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Management of scalp defects
MANAGEMENT OF FACIAL CUTANEOUS DEFECTS, PART I
0030-6665/01 $16.00 + .OO
MANAGEMENT OF SCALP DEFECTS John F. Hoffmann, MD
ANATOMY The scalp is a multilayered region of the head with a robust blood supply. The layers of the scalp, from outermost to deep, often are described by the mnemonic S-C-A-L-P: S for the skin; C for the subcutaneous tissues; A for the aponeurosis or galea; L for the loose connective tissue; I' for the pericranium. These layers are consistent over the entire scalp except over the temporalis muscle where one encounters also the temporoparietal fascia and the temporalis muscle and fascia between the galea and pericranium. The subcutaneous layer contains the major blood vessels and the hair follicles and related integumentary structures. The scalp relatively is inelastic when compared with other facial tissues. This stiffness is largely because of the well developed and tough galea aponeurosis that forms a fibrous connection between the frontalis muscle anteriorly and the occipitalis muscle posteriorly. Most scalp flaps, as a result, resist transposition and extension and often need to be larger than flaps designed elsewhere in the face. The beneficial aspect of the indistensible nature of the scalp is that the vasculature of flaps is protected against distortion and attenuation from stretching or tension. In some instances, it may be helpful to lightly score the aponeurosis on the undersurface of the flap to allow some additional length or width of a scalp flap. Obviously, one must be careful to not damage the vasculature running just superficial to the galea when scoring the aponeurosis. From the Department of Otolaryngology-Head and Neck Surgery, University of Utah, Salt Lake City, Utah
OTOLARYNGOLOGIC CLINICS OF NORTH AMERICA VOLUME 34 NUMBER 3 JUNE 2001
571
572
HOFFMA"
The scalp has a robust and extensively interconnected blood supply (Fig. 1). The scalp is fed by five consistent arteries on each side: (from anterior to posterior) supratrochlear, supraorbital, superficial temporal, posterior auricular, occipital. The superficial temporal also has distinct anterior and posterior branches. These vessels widely and extensively interconnect with some anastomoses extending across the midline. In adults, these vessels permit the formation of long axial flaps that are quite resistant to distal necr~sis.~ In children, however, long axial scalp flaps are at some risk of necrosis and initial delay of the flap may be advisable.6It is thought that pediatric flaps are at greater risk because the galea is less well developed and thus the vessels within the flap are less protected from stretching and attenuation. When designing flaps on the scalp, the surgeon should keep in mind the location of the major axial blood supply and incorporate it within the base of the flap if at all possible. At times, Doppler mapping of the pedicles can be quite helpful especially for long, narrow axial flaps (e.g., Juri flaps). Branches of the first branch of the trigeminal nerve provide the sensory innervation of the scalp anteriorly. The occipital branches of the cervical
Figure 1. Vascular anatomy of the scalp. The major arteries of the scalp are shown along with the rich anastomoses between them. These anastomoses extend across the midline in many locations.
MANAGEMENT OF SCALP DEFECTS
573
nerves posteriorly supply the posterior scalp. Local anesthesia of the scalp easily is obtained with circumferential or crown blocks.
APPROACHES TO RECONSTRUCTION Healing by Secondary Intention
Although often not considered by the reconstructive surgeon, allowing wounds to heal by secondary intention often can be effective in the scalp. The principal drawback of course is that wounds that heal in this manner will not contain hair. Thus, one should consider this option only for those areas that are hairless or are in bald regions. In addition, these scars may be atrophic and have prominent telangiectasis that may be unsightly2 Occasionally, the end result may provide a superior esthetic result when compared with the scars of flap repair. The main disadvantage is the time and attention to wound care that will be required. If the wound is devoid of viable pericranium, then it may be beneficial to create small burr holes through the outer table of cortex down to the diploe that encourages the formation of a bed of granulation tissue. Wound care and protection against desiccation is of primary importance when allowing a wound to heal by secondary intention.
Skin Grafts
In general, skin grafts should be avoided in scalp repair as they give a poor cosmetic result and are prone to bleeding, ulceration and pain. Skin grafts require a viable substrate under them such as intact pericranium or fascia because they typically will not survive over exposed bone alone. If one wishes to employ a skin graft over bone, then one should consider methods to encourage the formation of a bed of granulation tissue first. The skin graft then can be applied after a healthy foundation of granulation has been established. In most cases, a skin graft should be considered as a means of temporary coverage of the scalp while preparing the scalp for a definitive repair with a flap of some sort. If long-term tissue expansion is needed to obtain a flap of adequate area, then it may be beneficial to cover the defect with a temporary skin graft while expansion progresses. Once the flap is ready for elevation and transfer, the graft can be removed and replaced with the prepared flap. Alternatively, one might consider staged, sequential excision of the graft with reconstruction with rotation flaps. A skin graft also may be needed with microsurgical muscle (e.g., rectus), or free flaps, which provide a vascularized cover for the bone but lack skin coverage.
574
HOFFMANN
Hair Replacement Techniques for hair replacement in male pattern baldness are beyond the scope of the article, but some of these can be applicable to traumatic or oncologic scalp defects. In general, scarred tissue does not accept hair transplants well, but in selected patients, they can be successful. Large pedicled flaps can be employed for large areas of alopecia especially along the anterior hairline.'4,'6Micrograft hair transplants harvested from the occipital scalp can be employed successfully in the camouflage of areas of scar or skin grafts that have been given adequate intervals to heal (Fig. Z).'
Figure 2. A, Traumatic partial-thickness avulsion of the occipital scalp. €3, Loss of hair in scar after allowing traumatized area to heal for a few months. C, Appearance after two sessions of micro hair transplants into scarred scalp.
MANAGEMENT OF SCALP DEFECTS
575
Primary Closure Because the scalp is so inelastic, only small defects of a few centimeters or less can usually be closed primarily. Very wide underminingessentially ear to ear and from anterior to posterior hairlines-in a subgaleal plane usually will be required and will be beneficial in reducing standing cone deformities in the thick scalp. Intraoperative tissue expansion and skin closure devices have been advocated as aids to the primary repair of scalp defects.’, l3 Increased wound tension and related alopecia may be a concern with these techniques. Galeal incisions (Fig. 3 ) may be employed to allow enhanced stretch of the wound edges during closure. Typically these are placed parallel to the incision line allowing reduced wound closing tension. Care should be taken to avoid damaging major blood vessels while incising the galea. Occasionally, it may be helpful to transilluminate the flap while planning these galeal incisions, because one may be better able to visualize the course and location of the larger vessels. Tissue Expansion Two distinct types of tissue expansion have been described in the scalp: long-term tissue expansion and intraoperative sustained tissue expansion. These techniques are physiologically and histologically distinct. Long-term, progressive tissue expansion is a widely accepted technique in scalp reconstruction that involves the surgical placement of a Silastic balloon under the galea.7,l2 The balloon gradually is inflated with saline over a period of six to eight weeks until the desired volume is obtained.
Figure 3. Galeal incisions made on undersurface of scalp flap to facilitate closure. These incisions should be made with care to avoid damage to the vascular structures.
576
HOFFMANN
Figure 4. A, Traumatic wound of the forehead and scalp. B and C, Scalp defect seen with tissue expanders in place near completion of expansion. Note the extent of expansion of the surrounding scalp needed. Two expanders are in place superior and posterior to the defect. Illustration continued on opposite page
MANAGEMENT OF SCALP DEFECTS
577
Long-term expansion results in physiologic and morphologic changes in the scalp while increasing the surface area of the f l a ~ . ~A, dense '~ fibrous capsule forms around the expander and blood supply to the scalp is enhanced. This enhanced blood supply in the expanded tissue particularly may be beneficial when developing scalp flaps that have a compromised vascularity (e.g., postirradiation). The overlying epidermis typically does not thin and mitotic activity within the expanded tissue increases. The density of the overlying hairs decreases because the surface area increases while the number of hair follicles remains the same. Alopecia usually does not occur with careful and judicious expansion although there may be some dryness or hyperpigmentation of the skin. The selection of the appropriate size and shape of the expander to be used requires clinical experience and judgment. A rule of thumbI7 for expansion of scalp flaps is to fill the expander to 2 to 2.5 times the size of the defect to be reconstructed (i.e., expand the flap to 16 cm for an 8 cm defect). Crescent or round expanders are employed frequently for scalp flaps. It may be necessary to employ two separate expanders, one on each side of the defect, to obtain the volume needed to get adequate flap expansion. Typically the expander is placed adjacent to the defect and then gradually inflated beginning two weeks after implantation over a period of six to eight weeks. Once the desired amount of expansion is reached, the expander is removed and the flaps are raised and inset (Fig. 4). The scalp is an ideal place for
Figure 4 (Continued). D,Postoperative result after expanded scalp flap repair and forearm free flap to forehead.
578
HOFFMANN
long-term tissue expansion, because the tissue is thick and vascular, thus resistant to exposure or extrusion of the expander-the most common complication. Furthermore, the solid calvarium provides an ideal base for the expander. Intraoperative tissue expansion (ITE)in contrast does not induce physiologic or histologic changes in the kin.'^,^^ ITE is performed in one setting by placing a balloon (or larger Foley catheter) under the galea and inflating it for three cycles of inflation and deflation immediately before flap elevation (Fig. 5). Although not fully understood or accepted, it has been theorized that ITE takes advantage of mechanical creep in the tissues. Creep is a mechanical process in that the interstitial fluid and ground substance is displaced in the expanded tissue and there is fragmentation of elastin and collagen fiber realignment." Some investigators have claimed that ITE is merely a way to enhance undermining and tissue redraping." In any case, ITE may facilitate the raising of scalp flaps but one should only expect an additional 1 to 1.5cm of flap length with this technique and one should be very aware of wound tension with closure of flaps with this te~hnique.'~
Figure 5. A, Mohs defect of the parietal scalp. 19,lntraoperative sustained tissue expansion of rotation flap with large volume foley catheter. C,Flap rotated into place. D, Postoperative result of healed reconstruction.
MANAGEMENT OF SCALP DEFECTS
579
Local Flaps Local rotational or advancement flaps are the mainstays of scalp reconstruction. The flaps follow the same general guidelines as elsewhere in the face except that they typically need to be longer and proportionally larger than other facial flaps because the scalp is so inelastic.' For example, for a defect of 3 cm in width, a rotational flap of 15 to 18 cm may be needed (Fig. 6). The most common design is a broad rotation flap. It is
Figure 6. A, Traumatic avulsion of the parietal scalp. B, Large rotation flap used to close defect. Note that almost the entire scalp was undermined to allow flap rotation and closure. C, Postoperative result with maintenance of hair growth and hairline.
580
HOFFMANN
ideal to design the flap so that a major vascular pedicle will enter the base of the flap. One should also consider the location of the hairline and design the flap so that an incision can be hidden there. In some instances, multiple flaps will be needed to provide adequate tissue (Fig. 7). Regardless of the flap design, one should try to minimize trauma to the hair follicles by making all incisions parallel to them and to utilize forceps or electrocautery judiciously.Most often flaps are elevated in a subgaleal plane with
Figure 7. A, Large Mohs full-thickness defect of the vertex on a bald scalp. B, Two large rotation (pinwheel) flaps designed. Very wide undermining of entire scalp is required for flap rotation and scalp closure. C,Postoperative result.
MANAGEMENT OF SCALP DEFECTS
581
very wide undermining as in primary closure. Galeal incisions can be employed as needed to facilitate wound closure. The galeal sutures that may reduce the pull on the hair follicles and lessen any alopecia typically take up the wound tension. In those cases where an extremely large defect is anticipated, long-term tissue can be successfully employed to provide large surface area flaps with enhanced blood supply. Free Flaps In recent years, microvascular free flaps increasingly have been employed for larger scalp defect^.^,'^ These flaps can provide large areas of vascularized tissue for scalp defects (Fig. 8). Although these flaps are reliable and highly successful, they rarely provide a good esthetic result because of poor tissue match and lack of hair growth. They may be, however, the only option for those cases where a large segment of calvarial bone is exposed and there are no other local or regional flap options. In order to improve the esthetic result, hair transplants and tattooing can be added to free flaps at a later date as desired.
Figure 8. Latissimusdorsi free flap employed for a massive basal cell carcinoma of the scalp and face. An auricular bone-anchored prosthesis and hair transplants are planned.
582
HOFFMANN
References 1. Ahuja RB: Geometric consideration in the design of rotational flaps in the scalp and forehead region. Plast Reconstr Surg 81:900,1988 2. Fosko SW, Branham GH: Reconstruction issues after Mohs surgery. Fac Plast Surg Clin North Am 6:379,1998 3. Furnas H, Lineaweaver WC, Alpert BS, Buncke HJ:Scalp reconstruction by microvascular free tissue transfer. Ann Plast Surg 24:431,1990 4. Johnson TM, Lowe L: Histology and physiology of tissue expansion. J Dermatol Surg Oncol19:1074,1993 5. JuriJ, Juri C: Aesthetic aspects of reconstructive scalp surgery. Clin Plast Surg 8:243,1981 6. Jurkiewicz MJ: Scalp reconstruction with multiple flaps. In Brent B (ed): The Artistry of ReconstructiveSurgery. St Louis, CV Mosby, 1987, p 449 7. Konior RJ, Kridel RWH: Tissue expansion in scalp surgery. Fac Plast Surg Clin North Am 2:203,1994 8. Limmer BL, Buchwach KA: Hair transplantation using follicular unit micrografting. Fac Plast Surg Clin North Am 7523,1999 9. Ling EH, Wang T D Local flaps in forehead and temporal reconstruction. Fac Plast Surg Clin North Am 4:469,1996 10. Lutz BS, Wei FC, Chen HC, et al: Reconstruction of scalp defects with free flaps in 30 cases. Br J Plast Surg 51:186,1998 11. Mackay DR, Saggers GC, Kotval W, et a1 Stretching skin: Undermining is more important than intraoperative expansion. Plast Reconstr Surg 86:722,1990 12. Manders EK, Graham WP, Scheiden MJ, et al: Skin expansion to eliminate large scalp defects. Ann Plast Surg 12:305,1984 13. Mandv SH: Intraoperative expander-assisted scalp reduction. J Dermatol Surp, Oncol 19:lllO-1116 14. Minor LB, Panje WR Malignant neoplasms of the scalp. Otolaryngol Clin North Am 26:279,1993 15. Pasyk KA, Argenta LC, Austed ED: Histopathology of human expanded tissue. Clin Plast Surg 14:435,1987 16. Rousso DE: The use of scalp flaps for frontal alopecia. Fac Plast Surg Clin North Am 2:183, 1994 17. Sasaki GH: Tissue expanders and general guidelines for tissue expansion technique. In Tissue Expansion in Reconstructive and Aesthetic Surgery. St. Louis, Mosby, 1998, pp 11-14 18. Sasaki GH: Intraoperative sustained limited expansion as an immediate reconstructive technique. Clin Plast Surg 14:563,1987 19. Shapiro AL, Hochman M, Thomas JR, Branham G: Effects of intraoperative tissue expansion and skin flaps on wound closing tension. Arch Otolaryngol Head Neck Surg 122:1107,1996 20. Siegert R, Weerda H, Hoffman S, et al: Clinical and experimental evaluation of intermittent intraoperative tissue expansion. Plast Reconstr Surg 92:248,1993 v
Address reprint requests to John F. Hoffmann, MD Department of Otolaryngology-Head and Neck Surgery University of Utah Suite 3C120 50 North Medical Drive Salt Lake City, UT 84132
0030-6665/01 $16.00 + .OO
MANAGEMENT OF SCALP DEFECTS John F. Hoffmann, MD
ANATOMY The scalp is a multilayered region of the head with a robust blood supply. The layers of the scalp, from outermost to deep, often are described by the mnemonic S-C-A-L-P: S for the skin; C for the subcutaneous tissues; A for the aponeurosis or galea; L for the loose connective tissue; I' for the pericranium. These layers are consistent over the entire scalp except over the temporalis muscle where one encounters also the temporoparietal fascia and the temporalis muscle and fascia between the galea and pericranium. The subcutaneous layer contains the major blood vessels and the hair follicles and related integumentary structures. The scalp relatively is inelastic when compared with other facial tissues. This stiffness is largely because of the well developed and tough galea aponeurosis that forms a fibrous connection between the frontalis muscle anteriorly and the occipitalis muscle posteriorly. Most scalp flaps, as a result, resist transposition and extension and often need to be larger than flaps designed elsewhere in the face. The beneficial aspect of the indistensible nature of the scalp is that the vasculature of flaps is protected against distortion and attenuation from stretching or tension. In some instances, it may be helpful to lightly score the aponeurosis on the undersurface of the flap to allow some additional length or width of a scalp flap. Obviously, one must be careful to not damage the vasculature running just superficial to the galea when scoring the aponeurosis. From the Department of Otolaryngology-Head and Neck Surgery, University of Utah, Salt Lake City, Utah
OTOLARYNGOLOGIC CLINICS OF NORTH AMERICA VOLUME 34 NUMBER 3 JUNE 2001
571
572
HOFFMA"
The scalp has a robust and extensively interconnected blood supply (Fig. 1). The scalp is fed by five consistent arteries on each side: (from anterior to posterior) supratrochlear, supraorbital, superficial temporal, posterior auricular, occipital. The superficial temporal also has distinct anterior and posterior branches. These vessels widely and extensively interconnect with some anastomoses extending across the midline. In adults, these vessels permit the formation of long axial flaps that are quite resistant to distal necr~sis.~ In children, however, long axial scalp flaps are at some risk of necrosis and initial delay of the flap may be advisable.6It is thought that pediatric flaps are at greater risk because the galea is less well developed and thus the vessels within the flap are less protected from stretching and attenuation. When designing flaps on the scalp, the surgeon should keep in mind the location of the major axial blood supply and incorporate it within the base of the flap if at all possible. At times, Doppler mapping of the pedicles can be quite helpful especially for long, narrow axial flaps (e.g., Juri flaps). Branches of the first branch of the trigeminal nerve provide the sensory innervation of the scalp anteriorly. The occipital branches of the cervical
Figure 1. Vascular anatomy of the scalp. The major arteries of the scalp are shown along with the rich anastomoses between them. These anastomoses extend across the midline in many locations.
MANAGEMENT OF SCALP DEFECTS
573
nerves posteriorly supply the posterior scalp. Local anesthesia of the scalp easily is obtained with circumferential or crown blocks.
APPROACHES TO RECONSTRUCTION Healing by Secondary Intention
Although often not considered by the reconstructive surgeon, allowing wounds to heal by secondary intention often can be effective in the scalp. The principal drawback of course is that wounds that heal in this manner will not contain hair. Thus, one should consider this option only for those areas that are hairless or are in bald regions. In addition, these scars may be atrophic and have prominent telangiectasis that may be unsightly2 Occasionally, the end result may provide a superior esthetic result when compared with the scars of flap repair. The main disadvantage is the time and attention to wound care that will be required. If the wound is devoid of viable pericranium, then it may be beneficial to create small burr holes through the outer table of cortex down to the diploe that encourages the formation of a bed of granulation tissue. Wound care and protection against desiccation is of primary importance when allowing a wound to heal by secondary intention.
Skin Grafts
In general, skin grafts should be avoided in scalp repair as they give a poor cosmetic result and are prone to bleeding, ulceration and pain. Skin grafts require a viable substrate under them such as intact pericranium or fascia because they typically will not survive over exposed bone alone. If one wishes to employ a skin graft over bone, then one should consider methods to encourage the formation of a bed of granulation tissue first. The skin graft then can be applied after a healthy foundation of granulation has been established. In most cases, a skin graft should be considered as a means of temporary coverage of the scalp while preparing the scalp for a definitive repair with a flap of some sort. If long-term tissue expansion is needed to obtain a flap of adequate area, then it may be beneficial to cover the defect with a temporary skin graft while expansion progresses. Once the flap is ready for elevation and transfer, the graft can be removed and replaced with the prepared flap. Alternatively, one might consider staged, sequential excision of the graft with reconstruction with rotation flaps. A skin graft also may be needed with microsurgical muscle (e.g., rectus), or free flaps, which provide a vascularized cover for the bone but lack skin coverage.
574
HOFFMANN
Hair Replacement Techniques for hair replacement in male pattern baldness are beyond the scope of the article, but some of these can be applicable to traumatic or oncologic scalp defects. In general, scarred tissue does not accept hair transplants well, but in selected patients, they can be successful. Large pedicled flaps can be employed for large areas of alopecia especially along the anterior hairline.'4,'6Micrograft hair transplants harvested from the occipital scalp can be employed successfully in the camouflage of areas of scar or skin grafts that have been given adequate intervals to heal (Fig. Z).'
Figure 2. A, Traumatic partial-thickness avulsion of the occipital scalp. €3, Loss of hair in scar after allowing traumatized area to heal for a few months. C, Appearance after two sessions of micro hair transplants into scarred scalp.
MANAGEMENT OF SCALP DEFECTS
575
Primary Closure Because the scalp is so inelastic, only small defects of a few centimeters or less can usually be closed primarily. Very wide underminingessentially ear to ear and from anterior to posterior hairlines-in a subgaleal plane usually will be required and will be beneficial in reducing standing cone deformities in the thick scalp. Intraoperative tissue expansion and skin closure devices have been advocated as aids to the primary repair of scalp defects.’, l3 Increased wound tension and related alopecia may be a concern with these techniques. Galeal incisions (Fig. 3 ) may be employed to allow enhanced stretch of the wound edges during closure. Typically these are placed parallel to the incision line allowing reduced wound closing tension. Care should be taken to avoid damaging major blood vessels while incising the galea. Occasionally, it may be helpful to transilluminate the flap while planning these galeal incisions, because one may be better able to visualize the course and location of the larger vessels. Tissue Expansion Two distinct types of tissue expansion have been described in the scalp: long-term tissue expansion and intraoperative sustained tissue expansion. These techniques are physiologically and histologically distinct. Long-term, progressive tissue expansion is a widely accepted technique in scalp reconstruction that involves the surgical placement of a Silastic balloon under the galea.7,l2 The balloon gradually is inflated with saline over a period of six to eight weeks until the desired volume is obtained.
Figure 3. Galeal incisions made on undersurface of scalp flap to facilitate closure. These incisions should be made with care to avoid damage to the vascular structures.
576
HOFFMANN
Figure 4. A, Traumatic wound of the forehead and scalp. B and C, Scalp defect seen with tissue expanders in place near completion of expansion. Note the extent of expansion of the surrounding scalp needed. Two expanders are in place superior and posterior to the defect. Illustration continued on opposite page
MANAGEMENT OF SCALP DEFECTS
577
Long-term expansion results in physiologic and morphologic changes in the scalp while increasing the surface area of the f l a ~ . ~A, dense '~ fibrous capsule forms around the expander and blood supply to the scalp is enhanced. This enhanced blood supply in the expanded tissue particularly may be beneficial when developing scalp flaps that have a compromised vascularity (e.g., postirradiation). The overlying epidermis typically does not thin and mitotic activity within the expanded tissue increases. The density of the overlying hairs decreases because the surface area increases while the number of hair follicles remains the same. Alopecia usually does not occur with careful and judicious expansion although there may be some dryness or hyperpigmentation of the skin. The selection of the appropriate size and shape of the expander to be used requires clinical experience and judgment. A rule of thumbI7 for expansion of scalp flaps is to fill the expander to 2 to 2.5 times the size of the defect to be reconstructed (i.e., expand the flap to 16 cm for an 8 cm defect). Crescent or round expanders are employed frequently for scalp flaps. It may be necessary to employ two separate expanders, one on each side of the defect, to obtain the volume needed to get adequate flap expansion. Typically the expander is placed adjacent to the defect and then gradually inflated beginning two weeks after implantation over a period of six to eight weeks. Once the desired amount of expansion is reached, the expander is removed and the flaps are raised and inset (Fig. 4). The scalp is an ideal place for
Figure 4 (Continued). D,Postoperative result after expanded scalp flap repair and forearm free flap to forehead.
578
HOFFMANN
long-term tissue expansion, because the tissue is thick and vascular, thus resistant to exposure or extrusion of the expander-the most common complication. Furthermore, the solid calvarium provides an ideal base for the expander. Intraoperative tissue expansion (ITE)in contrast does not induce physiologic or histologic changes in the kin.'^,^^ ITE is performed in one setting by placing a balloon (or larger Foley catheter) under the galea and inflating it for three cycles of inflation and deflation immediately before flap elevation (Fig. 5). Although not fully understood or accepted, it has been theorized that ITE takes advantage of mechanical creep in the tissues. Creep is a mechanical process in that the interstitial fluid and ground substance is displaced in the expanded tissue and there is fragmentation of elastin and collagen fiber realignment." Some investigators have claimed that ITE is merely a way to enhance undermining and tissue redraping." In any case, ITE may facilitate the raising of scalp flaps but one should only expect an additional 1 to 1.5cm of flap length with this technique and one should be very aware of wound tension with closure of flaps with this te~hnique.'~
Figure 5. A, Mohs defect of the parietal scalp. 19,lntraoperative sustained tissue expansion of rotation flap with large volume foley catheter. C,Flap rotated into place. D, Postoperative result of healed reconstruction.
MANAGEMENT OF SCALP DEFECTS
579
Local Flaps Local rotational or advancement flaps are the mainstays of scalp reconstruction. The flaps follow the same general guidelines as elsewhere in the face except that they typically need to be longer and proportionally larger than other facial flaps because the scalp is so inelastic.' For example, for a defect of 3 cm in width, a rotational flap of 15 to 18 cm may be needed (Fig. 6). The most common design is a broad rotation flap. It is
Figure 6. A, Traumatic avulsion of the parietal scalp. B, Large rotation flap used to close defect. Note that almost the entire scalp was undermined to allow flap rotation and closure. C, Postoperative result with maintenance of hair growth and hairline.
580
HOFFMANN
ideal to design the flap so that a major vascular pedicle will enter the base of the flap. One should also consider the location of the hairline and design the flap so that an incision can be hidden there. In some instances, multiple flaps will be needed to provide adequate tissue (Fig. 7). Regardless of the flap design, one should try to minimize trauma to the hair follicles by making all incisions parallel to them and to utilize forceps or electrocautery judiciously.Most often flaps are elevated in a subgaleal plane with
Figure 7. A, Large Mohs full-thickness defect of the vertex on a bald scalp. B, Two large rotation (pinwheel) flaps designed. Very wide undermining of entire scalp is required for flap rotation and scalp closure. C,Postoperative result.
MANAGEMENT OF SCALP DEFECTS
581
very wide undermining as in primary closure. Galeal incisions can be employed as needed to facilitate wound closure. The galeal sutures that may reduce the pull on the hair follicles and lessen any alopecia typically take up the wound tension. In those cases where an extremely large defect is anticipated, long-term tissue can be successfully employed to provide large surface area flaps with enhanced blood supply. Free Flaps In recent years, microvascular free flaps increasingly have been employed for larger scalp defect^.^,'^ These flaps can provide large areas of vascularized tissue for scalp defects (Fig. 8). Although these flaps are reliable and highly successful, they rarely provide a good esthetic result because of poor tissue match and lack of hair growth. They may be, however, the only option for those cases where a large segment of calvarial bone is exposed and there are no other local or regional flap options. In order to improve the esthetic result, hair transplants and tattooing can be added to free flaps at a later date as desired.
Figure 8. Latissimusdorsi free flap employed for a massive basal cell carcinoma of the scalp and face. An auricular bone-anchored prosthesis and hair transplants are planned.
582
HOFFMANN
References 1. Ahuja RB: Geometric consideration in the design of rotational flaps in the scalp and forehead region. Plast Reconstr Surg 81:900,1988 2. Fosko SW, Branham GH: Reconstruction issues after Mohs surgery. Fac Plast Surg Clin North Am 6:379,1998 3. Furnas H, Lineaweaver WC, Alpert BS, Buncke HJ:Scalp reconstruction by microvascular free tissue transfer. Ann Plast Surg 24:431,1990 4. Johnson TM, Lowe L: Histology and physiology of tissue expansion. J Dermatol Surg Oncol19:1074,1993 5. JuriJ, Juri C: Aesthetic aspects of reconstructive scalp surgery. Clin Plast Surg 8:243,1981 6. Jurkiewicz MJ: Scalp reconstruction with multiple flaps. In Brent B (ed): The Artistry of ReconstructiveSurgery. St Louis, CV Mosby, 1987, p 449 7. Konior RJ, Kridel RWH: Tissue expansion in scalp surgery. Fac Plast Surg Clin North Am 2:203,1994 8. Limmer BL, Buchwach KA: Hair transplantation using follicular unit micrografting. Fac Plast Surg Clin North Am 7523,1999 9. Ling EH, Wang T D Local flaps in forehead and temporal reconstruction. Fac Plast Surg Clin North Am 4:469,1996 10. Lutz BS, Wei FC, Chen HC, et al: Reconstruction of scalp defects with free flaps in 30 cases. Br J Plast Surg 51:186,1998 11. Mackay DR, Saggers GC, Kotval W, et a1 Stretching skin: Undermining is more important than intraoperative expansion. Plast Reconstr Surg 86:722,1990 12. Manders EK, Graham WP, Scheiden MJ, et al: Skin expansion to eliminate large scalp defects. Ann Plast Surg 12:305,1984 13. Mandv SH: Intraoperative expander-assisted scalp reduction. J Dermatol Surp, Oncol 19:lllO-1116 14. Minor LB, Panje WR Malignant neoplasms of the scalp. Otolaryngol Clin North Am 26:279,1993 15. Pasyk KA, Argenta LC, Austed ED: Histopathology of human expanded tissue. Clin Plast Surg 14:435,1987 16. Rousso DE: The use of scalp flaps for frontal alopecia. Fac Plast Surg Clin North Am 2:183, 1994 17. Sasaki GH: Tissue expanders and general guidelines for tissue expansion technique. In Tissue Expansion in Reconstructive and Aesthetic Surgery. St. Louis, Mosby, 1998, pp 11-14 18. Sasaki GH: Intraoperative sustained limited expansion as an immediate reconstructive technique. Clin Plast Surg 14:563,1987 19. Shapiro AL, Hochman M, Thomas JR, Branham G: Effects of intraoperative tissue expansion and skin flaps on wound closing tension. Arch Otolaryngol Head Neck Surg 122:1107,1996 20. Siegert R, Weerda H, Hoffman S, et al: Clinical and experimental evaluation of intermittent intraoperative tissue expansion. Plast Reconstr Surg 92:248,1993 v
Address reprint requests to John F. Hoffmann, MD Department of Otolaryngology-Head and Neck Surgery University of Utah Suite 3C120 50 North Medical Drive Salt Lake City, UT 84132