Technological Advances

For the past several years, a robotic modality for harvesting grafts has been available. This device (Artas; Restoration Robotics, Sunnyvale, CA) harvest grafts using a double-needle apparatus that is controlled through the use of a video camera system. Since the initial iteration, this device has been shown to harvest FU extraction (FUE) grafts very reliably. The newest software update is reported to permit harvesting at rates of more than 1500 grafts per hour with low transection rates. The system allows for the use of smaller needles, ranging in size from 0.8 mm to 1 mm and different needle designs to suit various situations. It may be that smaller needles could create smaller wounds in terms of eventual healing.

An improved lighting system enables the operating staff to more easily visualize the operative field and access the grafts for removal within the grids as the machine is functioning. The latest software allows the robot to assess the area to be harvested within a grid and with a single-button, one-touch system the device can ascertain the potential graft positions within the grid rather than having the operator manipulate the device to position it properly. The robotic head has undergone a design change that facilitates greater ease of movement of the device without having to shift the patient.

The algorithm for harvesting allows the operator to differentiate 1-hair, 2-hair, and 3-hair grafts and the ability to select these to harvest. In terms of making recipient sites, the new software permits the creation of recipient angles of 35° and is most helpful in making sites on the top/horizontal aspect of the scalp. It should be noted that this program may not be optimal in making sites at the lateral aspects of the scalp.

The robotic system has an integrated design feature that can allow the surgeon to draw out a hairline and the area to be transplanted. This design pattern can be transferred to the patient and followed by the robot in making recipient sites. Many physicians prefer to make the hairline sites themselves before considering using the site making mode. The author still prefers to make his own sites throughout the recipient area.

As with any approach to surgery, the robotic device is not perfect for all patients, and the surgeon must select patients who will benefit most from this approach. The author has found that patients with fine hair, thin skin, and very mobile skin can be less well suited for treatment with the robotic device.

Several new drills have been developed to which FUE punches can be attached. One drill in particular has been well received. The WAW (Devroye Instruments, Brussels, Belgium) uses an oscillating mechanism to facilitate the extraction of grafts. A foot pedal with 3 dials controls the initial speed of rotation, degree of oscillation, and speed of oscillation.

In addition, Dr Devroye has developed a punch that he refers to as a “trumpet punch.” This punch is constructed so that the inner bore of the punch is sloped and blunted to facilitate obtaining grafts and the external border is flat and sharp. The blunt internal border aids in avoiding transection.

It is advised that the surgeon use light pressure to allow the sharp edge to enter the epidermis initially and then allow for the oscillation to begin before venturing deeper into the tissue.

Other developments with punches include the hex punch from Dr Harris. The hex design acts to disrupt the tissue around the graft using vibratory action, which allows easier removal of the FU with less transection as compared with other punches.

A slotted punch developed by the author originally to facilitate visualization of hair angles and proper centering for FUE harvesting, has been adapted by Drs Park and Boaventura to allow for harvesting of long hair grafts.

The process of long hair harvesting allows the patient to avoid shaving large areas of donor. The slotted punch technique for long hair is quite tedious and there can be higher rates of transection.

Usually small areas in various parts of the donor area are shaved and the grafts are taken from these areas. This allows the patient to cover any evidence of the surgical process.

Implantation

Traditionally the primary approach to placing grafts has been the use of jeweler’s forceps to grasp the FU grafts and then place them into the recipient sites. To do this proficiently can involve substantial practice. Holding the grafts too tightly can lead to damage to the grafts and repeated attempts to place the grafts can also lead to damage. This may be a factor in some poor growth outcomes.

Increasingly, clinicians are adopting the use of implanters to aid in placing grafts. There are multiple implanters on the market, such as the Lion (Hans Biomed, Korea), OKT (Choi Instruments, Korea), and others, but the basic design is similar. A needlelike cylinder with a slit is attached to a spring-loaded stem that can push a graft into the skin after the implanter has been appropriately loaded. Sharp implanters are used to make the recipient site and place the grafts at the same time. Some surgeons are blunting the tips of the implanters and use the implanters after sites have been created. It is felt that the use of this type of implanter allows for less trauma during graft insertion. The technique uses premade sites that can be sagittal or coronal. Currently the surgeon must make or have someone else take a sharp implanter and make the tip dull. This is accomplished by using sandpaper such as 400 or 600 g weight paper and rubbing it over the edge of the needle of the implanter until it is sufficiently blunted.

Implanters come in various needle sizes to accommodate differing graft sizes. The surgeon must select the appropriate size to be used, and if there is difficulty placing the graft, repeated manipulation may damage the grafts. Many implanters are re-useable and can be taken apart, cleaned, and then sterilized for reuse.

An important aspect of the use of implanters is the work flow that must occur to perform implantation efficiently. In general, there must be at least 1 person loading the grafts, a second person handing the grafts to the surgeon to implant, and that person must then receive the unloaded implanter and pass it back to the loader. This system can take considerable time to develop. If the surgeon attempts to use 2 people implanting, this adds more complexity.

Bio-Enhancements

In an effort to improve graft survival, hair transplant surgeons are increasingly using bio-enhancements to decrease reperfusion injury and maintain energy for the cells of the grafts. The surgeon should be aware that the hair transplant grafts are without a blood supply for several days. The cells acquire nutrients via the process of inosculation. It can take 3 to 5 days for the graft to obtain a blood supply.

Some physicians are using more physiologic storage media such as Hypothermosol (Biolife, Seattle, WA). As grafts have no blood supply and are often stored out of the body for several hours, the tissue is subject to the effects of thermal damage, ischemia, reperfusion injury, and a lack of necessary nutrients, such as ATP, glucose, and oxygen. The normal balance between extracellular milieu and intracellular milieu can be adversely altered as the membrane ion pumps can be disrupted. Osmotic and oncotic imbalance can ensue, which is detrimental to cellular survival. Additionally, free radicals that would normally be eliminated with antioxidants may build up.

In an effort to respond to the metabolic needs of these grafts, a medium such as Hypothermosol can act to maintain ionic and osmotic balance, aid and support cellular metabolism, assist in the removal of free radicals, and ultimately decrease cellular death. This material storage medium has been shown to reduce apoptosis and diminish reperfusion injury. Hypothermosol is designed to be used at lower temperatures of 2 to 8°C, and in hair graft storage, lower temperature storage is used to decrease cellular energy requirements.

Studies on the use of hyperthermosol are limited, but they suggest an increase in graft survival and there are anecdotal reports of better graft growth and earlier growth.

Recently the use of liposomal-encased ATP as an addition to the storage medium and as an adjunct in postoperative healing sprays has been advocated.

A liposomal-encased ATP (Energy Delivery Solutions, Jeffersonville, IN) has been developed and this is the primary product in use. Again, studies are limited but there is a perception that this helps in graft survival. Studies in animals have shown that the addition of ATP can preserve limbs that have been amputated and reattached. As hair grafts are without supplemental oxygen while in holding solutions, the injury from ischemia could harm grafts and ultimately graft survival by protecting the ischemic cells. The use of ATP compensates for this period of lack of oxygenation by providing energy to the cells. The ATP also acts as a vasodilator, bringing in additional nutrients and decreasing reperfusion injury. The use of liposomal ATP also has been suggested as a postoperative spray, as it takes 4 to 5 days for a hair graft to be rebuild a vascular supply.

We use the combination of Hypothermosol and ATP in our practice as a holding solution. A common recipe for the use of Hypothermosol and ATP is 1 mL ATP to 100 mL Hypothermosol.

Adjuncts to Hair Transplant Surgery

Porcine Bladder Matrix

Acell is a bio material derived from porcine bladder. It is composed primarily of collagen, elastin, laminin, and fibronectin. There are growth factors inherent to the material but it is unclear as to whether these factors are active when the material is used. The material comes in sheets or in a powder.

Some physicians have used it for the linear scars of strip harvesting, as it is felt that the resultant scar is softer. It is being used for FUE wounds and it may aid in promoting the healing of the wounds as well as stimulating regrowth of new hairs. It is felt that it may stimulate the hair stem cell population and new hairs may arise in the FUE wounds.

Acell is also being combined with PRP in the hopes that the material will provide a scaffold for the PRP and aid in the slow distribution of growth factors from the PRP.

Lasers

Mester originally demonstrated that lasers can aid in wound healing and at a wavelength of 694 aided in hair growth in mice. Over the past decade, it has become evident that low-level lasers can provide a positive effect on human hair growth. The mechanism of action is believed to relate to upregulation of cyclic adenosine monophosphate and cyclic guanosine monophosphate. Various cytokines and proteins may be produced that can improve hair growth as well. The use of lasers allows hairs to enter into the anagen phase of hair growth and the hairs tend to stay in anagen longer. The efficacy of the low-level lasers is believed to be similar to that of minoxidil.

Numerous versions of the low-level laser therapy devices exist. Some devices are constructed as a hat, others are a comb or brush or a headband embedded with the light-emitting diodes. Larger units are often used postoperatively to aid in healing and perhaps encourage hair growth.

It remains unclear as to what is the optimal wavelength for hair loss treatment. Additionally, there is no well-developed protocol for usage for this indication thus far. Questions such as to how often the laser should be used, what power should be used, how long should a treatment be, and if there is an inhibitory effect that occurs with overuse, remain unanswered.

Currently, most devices are used a wavelength of 635 to 650 nm. Usage is recommended as 2 to 3 times weekly for 20 to 30 minutes.

Stem Cells

An especially intriguing area of hair transplantation is the use of stem cells. The public has been fascinated with the stories of numerous miraculous cures for many diseases with the use of pluripotent stem cells. Although the evidence for such miracle cures is often lacking, there is little doubt that the use of stem cells may provide major advances in treating many diseases and injuries in the future.

In terms of hair restoration, there is a lack of large-scale studies; nevertheless, the studies available indicate promise of hair growth based primarily on mouse and rat cell models. Studies on humans are few.

We are currently undertaking a study involving stem cells for hair growth. We have used adipose-derived stem cells to try to promote hair growth in patients with female pattern hair loss and male pattern hair loss. Our results thus far are encouraging. We have observed growth of hair but it is unclear as to how long the effects will persist.

Body Hair

Many patients who undergo hair restoration have marked hair loss and their donor area is insufficient to supply enough hair to cover both the frontal area and crown. For these patients, it may be reasonable to obtain hair from other locations, such as the beard area or other body areas to try to provide donor hair. Some patients may have areas of hair loss on their face or body where the use of body hair would be ideal for restoring the hair pattern in the area such as the beard area or eyebrows.

Body hairs also may be used to refine hair lines and conceal an unacceptable scar. Such grafts have been used in cases in which a scar from strip surgery needs to be improved.

The surgeon must be cognizant of the fact that body hair essentially retains the characteristics of body hair and does not grow like scalp hair. Also, the caliber and wave or curl of the hair may be different from that of the surrounding hair and the patient and physician should discuss how this may impact the aesthetic outcome of the procedure.

Strip surgery can be used to obtain beard hair by incising an ellipse in the area under the chin. This can heal particularly well and provide sufficient grafts for small cases, but most commonly the FUE/FIT (Follicular Isolation Technique) technique is used to obtain beard hair or body hair grafts.

Umar stressed that the surgeon should attempt to obtain hairs that are clearly in the anagen phase of growth. He suggests having patients use 5% minoxidil twice daily for 6 weeks to 6 months before surgery. At 7 to 10 days before surgery, he shaves the donor area to better identify the anagen hairs.

Patients need to be advised that body hair tends to have a lower survival than scalp hair, and many body FUs are single hairs. It is unclear as to why the rate of survival is less. Also, hypopigmented round scars will often be evident from the harvesting of body hairs. The skin in these areas will not generally tan when exposed to sunlight.

Scalp Micropigmentation

Many patients who undergo hair restoration have extensive hair loss. The donor area is limited and therefore it is unlikely that they can adequately transplant the entire area of hair loss. A possible solution to the situation is the use of scalp micropigmentation. Using scalp micropigmentation, the area can be tattooed to provide a sense of coverage. The technique works particularly well for patients that have some hair in the area.

Scalp micropigmentation (SMP) also can be used in patients with traumatic hair loss and scars. SMP has worked particularly well for the linear scars of strip harvesting. Some forms of hair loss from scarring alopecia are also well suited for SMP.

The SMP technique requires special inks and instrumentation. This is not a procedure to be done by the local tattoo artist. A high degree of proficiency is required for an optimal outcome. Needle depth is crucial and proper selection and deposition of the pigment is required to avoid blurring of color and making marks that are too large. If the color is placed too deep, there can be alteration in the apparent color of the pigmentation. This can be very disconcerting for the patient and physician.