ENT

ENT / Otolaryngology.

[ENT @ENTEngland]

What is the relationship between the recurrent laryngeal nerve (RLN) and the common carotid artery (CCA) during a thyroidectomy?

[ENT @ENTEngland]

· The descending branch of the nerve travels between the deep and middle layers of the masseter muscle and angles toward the oral commissure.

[ENT @ENTEngland]

Identification of Masseteric Nerve.

· Found within the sub-zygomatic triangle bound by the zygomatic arch, frontal branch of the facial nerve, and the anterior temporomandibular joint.
· Can be localised to 3cm anterior to the tragus &1cm below the zygomatic arch.

[ENT @ENTEngland]

Calcium Bioavailability (BA).

Calcium Carbonate (CC)
• Alkaline
• BA 15-40%
• Low solubility, &inconsistent absorption rate

Calcium Citrate
• Acidic
• Requires less stomach acid for absorption
• BA~ 40%
• Absorbed 22% (empty stomach) to 27% (food) better than CC

[ENT @ENTEngland]

Head & Neck CUP Immunohistochemistry

• p16 - surrogate for HPV-associated oropharyngeal ca
• Epstein-Barr virus-encoded RNA, associated with nasopharyngeal ca
• Calcitonin for medullary thyroid ca
• Thyroid-transcription factor to distinguish from lung SCC (Lung is positive)

[ENT @ENTEngland]

• Overexpression of p16 is usually localised to tumour cell nuclei & cytoplasm
• p16 staining localised only to the cytoplasm is considered nonspecific and thus non-diagnostic.

(3/3)

[ENT @ENTEngland]

p16 testing and Head and Neck Cancer.

• Immunohistochemistry for over-expression of tumour suppressor protein p16 (cyclin-dependent kinase 2A) is a surrogate biomarker for HPV-mediated cancer
• HPV-E7 oncoprotein binds to Retinoblastoma blocking it from inactivating E2F

(1/3)

[ENT @ENTEngland]

• E2F upregulates p16 making it a marker for HPV induced cancers
• Not only is p16 a cheap and simple test to execute; it is an independent prognosticator of outcome
• p16 overexpression is diffuse (≥75%) tumour expression, with moderate (+2/3) staining intensity.

(2/3)

[ENT @ENTEngland]

ANSWER = RLN goes posterior to CCA.

[ENT @ENTEngland]

What is the relationship between the recurrent laryngeal nerve (RLN) and the common carotid artery (CCA) during a thyroidectomy?

[ENT @ENTEngland]

• Most commonly injured nerve in rhytidectomy is Great Auricular nerve.
• Emerges from the posterior border of the sternocleidomastoid muscle at a point 6.5 cm inferior to the external auditory meatus, also known as McKinney's point.

[ENT @ENTEngland]

Salvage laryngectomy complications

Hasan Z et al
Systematic review
Eur J Surg Oncol 2017

· 50 studies, n=3292
· Overall complication rate = 67.5%

· Pharyngocutaneous fistula (28.9%)
· Wound infection (14.1%)
· Pharyngeal stenosis (14.3%)
· Bleeding (5.9%)
· Dysphagia (18.6)

[ENT @ENTEngland]

ANSWER = TRUE.

The normal reference range for PTH is affected by Vitamin D and a comment on PTH should only be inferred following threshold achievement of Vitamin D (20-30ng/mL -dependent on source of guidelines).

[ENT @ENTEngland]

The normal reference range of parathyroid hormone is affected by Vitamin D depletion.

[ENT @ENTEngland]

Skeletal Actions of PTH

1. Immediate:
Mobilization of readily available calcium from skeletal stores.

2. Delayed:
Activation of bone resorption leading to more calcium and phosphate release.

(Talmage and Elliott 1958)

[ENT @ENTEngland]

Incidence of Laryngeal Malignancy in a 3-year follow up of laryngeal leukoplakia biopsies.

No dysplasia ~4%
Mild/moderate dysplasia ~ 10%
Severe dysplasia/carcinoma in situ ~18%

[ENT @ENTEngland]

Curative management considerations of locally advanced & metastatic cutaneous squamous cell carcinoma.

Claveau et al. 2020

[ENT @ENTEngland]

Transoral surgery.

Electrosurgical units have been shown to ignite and propagate fires at 15 W and when the fraction of inspired oxygen (FiO2) is greater than 50%.

[ENT @ENTEngland]

Distant metastasis (DM) in HPV positive oropharyngeal SCC.

• Overall DM rate is 7.0% (95% CI: 5.9–8.2)
• T3 or T4 disease associated with a 5-fold (95% CI: 1.92–12.40) risk of DM compared to T1 or T2 disease
• Most common sites: Lung (61%)>Abdomen>Skin

Crossley et al. 2022

[ENT @ENTEngland]

What is my risk of oropharyngeal HPV SCC?

D'Souza 2017

[ENT @ENTEngland]

At risk populations of oropharyngeal HPV SCC.

1. Sexual exposure to oral HPV (Men >5 lifetime oral sexual partners, Women >2)
2. Persistent oral HPV DNA
3. Persistent HPV E6 antibodies
4. Positive smoking status