Disposable instrument setups (Figure 11-1B) may be the only option in practices that do not do regular surgeries and don’t have an autoclave. Note that disposable instruments are of lower quality than nondisposables.

The Elliptical Incision: Steps and Principles

The major steps involved in the elliptical excision involve the following:

1. Planning and designing the excision

2. Anesthesia

3. Preparing the room, the patient, and the equipment

4. Incision

5. Hemostasis

6. Undermining

7. Wound closure (repair).

Perform a check of vital signs and be aware of coexisting medical issues such as anticoagulation before starting any surgical procedure. Obtain informed consent in writing at the time of the procedure and perform a surgical time-out before starting (see Chapter 1, Preoperative Preparation).

Planning and Designing the Excision

Important factors to consider when planning an excision are listed in Box 11-1.

Avoiding Vital Structures

When planning an elliptical excision, it is crucial to plan how to best avoid damaging vital structures, including sensory organs, major nerves, arteries, bones, tendons, ligaments, cartilage, and internal organs. That is not to say that such damage can always be avoided because there are areas in which the risks are higher and the surgery still needs to be performed. Complications can include but are not limited to bleeding, paresthesias, paralysis, scarring, and loss of movement or expression. For example, a deep elliptical excision over the medial antecubital fossa may result in cutting the brachial artery. When possible, a shave technique can be used to perform a biopsy without the risk of cutting deep structures. Abnormal sensation at the immediate surgical site is expected and unavoidable due to damage to tiny sensory nerves. Damage to sensory nerves passing to other areas can cause more broad loss of sensation and paresthesias.

In planning the surgical excision, it is important to avoid cutting motor nerves. The temporal branch of the facial nerve is one example of a nerve at risk during facial surgery. For a superficial skin cancer in the temporal region, the clinician may choose to treat with a chemical agent or scoop shave rather than an ellipse. Referring for Mohs surgery is a good option because the temple is part of the H-zone and Mohs surgeons are very skilled surgeons.

Danger Zones

The three following areas are not the only areas at risk, but are worthy of special mention here because the motor nerves are superficial in these areas and damage to them can cause significant problems with form and function:

• Lateral forehead. The temporal branch of the facial nerve can be damaged by any surgery of the temple area. The nerve lies superficially within the fat layer; it can be difficult to see, and there is enough anatomic variation that its location can be unpredictable. The temporal branch emerges from the parotid gland, superiorly traveling in the subcutaneous fat to the frontalis muscle (Figure 11-2A). If the temporal branch of the facial nerve is cut, the patient will have permanent drooping of the eyebrow and not be able to wrinkle the forehead on that side (Figure 11-2B). If any surgery is to be performed in this area, it is important for this risk to be discussed with the patient.⁶ It also helps to check nerve function before administering anesthesia in this area because the anesthesia may cause a temporary facial nerve palsy.

• Lateral midface. The zygomatic branch of the facial nerve, the buccal branches, and the marginal mandibular branches emerge along the anterior portion of the parotid gland. The cervical branch emerges at the inferior aspect of the parotid gland (Figure 11-3).⁶ Any of these nerves can be damaged with resultant areas of facial paralysis, so care should be used if entering the subcutaneous tissues anterior, superior or inferior to the parotid gland and posterior to a line dropped inferiorly from the lateral canthus of the eye.

• Lateral neck. The spinal accessory nerve traverses under the sternocleidomastoid muscle on its way to the trapezius muscle (Figure 11-4). Within the posterior triangle between those muscles, at the level of the thyroid cartilage, it can be superficial. If this nerve is cut, the patient cannot raise the trapezius muscle. Fine hand–arm coordination can also be impaired.⁶

FIGURE 11-2 (A) The temporal branch of the facial nerve is superficial in the triangle formed by connecting the tragus to the lateral aspect of the eyebrow and the tragus to the most superior forehead crease. The temporal branch of the facial nerve is vulnerable to injury as it courses over the zygomatic arch within the zone. (B) This man is unable to raise his left eyebrow after receiving local anesthesia over the temporal branch of the facial nerve for the removal of a basal cell carcinoma. The effect on the nerve was temporary because the nerve was not cut.

(A: From Vidimos A, Ammirati C, Poblete-Lopez C. Dermatologic Surgery. London: Saunders; 2008; B: Copyright Richard P. Usatine, MD.)

FIGURE 11-3 Five branches of the facial nerve exit the parotid gland (temporal, zygomatic, buccal, marginal mandibular, and cervical) and are less protected posterior to the line dropped from the lateral canthus. The marginal mandibular branch is vulnerable to surgical injury as it crosses the inferior edge of the mandible.

(Adapted from Vidimos A, Ammirati C, Poblete-Lopez C. Dermatologic Surgery. London: Saunders; 2008.)

FIGURE 11-4 The spinal accessory nerve is vulnerable between the sternocleidomastoid and the trapezius at the level of the thyroid cartilage.

(From Vidimos A, Ammirati C, Poblete-Lopez C. Dermatologic Surgery. London: Saunders; 2008.)

Placement of the Incision Line

Major factors to be considered when determining the placement of the incision line are wrinkle lines and relaxed skin tension lines (RSTLs). The design of an ellipse on the face is usually done within wrinkle lines. If wrinkles are not apparent, asking the patient to smile, lift the eyebrows or tightly close the eyes can bring out lines of facial expression (Figure 11-5A). That is because these lines run perpendicular to the muscles of facial expression (Figure 11-5B).

FIGURE 11-5 (A) By raising the eyebrows and wrinkling the forehead, the skin tension lines are accentuated. These lines were used to draw the ellipse around a biopsy-proven basal cell carcinoma. (B) Wrinkles, termed skin tension lines (STLs), run perpendicular to the underlying muscle fibers. For example, the STLs of the forehead are horizontal because the frontalis muscle contracts vertically. (C) The drawing shows relaxed STLs of the face. Examples of drawn optimal fusiform excisions (blue) run parallel to relaxed STLs.

(A: Courtesy of Daniel L. Stulberg, MD; B: From Vidimos A, Ammirati C, Poblete-Lopez C. Dermatologic Surgery. London: Saunders; 2008; C: Redrawn from Hom DB, Odland RM. Prognosis for facial scarring. In Harahap M, ed. Surgical Techniques for Cutaneous Scar Revision. New York: Marcel Dekker; 2000:25–37.)

The RSTLs are the parallel skin lines that are seen when the skin is pinched together while the muscles are relaxed (Figure 11-5C). For example, when the skin is pinched together on the wrist, the RSTLs run horizontally from the lateral wrist to the medial wrist (Figure 11-6A). The RSTLs are used to plan the ellipse on the trunk, extremities, and on facial areas where wrinkle lines are not apparent (Figures 11-5 and 11-6).

FIGURE 11-6 (A) Pinching the skin to determine the direction of RSTLs. (B) RSTLs on the body.

(B: Redrawn from Fawkes JL, Cheney ML, Pollack SV. Illustrated Atlas of Cutaneous Surgery. Philadelphia: Lippincott-Gower; 1992.)

If neither the wrinkle lines nor the RSTLs are obvious, use the circular excision method of line placement. In this method, the lesion is excised in a circular fashion, and the surgical defect is undermined in all directions. The line of closure is chosen by looking at the direction in which the circle becomes elongated. The sides that are closer together or that can be pushed together are most easily sutured. Alternatively, the sides can be pulled together with skin hooks to determine the best direction of closure. Then remove triangles from two opposite ends to orient the ellipse along the appropriate closure line.

Surgical Margin

The ellipse is designed so that the lesion is cleared with a margin. When possible, knowing the type of lesion in advance can guide the amount of tissue to be removed. The surgical margin may be 3 to 5 mm for basal cell carcinomas, 3 to 6 mm for squamous cell carcinomas, and 1 to 2 cm for diagnosed melanomas (Table 11-1).^1,² When the suspicion for malignancy is low, a shave biopsy or an excision with smaller margins of 1 to 2 mm is usually adequate. For the initial excision of a suspected melanoma the margin should be 1 to 2 mm so as not to affect subsequent lymph node testing,⁷ and additional tissue will be excised later based on depth of invasion seen on pathology. One option for some suspected melanomas is to do a scoop shave excision with 2-mm margins since a full excision may be premature before histology is obtained (see Chapter 8, Choosing the Biopsy Type). It is important to balance taking enough tissue to reduce the need for repeat procedures due to positive margins while minimizing impact to form and function.⁸ In some cases it may be necessary to utilize Mohs surgery or take a smaller margin if the lesion is too close to vital structures.

TABLE 11-1 Surgical Margins by Lesion Type ^1,^2,^4,^5,¹¹^–¹⁴

Lesion Type	Surgical Margin
Uncertain	Consider shave or punch biopsy to delineate prior to elliptical excision or start with 1- to 2-mm margins to avoid unnecessary tissue removal.
Benign	Visible lesion removed.
BCC	3–5 mm
SCC	3–6 mm
Initial excision of possible melanoma	1–3 mm
Melanoma in situ	5 mm
Melanoma < 1 mm	10 mm (may need referral for lymph nodes 0.75 to 1 mm depending on ulceration, regression, or mitotic figures)
Melanoma > 1 mm	20 mm and lymph node evaluation

Ellipse Geometry

The ends of the ellipse should be approximately 30-degree angles so that potential dog ears (standing cones) are minimized (Figure 11-7). Standing cones consist of bulging skin at the ends of a sutured wound. Looser skin areas sometimes allow slightly larger angles at the end of the ellipse because the standing cones flatten slightly. Undermining the end of the ellipse also helps minimize these potential standing cones. A clinician should explain to patients before the surgery that the length of the incision needs to be about three times the diameter of the lesion. It is helpful to draw this for patients so they can see how large their incision will be.

FIGURE 11-7 (A) Most ellipses should be three times longer than they are wide with approximately a 3:1 ratio. (B) Ellipse drawn around a benign pilomatricoma on the upper arm using appropriate geometry.

(A: From Vidimos A, Ammirati C, Poblete-Lopez C. Dermatologic Surgery. London: Saunders; 2008.)

It is very helpful to mark the biopsy margins with a surgical marking pen (Figure 11-8). To orient the ellipse properly, determine the wrinkle line or relaxed skin tension line that will define the axis of the ellipse. The area to be cut may be prepped with alcohol first. A clean and nonsterile surgical marking pen is acceptable if you prep the skin again after marking the lesion. The usual ellipse is drawn so that the length of the ellipse is at least three times the width of the ellipse (Figures 11-7 and 11-8). Conditions in which a greater than 3 : 1 ratio may be desirable include tighter skin, skin over the joints, and curved surfaces.

FIGURE 11-8 Ellipse being drawn around a SCC. First the margins are drawn with a circle and then the ellipse is added.

(Copyright Richard P. Usatine, MD.)

Once the ellipse has been drawn with a surgical marking pen, it is advisable to pinch the skin again to make sure that the ellipse can be closed and that there will be minimal anatomic distortion. Use alcohol only sparingly on the site after the marking has been performed because alcohol will remove the marking. Prepare the skin with chlorhexidine or povidone-iodine after injecting the anesthesia and before starting the procedure.

Show patients the planned excision before you begin the surgery. You can show the patient and any family in attendance your surgical markings before you start. Keep a handheld mirror nearby for excisions on the face so that your patient knows what you plan to do. This is a helpful method to make sure you truly have informed consent.

Is Side-to-Side Closure Possible?

To decide whether side-to-side closure can be accomplished, pinch the skin to determine whether the skin within the area is loose enough. The clinician has to predict from pinching the skin whether the two sides of the ellipse can be brought together. Areas such as the cheek, trunk, and arms are areas where an elliptical excision can be easily accomplished. Areas that are most difficult are over the sternum and tibia.

Avoiding Distortion of Tissue

Elliptical excisions on the forehead, upper lip, and around the eye require careful planning because they can distort the eyebrow, lip, or eyelid. When possible it is better to orient an ellipse perpendicular to the eyelid or lip margin (Figure 11-5). For facial excisions, it is important to understand cosmetic units that relate to the organs of the face. Ask the patient to perform the following maneuvers: smile, show the teeth, raise the eyebrows, and purse the lips. It is best to keep the excision within one cosmetic unit rather than crossing between two units. When planning an excision, try to avoid creating functional problems with the eyes and mouth. Avoid pulling down eyelids and causing ectropion, pulling up eyebrows, cutting significant facial nerves, or distorting the look of the lip or nasal alae.

If there is doubt about whether the ellipse can be closed or if the potential exists for anatomic distortion, creation of a flap may be necessary (see Chapter 13, Flaps). In some instances the closure can be very tight. Wider undermining or thicker sutures may be required to accomplish the closure.

Anesthesia

The goal is to produce adequate anesthesia with minimal pain and anxiety for the patient. Local anesthesia is obtained using 1% lidocaine with epinephrine after the ellipse has been drawn. The area of anesthesia must cover the whole ellipse including the skin that will be undermined. Use of 1% lidocaine is preferable to 2% because a larger volume can be used more safely with 1% and this volume produces greater hemostasis by distention.

Epinephrine is valuable for all elliptical excisions and is used for virtually all patients in all surgical locations. For patients with normal circulation, it is safe to use epinephrine for local anesthesia in areas such as the tip of the nose, the fingers and toes, the ears, or the penis despite old dogma. In one study there was no evidence that buffered 0.5% lidocaine with epinephrine 1 : 200,000 causes ischemia or necrosis when injected into digits at the surgical site (not digital blocks).³ That was true despite a history of circulatory disorders, thrombosis, diabetes, smoking, anticoagulation, or significant preoperative hypertension.³ However, in patients with severe peripheral vascular disease or Raynaud’s phenomenon, one might discuss the risks and benefits with the patient.

Wait at least 10 minutes before making the incision so that the epinephrine can take effect, thus minimizing the bleeding. Maximal doses of 1% lidocaine (10 mg/mL) with epinephrine are calculated based on the formula of 7 mg/kg of body weight. For example, a 60-kg (132-pound) person could safely receive up to 42 mL at one time.

The amount of anesthesia needed depends on the location of the surgery and the thickness of subcutaneous tissue in the area. For example, the forehead and scalp have very little subcutaneous tissue because of the skull bones below, so a small amount of anesthesia will go far to distend tissue for hemostasis and numbness (Figure 11-9). However, excising an ellipse on the thigh or abdomen will require more anesthetic volume because the thicker subcutaneous tissues will soak up the volume faster. For an ellipse in the range of 1 × 3 cm to 2 × 6 cm, it is not unusual to need at least 20 to 30 mL of anesthesia. This should be safe for even the smallest adult. Plan ahead by drawing up at least one to two 10- to 12-mL syringes with anesthesia.

FIGURE 11-9 Injecting anesthesia before excising a BCC on the forehead. Note how the full ellipse with sufficient area to undermine can be anesthetized with a single injection using a 27-gauge, -inch needle on the forehead.

(Copyright Richard P. Usatine, MD.)

Add 8.4% bicarbonate in a 1 : 9 dilution to minimize pain and burning upon injection (see Chapter 3, Anesthesia). Pinch the skin at the area to be injected while injecting (based on the gate theory of pain). Start with a 30-gauge needle for the most sensitive areas and use a 27-gauge needle for less sensitive areas or when the initial anesthesia begins to work. Inject slowly because tissue distention hurts.

There are many ways to cover the needed area with anesthesia. Small ellipses can be anesthetized by a single injection distal to one end of the ellipse (Figure 11-9). For large excisions, one method that will minimize the number of painful injection sites begins with a single injection at one end of the ellipse that is far enough out to get the area to be undermined. The anesthesia is then delivered in a fanlike fashion until adequate volume is given (Figure 11-10

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