TITLE: Management of Alopecia
SOURCE: Dept. of Otolaryngology, UTMB, Grand Rounds Presentation
DATE: September 9, 1998
FACULTY: Karen Calhoun, M.D.
RESIDENT: Kyle Kennedy, M.D.
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Alopecia affects both men and women and may result from a variety of causes. The cosmetic consequences may have a substantial emotional impact on the patient. As might be expected, many patients are not in the least content with their hair loss and seek the advice of a physician in search of a remedy. Depending on the cause and extent of the problem, medical and surgical therapies exist which may offer assistance for the patient experiencing alopecia. These modalities may be used alone or in combination, and the particular regimen must be individualized to meet the particular needs of the patient. The physician is obligated to ensure that the patient has a clear understanding of his/her condition and expectations in order for a realistic and thoughtful treatment plan to be devised. This presentation will consider the etiology of alopecia and patient selection with an emphasis on the medical and surgical management of the disorder.
Etiology of Alopecia
Alopecia may occur as a result of trauma, burns, neoplasms, autoimmune disorders, chemotherapy, or dermatologic conditions. However, androgenetic alopecia (AA) is the most common cause of alopecia in both men and women. The three forms of androgenetic alopecia which are recognized include male pattern androgenetic alopecia (MPAA), female pattern androgenetic alopecia (FPAA), and diffuse androgenetic alopecia.
MPAA typically ensues with recession of the hairline in the frontotemporal region. Thinning then occurs in the crown/vertex with subsequent confluence of the two areas. An area of hair-bearing scalp then remains in the temporoparietal and occipital regions. FPAA differs from MPAA in that the frontal hairline is typically maintained while thinning occurs in the crown/vertex. Rarely, thinning may occur simultaneously over the entire scalp as seen in diffuse AA. MPAA may occasionally be seen in women with normal androgen levels, and FPAA may be encountered in hormonally normal men.
Caucasians are most often affected by AA, and the mode of inheritance is unclear. All forms of AA represent a change from terminal hairs to vellus hairs in the alopecic portion of the scalp. While an inherited predisposition is essential for the development of AA, AA will only manifest itself in the presence of androgens. In the alopecic scalp, regional variation in the sensitivity to the effect of androgens is observed.
Dihydrotestosterone (DHT), produced in the skin from testosterone by the action of 5 alpha-reductase, plays the main role in the development of alopecia. The mechanism by which androgens affect hair follicles in the scalp has not been clearly established. Androgens enter the follicular cells and bind to the androgen receptor in the cytosol. The androgen-androgen receptor complex is then translocated into the nucleus of the cell to effect modification of the cellís biosynthetic activities. Various metabolic differences have been identified in balding versus non-balding scalp. The androgen receptor apparently exists in a more active monomer form capable of binding and translocating DHT and an inactive tetramer form. The monomer:tetramer ratio has been found to be higher in balding scalp. While the relative importance of these mechanisms are unclear, they may explain some of the differences in the various patterns of AA and the intersex differences seen in males and females. Alopecia is one of the most common manifestations of hyperandrogenism, but increased levels of androgens are not necessary for the development of AA.
Evaluation of a patient as a possible candidate for hair replacement begins, as always, with a careful history and physical examination. As with other types of elective cosmetic procedures a careful assessment of the patientís motivations and expectations should be performed. If any doubt exists as to the patientís emotional stability, a psychiatric consultation may be warranted. A thorough and frank discussion of the treatment options and limitations should be undertaken, and the physician must be certain that the patientís treatment goals and expectations are reasonable.
A clear assessment of the patientís pattern of alopecia is necessary. However, given the progressive and unpredictable nature of MPAA, this can be quite difficult, if not impossible. This is especially true of the younger patient, in whom future patterns of balding may be almost completely unforeseeable. For this reason, a conservative approach is most prudent. If there is any question as to the ultimate impact that a particular procedure may achieve in light of future patterns of balding, then the procedure should not be undertaken. The final outcome cannot be fully appreciated until the patient has finished balding, and this may be decades from when the procedure is often performed. The Norwood classification is commonly used to characterize the degree of alopecia for purposes of comparison. The spectrum ranges from Norwood class I, depicted by mild frontotemporal recession, to class VII, depicted by only a narrow fringe of hair-bearing scalp in the temporoparietal and occipital regions.
The frontal hairline and potential hair donor areas should be assessed. The frontal hairline, especially in more mature patients, is notable for a triangular area at the junction of the frontal and temporal hairlines, the so-called frontotemporal triangle. The apex of the triangle represents the most lateral aspect of the frontal hairline and should be located at a point even with a vertical line extended superiorly from the lateral canthus. The triangle is formed as the frontal hairline recedes superiorly and the temporal hairline recedes posteriorly. The frontal hairline is naturally convex with the lowest central point at the level of the frontotemporal triangle. The quantity and quality of donor hair is assessed in the temporal and occipital regions. Appropriate density is necessary to provide adequate coverage of alopecic scalp and still render donor site post-operative changes undetectable. Light gray, salt and pepper, blonde, or reddish hair typically yield the best results during transplantation due to the minimal contrast between hair and scalp while the combination of dark hair and light skin are the least desirable.
Older patients are usually better candidates for surgical hair replacement simply because they have a more established pattern of baldness, and fewer unknowns exist. In addition, there is somewhat more laxity of the scalp in older patients. Only a finite amount of donor hair exists. In hair replacement surgery, a paradoxical relationship exists in which the more one needs to cover a given area of alopecic scalp, the less donor material one has available to perform the task. The worst of all possible outcomes is that in which an "unfinished" patient and their physician are faced with no further availability of donor hair as it has all been harvested. Treatment options for alopecia include medical management and both non-surgical and surgical hair replacement.
A number of medications affect hair growth by interfering in some way with androgen metabolism or activity while others achieve their effects in different ways by acting as biologic response modifiers. The effects that these medications have on hair growth have typically been discovered incidentally during use of the medications for the management of other conditions.
Antiandrogens include the following:
The majority of the antiandrogens are limited to use in women due to their potential for feminization, decreased libido, and impotence in men. Finasteride (Propecia) is a 5 alpha-reductase inhibitor that also weakly binds the androgen receptor. It was originally approved for use in the treatment of benign prostatic hypertrophy and has recently become available for oral use in the management of alopecia. A significant number of patients have demonstrated retarded hair loss and renewed hair growth with this medication.
The biologic response modifiers are represented by minoxidil (Rogaine), a potassium channel agonist and potent peripheral arteriolar vasodilator. The mechanism of action in the management of alopecia is unclear, but the medication has been observed to retard hair loss and reverse the balding process in some patients. It is approved for use as a 2% topical solution.
Surgical hair restoration may involve coverage of alopecic scalp with donor hair, reduction in the amount of alopecic scalp, or a combination of these two modalities.
Punch-Graft Hair Transplantation
Autografts of hair may be transplanted from an adequate scalp donor site to an alopecic portion of the scalp to provide coverage. The autografts consist of plugs of scalp tissue containing epidermis, dermis, and subcutaneous tissue with viable hair follicles. Standard plugs are typically 4 mm in diameter and are obtained from the lateral and posterior aspects of the scalp. These areas must contain terminal hairs of acceptable density to provide sufficient coverage at the recipient site in the frontotemporal and midscalp areas. Approximately four grafting sessions are typically required to cover most alopecic areas. The grafts retain the characteristics of the donor site.
Care must be taken in assessing the adequacy of potential donor sites in light of the progressive and unpredictable nature of androgenetic alopecia. This is particularly important in the younger patient, in whom future patterns of balding are difficult if not impossible to determine prospectively. The anterior boundary of the safe area for the donor site is usually established as a vertical line through the external auditory canal. The superior extent of the safe area for the donor site in the midoccipital region is usually demarcated as a horizontal line through a point 2 cm superior to the superior attachment of the auricle.
Following selection of an appropriate donor site, the scalp is infiltrated with a sterile saline solution to provide additional stability of the tissues and minimize potential shearing. The hair is trimmed to a length of approximately 2 mm. Autografts are obtained with a sharp 4 mm carbide steel surgical trephine using a hand engine set at approximately 5,000 rpm. Care is taken to obtain the plugs of tissue at an orientation parallel to the hair follicles to prevent damage to the follicles. The most inconspicuous donor site is usually established by harvesting the plugs in a continuous, horizontally-oriented fashion. Subcutaneous tissue is incised deep to the hair follicles in a plane parallel to the skin surface while maintaining a 1 mm thick layer of subcutaneous fat below the follicles. Any excess tissue, skin tags, or severed hair shafts are removed. The autografts are set aside on sterile gauze soaked with Ringerís lactate, and the donor site is closed. In the Pierce technique of donor site closure, any remaining cutaneous bridges of tissue are incised, and opposite sides of the incision are advanced in opposite directions to allow interdigitation of the sawtoothed edges. Subsequent wound closure results in a linear incision line.
At the recipient site, autografts may be transplanted into slits or holes. Recipient holes are usually obtained with a punch 0.25 to 0.75 mm smaller than that used to obtain the grafts to allow for shrinkage of the grafts. The grafts are inset in rows while maintaining a consistent intervening area of scalp equal to the diameter of the recipient holes to provide for adequate circulation. Orientation of the recipient holes parallels the orientation of the follicles themselves, and every attempt is made to recreate the natural orientation of the hair in the particular portion of the scalp being covered. Approximately 6 weeks are allowed to elapse between the first and second transplant sessions. Hair growth is usually not observed at the transplanted site for about 12 weeks, and hair may even be lost at the site in the initial post-operative weeks. An assessment of the quantity and quality of the hair growth should be performed prior to planning future grafting sessions.
Smaller autografts may be obtained depending on the coverage requirements of the recipient site to be transplanted. Minigrafts contain 3 to 8 hairs each and are typically obtained from quadrisection of 4.5 mm diameter punch grafts. Micrografts contain 1 to 2 hairs each and may be fashioned by sharply excising follicle-containing tissue from the periphery of standard punch grafts. These grafts may be transplanted in areas requiring coverage which is more sparse or in areas where it is necessary to blend and taper the margins of areas previously transplanted with standard grafts.
Various patterns of excision have been proposed for scalp reduction, but all have the common goal of reducing the amount of alopecic scalp. The degree of scalp flexibility is an important predictor of the success of this procedure. This maneuver provides for a smaller area which must be transplanted and effectively reduces the recipient:donor ratio. Scalp reduction is usually employed as an adjunct to hair transplantation and may be performed before, during, or after such procedures. Most reductions are performed in the prone position with local anesthesia and intravenous sedation. Approximately 6 weeks should be allowed to elapse between procedures to avoid compromise of the vascular supply. Scalp reduction attempts to elevate the temporal fringes toward, if not to, a point at which they would meet in the midline of the scalp with elimination of the entire bald area if possible. The ultimate design of specific procedures must be tailored to meet the needs of the individual alopecic patient. The ideal patient is perhaps the older patient with a stable mild to moderate bald area in the crown/vertex area.
The midline sagittal ellipse pattern is perhaps the least difficult to perform. The incision is carried down through the skin and subcutaneous tissues as well as through the galea aponeurotica. The scalp is then elevated in a subgaleal plane down to the superior attachments of the auricles and the nuchal ridge. Scalp flaps are advanced, and excess alopecic scalp is excised followed by tension-free wound closure in two layers. A potential disadvantage of this pattern is formation of a central scar with a slot extending into the midoccipital donor area. This may require transplantation for camouflage. An unnatural direction of the hair in the area occurs as well.
In general, the Y pattern is more difficult to perform than the midline sagittal ellipse but allows for the excision of a larger amount of alopecic scalp in the crown region. More flexibility in the design of the excision is possible, and a slot deformity in the midoccipital region is avoided. A more natural hair direction is also preserved.
Lateral patterns may be quite variable in design, and C, J, S, and crescent patterns have been employed. Natural hair direction is typically maintained, and the midoccipital slot is avoided. These excisions are somewhat technically more difficult to perform and are associated with an increased incidence of central scalp hypoesthesia.
Extensive Scalp Reduction
Extensive scalp reductions differ from standard scalp reduction procedures principally in the degree of undermining which is required. The bilateral occipitoparietal (BOP) and bitemporal (BT) flaps have been employed in extensive scalp reductions. These flaps have been developed for the management of extensive alopecic areas in the midscalp and crown regions in patients of Norwood class IV to VI. A combination of 2 to 3 procedures is usually required, and the BOP flap is typically performed as the initial procedure. After an interval of 2 to 3 months the BT flap may then be performed. Alopecia remains in the frontal region and is subsequently managed with punch-graft hair transplantation for recreation of the frontal hairline. A BT flap alone may be employed in those patients with a more limited area of alopecia in the crown region. Both the BOP and BT flaps require ligation of the occipital artery approximately 2 to 6 weeks prior to the definitive flap procedure, and this minimizes the risk of subsequent scalp necrosis. Patients with limited scalp flexibility may require two BOP flaps prior to the performance of the BT flap.
The BOP flap procedure begins with identification of the course of the superficial temporal artery. A vertical skin incision is then placed anterior to the artery at the level of the superior attachment of the auricle. The incision lies posterior to the hairline in the temporal region and is carried superior to the temporal fringe. From there, the incision extends posteriorly along the temporoparietal and occipital fringe. A similar incision is placed on the contralateral side. The scalp flap is elevated inferiorly to the auricle and onto the posterior aspect of the conchal cartilage. The scalp over the mastoid is elevated in a superficial subcutaneous plane. Posteriorly, the scalp is elevated over the nuchal ridge with incision of the origin of the occipitalis and galea aponeurotica. Elevation extends into the nuchal region with mobilization of the entire hair-bearing scalp. The scalp flap may then be advanced anteriorly and superomedially with excision of the overlapping alopecic areas. Wound closure is then performed in two layers. The BT flap is performed in a similar fashion except that the posterior portion of the scalp excision veers posterolaterally into the occipital hairline to recreate a natural cowlick.
The extensive scalp reduction procedures are associated with an increased incidence of complications as compared with standard scalp reductions. The vascular supply of the more extensive flaps is more tenuous with an increased possibility of necrosis. This is alleviated to a degree by ligation of the occipital artery several weeks prior to creation of the flap. Widening of the scar in the midscalp region is a concern as is potential poor scar formation and/or scar exposure in the area of the temporal hairline. These areas may require transplantation with minigrafts, but meticulous surgical technique and thoughtful preoperative planning should minimize the potential for this type of outcome.
The use of tissue expanders is another means by which patients requiring scalp reduction or advancement of hair-bearing flaps may be managed, particularly if these maneuvers are hindered by limited scalp mobility. In stretching the overlying scalp, tissue expanders distribute hair over a wider surface area of the donor regions of the scalp. A variety of expanders are available, and these are typically banana or horseshoe-shaped. They may be tailored to meet the needs of the individual patient. Incisions are placed along the temporoparietal and occipital fringe, and the scalp is elevated in these areas. The expanders are inserted and positioned flat against the periosteum. Sterile saline is injected via remote injection ports placed beneath the alopecic midscalp area to alleviate the dead space.
Tissue expansion is begun about 2 to 3 weeks following insertion of the expanders and 30 to 60 ml of sterile saline is injected 2 to 3 times per week. The expanders are gradually filled over a period of 6 to 8 weeks until adequate domes of tissue are developed over the expanders to address the alopecic area which is present.
After adequate expansion, the expanders are then partially deflated, and an incision is begun in the area of the frontotemporal triangle. Removal of the expanders is performed, and the incision is carried around the fringe of the temporoparietal and occipital regions. Hair-bearing flaps may then be advanced superiorly with excision of overlapping alopecic scalp and approximation of the flaps in the midline. Additional advancement of the flaps may be achieved with incision of the capsule followed by further undermining inferiorly.
Disadvantages of tissue expansion include the need for repeated injections of saline and the discomfort associated with the injections, as well as temporary deformity of the scalp. Potential complications are bleeding, hematoma, expander extrusion, and expander failure.
In patients with substantial frontal baldness, transposition flaps provide a relatively rapid method for restoration of the frontal hairline. The Juri flap is an example of a transposition flap used for this purpose. It is pedicled on the superficial temporal artery and requires several stages for completion. The superficial temporal artery is identified approximately 3 cm above the superior helical root, and the flap and frontal hairline are designed. Flap width is 4 cm, and the flap length is determined by the distance needed to reach the distal end of the frontal hairline in the contralateral frontotemporal region. An additional 4 cm is added to the length of the flap to compensate for the standing cone which results from transposition of the flap. The flap is curved posterosuperiorly into the temporal region from its base 3 cm above the superior helical root. The flap then curves posteroinferiorly into the parietal and occipital regions.
Incision of the skin is performed along the proximal 3/4 of the flap down through the galea, but no elevation is performed. One week later, the distal 1/4 of the skin incision is performed with elevation in the subgaleal plane up to the distal limit of the previous weekís procedure. The flap is then laid back down. After another week has elapsed, elevation of the flap is completed in the subgaleal plane, and the donor site is widely undermined and closed in two layers. An incision is made along the frontal hairline, and the flap is transposed. Prior to inset of the flap, a 1 mm strip of epidermis is sharply excised from the hairline aspect of the flap. The dermis thus exposed is buried beneath the cut edge of the forehead skin to camouflage the scar during hair regrowth in this area. The overlapping strip of alopecic scalp posterior to the flap is excised. Six weeks following transposition of the flap, the resultant standing cone may be revised along with recreation of a frontotemporal triangle symmetric to that of the contralateral side. If necessary, an additional flap may be transposed posterior to the original one 2 to 3 months later.
Flap procedures are more likely to involve complications than other types of surgical hair restoration, and these may include necrosis, bleeding, hematoma, infection, scar widening, and poor hairline design.
Complications such as bleeding, scarring, infection, and hematoma are potential complications of nearly any surgical procedure. Certain complications, however, are especially pertinent to hair replacement surgery. Some have already been mentioned during the discussion of the procedures themselves. Most may be addressed or prevented with meticulous attention to detail during surgery.
Cobblestoning, compression, and delling/divot formation are the result of improper matching of grafts with their recipient sites. Cysts may form as a result of retained foreign body or epidermal inclusion. Telogen effluvium or shock hair loss is a phenomenon which is an ordinary occurrence following hair transplant surgery and usually resolves 3 to 4 months post-operatively. Folliculitis is less common and may especially be seen in patients with a history of pseudofolliculitis barbae. Formation of arteriorvenous fistulae may become troublesome with progressive enlargement. These may require ligation for management.
When performing hair transplant surgery, hairlines may be inappropriately placed or shaped, hair orientation may be misdirected. Stretch-back, necrosis, and slot defects may play a prominent role when scalp reductions or flaps are performed. Proper flap or reduction design and tension-free wound closure may alleviate these problems.
A realistic treatment plan devised with respect to the individual patientís expectations and circumstances is essential. With the progressive and unpredictable nature of MPAA, a conservative approach is necessary to avoid undesirable results for decades to come following procedures for the surgical management of alopecia. Long-term commitment for both the patient and physician provides the foundation for a treatment plan whose final outcome may not become evident for years. The physician must make it an imperative to strive for the best and yet expect the worst when attempting to prognosticate with regard to a given patientís future balding patterns in order to minimize the potential for undesirable outcomes. Finally, it should always, always be kept in mind that when it comes to surgical hair restoration, the more you need, the less you are likely to have. Therefore, plan accordingly.
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Marrit E, Konior RJ. Patient selection, candidacy, and treatment plan for hair replacement surgery. Fac Plast Surg Clin North Am. 1994;2(2):111-137.
Stough DB, Randall JK, Schauder CS. Complications in hair replacement surgery. Fac Plast Surg Clin North Am. 1994;2(2):219-229.