Scalp Reconstruction Procedures

Scalp surgery is performed on an increasingly frequent basis. This article emphasizes scalp surgery and reconstruction as they pertain to dermatologic surgery and surgery performed by primary care physicians. Extensive surgical procedures of the scalp, such as those involving free flaps, procedures that involve removal of the calvaria, and other extensive procedures, are not covered.

Common procedures performed on the scalp range from those that are medically indicated to those performed for cosmetic reasons. These procedures include incisional and excisional biopsies, excisions of benign and malignant tumors, and scalp reduction surgery.

Incisional and excisional biopsies may be performed to aid in diagnosing benign and malignant lesions. Benign lesions include nevus sebaceous, epidermoid cysts, trichilemmal cysts, blue nevi, and melanocytic nevi. Malignant lesions include basal cell carcinoma, squamous cell carcinoma, squamous cell carcinoma in situ, Merkel cell carcinoma, and malignant melanoma. Wounds created from these procedures may be superficial, as in the case of an incisional shave biopsy, or extensive, as in the case of a large excisional biopsy in which the site cannot be closed primarily.

Excisions may be performed to diagnose and/or treat the conditions mentioned above. Wounds created from these procedures are generally full thickness and may extend to the calvaria.

Scalp reduction surgery was once performed to treat alopecia but is not commonly used today. Scalp surgery and reconstruction for cosmetic indications are not discussed here.

Reconstruction of the scalp after one of the above procedures may include any of the following techniques: granulation; side-to-side closure; the use of an advancement flap, rotation flap, or transposition flap; or the use of a split-thickness skin graft (STSG) or full-thickness skin graft (FTSG). ^{[1, 2]}

The selection of one or a combination of these methods depends on anatomic and patient-related factors. Anatomic considerations include the amount of local tissue laxity, the depth of the wound to be repaired, and the location of the wound. Patient-related factors include the patient's expectations, general state of physical and mental health, smoking status, and ability to care for the reconstructed wound.

In this article, each method of reconstruction is discussed in detail, with a review of its advantages and disadvantages, as well as ideal wound type and location, ideal patient type, and ideal technique for each method.

Anatomy and general considerations

For the purposes of this article, the scalp is defined as the skin and underlying tissue layers that extend to the periosteum. From the skin inward, these layers are, in order, the skin (epidermis), cutis (dermis and subcutaneous tissue and fat), aponeurosis, loose areolar tissue, and periosteum. These layers can be easily remembered with the mnemonic SCALP.

The image below demonstrates several layers of the scalp.

The image below depicts arterial blood supply to the scalp.

Anteriorly, the scalp borders the forehead. The line that divides the scalp and forehead is located at the junction of the frontalis muscle and the aponeurosis. This line can be visualized by asking the patient to raise his or her eyebrows. The forehead has an appearance of rugae due to the contraction of the underlying frontalis muscle. Superior to the forehead, the scalp has a smooth appearance. This smooth appearance can be easily observed in patients with alopecia. For patients with hair, the hair can be parted to visualize this line.

Laterally, the scalp borders the temples and auricles. The line that divides the scalp from the temple is located at the hairline. In patients with alopecia, the line is discerned by noting the transition from the increased amount of sebaceous glands and vellus hairs on the temple skin to the relative absence of those structures on the scalp skin. This line extends directly posteriorly from the temple, through the sideburn, to the superior border of the auricle. Correspondingly, the scalp occupies all the area above this line.

Posteriorly, the scalp extends to the posterior border of the auricles. From there, it covers the back of the head and is separated from the posterior part of the neck by a line that runs directly along the posterior part of the hairline.

The scalp is commonly divided into sections and is named based on the underlying skull anatomy. These sections are the left and right frontal, parietal, vertex, and occipital scalp.

The greatest amount of scalp mobility occurs in the parietal regions where the temporal fascia overlies the temporalis fascia. Scalp mobility is decreased at the superior temporal septum in the lateral frontal region because of the adherence of aponeurotic layers to the pericranium. These ligamentous areas may need to be released to gain tissue movement from this area. The occipital region may also contribute tissue for reconstruction, but, often, wide undermining is required.

The best replacement for scalp tissue is scalp tissue. No other site can approximate the same hair-bearing qualities of the scalp. Hair transplantation may be used to restore hair-bearing areas and is most effectively used as a secondary procedure to camouflage scars or reestablish hairlines.

Patients who have received radiation therapy to the scalp may have tissue that is fibrotic, resulting in decreased mobility and hardiness of flaps.

In hair-bearing areas of the scalp, incisions made parallel to the direction of hair growth may improve cosmesis because fewer follicles are disrupted. Extensive tension at wound closure may result in hair loss. Appropriate attention to obtaining closure with as little tension as possible is very important. Understanding the properties of stress relaxation and creep facilitate tension-free closures. Stress relaxation is the decrease in the amount of force needed to maintain a fixed amount of stress over time. A certain amount of relaxation occurs as tissue creeps. Stress relaxation allows large lesions in inelastic areas to be removed by serial excision. Creep is gain in skin surface area that results when a constant load is applied. An increase in length occurs as compressed tissue displaces interstitial fluid. Both stress relaxation and creep are time dependent properties of the skin.

The galeal aponeurosis also hinders flap movement. Scoring the galea in the direction of desired flap movement may result in additional tissue gain. The galea is incised at 1-cm intervals and checked for adequate mobility after each incision.

Flap methods

To create flaps, nearby redundant tissue is used to close a wound. However, the scalp usually does not have a significant amount of redundant or loose tissue to mobilize for wound closures. In general, flaps have limited applications in larger wounds on the scalp, although they may be used more often in smaller wounds.

Flaps discussed in this article are categorized as random pattern flaps. While the blood supply to these flaps comes from their pedicles, the blood supply to the pedicle comes from the random vascular supply in the epidermis, dermis, and subcutaneous fat. Random pattern flaps are distinguished from interpolated flaps, which derive their blood supply from a named vessel. ^[3]

In choosing between advancement, rotation, and transposition flaps, one must usually consider where nearby redundant tissue reservoirs and cosmetic subunit junctions are located. With knowledge of these areas, one may then choose the type of flap that most efficiently permits access to and use of the nearby redundant tissue with the placement of incision lines within or along cosmetic subunit junctions to leave the most cosmetically acceptable scar.

Russo elucidated a “1-2-3 rule” for helping to select the most effective means of reconstructing moderate-sized scalp defects. In a retrospective study of patients who had undergone excision of a cutaneous scalp tumor and whose defect could not be managed by simple direct suture, he found that if the defect’s edges were 1-2 cm apart, a single relaxation incision was required for reconstruction. Two incisions were needed for an edge distance of 2-3 cm, and three incisions were required when the edges were 3-4 cm apart. ^[4]

In a retrospective study of patients who underwent scalp reconstruction following oncologic ablation, Janus et al found higher complication rates in association with larger or deeper defects and in patients who had received preoperative radiation therapy or were immunosuppressed. The single-institution study, which had a mean follow-up period of 2.4 years, involved 139 patients, with reconstruction techniques in the report ranging from granulation to free tissue transfer. ^[5]

Granulation

Ideal wound type and location

In general, the more superficial a wound, the more appropriate granulation is as a method of reconstruction. The use of other methods of reconstruction requires the conversion of the partial-thickness wound into a full-thickness one. Superficial wounds heal more quickly and have a more aesthetically pleasing appearance than full-thickness wounds. Wounds that extend into only the dermis can heal in 2-3 weeks, whereas wounds that extend into the subcutaneous fat can require an additional 1-3 weeks to heal. Wounds that extend into deeper layers of the scalp, including the aponeurosis, loose areolar tissue, and periosteum, can require 6-8 weeks to heal. Wounds that contain bare calvaria can be healed by means of granulation, but they take the longest to heal.

Wounds in all locations of the scalp granulate in a relatively equivalent fashion; therefore, granulation is not contraindicated in any particular location.

Ideal patient

Good candidates for granulation include patients who desire the minimal amount of surgery, those capable of performing the required wound care, those who have wounds with potential residual tumor, and those with superficial defects.

Certain patients such as smokers, patients with diabetes, patients who have undergone prior radiation treatments, and patients with a history of poor wound healing may be better candidates for this method of reconstruction.

Side-to-side closure

Ideal wound type and location

The ideal wound for primary closure is any full-thickness scalp wound with edges that can be apposed without significant tension. Wounds closed side to side under excessive tension are prone to dehiscence or healing with a spread and depressed appearance. For this reason, adequate local tissue laxity is important for proper closure.

Wounds in all locations on the scalp are relatively equivalent in their suitability for primary closure; therefore, primary closure is not contraindicated in any particular area.

Ideal patient

The ideal patient for primary closure is one who does not mind undergoing an additional surgical procedure or a patient who has a wound that is easily closed primarily and who cannot perform the intensive wound care required for healing by granulation.

Advancement flap

Ideal wound type and location

The ideal type of wound for advancement flap repair is any full-thickness scalp wound that is not easily closed with primary closure. Primary closure is generally the preferred method of closure because it can be performed in the shortest time and requires the least amount of additional surgery.

The ideal wound location is any location where local tissue redundancy is adequate and incision lines may be hidden within or along cosmetic subunit junctions.

Ideal patient

The ideal patient for an advancement flap is a patient who does not mind undergoing an additional surgical procedure or one who cannot perform the intensive wound care required for healing by granulation.

Rotation flap

Ideal wound type and location

The ideal type of wound for rotation flap repair is any full-thickness scalp wound that is not easily closed with primary closure. Primary closure is generally the preferred method of closure because it can be performed in the shortest time and requires the least amount of additional surgery.

The ideal wound location is any location where local tissue redundancy is adequate and where incision lines may be hidden within or along cosmetic subunit junctions.

Ideal patient

The ideal patient for a rotation flap procedure is a patient who does not mind undergoing an additional surgical procedure or one who cannot perform the intensive wound care required for healing by granulation.

Transposition flap

Ideal wound type and location

The ideal type of wound for transposition flap repair is any full-thickness scalp wound that is not easily closed with primary closure. Primary closure is generally the preferred method of closure because it can be performed in the shortest time and requires the least amount of additional surgery. ^[6]

The ideal wound location is any location where local tissue redundancy is adequate and where incision lines may be hidden within or along cosmetic subunit junctions.

Ideal patient

The ideal patient for a transposition flap is a patient who does not mind undergoing an additional surgical procedure or one who cannot perform the intensive wound care required for healing by granulation.

Galeal hinge flap

The galeal hinge flap is used to resurface defects of the scalp extending to bone in cases in which the surgeon wishes to use full- or split-thickness skin grafting to close the wound in a single-stage procedure.

Split-thickness skin graft method

Ideal wound type and location

The ideal type of wound for STSG repair is any full-thickness scalp wound that is not easily closed with primary closure or flap repair. STSG repair is also a good option for the patient who is not a good candidate for the 4-6 weeks of wound care required for granulation. Lastly, STSG is a good option for a scalp wound that is too large or too devoid of a vascular bed for treatment with a FTSG. ^[7]

Ideal patient

The ideal patient for STSG repair is the patient who does not mind undergoing an additional surgical procedure or one who cannot perform the intensive wound care required for healing by granulation.

Full-thickness skin graft method

Ideal wound type and location

The ideal type of wound for FTSG repair is any full-thickness scalp wound that is not easily closed with primary closure or flap repair. FTSG repair is also a good option for the patient who is not a good candidate for the 4-6 weeks of wound care required for granulation.

Ideal patient

The ideal patient for FTSG repair is the patient who does not mind undergoing an additional surgical procedure or one who cannot perform the intensive wound care required for healing by granulation.

Granulation

Advantages and disadvantages

Advantages of granulation are as follows: (1) No additional surgery is required after the primary surgical procedure. (2) Granulation does not depend on a vascular pedicle (as flaps do) or vascular ingrowth (as grafts do) to survive. (3) Granulation can aid in the healing of large wounds and wounds that extend to the calvaria. (4) Recurrence of tumor can be easier to detect and manage in granulated wounds. (5) Granulation has the potential for an excellent cosmetic result.

Disadvantages of granulation include prolonged and intensive wound healing and the potential for an unsightly scar.

Regarding the first advantage listed above, if a full-thickness wound is to be reconstructed with primary closure, it must be reshaped into an ellipse if it is not already elliptical. This elliptical reshaping with its 3:1 length-to-width ratio facilitates primary closure without standing-cone tissue redundancies. In the case of flap repair, additional undermining, incisions, and freeing of local redundant tissue must be performed to cover the primary defect. In both of these situations, excision or another type of surgical manipulation of additional normal tissue is required. If a full-thickness wound is to be repaired by using an FTSG or STSG, another surgical wound must be created at the donor site, in addition to the suturing that is required to attach the graft at the recipient site. Therefore, granulation is suited for a patient who wishes to undergo the minimal amount of surgery possible.

Granulation is a predictable method of wound healing if the wound is cared for properly, and granulation is not as dependent on vascular pedicles or vascular ingrowths as flaps and grafts. Therefore, certain types of patients such as smokers, patients with diabetes, patients who have undergone prior radiation treatments, and patients with a history of poor wound healing may be better candidates for this method of reconstruction.

Granulation can be used to heal large wounds as long as wound care is meticulously performed and the patient and physician have patience. The surface area of granulated wounds becomes approximately 30% smaller than that of the original wound because of the contraction of wound myofibroblasts during the healing process. Even wounds that contain bare calvaria can heal by means of granulation if the wound is properly cared for and if the calvaria are not allowed to desiccate.

Tumor recurrence in wounds healed by means of granulation may be detected earlier and more easily than recurrence in wounds healed by other means, and it may be easier to manage and cure. If a scalp wound has or is likely to have residual tumor at the completion of an excisional procedure, granulation should be considered as a method of reconstruction. Residual tumor may spread throughout the reconstructed area because of the manipulation, undermining, or rearrangement of tissue that occurs in flap and graft repair.

If tumor spreads, it can do so superficially or along deep-tissue undermining planes. In these deep-tissue planes, the tumor faces little resistance to spread and can grow insidiously and extend until it is detected. At that point, it may be much larger and more extensive than the original tumor because the detection of tumor in deep-tissue planes can be difficult. With granulation and its lack of additional surgical manipulation, residual tumor is likely to remain in place, and it can be easily detected if it recurs. In these cases, further excision may be more limited than if a flap or graft had been used.

Granulation (healing by secondary intention) has the potential for an excellent cosmetic result. The final appearance of the healed wound often surpasses both the patient's and physician's expectations. A typical result is a slightly depressed, round or oval, hypopigmented scar. If the initial wound extended below the level of the hair follicles in the superficial subcutaneous fat, the scar is alopecic. Otherwise, hair regrows, and the appearance of the scar is not relevant because hair covers it. Another consideration is that granulating wounds contract. In fact, the final diameter of the healed scar may be as much as one third less than that of the original wound because of the natural contraction of wound myofibroblasts during granulation.

The main disadvantage of granulation is the prolonged healing time that averages 4-8 weeks, depending on the size and depth of the wound. Wound care must be fastidious in the postoperative period to optimize wound healing. Moist wound care is discussed in Technique, below. An additional disadvantage is that granulated wounds may be devoid of hair, depending on the depth of the wound. This disadvantage is more of a concern for wounds in hair-bearing areas.

Technique

The primary technique involved in granulation is proper moist wound care. Moist wound care consists of the application of a moist, nonallergenic, nonirritating emollient such as petroleum jelly; a nonstick layer such as petroleum jelly gauze or a petrolatum-impregnated dressing (eg, Adaptic); a protective and cushioning cotton gauze; and nonirritating tape such as paper tape or nonwoven tape (eg, Hypafix). This dressing is changed at least once a day and as often as needed to keep the wound moist. In some cases, a dressing may not be needed as long as a liberal layer of emollient ointment covers the wound at all times.

The use of antibiotic ointments should be avoided because granulating wounds almost never become infected and the potential for sensitization and allergic contact dermatitis is high. The wound should be cleansed once a day by gentle debriding and cleansing with soap and water or a dilute vinegar and water solution.

By following this method, healing should occur within 2-8 weeks, depending on the depth of the wound. If moist wound healing is not strictly performed, the wound may desiccate, and the granulation process may be slowed or arrested. Meticulous moist wound care may reverse the desiccation and permit the healing process to resume, or the dry eschar may be debrided, followed by meticulous moist wound care. Occasionally, a fresh large wound must be created to restart the granulation process.

Rarely, exuberant granulation tissue forms and actually extends beyond the original borders of the wound. This extension can arrest reepithelialization. In these circumstances, the excessive granulation tissue should be excised, and moist wound care should be continued until reepithelialization is complete. Other methods of removal may also be considered; these include curettage, chemical cauterization (with aluminum chloride or silver nitrate), and laser therapy (with a pulsed dye laser or carbon dioxide laser). Chronic erosive pustular dermatitis of the scalp may occur after surgery. The crusts and pustules at the periphery are accompanied by excessive granulation tissue. This condition responds best to the application of a fluorinated topical corticosteroid.

Two additional techniques, porcine xenograft–assisted granulation and purse-string suture–assisted granulation, may be used in a patient who cannot care for the wound but who is otherwise a good candidate for granulation (eg, an elderly patient who lives alone and a patient who is unable to see or reach his or her scalp).

In porcine xenograft–assisted granulation, the wound is first anesthetized, and a template of sterile gauze or perforated-film absorbent dressing (eg, Telfa) is placed on the wound. The template is cut to match the size of the wound. With this template, a commercially available porcine xenograft is cut to size and sewn to the wound with a narrow-caliber absorbable suture.

Because the xenograft may slough or liquefy after 2-3 weeks, the wound should be checked in 1-2 weeks. At this point, the xenograft can be removed, and the wound should be directly inspected for the presence of granulation tissue and for overall healing. If adequate granulation tissue is present and if healing is progressing well, the patient may continue with moist wound care. If inadequate granulation tissue is present or if healing has not progressed sufficiently, another porcine xenograft can be sewn to the wound, and the patient should be examined in another 1-2 weeks. This cycle is repeated as necessary. If porcine xenograft–assisted granulation is not an option because of the patient's preference, the patient's religious affiliation (eg, Watchtower Bible and Tract Society, Orthodox Judaism), or for other reasons, one of the other methods of reconstruction may be considered.

In purse-string–assisted granulation, a circumferential, large-caliber, absorbable purse-string suture is placed in the dermis in the wound. This suture is cinched and tied. The wound is closed completely, or more likely, its surface area is significantly reduced. The remaining wound may then be healed with a skin substitute, such as a porcine xenograft. A double purse-string closure has been described in which suture is first used in a subcuticular manner to create a classic purse-string closure. An additional epidermal running horizontal mattress suture is then placed to minimize the defect and provide extended wound strength. This technique can be useful in larger defects of the scalp. ^[8]

Side-to-side closure

Advantages and disadvantages

Side-to-side closure is often the preferred method to repair a scalp wound for a number of reasons. The healed wound has the potential to be cosmetically elegant, the repair is quick to perform, immediate wound healing occurs more quickly than with granulation, and wound care is minimal. The primary disadvantage is that additional surgery may be necessary to accomplish primary closure. Regarding the first advantage, if side-to-side closure is performed under minimal wound tension, the result can be a flat, thin, white linear scar. However, the linear scar can also be spread and depressed if the closure is performed under excessive tension.

Primary closure is relatively quick to perform, usually taking less time than the use of flaps and grafts.

Immediate external healing of the apposed wound edges occurs more quickly with side-to-side closure than with any other method of reconstruction. However, just as in any other full-thickness wound, most of the tensile strength of the wound is not achieved until a full month after the procedure, and many months of scar remodeling follows.

Because the external surface area of the wound is small and because it is the only area with apposed skin edges, it is requires minimal active wound care. However, the patient must not place excessive tension on the healing wound. The tensile strength of the wound is only 10-20% that of healthy skin at the time of suture removal on postoperative day 10. The wound attains maximum tensile strength of 70-80% that of normal skin only well after 1 month postoperatively. Placing excessive tension on the wound causes the scar to have a widened and depressed appearance at minimum; at worst, excessive tension causes wound dehiscence.

As mentioned in the Granulation discussion above, a full-thickness scalp wound must be shaped elliptically to close primarily without standing-cone tissue redundancies. Therefore, if the wound is not in this shape, additional tissue must be excised to convert the wound into an ellipse.

Technique

Layered closure under appropriate wound tension summarizes the technique of primary closure of the scalp. Wounds undergoing primary closure should be prepared first, and the wound edges should be square. The wound should extend to at least the subcutaneous fat because the residual dermis interferes with apposition of wound edges. Occasionally, the subcutaneous fat must also be removed because it may interfere with apposition of the wound edges. In this situation, the wound should extend to the loose areolar layer of tissue.

The wound should be roughly elliptical with a length-to-width ratio of approximately 3:1. This ratio results in wound end angles of roughly 30° and leaves the minimal amount of standing-cone tissue redundancy. If the wound is not in this shape, it should be reshaped to elliptical dimensions. Whenever possible, the elliptical wound should be oriented along relaxed skin-tension lines to minimize wound-closure tension. Undermining should also be completed to reduce wound-closure tension and to facilitate proper wound eversion. The loose areolar tissue layer is a good plane for undermining because it is relatively avascular, and its fibrous attachments offer little resistance to blunt or sharp undermining.

Hemostasis is obtained after the removal of enough dermis, subcutaneous fat, or both to (1) aid in wound edge apposition, (2) convert the wound to an elliptical shape to minimize standing-cone tissue redundancies, and (3) undermine wound edges to reduce wound tension and optimize wound eversion. A large-caliber absorbable monofilament or braided suture such as 3-0 polydioxanone or polyglactin 910 is recommended for the layer of buried sutures. These buried sutures should be placed as subcutaneous buried vertical mattresses to maximize wound eversion. A large-caliber monofilament or braided suture such as 4-0 nylon or silk is recommended for the layer of cutaneous sutures. Interrupted cutaneous sutures allow for more precise wound apposition and eversion. Cutaneous vertical mattress sutures should be used as needed for maximal wound support and eversion.

Wound care should consist of the application of a pressure dressing for 24 hours, followed by daily cleansings with gentle soap and water. Suture removal should occur around postoperative day 10, after which the patient should avoid subjecting the wound to excessive tension for at least 1 month to allow the wound to develop most of its tensile strength.

Advancement flap

Advantages and disadvantages

Advancement flaps are so named because the primary movement of mobilized nearby redundant tissue is advanced into the wound. Advancement flaps that may be considered for use on the scalp include the unilateral, bilateral, and island pedicle types. See the image below.

Flaps are usually considered in scalp reconstruction if primary closure is not an option because of an excessive wound size. Advancement flaps have advantages and disadvantages. One advantage is the immediate closure of a scalp wound, thus obviating the prolonged wound care associated with granulation. Advancement flaps also have the potential for excellent cosmesis, especially if the wound is in a hair-bearing area.

One disadvantage of flaps is the additional and occasionally extensive surgical manipulation of the wound, with the undermining of the defect and adjacent area and the need for additional incisions. This additional manipulation increases the risk of postoperative complications such as infection, hematoma, and dehiscence. Additionally, as previously mentioned, wound beds that are likely to contain residual tumor are not good candidates for flap repair because the tissue rearrangement may hide or spread the tumor, making its recurrence a more extensive problem.

Technique

Unilateral advancement flaps are generally used in smaller wounds. In this type of repair, an area of tissue that approximates the diameter of the wound is selected. Two parallel incisions are used to mobilize this area of tissue. Marking the sites with surgical ink is useful in planning these incisions.

The location and/or orientation of these incisions are determined with 2 primary factors in mind. First, the incisions should be located in the neighboring area that has the most redundant tissue to contribute to the closure of the wound. Second, the incisions should be oriented with respect to the cosmetic subunits so that the incision scars stay within or along cosmetic subunit junctions. The planning of incision lines within the 2 aforementioned parameters is not always possible, but these general rules should be followed whenever feasible. Incisions should be made to the same depth as the wound, and they should extend only as far as necessary to achieve the tissue movement needed to cover the wound.

The area of tissue to be mobilized is fed by a pedicle. In general, the ratio of the length of the pedicle to its width (which is the same as the diameter of the wound) should not exceed 3:1. The incidence of flap necrosis due to tenuous blood supply increases when this ratio is greater than 3:1. A flap length-to-width ratio of 3:1 is generally needed to gain the necessary tissue mobility to cover the wound. Wounds should be prepared for flap repair by ensuring that the wound edges are square, that the wound is of adequate depth and undermined sufficiently to allow easy movement of local tissue, and that hemostasis has been achieved.

The advancement of the flap into the wound creates wound edges of uneven wound length. The inner edge is shortened, and the outer edge is made relatively longer. This effect creates a standing-cone tissue redundancy that can be removed from both outer edges of the wound in the standard fashion.

Suturing of the flap occurs in a specific order. First, the donor site is repaired in a layered fashion. Appropriate-caliber absorbable and nonabsorbable suture materials are used for subcutaneous interrupted and cutaneous interrupted sutures, respectively. Next, the tension-bearing suture is placed. This suture holds the flap in place. Other subcutaneous and cutaneous sutures are placed as needed to appose the skin edges precisely. Examples of appropriate absorbable and nonabsorbable sutures include 3-0 to 5-0 polyglactin 910 and 4-0 to 6-0 nylon sutures.

If a unilateral advancement flap does not cover the wound adequately despite the use of a length-to-width ratio of 3:1 or greater, a bilateral advancement flap procedure may be performed. Bilateral advancement flaps are designed in a manner similar to that of unilateral advancement flaps. First, a unilateral advancement flap is designed as described above. A similar advancement flap is then designed on the opposite side of the wound to access any redundant tissue from that opposite area to aid in wound closure. In the design of bilateral advancement flaps, the location and orientation of each flap and their corresponding incisions should be determined as they are with unilateral advancement flaps. Local tissue redundancy should be used maximally, and incisional lines should be placed within or along cosmetic subunit junctions.

Island pedicle advancement flaps are a variation of a unilateral advancement flap. With an island pedicle flap, the tissue to be advanced into the wound is triangular. This piece of tissue is incised along its entire length to mobilize it. The flap is supplied by a subcutaneous pedicle, which is thinned and narrowed as needed to gain the necessary tissue movement to allow wound closure.

Island pedicle flaps are especially useful in the temporoparietal region, where the vascular anatomy of the scalp is unique. The superficial temporal artery branches into frontal and parietal branches above the zygomatic arch. The superficial temporal arteries do not lie in the subcutaneous tissue of the temporoparietal area. Laterally, they are localized in the temporoparietal fascia, which is continuous with the galea aponeurotica. The artery then enters the subcutaneous tissue at the level of the galea. This location allows elevation of flaps pedicled on the superficial temporal vessels. A Doppler probe may be used to locate the superficial temporal artery.

A triangular flap adjoining the defect is designed that includes the parietal branch of the superficial temporal artery. The flap is incised, and undermining is performed deep to the galea aponeurotica laterally and deep to the subcutaneous tissue medially. The flap is then elevated and transferred into the defect, followed by a standard V-Y closure. This method allows closure of various wounds with hair-bearing scalp and is another alternative in the armamentarium of the surgeon. ^[9]

Wound care consists of the application of a pressure dressing for 24 hours, followed by daily gentle cleansing with mild soap and water and the application of a dry bandage as needed. The tensile strength of the wound is low, and the wound requires a full month to regain 70% of the tensile strength of healthy skin. Therefore, the patient should be educated about the importance of not placing excessive tension on the wound, as an essential part of wound care. Failure to adhere to this caveat can result in scars that are spread and depressed, or even unexpected wound dehiscence. Sutures are removed on postoperative day 7.

A retrospective study by Shen et al of 18 patients found modified unilateral pedicled V-Y advancement flaps to be an effective means of repairing small to medium-sized scalp defects, with no major complications observed over an average 12-month follow-up and no neoplasms recurring at the original tumor site. ^[10]

Rotation flap

Advantages and disadvantages

Rotation flaps are so named because the primary type of movement of the mobilized nearby redundant tissue is rotation into the wound. Rotation flaps that may be considered for use on the scalp include the unilateral or single, bilateral, or multiple types. See the image below.

Advantages and disadvantages of rotation flaps are similar to those of advancement flaps. Advantages include the ability to immediately close a scalp wound, thus obviating the prolonged wound care associated with granulation. Rotation flap repair also has the potential for excellent cosmesis, especially if the wound is in a hair-bearing area. A retrospective study by Costa et al demonstrated the efficacy of rotation flaps in the reconstruction of complex soft tissue defects of the scalp. The study, which had a mean follow-up period of 13 months, involved 22 patients with large soft tissue scalp defects, including 19 who had undergone neoplasm resection; all patients were treated with rotation flaps. No intraoperative complications occurred, although three patients who had previously been treated with radiation therapy suffered distal flap necrosis. Twenty-one patients (95%) reported the surgery’s result to be cosmetically acceptable. ^[11]

Disadvantages of rotation flaps include the requirement for occasionally extensive surgical manipulation of the wound, with undermining of the defect and adjacent tissues and the need for additional incisions. This additional manipulation increases the risk of postoperative complications such as infection, hematoma, and dehiscence. Additionally, as previously mentioned, wound beds that are likely to contain residual tumor are not good candidates for flap repair because the tissue rearrangement may hide or spread the tumor, making its recurrence a more extensive problem.

Technique

Because neighboring redundant tissue is rotated into the wound around a point of rotation, the general shape of a rotation flap is an arc of a circle. The radius of this arc is equal to the diameter of the wound. Generally, the degrees of rotation and the length of the flap is equal to 3 times the number of degrees and 3 times the length of the wound, respectively. Another way to visualize this configuration is that, the circumference of a rotation flap is typically 3 times the diameter of the wound.

As a general guideline, the dimensions of a properly designed rotation flap approximate to sizing ratios mentioned above. For example, consider a hypothetical wound with a 2-cm diameter. An arc of rotation is designed on the basis of a larger circle that encompasses the wound. The radius of the larger circle is 2 cm, and its circumference is approximately 12.6 cm. The hypothetical wound occupies a rotational area of approximately 60° and 2.1 cm of the circumference of the larger circle. Therefore, the rotation flap is designed to occupy a rotational area of approximately 180° and 6.3 cm of the circumference of the larger circle.

Unilateral or single rotation flaps are generally used for smaller wounds, and they are designed as described above. The use of surgical marking ink may help in the flap design process. The location and/or orientation of the incisions are determined with 2 primary factors in mind. First, the incisions should be located in the neighboring area that has the most redundant tissue to contribute to the wound closure. Second, the incisions should be oriented with respect to cosmetic subunits so that incision scars stay within or along cosmetic subunit junctions. The planning of incision lines within the 2 aforementioned parameters is not always possible, but these general rules should be followed whenever feasible. Incisions should be made to the same depth as the wound, and they are designed to extend only as far as necessary to achieve the tissue movement needed to cover the wound.

The area of tissue to be mobilized is fed by a pedicle. In general, the ratio of the length of the pedicle to its width (which is the same as the diameter of the wound) should not exceed 3:1. The incidence of flap necrosis due to tenuous blood supply increases when this ratio is greater than 3:1. Wounds should be prepared for flap repair by ensuring that wound edges are square, that the wound is of adequate depth and undermined sufficiently to allow easy movement of local tissue, and that hemostasis has been achieved.

The rotation of the flap into the wound creates wound edges of uneven length. The inner edge is shortened, and the outer edge is made relatively longer. This effect creates a standing-cone tissue redundancy that can be removed from the outer edges of the wound in the standard fashion.

Suturing of the flap occurs in a specific order. First, the donor site is repaired in a layered fashion. Appropriate-caliber absorbable and nonabsorbable suture materials are used for subcutaneous interrupted and cutaneous interrupted sutures, respectively. Next, the tension-bearing suture is placed. This suture holds the flap in place. Other subcutaneous and cutaneous sutures are placed as needed to appose skin edges precisely. Examples of appropriate absorbable and nonabsorbable sutures include 4-0 to 5-0 polyglactin 910 and 5-0 to 6-0 nylon sutures.

If a unilateral or single rotation flap does not adequately cover the wound despite the use of a length-to-width ratio of 3:1 or greater, a bilateral or multiple rotation flap procedure may be performed. Bilateral rotation flaps are designed in a manner similar to that of unilateral rotation flaps. First, a unilateral rotation flap is designed as described above. A similar rotation flap is then designed on the opposite side of the wound to access any redundant tissue from that opposite area to aid in wound closure. In the design of bilateral rotation flaps, the location and orientation of each flap and their corresponding incisions should be determined as they are with unilateral rotation flaps. Local tissue redundancy should be used maximally, and incisional lines should be placed within or along cosmetic subunit junctions.

A multiple rotation flap procedure is performed by using the same concepts as those of a bilateral rotation flap except that, instead of only 2 rotation flaps, several are designed around the wound. As many rotation flaps may be designed as allowed by local tissue reservoirs. Generally, the minimum number of flaps should be used to minimize surgical manipulation and trauma to the local tissue. Each rotation flap has an associated standing-cone tissue redundancy similar to those of a unilateral or single rotation flap. Each of these standing-cone tissue redundancies should be removed in the standard fashion.

Wound care consists of the application of a pressure dressing for 24 hours, followed by daily gentle cleansing with mild soap and water and the application of a dry bandage as needed. The tensile strength of the wound is low, and the wound requires a full month to regain 70% of the tensile strength of healthy skin. Therefore, the patient should be educated about the importance of not placing excessive tension on the wound, as an essential part of wound care. Failure to adhere to this caveat can result in scars that are spread and depressed, or even unexpected wound dehiscence. Sutures are removed on postoperative day 7.

Transposition flap

Advantages and disadvantages

Transposition flaps are so named because the primary type of movement of the mobilized nearby redundant tissue is transposition into the wound over intervening tissue. The primary type of transposition flap that is used for scalp reconstruction is the rhombic transposition flap. Rhombic transposition flaps commonly used include the single or unilateral and bilateral types.

The advantages and disadvantages of transposition flaps are similar to those of advancement and rotation flaps. Advantages include the ability to immediately close a scalp wound, thus obviating the prolonged wound care that is associated with granulation. Transposition flap repair also has the potential for excellent cosmesis, especially if the wound is in a hair-bearing area.

Disadvantages of transposition flaps include the necessity of additional and occasionally extensive surgical manipulation of the wound such as the undermining of the defect and adjacent area and the need of additional incisions. This additional manipulation increases the risk of postoperative complications such as infection, hematoma, and dehiscence. Additionally, as previously mentioned, wound beds that are likely to contain residual tumor are not good candidates for flap repair because the tissue rearrangement may hide or spread the tumor, making its recurrence a more extensive problem.

Technique

Because the primary transposition flap used on the scalp is the rhombic transposition flap, the flap is usually some variation of a rhombus. In transposition flaps, neighboring redundant tissue is transposed into the wound over an intervening piece of tissue. To visualize the rhombic transposition flap, first imagine the wound as a rhombic shape. From one of the points of the rhombus, a flap of tissue is designed so that, once transposed, it fits into the wound.

Single or unilateral transposition flaps are generally used in smaller wounds. Surgical marking ink is useful in the flap design process. The location and/or orientation of incisions are designed with 2 primary factors in mind. First, the location of the incisions should be in the neighboring area that has the most redundant tissue to contribute to the wound closure. Second, the orientation of the incisions should be designed with respect to cosmetic subunits so that incision scars either stay within or along cosmetic subunit junctions. The planning of incision lines within the 2 aforementioned parameters is not always possible, but these general rules should be followed whenever feasible. Incisions should be made to the same depth as the wound, and they are designed to extend only as far as necessary to achieve the tissue movement needed to cover the wound.

The area of tissue to be mobilized is fed by a pedicle. In general, the length-to-width ratio of the pedicle is not an issue because the flap is usually broad based and not long. Flap necrosis is primarily the result of suturing a flap under excessive tension instead of using a flap length-to-width ratio of 3:1 or more. Wounds should be prepared for flap repair by ensuring that wound edges are square, that the wound is of adequate depth and undermined sufficiently to allow easy movement of local tissue, and that hemostasis has been achieved. Transposition of the flap into the wound creates wound edges of uneven wound length, which results in a standing-cone tissue redundancy that can be removed in the standard fashion.

Suturing of the flap occurs in a specific order. First, the donor site is repaired in a layered fashion. Appropriate-caliber absorbable and nonabsorbable suture materials are used for subcutaneous interrupted and cutaneous interrupted sutures, respectively. Next, the tension-bearing suture is placed. This suture holds the flap in place. Other subcutaneous and cutaneous sutures are placed as needed to appose skin edges precisely. Examples of appropriate absorbable and nonabsorbable sutures include 3-0 to 5-0 polyglactin 910 and 4-0 to 6-0 nylon sutures.

If a unilateral or single transposition flap does not adequately cover the wound, a bilateral transposition flap procedure may be performed. Bilateral transposition flaps are designed in a manner similar to that of unilateral or single transposition flaps. First, a unilateral transposition flap is designed as described above. A similar transposition flap is then designed on the opposite side of the wound to access any redundant tissue from that opposite area to aid in wound closure. In the design of bilateral transposition flaps, the location and orientation of each flap and their corresponding incisions should be determined as they are with unilateral transposition flaps. Local tissue redundancy should be used maximally, and incisional lines should be placed within or along cosmetic subunit junctions.

Island pedicle transposition flaps are another option, especially in the temporoparietal region where vascular anatomy of the scalp is unique. The superficial temporal artery branches into frontal and parietal branches above the zygomatic arch. The superficial temporal arteries do not lie in the subcutaneous tissue of the temporoparietal area. Laterally, they are localized in the temporoparietal fascia, which is continuous with the galea aponeurotica. The artery then enters the subcutaneous tissue at the level of the galea. This location allows elevation of flaps pedicled on the superficial temporal vessels. A Doppler probe may be used to locate the superficial temporal artery.

A triangular flap adjoining the defect is designed that includes the parietal branch of the superficial temporal artery. The flap is incised, and undermining is performed deep to the galea aponeurotica laterally and deep to the subcutaneous tissue medially. The flap is then elevated and transferred into the defect, followed by standard V-Y closure. This method allows closure of various wounds with hair-bearing scalp and is another alternative in the armamentarium of the surgeon. ^[12]

Wound care consists of the application of a pressure dressing for 24 hours, followed by daily gentle cleansing with mild soap and water and the application of a dry bandage as needed. The tensile strength of the wound is low, and the wound requires a full month to regain 70% of the tensile strength of healthy skin. Therefore, the patient should be educated about the importance of not placing excessive tension on the wound, as an essential part of wound care. Failure to adhere to this caveat can result in scars that are spread and depressed, or even unexpected wound dehiscence. Sutures are removed on postoperative day 7.

Galeal hinge flap

Advantages

Large scalp wounds that extend to bone may represent a challenge to repair. Often, the laxity required for primary or even cutaneous flap closure does not exist. Grafts are often not an option because of the lack of vascularity of exposed bone. A hinge flap of the adjacent galea aponeurotica in conjunction with a split- or full-thickness skin graft is an option in this case. The galeal hinge flap provides a vascular bed upon which a graft may be placed. ^[13]

Technique

Using a scalpel, the galea is incised, allowing the surgeon to dissect a partial-thickness plane of galea that is large enough to cover all of the exposed periosteal defect. The galeal flap is hinged over the exposed bone, transposing the flap into place. The galea is then sutured into place using buried interrupted absorbable sutures of 6-0 fast-absorbing gut. The remaining defect is then repaired using a split- or full-thickness skin graft.

Split-thickness skin graft method

Advantages and disadvantages

An STSG is defined as a graft of epidermis and partial-thickness dermis (see the image below). Generally, the use of STSGs is considered when granulation, primary closure, or a local flap procedure cannot be easily performed. These grafts contain no subcutaneous fat. STSGs are usually harvested with a manual or powered dermatome while the patient is under local, regional, or general anesthesia. These dermatomes usually have interchangeable guards that allow the harvesting of STSGs of different thicknesses. Typically, thicknesses in the range of 0.008-0.012 inches are used.

STSGs have some key differences, compared with FTSGs. Major advantages of STSGs versus FTSGs are that STSGs generally have a higher take rate, STSGs can cover a greater wound surface area because they can be meshed, the suturing of STSGs is relatively uncomplicated, and STSGs leave a donor site wound that does not require surgical closure. A major disadvantage of STSGs is that they take on a white, patchlike appearance, which can be a poor cosmetic match for an area such as the face or scalp. Another major disadvantage is that the donor site wound can be painful as it reepithelializes over 1-2 weeks.

STSGs have a higher take rate because they are thinner than FTSGs, and they have decreased metabolic requirements. FTSGs are grafts of epidermis and complete dermis with or without subcutaneous fat. Thus, FTSGs are thicker and have a higher metabolic requirement. STSGs can be meshed at different ratios to allow greater wound coverage. Meshing can be performed manually with a scalpel or scissors or with the aid of a skin-meshing device. STSGs can be sewn into place relatively easily because they do not require the meticulous edge-to-edge apposition that FTSGs do.

At the donor site of an STSG, a superficial wound referred to as an abrasion remains. This abrasion is left to heal by means of granulation, which generally leaves minimal scarring. No suturing is necessary at this donor site, in contrast to FTSG donor sites, which are, by definition, full-thickness sites that require suturing for closure. However, STSGs generally take on a white, thin, and well-demarcated appearance as they mature. Although this appearance can be an advantage in areas that contain similar tissue (eg, helix of the ear), it usually does not provide a good cosmetic match in the scalp or face.

Lastly, the abrasion wound at the STSG donor site requires 1-2 weeks to heal. This healing time can be a disadvantage because the wound requires care, especially during the first 72 hours when it generates a copious amount of serosanguineous exudate. In addition, these donor site wounds can be painful as they heal.

Technique

The technique for performing an STSG is divided into harvesting the STSG, attaching the STSG, and taking care of the STSG and donor site wounds.

Harvesting the STSG is usually accomplished with a manual or powered dermatome. Generally, a manual dermatome is used for small (ie, < 20-cm²) scalp wounds. For wounds larger than 20 cm², a powered dermatome may make the harvesting of larger STSGs easier.

First, the wound should be precisely measured. Alternatively, a template of the wound may be made by using a sterile suture foil pack, a piece of sterile gauze, or the sterile paper used to wrap surgical gloves. This measurement or template is transferred to the donor site and marked with surgical ink. The donor site should be an area that has a flat or slightly convex surface. This topography helps in the harvesting of the STSG. Typical donor sites are the biceps or triceps areas or the anterior part of the thigh.

Once the donor site is marked, it is locally anesthetized. The dermatome is then used to harvest an STSG of appropriate size. Because the STSG may shrink slightly after being harvested, the harvested STSG should be slightly (5-10%) larger than the wound.

After the graft is harvested, the primary consideration is to attach the STSG to the wound as soon as possible because the STSG exists in a state of relative anoxia until its attachment. The STSG is carefully transferred to the wound and unfurled. A running cutaneous small-caliber absorbable suture such as 7-0 polyglactin 910 or 6-0 fast-absorbing gut is used to attach the graft. Surgical staples may also be used for attachment, especially if the graft is fenestrated. Apposition of the STSG does not need to be as precise, as it is with FTSGs because any extra STSG simply necroses. The result is that STSGs appose themselves precisely; one does not need to expend additional time and effort in trying to exactly appose them with sutures or staples.

The donor site is covered with gauze moistened with 1% lidocaine and 1:100,000 epinephrine. This solution helps with both anesthesia and hemostasis of the donor site wound. If the STSG is of such a size that excessive movement and shearing may occur in the center, bolster sutures or staples should be placed as needed to properly secure the entire STSG.

Persistent oozing or bleeding from the wound can potentially lead to hematoma or seroma formation that may interfere with graft take. Therefore, if oozing or bleeding is a possibility, the graft can be manually fenestrated to allow blood and/or serum to drain. Lastly, a bolster dressing may be sewn over the STSG. A sample bolster dressing may consist of fluffed 4 X 4 gauze wrapped in a nonstick dressing (eg, Adaptic, Telfa) and secured in place with 4-0 silk tie-over sutures.

Wound care of the STSG depends on the presence of a tie-over bolster dressing. If a bolster is present, the periphery of the bolster should be gently cleaned with peroxide or soap and water to remove all crusts. In the absence of a bolster dressing, the STSG should be gently cleansed with soap and water daily. At all other times, the STSG should be protected from any type of friction or trauma.

Over time, the 3 stages of graft take occur: plasmatic imbibition, revascularization, and contraction. During plasmatic imbibition, which usually occurs on days 1-2, the STSG survives by means of the diffusion of oxygen and nutrients directly through the wound bed. The STSG may have an edematous and violaceous appearance at this time. During revascularization, on days 2-7, vessels start to grow from the wound edges into the apposing edges of the STSG (inosculation), and they grow directly into the body of the STSG. The STSG may become less edematous and pinker during this time. During contraction, on day 7 and afterward, edema gradually resolves, and the STSG more closely resembles normal skin.

Any trauma to the STSG during healing interferes with the ingrowth of blood vessels and collagen fibers. Severe trauma or friction results in the sloughing of the STSG. If a bolster is present, the STSG is not accessible, and wound care consists of simply avoiding all trauma. The bolster is removed in 1 week, at which point wound care continues as described above in the absence of a bolster. Because sutures are absorbable, no suture removal per se is needed.

The donor site is occluded with a polyurethane (eg, Tegaderm) or hydrocolloid (eg, DuoDerm) dressing. Occlusion shortens the healing time and decreases pain through a number of mechanisms. Occlusion keeps exudate and healing growth factors in direct apposition with the wound. It also keeps the wound moist and prevents the formation of a dry eschar, which slows healing by requiring reepithelializing keratinocytes to autolyze and tunnel under instead of simply gliding across a moist wound surface. Lastly, the occluded wound is less painful than a wound left open to air.

For full-thickness scalp wounds, STSGs by themselves usually result in a suboptimal cosmetic outcome and may not prove to be durable in patients who have received or who will receive radiation therapy. In addition, STSGs do not adequately restore lost volume. Local, regional, or free flap transfers have been described to repair such defects, but they can be associated with significant morbidity, particularly in an elderly patient who may not be able to tolerate general anesthesia or a lengthy reconstructive process.

Artificial dermis has been proposed as an alternative in such cases. ^[14] Integra is a bilaminate synthetic construct consisting of an outer silicone layer and an inner collagen-glycosaminoglycan matrix. The outer layer serves as an epidermal substitute and provides protection, whereas the inner layer, composed of bovine collagen, acts as a dermal regeneration template and promotes cellular growth. ^[15] Integra is fixed to the wound using skin staples and is covered with nonadherent dressings. The wound is then redressed weekly and monitored until sufficient neodermis is achieved, which may take up to 3 weeks or longer. The silicone layer is then removed, and an STSG may then be used to cover the defect.

Integra has also been used in cases in which bone has been exposed. The exposed bone is ground down to pinpoint bleeding and then Integra is placed on the wound. Once granulation occurs, the wound is covered with an STSG. ^[15]

A retrospective study by Maus et al indicated that the use of a dermal regeneration template and staged skin grafting is an effective means of postcancer scalp reconstruction. In the first stage of the procedure, performed after burr craniectomy, the template was applied to full- or partial-thickness extirpative scalp wounds in patients lacking periosteum. Skin grafting made up the second stage. Defects were 56 cm² on average. A 94.5% skin graft take was achieved in full-thickness wounds. A correlation was found between preoperative scalp radiotherapy and major complications, as well as delayed graft healing. Healing was more likely in association with negative pressure wound therapy than with a bolster. ^[16]

Patients with STSGs should be advised to expect copious exudate for the first 72 hours, with tapering thereafter. With this in mind, patients should change their dressings often during the first several days because the wound exudate will likely separate the dressing from the skin. When dressings are changed, the wound should be gently cleansed with mild soap and water. After the first 72 hours, wound exudate decreases considerably, and a single dressing can stay in place for 2-3 days before it needs to be changed. Because the dressings are watertight, patients may bathe as they normally do. Reepithelialization typically occurs within 2-3 weeks, after which the use of the dressings may be discontinued.

Full-thickness skin graft method

Advantages and disadvantages

An FTSG is defined as a graft of epidermis and full-thickness dermis. Generally, FTSGs are considered when granulation, primary closure, or local flap procedure cannot be easily performed. FTSGs are usually harvested with scalpels and other typical excisional surgical equipment while the patient is under local, regional, or general anesthesia.

FTSGs have some key differences compared with STSGs. Major advantages of FTSGs versus STSGs include the following: No additional specialized equipment (dermatomes), other than routine excisional surgical equipment, is required to harvest FTSGs, and FTSGs generally provide better cosmetic matching.

Disadvantages of FTSGs compared with STSGs include their inferior take rate, the more meticulous and precise suturing required to attach FTSGs to the wound, the inability to mesh FTSGs to cover more wound surface area, and the need to surgically repair FTSG donor site. For details regarding these advantages and disadvantages, refer to the Advantages and disadvantages discussion in the Split-Thickness Skin Graft Method discussion above.

Technique

The technique of performing an FTSG procedure is divided into harvesting the FTSG, attaching the FTSG, repairing the donor site, and taking care of the FTSG and donor site wounds.

Harvesting the FTSG begins by precisely measuring the wound or by making a precise template of the wound. A template of the wound is usually made by using a sterile suture foil pack, a piece of sterile gauze, or the sterile paper used to wrap surgical gloves. This measurement or template is transferred to the donor site and marked with surgical ink. The marked area should encompass the minimum width and length, as indicated by the measurements, and it should be in the shape of an ellipse to facilitate primary closure with a minimum of standing-cone tissue redundancies. Typical donor sites are the preauricular aspect of the cheek, postauricular sulcus, conchal bowl, supraclavicular or infraclavicular part of the chest, or any other area with redundant skin that is a good cosmetic match for the wound.

Once the donor site is marked, it is locally anesthetized, and the FTSG is excised. Because the FTSG may shrink slightly after being harvested, the harvested FTSG should be slightly (5-10%) larger than the wound.

After the graft is harvested, the primary consideration is to attach the FTSG to the wound because the FTSG exists in a state of relative anoxia until its attachment. However, the graft may be kept in sterile sodium chloride solution while the donor site is closed. The FTSG is carefully transferred to and positioned on the wound. A running cutaneous small-caliber absorbable suture such as 7-0 polyglactin or 6-0 fast-absorbing gut is used to attach the graft. Precise apposition of the FTSG is important. An improperly apposed FTSG may heal in a depressed or elevated position relative to the surrounding skin. This result is cosmetically unattractive and may require revision with a modality such as dermabrasion. If the FTSG is of such a size that excessive movement and shearing may occur in the center, bolster sutures should be placed to properly secure the entire FTSG.

Persistent oozing or bleeding of the wound can potentially lead to hematoma or seroma formation that can interfere with graft take. Therefore, if oozing or bleeding is a possibility, the graft can be manually fenestrated to allow blood and/or serum to drain. Lastly, a bolster dressing should be sewn over most FTSGs larger than a quarter. The bolster serves a couple functions: (1) to appose the FTSG to the wound to encourage graft take (see the discussion about the 3 stages of take later in this section) and (2) to protect the FTSG from inadvertent trauma. A sample bolster dressing may consist of fluffed 4 X 4 gauze wrapped in a nonstick dressing (eg, Adaptic, Telfa) and secured in place with 4-0 silk tie-over sutures.

The donor site is repaired next. The wound simply is closed primarily. Because the wound should is generally designed as an ellipse, no standing-cone tissue redundancies need to be removed. Primary closure should include a layer of subcutaneous absorbable sutures and a layer of cutaneous nonabsorbable sutures, both of appropriate caliber. An exception to this suturing involves the conchal bowl donor sites, which are not sutured but left to heal by granulation.

Wound care of the FTSG depends on the presence of a tie-over bolster dressing. If a bolster dressing is present, wound care should be performed by applying hydrogen peroxide or soap and water around the bolster to remove all crusts. In the absence of a bolster dressing, the FTSG should be gently cleansed with soap and water daily. At all other times, the FTSG should be protected from any type of friction or trauma.

Over time, the 3 stages of graft take occur: plasmatic imbibition, revascularization, and contraction. During plasmatic imbibition, which usually occurs on days 1-2, the FTSG survives by means of the diffusion of oxygen and nutrients directly through the wound bed. The FTSG may have an edematous and violaceous appearance at this time. During revascularization, on days 2-7, vessels start to grow from the wound edges into the apposing edges of the STSG (inosculation), and they grow directly into the body of the FTSG. The FTSG may become less edematous and pinker during this time. During contraction, on day 7 and afterward, edema gradually resolves, and the FTSG more closely resembles healthy skin.

Any trauma to the FTSG during healing interferes with the ingrowth of blood vessels and collagen fibers. Severe trauma or friction results in the sloughing of the FTSG. If a bolster is present, the FTSG is not accessible, and wound care simply consists of avoiding all trauma. The bolster is removed in 1 week, at which point wound care continues, as discussed above, in the absence of a bolster. Because the sutures are absorbable, no suture removal per se is needed. Wound care of the donor site is the same as that of any other primarily closed wound.