Weerda Surgery of the Auricle

Tumors - Trauma - Defects - Abnormalities
1. Auflage 2007
ISBN: 978-3-13-257847-0
Verlag: Thieme
Format: EPUB
Kopierschutz: 6 - ePub Watermark

E-Book, Englisch, 328 Seiten, ePub

Winner of the First Prize in ENT at the 2008 BMA (British Medical Association) Medical Book Competition

This book is a comprehensive guide to the delicate and complex reconstructive procedures for the external ear. Featuring concise descriptions, step-by-step instructions, and numerous before and after photos, this book provides surgeons with the essential knowledge that successful surgery in this difficult field demands.

The text opens with an overview of the anatomy and anthropometry of the external ear, aesthetic principles of auricular reconstruction, and the basic principles of plastic surgery. Separate sections of the book provide in-depth discussion of the techniques for managing tumors, trauma and non-inflammatory processes, auricular defects, and abnormalities.

Features:

• More than 1,300 illustrations and photographs that aid comprehension of auricular problems and surgical steps
• Detailed discussion of classification of auricular defects and abnormalities
• Coverage of the radiologic examination of malformations of the petrous temporal bone

An incomparable reference for all surgeons specializing in treating defects and disorders of the external ear, this volume succeeds beautifully in capturing the myriad creative, scientific, and technical facets of auricular reconstruction.

Hilko Weerda

Zielgruppe

Ärzte

Autoren/Hrsg.

Weerda, Hilko

Fachgebiete

• Medizin | Veterinärmedizin Medizin | Public Health | Pharmazie | Zahnmedizin Klinische und Innere Medizin HNO-Heilkunde, Phoniatrie, Audiologie

Inhaltsverzeichnis

1 Basic Principles
2 Tumors of the External Ear
3 Trauma and Non-inflammatory Processes
4 Classification and Surgery of Auricular Defects
5 Abnormalities
6 Diagnostics and Auxiliary Therapy
7 Epilogue
8 References
Appendix

Leseproben

1

1.1 Anatomy of the External Ear

The external ear () comprises the auricle (Fig. 1.1a, b) and the auditory canal.

The anterior surface of the ear is referred to as the anteroauricular (lateral, anterior auricular) surface, the posterior surface of the ear as the postauricular (medial, cranial, posterior auricular) surface (Rogers 1974).

The auricle consists of a skin envelope about 0.8–1.2 mm thick, which is firmly attached to the perichondrium (Fig. 1.2). The posterior surface bears an additional layer of fat between the skin and perichondrium, which, unlike the anterior surface, allows good mobility of the skin (1.2–3.0 mm) on the posterior surface (Smahel and Converse 1980).

The framework of the auricle (Fig. 1.3a, b) consists of a convoluted elastic cartilage, 1.0–3.0 mm thick.

Anterior auricular surface (Fig. 1.1a). The anterior relief of the auricle is characterized by its typical convolutions: the helix in the marginal region, the shell-like concha in the middle of the ear merging into the antihelix, which divides into an upper and lower crus. Between these lies the triangular fossa. The antihelix blends inferiorly into the anti-tragus, and between the tragus and antitragus lies the intertragal notch. For evolutionary reasons, there may be a small duplication above the tragus, which is referred to as the tubercle of His. Darwin's tubercle can be found in the superior portion of the helix, towards the scapha. The concha gives rise to the cartilaginous part of the external auditory canal.

Fig. 1.1 External ear and adjacent structures (after Weerda 1994 d). a Anterior auricular surface. b Posterior auricular surface.

Fig. 1.2 Histological structure of the auricle.

Fig. 1.3 Anterior view (a) and posterior view (b) of the elastic auricular cartilage (after Feneis 1982; Weerda 1985 a; Quatela and Cheney 1995).

Fig. 1.4 Arterial supply of the anterior (a) and posterior (b) auricular surface (after Weerda 1985 a).

The cartilaginous auditory canal extends into the bony part of the auditory canal, is about 3.5 cm long in all, and ends with the tympanic membrane. Note its proximity to the parotid gland anteriorly, as well as to the facial nerve, which courses in a lateral direction after emerging from the stylomastoid foramen and divides within the parotid (Davis 1987; Weerda 1994 d; see Figs. 1.1a; 1.15).

Posterior auricular surface. The posterior auricular surface (see Fig. 1.1b) is characterized by the eminences of the scapha, the triangular fossa, and the concha, between which are found the antihelical sulcus and fossa (see Fig. 1.1b).

Auricular cartilage. The cartilaginous relief of the anterior (see Fig. 1.3a) and the posterior surfaces (see Fig. 1.3b) corresponds to the structure of the anterior and posterior auricular surfaces. The earlobe lacks any elastic cartilage.

Vascular supply. Knowledge of the vascular supply of the external ear and the surrounding area is essential for auricular reconstruction (Rauber-Kopsch 1987; Park et al. 1992). The supply of the ear is based on two arteries: the superficial temporal and the posterior auricular (Fig. 1.4a, b). The anterior surface is supplied by numerous perforating vessels; the branches of the superficial temporal artery are most variable. The arteries have a diameter of between 0.4 and 0.7 mm, the veins between 0.3 and 2.0 mm.

Fig. 1.5 Sensory supply of the anterior auricular surface (a) and the posterior auricular surface (b; Quatela and Cheney 1995).

Fig. 1.6 Muscles and ligaments of the anterior (a) and posterior (b) auricular surface (after Davis 1987).

Sensory supply. The sensory supply of the anterior surface is via the auriculotemporal and great auricular nerves (Fig. 1.5a), the posterior surface by the great auricular nerve and the mastoid branch of the lesser occipital nerve (Fig. 1.5b; Quatela and Cheney 1995).

Muscles and ligaments. Although the muscles and ligaments play only a minor role for the human ear, the position of the large muscles, particularly the posterior auricular muscle and its corresponding artery, as well as the superior auricular muscle, should be known (Fig. 1.6a, b; Davis 1987).

Lymphatic drainage system. The draining basin of the external ear lies both superficially in the preauricular region in the parotid and in the submandibular region (Fig. 1.7a, lymph node groups 1, 2, 5, and 6) as well as in the postauricular and mastoid region (Fig. 1.7a, lymph node groups 3 and 4).

In the peripheral region, drainage is into the superficial lymph node groups and the deep cervical lymph node groups 7–11 (Fig. 1.7a, b).

Position. The position of the external ear plays an extremely important role in auricular reconstruction. The determination of its position, axis, etc. is discussed in the section on anthropometry (see p. 4), in the section on basic aesthetic principles (see p. 6) and in the section “Fabrication of a template” (see pp. 64, 202, 203).

Fig. 1.7 Superficial (a) and deep (b) lymph nodes (LNs) of the auricular region and the neck (after Feneis 1982; Richter and Feyerabend 1991).

Lymph node groups (see p. 3):

1 Preauricular LNs

2 Superficial parotid LNs

3 Infraauricular LNs

4 Occipital LN group

5 Mastoid (retroauricular) LNs

6 Deep parotid LNs

7 Intraglandular LNs

8 Superficial cervical LNs (external jugular vein)

9 Jugulodigastric LNs

10 Submandibular LNs

11 Retropharyngeal LNs

12 Superficial cervical LNs (carotid artery)

13 Lateral jugular LNs

14 Jugulomohyoideus LN

15 Supraclavicular LN group

1.2 Anthropometry of the Auricle

1.2.1 Introduction

Reconstructive and corrective surgery of the external ear requires exact knowledge of the normal auricular anatomy. This includes the position of the external ear with respect to the head and the relative positions of the various structures of its relief. These data, relative to the age, height, and sex of the patient, are required for individual surgical planning.

Classic cephalometry (measurement of the dimensions of the head) gained importance from the middle to the end of the last century. Farkas in the USA concerned herself with the specific anthropometry of the ear. In her classic work, she compiled a wealth of measurements gathered manually from volunteers and patients (Farkas 1981). We conducted our own study which, with the aid of a computer, digitalized and evaluated in detail standardized photographs of over 1000 normal and malformed ears (Kaesemann 1991; Siegert et al. 1998 b). In this chapter, the clinically most important standard anthropometric values (Tables 1.1 and 1.2), and sometimes their relationship to age and height, are presented as a basis for operative planning.

1.2.2 Variables Relative to Age and Height

The following variables are relative to age and, in particular, to height. The positions of important parameters will be described below.

When reconstructing the external ears of children and adolescents who are not yet fully grown, the expected body height should first be estimated. This can be calculated from the relative height in comparison with peers and from the height of the parents. A more exact method, which is not usually necessary for surgery of the external ear, is the analysis of growth using radiographs of the carpal bones.

Horizontal position of the ear. The horizontal position of the external ear increases almost linearly with height and is therefore related to head size. The symmetry of the head should also be taken into consideration in the clinical assessment of malformations. There may be considerable differences between the left and right side in combined malformations of the ear and lower jaw, so that the position of the ear cannot be determined strictly according to standard values, but will always be a compromise between the norm and individual asymmetry. For this purpose, the position of the readily palpable mandibular joint should be taken into consideration, situated as it is immediately in front of the tragus (see Fig. 1.11, p. 7).

Length of the auricle. The length of the external ear (Fig. 1.8a–c, Table 1.3) is closely related both to height and to age. Between the 5th year of life and adulthood it increases from 53 mm by...

Über Autor(innen)

Hilko Weerda