ENT Surgery: Scott-Brown's Otorhinolaryngology Preface

• The book is titled "Scott-Brown's Essential Otorhinolaryngology, Head & Neck Surgery"
• Edited by R James A England and Eamon Shamil
• Section Editors are Rajeev Mathew, Manohar Bance, Pavol Surda, Jemy Jose, Omar Hilmi, and Adam Donne
• Additional e-resources are available at www.scottbrownent.com
• The first edition was published in 2022 by CRC Press

Preface

• States the book is a concise summary of ENT surgery based on Scott-Brown's Otorhinolaryngology, Head & Neck Surgery 8e
• It can be used in clinics, wards, and operating rooms
• It is also suitable for a wide range of clinicians
• It is an abbreviated version of the 8th edition of the parent textbook

Companion Website

• Supplementary resources can be found at www.scottbrownent.com

Section 1: The Ear

• Chapter 1 covers the Anatomy and Physiology of Hearing
• Chapter 2 covers the Anatomy and Physiology of Balance
• Chapter 3 covers the Clinical Examination of the Ear and Hearing
• Chapter 4 covers the Psychoacoustic and Objective Assessment of Hearing
• Chapter 5 covers the Evaluation of Balance
• Chapter 6 covers Vestibular Disorders and Rehabilitation
• Chapter 7 covers Conditions of the External Ear
• Chapter 8 covers Eustachian Tube Dysfunction
• Chapter 9 covers Acute Otitis Media and Otitis Media with Effusion in Adults
• Chapter 10 covers Chronic Otitis Media
• Chapter 11 covers Ossiculoplasty and Myringoplasty
• Chapter 12 covers Otosclerosis
• Chapter 13 covers Bone Conduction and Middle Ear Implants
• Chapter 14 covers Sensorineural Hearing Loss
• Chapter 15 covers Tinnitus and Hyperacusis
• Chapter 16 covers Auditory Neuropathy Spectrum Disorder and Auditory Processing Disorder
• Chapter 17 covers Hearing Aids and Auditory Rehabilitation
• Chapter 18 covers Cochlear Implants and Auditory Brainstem Implants
• Chapter 19 covers Ear Trauma
• Chapter 20 covers Metabolic Bone Disease and Systеmic Disorders of the Temporal Bone
• Chapter 21 covers The Facial Nerve
• Chapter 22 covers Vestibular Schwannoma
• Chapter 23 covers Lesions of the Cerebellopontine Angle, Petrous Apex and Jugular Foramen
• Chapter 24 covers Temporal Bone Tumours

Section 2: Rhinology and Facial Plastic Surgery

• Chapter 25 covers Anatomy of the Nose and Paranasal Sinuses
• Chapter 26 covers Physiology of the Nose and Paranasal Sinuses
• Chapter 27 covers Nasal Airway Measurement
• Chapter 28 covers Outpatient Assessment
• Chapter 29 covers Imaging in Rhinology
• Chapter 30 covers Abnormalities of Smell
• Chapter 31 covers Allergic Rhinitis
• Chapter 32 covers Non-Allergic Rhinitis
• Chapter 33 covers Rhinosinusitis
• Chapter 34 covers Nasal Polyposis
• Chapter 35 covers Medical Management of CRS
• Chapter 36 covers Surgical Management of CRS
• Chapter 37 covers Complications of Rhinosinusitis
• Chapter 38 covers Nasal Airway Surgery: Management of Septal Deformities
• Chapter 39 covers Nasal Airway Surgery: Management of Enlarged Turbinates
• Chapter 40 covers Epistaxis
• Chapter 41 covers Nasal Fractures
• Chapter 42 covers Sinonasal Tumours
• Chapter 43 covers Extended Anterior Skull Base Approaches
• Chapter 44 covers Granulomatous Conditions of the Nose
• Chapter 45 covers Diagnosis and Management of Facial Pain
• Chapter 46 covers Pre-Assessment for Rhinoplasty
• Chapter 47 covers Rhinoplasty Following Nasal Trauma
• Chapter 48 covers External Rhinoplasty
• Chapter 49 covers Cosmetic Facial Interventions

Section 3: Head and Neck

• Chapter 50 covers Surgical Anatomy of the Neck
• Chapter 51 covers Etiology of Head and Neck Cancer
• Chapter 52 covers Molecular Biology and Gene Therapy
• Chapter 53 covers Imaging of the Neck
• Chapter 54 covers Management of Laryngotracheal Trauma
• Chapter 55 covers Pharyngitis
• Chapter 56 covers Upper Airway Obstruction and Tracheostomy
• Chapter 57 covers Voice Disorders and Laryngitis
• Chapter 58 covers Dysphagia and Aspiration
• Chapter 59 covers Salivary Gland Tumours
• Chapter 60 covers Parapharyngeal Space
• Chapter 61 covers Staging of Head and Neck Cancer
• Chapter 62 covers Laryngeal Malignancy
• Chapter 63 covers Hypopharynx
• Chapter 64 covers Oropharynx
• Chapter 65 covers Nasopharyngeal Carcinoma
• Chapter 66 covers Nasal and Sinus Malignancy
• Chapter 67 covers Benign and Malignant Disease of the Oral Cavity
• Chapter 68 covers Management of the Unknown Primary in Head and Neck Cancer
• Chapter 69 covers Metastatic Neck Disease
• Chapter 70 covers Prosthetic Management of Oral and Facial Defects
• Chapter 71 covers Grafts and Flaps in Head and Neck Reconstruction
• Chapter 72 covers Radiotherapy and Chemotherapy
• Chapter 73 covers Immunotherapy in Head and Neck Cancers
• Chapter 74 covers Quality of Life, Survivorship, and Outcomes in Head and Neck Cancer
• Chapter 75 covers Temporomandibular Joint Disorders

Section 4: Head and Neck Endocrine Surgery

• Chapter 76 covers Benign and Malignant Conditions of the Skin
• Chapter 77 covers Anatomy and Physiology of Head and Neck Endocrine Glands
• Chapter 78 covers Thyroid and Parathyroid Pathology
• Chapter 79 covers Endocrine Imaging
• Chapter 80 covers Evaluation and Investigation of Thyroid Disease
• Chapter 81 covers Benign Thyroid Disease
• Chapter 82 covers Management of Differentiated Thyroid Cancer
• Chapter 83 covers Management of Medullary Thyroid Cancer
• Chapter 84 covers Management of Anaplastic Thyroid Cancer and Lymphoma
• Chapter 85 covers Thyroidectomy
• Chapter 86 covers Surgery for Metastatic and Locally Advanced Thyroid Cancer
• Chapter 87 covers Investigation of Hypercalcaemia
• Chapter 88 covers Management of Hyperparathyroidism
• Chapter 89 covers Parathyroid Surgery
• Chapter 90 covers Medicolegal Aspects of Thyroid and Parathyroid Surgery
• Chapter 91 covers Evaluation and Investigation of Pituitary Disease
• Chapter 92 covers Primary Pituitary Disease
• Chapter 93 covers Management of Pituitary Disease

Section 5: Paediatric Otolaryngology

• Chapter 94 covers The Paediatric Consultation
• Chapter 95 covers Paediatric Anaesthesia
• Chapter 96 covers Hearing Testing
• Chapter 97 covers Management of the Hearing-Impaired Child
• Chapter 98 covers Otitis Media
• Chapter 99 covers Embryological Development Disorders
• Chapter 100 covers Imbalance
• Chapter 101 covers Nasal Obstruction
• Chapter 102 covers Rhinosinusitis and Lacrimal Disorders
• Chapter 103 covers Adenotonsillar Conditions and Obstructive Sleep Apnoea
• Chapter 104 covers Acquired Laryngotracheal Stenosis
• Chapter 105 covers Stridor
• Chapter 106 covers Foreign Bodies in the Ear, Nose and Throat
• Chapter 107 covers Childhood Malignancies, Cysts, and Sinuses of the Head and Neck
• Chapter 108 covers Drooling, Aspiration, and Oesophageal Problems
• Chapter 109 covers Paediatric Tracheostomy and Paediatric Airway Management
• Chapter 110 covers Pinnaplasty

Anatomy and Physiology of Hearing

External Ear:

• The auricle (pinna) exhibits a lateral surface with prominences and depressions
• It consists of elastic fibrocartilage, except for a band between the tragus and anterior crus
• The auricle gathers acoustic energy and directs it into the external auditory canal (EAC)
• It modifies sounds based on incident angle, aiding in sound localization
• Composed of cartilage in the lateral third and bone in the medial two-thirds
• It is lined with keratinizing squamous epithelium that moves desquamated cells, cerumen, and sebum
• Derives blood supply from the external carotid artery branches
• Undergoes venous draining into the external jugular, maxillary veins, and pterygoid plexus
• The lymphatic system contains nodes at the mastoid tip, pre-auricular and upper cervical nodes
• The EAC receives sensory innervation from the trigeminal, facial, and vagus nerves
• Innervation details of the pinna are shown in Figure 1.2

Middle Ear:

• Consists of the tympanic cavity (TC), Eustachian tube (ET), which is detailed in Chapter 8, and the mastoid air cell (MAC) system
• The MAC system is largely developed by the age of 6
• The mastoid antrum is an air-filled sinus within the petrous temporal bone

Tympanic Cavity (TC):

• It is bounded by the tympanic membrane (TM) laterally and the osseous labyrinth medially
• TM consists of the pars tensa and pars flaccida below and above the malleolar folds, respectively
• TM is composed of three layers: an outer epithelial layer, a middle fibrous layer (deficient in the pars flaccida), and an inner mucosal layer
• The auriculotemporal nerve, auricular branch of the vagus nerve (Arnold's nerve), and the tympanic branch of the glossopharyngeal nerve (Jacobsen's nerve) provide sensory innervation

Regions of the TC defined by mucosal folds:

• Known as the attic and located above the malleolar folds
• A bony crest, known as the cog, projects caudally, dividing it into posterior and anterior spaces
• Consisting of the part of the middle ear that is visible through the external canal with a microscope
• With a rounded elevation that occupies most of the medial wall and consisting of the basal turn of the cochlea
• Below the level of the inferior part of tympanic sulcus
• The floor is made of bony covering and should be kept in mind when raising the tympanomeatal flap
• Posterior to Mesotympanum
• Encloses the round window niche, which consists of 2 bony ridges

Protympanum:

• Anterior to the promontory and contiguous with the tympanic portion of the ET
• Includes the ossicular chain
• Connects the TM to the oval window via the malleus, incus, and stapes
• Includes the tensor tympani and the stapedius muscles, which stabilise the bones
• Tensor tympani is supplied by the mandibular nerve whereas the stapedius supplied by the facial nerve
• Contains the nerves
• A branch of the facial nerve
• Runs across the medial surface of the TM between the fibrous layers and the mucosal
• The tympanic plexus is formed by Jacobsen's nerve and caroticotympanic nerves
• Mucosa consists of ciliated respiratory mucosa that coalesce at the tympanic orifice of the ET

Inner Ear:

• Delivers sensory information relating to both hearing and balance
• Composed of a dense bony covering, membranous ducts, and sensory organs

The three main components of the inner ear include:

• Otic capsule or bony labyrinth
• Membranous ducts
• Sensory organs inside the ducts

Other facts about Inner Ear:

• Space between bony and membranous labyrinth filled with perilymph composed of high concentrations of sodium and low potassium
• Communicates variably with the cerebrospinal fluid via the cochlear aqueduct
• A fluid filled membranous labyrinth that is composed of high potassium and low sodium

Cochlea:

• Consists of three scalae (vestibula, media, and tympani) coiled in a spiral around modiolus in two and a half turns
• Scala vestibuli and scala tympani are filled with perilymph
• The central scala media (SM) is filled with endolymph
• Contained stem is the sensory epithelium, the Organ of Corti
• Strip of supporting and sensory cells, including inner and outer hair cells, resting upon a basilar membrane
• Contains the gelatinous tectorial membrane that is essential for hearing mechanics
• Contains the stria vascularis that aids with ion transportation and forms lateral wall of the SM

Organ of Corti:

• Contains the cylindrical-shaped outer hair cells (OHCs) and goblet-shaped inner hair cells (IHCs)
• There are four times more OHCs (three rows) compared with IHCs (one row)
• IHCs are primary receptor cell, innervated by the majority of cochlear afferent nerves
• OHCs play in efferent and modulating role, which responds to BM motion
• Modulates signal and improve frequency selectivity reaching the IHCs
• Consists of motile microvilli-like structures called stereocilia, that in turn increase height in particular direction
• The spiral ganglion collects cell bodies from afferent nerve fibres

Spiral Ganglion:

• Contains type 1 neurons (myelinated)
• Innervate IHCs, have large diameters
• Consist of 95% of the nerve fibre population
• One type 1 fibre innervates one IHC
• One IHC may synapse with several nerve fibres
• Contains type 2 neurons (unmyelinated)
• Innervates OHCs and are smaller than type 1 neurons
• One type 2 fibre innervates many OHCs

Auditory pathway involves:

• Spiral ganglion central axons projecting via the cochlear nerve into the brainstem
• Information conveyed bilaterally to the superior olivary nuclei (SON)
• Lateral lemniscus and inferior colliculus of the midbrain
• Medial geniculate nucleus of the thalamus
• Primary auditory cortex in the Sylvian fissure of the temporal lobe
• Connections from the SON to facial nuclei that help mediate the stapedius reflex
• Efferent Auditory pathway arises in the lateral olive

Embryology of the ear:

• Evelops from the hillocks of the first and second pharyngeal arches
• Abnormalities of the pinna can indicate abnormalities of other first and second arch derivatives
• EAC develops from the ectoderm of the first branchial groove
• ET and middle ear come from the second branchial pouch
• Otic capsule develops from the mesoderm
• Menbranous labyrinth develops from ectodermal thickening
• It forms around 25 weeks and reaches complete development to an adult state

Physiology of Hearing:

• Human ear is capable of hearing frequencies of 2–20 kHz and intensities up to 120 dB
• Sound waves reflect into the ear canal then travel to the EAC to undergo a resonance boost around 2.5 and 3.5 kHz
• Middle ear converts from the low-impendence high-velocity to high-impedence fluid in the cochlea by about 18:1
• Stapedial muscles tense to stiffen sounds that enter the cochlea and provide reflex in order to protect from high altitude sounds
• Cochlear travelling then travels to the BM where specific parts interpret the different sound types in different areas

Anatomy and Physiology of Balance

Bony Labyrinthine Anatomy:

• The bony labyrinth within the petrous temporal bone and contains, cochlea, vestibule, and semicircular canals
• medial section is a vestibule that is connected to a vestibular acqueduct and displays two openings.
• On one limb is common curus and ampulla
• arranged in a perpendicular axis that connects to the otic fluid and causes rotational forces within the fluid

Keypoints about the Balance system:

• The superior and posterior are located and measured from the sagittal perspective
• Contains ducted anatomy, with the ducts leading into all primary points in measurement
• Inner fluids are postassiumrich and connect to the hair cells that control measurements in the duct system

Endolymphatic fluid controls:

• Lying on both sides for measurement and analysis for the brain to understand how the ear is tilting
• The utricle connects to the saccule but the saccule is close to the stapes, with connections to the fluid The endolymphatic allows connection to the spinal fluid, and helps relay balance

Clinical Examination of the Ear and Hearing

Steps for Clinical examination:

• View for scars
• Perform Otoscopy to gain a wider view of the ear canal and tympanic membrane:
• Shine a light and pull back or upward on the ear to best visualise its contents
• Micro or traditional view methods

Understanding the Membrane:

• Identify the Handle of membrane, the umbo,and visualise parts tensa and flaccida
• Ensure to understand the angle of malleus and its position
• The examiner should watch out for shorteness that the area lacks proper tension and can lead to perforation as the head moves

General notes:

• Test the bone vibrations
• Use tunning forks but the quality can be affected by the vibration of the bone and the area of the mastoid where it is located
• Weber Test
• To be done with testing asymmetry
• In the middle on a midline suture to compare the ear canal dominance

Audiometry test:

• Test 1000HZ at various dBs to better understand volume and the hearing limits for the ear