p.5
Surgical Steps for Excision
What is the first step in the surgical procedure for excising a preauricular sinus?
Make a vertical elliptical skin incision around the sinus opening.
p.3
Surgical Anatomy and Risks
What should be done if the superficial temporal artery and vein are lacerated during surgery?
Bleeding can be controlled by ligating the vessel(s).
p.7
Surgical Indications and Procedures
What surgical approach is discussed in the study by Leopardi G et al.?
Supra-auricular approach for the surgical treatment of recurring preauricular sinus.
p.3
Histopathology of Preauricular Sinuses
What type of epithelium lines excised preauricular sinuses?
Stratified squamous epithelium.
p.5
Surgical Steps for Excision
What technique can be used to dissect down to the temporalis fascia?
Sharp dissection or electrocautery.
p.1
Surgical Anatomy and Risks
What risk is associated with misdiagnosing a 1st branchial cleft remnant as a preauricular sinus tract?
It may place the facial nerve at risk.
p.2
Embryology of the Auricle
What is the origin of the external auditory meatus?
It is derived from the 1st branchial cleft.
What are preauricular pits and sinuses?
Congenital anomalies located in or just in front of the ascending limb of the helix.
p.3
Surgical Anatomy and Risks
What is the risk associated with the frontal branch of the facial nerve during surgery?
Injury if the surgeon strays anteriorly during resection.
What technique is sometimes advocated to assist in identifying the sinus tract?
Injecting methylene blue into the cyst or sinus.
p.1
Preoperative Investigations
What should be done before contemplating surgery for an abscess?
The abscess should first be aspirated with a needle and treated with antibiotics.
p.2
Embryology of the Auricle
What can happen if the auricular hillocks do not fuse completely?
They may leave sinuses between them.
p.3
Surgical Anatomy and Risks
What anatomical structures must a surgeon be familiar with during the excision of preauricular sinuses?
Facial nerve, superficial temporal artery, and auricular cartilage.
p.4
Preoperative Investigations
When is CT or MRI imaging indicated for preoperative investigations?
When a sinus is atypically located or a branchial cleft remnant is suspected.
p.3
Recurrence Rates and Surgical Techniques
Why do some advocate for the removal of a small portion of auricular cartilage during excision?
To ensure thorough excision and reduce recurrence rates.
p.7
Histopathology of Preauricular Sinuses
What types of tissues are present in the specimen described?
Skin (S), soft tissue containing preauricular sinus (ST), and cartilage (C).
What may preauricular pits discharge?
Desquamated keratin debris.
What genetic trait is associated with preauricular sinuses?
Autosomal dominant trait with incomplete penetrance and variable expression.
p.1
Surgical Indications and Procedures
When is surgery indicated for preauricular sinuses?
When complicated by recurrent infection or abscesses.
p.5
Surgical Steps for Excision
What should be done after identifying the cartilage of the helix?
Dissect along the cartilage, keeping deep to the perichondrium.
p.5
Surgical Anatomy and Risks
What should be noted when extending the incision into the supra-auricular area?
The position of the facial nerve.
What is a potential issue with using a lacrimal probe during surgery?
It may cause a false tract and cannot identify small branches.
p.2
Embryology of the Auricle
What is a possible cause of the folding of ectoderm during auricle development?
It may be the cause of incomplete fusion of the hillocks.
p.4
Surgical Indications and Procedures
What are the steps taken to reduce recurrence in sinus surgery?
Operate under optimal conditions, completely excise the sinus tract with surrounding tissue, and ensure wide exposure.
p.4
Surgical Steps for Excision
What is the recommended incision approach for sinus surgery?
Supra-auricular extension of the preauricular incision.
p.6
Surgical Steps for Excision
What is the result of excising the slither of cartilage?
A surgical defect at the apex of the preauricular sinus.
p.3
Surgical Anatomy and Risks
Where do preauricular sinuses/cysts typically lie in relation to the facial nerve?
Superior and lateral to the facial nerve and parotid gland.
What syndrome may be associated with preauricular sinuses?
Branchio-oto-renal syndrome.
What should not be confused with a preauricular cyst?
A 1st branchial cleft remnant.
p.7
Histopathology of Preauricular Sinuses
What is the focus of the study by Dunham B et al. referenced in the document?
The histologic relationship of preauricular sinuses to auricular cartilage.
p.2
Embryology of the Auricle
Where are the most common sinuses located if the hillocks do not fuse?
Between the tragus and root of the helix, or between the antihelix and helix.
Which side are preauricular pits more commonly found?
More common on the right side, but may be bilateral.
p.5
Surgical Steps for Excision
In which direction should the soft tissues be dissected off the temporalis fascia?
In a posteroinferior direction.
p.2
Embryology of the Auricle
From which branchial arches do the auricular hillocks originate?
Numbers 1-3 originate from the 1st branchial arch and 4-6 from the 2nd arch.
What developmental issue can arise from anomalous development of hillocks 1-3?
It may cause supernumerary hillocks and preauricular tags.
p.5
Surgical Steps for Excision
What is the purpose of excising a slither of cartilage during the procedure?
To ensure complete removal of the preauricular sinus.
p.5
Surgical Steps for Excision
How should the wound be closed after the procedure?
Suture the wound in layers.
p.6
Surgical Steps for Excision
What is the first step in the dissection process described?
Dissecting along the temporalis fascia up to the cartilage of the helix.
p.6
Surgical Steps for Excision
What is being excised at the apex of the sinus tract?
A slither of helical cartilage.
p.6
Surgical Steps for Excision
What does the final part of the dissection include?
An island of helical cartilage.
