Doubts, queries, articles

Talking about transplants

Transplants: How do they work?

Nowadays a hair transplant consists of transplanting hairs from the donor zone where they don’t fall out to the receptor zone where there is little or no hair. That is to say that it is a redistribution of a patients existing hair. And it is possible thanks to the fact that not all the scalp is influenced in the same way by the masculine hormones.
We all know that even
in very bald men there is still a ring of hair extending around the sides and back of the head.
If this hair is not lost during the development of baldness, then it is because these follicles don’t have receptors for DHT, the hormone which causes the frontal and parietal hair to weaken and cease to grow.
a hair transplant surgery follicles are obtained from donor areas at sides and back of the head and are later reinserted into the bald or thinning areas of the scalp.
Since these follicles are unaffected by the hormone DHT, they continue to grow even though they have been transplanted. That is to say that this hair will grow throughout the patient’s life as it would have done if left in its original position.
That said,
what a hair transplant cannot avoid (and this is an important factor to bear in mind when designing the pattern for newly transplanted hair) is that hair continues to be lost in areas susceptible to hair loss.
and to avoid as much as possible the development of the alopecia, it’s advisable to continue using medicinal anti-DHT measures (finasteride, minoxidil). 
In this way we can avoid or at least slow down the need to perform successive transplants in the future due to a new reduction in density.
it is almost impossible to have the same density as was there before the onset of hair loss, when we were adolescents,
and it is because of this that in many occasions the appearance of a natural design and adequate hair density corresponding to the patients age depends on the skill of the surgeon.

Who are the most suitable candidates?

Hair transplant representatives and sales personnel will make you believe that you are a great candidate for a transplant, that you have an excellent donor zone, that you will achieve a natural result and that your head will be as densely populated with hair as it was in your youth. Don’t trust them; everybody needs to be evaluated individually by the surgeon or surgeons who are going to perform the transplant.
First of all, a transplant should always be considered as the ultimate phase in medical treatment.
A hair transplant does not cure alopecia; it only attempts to repair those areas which have been irreversibly affected by the androgens. Therefore, surgery is not preventative but reparative.
A transplant is only a transitory patch if the natural history of the patient’s hair loss is not taken into account.
There are some basic criteria which act as a guide for us in deciding if a hair transplant would be helpful or not.
 Younger patients (less than 30 years) are generally not suitable candidates as their hair loss has not yet gone to completion, meaning that it has NOT YET STABALISED. 
To perform a hair transplant too early and without determining the level of stability can lead to a poor distribution of the transplanted hair given that the surgeon cannot know exactly how much native hair is going to be lost. What could be a great result now may not be in the future, since transplanted hair never falls out. Those who have unstable alopecia, (whatever the age is, but mainly in younger patients) are primarily candidates for medical treatment (Finasteride +/- Minoxidil).
In 80% of cases, age related stability is achieved around 40 – 45 years.
Sex: The pattern of baldness is different in men and women.
Receptor area:
In men the areas with alopecia are more local
and the extension, miniaturization and total disappearance of hair is more frequent. In women the distribution of hair loss is more spread out and extends over the entire head and the alopecia is seen as thinning and not as complete loss of the hair in any specific areas.
Donor area: 
In men the donor area tends to be more extensive,
mainly in the temporal-occipital areas. In women the temporal area is also affected by the androgens, meaning that the lower occipital is the only area which can be used for both sexes.
In both cases the ideal indicator that a transplant is feasible is the hairs stability, so that a long lasting result can be guaranteed.
Extension of hair loss: Obviously the greater the area affected then the less donor area is available and thus results will be limited. A patient who is worried about their hair loss and with incipient alopecia, if quickly controlled with medication then with a normal donor zone a complete repair with good density in the receptor zone can be achieved. A patient with advanced alopecia can hope to achieve partial cover and/or moderate densities in the area with a good donor zone area. The stability also lets us be more ambitious in density in the affected area as we are not expecting any significant progression of the alopecia.
Density of the donor area: Hair density is defined as the number of follicular units which exist per square centimetres. The greater the density of the donor area then the more follicular units can be transplanted. Patients with density of less than 60 follicular units per cm2 are poor candidates.
Multiple follicular units (MFU): Or family of follicular units; this is a characteristic which some patients have and which greatly increases the extraction capacity of units in the donor zone. This is a point where there are various units close together in a reduced space (for example, units of 2+1, 2+2, 3+1, 2+1+1 etc..). This allows us to extract one of the units, leaving the others behind to occupy the space and thus avoid “white dots” (white gaps or points) in the donor zone.
Number of hairs per follicular unit: In the donor zone we find units of 1 – 4 hairs. In the end the coverage achieved is directly related to the number of hairs inserted. And it’s clear that inserting 1000 units of 2 hairs is not the same as inserting 1000 units of 3 hairs. The higher the number of units that have more hairs then the better will be the result. In a transplant of the front hair line, we need units of only 1 hair (singles) to produce a natural looking hair line. Behind the front line we use units of 2 hairs and then units of 3 hairs. In the crown it isn’t necessary to use units of 1 hair, but we do need many units of 3 hairs to guarantee coverage in an area where the hair is distributed in a centrifugal pattern emanating from a central cowlick.
Therefore, and depending on the area to be covered, our needs can also vary.
The objective is to always be between 2.0 and 2.5 hairs per follicular unit. If the patient doesn’t possess the desired units and the range is less than 2.0 hairs per unit, then obtaining good coverage is difficult.
Type of hair: This factor is of equal or greater importance than the density of the donor zone. The texture (thickness), colour and structure (straight/curly) are important factors to evaluate before a transplant and because of these the number of units required in the same zone is different for each patient.
Texture: The normal thickness of hair is between 50 and 60 microns. A hair of 70 microns is very thick while a hair of 40 microns barely provides coverage. We have to consider a follicular unit as consisting of various hairs, therefore we duplicate or triplicate the thickness at the point of insertion of the unit (that is to say, 3 hairs of 70 microns thick is equivalent to 210 microns; 3 hairs of 40 microns is equivalent to 120 microns). And even though measured in microns, this is still a large difference. Therefore a thick hair is more desirable than a fine hair for creating greater coverage.
Hair colour: This is another point which can be good or bad. It is known that the effect of greater coverage is achieved when the colour of the hair more closely matches the colour of the scalp. For someone with very dark hair and a white scalp, any kind of hair loss is very quickly noticeable. Having light brown, blonde or grey hair is an advantage in this respect. Finally, hair which has two colours (those that have white and black hair or artificially using highlights) offers a greater effect of coverage.
Structures: Obviously a curly hair will give greater sensation of coverage than a straight hair as it has more spatial volume. The only thing against curly hair (which is also curly beneath the skin) is that it is technically more difficult to extract than straight hair.
Race: Asians have very straight hair and usually have less density than Caucasians, so there is need to have experience with this kind of hair. Dark skinned persons tend to have very dark curly hair, and since the skin is the same colour then very little contrast is offered and so the appearance is much better. On the negative side, their scars tend to form keloids and so there is more possibility of the scar being noticeable with the strip technique. The hair density in these patients is also less than in Caucasians who have a wide range of hair and skin.
Skin laxness: This is important only when evaluating for the strip technique (unnecessary for FUE). The donor zone´s laxity needs to be tested before operating to calculate the area to be extracted and avoid problems when closing the wound (traction = complications vs. a wide scar). Those that have poor elasticity in the occipital zone could be candidates for individual extraction of follicles (FUE). The elasticity can be increased through exercises performed on the skin of the donor zone.

How to get the best results

What’s the difference between a good transplant and a disastrous one?
There are many factors but the most important one are the surgeon’s skill, whether or not the patient makes a good hair transplant candidate and most importantly the technique employed. A surgeon may be very talented and you the perfect candidate, but the results will not look natural without the correct technique.
Lamentably the history of transplants began with the old punch techniques (or doll´s hair grafts) which in spite of being technically inacceptable due to the unnatural results, they persisted for long enough
and gave hair transplants a  bad name. Fortunately technical advances prevailed and mini and micro implants appeared which achieved a frontal hair line that was more natural looking, although not perfect. The reason is simple, if you want something to appear natural, then you have to imitate nature herself as therein lies the perfection
Hair in its natural form grows in what we know as follicular units (F.U.´s). Regardless that this concept was known to pathologists for quite some time, the existence of F.U.´s was largely forgotten about by hair restorations specialists. The adult follicular unit consists of 1 to 4 terminal (thick) hairs. But apart from these terminal hairs, the F.U. also contains 1 or 2 fine hairs (down hairs), sebaceous glands, small muscles and thin nervous and vascular systems, surrounded by a thin band of collagen called the perifolliculum. The follicular unit is the basic hair structure and should be conserved and transplanted with complete indemnity so to achieve the most natural appearance and maximum growth.
During a hair transplant session using the strip technique, the follicular units should be separated by expert assistants using binocular microscopes to assure the complete integrity of the units before being transplanted. In a session performed by follicular unit extraction (FUE), the follicles are extracted individually although it is also customary to view them under the microscope to check their integrity and cut away those parts which are of no use to the unit (cutaneous tissue).
Once the follicular units are ready for insertion, regardless of the method used for their extraction, we now need to implant them into the bald or thinning areas whilst causing the minimum trauma possible to the hair follicle and receptor skin. 
For years this was done using the classic system whereby the surgeon placed the implants one by one into the incisions previously made by a small scalpel. The implants placed in this way had a tendency to come out; therefore it was habitual that they were placed between 4 and 5 mm away from each other.
Implants were then inserted into other areas to give time (around 20 min) for the fibrinogen to convert into fibrin which holds the implants in place before returning to work on the areas where spaces were left.
From here on out the distance is now from 2 to 2.5 mm. In expert hands the same process is repeated various times until the implants are as close as possible, usually around 1 to 2 mm apart. Others prefer to perform a second session at a later stage. This entire process has also evolved. Laser was first used a decade ago to make smaller incisions with less bleeding. The use of LASER in hair growth treatment is a topic under a lot of debate. Many hair surgeons believe that laser is only a marketing tool. This worry came to light in the ISHRS Annual Congress in 1995.
LASER converts electrical energy into light, and what it creates in the scalp are incisions or holes which burn and damage the surrounding area. The incisions are caused by tissue vaporizing which damages the transplant area and affects the future growth of the transplanted follicle. Current lasers are less damaging but still cause excessive thermal damage to the tissue (burning). It is our opinion that this technique should NEVER be used.
We believe that currently the best method of placing follicular units in the receptor area is by using the Implanter. With it, the hair enters the skin protected by the metallic sheath of the channeled needle (which can measure 0.7, 0.8, 1mm) and is deposited at the correct depth and angle in a natural fashion, 
without the pressure or damage that forceps can cause. The implanter preserves the vitality and integrity of the FU and as a consequence results in a better survival rate (greater than 93%), better growth and better development (less folliculitis and less scabbing). Moreover, by creating a smaller incision, the FU´s can be placed closer together right in the beginning of the session without worrying about them falling out, especially in those areas where greater density and naturalness are required, in the front hair line for example, where a distance of 1 mm between implants is needed.
Finally the surgical scars on the scalp heal quicker, the scab produced is minimal and since the incisions are smaller, the skin recovers its natural state without leaving any signs of perifolicular sinking which so often appears from other wounds or larger implants.
Is a follicular unit transplant the same as a transplant done with mini or microimplanters?
No, definitely not.
In a follicular unit transplant, the size of the implants is what determines the overall naturalness, meaning the actual size of each follicular unit individually. In the mini or micro implants the size of the implant is determined in an arbitrary fashion by the assistants as they cut the donor tissue as instructed by the surgeon.
In mini and micro implants, the conservation and indemnity of the follicular units is not valued. The determining factors are based on the time in surgery and economic considerations. The assistants use a scalpel to quickly produce the strips which are then separated into fine implants using direct visualization (usually with a microscope). Therefore, the resulting implants are generally bigger and contain more follicular units and therefore a greater number of hairs in each implant. A donor area is also required.
The greatest advantage of follicular unit transplants (apart from preserving the units to gain efficiency and growth) is the ability to be able to transplant into small receptor zones (crown, corners of the forehead or scars). The resulting implants are small not only because the follicular unit is small itself but because the excess surrounding tissue is removed under the microscope. This is how they can be inserted into very small incisions the same size as the needle in the receptor zones and heal in a few days without leaving any kind of mark.
When a transplant is carried out by an expert surgical team, the transplant of follicular units gives a completely natural result, better takes advantage of the donor area and provides the best cosmetic result in over one or several sessions. The transplant of FU´s requires a lot more time to separate the follicles and also requires a very well trained team. Be very careful because if you are looking for a cheap implant you may opt for a micro implant and not a transplant of follicular units.

How many hairs do I need?

How many hairs do I need?
This is one of the most frequently asked questions by possible hair transplant candidates. To answer this question we must take into consideration several aspects:
Be realistic in the work that can be carried out: And transmit this to the patient as it is the surgeons job to know, based on experience, what will the patients future appearance be like.
For example, a person who is extremely bald (Norwood 6 or 7) and with fine hair will never hope to have a transplant with any level of density. 
If these facts are not made known to the patient beforehand then dissatisfaction afterwards will be unavoidable. When someone has lost 65 – 75% of their hair (the normal loss for Norwood 6 or 7 patients), a part of the bald area could be covered with a good enough pattern which would surely improve the patient’s appearance. If we were to try to achieve the original density, there would not be enough hair in the donor area to complete the process.
Evaluate the hair-loss
The donor area and the characteristics of the hair, 
Working with realistic expectations, the total number of implants which are required for each patient will depend on the contrast in colour between the hair and the scalp, the density of the donor area, the laxity of the scalp,
the number of hairs per follicular unit and the type of hair (colour, texture, thickness…etc). The surgeon considers these factors and combines them with the patients’ expectations and calculates the amount of work required. Still though, at time it is very hard to know if the patient will be satisfied.
Bear in mind the patients age and the possible evolution of alopecia after the operation: this has already been discussed.
Consider if one transplant alone is sufficient or if we need to plan several consecutive sessions. The FUE technique is usually carried out over several days as the extracting of the F.U.´s is slower than other methods.
And finally to bear in mind the total mid- to long-term costs for the patient.
Medical incompetence is more common than is actually recognized. The error of the professional who offers unrealistic expectations always leads to a dissatisfied patient. And this can only be avoided with very clear explanations of the entire procedure and with particular emphasis on determining the results which the patient can hope to receive.
A man who is used to his baldness will be easier to keep happy and will accept a less than complete result as opposed to a younger man who is beginning to lose his hair 
and still remembers the days when he looked in the mirror at a full and gleaming head of hair. The younger patient will always want a front hairline similar to his youth and will be unhappy with anything less. Given that the surgery is permanent, the surgeon should consider carefully a hair pattern that is appropriate for rest of the patient’s life. The surgeon should also bear in mind the hair remaining the in the donor zone. It is due to these reasons that we consider some younger patients to be unsuitable candidates for a hair transplant.
A mature patient with considerable hair-loss will be much happier than before with a restored frontal hairline and a modest amount of hair covering his head for the first time in years.
That said, the great majority of patients that we consult lie between these two extremes and it is here that the professional must carefully instruct and educate the patient so that he understands the goals we can achieve and the efficiency of the process.If we take into account human psychology, the dynamics of hair and practical experience, it is not always wise to recommend a specific number of implants as if this were a definitive and absolute amount. The amount is orientative and if possible above what is reasonable and safe to carry out. It should also always be decided based on the five guidelines mentioned above.
The goal of the hair transplant professional is to help the patient understand how close he can get to resolving his needs and personal expectations,
how much the entire process will cost and how many sessions he may need. With the right approach, patient satisfaction is easy to achieve.
It is important to bear in mind that the number of hairs to be transplanted reflects an estimated amount of the total hair that can be transplanted and is applicable to each alopecia sufferer individually. The amount of hair that can be transplanted depends on the five guidelines above and the experience and skill of the surgeon.
The impact of a transplant depends on the area being transplanted and the number of implants used. However, it is still useful that the patient has at least some idea of the number required in the initial and subsequent procedures.

Choosing the right surgeon

Choosing the right surgeon

Many doctors have attempted to access the lucrative market of the hair transplant industry due to its rapid growth in recent years. Unbelievably, a paediatrician can become a hair transplant surgeon by completing a one weekend long course without the need of any kind of certification. Before making a decision to submit to a procedure be sure that it is the specialist surgeon who answers your questions and not a representative.  But there are also many qualified surgeons who are recognized internationally. Our advice at injertocapilar.com is that once you decide to undergo hair transplant surgery, then investigate and study in depth the available techniques, different clinics and surgeons.

It is important to speak with or see the results of a patient who has had a transplant at the same clinic.

Our medical group injertocapilar.com, on deciding to operate only by the FUE technique, strives to achieve results by investigation, quality and adopting the most advanced techniques.

Talking about transplants

The development of hair transplant surgery

The hair autotransplant (initially skin with hair) was performed with varying degrees of success in the first years of the 19th century.

The first person to demonstrate the possibility of transplanting hairy areas in animals was Dr. Baromio, around 1804, but the first to treat hair loss by hair autotransplant was Dr. Unger in 1822. Dieffenbach published his doctoral thesis in 1822 also and in it described autotransplants of hair in animals.

The modern development of hair transplants did not occur until the last century. In 1939 a Japanese dermatologist called Shoji Okuda was the first to describe the punch technique by using a circular scalpel for grafts in patients with bad burn injuries.

Dr. Okuda transplanted grafts of skin with hair and introduced them into small apertures previously made in damaged parts of the scalp. He was able to see how the implants continued to grow in their new locations.

In 1943, another Japanese dermatologist,

Dr. Tamura, used micro-implants of 1 – 3 hairs to restore female pubic hair.

In 1943, another Japanese dermatologist, Dr. Tamura, used micro-implants of 1 – 3 hairs to restore female pubic hair. These small micro implants were obtained surgically by elliptical incisions made in the donor zone. As we can see he used a technique very similar to the one which was in use up until very recently. In spite of the fact that the work of Okuda and Tamura was published in Japanese medical journals, their procedures remained anonymous for some time due to the Second World War.

The hair transplant was re-discovered by Dr. Norman Orentriech in New York City in 1952, when he performed the first hair transplant on a male patient with androgenic alopecia. In 1959, Dr. Orentreich published his work after many years of rejection by an incredulous medical community. With him began the modern era of hair transplants. Unfortunately, his work was more orientated towards the punch technique by Okuda rather than the micro-implants used by Tamura, and so in the 1960´s hair restoration surgery began to progress, although in a somewhat incorrect direction

Factors influencing graft survival

Factors influencing graft survival

The progress made in the field of hair restoration surgery over the past 15 years has been remarkable.

Results are very natural looking and our understanding of full and receding hairlines has vastly improved. While outcomes are generally very good, with past reports of over 100% growth from grafts, experienced surgeons are still nagged by the inconsistencies of graft survival. Occasionally, grafts in an apparently excellent candidate will grow far less than 100% and the surgeon usually has no sound explanation. Many feel the answer lies within the basic fundamentals of hair restoration, but others believe that there are as of yet undiscovered factors which need to be disclosed.

X- and H-Factors

In the early 1980s, Norwood and Shiell proposed the term X-factor to describe unexplained poor survival of grafts beyond the control of the physician. They felt there was a little influence of X-factor in every case, but in 1-3% of patients it was significant. Norwood speculated that an autoimmune reaction might be involved. In 1994, Greco proposed the term H-factor to describe human errors leading to poor growth. He divided these into direct factors (manipulation, trauma) and indirect factors (drying, heat, staff fatigue).

What Affects Graft Survival?

  • The best answer is: “nearly everything.” The following are some of the primary factors to consider in graft survival:
  • Selection of patients whose donor hair is of sufficient quality and vigour to survive transplantation and future loss to baldness
  • Selection of patients with a recipient area of sufficient health to support the grafts
  • Avoidance of direct and indirect physical trauma to the grafts on the day of surgery
  • Graft size and method of preparation
  • Selection of the best storage solution (including additives) and the decision as to whether or not chill that solution
  • Creation of recipient sites so that instrument size, density of sites, and depth of sites do not damage the recipient bed to the point that they impede survival of the grafts
  • Finding the best plan of post-op care

While we are far from having the answers we seek, there are some very helpful studies and case reports to help guide us. The following is a list of categories believed to be important to survival along with pertinent reports from the literature. The holding solutions in these studies were chilled unbuffered normal saline (UNS) unless otherwise noted.


If there is one universally accepted factor in graft survival, it is hydration. In 2000, Gandelman, et al. published an article in Dermatologic Surgery studying 12 patients whose grafts were subjected to dehydration and trauma. Grafts were left on a surgical glove for 3 minutes and then examined under the light microscope (LM) followed by scanning and transmission electron microscopic (EM) analysis, if indicated. Major dam- age was observed by all modalities after dehydration—and planted dried grafts were found not to grow. This report was followed by a study by Beehner (Forum, 2007) in which 60 1-hair grafts and 60 2-air grafts were allowed to dry on a wet Telfa pad for 16 minutes before placing. The grafts were getting stiff but were not

brittle. Survival for 1-hair FUs was 60% and for 2-hair FUs was 82%, suggesting larger grafts give some protection against dehydration. Wetting the dried grafts before placing did not help.

In a busy transplant setting, it is easy to lose a few grafts in each case from drying. Drying at the cutting stations, drying on the gloves, and undetected “popped” grafts continue to create a slight attrition from dehydration. The cure is persistent vigilance throughout the procedure.

Physical Trauma

The second part of Gandelman’s 2000 study showed no visible damage to grafts on light microscopy following trauma (bending, crushing, and stretching with forceps) and therefore EM was not performed. They admitted that LM could not necessarily rule out biological effects.

Beehner found that soft crushing of the bulbs with a needle driver (rubber sleeves over the jaws) resulted in 64% survival versus a hard crush (35%). Interestingly, hard crushing of the bulge area resulted in a 0% survival for room temperature grafts versus 36% for chilled grafts, indicating that chilling provides a slight protection against physical damage.
Beehner and Frechet (2006 Annual Scientific Meeting of the ISHRS) performed a transection study on slit minigrafts (SMG´s) in which intact SMG´s were compared with SMG´s that were transected at some point along the follicle. In Beehner’s grafts, intact SMG´s had a survival of 86% at 6 months, but dropped to 65% at 12 months; while transected minigrafts had a survival of only 49% at 6 months, dropping to 45% at 12 months. Frechet’s transected SMG´s had a survival in the range of 35%.
These studies give evidence that trauma, including transection, results in a seriously reduced survival rate.

Time Out of Body

In one of the earliest and most quoted studies on FUs, Limmer (1992) recorded the following survival rates at different times out of the body. Using at least 200 FU grafts for each time frame, the survival was: 2 hours, 95%; 4 hours, 90%; 6 hours, 86%; 8 hours, 88%; 24 hours, 79%; 48 hours, 54%. A 1% loss per hour is a rough guide according to Dr. Limmer.

  • 2 hs ……… 95%
  • 4 hs ……… 90%
  • 6 hs ……… 86%
  • 8 hs ……… 88%
  • 24 hs ………79%
  • 48 hs ………54%

While it might seem that time out of the body is a predictable critical factor, Unger’s study on 4mm grafts planted within 2 minutes of removal had no increased survival over those planted after an hour and no improvement over the survival of Limmer’s FU grafts planted after 8 hours. Measuring survival at 4 months, 184 of 218 hairs (84%) reinserted at 2 minutes
survived compared to 212 of 218 (97%) reinserted at 60 minutes (Walter Unger, presenting to AAD meeting, Dallas, Texas, 1977). Perhaps measuring at 8 months would have revealed a higher survival rate.

In an attempt to find a method for delayed graft re-implantation, Kurata, et al. compared organ culture survival (as measured by hair shaft elongation) for follicles stored for various periods of time at 4°C in Hanks solution, Dulbecco’s modified Eagle’s
medium (DMEM), RPMI, and saline before culture with DMEM in a CO2 chamber. The pH buffers were not identified. After 24,36, and 48 hours storage, survival in saline was significantly lower than the other solutions; however, none of the grafts grew inorgan culture after 48 hours of cold storage in any of the solutions. Ten grafts were preserved for 7days in DMEM at 4°C then planted under the panniculus carnosus in athymic mice. At 5 months, 6 grafts were still growing. It is clear that long-term storage of grafts would be a significant advancement but is still a work-in progress.

Chilling versus Non-chilling

Using unbuffered normal saline, Raposio, et al. reported an 87% survival of chilled (1°C) versus 88% room temperature (RT)
(26°C) storage of grafts for 5 hours followed by organ culture for 10 days in Williams E media. No survival was defined as loss of normal follicular architecture. The hair shaft elongation rate between the two groups was also similar.

Jiange, et al. (2005) compared chilled storage in Ringer’s solution for 1–7 days at 0°C versus 4°C followed by (1) outer root sheath culture and (2) implantation under the panniculus carnosus of athymic mice. Survival following storage at 0°C was modestly better than at 4°C for all time periods of storage for both ORS cultivation and implant survival, with both categories showing no significant growth after cold storage for 7 days. Qian, et al. reported on human hair follicles implanted into athymic mice after several periods of storage at 0°C in Ringer’s solution compared to 0°C in DMEM culture media. Growth after 24 hours of storage followed by implantation into athymic mice for 5 months was 84% for Ringer’s versus 72% for DMEM. Results were also better with Ringer’s at 48 and 72 hours, but with considerably reduced survival. No regrowth was seen after being held in either solution for 7 days. The ability to culture outer root sheath cells after 24 hours of graft storage was also better with Ringer’s (95%) versus DMEM (86%).

The value of chilling is well established in general organ transplantation. Kidneys, for example, show up to a tenfold increase in survival time in chilled storage compared to room temperature storage. Hair follicles do not appear to be as sensitive to RT, but studies indicate that there is an increasing loss sometime after 6 hours. However, studies have not been continued long enough to know at what time period the break point occurs; therefore, more research is needed to determine the maximum room temperature storage time for hair follicles.

Holding (Storage) Solutions

Beginning in the late 1950s, hair grafts have predominantly been stored in unbuffered normal saline (UNS). Some of the best results reported in our field have been with the use of this solution. But is it the best solution or are grafts just pretty resilient? When compared to other storage solutions, saline has generally shown decreased survival. There have been quite a few articles written on the subject recently, but a few brief comments will be made here.

PH: Being unbuffered, UNS has a variable pH, usually in the range of 5.0. Normal human serum has a pH of 7.4. Increasing acidity has a known negative effect on tissue survival. The effect of using UNS on follicular tissue pH is not known at this time.
Researchers will generally buffer normal saline with phosphate (PBS) before conducting tissue studies. Plasma-Lyte A has a pH of7.4, using an acetate buffer. DMEM most commonly contains a natural bicarbonate buffer and is designed to be used at 37 degrees in vitro in controlled chambers with 5-10% CO2. In open air, DMEM can become alkaline and may not be healthy for hair grafts. DMEM used in hair studies normally contains the more expensive HEPES buffer, which works well in open air
situations. Advanced intracellular balanced solutions most commonly use HEPES, particularly in those meant to be chilled as it adapts to temperature changes. It should be noted that DMEM is not specifically approved as a transplant storage media
(personal correspondence with Sigma-Aldrich Co.).

Osmolality and electrolyte balance: Osmolality of normal serum ranges from 280–310 mOsmol/L. UNS has an acceptable osmolality of 308. Advanced solutions use osmotic buffers because there is a higher concentration of impermeable solutes intracellularly versus extracellularly. Membrane pumps are altered during cold storage. Adding impermeable solutes, such as lactobionate and dextran, as osmotic buffers helps to maintain the proper balance, particularly in chilled solutions.

Additives to holding solutions: In 1998, Swineheart found no significant difference in graft survival comparing storage in saline solution vs. organic culture medium (RPMI) both at 9ºC, with a survival measured at 5 months from 82% vs 84% ​​respectively.

Raposio, et al. (Derm Surg., 1998) reported that enhancing normal saline with ATP-MgCl and deferoxamine showed improved graft survival. Normal saline (control) was compared to the “enhanced” saline by storing grafts in these solutions at RT for 5 hours. Half of the grafts in the control and experimental groups were then placed in Williams E media and cultured in a  controlled CO2 chamber for 10 days. The grafts in the enhanced solution had a 98% survival rate compared to 87% for the
control. The other half of the grafts was studied by hair shaft elongation, which showed no significant difference in survival.

Currently, work is ongoing with ATP, which normally has difficulty crossing the cell membrane. By using liposomes, ATP is able to easily enter the cells; but because the liposome incorporates into the cell membrane, the membrane can weaken with too high a concentration. In addition, the freeze-drying of the ATP needed for this process is very expensive. For these reasons, work is being conducted to determine the effectiveness of a safer, inexpensive preparation (lipo tripolyphosphate) topically for ATP supplementation during the post-operative period in hair transplantation.

Ischemia Reperfusion Injury and HT Grafts

During transplantation, tissues develop ischemia. In organs susceptible to IRI, upon reperfusion and exposure to oxygen, the conversion of hypoxanthine (a breakdown product of ATP) to xanthine releases free radicals and reactive oxygen species—and starts a cascade leading to cell death by apoptosis or sometimes necrosis. The free radicals released by apoptotic cell death (ACD) are particularly damaging to the double strands of DNA and the cell membrane, where they cause lipid peroxidation. This lipid peroxidation of the cell membrane releases malondialdehyde (MDA) and 4-hydroxy- alkenals (HAE), which are considered measurements of IRI. DNA breakdown during ACD can be measured by cytoplasmic histone-associated DNA fragments (HADF).

Most transplanted organs are surgically reconnected to the body’s blood supply and are exposed to a sudden dramatic rise in oxygen tension. In contrast to common organ transplants, hair grafts are perfused passively for at least 3 days before being re- vascularised, thus not receiving a sudden “blast” of oxygen. For this reason, some question exists whether IRI occurs in hair transplantation. Cooley used the MDA assay to test 150 grafts in 7 patients. The test grafts were placed into the scalp and later removed to complete the ischemia/reperfusion cycle and then tested against control grafts that were never re-implanted. The MDA assay in test grafts revealed MDA levels elevated 200–600% over controls. Krugluger, et al. demonstrated a dramatic rise in HADF after 36 hours of culture in serum containing DMEM culture media. In addition, HADF was significantly reduced by storage in media containing antioxidants. In yet another study, Krugluger reported better growth and less shedding after adding various antioxidants to holding solutions. While more studies are needed, there certainly appears to be reasonable evidence for the existence of IRI and ACD in hair grafts.

Platelet Rich Plasma

There is currently considerable interest in platelet rich plasma (PRP). PRP is rich in growth factors, among which are platelet derived growth factor (PDGF), transforming growth factor beta-1 (TGF ß-1), and vascular endothelial growth factor (VEGF). PRP has been used with benefit in both the donor strip and also grafts before placement. In 2005, Uebel presented a study in which grafts were dipped in the PRP created on the day of surgery from the patient’s blood. Grafts were dipped into the PRP for 15 minutes before implanting into the scalps of 23 patients. There was a 15% increase in graft survival in the PRP side compared to controls. PRP also looks promising in donor and recipient site healing. The negatives are that it is a little cumbersome and expensive to prepare.

Freezing for Long-term Graft Storage

In 2002, Adanali, et al. reported that grafts frozen for 2 weeks at –20°C (standard freezer) showed no damage under LM examination, suggesting that this might allow long-term graft preservation. In response, Jimenez performed a study of 150 grafts frozen for 1 hour, 5 days, and 7 days at –20°C before implantation. Survival after freezing for 1 hour was 20%; 5 days, 0%; and 7 days, 0%. This demonstrates the unreliability of LM to evaluate survival. At –20°C, ice crystals are constantly forming and reforming, killing the cells. Freezing tissue for storage requires much colder temperatures in order to create a “glass formation state” (no crystal movement), usually with liquid nitrogen. This is an involved process using cryoprotectants in which modifications for tissue type and timing of the freeze/thaw are critical

10 UF/cm2 ………. 97%
20 UF/cm2 ………. 92%
30 UF/cm2 ………. 70%
40 UF/cm2 ………. 79%

An important and often-quoted study on 2 patients by Mayer, et al. in 2000 compared 2-hair FUs planted at various densities and measured at 8 months. Results showed the following survival: 10/cm2, 97%; 20/cm2, 92%; 30/cm2, 70%; 40/cm2, 79%. All sites were made with an 18g needle, which is quite large by today’s standards. In a 2006 study, Beehner studied 2 patients using densities of 20 and 30/cm2 into 19g needle sites and 40 and 50/cm2 into 20g needle sites. Results showed the following: 20/cm2 (95% patient 1, 87% patient 2); 30/cm2 (93%, 92%); 40/cm2 (70%, 100%); 50/cm2 (67%, 94%). While the results are inconsistent, this study seemed to indicate that recipient site size is important. A recent yet unpublished study tends to verify this, showing 98–100% survival at densities of over 60 and 70 FUs/cm2 while using small recipient sites. Survival at higher densities is influenced by a variety of factors, the most important of which are the site size, tissue handling, donor hair quality, and recipient site quality. Doctors new to the field would be well served to increase density slowly.

Skinny vs. Chubby

In 1997, Seager performed a study on 88 “skinny” grafts in which trimming left the papillae with no surrounding tissue and compared them to 163 “chubby” grafts in which ample surrounding tissue was left. The survival rate was 89% and 113%,
respectively. In 1999, Beehner compared survival in 60 “skinny” and 60 “chubby” grafts, but left an equal amount of tissue surrounding the dermal papillae. Result survival rates were 101% and 133%, respectively. More recent studies have not shown
survivals much in excess of 100%, possibly due to better counting techniques. Regardless, it appears healthier for the grafts to leave a little tissue beyond the dermal sheath and papillae. Planting trauma and graft dehydration may be reduced with having just a little extra tissue.

Intact versus Non-intact Grafts

In 1999, Beehner performed a study comparing intact FU´s compared to grafts with the same number of hair follicles but containing follicles from two adjacent FUs that were subdivided. The grafts containing follicles from subdivided FUs actually had a slightly better survival rate, though not significant. From this study, it appears that it should be safe to divide FU´s, if needed.

Lateral (Coronal) vs. Parallel (Sagittal) Grafts

In 2006, Perez and Parsley performed a study using 2-hair grafts planted both laterally (l) and parallel (p) at densities of 30, 40, and 50 grafts/cm2. Results: 30/cm2, 70% (p) vs. 100% (l); 40/cm2, 86% (p) vs. 92% (l); 50/cm2, both 105%. All sites were made with a 19g needle. This small study, along with a general overview of results around the world, would tend to indicate that there may be no significant differences in survival using lateral versus parallel grafts.

30 UF/cm2………. P: 70%
L: 100%
40 UF/cm2 ………. P: 86%
L: 92%
50 UF/cm2 ………. P y L: 105%


In the July/August 2007 issue of the Forum (Vol. 17, No. 4), Rinaldi, et al. used a twice daily topical post-op solution containing adenosine sulfate 0.1%, taurine 1.0%, and ornithine chloride 1.0% (called 1-3 atodine). Adenosine sulfate up regulates vascular endothelial growth factor (VEGF) and follicular growth factor-7 (FGF 7), while taurine and ornithine stimulate outer root sheath growth. At 1 month, vessel diameter and hair shaft diameter were both larger than the placebo.

Revascularization (using reflectance confocal microscopy) of the grafts was quicker by nearly threefold, and the follicle growth was improved. Could one of the keys to improved graft survival reside with VEGF? Yano, et al. demonstrated that perifollicular angiogenesis correlated with up-regulation of VEGF mRNA expression in murine outer root sheath keratinocytes, but not in dermal papillae cells. The role of the ORS being the primary site of VEGF up-regulation was also found in a study by Krugluger, et al. Transgenic over-expression of VEGF resulted in a strongly induced perifollicular angiogenesis; resulting in increased hair growth, follicle size, and shaft diameter. Systemic neutralizing anti-VEGF
antibodies resulted in poor hair growth and reduced follicle size. Because the outer root sheath is more accessible to topical therapy than the dermal papillae, it is easy to speculate that the topical 1-3 atodine solution
mentioned in the previous paragraph might be effective.

General Impressions

We have looked at graft survival from many viewpoints, but we have not yet satisfactorily uncovered some of the factors leading to inconsistencies in growth. In this author’s opinion, part of it may lie in the recipient bed and the speed of revascularization. Grafts placed inmediately after harvesting don’t seem to grow significantly better than those placed several hours later. Rinaldi’s use of topical 1-3-atodine solution post-transplantation, the effects of PRP, the use of inhibitors of iNOS, and the work on up-regulating VEGF are all exciting. Grafts may take 3 or more days to re-vascularise. Anything to speed this process or support them in the interim logically might help. Preconditioning of grafts with growth factors and antioxidants while out of the body is also very promising. Additionally, isolated cases suggesting improved hair growth using hyperbaric oxygen (HBO) are encouraging, especially when one considers studies showing improved skin graft and flap survival with HBO. It should be pointed out that oxygen therapy is known to stimulate angiogenesis.

In conclusion, there is much to be learned about hair graft survival. Fortunately, interest in research is growing rapidly.

William M Parsley MD
Translation: Dra. Ximena Vila

Aesthetic treatment for hair

Maintaining great hair for life

There are many causes of hair loss including disease and genetic predisposition. Yet, the most common reason men and women experience hair loss is due to poor cosmetic grooming practices.
Scalp scratching
Even though mild to moderate seborrheic dermatitis does not cause hair loss, the scratching associated with the scalp pruritus can definitely predispose to hair loss. It is possible to remove all of the cuticular scale off of a hair shaft with only 90 minutes of continuous scratching by the fingernails. This loss of cuticle leaves the hair shaft weakened and permanently cosmetically damaged. Thus, treatment of scalp itch is important to preventing hair loss.
Long hair vs Short hair
Long hair is much more likely to be cosmetically damaged than short hair. Therefore, patients who have extensive hair damage may wish to select a shorter hair style to maximize the appearance of the hair. In this case, it is extremely important to identify the cause of the hair damage so that the newly grown hair remains healthy and cosmetically attractive.
Age-related factors
It is a well-known fact that hair growth slows down with age. This means that cosmetically damaged hair will be preset longer on mature individuals. Also, the diameter of the hair shaft decreases with advancing damage from chemical processing. For this reason, all chemicals used on mature hair should be weaker than those used on youthful hair.
Hair combing and crushing
Hair combing is a daily grooming ritual that frequently causes hair damage and loss. Hair should only be combed when dry, if possible. Wet hair is more elastic than dry hair meaning that vigorous combing of the moist fibbers can stretch the shaft to the point of fracture. The ideal comb should be made of a flexible plastic and possess smooth, rounded, coarse teeth to easily slip through the hair.Extensive hair brushing should also be avoided while hair is wet. A good brush should have smooth, ball-tipped, coarse, bendable bristles. The brush should not tear the hair, but rather gently glide. Brushes used while blow drying hair should be vented to prevent increased heat along the brush, which could damage hair. Patients should be encouraged to brush and manipulate their hair as little as possible to minimize breakage. Older teachings that the hair should be brushed 100 strokes a day and the scalp vigorously massaged with the brush should be dispelled.
Hair clasps
Common sense applies to the selection of appropriate hair pins and clasps. Rubber bands should never be used; hair pins should have a smooth, ball-tipped surface; and hair clasps should have spongy rubber padding where they contact the hair. Loose-fitting clasps also minimize breakage. The fact remains, however, that all hair pins or clasps break some hair since they must hold the hair tightly to stay in place. To minimize this problem, the patient should be encouraged to vary the clasp placement so that hair breakage is not localized to one scalp area. This problem is particularly apparent in women who wear a ponytail. These women frequently state that their hair is no longer growing when in actuality it is repeatedly broken at the same distance from the scalp due to hair clasp trauma. Pulling the hair tightly with clasps or braids can also precipitate traction alopecia.
Hair cutting techniques
The hair should always be cut with sharp scissors. Any defect in the scissor blade will crush and damage the hair shaft. Crushing the end of the hair shaft predisposes to split ends.
Hair styling product use
Hair styling products are an important way to improve the cosmetic appearance of the hair shaft, but should always leave the hair shaft flexible. High hold stiff styling products can actually precipitate hair breakage when trying to restyle the hair with combing.
Hair colouring and bleaching
Hair colouring and bleaching are universally damaging to the hair shaft. It is sometimes said that chemical processing adds body to the hair. This means that the dyeing procedure allows the hair to stand away from the scalp with greater ease. This is not due to better hair health, but rather due to hair damage that makes the hair frizzy and more susceptible to static electricity. The basic rules of fair dyeing are always stay within you colour group preferably dyeing the hair no more than 3 shades from the natural colour.
Hair relaxing
Hair relaxing is weakening to the hair shaft, but can actually facilitate hair length in patients with kinky hair. This is due to decreased hair breakage during combing. The relaxing procedure straightens the hair and makes it easier to groom, but the grooming should be done gently to avoid hair shaft fracture.
Hair permanet waving
Lastly, hair permanent waving is also damaging. The curls should be as loose as possible with the interval between procedures as long as possible. For patients with damaged hair, the perming solution should be weak and left in contact with the hair for as short a period as possible.Zoe Diana Draelos is a board certified dermatologist in private practice and a primary investigator for dermatology consulting services, a company she founded in 1988 to provide education, perform adverse reaction evaluation, and conduct clinical studies in association with the pharmaceutical and cosmetics industry. She has been the recipient of numerous research grants and has served as also a contributor to the medical literature, with more than 200 articles and 25 book chapters to her credit. She is the author of several textbooks and serves on many editorial boards.Surface; and hair clasps should have spongy rubber padding where they contact. the hair. Loose-fitting clasps also minimize breakage.
Translation: Dr. Lorenzo


Does hair renew itself, that is to say, is it normal that hair falls out?

Does hair renew itself, that is to say, is it normal that hair falls out?
The hair follicle doesn´t grow continuously but is produced in distinct phases which make up the hair cycle. There are three basic and well known phases of hair growth:
Anagen: This is the phase of active growth. The live cells at the base of the hair follicle actively grow and eventually form a compact column which extends upwards to the surface of the skin. Afterwards a keratinized area forms on top of where the active division of the cells occurs. Live cells become dehydrated, and on death are converted into keratin. Finally the keratin filaments are cemented together by a cistine rich matrix. The area known as the dermal papilla, situated just below the area of active follicular cell division, plays an important role in controlling the growth cycle. In a scalp with hair, normally 90% of the hairs are in this phase which lasts for three months.
The rate of growth in the scalp is approximately 0,035 mm per day or 1cm per month.
Catagen: During the catagen phase, the base of the hair is keratinized and forms a lump called a club, which begins to separate from the dermal papilla. It then moves to the surface while remaining connected via a fine filament of connective tissue. This phase lasts for 2 or 3 weeks. Its a degenerative phase in which the hair begins to fall out to be later regenerated.
Telogen: This is the rest phase. The adherence at the base of the follicle becomes fragile until the hair finally falls out. This phase lasts for 3 or 4 months and generally is what happens after a hair transplant. For this reason, there are no signs of significant growth in the grafts until after this phase. On top of that, when there is native hair present in the receptor area, some of these hairs will be affected by surgical trauma and will enter into a catagen-telogen phase. This causes a temporal but greater initial loss of hair, which is called telogen effluvium. Normally around 10% of hair follicles in a scalp with hair are in the telogen phase. When the quantity of hair being lost exceeds the percentage of hair in growth, the hair begins to look thin and bal
Why does baldness occur?
Androgenic alopecia occurs as a result of the gradual conversion of terminal hairs (healthy and dense) into soft or down hair (pale and microscopic). It is a hereditary condition and appears to be controlled by an autosomic dominant gene which is related to sex. The expression of this gene depends on the amount of androgens circulating.
Testosterone is the main androgen circulating in masculine blood, while in the female blood the steroid dehydroepiandrosterone sulfate, androstenediol sulfate and 4-androstenediol are the predominant proandrogens present. A proandrogen is a steroid which can be converted into an active androgen by enzymatic action in a specific tissue. Similarly, the enzymatic reduction of testosterone and the previously mentioned androgens by 5-alfa-reductase is necessary for the induction of androgenic hair loss, for both men and women.
The initial signs of thinning are clearly related to puberty in males when the levels of testosterone begin to increase, gradually converting hair into soft or down hair. Initially, this results in the recession of the front hairline or the crown, and depending on the genetic characteristics, can progress into the parietal zone forming a strip along the temporal and occipital areas. 


Front line reconstruction

Reconstructing the front hair line

Reconstructing the front hair line
The design and position of the front hair line are critical to obtain natural looking results after a hair transplant. The objective is to achieve a mature hair line in harmony with the patient’s age.
The size and form of the head varies from one person to another and so too does the position of the hair line.
Generally, a distance of around 8 cm (4 fingers) above the eyebrows works well as the lowest starting point for the hair line, although in some cases we have to increase or decrease this distance depending on the facial aesthetics and the size and shape of the head. How the face and head interrelate, their proportions and the available donor zone are also important factors.
The most important factor of hair restoration surgery is that the restored hair appears as natural looking as possible. The basics for the artistic distribution of the front hair line are:
Correct positioning of each follicular unit. Normally hair grows upwards at an angle of between 45 and 60 degrees in the central part of the front hair line and as we move outwards to the sides it changes its direction of growth and the angle decreases. The implanter allows us to position each follicle at the required angle.
The very front line of transplanted hairs is made with follicular units consisting of single hairs only which are placed with high density and are distributed in random pairs. Behind the first line we use units of 2 hairs in the same distribution pattern, increasing to 3 or 4 hairs as we come closer to the posterior regions.
The density of the front line and the front third of the scalp have to be maximum.
The appearance of fullness is directly related to the hairs mass, which is in turn related to the number of hairs, thickness, texture, colour and curliness of the hair. The appearance of fullness is also affected by the contrast in colour between the hair and the scalp. The average density of hair in patients with no hair loss is around 70 follicular units per cm2 (around 200 hairs), but only 50% of this number is required to achieve the appearance of normal density, 35 F.U.´s per cm2 (100 hairs per cm2). At injertocapilar.com all of our reconstructed front hair lines have densities above 45 follicular units per cm2.

Classifying hair loss

Classifying hair loss

Classifying hair loss
To classify the severity of alopecia, a number of categories have been created which divide the loss of hair into several stages.  This classification is useful for describing hair loss and how the pattern of hair loss has progressed, particularly when it follows the predictable pattern of androgenic alopecia, be it in men or women. The guide most commonly used for men was developed by Dr. Hamilton and later modified by Dr. Norwood resulting in the so called Norwood-Hamilton Scale.
Women suffering from androgen alopecia experience a pattern of hair loss which is somewhat different from that of men
Hair loss in women is seen as a diffuse decrease in the thickness of each hair over the whole scalp. There is also a scale to classify hair loss in women called the Ludwig Scale. But there are also exceptions and in some cases men suffer from diffuse thinning of the hair while women may experience similar hair loss patterns as men do.


After transplant

Signs and symptoms after a hair transplant

1st & 2nd day postoperative:

Receptor area:  Apply saline solution every 1.5 hours. There may be a slight inflammation of the forehead or in between the eye brows due to the use of local anaesthetic. This will last a maximum of 3 or 4 days.

Donor area: Slight discomfort only when pressure is applied to the extraction zone. Feeling begins to return to the area and the “helmet” sensation produced on the day of the intervention from the anaesthetic disappears.

3rd day:

Receptor area: The inflammation of the forehead, if it has occurred, begins to disappear. There is a slight tightening or “cork” feeling (a decrease in sensibility) which may last around 10 – 15 days depending on the number of units transplanted. The patient begins to wash their head with Johnson´s Baby shampoo or FLEX by Revlon (for normal hair), depending on the doctor’s instructions. The hairs feel hard, like beard hair after 4 days. It is no longer necessary to apply the saline solution (although the patient may continue its use if so desired).

Donor area: Painless. The sensation of itch begins due to the healing of the tiny wounds and the shaving of the head. Saline solution may be applied and/or a sedative can be taken to relieve the sensation. A slight discomfort may appear at the nape of the neck due to the use of local anaesthetic in the area.

1st week:

Receptor area: Between the 7th and 10th day all of the scabs and flakes of skin will disappear leaving behind only a slight redness (which may last for around 20 days) as well as the newly transplanted hair. There may also be slight peeling of the skin during the next 30 days.

Donor area: The small wounds have completely healed. The hair has grown sufficiently such that it is difficult to notice there has been any kind of surgery.

2nd week:

Receptor area: The scalp is clean of scabs and flakes. The only evidence, if any at all, is a slight redness.Donor area: This area is now forgotten about, without any mark and well on the way to recuperation

2 to 8 weeks:

Receptor area: This is the phase in which the transplanted hairs begin to fall as they enter the telogen or rest phase (telogen effluvium) due to the shock of transplant. There may be a loss of up to 70%, higher or lower, depending on the person. When the units are implanted in between hairs, the native units may also suffer shock (shedding or shock loss) and enter a rest phase. Our occurrence of this is 5% and in such an event the native hairs are recovered in 3 -4 months. It is only a temporary complication.

Donor area:  This area continues to recover. There are no signs of any surgery.

2 to 4 months:

Receptor area: During this stage the patient is waiting expectantly. In the majority of cases the transplanted hair begins to grow between 3.5 and 4.5 months. After undergoing slight shedding or shock loss the native hair also begins to grow.

Donor area: 4th month and this area is now completely healed. The zone can even be evaluated for another intervention if so required

4 to 8 months:

Receptor area: The transplanted hair begins to grow, firstly as fine slightly twisting hair which later takes form with more normal body, volume and texture. After the 3rd or 4th month vitamins are prescribed for hair and nails to guarantee that the growing hair has all that it needs.

8 months:

Receptor area: The transplanted hair continues to grow. We have now achieved approximately 80% of the definitive result

8 to 12 months:

Receptor area: The transplanted hair continues to grow in number (there is only around 10 – 15% so the change won’t be as evident as it was between months 4 and 8) and in thickness. If there was any change in texture in the new hair it tends to recover in these months. Definitive result is at one year from the date of intervention

What can we expect

What can we expect after undergoing a hair transplant surgery?


Many in the profession will say that we can return to work the next day. This is not entirely correct for all techniques, that is to say, the post-op and consequently the discomforts of a hair transplant depend on the technique used during the extraction phase. The individual extraction technique is minimally invasive and without incisions or stitches meaning that the discomfort felt in the donor zone is well within tolerable levels after 24 hours. The strip technique, however, is not a minor surgery; a flap of skin from 10 to 22 cm long is removed, so patients should be forewarned that the recovery period is longer.

Post-operative instructions

Have a light and easy-to-chew meal after the procedure.

Don’t take any alcoholic drink for 2 days after the procedure.

Don’t take any aspirin or any other medicine which contain acetylsalicylic acid.

Don’t take any vitamin supplements.

Take the medication recommended by injertocapilar.com and always take it after meals.

Relax for the rest of the day of the procedure.

Under no exception should you scratch or touch the small scabs (if present) in the donor or receptor zone. It’s very important to keep the scalp clean and free of germs from your hands or nails.

For those patients who are taking cortisone to prevent inflammation in the forehead, we recommend that you avoid salt in your meals during the 5 days after the procedure.


To prevent any problems with the stitches in the donor area, do not perform any exercises or brisk movements. This includes leaning forward to tie your laces, as this movement can create tension on the stitches of the donor zone. No exercise during the first 3 weeks after the procedure.


one of our doctors in injertocapilar.com will remove the stitches 10 – 12 days after the procedure.

 IF YOU USE A HAIR PIECE: you should wait at least one week after the procedure before using it again.


IMPORTANT: Do not use any chemical product on your hair for one month after the procedure (dye, hair-spray, gel, foam, etc…).


Receptor Area: saline spray every 2 hours except when sleeping. No washing but the grafts should be free of blood.

Donor Area: wash the area ONCE A DAY,  and very carefully with your fingers (not your nails) and using lukewarm water.

For the  STRIP technique with stitches, use medical shampoo with Betadine. You will notice some discomfort, tension and slight numbness.

For the FUE technique without stitches, use pharmacy shampoo Penaten or baby shampoo, pH 5.5. You will notice very little discomfort, no tension or numbness.

DAY 3 TO 15:

Wash the hair twice daily, morning and night with pharmacy shampoo Penaten or baby shampoo, pH 5.5.

For the first 4 days use only the palms of your hands and fingers gently.

It’s IMPORTANT to gradually increase the pressure to the scalp as the days go by.

NEVER use your nails

If there are small scabs, leave the shampoo in for a few minutes before rinsing and these will disappear

If you use Minoxidil lotion you can continue to use it 3 or 4 days after the procedure.

If it irritates the scalp then reduce the dosage to just once a day or wait for another week before continuing treatment


Wash your hair with the aforementioned shampoo. 


You can return to using you normal shampoo.

Medical treatment

External therapy: Minoxidil

MINOXIDIL:Minoxidil was approved in 1988 by the American FDA for use in males in a 2% solution, and in 1991 for use in women at the same concentration.  Subsequently, in 1997
it was approved for use in men in a 5% solution.
In the USA both concentrations are available commercially in foam or lotion format while in Spain only the lotion format is commercially available.
The 5% solution has not yet been approved for use in women 
although it has been used globally by many dermatologists in made to order prescriptions.
Mechanism of Action
Minoxidil is a potent vasodilator 
and is administered orally for the treatment of arterial hypertension. A side effect of hypertricosis was observed in patients who were taking the medicine for more than one year. The exact mechanism of action at the level of the hair is still not exactly understood. It doesn’t appear to have any hormonal or immune-suppressor effects, but it has demonstrated a direct stimulating effect on the epidermis cells and developing hair bulbs. It has been shown that it prolongs the survival of the keratinocytes. And lastly, it is known that it acts by stimulating the opening of potassium channels, which provokes hyperpolarisation at the cell membranes. These conditions cause a decrease in the chance that other ionic channels would open, such as sodium, chloride or calcium channels. Calcium channels are suspected in playing a part in the inhibition of hair growth. Contrary to popular belief, local vasodilatation would appear to not have an important role in hair growth.
Treatment with minoxidil leads to a thickening of the hair is affected zones,
beginning with down hair and growth being observed in terminal hairs in a period up to 12 months, in masculine alopecia as well as female. A better result is seen in those patients who don’t have total hair loss in the affected zone as the increase in density is mainly due to miniaturized hairs becoming terminal hairs rather than the growth of new hair. This occurs in a period of no less than 4 months after first starting to use this product, and continuing its progress until reaching definitive results after one year. At the beginning (after approximately 20 days) there may be a slightly more hair loss than usual which is normal and expected and should not be a motive for suspending treatment. This happens as a result when minoxidil “assembles” a large number of follicular units which enter into a rest or telogen phase which after 3 – 4 months begin to generate new hairs all at the same time. The hair loss then stabilizes after the initial period of re-growth.
The application of minoxidil should continue as long as the hair loss is a problem for the patient, since the suspending treatment leads to a loss in effectiveness and a possible return to the initial state
of the alopecia in around 4 months. Treatment consists of external applications made twice daily during the entire time that the product is being used. Those patients who begin to apply the product only once a day may notice a reduction in their hair count after 12 months. Minoxidil should be tried for one whole year before evaluating its therapeutic effectiveness. This is evaluated by the patients satisfaction and comparison of photos by the doctor.
Only a certain improvement is obtained during treatment.
Minoxidil, external solution of 2% and 5%, is used for the treatment of masculine alopecia in the front-parietal and parietal-occipital regions and for diffuse feminine alopecia,
both of androgenic origin. It is effective, especially on the crown area, where it preserves if not reduces the horizontal diameter of the alopecia. Although confirmative statistics don’t yet exist, the combined use of minoxidil and finasteride in men has a synergic affect which increases the benefits of that either can provide on their own.
The patient should use 1 millilitre of minoxidil solution two times a day.
The drops should be applied directly onto the dry scalp and be spread around with the fingers (massage or friction not required). The dosage should be applied equally independently of the extent of hair loss, as the amount applied is absorbed and acts on the whole scalp. The maximum recommended daily dosage is 2 ml.
The best way to apply it is to place 1 ml of the solution in a small syringe (the kind used for insulin) and perform three runs along the scalp from the crown to the front hairline or vice versa and then spread it around the whole area. 
A spray atomizer is not recommended as a large part of the solution will be applied to the hairs, where minoxidil is ineffective and is thus wasted.
Minoxidil can be formulated with 0.025% retinoic acid to augment the effectiveness as this increases the anagen phase and favours the penetration of the minoxidil. When retinoic acid is added to minoxidil, however, the probability of local irritation increases and isn’t always tolerable.
Side effects:
Minoxidil is very tolerable and the side effects are mainly dermatological in nature.
The most frequent unwanted effect is irritable contact dermatitis characterized by intense itching, redness and intense flaking of the skin. In the majority of cases this is caused by the carrier responsible for the absorption of minoxidil into the skin which is the ethanol’s (alcohols): propylene glycol (PPG), polyethylene glycol (PEG) or ethylene glycol (EG). Any of the aforementioned symptoms are sufficient motive to suspend the medication and consult a specialist. The contact dermatitis produced can be bad enough to cause a 40% increase in hair loss, a reaction called Chemical Telogen Effluvium, which as unpleasant as it is, is usually temporary and clears up in 3 – 4 months. The frequency of irritation in the scalp is approximately 7% for the 2% solution users and may be slightly higher with the 5% solution simply because the concentrations of the solvents are higher in these solutions. Bibliographic studies indicate that to date around 20% of the population is sensitive to these solvents without knowing it.
Occasionally the active ingredient of minoxidil may cause allergic contact dermatitis but the percentage of these cases is less than 10%.  If patients experience contact dermatitis with the 5% solution, they should stop treatment until all symptoms have cleared up and they should also stop using any products that have the initials PPG, PEG and EG. Minoxidil solution shouldn’t be used again without consulting a doctor as it’s very unlikely that tolerance to this side effect can be developed. In these cases the use of minoxidil may never be a productive measure.
Although less frequently, other effects may be observed such as acne, increased hair loss and facial swelling. Facial hypertricosis (growth of undesired hair) in the eyebrow, cheek or jaw regions may be observed in 3 – 5% of women but doesn’t seem to be a problem in men. An explanation for hypertricosis has not yet been found, although it is possibly due to a systemic effect of the inadvertent application of the medication to these other areas. Hypertricosis is completely reversible after the suspension of the treatment. It is important that patients wash their hands after application and that care is taken so that not a single drop falls outside of the scalp area.
In the case that any of these reactions occur, the patient should stop using minoxidil and consult their specialist. Contact with any mucous surface should be avoided, mainly the eyes, as this would cause irritation and burning. If this occurs the eyes should be rinsed well with cold running water.
The effects of minoxidil during pregnancy and lactation are unknown, so its use is not recommended without first consulting a doctor. Up to now there have been no human trials carried out, although alterations have been seen in rats and rabbits. Minoxidil taken orally is secreted in human mother’s milk.
The accidental ingestion of minoxidil may incur significant side effects (each millilitre of 5% solution contains 0.05g of minoxidil); in these cases the patient should quickly go to the hospital emergency services.

Systemic therapy: Finasteride

Medicinal Systemic Therapy  
Includes finasteride and the anti-androgens, mainly cyproterone acetate.
In 1997, the FDA approved the use of finasteride at a dosage of 1 mg per day for males suffering from androgenetic alopecia. It has been available in Spain since 1999.
Mode of action:
Finasteride is a synthetic analogue of testosterone which acts in competition as the predominant inhibitor of 5-alfa-reductase, type 2, which is an intracellular enzyme that converts testosterone into dihydrotestosterone (DHT), a potent androgen responsible for the progressive miniaturization hair follicles. Its specificity is caused by its extreme affinity for the type 2 isoenzyme over the type 1. By inhibiting this enzyme, the conversion of testosterone into dihydrotestosterone is blocked, producing significant reductions in the levels of DHT in fluids and tissues. It has been demonstrated that the preferred location of the type 2 iso-enzyme in the scalp is in the hair follicle, over the type 1 iso-enzyme, which is predominantly located in the sebaceous glands. This explains its specificity of action on hair loss.
Finasteride is administered orally in a 1 mg/day tablet which, as stated earlier, is the FDA approved dosage for the treatment of androgenetic alopecia. It can be taken at any time of the day, with or without food, and it hasn’t shown any significant interactions with other medications. Daily administering of the drug produces an accumulation of levels in the blood which reach a certain stable concentration necessary for it to take effect. This is produced approximately between the third and fourth month since beginning the treatment (this is when it begins to affect the hair and side- or adverse-effects begin, if any) and is maintained as long as the patient continues taking the medication. If the patient forgets to take a tablet, the level of medication in the blood doesn´t abruptly drop, so that the next day the dosage can be resumed without having to take two tablets together. If the patient stops taking finasteride (whatever the reason may be) the concentration of the drug in the blood decreases and disappears completely between the second and third month. This means that it still has an effect during this period in spite of there being no more tablets administered.
Propecia, the commercial name for finasteride in 1 mg tablets, is currently the only brand registered and authorized for the treatment of androgenetic alopecia. On that premise, and independently of the industrial and commercial property rights over the active ingredients, Proscar broken up into smaller fragments (5 mg tablets of finasteride) or any other variety of finasteride (capsules, medications prepared by the pharmacy, etc.) which are used for the same purpose should also be interchangeable with the Propecia 1 mg tablets. On one hand, there are issues of ethics, legality, variability in dosage and security which accompany the breaking up of Proscar tablets. On the other, there are advantages such as deregulation and availability of finasteride apart from the commercially distributed tablets.
Adverse side effects:
The adverse side effects observed in finasteride are produced in the fourth month since taking the medicine and are reversible two or three months after suspension of treatment, when it has been completely eliminate from the blood.
A study which was published in an important scientific journal, The European Journal of Dermatology in 2002, titled “Long-term (5 years) Multinational Experience of finasteride 1 mg in the treatment of males with androgenetic alopecia” shows results obtained from the comparison of a population of 1553 males with AGA who were randomly divided into two groups and were administered finasteride 1mg/day to one group and a placebo (tablet composed of excipients only without any effect) to the other group.
The effects uncovered were seen in less than 1% of participants and are summarized in the following list:
  • Reduction of the libido (1.8% in the finasteride group and 1.3% in the placebo group during the first year. In the fifth year these figures became 0.3 vs. 0 respectively).
  • Erectile dysfunction (1.4% against 0.6% after a year and 0.3 vs. 0 respectively in the fifth year)
  • Reduction in the volume ejaculated (1.4% against 0.9% which in the fifth year became 0% in both groups).


Very infrequently there have been published cases of gynecomoastia, testicular pain and hypersensitive reactions to a 1 mg dosis of finasteride which were reversible on suspension of drug.

When considered separately, there was no significant difference in adverse effects in the placebo group but there was when they are considered globally, 3.9% (finasteride group) versus 2.4 % (placebo group). The adverse effects simultaneously reduce during the months after in 58% of those who continue the treatment, they are completely reversible after suspension of the drug. A recent study confirmed that a 1 mg daily dosis of finasteride taken during 48 weeks does not affect spermatogenesis or production of sperm in males between the ages of 19 and 41.

Long term effects are still unknown, although there are no known systemic adverse effects. A study carried out by the American Urological Association on “Recommendations for  the prophylactic use of finasteride against prostate cancer” demonstrated that finasteride in dosages of 5 and 1 mg reduce the size of the prostate, the levels of PSA (prostate specific antigen used to detect cancer in the prostate) and DHT. So while it can´t be said that finasteride 1 mg eliminates the risk of cancer, it does reduce its occurrence.

It´s not necessary for any specific laboratory test, but it is feasible to ask for a base analysis before prescribing the medication. In this way, previous changes can be detected, which if done later couldn´t be attributed to the drug.

Use in women – Teratogenicide:

Even though the FDA has not yet approved the use of finasteride in women, there are studies looking at the use of finasteride in women who suffer from androgenetic alopecia. Several studies have shown that finasteride 1 mg/day gave no results whereas the use of 2.5 to 5 mg/day showed more encouraging results. An example of this can be seen in a study performed by Lorizzo et al. in which there was an improvement in the alopecia in 23 out of 27 women in pre-menopause (associated with an ant conceptive composed of drospirenona and ethinly estradiol).  Another study was presented by Trueb (5 post-menopausal women treated with 2.5 or 5 mg finasteride) which showed positive results. These are only examples but there is still a long way to go and much research to do.

Finasteride is categorized as X for pregnant women, as being an anti-androgen means that it can feminize a masculine fetus.  Its use in women of fertile age is strictly forbidden unless they are using anti-conceptive measures. Women of fertile age not only shouldn´t take finasteride nor should they touch broken or squashed tablets.  Nevertheless, unless there is a breakage in the women’s skin, significant percutaneous absorption is unlikely to occur. Finasteride tablets have an impermeable coating which prevents contact with the active ingredients during handling. In theory there is a risk, although highly improbable, of deformations of the sexual organs of the masculine fetus if the couple have sexual relations during the stages of pregnancy when the sexual organs of the fetus are developing (in the 8th and 15th week of gestation). That said the quantity of the drug found in semen is very small and considered to be insufficient to cause any damage to the masculine fetus. A report from a laboratory that fabricates finasteride stated that they measured the concentrations in semen of 35 males who were taking 1 mg per day of finasteride during 6 weeks. In 60% of the samples (21 of 35) they could not detect any finasteride. Therefore, when using finasteride, only a very very small part of it goes to the semen. However, even if it weren´t so low, it still wouldn´t cause any problems. The transfer of finasteride, from semen to the women through the vaginal wall was not detected in the many examinations performed to date. The risk of teratogenicide in humans has not been evaluated, only in experimental animals, in which abnormalities were caused in the urogenital system. To date there are no studies which evaluate if the oral ingestion of semen of a person taking finasteride by a pregnant woman gives rise to sufficient absorption via the intestine to cause any effect on the fetus.

Lactation: finasteride is not recommended for women during the lactation period. It is not known if finasteride is excreted in mother’s milk.

Evaluation of sexual function in patients taking Finasteride

Tosti, B.M. Piraccini, M. Soli

Department of Dermatology and Urology, University of Bologna, Italy. European Academt of Dermatology and Venereal Diseases (2001) 15, 418-421


1 mg Finasteride 1 mg (PROPECIA) has been approved in the USA and in the majority of European countries for the treatment of androgenic alopecia in its early stages in men.

The main concern that many doctors and patients have about this drug is the possible

 appearance of adverse affects that alter the sexual function, an observation that has been noted in 2% of the patients

participating in different studies performed on the drug’s effectiveness. The sexual side effects include a decrease in libido, erectile dysfunction and a reduction in the volume ejaculated.

Our practical experience, however, in a clinic specializing in hair transplants, shows that the adverse effects of a sexual nature occur in less than 0.5% of the patients that take finasteride 1 mg.

The objective of this study is to evaluate the sexual function of patients taking 1 mg finasteride compared to the control patients (without medication and of similar age) using the International Index of Erectile Function (IIEF). The IIEF is a valid means of evaluating the masculine erectile function cross-culturally as well as psychologically, which has been used to evaluate the effectiveness of sindenafil (VIAGRA) and phentolamine as oral treatments for erectile dysfunction. The IIEF is a brief questionnaire consisting of 15 questions, is reliable, performed by the patient himself, and is available in 10 languages (table 1). Five main areas are evaluated: erectile function, orgasmic function, sexual desire, satisfaction from the act of sex and satisfaction sexual in general.  The sum of the points gained in each area produce a result which when added corresponds to the final score of the IIEF, the highest score being related to a better sexual function (table 2).  The subject area is considered a worthy diagnostic tool to distinguish between patients with and without sexual dysfunction. A score of erectile function less than 25 indicates erectile dysfunction.

Method and materials

Our study includes 236 patients, between 18 and 47 years of age, who were monitored as patients with androgenic alopecia taking 1 mg finasteride. All of the patients were informed of the study, they willingly accepted to participate and they themselves answered the questions. At the time of completing the questionnaire, the average time that the patients were taking finasteride was 8 months (between 6 and 13 months). The control patients include 236 men of similar age who were attended in our hospitals for disorders of the nails. None of the control patients were taking any kind of medicine which could produce or interfere with their sexual function in any way. A statistical analysis model was used to compare the scores obtained in the questionnaires of the IIEFF in both groups of patients.

Table 1. Individual questions from the IIEF questionnaire.

Table 2. International Index of Erectile Function


The comparison between the scores obtained in the group taking finasteride and the control group did not demonstrate any statistically significant differences with respect to the general IIEF result or when taking each subject area separately (fig 1). This indicates that the sexual function as well as the erectile function of the subjects taking finasteride is not reduced with respect to the control group (patients without medication).

Figure 1. Graph which compares the erectile function (EF) and the global results of the IIEF questionnaire in patients treated with 1 mg finasteride and the control patients.


Finasteride is an inhibitor of Type II 5-alfa-reductase, inhibiting the conversion of testosterone into dihydrotestosterone (DHT). The drug is effective in the treatment of androgenic alopecia, where follicular miniaturization occurs as a consequence of the action of the androgens (especially and mainly DHT) on the follicular units.

 The administration of 1 mg finasteride (PROPECIA) significantly reduces the levels of DHT in plasma, prostate and scalp and produces a slight increase in the levels of testosterone that, however, stays within physiological limits. As it is the testosterone and not the DHT that is responsible for sexual function after puberty, then

in theory by administering Finasteride a response that leads to sexual dysfunction is not expected.

Nonetheless, the adverse effects of a sexual nature were obtained in around 2% of various clinical studies that evaluated patients taking 1 mg finasteride for androgenic alopecia. The act of informing patients about the possible interference of the drug with the sexual function can bias those results to a certain extent. The doctors who prescribe this drug rarely observe side effects of a sexual nature.

Our study was completed evaluating the sexual function of individuals taking 1 mg finasteride using an objective method, the IIEF questionnaire. In spite of the fact that the patients taking finasteride were informed of the possible adverse side effects, the results indicate that the sexual function as well as the erectile function of these patients was not reduced with respect to the control group. These results are in accordance with the experience of many dermatologists who do not observe erectile or sexual dysfunction in patients who take finasteride 1 mg.

We believe that the IIEF questionnaire should be performed routinely on patients who begin treatment with 1 mg finasteride, with the goal of being able to include a quantitative method to evaluate the sexual function during treatment. Our experience was that the questionnaire was very well accepted by the patients, who were often quite anxious about the possible side effects of a sexual nature and who were eager to have close and careful monitoring during their treatment


Folicular unit

Is all hair the same?

It is fundamental for a hair surgeon to have a complete and thorough knowledge of the anatomy and aesthetic of hair in order to be able to achieve the best results.

The form and texture of hair varies depending on its stage of evolution and position

There are several different kinds of hair:

  • The so-called lanugo is fine hair, generally fair and not pigmented which covers the foetus and which usually falls out around the eight month of gestation
  • Down hair or fuzzy hair is fine soft hair and almost invisible which can be observed in the forehead and scalp during pre-puberty
  • Terminal hair characterizes adulthood and is normally thick, long and of varied pigmentation. There are different subcategories of terminal hair and these can be found in the scalp, eyebrows, upper lip, chin, armpit, chest and pubis

Down or fuzzy hair can become terminal hair;

for example,

fuzzy hair on the face of teenagers can change into a beard.

Terminal hairs on the scalp can also turn into down hair, as is the case in male pattern baldness and female androgenic alopecia

What is a follicular unit?

When we perform a cross section cut of a hair and study it under the microscope, we observe that the hair grows in follicular units. A follicular unit (F.U.) is composed of:

  • Between one and four terminal hairs
  • One soft or down hair (rarely two)
  • Up to nine sebaceous glands
  • The pili arrector muscles
  • A perifollicular vascular plexus, and a perifollicular neural net

This suggests to a certain extent that the follicular unit constitutes a physiological entity. In a transplant, the most natural method is to insert the follicular units and therefore avoid the poor aesthetics of the old punch or mini-graft techniques, where various F.U.´s were inserted together at the same point. As well as that, and considering the aesthetics of follicular anatomy, we know that the closer we get to the frontal hair line, the less number of hairs there are in each F.U. (mono-capillary) and as we move back towards the occipital zone, the F.U.´s contain 3 and 4 hairs (for greater density).


Is everyone a candidate for a hair transplant?

Patients should have realistic expectations and should understand that, given there is currently no method for creating hair, the current techniques aim to redistribute the existing hair in as natural a way as possible. It is for this reason that

candidates are limited by a favourable donor zone

with sufficient density relative to the area to be transplanted.

Regrettably, male pattern baldness is a progressive condition. The rate of hair that is lost may diminish after reaching 40 years of age but will never completely stop.

Therefore the pre-surgical design must ensure a result that is natural looking in the long-term.

There is greater demand in patients under 30 years of age. This kind of patient with relative air loss must understand that, due to their young age, it is impossible to determine to what extent will be their hair loss. Said patient requires a more thorough evaluation to decide between the conservative medical treatment or the alternative of grafts plus medical treatment to stop hair loss and conserve existing native hair.

How much hair can we transplant?

The scalp has a surface area of approximately 500 cm2 (50.000 mm2) and an average of 200 hairs per cm2 (80 – 100 F.U.´s). As a scalp with hair has one follicular unit per mm2 and each unit has an average of 2 hairs (for example an average of two hairs per mm2)there is a total of around 100.000 hairs. This number varies of course, from patient to patient and depending on the ethnic background.

The best donor area is where there is hair that is permanently growing and which is genetically programmed to grow throughout the patient’s life,

these are the temporal and occipital regions. At the most, we can remove 50% of the hair present in the donor areas without causing these areas to appear thin or lacking in density. In theory, in the case of moderate male hair-loss patterns (type V or VI), 12.5% of the scalp is safely available to be transplanted. This is equal to 12.500 hairs or approximately 3.000 to 4.000 F.U.´s.

The appearance of fullness has much to do with the mass of the hair. This is related to the number of hairs, the thickness of the individual hairs and locks of hair, texture, colour and whether it is straight or curly. On top of that, the contrast in colour between the scalp and the hair also significantly influences the optical illusion of fullness.

Nowadays most experts agree that the average hair density in patients, who do not suffer from hair-loss, is 200 hairs per cm2

(the range goes from 130 to 280) and that only 50% of this number is required to achieve the appearance of normal density, that is 100 hairs per cm2 ( the range goes from 65 to 140). Put another way this is an average of 45 F.U.´s per cm2.