Nasal Reconstruction
Anatomy:
Blood Supply:
- Two major arteries that supply the external skin envelope to the nose:
- Lateral nasal artery – a branch off the angular artery which branches from the facial artery
- Columellar branches – off the superior labial artery a branch from the facial artery
- Blood Supply to the nasal tip
- From both the lateral nasal and columellar branches
- Blood supply to the nasal sidewall
- From the angular artery and lateral nasal arteries
*Blood supply to the septum is separate and from the sphenopalatine artery and the posterior ethmoid artery
Innervation:
- Anterior ethmoidal nerve – supplies sensation to skin of dorsum of lower nose and tip
- Infratrochlear nerve – supplies the sensation to the bridge and upper lateral nasal area
- Infraorbital nerve supplies skin on lower half of the nose
- Nasopalantine nerve – septum and anterior hard palate
Muscles:
- Levator labii superioris alaeque nasi – dilates the nares
- Depressor septi – depresses the nose and can cause tip depression with smiling
Internal Structure:
- Nasal Bones: form the upper structure and articulate with the upper lateral cartilage in the keystone area
- ULC: make up the midvault and contribute to the internal nasal valve
- LLC: paired alar cartilage that contains medial, middle, and lateral crura. These support the tip defining the shap, size and projection and contribute to the external nasal valve.
- Septum: formed by the perpendicular plate of the ethmoid bone, vomer, maxillary crest and the septal cartilage.
- Nasal Valves:
- Internal nasal valve: the is between the septum and the upper lateral cartilage. The internal nasal valve should be between 10-15degrees and contributes most of nasal air flow resistance
- External nasal valve: colloquially known as the nostril that is supported by the nasal ala and LLC
The nose is divided into thirds based on the underlying skeletal structure:
- proximal (over nasal bones)
- middle (lies over upper lateral cartilages)
- distal (includes nasal tip with paired alae over membranous septum), columella
9 Nasal Aesthetic Subunits:
- 2 nasal sidewalls
- Nasal dorsum
- 2 nasal ala
- 2 soft triangles
- Columella
- Nasal Tip
Nasal Defects:
Causes: These can be from trauma, Mohs surgery, or other cancer excisions
Often think through defects in a stepwise manner:
- What is missing?
- Defects can include soft tissue, structural support (cartilage) and lining –> need to think about all three when reconstructing a full thickness defect
- Where is the defect and how large?
- What nasal structure is deficient because this will drive you reconstructive options
Soft Tissue Only Defects:
- Small Defects:
- Healing by secondary intention: if the defect is <0.25 cm with intact perichondrium
- FTSG – this is especially useful for the upper 2/3 of the nose where there are not many local flap options
- Local Flap
- Bilobed flap:
- Used at the nasal dorsum, sidewall or tip for defects up to 1.5cm
- Maximum amount of rotation is 90-100 degrees (45-50 per lobe)
- Defect cannot involve the nasal ala
- Dorsal nasal flap:
- Used for the nasal dorsum for defects <2cm and must be 1cm away from alar rim and above tip defining points
- Blood supply: angular artery
- Cheek advancement flap:
- Can be used for defects up to 2.5 cm good in elderly patients (maximum angle of advancement is 100 degrees- 50 each)
- Nasolabial flap:
- Good for alar reconstruction, lateral sidewall, and when tunneled can be used for columellar reconstruction
- Maximum size 2cm
- Pedicle is based on the facial or labial artery perforators
- They can be inferiorly or superiorly based and require 2 stages (division and inset)
- When placed closed to alar margin they are frequently combined with non-anatomically placed concha cartilage graft to prevent notching
Small Composite Defects: Missing both Skin and Cartilage
- Chondrocutaneous composite flap:
- Maximum defect size is 1.5cm
- Typically harvested from the helical root
Large Defects:
Large Soft Tissue Defects: When you are missing a significant amount of skin (with or without underlying defects) a forehead flap is generally your best option for reconstruction:
- Forehead Flap:
- Vascular Supply: based on supratrochlear vessels
- Considerations:
- Dissection:
- Dissect initially in the subcutaneous plan and transition to the sub-frontalis plane in the mid forehead or start in the sub-frontalis plan from the start
- Transition to a subperiosteal plane above the supraorbital rim to protect the supratrochlear vessels from injury
- Maintain a pedicle of 10-12mm at the transition point
- Stages:
- 2-Stage: inset and then divide the flap
- Mennick 3 stage approach: (1) inset, minimal thinning, and cartilage placement (2) aggressive thinning (3) division of the flap
- Length of the Flap: if the patient has a low hairline, you may need to obliquely orient the flap or plan to remove some hair follicles from the columella
- Defect: the defects generally heal secondarily
Large Composite Defects:
- Options for Nasal Lining (this is the most important step in complex reconstruction)
- Hinged Mucoperichondrial flap for anterior ethmoidal artery
- Septal pivot flap: composite flap of mucosa and septal cartilage for both support and lining
- Folded forehead flap
- STSG to the undersurface of a forehead flap
- Options for Support:
- Septal cartilage
- Auricular cartilage
- Rib cartilage
Miscellaneous:
- Rhinophyma:
- characterized by progressive hypertrophy of sebaceous glands
- End stage presentation of rosacea
- Treatment includes, oral antibiotics, and surgical excision (tangential excision)