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The temporo-parieto-occipital flap, introduced in 1969, was the first large monopedicled flap performed in the scalp for reconstructive and aesthetic purposes. Its versatility for correction of many areas of the scalp relies on its wide arch of rotation, based in the flap's pedicle, which is the superficial temporal artery and vein. The axial pattern of the flap is explained by the unique kind of vascularization present in the scalp, based on a profuse intraparietal blood flow with multiple anastomoses. This is confirmed by careful anatomic studies. In 1979, the free version of the flap was first accomplished. This flap allows for an excellent source of reconstruction of the anterior hairline as it provides hair growing in the appropriate direction. In this article we provide for precise and accurate information to successfully perform this flaps. We strongly believe this flap has very specific indications for which no other method can achieve the same result.
When we first began using the temporo-parieto-occipital (TPO) flap in 1969,1,2 we challenged several principles that were considered rules, all based on lack of confidence in the vascularization of the scalp. This was why bipedicled flaps were widely used at that time, which required large skin grafts for closure of donor sites, with very poor aesthetic results. Other flaps commonly used were much shorter and never crossed the midline, because vascularization was considered to be substantially diminished at this point. After a deep study of the vascularization of the scalp, based on cadaveric dissections, we realized that all these principles were not true. We designed a flap with dimensions that seemed challenging at that time but that are perfectly understood nowadays. Most surgeons looked with skepticism this kind of design, until clinical experience confirmed its liability. The success of this flap relies on two factors: whether it is an axial flap and the sagittal orientation of the flap.
The flap is based in the temporal artery and its anastomotic arch with the retroauricular and occipital artery. This arch is anatomically consistent (Fig. 1) and provides for a good blood supply from base to tip. When we first began using this flap, we made two delays 7 weeks apart. In the first one the flap borders were incised; in the second, the tip was raised and reapplied. We did this to ensure vitality of the flap because of the torsion of the pedicle that occurs at its base at the time of transfer. But when we began using the TPO flap in its free version, in 1979,3 we verified profuse bleeding from base to tip. So now, instead of delaying the flap, 7 days before transfer we raise it completely from its bed and reapply it. With this maneuver we ensure vitality of the tip at the time of the transfer. Also, relying on the profuse intraparietal blood flow, we began making special designs such as diagonal flaps and encircling monopedicled flaps,4 crossing the midline without difficulties, despite the current beliefs of that moment.
We changed the vertical or transverse orientation of the flaps used until then into a sagittal orientation. This allowed for primary closure of the donor site, instead of relying on skin grafts for this purpose. Throughout the years, we have been so satisfied with this flap, in its conventional and free versions, that, with slight modifications, we continue to use it widely nowadays. These modifications consist of reapplication of the flap, as previously mentioned, a modification in flap design to fit exactly in the anterior hairline when used for this purpose, and a modification at the base of the pedicle.
To obtain a more natural result, we modified slightly the design of the flap to adapt to the desired contour of the anterior hairline (Fig. 2, left). The dimensions of the flap are 4 to 5 cm in width, depending on the compliance of the donor site, and 24 to 26 cm in length. If necessary, the midline can be safely crossed. The length of the flap is obtained by measuring the distance between the base of the flap and the distal part of the alopecic area (Fig. 2, right).
One week before transfer, the flap is carefully marked as previously described. Lidocaine 1% with adrenaline 1:100.000 is infiltrated in the border of the flap to provide for local anesthesia and to minimize bleeding. The flap is raised entirely from its base in a subgaleal plane to preserve the arterial network and is reapplied on-site. The borders of the flap are sutured with 5–0 nylon. This can be performed in the office as an outpatient procedure.
The flap is elevated in a subgaleal plane. Suture of the donor site is accomplished by a wide dissection of the retroauricular region reaching the neck. We take advantage of the elasticity of the neck to obtain closure with no tension (Fig. 3). We close the subgaleal plane with 3–0 vicryl, and the skin with 5–0 nylon, avoiding hair bulbs. This maneuver minimizes hair loss in the suture line.
If closure of the donor site cannot be accomplished without tension, we resort to a very interesting maneuver to solve this problem. We transform the large neck advancement flap into two flaps, a bipedicle and an advancement flap (Fig. 4). In this way, the different vectors of the flaps allow for a more effective distribution of the remaining tissue, which results in closure without tension.
After suture of the donor site, an incision is made in the anterior hairline. The anterior border of the flap is carefully sutured in place with half buried 5–0 nylon, avoiding hair bulbs, with previous de-epithelialization of 2 mm to allow for hair growth anterior to the scar. After this is accomplished, the alopecic area is resected and the posterior border of the flap is sutured (Fig. 5). To avoid dog-ears in the base of the flap, the surrounding frontotemporal area is widely dissected. This dissection must be subcutaneous in order not to damage the temporoparietal fascia, where the blood supply enters the flap. The curved border of the anterior hairline is sutured to the curved border of the flap results in a raised suture. After a few days, this area settles down and this defect disappears.
A slight modification in design at the base of the flap is accomplished to gain access for dissection of the superficial temporal artery and vein (Fig. 6, left). Tissue requirements are properly addressed in the alopecic area, determining the length of the flap.
The superficial temporal artery and vein are identified in the contralateral preauricular area (Fig. 6, right). This flap is ideal for microsurgical anastomosis as it is performed between vessels of equal caliber.
First, the pedicle of the flap is identified (Fig. 7, top) and isolated from the surrounding tissues. Collateral vessels are ligated. Then, the flap is raised in the subgaleal plane and the donor site is sutured carefully (Fig. 7, bottom).
The pedicle is clamped and sectioned and the flap is ready to be transposed to the contralateral side (Fig. 8).
The flap is secured in place with a few stitches and the anastomosis is performed. The clamps are released and bleeding is confirmed. After this step is accomplished, the alopecic area is removed and the flap is sutured in place with 5–0 nylon (Fig. 9).
While performing this kind of flap, well-executed technique is essential for diminishing the incidence of complications. Throughout this text we give important tips about how to perform this flap and how to avoid complications. Problems in the donor site are, by far, the most common complication of performing this flap. Tension in the suture is the responsible. In this case, the surgeon has to wait for granulation and, if necessary, perform a skin graft when the wound is clean. After a period of 6 months, an advancement flap, with or without a bipedicle flap as previously described, can allow for removal of the skin graft. Regarding flap necrosis of the conventional flap, surgeons who start doing this procedure can perform the two delay procedures until they gain confidence with the procedure and can resort to Doppler to trace the pedicle. Subcutaneous dissection around the base of the flap diminishes the dog-ear at this level as well as pedicle torsion. It is important to perform flap dissection very carefully, with total preservation of the galea within the flap where the blood vessels flow, and to treat the flap gently, avoiding rough maneuvers. Taking these precautions and with skill and experience, total flap necrosis does not occur, and we can expect partial necrosis in 4% of the patients. When this occurs at the hairline, the surgeon can still resort to the contralateral side to cover the defect with another TPO flap or can perform the free version of the flap. As we previously mentioned, the free flap has many advantages over the conventional flap in certain circumstances. But, regarding necrosis we have to take into account that when it occurs, it compromises the whole flap. The incidence of this complication in our series is 5%.
Traumatic alopecia is a very disfiguring entity. It is due mainly to burns occurring in infancy and scalp avulsions. In very large alopecic areas, where 70% of the scalp is compromised, previous accomplishment in tissue expansion of any flap is mandatory. We strongly believe that hair follicle transplants in skin grafts or scar red tissue accomplish very poor results. For this reason in these cases we use scalp flaps; there are many publications on the subject.5,6,7,8,9 The versatility of the TPO flap makes it useful for reconstruction of wide alopecic areas of the fontotemporal, sideburns, and parietal regions, due to its wide arch of rotation. In many cases, the free version of the TPO flap is used with excellent results (Fig. 10).
Despite the widely accepted method of follicular transplant because of it simplicity, when offered the two methods (flaps and grafts) to our patients, explaining benefits and drawbacks with pictures, the majority of them choose flaps as their surgical procedure.10,11,12,13,14,15,16 Patients who want only subtle changes and are not willing to go through a more complex procedure choose micrografts. We also use the TPO flap in many patients who are dissatisfied with micrografts, for example, due to not obtaining the hair density they desire, or in patients with severe scarring from previous micrograft procedures.
But not all patients are good candidates for the TPO flap. There are two anatomic features that the patients must have to perform a successful TPO flap: an elastic scalp and a high parietal implantation.
To achieve closure without tension in the donor site, the patient must have an elastic scalp. This is easily confirmed during the examination, by sliding the scalp and with pinch maneuvers. If the scalp is rigid, the patient is prone to complications in the donor site due to tension in closure.
The superior border of the flap should be inferior to the parietal hair-bearing margin. For design purposes, to perform this flap the patient needs to have a wide fringe of hair at this level. In young individuals, the surgeon should anticipate future hair loss and lower the superior margin to areas judged to be permanently hair-bearing. We perform a complete surgical plan for each patient, taking into account the degree of baldness, according to our classification (Fig. 11). For grade I, we perform one TPO flap. We have the option to choose between the conventional TPO flap and the free version of the flap. This can be used only in grade I baldness because it uses both temporal pedicles. For curly hair, the conventional flap offers the same result as the free flap because in these cases hair conceals the scar nicely (Fig. 12). But for straight hair, the free flap is the first choice because of the natural (forward) direction of hair growth achieved with this method (Fig. 13). For grade II, two flaps are planned, one from each side of the head, within an interval of 1 or 2 months (Fig. 14). If the bald region is large, 2 cm of alopecic scalp is left between the flaps. This narrow strip can be safely resected a few months later. For grade III, if the donor site allows for it, we add a third flap, taken from below the first flap, 2 to 3 months after the last operation (Fig. 15). The major drawback attributed to the conventional flap is the notorious scar at the frontal hairline that can be seen in some patients, due to the backward direction of hair growth. This can be successfully disguised by making irregularly distributed follicle unit transplants anterior to the scar. We strongly believe that despite the actual popularity of follicular transplant, which does not require as much skill and ability as demanded for this kind of flap, this kind of procedure is certainly the only acceptable method in certain cases, such as burn or traumatic alopecia and, with no doubt, the method of choice for patients who demand complete restoration of hair density to their prealopecic state.