Part IV
Anatomy and Disease
of the Larynx and Head and Neck Surgery
Development:
Anatomy:
Classification
of the cartilage of the larynx
Single:
Thyroid cartilage: hyaline with ossification.
Cricoid cartilage: hyaline with ossification, signet ring.
Epiglottis: Fibro elastic cartilage, leaf like structure.
Joints:
Cricothyroid: synovial
Crico-arytenoid: synovial
Muscles:
Intrinsic:
Abductor (opened): posterior crico-arytenoid.
Abductor (closed):
Lateral cricoarytenoid.
Transverse portion of interarytenoid.
External portion of thyroarytenoid.
Tension:
Cricothyroid
Internal portion of vocalis (thyro-arytenoid)
Extrinsic:
Between the larynx and other structures.
Strap muscles
Sternothyroid muscle
Thyrohyoid.
Also inferior constrictor.
Nerve supply:
Superior laryngeal nerve.
Extrinsic: cricothyroid muscle.
Intrinsic: sensory supply to the larynx
Recurrent laryngeal nerve: all muscles except cricothyroid.
Compartment
of the larynx
Glottis: Vocal cord
Supragluttic: from the hyoid bone to the Vocal cord.
Subglottis: External from lower border of vocal cord to inferior border of the
cricoid.
Investigation of laryngeal
disease
History:
· Voice
problems:
Aphonia
Dysphonia
Hoarseness
of the voice
· Dysphagia.
· Pain:
refer to the ear.
· Shortness
of breath, strider.
Examination:
Inspection: for scars in the neck.
Indirect laryngoscopy: using curved mirror:
"open the mouth, pull the tongue out with
swabs, ask the patient to breath
through the mouth and to say Ah, Ah and then you would be able
to see the vocal cords.
Rigid endoscopy 70 degrees telescope: transoral
Fibre optic laryngoscopy: transnasal.
What to inspect:
Epiglottis, ventricles, vocal cords, ary-tenoid, subglottis if possible.
Investigation:
Lab:
F.B.C
T.F.T for any thyroid enlargement.
Radiology:
Plain X-ray: soft tissue neck
Chest X-ray.
CT scan: Both used in laryngeal
MRI scan: disease assessment.
Direct laryngoscopy: G.A.
Diseases of the larynx
Congenital: Infantile larynx is smaller, funnel shape, softer and higher in
the neck.
A. Congenital
laryngeal strider (laryngomalacia) commonest.
Abnormal flaccidity of the laryngeal cartilage.
Clinically: inspiratory strider.
Diagnosis: D.L, bronchoscopy.
Prognosis: Self limiting condition disappears by the age of
2.
B. Congenital
laryngeal web, atresia.
C. Congenital
subglottic stenois:
Normal subglottic diameter at birth 7mm
Subglottic stenois if diameter 3.5mm or less.
D. Congenital
laryngeal paralysis.
E. Subglottic haemangioma: presented with inspiratory strider. Treatment if big includes laser and tracheostomy.
Acquired:
I. pyrexial
(infection):
Auto epiglottitis
Acute laryngitis
Acute laryngeo tracheo bronchitis.
Acute epiglottitis:
Common in children than adults.
Aetiology:
H. influenza type B.
Clinically:
Painful throat, dysphagia, fever, muffled voice, unable to
breath while lying flat and having to sit to aid breathing.
Treatment:
Urgent admissions
obstructive air way problem.
Check O2
saturation with pulse oximetry.
IV antibiotics:
chloramphenicol, Amoxil.
Any doubt
with airway:
Intubation
OR
Tracheostomy.
Laryngotracheobronchitis:
Viral Parainfluenza
virus
Diseases into
subglottis, trachea, bronchi.
Treatment:
Humidification
Antibiotics
for secondary infection.
Fluids.
Intubation
if any respiratory difficulty: cyanosis, increased pulse
rate, increased respiratory rate, use accessory muscle.
II. Tumour
Benign:
Papilloma: infant viral in origin and multiple.
Adult single.
Adenoma.
Lipoma neurofibroma,
angioma.
Malignant:
Squameous cell carcinoma: commonest 95%.
Classification of laryngeal carcinoma:
Tis: carcinoma
in situ.
T1 a: carcinoma
limited to one side of the vocal cords.
T1 b: carcinoma
limited to 2 sides of the vocal cords.
T2: carcinoma
affecting 2 regions.
T3: fixations
of the vocal cords.
T4: tumour
outside the larynx.
Clinically:
Supraglottic: around 30%, early metastasis to the neck and rarely
presents
voice problems.
Dysphagia,
earache
Neck lump
Glottic: around
60%, husky voice (hoarseness).
Subglottic:
around 10%, husky voice, shortness of breath.
Investigation:
FBC CXR
CT
MRI
D.L and Biopsy
Treatment: Depends on the site and the classification of the
tumour in general
Radiotherapy
is the choice for:
T1, T2 and T3.
If any neck glands: then surgery (laryngectomy) and post operative
radiotherapy with neck dissection.
Other laryngeal carcinomas:
Adenocarcinoma,
adenoid cystic carcinomas, sarcoma, lymphomas.
Vocal cord
paralysis:
Unilateral:
Complete.
Incomplete.
Bilateral:
Incomplete.
Complete.
Aetiology:
1. Most cases the aetiology is unknown 30%.
2. Inflammatory T.B in lungs 13%
3. Neoplastic from base of the skull to the lungs 25%.
4. Trauma, iatrogenic
Diagnosis:
Clinically:
Voice change.
Strider.
Aspiration.
Investigation:
Blood
Scans to the
whole area.
Treatment:
Depends on the symptoms and the findings with
the investigations.
Neck masses and surgery
Congenital:
Cystic hygroma (lymphagioma)
Branchial cyst, sinus and fistula.
Acquired:
Inflammatory:
Salivary glands (sialadenitis).
Thyroid gland (thyroiditis).
Infected tlymph nodes: glandular fever, toxoplasmosis, CMV, cat scratch
Disease and T.B
Neoplastic:
Benign: skin tumours, caratid body tumour, neurogenic tumour.
Malignant: mainly metastasis from head and neck carcinomas.
Classification:
N0: No palpable nodes.
N1: 3cm
or less in diameter.
N2: a. 1 node
6cm or less.
b. multiple ipsilateral 6cm or less.
c. bilateral or contraleteral less than
6cm.
Treatment:
N1: radiotherapy or surgery.
N2: surgery and post op radiotherapy.
N3: palliative radiotherapy or surgery.
