Indications
Surgical intervention is the primary treatment modality for the majority of cutaneous malignancies. Mohs micrographic surgery (MMS) and traditional wide local excision are the most common surgical procedures used to treat cutaneous malignancies on the head and neck. Electrodessication and curettage may be used to treat low-risk basal cell carcinomas and in situ squamous cell carcinomas on non–hair-bearing areas.
Technique
Patient Preparation
Patient preparation is arguably the single most important step to ensure successful surgical outcomes. A thorough preoperative consultation should include the clinical diagnosis, indication for surgery, medical history, current medications, infectious history, response to anesthetics, anxiety level, and an assessment of the patient’s lifestyle and activity level. A preoperative questionnaire completed by the patient facilitates the preoperative consultation and helps identify potential problems to address prior to surgery.
When operating on face, it is best to have the patient in a supine or sitting position to incorporate the impact of gravity on resting skin tension lines into the planned excision and reconstruction. Single-use gentian violet marking pens are commonly used to mark the lesion. Alternatively, the broken end of a cotton-tip applicator dipped in gentian violet dye may also be used. After the lesion has been identified, a solid or dotted line may be drawn around the clinically apparent tumor ( Fig. 34.1 ).
Most cutaneous malignancies appear circular or ovoid, and one would expect to outline a circular pattern when marking the clinically apparent tumor. Subsequently, a second concentric circle that includes a margin of clinically normal appearing skin is drawn around the initial marking. When treating a clearly defined basal cell or squamous cell carcinoma, a margin of 3 to 5 mm of clinically normal appearing skin is typically adequate. If the excision is to be performed in an ellipse or fusiform fashion, the ellipse is then drawn with the marking pen along the relaxed skin tension lines ( Fig. 34.2 ). The apical angles at either end of the ellipse are ideally ≤30 degrees to avoid standing cone formation, and the length-to-width ratio should be ≥3:1.
Anesthesia and Antisepsis
Local anesthesia is typically used when performing cutaneous surgery. Lidocaine is the most commonly used local anesthetic and is the anesthetic of choice for pregnant women. The most commonly used lidocaine concentrations are 1% (10 mg/mL), 2% (20 mg/mL), and 0.1% tumescent (1 mg/mL). Additives to local anesthetics may include epinephrine (1:100,000) and sodium bicarbonate 8.5% (1 mL per 10 mL of 1% lidocaine).
Injecting in a ring distribution around the marked lesion is often adequate to achieve anesthesia. Additional anesthetization beyond the margins is recommended when anticipating undermining during closure. Regional nerve blocks of the supraorbital, infraorbital and mental nerves may also be utilized if necessary.
After adequate anesthesia has been achieved, it is necessary to prep the surgical site with an antiseptic. Common antiseptics include 70% isopropyl or ethanol, 2% to 4% chlorhexidine, and iodine/iodophors. The antiseptic should be applied in a circular fashion that spirals outward from the center. The surgical site is then draped using sterile surgical towels or fenestrated drapes.
Wide Local Excision Procedure
A No. 15 scalpel blade attached to a Bard Parker handle is commonly used when performing excisions. Traction may be placed by the surgeon’s nondominant hand or a surgical assistant. Using the anterior belly of the blade, the skin is incised at a 90-degree angle along one side of the ellipse with enough pressure to incise down to the subcutaneous fat. The incision is then repeated on the other side of the ellipse. Once both incisions have been completed, the incision through the base of the ellipse may be completed using the scalpel blade or straight or curved iris scissors. The specimen may then be elevated and placed in a specimen bottle. Cautery using an electrocautery or electrosurgical device may then be performed for hemostasis.
Undermining is subsequently performed using blunt dissection of the surrounding wound edge of the ellipse. The undermining plane is determined by the anatomic location of the surgical defect. A blunt-tipped dissecting scissors and skin hook may be used to facilitate the adequate undermining necessary to approximate the wound edges with minimal tension.
Once adequate undermining and hemostasis have been achieved, the wound is ready for closure. A layered closure consisting of a buried layer(s) of absorbable sutures and an epidermal layer of nonabsorbable sutures is commonly utilized to produce well approximated and everted wound edges. Suture removal for locations on the head and neck may be performed 3 to 7 days postoperatively.
Mohs Micrographic Surgery
MMS is a specialized method of skin cancer removal that involves microscopic evaluation of 100% of the excised margins (vs. <1% with vertical sectioning, i.e., “breadloafing” technique used for traditional elliptical excisions. During MMS, both the surgery and microscopic evaluation are performed by the same physician.
MMS has many advantages compared to traditional excision. The comprehensive margin analysis offers superior cure rates for most skin cancers. MMS is tissue sparing as smaller margins can be excised with confidence that the tumor is clear. MMS is also cost-effective and compares favorably relative to other treatment options.
Flaps in Reconstructive Plastic Surgery
Flaps are commonly utilized in reconstructive plastic surgery, particularly after MMS. Flaps may be indicated for surgical defects that will heal poorly by granulation, if a linear repair would compromise function, provide excessive tension, or distort a free margin. While flaps may be classified by blood supply, shape, and their eponymous name, they are best classified according to their primary motion.
Advancement Flap
The advancement flap moves tissue linearly and displaces a standing tissue cone (Burow triangle, dog ear) from the primary defect without redirecting the primary tension vector.
Rotation Flap
A rotation flap redirects the primary tension vector to a secondary arciform defect adjacent to the primary surgical defect. The rotational design aims to use a tissue reservoir distant from the primary defect. The length of the flap arc is typically much longer than the width of the primary defect. Due to pivotal restraint, the height of the flap must be taller than the height of the primary defect to decrease the secondary motion needed to close the defect ( Fig. 34.3 ).
Transposition Flaps
A transposition flap redirects the primary tension vector onto the donor site. The flap is elevated from an area of laxity, transferred over adjacent tissue, and transposed into the primary defect. Transposition flaps are prone to pin cushioning and wide undermining is often necessary to prevent this “trap-door” effect. The classic rhombic design is a parallelogram-shaped flap with two 60-degree angles and two 120-degree angles. The rhombic flap takes off from the defect at a 90-degree angle and a Burow triangle is typically removed at a pivot point. Several other eponym versions exist, such as the Limberg, Webster, and DuFourmental. In dermatologic surgery, the most commonly applied designs are the 30° Webster, the bilobed, and trilobed transposition flaps. Z-plasties are also a form of transposition flaps commonly used in scar revisions ( Fig. 34.4 ).
V-to-Y Advancement Flap (Formerly Island Pedicle Flap)
The V-to-Y advancement flap is a random-pattern flap that creates an island of epidermis and dermis with a vascular pedicle that is isolated to the subcutaneous tissue ( Fig. 34.5 ).
Interpolation (Two-Stage Transposition) Flaps
Staged flaps involve two or more stages, which are typically separated by 2 to 3 weeks. The mechanics are similar to single-stage transposition flaps. However, interpolation flaps retain a thick vascular pedicle, which can be either random pattern or axial. The increased blood flow in interpolation flaps allows for a longer flap-to-width ratio and enables coverage of very large defects. Interpolation flaps are commonly used for large defects on the nose, large helical rim defects, and large lip defects ( Fig. 34.6 ).
The paramedian forehead flap is an axial flap supplied by the supratrochlear artery and can have a maximum length from the orbital rim to the frontal hairline. The pedicle width is between 1.0 and 1.5 cm and is typically positioned on the opposite side of the primary portion of the nasal defect ( Fig. 34.7 ). The pedicle arises at the medial eyebrow and is oriented in vertical fashion. The body of the flap is elevated in a cephalad to caudad manner in a plane just above the periosteum. The tip of the flap is thinned extensively before suturing it onto the nasal tip. The pedicle is subsequently divided and inset after 3 weeks. The flap can also be thinned in a separate session prior to division to improve the skin thickness ( Fig. 34.9 ).
The melolabial/nasolabial interpolation flap is a random pattern flap perfused by small perforators of the angular artery and is primarily used for defects involving the nasal ala. While its design is similar to a single-stage melolabial transposition flap, it retains a thick vascular pedicle, which is divided and inset after 3 weeks and does not blunt the alar crease.
The retroauricular flap is a rectangular random pattern flap that is raised in the subcutaneous plane starting from the retroauricular sulcus and extending posteriorly to the hairline. The flap tip is thinned and sutured onto the helix, and the pedicle is divided after 3 weeks. The retroauricular flap is useful for large defects involving the helical rim with or without loss of cartilage.
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
