Harvesting Techniques : FUT/Strip and FUE

Comparison between Strip Harvesting or FUT and FUE: A Fair and Balanced View [1]

AIM: To create the best possible outcome in hair transplantation using the limited number of donor follicles wisely; with no injury to the follicles and best artistic skills when placing them in the recipient area.

Ten years ago the use of the harvesting technique, follicular unit extraction (FUE) was advocated as an alternative to traditional strip harvesting of the donor tissue. Many physicians have tried the technique but with markedly varying success. A great deal of discussion by physicians, ancillary personnel, and the general public has occurred on the Internet and multiple media sources about the value of FUE versus strip harvesting and vice versa. Sadly, many of the claims of “superiority” of the newer technique are related to marketing and self-promotion rather than a clear scientific evaluation.

This article discusses advantages and disadvantages of both techniques to provide a more accurate and balanced view of the two approaches.

The Donor Area and Scar Formation

Strip harvesting produces a linear scar (Fig.1). The appearance of any donor scar can be a significant concern for patients who wish to wear their hair very short. The vast majority of patients who undergo strip harvesting have minimal scars that are easily concealed by the hair above the scar. In many instances the scar may not be evident at all. There are, however, some patients who have scars that have widened, often due to physical activity.

To avoid multiple scars many physicians who use strip harvesting employ a single scar technique even if multiple procedures are performed. Utilizing careful dissection along the incision line, damage to hair follicles can be diminished.

The use of the trichophytic method of closure for strip harvesting can also be extremely helpful in improving the appearance of the strip harvest scar. This allows hair to camouflage the scar and the hair growing through the scar can limit the stretching. Avoiding damage to the hair follicles along the incision lines is crucial in preventing the appearance of a prominent scar.

Using a layered closure and undermining minimizes scars

There are patients such as those with Ehlers Danlos syndrome, who because of alterations in collagen deposition, are prone to widened scars and poor wound healing. There is little that can be done to prevent such scars in these patients. The circular scars produced by FUE may suffer the same fate and be stretched in these patients.

The primary rationale for the use of FUE is that a linear scar is avoided. Several proponents of FUE market the procedure as a technique that does not involve cutting, is less invasive and does not result in scars (i.e. “scarless”) While a linear scar is not created with FUE, circular scars are created. The length of incision is greater with FUE than with strip harvesting. This is apparent when one calculates the circumference of a 1mm punch (1mm x pi = 3.14) and then multiplies this by the number of grafts, for instance, 1000 grafts (1000×3.14 =3140mm which equals 31.4 cm). In comparison, a strip harvest of 1000 grafts assuming an average density of 80 FUs per sq cm and a 1cm strip width the length of the scar created would be 12.5cm (1000/80 = 12.5).

“Cutting” is clearly involved when using a punch. Although a linear scar is not produced with FUE, scars are created and evidenced by virtue of the fact that hypopigmented or hyperpigmented “dots” may be visible.

When using FUE it is important to recognize that as more and more grafts are harvested the area may appear moth eaten(Fig.2). This is opposed to the strip technique where hair of similar density is brought back together at the suture line. Opponents of strip harvesting would note that if hair does not grow well in a strip scar and the scar widens, then the scar might be apparent if the hair above it is short or otherwise thin.

Some promoters of FUE have stated that nerves and veins are not cut. This claim is untrue. By entering the skin with the punch arteries, veins and nerves are cut. It is important to point out that with FUE the patient’s hair usually must be trimmed quite short for harvesting. This is the case especially when large numbers of grafts are required.

Graft Survival

There is some concern that because the FUE grafts may have very little tissue surrounding them that they are less likely to survive. Such grafts are more prone to dehydration, which has been shown to be a major cause of diminished graft survival. The lack of perifollicular tissue is often a result of “pulling” on the graft to remove it. Because there is added manipulation in trying to remove a graft this may also contribute to diminished survival (Fig.4). Sometimes the ends of the bulbs are splayed or unusually far apart. This makes the bulbs more susceptible to trauma, as a result of increased graft manipulation during implantation. Clearly there are patients who have undergone the FUE procedure and have excellent results. Some physicians might argue that less successful results may be due to technical surgical skill rather than the nature of the more fragile graft created with FUE.

With FUE there is a greater chance of transection of hairs as compared with strip harvesting and this results in poor growth or lack of growth depending on the level of transection. The rates of transection seem to vary widely with FUE.

Drs Limmer, Kim, Martinick & Mayer have done numerous studies showing transected hairs have 9-18% chance of survival. Conversely, with strip harvesting, grafts may be damaged in making the initial skin incisions and subsequent dissection of the tissue, but this is minimal. The use of the microscope for dissection of the donor strip should limit transection rates to 1-2%. Grafts created with strip harvesting generally have a greater amount of surrounding tissue and fat. (Fig.3)

This may decrease the chance of dehydration and allow for greater leeway in manipulation of the grafts during placing and hence, better graft survival.

Placing of Grafts

When manual placement of grafts is utilized there is no difference in regard to the technique of placement of strip harvested or FUE harvested grafts. There may be significant concern about the fragility of the FUE grafts and the fact that they may be more susceptible to drying and over manipulation.

Technical Expertise

The primary concern with FUE is the rate of transection. The reports from physicians performing FUE indicate that the rate of transection is higher than with strip harvesting.Patients with curly or very wavy hair may be difficult to treat when FUE is used. In comparison, strip harvesting is suitable for all types of hair

FUE can be a tedious process and both patient and physician may experience fatigue. This can limit the amount of grafts that can be harvested in a single session. Because of the time usually involved in harvesting and the possible strain on the surgeon performing the harvesting one has to wonder if less emphasis is placed on the recipient area. Poor outcomes in FUE are more commonly reported with FUE (Fig.5)

The learning curve for FUE can be slow for physicians who are used to excisions with scalpels and unaccustomed to the use of punches for harvesting.

 

ISHRS Position Statement on Qualifications for Scalp Surgery [2]

The position of the International Society of Hair Restoration Surgery is that any procedure that involves tissue removal from the scalp or body, by any means, must be performed by a licensed physician in the field of medicine.  Physicians who perform hair restoration surgery must possess the education, training, and current competency in the field of hair restoration surgery.  It is beyond the scope of practice for non-licensed personnel to perform surgery.  Surgical removal of tissue by non-licensed medical personnel may be considered practicing medicine without a license by state, federal or local governing boards of medicine.  The Society supports the scope of practice of medicine as defined by a physician’s state, country or local legally governing board of medicine.

Number of grafts per session

In general most physicians who perform FUE are not able to do as many grafts in a single session as can be done with strip harvesting. With strip harvesting, sessions of 2000-3000 grafts are very common and some physicians frequently perform sessions in excess of 4000 grafts. There are, however, exceptions and some physicians, routinely performing motorized FUE, report similar in excess of 2000 grafts. Unfortunately, the rates of graft transection in these larger FUE sessions has not been studied or reported.

Cost

The cost of FUE is usually significantly more than that for strip harvesting on a per graft basis. The costs may exceed double the price of strip harvesting.

FUE into scars

FUE can be used to try to camouflage linear donor scars. This is considered by many hair restoration surgeons to be another excellent use of the technique. Some surgeons have suggested that a combination of strip harvesting and FUE is the optimal use of the techniques.

Increased donor supply

Advocates of FUE have stated that FUE expands the donor area in the scalp. With FUE the surgeon can harvest in the nape of the neck more easily as well as the areas superior and more anterior to the ear. This apparent advantage is somewhat negated because the area can become moth eaten in appearance as more and more graft are obtained. In addition going into the nape of neck area or high onto the scalp can be a problem later in life for the patient as some men lose hair in this area as a result of male pattern hair loss.

Complications

Telogen effluvium can occur in the donor area with FUE or strip harvesting, but this is uncommon. Infection is a very rare complication with hair restoration surgery. Dehiscence with strip harvesting can occur but this is quite rare and would be associated with a surgical error. Similarly, necrosis of tissue should not occur unless the area harvested is too wide and/or closed under excessive tension. This could also occur if the arterial supply was already compromised.

Patients may complain of altered sensation but this can occur with strip harvesting or FUE as small nerves are cut in both procedures. Years ago some strip-harvested patients may have experienced significant dysesthesia as a result of damaging the occipital nerves. As dissection should be at the level of the fat or perhaps at the level of the fascia these nerves should not be damaged. Bleeding occurs with both techniques.

A complication that is specific to FUE harvesting is the burying of grafts. This happens when the punch pushes the graft into the subcutaneous tissue. The grafts can be difficult to recover and can lead to a foreign body reaction and cyst formation.

Hypertrophic scars and keloids should also be rare with FUE or strip harvesting. If patients have a predilection for keloids making punch excision will not limit such scar formation. In general hair must be cut short to be harvested with FUE.

Staffing

Strip harvesting requires a larger staff than FUE. For FUE the surgeon can get by with just one or two assistants but if the surgeon has to alter course and use a strip harvest having only one or two assistants could be problematic.

Up to 4500 FUG can be done in our clinic in one day because of the excellent training of our technicians and doctors. Most clinics can only do 2000 per day using FUT and less with FUE. (Fig.6)

Summary

Each technique has advantages and disadvantages. On a cost-benefit ratio strip harvesting provides the most cost effective procedure.

FUE may be the ideal choice for harvesting trunk, leg and arm hair, and it is an excellent way to camouflage strip scars.

A single course or training session on one aspect of the hair restoration procedure such as harvesting is inadequate training for a physician to learn how to perform hair restoration procedures. The surgeon must acquire a sense of the aesthetic and technical components of the procedure.

Finally, the incision of skin and tissue, whether using instruments that create a linear or circular incision, is considered surgery and should only be performed by the physician.

Reference:

[1] http://www.ishrs.org/article/comparison-between-strip-harvesting-and-follicular-unit-extraction-fair-and-balanced-view

[2] http://www.ishrs.org/in/position-statement-qualifications-hair-specialist-doctors