------------------------------------------------------------------------------- TITLE: AURICULAR RECONSTRUCTION SOURCE: Dept. of Otolaryngology, UTMB, Grand Rounds DATE: January 3, 1996 RESIDENT PHYSICIAN: Rusty Stevens, M.D. FACULTY: Karen H. Calhoun, M.D. SERIES EDITOR: Francis B. Quinn, Jr., M.D. ------------------------------------------------------------------------------- "This material was prepared by resident physicians in partial fulfillment of educational requirements established for the Postgraduate Training Program of the UTMB Department of Otolaryngology/Head and Neck Surgery and was not intended for clinical use in its present form. It was prepared for the purpose of stimulating group discussion in a conference setting. No warranties, either express or implied, are made with respect to its accuracy, completeness, or timeliness. The material does not necessarily reflect the current or past opinions of members of the UTMB faculty and should not be used for purposes of diagnosis or treatment without consulting appropriate literature sources and informed professional opinion." INTRODUCTION Reconstruction of auricular defects can be challenging for a variety of reasons. The prominent position of the auricle ensures that any asymmetries in size, shape or position will be easily noticed. Additionally, the complex cartilage folds and thin, adherent skin are difficult to reproduce. It is therefore important to have a complete understanding of the available reconstructive options. ANATOMY The auricle is a complex cartilaginous structure with multiple folds, draped closely with thin skin. The major landmarks include the helix, antihelix, tragus, antitragus, scaphoid fossa, triangular fossa, concha and lobule. Anteriorly, the skin has little subcutaneous tissue and is closely adherent to the cartilage. Inferiorly, the amount of subcutaneous tissue increases and cartilage decreases to end in a lobule that is primarily skin and subcutaneous tissue. Posteriorly the skin is much less adherent to the cartilage. Blood supply to the region is important from a surgical standpoint and includes the postauricular branch of the external carotid artery which supplies most of the posterior aspect and a small amount of the anterior auricle. Additionally, the occipital artery gives off a branch which supplies part of the posterior auricle. The anterior blood supply primarily is from the anterior auricular branch of the superficial temporal artery. Sensory innervation is supplied by the greater auricular, and lesser occipital nerves from the cervical plexus as well as the auriculotemporal branch of the trigeminal nerve and the auricular branch of the vagus nerve. Both extrinsic (Auricularis anterior, superior, posterior) and intrinsic muscles are present but serve little or no function in humans. GENERAL CONSIDERATIONS As a general rule, if the original parts are available and salvageable, these will give the best final outcome. Even a near total avulsion may be salvaged by primary reattachment if a small pedicle of soft tissue remains.(1) Meticulous debridement and close observation for infection, ischemia or venous congestion are particularly important in these cases. Additionally, pre-operative considerations include age, general health, radiation exposure or tobacco use as well as a complete evaluation for associated injuries or evidence of residual or recurrent tumor. Above all, the available options and a realistic assessment of the likely outcome should be discussed with the patient at length prior to reconstructive surgery. PARTIAL DEFECTS Rim Defects Rim defects can be repaired primarily with a rim advancement flap.(6) This is a single stage procedure that usually produces excellent results. A full thickness incision is made in the helical fold from the inferior aspect of the defect down to the upper portion of the lobule. The rim is then advanced and closed primarily. Because the lobule is expansile, there is usually only minimal deformity produced. Larger defects can be repaired using tubed pedicled flaps.(5,9) These are staged procedures and leave a scar at the donor site but will also give acceptable results. The initial procedure involves elevating and tubing a bipedicled flap. The donor site may be located in the pre or postauricular region or in the neck. The flap width is determined by the defect size and the length may be up to six times the width. A central, third pedicle may be preserved if longer lengths are required or there is concern for the flaps viability. Successive procedures are performed at 2-3 week intervals to divide each pedicle and transfer that portion of the flap to the auricle. Conchal Defects Conchal defects involving the anterior skin and cartilage can be repaired with a postauricular "revolving door" island flap.(6) The skin island includes posterior conchal as well as postauricular skin and is elevated anteriorly and posteriorly to leave a pedicle in the conchal-mastoid groove. The "revolving door" is then rotated anteriorly into the conchal defect. The post auricular donor site can be closed primarily. Full thickness conchal defects can be closed using a pedicled myocutaneous flap based on the post auricular artery.7 Skin islands up to 6 x 6 cm can be developed with this technique. The vascular pedicle is protected by elevating the flap in a subperiosteal plane and only elevating it superiorly and posteriorly. The auricle is pulled down to the flap and the donor site is closed primarily. Upper Third Defects The upper third of the auricle can be reconstructed using a staged procedure that involves harvesting costal cartilage to replace the lost rim. After cutting this cartilage to an appropriate size, it is sutured to the remaining helical rim and then buried in the adjacent postauricular skin. In 3-4 weeks, an incision is made approximately O.5 cm above the cartilage and it is elevated. The posterior aspect is either allowed to heal secondarily or a Split thickness skin graft is applied.(9) Middle Third Defects The middle third can be repaired with costal cartilage in a staged procedure similar to that described for the upper third. An alternative method is described by Jackson that uses the bulk of a posteriorly based, postauricular flap. This flap is elevated and sutured to the anterior aspect of the defect. In a delayed fashion, the pedicle is divided and the posterior portion of the flap is folded to resurface the posterior aspect of the auricle. The donor site is allowed to heal secondarily or is covered with a skin graft. Lobule Defects Naumann describes two techniques to reconstruct lobule defects. The first is a single stage reconstruction that uses an inferiorly based, elliptical transposition flap. The width of the flap is twice that of the desired lobe length. After elevating the flap, it is folded, rotated posteriorly and inset into the lobule remnant bed. The donor site is easily closed primarily. The second technique requires two stages. First the lobule remnant is inset into the post auricular skin at its edge. Three to four weeks later a flap is elevated posteriorly and inferiorly with its base at the lobule. The posterior portion is folded underneath to become the medial aspect of the lobe and the inferior edges are approximated to free the lobe from the mastoid skin. The donor site is closed by a local advancement flap or skin graft. TOTAL AURICULAR DEFECTS As mentioned above, the original structures should be utilized if at all possible. In the case of complete avulsion injury, if the ear is transported with the patient in a timely fashion, and the surgeon is skilled at microvascular techniques, these may be employed to primarily reattach the auricle. Chalain and Jones report success in such a case where a single arterial anastomosis was made and medicinal leeches were used until intrinsic venous outflow was established (9 days).(1) If immediate reattachment is not possible, the cartilaginous framework can often be salvaged and the auricle reconstructed in a delayed fashion by debriding the skin and lodging the cartilage in a subcutaneous pocket either locally or at a distant site (i.e. forearm).(10) The final reconstruction is performed at a later date by either elevating the cartilage and skin grafting the posterior aspect or microvascular transfer. Staged procedures utilizing temporalis and temporoparietal fascial flaps to cover the cartilage have also been described.(2,6) In cases where the entire auricular structure is lost (either trauma or tumor), the standard reconstruction is a staged procedure similar to that used for microtia malformation. Contralateral costal cartilage is initially harvested, carved and placed in a subcutaneous pocket. Later procedures attempt to reconstruct the lobule and tragus, and finally elevate the reconstructed auricle away from the scalp. An alternative procedure described by Costa et al. involves implanting a silastic mold into the forearm to form a prefabricated flap. Later microvascular techniques are used to transfer the mold and forearm skin to the head. Finally, the use of a prosthetic auricle is a viable option in some patients and will be discussed later. TISSUE EXPANDERS Tissue expanders have been widely used in reconstructive surgery and are particularly helpful in combination with many of the above mentioned techniques. A postauricular crescent shaped expander can be used to increase the amount of thin non hair-bearing skin in this region. The expansion of skin also promotes ingrowth of new vessels which may improve flaps viability. However, a dense capsule usually forms around the expander and this may limit the flexibility of the tissue or blunt the contours of the underlying cartilage. The capsule can be excised but this is difficult and may injure the delicate microvasculature of the flap.(8) PROSTHETICS The use of auricular prostheses is an option that should be considered and for many patients may be the reconstruction of choice. Disadvantages include need for daily care and injury to adjacent skin either from direct contact or from the strong adhesives needed to hold the prosthesis in place. Osseointegrated implants have recently been used with success but also have problems related to local injury, daily care and availability.(11) CONCLUSION Reconstruction of the injured or surgically resected auricle can be difficult. Initially, attempts to salvage as many of the native structures as possible are of utmost importance. A variety of techniques can later be employed to reform the lost structures or replace the entire auricle if necessary. -------------------------------------------------------------------------- BIBLIOGRAPHY 1. Chalain, T.d., Jones, G. Replantation of the avulsed pinna: 100 percent survival with a single arterial anastomosis and substitution of leeches for a venous anastomosis. Plast. and Recon. Surg. 1995;95(7):1275-79 2. Cheney, M.L., Varvares, M.A., Nadol, J.B. The temporoparietal fascial flap in head and neck reconstrucion. Arch Otolaryngol Head Neck Surg. 1993;119:618-23 3. Costa, H., Cunha, C., Guimaraes, I., Comba, S., Malta, A., and Lopes, A. Prefabricated flaps for the head and neck: a preliminary report. British J. of Plast. Surg. 1993;46:223-7 4. Destro, M.W., Speranzini, M.B. Total reconstruction of the auricle after traumatic amputation. Plast. and Recon. Surg. 1994;94(6):859-864 5. Dujon, D.G., Bowditch, M. The thin tube pedicle: a valuable technique in auricular reconstruction after trama. Br. J. of Plast. Surg. 1995;48:35-38 6. Jackson, I.T. Local Flaps in Head and Neck Reconstruction. Mosby, St. Louis. 251-271. 1985 7. Krespi, Y.P., and Pate, B.R. Auricular Reconstruction using Postauricular Myocutaneous Flap. Laryngoscope 1994;104:778-780 8. McIvor, N.P., Fong, M.W., Berger, K.J., and Freeman, J.L. Use of Tissue Expansion in Head and Neck Reconstruction. J. of Otolary. 1994;23(1):46-49 9. Naumann, H.H. Head and Neck Surgery: Indications, Techniques, Pitfalls. Saunders, Philadelphia. 31-69. 1982 10. Schiavon, M., Cagnoni, G. Salvage of an amputated ear temporarily lodged in a forearm. Plast. and Recon. Surg. 1995;96(7):1698-1701 11. Wilkes, G.H., Wolfaardt, J.F., Dent, M. Osseointegrated alloplastic versus autogenous ear reconstruction: criteria for treatment selection. Plast. and Recon. Surg. 1994;93(5):967-979 --------------------------------------------------------------------------- TEST QUESTIONS - The following test questions are intended to provide proof to accrediting agencies that you have read and understood the entire Grand Rounds element. Your answers should be based on the text of the Grand Rounds element. Answers should be sent by e-mail addressed to fbquinn@utmb.edu. Answers can be sent by U.S Postal Service mail, using a plain sheet of paper on which the Grand Rounds element and the subscriber are fully identified. Correct answers will be transmitted to the subscriber via e-mail on request. Comments and alternative points of view should be expressed at the end of the list of the subscriber's answers. E-mail answers can be submitted thus: AURICULAR RECONSTRUCTION_96 1b, 2c, 3b, 4a, 5c, 6b, 7d, 8c, 9a, 10a yes, yes, yes, no, yes, ?, yes, ?, 50 cents The University of Texas Medical Branch (UTMB) is accredited by the Accreditation Council For Continuing Medical Education (ACCME) to sponsor continuing medical education for physicians. UTME designates this continuing medical education activity for 1 credit hour in Category 1 of the Physicians's Recognition Award of the American Medical Association. 1. List six major landmarks of the auricle. _________________, _________________, _________________ _________________, _________________, _________________ 2. Primary anterior blood supply- _______________________ Primary posterior blood supply- _______________________ 3. List two methods of reconstructing a rim defect. _____________________________ _____________________________ 4. True/False Conchal defects always require cartilage reconstruction. Middle 1/3 defects always require cartilage. 5. List 2 possible options for the completely avulsed auricle brought into the ER in a timely fashion. _________________________ _________________________ 6. Two problems associated with prosthetic auricles are- _________________________ _________________________ 7. The main disadvantage of tissue expanders is- __________________________ 8. After reattachment of a partially avulsed auricle or any significant auricular reconstruction, three important complications that should be watched for include- __________________________ __________________________ __________________________ In order for the sponsors of this CME activity to monitor its usefulness and appropriateness to subscribers, we ask that you supply answers to the following questions concerning the accompanying Grand Rounds Online CME segment: 1. Was the presentation organized in an acceptable manner? yes no opinion no 2. Was the material adequate to your continuing education needs with respect to content? yes no opinion no 3. Was the material appropriate to your clinical practice needs? yes no opinion no 4. Did you feel that the discussants' remarks were responsive to the issues presented in the body of the Grand Rounds segment? yes no opinion no 5. Do you consider the presentation to be timely with regard to current information available in both the lay press and the professional literature? yes no opinion no 6. Are the questions submitted with the Grand Rounds element meaningful in that they stimulate thought and perhaps further inquiry? yes no opinion no 7. Is the method of submitting the subscriber's answers to these questions expeditious and convenient? yes no opinion no 8. Would you recommend this method of completing the general requirment for Continuing Education Activity to your colleagues? yes no opinion no 10. How much money (U.S. dollars) would you be willing to pay for each award of 10 or more CME Category I credits earned through this type of online CME activity? $100 $50 $25 $12.50 $6.25 $3.00 $1.50 $0.75 $0.35 $0.15 Please submit any comments, criticisms and suggestions which you may have in the space below. They will be given thoughtful consideration, especially if they are favorable comments, gentle criticisms, or constructive suggestions. 8-) (_____) /s/ The Editor. ;-) Francis B. Quinn, Jr., M.D. University of Texas Medical Branch Dept. of Otolaryngology Galveston, TX 77555-0521 Internet addresses: 409-772-2706, 772-2701 fbquinn@UTMB.edu 409-772-1715 FAX fbquinn@phil.utmb.edu -----------------------------END----------------------------------------