Procedural Anatomy – Tubes

Master answer

Tracheostomy –  insertion of a tube through the anterior portion of the neck into the trachea to facilitate ventilation

Trachea Course:

• Larynx connects to the superior part of the trachea at C6 into the thorax and terminates at the level of the sternal angle, where it divides into the right and left mainstem bronchi. 
• Initially anterior, then moves posteriorly as it descends to move behind the sternal notch

Tracheal Structure:

• A fibrocartilaginous tube 10cm long, approx 5cm in neck
• Supported by incomplete cartilaginous tracheal rings, which keep the trachea patent.
• The tracheal rings are joined by fibroelastic tissue.
• They are deficient posteriorly where the trachea lies anterior to the oesophagus; the posterior gap is spanned by the involuntary smooth trachealis muscle

Relationships:

• Lateral – carotid sheaths (common carotid arteries, vagus and internal jugular veins), thyroid lobes, inferior thyroid arteries, recurrent laryngeal nerves
• Inferior to the isthmus of the thyroid gland are the inferior thyroid veins
• Posterior – oesophagus, vertebral column

Relevant surface anatomy (in midline of neck):

• Hyoid bone (at level of C3)
• Thyroid cartilage
• Cricothyroid membrane
• Cricoid cartilage (at level of C6)
• Thyroid gland
• Sternohyoid muscle just lateral to midline structures, overlies sternothyroid and thyrohyoid muscles

Layers of dissection in tracheostomy:

• Skin
• Subcutaneous tissue
• Fat
• Pretracheal fascia (superficial and deep)
• Passage through the fibroelastic tissue in between the 1st and 2nd rings (common in perc trache) or 2nd /3rd or 3rd/4^th (surgical trache)
• Trachea

Gladwin 2016

Answer by Gladwin