Excisions Flashcards
What is the optimal apical angle (in degrees) for the vertices of a fusiform excision?
≤30 degrees (avoids formation of standing cons)
What is the optimal length to width ratio for an excision?
≥3:1
What is a crescent excision and what locations is it good for?
One side is longer than the other, leading to a curved line when closed. This good for areas with curved relaxed tension lines (cheek and chin)
What is a M-plasty and what is it useful for?
This is where on one side of the eclipse, instead of an elipse two small tringles extend from the circular central defect. When closed this looks like an “M.” Because the lines don’t extend all the way as a fusiform excision this is for shortening the scar
- Good for free margins like the perioral and periocular areas
What is an “S-plasty” what does it do to the length of the excision, and what is its use?
Increases the length of the scar (creates a lazy S shape) but the overall length (end to end) is the same. This redistributes the tension along different vectors and decreases tension in the central portion of the scar
- This decreases risk of a depressed scar and decreases risk of dehiscence and contraction
What locations tend to be good for a S-plasty?
Convex surfaces
Examples: forearm, shin, and excision that cross over a joint
When should a wedge excision be used on the lower lip?
Full-thickness excision of the lip for defects up to 1/3 the length of the lower lip
What must be marked prior to doing a wedge excision?
The vermillion border prior to closure!
This is a must to make sure the realignment is precise
What is the order of closing a wedge excision of the iip?
- Submucosal layer using silk or polyglactin 910 (bury knots away from oral cavity)
- Orbicularis oris muscle, use polyglactin 910 (maintains competence of oral sphincter
- Dermis and subcutaneous layers, use polyglactin 910 (start at the vermillion-cutaneous border)
- epidermis: Use nylon w/ hyper-eversion to prevent depressed scar
What are the options for repairing a standing cone?
Extend the incision, M-plasty, excision of a Burow’s triangle, rule of halves
What are the most common causes of standing cones (“dog ears”)?
Apical angles too wide (>30 degrees) length to width ratio too low (<3:1), unequal lengths on each side of the wound, convex surfaces, and insufficient undermining at the wound edge
What are 4 options for standing cone repair options?
- Extending the incision line
- M-plasty
- Rule of halves
- Excision of Burow-s triangle
In what plane should undermining occur in the trunk or extremities?
Mid-deep fat (for small/standard excisions)
Just above deep fascia for larger lesions/deeper melanoma
In general, what is the undermining plane on the face?
In general, undermining should occur superficially to the SMAS (superficial subcutaneous plan)
b/c motor nerves are in or deep to the SMAS usually
What is the optimal undermining plane on the cheek?
Mid subcutaneous plan (avoid transecting parotid duct, buccal and zygomatic branches of CN7, and vascular structures)
What is the optimal undermining plane on the ear?
Dissection is always just above the perichondrium because there is virtually no fat/subcutis
Where should you undermine for the eyebrow?
In the subcutis, must be deep to the hair follicles to avoid hair loss
What is the plan of undermining for the eyelid?
Right above the obicularis oculi muscle (very minimal subcutaneous tissue)
What is the optimal undermining plane for the forehead?
Deep subcutaneous plane, just above the frontalis muscle for shallow wounds
Subgaleal (rare) for larger or deep wounds (more likely to affect sensory nevers)
What is the optimal undermining plane of the nose?
Submuscular fascia/periosteum/perichondrium (deep to the SMAS/nasalis muscle)
This is a relatively avascular plane
What is the optimal undermining plane in the lateral neck?
Superficial subcutaneous plane, avoids Erb’s point or accessory never
What is the optimal undermining plane of the lip?
Above the orbicularis oris muscle (avoid cutting into the orbicularis muscle as it is vascular and can cut the branches of the labial artery)
What is the optimal undermining plane for the mandible area?
The superficial subcutaneous plane, above the marginal mandibular nerve
What is the optimal undermining plane of the scalp?
Subgaleal plane (avascular)
What is the optimal undermining plane on the temple?
The superficial subcutaneous plane
Avoids the transection of the temporal branch of the facial nerve and the temporal artery
What is the timeline for wound strength out to one year?
1 week = 5%
2 weeks = 10%
4 weeks = 40%
1 year = 80% (max)
What are the margins for melanoma in situ?
0.5cm-1cm
What is the margin for a melanoma w/ a Breslow depth <1mm?
1cm WLE to the deep fat or fascia
What are the recommended margins for melanoma that is 1-2mm Breslow depth?
1-2cm w/ WLE to the fascia
What is the margins for melanomas >2mm?
2cm WLE to the fascia
What is the margins for BCC?
4mm (unless high risk, then mohs)
What are high-risk features of BCC that should trigger a referral to Mohs?
>2cm in diameter on any site, >1cm diameter on face/neck/scalp, or >0.6cm diameter on high-risk areas (H-zone), poorly defined and aggressive histology (infiltrative, morpheaform, micronodular, and basosquamous, recurrent, at site of prior radiation/scar, perineural/perivascular invasion, and immunosuppression status (CLL, HIV or hematologic malignancy)
What margin is recommened for SCC?
4mm, for higher risk SCC –> 6mm or Mohs
What is the recommended margin for DFSP?
2-3 cm margins extending at least to the fascia
Gold standard is Mohs
What stage would a melanoma with in-transit metastases but without metastatic lymph nodes be categorized as?
N2, if the nodes are involved –> N3
What would a melanoma w/ in-transit metastases and nodal involvement be stages as (N-stage)?
N3
What areas are appropriate for second intention healing?
NEET mnemonic: Concvaities on the nose, eyes (medial canthus), ears (conchal bowl, etc), and temple
