Shave excision describes the technique of sharp removal of epidermal or dermal lesions by horizontal slicing. Skin lesions can be removed by electrosurgical technique, conventional scissors, or scalpel shaving methods.
Shave excision usually extends to the level of the middle dermis, with the subcutaneous tissue left undisturbed. The shave biopsy is ideally suited for pedunculated lesions raised above the level of the surrounding skin. Skin lesions with a minimal dermal component, such as seborrheic keratoses or fibrous papules of the nose, are also excellent candidates for shave excision technique (Table 1). Pigmented nevi, subcutaneous lesions, and skin appendage lesions warrant the use of an alternative excision technique (Table 2).
|Acrochordon (skin tag)|
|Basal cell carcinoma (well-defined, small, low-risk area, primary)|
|Pigmented nevi (pathology specimen should be a full-thickness skin specimen down to the subcutaneous fat in the event the lesion is a melanoma)|
|Skin appendage lesions (syringomas, cylindromas, epidermoid cysts)|
|Subcutaneous lesions (may be missed by shave technique)|
It is essential when using the shave excision technique to go deep enough beneath the lesion to remove all of the cells of the growth to prevent recurrence. Generally, the deeper an excision extends into the dermis, the more scarring results. Fortunately, most excision sites heal with minimal postoperative scarring and pigmentary changes.
Electrosurgery refers to the cutting and coagulation of tissue using very high-frequency, low-voltage electrical currents. A blended current combines cutting and coagulation, and is useful in producing a bloodless operative field. Lesion excisions on the face are usually performed with only a cutting current to limit scarring at the wound base, which can be produced by the effects of thermal coagulation. A clear chemical hemostatic agent, such as 85 percent aluminum chloride, can provide the necessary hemostasis.
Inexperienced physicians often find it easiest to control the depth of excision by using a no. 15 blade held horizontal to the skin surface, which is then brought across the base of the lesion with long, unidirectional strokes.
Electrosurgical feathering (smoothing of the edges using fine brush strokes with the electrode) can then be performed to eliminate sharp wound edges and contour the wound to the surrounding skin. Feathering is generally performed only with an electrosurgical cutting current.
Dermal electrosurgical shave excision is a fast and inexpensive technique that does not require suture closure and is ideally suited for the busy physician because the setup and procedure can be performed rapidly. Electrosurgical generators on mobile carts can be moved into different examination rooms, facilitating performance of the procedure in the office setting.
Methods and Materials
The patient is seated (or lying) comfortably on the examination table with the skin lesion exposed.
Nonsterile Tray for the Procedure
Place the following items on a nonsterile drape covering a Mayo stand:
A 5- or 10-mL syringe filled with 2 percent lidocaine (Xylocaine), with or without epinephrine, and a 30-gauge needle
No. 15 blade
1 inch of 4 × 4 gauze
4 × 4 gauze soaked with povidone-iodine solution
A small disposable plastic (medicine) cup containing povidone-iodine solution
12 small cotton-tipped applicators
A small disposable plastic (medicine) cup containing Monsel's solution A small disposable plastic cup containing 85 percent aluminum chloride (if lesion is on the face)
Smoke evacuator with a special small particle (viral) filtration system
Small dermal loop electrodes
Place the patient in a comfortable seated or lying position on the examination table with the skin lesion exposed and illuminated. The lesion should be prepped with povidone-iodine solution and anesthetized with 2 percent lidocaine with epinephrine (5-mL syringe with a 30-gauge needle, or a 10-mL syringe if multiple lesions are to be removed). The lesion is raised with the administration of the anesthesia. The intradermal route of administration creates a blanch to the tissue that indicates the extent of anesthesia. Enough anesthesia should be administered to have a ring of anesthesia at least 1 cm from the lesion in all directions.
The area can be reprepped with povidone-iodine solution. The initial shave can be performed with a no. 15 blade that the physician holds horizontal to the skin surface and moves beneath the lesion (Figure 1). Experienced physicians may chose to remove the lesion with the electrosurgical loop (Figure 2). After removal, the specimen is immediately placed in formalin. Bleeding from the wound base is controlled by using a cotton swab to apply Monsel's solution (ferric subsulfate) or, on the face, clear 85 percent aluminum chloride.
Shave biopsy technique. The blade is held horizontal to the skin surface and brought below the lesion while the nondominant hand is used to stretch and stabilize the skin surrounding the lesion during the shave biopsy. Smooth, unidirectional cutting with the blade separates the lesion above from the deep (reticular) dermis below.ILLUSTRATIONS BY CHRISTY KRAMES
Electrosurgical loop technique. The lesion is grasped with forceps through the loop electrode. The electrode is activated going under the lesion, removing the growth.
The smoke evacuator is turned on, and the assistant holds the tubing next to the skin lesion site. The smoke evacuator has a special filter that prevents the dispersion of viral particles such as human immunodeficiency virus (HIV) and human papillomavirus (HPV). The smoke evacuator should be used the entire time that electro-surgery is being performed.
Electrosurgical feathering is performed with a small dermal loop electrode, using electrosurgical cutting and a setting of 1.5 to 2 (Figure 3). The handpiece is held in the operator's dominant hand, and short strokes (like the strokes of a fine painter) are made with the side of the electrode over the wound edges. The operator's fifth finger rests on the nearby tissues, stabilizing the operator's hand. The feathering removes additional cells from the wound base while smoothing the wound edges and blending the final wound color into the surrounding tissue.
Smoothing shave biopsy sites. (A) Dermal electro-surgical shave excisions can result in circular, crater-like defects that produce a step-off creating shadowing and leaving a noticeable scar. Some surgeons advocate the smoothing of shave biopsy skin edges to blend the healing wound into the surrounding tissues. Electrosurgical cutting using a low power setting can be effectively performed with a thin wire dermal loop. (B) The technique of electrosurgical “feathering” involves rapid, short brush strokes to smooth the edges and create a more cosmetically acceptable result.
The physician can use a finger to feel the shave excision site to ensure that no edges remain. If an edge can be felt, additional electrosurgical feathering can be performed to smooth the surface.
Monsel's solution can be reapplied if any bleeding persists. An antibiotic ointment, such as Mycitracin Plus, which includes a topical anesthetic, can be applied. A bandage can be placed, and the patient is given the postprocedure instruction form.
Histologic evaluation of the shave specimen may report a wide variety of benign growths such as angiofibroma, skin tag, or dermatofibroma. If the evaluation of a benign growth reveals that the specimen margin was positive (some cells remained at the excision edge), the lesion can probably be closely followed. Re-excision of the site is generally performed only if regrowth of the tumor is noted at a later date.
Shave excision specimens that reveal the margins to be positive for malignancy should prompt consideration for re-excision of the site. Some experts do not recommend automatic re-excision for basal cell carcinomas because of the superficial nature of these tumors. The electrosurgical shave excision technique also removes additional cells from the wound base, and this may prevent recurrence when the margin of the initial shave excision specimen margin is positive. Results from several studies have demonstrated that re-excision of basal cell carcinoma specimens with positive margins produces a high frequency of second specimens that have negative margins for malignancy. Basal cell carcinomas at low-risk sites, such as the cheek or neck, require close follow-up.
If the histologic analysis of a shave excision specimen reveals squamous cell carcinoma, full thickness re-excision of the site is recommended to completely eradicate the potentially metastatic lesion.
Ideally, a melanoma should never be shaved through because therapy and the long-term prognosis of the malignancy depend on the thickness of the lesion at histologic analysis. If a shaved excision specimen is reported to contain melanoma, consider referral to a subspecialist in skin cancer.
Occasionally, patients develop an excessive reaction known as a hypertrophic scar. This complication is more common at sites that have excessive tension on the scar, such as over the sternum, over the shoulder, or over flexion creases. Hypertrophic scars often shrink over time, and many experts advocate follow-up or treatment with single or multiple corticosteroid injections.
Shaving Lesions on the Face Produces Very Noticeable Scars. Scars on the face are usually noticeable because wound edges cast a shadow or because the final white scar is markedly different in color than the surrounding tissue. Electrosurgical feathering smooths sharp wound edges and gradually contours and grades the tissue from the wound base to the surrounding tissue. This contouring helps blend the final wound color into the surrounding tissue.
The Electrosurgical Shave Went Too Deep and Entered the Subcutaneous Fat. The shave excision technique is an intradermal excision technique. Family physicians rarely cut into the subcutaneous tissue. If the physician unintentionally cuts into the subcutaneous fat, the procedure should be changed to a full-thickness excision performed with a sterile surgical tray and a sterile field.
The Shave Technique Was Used to Remove a Pigmented Nevi. The shave excision technique should not be used for the removal of pigmented lesions that have any potential of being a melanoma. Melanomas rarely masquerade as a benign pigmented lesion, and a good rule to follow is to remove all pigmented lesions by full-thickness excision. The prognosis and treatment depend on the thickness of the lesion. A shave excision through a melanoma can prevent appropriate histologic identification.
Too Much Tissue Is Scooped Out When Excising the Lesion with the Loop Electrode. Physicians who are inexperienced in performing the electrosurgical shave excision technique often remove too much tissue with the first pass of the loop electrode. To limit the scooping effect, some physicians find it easier to control the depth of the initial excision by using a no. 15 blade. The electrosurgical loop is then used to feather the edges, removing additional cells from the wound base and refining the final wound appearance.
During the Procedure the Patient Receives an Unintentional Burn. The physician must always be observing the electrode tip whenever the electrode is activated. A burn can occur if the electrode is activated while being held close to another part of the patient's skin.
The Patient Complains of Pain During the Feathering of the Wound Edges. Adequate local anesthesia should be administered to prevent patient discomfort during the procedure. Electrosurgical feathering extends out from the wound base in all directions. Enough anesthetic should be infiltrated into the skin to produce a blanching that extends at least 1 cm from the lesion edge in all directions.
The mechanical techniques of dermal electrosurgical shave excision appear to be simple, but expertise in creating cosmetically superior wounds can take years to acquire. Electrosurgical feathering can be a highly difficult technique to master. Physicians in training should perform as many shave excision procedures as possible on nonfacial lesions. Once the fine hand motions have been mastered, removal of facial lesions can be attempted. It is recommended that physicians receive formal training in the use of electrosurgical currents, such as the courses in electrosurgery offered by the American Academy of Family Physicians.