, the normal side is traced and reversed for use as a template. A framework is made about 1 mm smaller in circumference than the template, considering the thickness of the flap. For the same reason, allow an ample size for the cavity of concha and the intertragic notch. The base frame should be 4 mm thick so that the completed framework is less than 1 cm at the most. The upper anterior portion of the base frame leading to the crus of helix should be sloped to become thinner so the crus of helix is not higher than the base frame. Create the part of the lobule in order to have the width required only for making the silhouette of the intertragic notch and need to retain the softness of the lobule without inserting the cartilage too deeply in the lobule.
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as the helix ridgeline. The medial side of the 8th rib cartilage is usually a free end without a joint with the sternum, so the free end is used for the crus of helix. Cut the opposite costal end to taper so that the helix naturally disappears at the site of transition to the lobule. To make the cartilage pliable and to express the curly shape of the helix, make a groove on the inside of the helix with a round wood-carving chisel. At this time, retain the contact surface with the base frame and the original lower edge of the 8th rib cartilage, which will be the ridgeline of the helix (fig. 5b). Next, create the antihelix. Any of the remaining cartilage may be used, but select a portion yielding the curvature corresponding to the dike of the posterior wall of the ear concha (fig. 5b). Construct the inferior crus of the antihelix together with the triangular fossa by directly engraving on the base frame. Create the antihelix high enough so that the silhouette of the ear concha becomes obvious, and make the inner slope of the ridgeline steep whereas the outer slope should be gently chipped to make a natural scaphoid fossa. The end of the superior crus should be naturally tapered following the outer slope. Continue the lower end of the antihelix to the antitragus and create the antitragus as well (fig. 6).
Reconstruction of Auricle Kaga K, Asato H (eds): Microtia and Atresia – Combined Approach by Plastic and Otologic Surgery. Adv Otorhinolaryngol. Basel, Karger, 2014, vol 75, pp 61–75 (DOI: 10.1159/000350608)
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Fig. 6. Assembly of the framework. Provide ample space for the cavity of concha and the intertragic notch, and make the slope of the posterior wall of the ear concha steep up to the antihelix (arrow 1). Slant the portion of the base frame continuing to the crus of helix by thinning. Create the inferior crus of the antihelix by directly chiseling the base frame and make it lower than the superior crus (arrow 2). Fix the helix and antihelix over the base frame, and chisel the inner slant from the ridgeline of the antihelix sharply and the outer slant gently (arrow 3). Naturally taper the ends. Create the antitragus and the antihelix in a mass (arrow 4). Finally, chisel the base frame deeply to make the triangular fossa and scaphoid fossa, and make a suction hole on the bottom (arrows 5 and 6).
Fixation of the Helix and Antihelix Place the helix on the base frame and fix with a wire suture with bilateral needles from the end of lobule. Fix the end of the crus of helix at the back of the base frame. Insert the wire from the front side of the framework, twist it at the back, and fix it. Make slits in the cartilage surface to embed the wire to prevent it from being exposed. Next, fix the antihelix in the same manner. Creation of the Inferior Crus of the Antihelix, Triangular Fossa and Scaphoid Fossa To reconstruct the three-dimensional shape of the auricle, create the inferior crus by chiseling the base frame so that it is located below the superior crus and the crus of helix lower than that. After fixing the helix and the antihelix to the base frame, create the triangular fossa and scaphoid fossa with a wood-carving chisel, and open a suction hole at the base to adhere the skin flap and the rib cartilage framework with a suction drain [10] (fig. 6). Insertion of the Framework Insert a flat type J-VAC® drain (Johnson & Johnson K.K.) into the subcutaneous pocket before inserting the framework. Subcutaneously, place the drain tube as far away from the pocket as possible behind the ear to produce an airtight seal when suctioned. Then, insert the framework above the drain. Suture to fix the anterior peak of the helix and the tragus by covering them with subcutaneous tissues at the anterior border of the framework so that the silhouette of the anterior border of the helix and tragus does not stand out (fig. 7a). Given that the remnant lobule tends to migrate forward of the framework, insert the lower end of the framework into the small pocket under the skin of the lobule, and fix it with absorbable thread.
Dressing Avoid bolster fixation because it may suppress blood circulation in the flap. Continuously suction with a drain and stuff wet cotton into the ear concha, scaphoid fossa, and triangular fossa to prevent hematoma. Encircle the auricle with a doughnutshaped sponge to protect the reconstructed auricle from the pressure of a pillow.
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Suturing of the Skin Flap When suturing the skin flap, suction with the drain to adhere the flap and the framework while checking the contours of the auricle. To produce distinct contours, it is important to amply tuck in the flap into the dents of the ear concha, intertragic notch, scaphoid fossa, and triangular fossa. Trim the wrinkles and uneven skin covering the remnant cartilage as well as possible. Construct the tragus by wrapping the tragus portion of the framework with the anterior flap of the remnant auricle. At the intertragic notch, cut out the skin of the anterior lobule in a U-shape to match the shape of the framework, cut a fan-like slit into the flap of the subcutaneous pocket, and suture to make it deeper (fig. 7b).
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Fig. 7. a Insertion and fixation of the framework. Suture to fix the anterior apex of the helix (arrow 1) and the tragus (arrow 2) at the anterior border of the framework by covering with the subcutaneous tissues so that the contour of the anterior border does not protrude. b Suturing of the skin flap. Adhere the skin flap and the framework by suctioning with the drain, and trim the uneven skin covering the remnant cartilage as well as possible and the wrinkles remaining after tucking the skin flap into a dent (arrow 1). Dissect the skin of the lobular anterior in a U-shape at the intertragic notch, and make a fan-like slit into the skin flap to make it deeper (arrow 2). Create the tragus by wrapping the tragus of the framework with the skin flap (arrow 3).
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Reconstruction of Auricle Kaga K, Asato H (eds): Microtia and Atresia – Combined Approach by Plastic and Otologic Surgery. Adv Otorhinolaryngol. Basel, Karger, 2014, vol 75, pp 61–75 (DOI: 10.1159/000350608)
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Fig. 8. Design of the incision of the remnant auricle for small concha-type microtia. a Start the incision at the widest anterior-posterior diameter (arrow 1), and make a vertical incision to the ear concha for switch-back (arrow 2). b Design the subcutaneous pedicle inside the scheduled position of the ear concha (arrow 1), and design the incision of the posterior remnant auricle to course below it (arrow 2). a Anterior view. b Posterior view.
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Fig. 9. Switch-back of the lobule and resection of remnant cartilage in small concha-type microtia. a To provide a sufficient amount for switch-back, dissect the cartilage of the posterior wall of the ear concha by leaving the contour of the intertragic notch and antitragus (the portion inside the dotted line and shaded lines: arrow 1). Mark the point of switch-back where the shape of the intertragic notch appears the most natural (arrow 2). b Design to form a mild arc from the marked point for switch-back (arrow 1). Design a skin incision on the ridgeline of the remnant auricle as per lobulartype microtia (arrow 2). c Dissect the cartilage from the skin of the anterior auricle (arrow 1), and remove the cartilage inside the dotted line and diagonal lines by leaving the contour of the intertragic notch and antitragus (arrow 2). a Incision in the anterior remnant auricle and marking of the position of switch-back. b Incision in the posterior ear and design of resection of remnant cartilage. c Resection of the cartilage of the ear concha (enlargement of b shown from the incision on the back of the auricle).
Reconstruction of Small Concha-Type Microtia and Concha-Type Microtia
Designing the Position of Switch-Back and the Incision behind the Ear After the incision in the remnant auricle, mark a switch-back point to produce the shape of the intertragic notch as naturally as possible (fig. 9a). Design an incision line behind the ear to form a slight arch from that point (fig. 9b). Design a subcutaneous pedicle for small concha-type microtia in the same manner as for lobule-type micro-
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Incision of the Remnant Auricle The incision of the remnant auricle may vary depending on the amount of remnant auricle. As a guide, the incision is started at the widest diameter of the anterior-posterior dimension, and the lower region of the cavity of concha of the remnant auricle, or the region from the tragus, intertragic notch, and antitragus, is used for construction of the auricle. A vertical incision is made to the ear concha of the remnant auricle to enable sufficient switch-back. Resect the cartilage of the posterior wall of the ear concha by leaving the silhouette of the intertragic notch and antitragus to facilitate shifting (fig. 8, 9c).
Fig. 10. Creation of the framework. Create the framework basically in the same manner as for lobule-type microtia up to the antitragus.
tia (fig. 8b). Because the size of the required subcutaneous pocket varies depending on the amount of remnant auricle used for reconstruction of the auricle in the concha-type, determine the necessity of a subcutaneous pedicle as appropriate for each patient. Resection of Remnant Cartilage and Creation of a Subcutaneous Pocket The same techniques as for lobule-type are employed. Completely resect the remnant cartilage except for the portion used for reconstruction (fig. 9b). Creation of a Framework Similarly to the lobule-type, create a framework up to the antitragus using the 6th to the 8th rib cartilages (fig. 10). Bank the remaining cartilage under the skin of the chest.
Dressing To be done as for lobule-type.
Reconstruction of Auricle Kaga K, Asato H (eds): Microtia and Atresia – Combined Approach by Plastic and Otologic Surgery. Adv Otorhinolaryngol. Basel, Karger, 2014, vol 75, pp 61–75 (DOI: 10.1159/000350608)
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Joining the Framework with the Remnant Auricle and Wound Closure After inserting the suction drain, insert the framework into the subcutaneous pocket. Subcutaneously suture to fix the anterior margin of the crus of helix of the framework, place the cartilage of the antitragus of the remnant auricle over the antitragus of the framework, and suture with absorbable thread (fig. 11a). Trim the excess skin while suctioning with the drain and suture to close the wound (fig. 11b).
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Fig. 11. Connecting the framework and remnant cartilage and suture of the skin flap. a Cover the subcutaneous tissue over the anterior apex of the helix at the anterior border of the framework and suture to fix (arrow 1). Overlay the antitragus of the remnant cartilage over the antitragus of the framework and suture with absorbable thread to fix them (arrow 2). b Adhere the skin flap and framework by suctioning with a drain, and trim the uneven skin covering the remnant cartilage as well as possible (arrows 1 and 2). a Fixation of framework and remnant cartilage. b Suturing of the skin flap.
Advances in auricular reconstruction by rib cartilage grafting have relied greatly on improvements in the framework. The most commonly employed methods are the Tanzer method, where a base frame is created with the 6th and 7th rib cartilages and the helix with the 8th rib [2, 5], and the Brent method [10, 11], which improved on the Tanzer method and has demonstrated stable results [5–7, 11, 12, 14–16]. We also consider it essential to only harvest these three rib cartilages and perform surgery when the patient’s chest circumference reaches 60 cm or more to permit harvesting of sufficient amounts of cartilage [7, 15, 16]. With respect to the shape of the framework, the helix and the center of the antihelix (posterior wall of the ear concha) should be higher, with emphasis placed on the depth of the scaphoid fossa, triangular fossa, and ear concha, to fully express the 3-dimensional structure of the auricle and its contours [6, 7, 9, 11, 15, 20]. However, the height should not exceed 10 mm at the most in consideration of vascular circulation in the flap of the subcutaneous pocket. A suction hole is opened onto the base frame of the scaphoid fossa and triangular fossa for continuous suction with a suction drain for 2 weeks after surgery [11]. Some consider a thick auricle to be unnatural [21], but it has been reported that it becomes thin and soft over long-term observation [15, 16], and we create a 4-mm thick base frame to prevent breakage. As a functional device for canalplasty, the curve of the ear concha is made larger and wider. This is because the opening of the EAC is made at a slightly upper posterior region relative to the normal position when the EAC is constructed
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Discussion
Reconstruction of Auricle Kaga K, Asato H (eds): Microtia and Atresia – Combined Approach by Plastic and Otologic Surgery. Adv Otorhinolaryngol. Basel, Karger, 2014, vol 75, pp 61–75 (DOI: 10.1159/000350608)
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via an approach to the tympanic cavity from the mastoid portion of the temporal bone, which is upper posterior to the temporomandibular joint via the mastoid air cells. By creating a wider ear concha, it is possible to widen the anastomotic site of the EAC and the ear concha during a joint surgery, which will be effective for improving auditory acuity and preventing post-operative stenosis [14]. Not only the shape of the framework, but also the site of its insertion is critical, and we position the ear concha to the mastoid portion of the temporal bone, which is posterior to the temporomandibular joint. A more natural appearance of the auricle is achieved by paying attention to both its shape and position [3, 5, 10]. In previous reports, prevention of forward rotation of the long axis of the auricle was considered the most important aspect with respect to the anterior-posterior dimensions [5, 10, 15]; in addition, in determining the position, we place emphasis on the functional aspect as well as considering the slant of the auricle [14]. In fact, the position of the auricle constructed by our method looks natural. Creation of the subcutaneous pocket is an important process requiring technique for expressing the contour. Tanzer [2] and Brent [10] performed transposition of the remnant lobule in separate stages to maintain the circulation of the flap , but it is possible to prevent necrosis of the flap by providing a subcutaneous pedicle as shown by Fukuda and others [3, 8, 16]. We continue the incision up to the upper pole along the ridgeline of the remnant auricle for resection of remnant cartilage, but have not experienced a skin necrosis complication considered due to the skin incision. Rather, skin necrosis is considered to occur because of tension when the size of the flap is not sufficient to cover the uneven framework [3, 16]. It is vital to preserve the subdermal vascular plexus during flap elevation [2, 3, 7, 10]. Tanzer [2] argued that it should be as thin as possible, whereas Fukuda [15] considered that resorption of cartilage is likely to occur after a few years and a wire may be exposed if it is too thin. Ogino [7] therefore recommends dissection at a thickness immediately below the skin where a small amount of fat is attached, and we use that layer when dissecting. The skin above the remnant cartilage may be necrotized subsequent to forceful dissection, but remnant cartilage can easily be resected openly and a flap can be elevated safely and at a consistent thickness with our method for making an incision up to the upper pole of the remnant auricle. In addition to skin necrosis and wire exposure, chest deformation at the site of harvesting the rib cartilage is considered a problem [22, 23]. It has been reported that chest deformation is unlikely to occur when patients are 7 years of age or older (or 10 years or older) [7, 15, 16, 22], so we perform surgery when patients are around 10 years of age. The perichondrium is preserved at the donor site to maintain the reproductive ability of the cartilage [24]. Some surgeons also harvest the perichondrium in expectation of the take and growth of the framework [3], but Fukuda [15] considered that the result would not be affected by the presence or absence of the perichondrium. Deformity of the chest wall may develop even when the perichondrium is preserved [23], and various methods have attempted to prevent this, such as preservation of the site of rib cartilage
transposition [12, 22], returning the extra cartilage to the donor site [24],and harvesting the rib cartilage by chiseling rather than in full thickness [25] (see ‘Chest Wall Deformity at the Site of Costal Cartilage Harvesting’, this vol., pp. 110–113). Further improvements need to be made in auricular reconstruction by rib cartilage graft, such as improvements in achieved auditory acuity, creative ideas for obtaining stable long-term results, and considerations for invasion to the donor site. Since the argument of Dunton’s group in 1964 that auricular reconstruction, which requires much labor but produces little fruit, should be abandoned and that attachment of an artificial ear would be best, some surgeons still select an artificial ear [1, 3]. However, it is natural for patients to feel that a prosthesis is not satisfactory [3]. Cronin reported auricular reconstruction using a silicone frame in 1966 as the material other than autologous tissues for support of the auricle, and it has been succeeded by Omori et al. [26]. However, many consider transplantation of autologous rib cartilage to be superior because a silicone frame is susceptible to trauma and easily exposed, relief from infection is difficult, and there may be anxiety associated with implantation of a foreign substance [1, 12, 15, 18]. Against this background, we who support auricular reconstruction by autologous rib cartilage graft should minimize invasion at the donor site and the number of surgeries, make shape and function compatible, and establish long-term stability. Details of our surgical procedure by rib cartilage graft aiming for compatibility of shape and function were explained above. Transplantation to mice of tissue-engineered bovine cartilage in the shape of a human ear was reported about 10 years ago [27], and application of the technology to humans was expected. Brent et al. [18] also performed independent research on a bioengineered framework, but clinical application is yet to be achieved. Despite the advances made in autologous rib cartilage grafting during the last half-century and on-going refinement efforts, we still have a long way to go before this new technique of tissue engineering becomes established in the clinical setting. There is no doubt that further advances in autologous rib cartilage grafting for auricular reconstruction are needed in the future.
1 Nishimura Y, Ogino Y: Historical and future reviews in ear reconstruction. Jpn J Plast Reconstr Surg 1974; 17:461–468. 2 Tanzer RC: Total reconstruction of the external ear. Plast Reconstr Surg 1959;23:1–15. 3 Fukuda O: Reconstruction of microtia. 1. The design of the proposed ear and the operative procedures of cartilage graft. Jpn J Plast Reconstr Surg 1974; 17: 469–483. 4 Fukuda O: Reconstruction of microtia. 2. The construction of cartilage framework. Jpn J Plast Reconstr Surg 1975;18:685–695.
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5 Tanzer RC: Total reconstruction of the auricle: the evolution of a plan of treatment. Plast Reconstr Surg 1971;47:523–533. 6 Spina V, Kamakura L, Psillakis JM: Total reconstruction of the ear in congenital microtia. Plast Reconstr Surg 1971;48:349–357. 7 Ogino Y: Total auricle reconstruction in cases of unilateral microtia. Jpn J Plast Reconstr Surg 1989; 32: 891–907. 8 Nagata S: A new method of total reconstruction of the auricle for microtia. Plast Reconstr Surg 1993;92: 187–201.
Kaji · Asato Kaga K, Asato H (eds): Microtia and Atresia – Combined Approach by Plastic and Otologic Surgery. Adv Otorhinolaryngol. Basel, Karger, 2014, vol 75, pp 61–75 (DOI: 10.1159/000350608)
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References
19 Nagata S: Modification of the stages in total reconstruction of the auricle. IV. Ear elevation for the constructed auricle. Plast Reconstr Surg 1994; 93: 254– 266. 20 Tanzer RC, Rueckert F, Brown F: Technical advances in ear reconstruction with autogenous rib cartilage grafts: personal experience with 1,200 cases. Plast Reconstr Surg 1999;104:335–338. 21 Walton RL, Beahm EK: Auricular reconstruction for microtia. II. Surgical techniques. Plast Reconstr Surg 2002;110:234–249. 22 Ohara K, Nakamura K, Ohta E: Chest wall deformities and thoracic scoliosis after costal cartilage graft harvesting. Plast Reconstr Surg 1997;99:1030–1036. 23 Thompson HG, Kim TY, Ein SH: Residual problems in chest donor sites after microtia reconstruction: a long-term study. Plast Reconstr Surg 1995; 95: 961– 968. 24 Kawanabe Y, Nagata S: A new method of costal cartilage harvest for total auricular reconstruction. 1. Avoidance and prevention of intraoperative and postoperative complication and problems. Plast Reconstr Surg 2006;117:2011–2018. 25 Yotsuyanagi T, Mikami M, Yamauchi M, Higuma Y, Urushidate S, Ezoe K: A new technique for harvesting costal cartilage with minimum sacrifice at the donor site. J Plast Reconstr Aesthet Surg 2006; 59: 352– 359. 26 Ohmori S, Matsumoto K, Nakai H: Reconstruction of microtic ear by use of silicon rubber frame. Jpn J Plast Reconstr Surg 1974;17:484–491. 27 Cao Y, Vacanti JP, Paige KT, Upton J, Vacanti CA: Transplantation of chondrocytes utilizing a polymer-cell construct to produce tissue-engineered cartilage in the shape of a human ear. Plast Reconstr Surg 1997;100:297.
Nobuyuki Kaji Department of Plastic Surgery, Dokkyo Medical University 880 Kitakobayashi, Mibu-Machi, Shimotsuga-gun Tochigi 320-0293 (Japan) E-Mail [email protected]
Reconstruction of Auricle Kaga K, Asato H (eds): Microtia and Atresia – Combined Approach by Plastic and Otologic Surgery. Adv Otorhinolaryngol. Basel, Karger, 2014, vol 75, pp 61–75 (DOI: 10.1159/000350608)
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9 Nagata S: Modification of the stages in total reconstruction of the auricle. I. Grafting the three-dimensional costal cartilage framework for lobule-type microtia. Plast Reconstr Surg 1994;93:221–230. 10 Brent B: The correction of microtia with autogenous cartilage grafts. I. The classic deformity. Plast Reconstr Surg 1980;66:1–12. 11 Brent B: Auricular repair with autogenous rib cartilage grafts: two decades of experience with 600 cases. Plast Reconstr Surg 1992;90:355–374. 12 Osorno G: Autogenous rib cartilage reconstruction of congenital ear defects: Report of 110 cases with Brent’s technique. Plast Reconstr Surg 1999; 104: 1951–1962. 13 Firmin F: Ear reconstruction in cases of typical microtia. Personal experience based in 352 microtic ear corrections. Scand J Plast Reconstr Surg Hand Surg 1998;32:35–47. 14 Asato H, Kaga K, Kaji N, Aiba E, Mitoma Y, Harii K: Simultaneous ear elevation and canal plasty as a combined surgery for microtia patients. Jpn J Plast Reconstr Surg 2003;46:779–787. 15 Fukuda O: Changes of my ideas for reconstruction of microtia. Jpn J Plast Reconstr Surg 2005;48:203–213. 16 Maegawa J, Mikami T, Ogino Y: Problems and refinements in ear reconstruction encountered in long-term follow-up in microtia patients. Jpn J Plast Reconstr Surg 2003;46:807–817. 17 Yotsuyanagi T, Yokoi K, Nihei Y, Sawada Y: Management of the hairline using a local flap in total reconstruction for microtia. Plast Reconstr Surg, 1999; 104:41–47. 18 Brent B: Technical advances in ear reconstruction with autogenous rib cartilage grafts: Personal experience with 1,200 cases. Plast Reconstr Surg 1999;104: 319–334.
Reconstruction of the Auricle with Autogenous Rib Cartilage Grafts Nobuyuki Kaji · Hirotaka Asato Department of Plastic Surgery, Dokkyo Medical University, Tochigi, Japan
The oldest record of ear reconstruction is considered to be correction of a lobule defect found in Sushruta Samhita of ancient India in the 6th or 7th century BC. The concept of three-dimensional reconstruction of the auricle emerged in the latter half of the 19th century, and supporting materials such as cartilage began to be used at the beginning of the 20th century. Trials using various substances such as ivory, rib cartilages, auricular cartilage, bones, and metals were performed, and biological materials were used for autografts, allografts, and heterografts. It was ultimately concluded that autografting of rib cartilage is best [1]. In 1959, Tanzer [2] reported a surgical method comprising a total of six surgeries in which the ear lobe was reconstructed by using the lower half of the remnant auricle, and a framework made with autologous rib cartilage was transplanted to the temporal subcutaneous region, to be elevated later. Subsequently, various modifications of Tanzer’s method were attempted [3–9]. Of these, the surgical method reported by Brent in 1980 was highly accomplished. In 1992, he reported experience in 600 patients and the method was widely accepted [10–13]. Exploration of how to achieve a better shape is ongoing [14–18]. We established a surgical method (a joint surgery) where canalplasty is performed simultaneously with elevation of the reconstructed ear in patients for whom morphological improvement as well as improved auditory acuity is desired [14]. Various advances have been made for balancing the morphology and function at the time of rib cartilage graft, but considering a potential canalplasty. Details of our procedure for rib cartilage grafting will be explained in this section.
Surgery is performed when the chest circumference reaches 60 cm, as a guide or when a patient reaches 10 years of age (see ‘Deciding on the Timing and Method of Surgery’, this vol., pp. 57–59).
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Appropriate Age for Surgery
Fig. 1. Guide for determining the position of the auricle (particularly in patients with bilateral microtia). Design the scheduled position of auricular reconstruction with the upper pole at the height of the outside edge of the eyebrow, and the lower pole of the lobule at the alar base (arrow 1). In the anterior-posterior direction, design so that the height of the ear concha is positioned at the mastoid process of the temporal bone (arrow 2) of the scheduled position of canalplasty (arrow 3).
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The position of the auricle is very important both morphologically and functionally. When deciding on the vertical position in unilateral patients, the auricle of the unaffected side is traced onto transparent film together with the hair line, eyebrow, and lateral ocular angle; the tracing is then reversed and applied to the surgical field for designing. The hair line may be lower on the affected side, but the position should not be lowered unnecessarily even if the scheduled position for inserting a framework falls under the region covered by hair. This should be taken care of by depilation after surgery. The position in bilateral patients is determined based on the eyebrow, lateral ocular angle, and the height at the alar base of the nose. The position in the anteroposterior direction is determined by positioning the cavity of concha above the mastoid portion of the temporal bone, which is located posterior to the mandibular joint, so that the ear concha matches the position of the reconstructed external auditory canal (EAC) during a joint surgery. Attention should be paid so as not to make the auricle lean forward. In patients with pronounced lowering of the hair line and mandibular hypoplasia due to the 1st and 2nd branchial arch syndrome, deciding on the position of the auricle is difficult, but basically a similar policy should be applied, and the position in the anteroposterior direction is determined based on the temporal bone and that in the vertical direction is based on the balance with the eyebrow and lateral ocular angle (fig. 1) (see ‘Deciding on the Position for Auricular Reconstruction’, this vol., pp. 39–43).
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Deciding on the Position of the Auricle
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Fig. 2. Incision of the remnant auricle. a Make an incision from the top of the lobular arch (arrow 1). Initially make a necessary incision for switch-back rather than make a round incision at the intertragic notch (arrow 2). b Make an incision with a downward arc toward the lobular base on the back. a Design of lobule (anterior view). b Design of lobule (posterior view).
Reconstruction of the Auricle for Lobule-Type Microtia
Incision of the Remnant Ear When an incision of the remnant auricle is made at the constricted part of the upper lobule, the reconstructed auricle would be shaped like a question mark and look unnatural [3]. So, the incision is started at the top of the lobular arc, and in the front, the remnant lobule is utilized as much as possible for the reconstructed lobule. Whereas in the back, the incision is arced toward the lobular base with downward convex for the skin at the back of the remnant lobule to be used as a skin flap covering the framework. The intertragic notch is incised to form an arch during final suturing, so a vertical incision alone is initially made of the length required for shifting the lobule backward (switch-back) (fig. 2).
Reconstruction of Auricle Kaga K, Asato H (eds): Microtia and Atresia – Combined Approach by Plastic and Otologic Surgery. Adv Otorhinolaryngol. Basel, Karger, 2014, vol 75, pp 61–75 (DOI: 10.1159/000350608)
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Position of Switch-Back and Design of the Postauricular Incision Rather than determining the design of the postauricular incision from the start, mark the point where the switch-back of the lobule is made as naturally as possible after lobular incision, and design to form an arch starting with that point. Design a skin incision for resection of the remnant cartilage at the ridgeline of the remnant auricle, and a subcutaneous pedicle (an undissected portion to maintain blood circulation of a flap for a subcutaneous pocket) inside the cavity of concha (fig. 3).
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Fig. 3. Design of the position of switch-back of the lobule and the incision behind the ear. a Confirm the point at which the lobule appears most natural when put on and mark it. b Make an incision behind the ear that forms an arc from the point of switch-back (arrow 1). Design the subcutaneous pedicle inside the ear concha (arrow 2). Design a skin incision for resection of the remnant cartilage at the ridgeline of the remnant ear (arrow 3). a Marking the position of switch-back. b Incision behind the ear and design of remnant cartilage resection.
Harvesting Rib Cartilage Harvest the 6th to 8th rib cartilages from the right side for unilateral microtia and from the same side of reconstruction for bilateral microtia (fig. 5a). Make an oblique skin incision from 4 to 5 cm above the 7th rib cartilage up to the perichondrium and
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Kaji · Asato Kaga K, Asato H (eds): Microtia and Atresia – Combined Approach by Plastic and Otologic Surgery. Adv Otorhinolaryngol. Basel, Karger, 2014, vol 75, pp 61–75 (DOI: 10.1159/000350608)
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Resection of the Remnant Cartilage and Creation of a Subcutaneous Pocket After hydro-dissection with a subcutaneous injection of epinephrine solution diluted 200,000-fold, the skin is undermined about 1 cm wider than the scheduled area for inserting a framework by leaving the subcutaneous pedicle from the postauricular skin incision. A skin flap is elevated by straight scissors in the layer immediately below the skin to which fat is slightly conserved to preserve the subdermal vascular plexus. Dissection of the anterior portion of the pocket is performed, followed by resection of the remnant cartilage from an open skin incision to the ridgeline of the remnant auricle (fig. 4a). When dissecting above the cartilage, it should be done immediately below the skin, not in the layer between the fat and the cartilage, so that the flap is as thick as the pocket. This way, a consistently thin subcutaneous pocket with good vascular circulation can be created. While waiting for a framework to be completed, insert gauze or a slightly enlarged Foley balloon catheter into the subcutaneous pocket for intraoperative expansion, and obtain as much extra skin as possible for covering the framework [11] (fig. 4b).
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Fig. 4. Creation of a subcutaneous pocket and intraoperative expansion. a Dissect under the skin from a skin incision behind the ear, leaving the subcutaneous pedicle (arrow 1). Remnant cartilage (arrow 2) can be openly resected because a skin incision is also made at the ridgeline of the remnant auricle. b Suture the lobule, and stuff gauze inside the subcutaneous pocket to expand the flap. a Creation of a subcutaneous pocket and resection of remnant cartilage. b Suture of the lobule and intraoperative expansion of the flap.
Creation of the Framework Creation of a Base Frame A base frame, except for the part of the intertragic notch, is made with the flat portion of the 6th and 7th rib cartilages connected by wire sutures. A framework is made up to the antitragus in case of concha-type microtia and small concha-type microtia, but
Reconstruction of Auricle Kaga K, Asato H (eds): Microtia and Atresia – Combined Approach by Plastic and Otologic Surgery. Adv Otorhinolaryngol. Basel, Karger, 2014, vol 75, pp 61–75 (DOI: 10.1159/000350608)
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the intercostal muscle, and widely dissect the rectus abdominis muscle and external oblique muscle to expose the 6th to 8th rib cartilages. Dissect rib cartilages from the perichondrium to harvest the whole length from the joint with the sternum at the inside and up to the rib at the outside. Completely preserve the perichondrium to the donor side instead of harvesting along with the cartilage, and repair the incision with sutures after harvesting. We usually use the 6th and 7th cartilages for a base frame and the lower ridgeline of the 8th cartilage for the helix, and the remainder for creation of the antihelix depending on the shape of the cartilage. Bank the remaining cartilage under the chest skin for use as a columella for maintaining protrusion during elevation of the auricle [3, 19] (fig. 5b). It is ideal when several blocks of 15 mm in height can be secured. Create a new space for embedding under the skin of the wound margin to make it easier to retrieve for subsequent surgeries.
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Fig. 5. a Harvesting rib cartilage. Harvest the 6th, 7th, and 8th rib cartilages from the right side for unilateral microtia and from the same side to reconstruction for bilateral microtia. b Creation of the framework (base frame, helix, and antihelix). Create a base frame with the 6th and 7th rib cartilages and use the lower margin of the 8th cartilage as the helix. Construct the antihelix using the portion where the curve of the ear concha is obtained (arrow 1). Make the portion from the intertragic notch to the tragus of the base frame by adding the remaining cartilage (arrow 2). Bank the medial side of the 6th and 7th cartilages (arrow 3). c Chiseling of the helix (8th rib cartilage). Use the scalpeled surface of the lower margin of the 8th cartilage as the contact surface with the base frame. Use the original edge to obtain the ridgeline of the helix. Chisel the inner surface of the helix with a woodcarving knife to make the cartilage pliable. Leave the ridgeline of the helix (arrow 1) and the contact surface with the base frame (arrow 2).
Creation of the Helix and Antihelix Cut the total length of the underside of the 8th rib cartilage about 5 mm from the margin with a scalpel for use as the helix. The surface resected with the scalpel is used as a bonding surface with the base frame, and to make the original edge of the lower line
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the portion from the intertragic notch to the tragus is required for lobule-type microtia, so it should be made by adding surplus cartilage (fig. 5b). A 38-gauge stainless wire suture with bilateral straight needles is used for joining cartilages. For unilateral microtia, the normal side is traced and reversed for use as a template. A framework is made about 1 mm smaller in circumference than the template, considering the thickness of the flap. For the same reason, allow an ample size for the cavity of concha and the intertragic notch. The base frame should be 4 mm thick so that the completed framework is less than 1 cm at the most. The upper anterior portion of the base frame leading to the crus of helix should be sloped to become thinner so the crus of helix is not higher than the base frame. Create the part of the lobule in order to have the width required only for making the silhouette of the intertragic notch and need to retain the softness of the lobule without inserting the cartilage too deeply in the lobule.
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as the helix ridgeline. The medial side of the 8th rib cartilage is usually a free end without a joint with the sternum, so the free end is used for the crus of helix. Cut the opposite costal end to taper so that the helix naturally disappears at the site of transition to the lobule. To make the cartilage pliable and to express the curly shape of the helix, make a groove on the inside of the helix with a round wood-carving chisel. At this time, retain the contact surface with the base frame and the original lower edge of the 8th rib cartilage, which will be the ridgeline of the helix (fig. 5b). Next, create the antihelix. Any of the remaining cartilage may be used, but select a portion yielding the curvature corresponding to the dike of the posterior wall of the ear concha (fig. 5b). Construct the inferior crus of the antihelix together with the triangular fossa by directly engraving on the base frame. Create the antihelix high enough so that the silhouette of the ear concha becomes obvious, and make the inner slope of the ridgeline steep whereas the outer slope should be gently chipped to make a natural scaphoid fossa. The end of the superior crus should be naturally tapered following the outer slope. Continue the lower end of the antihelix to the antitragus and create the antitragus as well (fig. 6).
Reconstruction of Auricle Kaga K, Asato H (eds): Microtia and Atresia – Combined Approach by Plastic and Otologic Surgery. Adv Otorhinolaryngol. Basel, Karger, 2014, vol 75, pp 61–75 (DOI: 10.1159/000350608)
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Fig. 6. Assembly of the framework. Provide ample space for the cavity of concha and the intertragic notch, and make the slope of the posterior wall of the ear concha steep up to the antihelix (arrow 1). Slant the portion of the base frame continuing to the crus of helix by thinning. Create the inferior crus of the antihelix by directly chiseling the base frame and make it lower than the superior crus (arrow 2). Fix the helix and antihelix over the base frame, and chisel the inner slant from the ridgeline of the antihelix sharply and the outer slant gently (arrow 3). Naturally taper the ends. Create the antitragus and the antihelix in a mass (arrow 4). Finally, chisel the base frame deeply to make the triangular fossa and scaphoid fossa, and make a suction hole on the bottom (arrows 5 and 6).
Fixation of the Helix and Antihelix Place the helix on the base frame and fix with a wire suture with bilateral needles from the end of lobule. Fix the end of the crus of helix at the back of the base frame. Insert the wire from the front side of the framework, twist it at the back, and fix it. Make slits in the cartilage surface to embed the wire to prevent it from being exposed. Next, fix the antihelix in the same manner. Creation of the Inferior Crus of the Antihelix, Triangular Fossa and Scaphoid Fossa To reconstruct the three-dimensional shape of the auricle, create the inferior crus by chiseling the base frame so that it is located below the superior crus and the crus of helix lower than that. After fixing the helix and the antihelix to the base frame, create the triangular fossa and scaphoid fossa with a wood-carving chisel, and open a suction hole at the base to adhere the skin flap and the rib cartilage framework with a suction drain [10] (fig. 6). Insertion of the Framework Insert a flat type J-VAC® drain (Johnson & Johnson K.K.) into the subcutaneous pocket before inserting the framework. Subcutaneously, place the drain tube as far away from the pocket as possible behind the ear to produce an airtight seal when suctioned. Then, insert the framework above the drain. Suture to fix the anterior peak of the helix and the tragus by covering them with subcutaneous tissues at the anterior border of the framework so that the silhouette of the anterior border of the helix and tragus does not stand out (fig. 7a). Given that the remnant lobule tends to migrate forward of the framework, insert the lower end of the framework into the small pocket under the skin of the lobule, and fix it with absorbable thread.
Dressing Avoid bolster fixation because it may suppress blood circulation in the flap. Continuously suction with a drain and stuff wet cotton into the ear concha, scaphoid fossa, and triangular fossa to prevent hematoma. Encircle the auricle with a doughnutshaped sponge to protect the reconstructed auricle from the pressure of a pillow.
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Suturing of the Skin Flap When suturing the skin flap, suction with the drain to adhere the flap and the framework while checking the contours of the auricle. To produce distinct contours, it is important to amply tuck in the flap into the dents of the ear concha, intertragic notch, scaphoid fossa, and triangular fossa. Trim the wrinkles and uneven skin covering the remnant cartilage as well as possible. Construct the tragus by wrapping the tragus portion of the framework with the anterior flap of the remnant auricle. At the intertragic notch, cut out the skin of the anterior lobule in a U-shape to match the shape of the framework, cut a fan-like slit into the flap of the subcutaneous pocket, and suture to make it deeper (fig. 7b).
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Fig. 7. a Insertion and fixation of the framework. Suture to fix the anterior apex of the helix (arrow 1) and the tragus (arrow 2) at the anterior border of the framework by covering with the subcutaneous tissues so that the contour of the anterior border does not protrude. b Suturing of the skin flap. Adhere the skin flap and the framework by suctioning with the drain, and trim the uneven skin covering the remnant cartilage as well as possible and the wrinkles remaining after tucking the skin flap into a dent (arrow 1). Dissect the skin of the lobular anterior in a U-shape at the intertragic notch, and make a fan-like slit into the skin flap to make it deeper (arrow 2). Create the tragus by wrapping the tragus of the framework with the skin flap (arrow 3).
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Reconstruction of Auricle Kaga K, Asato H (eds): Microtia and Atresia – Combined Approach by Plastic and Otologic Surgery. Adv Otorhinolaryngol. Basel, Karger, 2014, vol 75, pp 61–75 (DOI: 10.1159/000350608)
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Fig. 8. Design of the incision of the remnant auricle for small concha-type microtia. a Start the incision at the widest anterior-posterior diameter (arrow 1), and make a vertical incision to the ear concha for switch-back (arrow 2). b Design the subcutaneous pedicle inside the scheduled position of the ear concha (arrow 1), and design the incision of the posterior remnant auricle to course below it (arrow 2). a Anterior view. b Posterior view.
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Fig. 9. Switch-back of the lobule and resection of remnant cartilage in small concha-type microtia. a To provide a sufficient amount for switch-back, dissect the cartilage of the posterior wall of the ear concha by leaving the contour of the intertragic notch and antitragus (the portion inside the dotted line and shaded lines: arrow 1). Mark the point of switch-back where the shape of the intertragic notch appears the most natural (arrow 2). b Design to form a mild arc from the marked point for switch-back (arrow 1). Design a skin incision on the ridgeline of the remnant auricle as per lobulartype microtia (arrow 2). c Dissect the cartilage from the skin of the anterior auricle (arrow 1), and remove the cartilage inside the dotted line and diagonal lines by leaving the contour of the intertragic notch and antitragus (arrow 2). a Incision in the anterior remnant auricle and marking of the position of switch-back. b Incision in the posterior ear and design of resection of remnant cartilage. c Resection of the cartilage of the ear concha (enlargement of b shown from the incision on the back of the auricle).
Reconstruction of Small Concha-Type Microtia and Concha-Type Microtia
Designing the Position of Switch-Back and the Incision behind the Ear After the incision in the remnant auricle, mark a switch-back point to produce the shape of the intertragic notch as naturally as possible (fig. 9a). Design an incision line behind the ear to form a slight arch from that point (fig. 9b). Design a subcutaneous pedicle for small concha-type microtia in the same manner as for lobule-type micro-
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Kaji · Asato Kaga K, Asato H (eds): Microtia and Atresia – Combined Approach by Plastic and Otologic Surgery. Adv Otorhinolaryngol. Basel, Karger, 2014, vol 75, pp 61–75 (DOI: 10.1159/000350608)
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Incision of the Remnant Auricle The incision of the remnant auricle may vary depending on the amount of remnant auricle. As a guide, the incision is started at the widest diameter of the anterior-posterior dimension, and the lower region of the cavity of concha of the remnant auricle, or the region from the tragus, intertragic notch, and antitragus, is used for construction of the auricle. A vertical incision is made to the ear concha of the remnant auricle to enable sufficient switch-back. Resect the cartilage of the posterior wall of the ear concha by leaving the silhouette of the intertragic notch and antitragus to facilitate shifting (fig. 8, 9c).
Fig. 10. Creation of the framework. Create the framework basically in the same manner as for lobule-type microtia up to the antitragus.
tia (fig. 8b). Because the size of the required subcutaneous pocket varies depending on the amount of remnant auricle used for reconstruction of the auricle in the concha-type, determine the necessity of a subcutaneous pedicle as appropriate for each patient. Resection of Remnant Cartilage and Creation of a Subcutaneous Pocket The same techniques as for lobule-type are employed. Completely resect the remnant cartilage except for the portion used for reconstruction (fig. 9b). Creation of a Framework Similarly to the lobule-type, create a framework up to the antitragus using the 6th to the 8th rib cartilages (fig. 10). Bank the remaining cartilage under the skin of the chest.
Dressing To be done as for lobule-type.
Reconstruction of Auricle Kaga K, Asato H (eds): Microtia and Atresia – Combined Approach by Plastic and Otologic Surgery. Adv Otorhinolaryngol. Basel, Karger, 2014, vol 75, pp 61–75 (DOI: 10.1159/000350608)
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Joining the Framework with the Remnant Auricle and Wound Closure After inserting the suction drain, insert the framework into the subcutaneous pocket. Subcutaneously suture to fix the anterior margin of the crus of helix of the framework, place the cartilage of the antitragus of the remnant auricle over the antitragus of the framework, and suture with absorbable thread (fig. 11a). Trim the excess skin while suctioning with the drain and suture to close the wound (fig. 11b).
Suction drain
Suction drain
1 1 2 2
a
b
Fig. 11. Connecting the framework and remnant cartilage and suture of the skin flap. a Cover the subcutaneous tissue over the anterior apex of the helix at the anterior border of the framework and suture to fix (arrow 1). Overlay the antitragus of the remnant cartilage over the antitragus of the framework and suture with absorbable thread to fix them (arrow 2). b Adhere the skin flap and framework by suctioning with a drain, and trim the uneven skin covering the remnant cartilage as well as possible (arrows 1 and 2). a Fixation of framework and remnant cartilage. b Suturing of the skin flap.
Advances in auricular reconstruction by rib cartilage grafting have relied greatly on improvements in the framework. The most commonly employed methods are the Tanzer method, where a base frame is created with the 6th and 7th rib cartilages and the helix with the 8th rib [2, 5], and the Brent method [10, 11], which improved on the Tanzer method and has demonstrated stable results [5–7, 11, 12, 14–16]. We also consider it essential to only harvest these three rib cartilages and perform surgery when the patient’s chest circumference reaches 60 cm or more to permit harvesting of sufficient amounts of cartilage [7, 15, 16]. With respect to the shape of the framework, the helix and the center of the antihelix (posterior wall of the ear concha) should be higher, with emphasis placed on the depth of the scaphoid fossa, triangular fossa, and ear concha, to fully express the 3-dimensional structure of the auricle and its contours [6, 7, 9, 11, 15, 20]. However, the height should not exceed 10 mm at the most in consideration of vascular circulation in the flap of the subcutaneous pocket. A suction hole is opened onto the base frame of the scaphoid fossa and triangular fossa for continuous suction with a suction drain for 2 weeks after surgery [11]. Some consider a thick auricle to be unnatural [21], but it has been reported that it becomes thin and soft over long-term observation [15, 16], and we create a 4-mm thick base frame to prevent breakage. As a functional device for canalplasty, the curve of the ear concha is made larger and wider. This is because the opening of the EAC is made at a slightly upper posterior region relative to the normal position when the EAC is constructed
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Kaji · Asato Kaga K, Asato H (eds): Microtia and Atresia – Combined Approach by Plastic and Otologic Surgery. Adv Otorhinolaryngol. Basel, Karger, 2014, vol 75, pp 61–75 (DOI: 10.1159/000350608)
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Discussion
Reconstruction of Auricle Kaga K, Asato H (eds): Microtia and Atresia – Combined Approach by Plastic and Otologic Surgery. Adv Otorhinolaryngol. Basel, Karger, 2014, vol 75, pp 61–75 (DOI: 10.1159/000350608)
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via an approach to the tympanic cavity from the mastoid portion of the temporal bone, which is upper posterior to the temporomandibular joint via the mastoid air cells. By creating a wider ear concha, it is possible to widen the anastomotic site of the EAC and the ear concha during a joint surgery, which will be effective for improving auditory acuity and preventing post-operative stenosis [14]. Not only the shape of the framework, but also the site of its insertion is critical, and we position the ear concha to the mastoid portion of the temporal bone, which is posterior to the temporomandibular joint. A more natural appearance of the auricle is achieved by paying attention to both its shape and position [3, 5, 10]. In previous reports, prevention of forward rotation of the long axis of the auricle was considered the most important aspect with respect to the anterior-posterior dimensions [5, 10, 15]; in addition, in determining the position, we place emphasis on the functional aspect as well as considering the slant of the auricle [14]. In fact, the position of the auricle constructed by our method looks natural. Creation of the subcutaneous pocket is an important process requiring technique for expressing the contour. Tanzer [2] and Brent [10] performed transposition of the remnant lobule in separate stages to maintain the circulation of the flap , but it is possible to prevent necrosis of the flap by providing a subcutaneous pedicle as shown by Fukuda and others [3, 8, 16]. We continue the incision up to the upper pole along the ridgeline of the remnant auricle for resection of remnant cartilage, but have not experienced a skin necrosis complication considered due to the skin incision. Rather, skin necrosis is considered to occur because of tension when the size of the flap is not sufficient to cover the uneven framework [3, 16]. It is vital to preserve the subdermal vascular plexus during flap elevation [2, 3, 7, 10]. Tanzer [2] argued that it should be as thin as possible, whereas Fukuda [15] considered that resorption of cartilage is likely to occur after a few years and a wire may be exposed if it is too thin. Ogino [7] therefore recommends dissection at a thickness immediately below the skin where a small amount of fat is attached, and we use that layer when dissecting. The skin above the remnant cartilage may be necrotized subsequent to forceful dissection, but remnant cartilage can easily be resected openly and a flap can be elevated safely and at a consistent thickness with our method for making an incision up to the upper pole of the remnant auricle. In addition to skin necrosis and wire exposure, chest deformation at the site of harvesting the rib cartilage is considered a problem [22, 23]. It has been reported that chest deformation is unlikely to occur when patients are 7 years of age or older (or 10 years or older) [7, 15, 16, 22], so we perform surgery when patients are around 10 years of age. The perichondrium is preserved at the donor site to maintain the reproductive ability of the cartilage [24]. Some surgeons also harvest the perichondrium in expectation of the take and growth of the framework [3], but Fukuda [15] considered that the result would not be affected by the presence or absence of the perichondrium. Deformity of the chest wall may develop even when the perichondrium is preserved [23], and various methods have attempted to prevent this, such as preservation of the site of rib cartilage
transposition [12, 22], returning the extra cartilage to the donor site [24],and harvesting the rib cartilage by chiseling rather than in full thickness [25] (see ‘Chest Wall Deformity at the Site of Costal Cartilage Harvesting’, this vol., pp. 110–113). Further improvements need to be made in auricular reconstruction by rib cartilage graft, such as improvements in achieved auditory acuity, creative ideas for obtaining stable long-term results, and considerations for invasion to the donor site. Since the argument of Dunton’s group in 1964 that auricular reconstruction, which requires much labor but produces little fruit, should be abandoned and that attachment of an artificial ear would be best, some surgeons still select an artificial ear [1, 3]. However, it is natural for patients to feel that a prosthesis is not satisfactory [3]. Cronin reported auricular reconstruction using a silicone frame in 1966 as the material other than autologous tissues for support of the auricle, and it has been succeeded by Omori et al. [26]. However, many consider transplantation of autologous rib cartilage to be superior because a silicone frame is susceptible to trauma and easily exposed, relief from infection is difficult, and there may be anxiety associated with implantation of a foreign substance [1, 12, 15, 18]. Against this background, we who support auricular reconstruction by autologous rib cartilage graft should minimize invasion at the donor site and the number of surgeries, make shape and function compatible, and establish long-term stability. Details of our surgical procedure by rib cartilage graft aiming for compatibility of shape and function were explained above. Transplantation to mice of tissue-engineered bovine cartilage in the shape of a human ear was reported about 10 years ago [27], and application of the technology to humans was expected. Brent et al. [18] also performed independent research on a bioengineered framework, but clinical application is yet to be achieved. Despite the advances made in autologous rib cartilage grafting during the last half-century and on-going refinement efforts, we still have a long way to go before this new technique of tissue engineering becomes established in the clinical setting. There is no doubt that further advances in autologous rib cartilage grafting for auricular reconstruction are needed in the future.
1 Nishimura Y, Ogino Y: Historical and future reviews in ear reconstruction. Jpn J Plast Reconstr Surg 1974; 17:461–468. 2 Tanzer RC: Total reconstruction of the external ear. Plast Reconstr Surg 1959;23:1–15. 3 Fukuda O: Reconstruction of microtia. 1. The design of the proposed ear and the operative procedures of cartilage graft. Jpn J Plast Reconstr Surg 1974; 17: 469–483. 4 Fukuda O: Reconstruction of microtia. 2. The construction of cartilage framework. Jpn J Plast Reconstr Surg 1975;18:685–695.
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5 Tanzer RC: Total reconstruction of the auricle: the evolution of a plan of treatment. Plast Reconstr Surg 1971;47:523–533. 6 Spina V, Kamakura L, Psillakis JM: Total reconstruction of the ear in congenital microtia. Plast Reconstr Surg 1971;48:349–357. 7 Ogino Y: Total auricle reconstruction in cases of unilateral microtia. Jpn J Plast Reconstr Surg 1989; 32: 891–907. 8 Nagata S: A new method of total reconstruction of the auricle for microtia. Plast Reconstr Surg 1993;92: 187–201.
Kaji · Asato Kaga K, Asato H (eds): Microtia and Atresia – Combined Approach by Plastic and Otologic Surgery. Adv Otorhinolaryngol. Basel, Karger, 2014, vol 75, pp 61–75 (DOI: 10.1159/000350608)
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References
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Nobuyuki Kaji Department of Plastic Surgery, Dokkyo Medical University 880 Kitakobayashi, Mibu-Machi, Shimotsuga-gun Tochigi 320-0293 (Japan) E-Mail [email protected]
Reconstruction of Auricle Kaga K, Asato H (eds): Microtia and Atresia – Combined Approach by Plastic and Otologic Surgery. Adv Otorhinolaryngol. Basel, Karger, 2014, vol 75, pp 61–75 (DOI: 10.1159/000350608)
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