Intricacies of the Single-Scar Technique for Donor Harvesting in Hair Transplantation Surgery

FROM HAIR transplantation's simple beginnings, the concept of removing cylindrical areas of donor scalp and letting them heal by secondary intention was a crude one at best¹ (Figure 1). The sad part about this realization is that today the average result at the donor site has improved, but there are still too many patients with either one thick unsightly scar or many finer scars over the back of the head. Conversely, it is the author's opinion that the average result at the recipient site is consistently much better than it was years ago having progressed from the 5-mm plug² to the fine art of follicular unit transplantation.^3-5

According to the writing of Stough and Haber,⁶ the three most common donor site approaches utilized by hair restoration surgeons today are (1) the traditional donor strip-harvesting technique, (2) the refined donor strip-harvesting technique, and (3) the single-scar technique. All of these approaches can be performed with the multibladed knife (multiple thin strip excision) (Bassacia E, Scarborough D, paper presented at the 17th Annual Scientific and Clinical Meeting of the American Society of Dermatologic Surgery, Maui, Hawaii, February 13-17, 1990)^7,8 or with a No. 10 Bard Parker blade (fusiform excision).⁹

traditional donor harvesting technique involves taking the initial horizontal donor strip at the midpoint between the ears. The following three sessions are then taken immediately above or below the initial harvest (Figure 2). If additional hair is needed for additional sessions, this hair is extracted from strips made from the parietal zones. It is the author's view that the primary problem with this technique is that it leaves patients with many scars over the back of the head, which can cause a severe cosmetic deformity and will have a negative impact on the ultimate number of hairs available for harvesting.

The refined donor harvesting technique differs from the traditional donor harvesting technique in that lateral incisions are begun at the parietal areas and are brought toward the midline (Figure 3). This technique differs from the traditional technique in that the latter method does not harvest the parietal areas until later sessions. Although hailed by some authors as an improvement over the traditional technique, this technique also leaves patients with a large potential for cosmetic deformity in the donor site owing to the great number of scars (Figure 4). Additionally, because multiple scars are present, the ultimate number of follicular units available for future harvesting will be limited.

Figure 1. Multiple cylindrical scars from the very early days of open donor harvesting techniques.

The single-scar techniques¹⁰ was first introduced to the literature in the 1970s by Coiffman¹⁰ and reintroduced by Unger¹¹ and Brandy¹². Although the concept of leaving only one scar after multiple surgeries seems the most logical, it is only practiced by approximately half of hair restoration surgeons. This method involves the harvesting of a single long fusiform, which is taken from the left parietal area across the occipital region and back over to the right parietal scalp (Figures 5A-G). All subsequent fusiform harvests are performed immediately superior to the previous scar with the inferior incision of the fusiform lying immediately below the previous scar. If performed properly, this technique leaves one aesthetically pleasing scar regardless of the number of sessions performed (Figure 6). There are, however, many intricacies to making this procedure work well which is the discussion of this article.

SURGICAL PREPARATION

The most important areas to examine before a patient's initial surgery are the upper occipital, parietal, postauricular, and nape regions, because these areas can develop baldness in later years and create significant cosmetic problems if not accurately examined. It is the author's opinion that areas of future hair loss can be fairly well determined in most patients if the hair is thoroughly soaked with alcohol or water and is subsequently roughed up. In the large majority of patients a line delineating the male pattern can be found. This line of demarcation becomes noticeable early in the male pattern baldness process owing to hypopigmentation, decreased shaft diameter, and increased fraying of the cuticle that occurs to the hair shaft. It is obviously impossible to estimate exactly where future hair loss will progress in all patients, but the author feels very strongly that this skill can be developed with practice. The key is for the surgeon to get into a habit of actively searching for this line of demarcation on every single patient. If greater accuracy is desired, a densitometer can be utilized to diagnose the line of change between resistant donor dominant hair and the hair undergoing early miniaturization. As previously alluded to, neither approach can guarantee where future hair loss will progress, so it is critical to be conservative with all determinations.

Once the area of future hair loss is estimated, the author takes a scribe and draws a line at the male pattern line of demarcation (Figure 7). Upon completion of determining this line, the area to be harvested for the first session is drawn. A 1 x 20-cm fusiform is the average size of the donor harvest, which is scribed at the inferior-most portion of the donor area where the hair is of good quality. Dots are made 1 cm apart along the fusiform. These dots will dictate the placement of the vertical 30-gauge needle stabs of 1% lidocaine hydrochloride with 1:100,000 epinephrine later in the procedure. This first donor harvest is usually made immediately below or over the occipital protuberance with the lateral tips of the fusiform being at least I cm above the periauricular hairline.

Four months later when a second session is required, a fusiform is drawn in such a way that the bottom edge of the fusiform is immediately below the previous scar line and the superior line is drawn approximately 1.2 cm above the inferior line. This harvest is 2 mm wider than the initial harvest so that the previous scar can be removed while accomplishing 1 cm of width for the donor harvest. It is also important to draw a line approximately 2 to 3 cm below the inferior line of the fusiform (Figure 8). This is done in preparation for subcutaneous infiltration of 0.25% lidocaine hydrochloride with 1:400,000 epinephrine so that undermining can proceed inferiorly beyond the inferior scar.

During a third procedure the exact same procedure as that for the second session would be performed. All other procedures would follow the same protocol.

SURGICAL PROCEDURE

First Session
The patient is scribed as delineated in the previous section. Lidocaine hydrochloride 1 % with 1:100,000 epinephrine is injected into the lines of the fusiform. These are injected with a 30-gauge needle vertically into the dots previously made at the time of the scribing. Injections are subsequently made in between the dots. A solution of plain saline with 1:100,000 epinephrine is then injected throughout the fusiform for vasoconstriction and the development of turgidity.

Once anesthesia has taken effect, a No. 10 Bard Parker blade is utilized to excise away the 1.0 x 20-cm fusiform from the undersurface. With the support of 2.5 X magnification, the author undercuts, as superficially as possible, in the subcutaneous layer so that deeper nerves and vessels are not damaged. The author also feels that it is important to cauterize with the help of magnification so that hair follicles are not injured. After completion, the area is temporarily approximated with staples (Figure 9) and then is closed into two layers: a subcutaneous/galeal closure with 2-0 polydoxinanone and 5-0 fast absorbing gut for cutaneous approximation. It is the author's opinion that the superficial closure be performed with some type of magnification (preferably 2.5 x or greater) and be performed so that the bites are no deeper than 2 mm and no further away for the incision line than 2 mm (Figure 10). It is also important to note that the author uses staples only as an approximation tool primarily because they do not allow the surgeon the accuracy that the aforementioned technique allows.

Second Session
As previously mentioned, this procedure will require undermining to remove the scar and achieve the harvesting required. After anesthesia, the fusiform is excised. To accomplish successful undermining, it is essential that the head be placed into a Pron Pillo (Ellis Instruments, Chatham, NJ). This position allows for the surgeon's hands to be in a neutral position and permits excellent visibility (Figure 11). Conversely, a sitting position totally negates the surgeon's ability to easily visualize the undermined pocked and it also puts the surgeon's hands into a very awkward position (Figure 12). The undermining technique is carried through with the assistant pulling the scalp in the area to be undermined with one hand and holding the head down with the other. The surgeon utilizes the end of his or her suction device to elevate the flap with tension, while keeping the field clean of blood (Figure 13).

If after undermining 1 to 2 cm the surgeon still finds it difficult to close the wound, the scar tissue from the previous surgery can be removed with cut cautery or a scissor from the underlying muscle (Figure 14). Frequently this is all that is needed to allow the closure to occur without tension. If after this maneuver there is still some tension, it may be necessary to undermine an extra centimeter or two to gain a loose closure. It may also be necessary at times to release the skin in the postautricular region because this maneuver releases a great amount of tension (Figure 15).

Third and All Subsequent Sessions
These sessions are performed identically to the second session.

DISCUSSION

The question the author has often asked himself over the past several years is, "Why don't more than half of all surgeons use a single-scar technique?" This question has been asked over and over again because many of the patients that the author sees from other very reputable hair restoration surgeons have either one thick scar or multiple finer scars on the backs of their heads. These patients are happy with their recipient result, but are unhappy with the donor site. Their main complaint is that they do not feel comfortable being in the wind, driving a convertible, going on a boat or engaging in other activities where a thick single scar or multiple scars may show.

Why don't more than half all surgeons use a single-scar technique? After communicating with several hair restoration surgeons about this issue, the following factors seem to be a recurring theme as to why the single scar technique is not utilized as often as one might think:

1. The surgeon feels that it adds too much time to the procedure.
2. The surgeon is not familiar with the anatomy below the nuchal line.
3. The surgeon uses a sitting position for his or her surgical technique, which significantly negates the ability of he/she to visualize the subcutaneous and subgaleal space to be undermined. The hand is also in a very uncomfortable position, which does not allow for easy undermining.
4. The surgeon is fearful of undermining into the postauricular area and the regions overlying the trapezius muscle.

When looking at each reason independently and analyzing it, one begins to realize that the aforementioned roadblocks can be over come easily.

The surgeon feels that it adds time to the procedure

The time of undermining is the only element that will add time to the procedure. If the procedure is performed in a Pron Pillo, every centimeter of undermining should add an extra 5 min once experience is gained. For example, if a 2-cm area is undermined, it adds approximately 10 min to the procedure.

The surgeon is not familiar with the anatomy below the nuchal line

The anatomy below the nuchal line consists primarily of the trapezius muscle and the sternocleidomastoid muscle. There are small perforating vessels throughout this area, but these vessels are very small and insignificant. If the surgeon stays in the fat layer below the hair follicles, it is almost impossible to cut one of these vessels. The technique described in this article helps make the anatomy highly visible. The assistant pulls the hair in the area being undermined with one hand and holds the head down with the other hand while the surgeon elevates the underscalp with the end of a suction device, which also helps to stretch the scalp and clean the field. It is the author's opinion that it is wise to use some type of magnification (preferably 2.5 x or greater) while undermining so that the overlying hair follicles can be visualized.

The surgeon uses the sitting position for his or her surgical technique

This problem can be alleviated immediately by purchasing a Pron Pillo. This pillow is very comfortable for the patient and allows the surgeon to maintain a neutral hand position while obtaining excellent visibility.

The surgeon is fearful of undermining into the postauricular area and the regions overlying the trapezius muscle

This reason is similar to the second reason and is the result of not understanding that the anatomy below the nuchal ridge.

One of the most important anatomic facts to understand is that the scalp below the nuchal ridge does not have galea aponeuritica. Because of this fact, the skin is much more mobile than a scalp that has restrictive galea under its surface (Figure 16). That is one of the primary reasons that the first fusiform is taken as low as possible where the hair is of good quality. Conversely, if one were to take the initial fusiform in a much higher position, one would be undermining inferiorly and superiorly in areas that have restrictive galea on the undersurface. This reality would significantly resist the mobility of the scalp from both the superior and the inferior aspects and create a tight closure with subsequent wide scarring.

In regard to the use of staples versus sutures for the cutaneous closure, it has been proposed by some surgeons that staples give a better closure than a suturing technique. This is probably true for some surgeons. Nevertheless, it is the author's opinion that if 2.5 x or greater magnification is used for a two-layered closure and cutaneous bites are taken no more than 2 mm deep and 2 mm wide, the approximation is much more precise when compared to staples and hair follicles are not strangulated. Conversely, if a surgeon uses his or her naked eye for approximation and takes wide and deep bites through the scalp, the stapled approach will probably yield better results for that given surgeon. There can be very little argument, however, that if an observer had a microscopic view of the aforementioned 2.5 x or greater magnified approach and a gross staple technique, the former approach would consistently create a more perfect coaptation. It is well known that all cardiovascular surgeons use strong magnification when performing anastamoses of coronary blood vessels because the precision of the closure is greatly enhanced. Hair restoration surgeons should also maximize their techniques to ensure the highest probability for success. It is widely accepted by the hair restoration community that magnification (even microscopic magnification) be utilized for creating follicular units. The author thinks that similar care should be taken with donor site closures.

SUMMARY

The author presents some of the intricacies that facilitate the single-scar donor harvesting technique for follicular unit hair transplantation. Approximately half of all surgeons shy away from this technique because they use a sitting position for harvesting, which places the hand in a very unnatural position and severely limits visualization during the procedure. These surgeons also state that increased undermining is more time-consuming, and they do not feel comfortable with the anatomy inferior to the nuchal ridge. This article addresses these concerns and suggests ways to remove these obstacles, which will consistently lead readers to a single, aesthetically pleasing scar after multiple donor harvests.

REFERENCES

1. Orentreich N. Autografts in alopecia and other selected dermatological conditions. Ann N Y Acad Sci 1959;83:463-79.
2. Norwood OT. Five-millimeter grafts. In: Norwood OT, ed. Hair Transplant Surgery, 1st ed. Springfield (IL): Charles C. Thomas, 1973:94-5.
3. Limmer BI. Elliptical donor stereosclopically assisted micrografting as an approach to further refinement in hair transplantation. J Dermatol Surg Oncol 1994;20:789-93.
4. Bernstein RM, Rassman WR. The logic of follicular unit transplantation. Dermatol Clin 1999;17:277.
5. Bernstein RM, Rassman WR, Szaniawski W, Halperin AJ.
Follicular transplantation. Int J Aesth Res Surg 1995;3:119-32.
6. Stough DB, Haber RS. The donor site. In: Stough D, Haber RS, ed. Hair Replacement: Surgical and Medical. St Louis: Mosby Year Book, 1996:139-40.
7. Brandy DA, A. new instrument for the expedient production of minigrafts. J Dermatol Surg Oncol 1992;18:487-92.
8. Stough DB. Hair transplantation by the feathering zone technique. new tools for the nineties. Am J Cosm Surg 1992;8:243-8.
9. Limmer BI. Elliptical donor harvesting. In: Stough DB, Haber RS, eds. Hair Replacement: Surgical and Medical. St Louis: Mosby Year Book, 1996:142-7.
10. Coiffman F. Use of square scalp graft for male pattern baldness. In: Unger WP, eds. Hair Transplantation, 1st ed. New York: Dekker, 1979:159-63.
11. Unger WP. Total excision techniques in the donor area harvesting for hair transplanting. Am J Cosm Surg 1994;11:15-22.
12. Brandy DA. A single scar technique for donor harvesting in hair transplantation surgery. Am J Cosm Surg 1996;13:19-22.

COMMENTARY

Brandy reviews a variety of patterns of donor harvesting that result in multiple rows of scars. His reference for them is Stough's text¹ that was published 7 years ago and which, per usual, contained information written at least 1 year before the publication date. To put the problem in perspective, 7 or 8 years later, it should be recognized that very few surgeons are currently using as many donor sites as described in that text. Unfortunately, however, many are still employing three or four donor areas and I agree that those numbers are too high. The first to describe a single donor area and scar excision technique was Dr Felipe Coiffman who described the use of elliptical donor area excisions and the excision of scars from previous harvests as part of subsequent ones in the 1970s. He published this approach in the first edition of Hair Transplantation in 1979². Sadly, everybody else—including me—ignored his suggestion for at least a dozen years. (In 1994 I published an article in which I too recommended the reexcision of previous donor site scars as part of the rational harvesting of donor sites.³) I had also been employing the concept and speaking about it at meetings for several years before that. Not only are additional scars in the donor area potentially noticeable, there are other clinically significant consequences on blood supply, closing tension, and tension after edema develops in the donor area that Brandy does not discuss in this article but that re-reinforce his recommendation. These are fully described in the 4th edition of Hair Transplantation to be published in fall 2003⁴. In brief, a donor site excised superior to a scar from a prior donor site has its blood supply cut off to its interior flap by the previous scar. A donor site excised from inferior to a previous donor site has its blood supply to the superior flap cutoff by the scar superior to it. Scar tissue also binds down the skin overlying it and therefore will often increase closing tension. Both of these factors increase the possibility of a less than optimal scar from donor strips taken from superior to inferior to previous scars. Furthermore, because of the binding down of the skin by scar tissue, as edema develops over the postoperative period, the fluid is less free to dissipate through the adjacent tissue and much more tension develops at the site of closure; thus, another reason for wider scars is introduced. The cosmetic importance of postoperative facial edema is well recognized whereas the importance of postoperative edema in the donor area has not been sufficiently appreciated. For all of these reasons, it is a good idea to limit oneself to one or, at most, two scars in the donor area. In most of my patients, I currently use a single donor site and produce a single scar following, more or less, a type of procedure similar to that described in this article by Brandy. I differ in that I take the first donor strip through the densest portion of the rim hair rather than from the most inferior area of what I and Brandy guess will maintain adequate long-term hair density. Our guess could be wrong. The densest area of the rim therefore is safest with regard to long-term good donor area hair density. The prior scar is centered in the new donor strip. This makes the preparation of grafts from the strip more difficult because of the distortion of hair angle caused by the adjacent scar tissue. Nevertheless, the extra time and effort necessary seems well worthwhile to me because it means the strip will always be taken from that part of the donor area that is safest from the possibility of future thinning.

In some patients I have, for many years, used two donor sites because I am looking for different textures and colors of hair, but I never produce more than two scars⁵. In such cases, I do guess at how far inferiorly I can go without entering an area where the hair density may decrease to unacceptable levels with the passage of time. For this reason I employ two donor areas primarily in patients who are 40 years old or older. If I do produce two scars, they are at least 2 cm apart so that the potential problems described above are less likely to develop. A more important point of difference between Brandy's approach and mine, however, is that I, and many others, use narrower strips than he typically does. Usually my strips are no wider than 8 to 9 mm as opposed to his 10 to 12 mm. There are many reasons for this difference and space does not allow for a full discussion here; however, again, it is described, in detail, in the chapter on the donor area in the upcoming 4th edition of Hair Transplantation. A strip that is 1 to 3 mm wider than another might, at first, not seem like much of a difference. Nevertheless, in my experience I have found that once there is even slight closing tension, adding an additional 1 or 2 mm to the width of a strip results in an exponential increase in closing tension. As noted above, this added tension is further enhanced by postoperative donor area edema. I believe that the combination of "slightly wider" donor strips and postoperative donor area edema is the most frequent cause of "unexpectedly" wide donor scars. One of the important advantages of narrower strips is that double-layer closure becomes unnecessary in virtually all cases and undermining of both flaps also becomes unnecessary in most patients. It is to be remembered that when a flap is undermined blood vessels are severed (regardless of the level of undermining), as well as nerves. The blood supply to the healing wound is thereby somewhat decreased and postoperative pain may also be increased-especially if cauterization of vessels (and inevitably their adjacent nerves) must be carried out because of bleeding from the undermining. If the surgeon takes a narrower strip than that typically taken by Brandy, these potential problems can, more frequently, be avoided. Furthermore, many of the more demanding, yet necessary, niceties of technique he recommends here, such as undermining the postauricular area and the region overlying the trapezius muscle, small "bites" with suturing and the aforementioned double-layered closure all become far less essential for the production of excellent scars. Despite these differences in technique and opinions, if one were to use strips as wide or wider than Dr Brandy does, I would strongly support the adoption of all of his recommendations.

WALTER UNGER, MD
Toronto, ON, Canada

References
1. Stough DB, Haber R. The donor site. In: Stough DB, Haber R, eds. Hair Replacement: Surgical and Medical. St. Louis: Mosby, 1996: 131-46.
2. Coiffman F. Use of square scalp graft for male pattern baldness. In: Unger WP, ed. Hair Transplantation, 1st ed. New York: Dekker, 1979:159-163.
3. Unger WP. Total excision techniques in donor area harvesting for hair transplanting. Am J Cosm Surg 1994;11:15-22.
4. Unger WP, Shapiro R. Hair Transplantation, 4th ed. New York: Dekker, 2003:in press.
5. Unger WP. The donor site. In: Unger WP, ed. Hair Transplantation, 3rd ed. New York: Dekker, 1995:183-214.