WO2005077285A1

WO2005077285A1 - Hair harvesting instrument, needle assembly, use of said instrument, hair harvesting method and hair transplantation method

Info

Publication number: WO2005077285A1
Application number: PCT/NL2004/000113
Authority: WO
Inventors: Conradus Ghosal Gho
Original assignee: Gho Holding B.V.
Priority date: 2004-02-16
Filing date: 2004-02-16
Publication date: 2005-08-25

Abstract

The present invention relates to a hair harvesting instrument (30) for use in harvesting hairs to be transplanted, said instrument comprising a hollow harvesting needle (31) having an internal diameter smaller than 1 mm; a marker (32) for marking an insertion length IL of the harvesting needle, the insertion length IL being defined, in longitudinal direction of the harvesting needle, between the distal tip (38) of the harvesting needle and the marker, wherein the hairs to be transplanted have a predetermined hair follicle length HFL, and wherein IL ≤ ¾ HFL such as IL ≤ 0.7 HFL. The invention also relates to an assembly comprising a hollow harvesting needle and a hollow implanting needle.

Description

Hair harvesting instrument, needle assembly, use of said instrument, hair harvesting method and hair transplantation method.

Background of the invention

Technical field

The present invention relates to a method for harvesting hairs to be transplanted, method for hair-transplantation and to devices that are used in said methods.

Prior art

The known phenomenon of pattern baldness has provided improvements of techniques for transplanting hair follicles from one area of the scalp region to another area of the scalp region where hair follicles are no longer active. Typically, hair is harvested from the back side of the scalp to create hair grafts that are subsequently implanted in the front side of the scalp or another region where hair growth is desired such as the top and crown of the head. A wide variety of devices and methods directed to graft harvesting and placement techniques are disclosed in the prior art, including the disclosures of US 6.585.746, US 6.399.057, US 6.059.807, US 5.984.936, US 5.585.019, US 5.827.297, US 5.693.064, US 5.662.661, US 5.643.308, US 5.611.811, US 5.611.810, US 5.584.851, US 5.584.841, US 5.578.054 US 5.562.732, US 5.490.850, US 5.439.475, US 5.417.683, US 5.273.900 and US 4.243.038, the entire contents of which being incorporated herein by reference. Although there have been several advances made in recent years with regards to increasing the density of transplanted follicles and the aesthetic appeal of the configurations employed, patients undergoing hair restoration procedures may still be disappointed for several reasons including poor graft growth. Poor graft growth is an unpredictable complication of hair transplant surgery and has been reported with every technique ever employed including minigrafts and micrografts. Micrografts may contain one to two hair follicles whereas minigrafts may contain from three to five hair follicles. The complication of poor graft growth is the least understood complication of this type of surgery and occurs even with the most meticulous technique in the hands of skilled surgeons. A critical aspect of successful transplant surgery is the quality of the grafts produced. Quality is dependent on several factors including hair characteristics, hair density and the technique by which the grafts are produced. Of these, the characteristics and density are variables beyond the control of the surgeon. Thus the key factor in performing a successful hair transplant is the graft production technique. As described in general terms above, the hair transplantation technique generally requires removal of an elliptical-shaped flap of scalp from the back side of the patient's scalp. The micrografts and/or minigrafts may be removed from the flap of the patient's scalp that has been removed. The incision made to remove the flap is stitched together, and normally leaves a well-concealed scar. The new grafts are then inserted in very small openings formed in the patient's scalp where it is desired to have the grafts implanted. Usually, the grafts are implanted about 1.5 mm from each other into the bald area of the patient's scalp to be treated. Generally, the very small openings that are formed in the patient's scalp to receive the grafts, heal very well, normally without leaving any scars. However, the prior art techniques suffer from several important disadvantages in that they involve laborious, tedious and uneconomical procedures, hi addition, these techniques must completely be carried out by highly skilled personal, i.e. surgeons. Furthermore, hair growth of the transplanted micrografts and or minigrafts is often poor. Additionally, another important drawback of some prior art methods is that the grafts taken from donor regions include the skin with the result that the donor region is completely depleted from hair. Finally, the devices employed in the prior art methods are unsuitable to carry out the prior art hair transplantation techniques in an efficiently manner as will be apparent below. The present invention provides therefore an instrument and method for harvesting hairs, called grafts, to be transplanted as well as a method for hair-transplantation that constitute an improvement over prior art methods in terms of labour and economics. For example, according to the present invention only a minor part of the procedures for hair transplantation needs to be performed by highly skilled personnel such as surgeons whereas the major part of the said procedures, amongst which the harvesting, can be carried out by personnel of lower skill, e.g. nurses. Moreover, the methods according to the present invention provides induction of hair growth by transplantation of partial follicular units which is the result of an improved harvesting technique, i.e. that at the donor regions hair growth is still possible after removal of the grafts. Finally, the present invention provides devices that enable an efficient and efficacious performance of the methods of the present invention.

Summary of the invention

The present invention provides a hair harvesting instrument for use in harvesting hairs to be transplanted, said instrument comprising: • a hollow harvesting needle having an internal diameter smaller than 1 mm; • a marker for marking an insertion lengt IL of the harvesting needle, the insertion length IL being defined, in longitudinal direction of the harvesting needle, between the distal tip of the harvesting needle and the marker; • wherein the hairs to be transplanted have a predetermined hair follicle length HFL, and wherein IL < ³Λ HFL. IL may according to an additional feature of the invention be Vi HFL, such as about % HFL, 0.6 HFL or 0.7 HHL.

Thus, IL may lie in the range of A HFL, % HFL], such as in the range of [0.6 HFL, 0.7

HFL] or [Vi HFL, 0.7 HFL] or [0.6 HFL, ³Λ HFL] or another range in between ^l HFL and ³Λ HFL.

Although longer donor hair follicle lengthes do occur, about 80 % of the donor hair follicles will in practise be < 6 mm. Practically, donor hair follicles will have a length between 5 and 6 mm. The insertion length of the harvesting needle will, according to an additional feature of the invention, generally be smaller than or equal to 4.5 mm, such as smaller than or equal to 4 mm. Further, the insertion length of the harvesting needle will preferably be longer than 3 mm in order to assure a graft which will likely be successful. According to a further additional feature of the invention the marker is provided on the harvesting needle and/or surrounds the harvesting needle. The marker may be visible and/or tangible in order to assist the person using the instrument to see or feel when the needle is inserted the insertion length into the skin of the patient. The marker can additionally or alternatively also be a stop preventing deeper insertion of the harvesting needle into the skin. A marker, which is reliable in it's use and that can easily be adjusted for the correct insertion depth prior to harvesting, is provided in case one uses a shrink sleeve around the harvesting needle. This shrink sleeve is a movable along the needle for adjustment in the correct position and is than fixed to the needle by heating it so that it shrinks onto the needle. The harvesting needle will preferably have an internal diameter of < 0.75 mm, such as ≤ 0.5 mm. The outer diameter of the harvesting needle will preferably be 1 mm. In order to insert the harvesting needle easily without undue damaging of the donor hair follicle or the graft, it is advantageous that the instrument comprises a drive for giving a rotary movement to the needle. In this respect a rotary movement appears to be preferred as it assist the person using the instrument to keep it steady. In order to cut through the donor hair follicle at the desired insertion depth, it is preferred that the cutting edge is - straight or curved - levelled with respect to the longitudinal axis of the harvesting needle and has a most distal tip, and wherein the cutting instrument comprises a distal tip indicator arranged at least IL proximal of the most distal tip to indicate the side of the harvesting needle carrying the most distal tip. This enables the person using the instrument to tilt the harvesting needle so that the most distal tip moves into the cross-section region defined by the cylindrical contour of the harvesting needle. In order to enable the person using the instrument to adjust the marker in dependence of the length of the donor hair follicles, it is advantageous to have an adjustable marker. The present invention further provides an assembly of hollow harvesting needles for use in an instrument according to the invention, each harvesting needle being provided with a marker. This enables the person using the instrument according to the invention to choose a needle with a proper insertion depth without having to perform an adjusting procedure. The present invention further provides an assembly of a harvesting needle and an implanting needle, both needles having essentially the same features and diameters. This results in a perfect fit of the graft in the receptor region, increasing the likelihood that the graft will be successful. The present invention further provides a method, preferably a cosmetic method, for harvesting hairs to be transplanted, wherein one or more hair follicle grafts are harvested from the respective donor hair follicles, the grafts having a length shorter than the length of the respective donor hair follicles and comprising the upper part of the donor hair follicles, and wherein the lower part of the respective donor hair follicles are left behind in the respective donor hair follicles. Preferably the upper part of the donor hair follicles comprises the upper stem cell pool, whilst the lower part of the donor hair follicles preferably comprises the lower stem cell pool. Thus, preferred, the present invention provides a harvesting method for harvesting hairs to be transplanted, wherein one harvests one or more hair follicle grafts from respective donor hair follicles, the grafts having a length shorter than the length of the respective donor hair follicles and comprising the upper stem cell pool of the respective donor hair follicles, and wherein the lower stem cell pool of the respective donor hair follicles are left behind in the respective donor hair follicles. Preceding the actual harvesting, the method preferably comprises selecting one or more hair follicle donor regions comprising donor hair follicles suitable for providing one or more hair follicle grafts. Advantageously, the length of the graft will be ≤ % of the length of the donor hair follicle to ensure that a great part of the hair follicle donor region will develop new hair follicles. In order to ensure sufficient success of the implanted grafts, it is advantageously when the graft is > ^lA of the length of the donor hair follicle. In order to ensure on the one hand a good development of new hair follicles at the donor region and on the other hand a high rate of success for the implanted grafts in the receptor region, it is according to the invention advantageous when the length of the graft is about ²/3 of the length of the donor hair follicle. According to present insight of the inventor, the length of the graft will, in about 80 % of the cases, be > 3 mm and < 4.5 mm. The method according to the invention further provides hair multiplication at the receptor region. It appears that a hair follicle graft comprising one hair fibre multiplies itself in the receptor region in the sense that more than one hair fibre grows out of the graft (which originally had only one fibre). This phenomenon, called pili multigemini or hair multiplication, is not yet fully understood, but the inventor believes it could be explained by small damages in the upper stem cell pool. The method according to the invention therefore, comprises optionally as a further step providing cuts in the upper part of the hair follicle, especially in the region of the upper stem cell pool. Those cuts result in multiplication of hair fibres. These cuts can be provided during harvesting, but also after harvesting before implanting. The present invention further provides a (cosmetic) method, preferably a cosmetic method, for hair-transplantation (and preferably also hair-multiplication) comprising the following steps:

(a) selecting a hair follicle donor region suitable for providing one or more hair follicle grafts;

(b) harvesting from a said hair follicle donor region one or more hair follicle grafts with the harvesting method according to the present invention;

(c) selecting a graft receptor region to receive one or more hair follicle grafts;

(d) forming a plurality of small openings in the graft receptor region; and (e) implanting into said plurality of small openings said hair follicle grafts.

According to an additional feature of the invention one will use in step (b) a hollow harvesting needle and or in step (e) a hollow implantating needle, which are advantageously the same needles or advantageously have about the same diameters.

Brief description of drawings

In the drawings: Fig. 1 A shows schematically, in cross section an intact donor hair follicle; Fig. IB shows schematically, in cross section a donor hair follicle after a graft has been taken away; Fig. 2 shows schematically, in cross section a first embodiment of an instrument according to the invention; Fig. 3 shows schematically, in cross section a second embodiment of an instrument according to the invention; Fig. 4 shows schematically, in cross section an assembly according to the invention comprising a harvesting needle and an implanting needle; and Fig. 5 shows schematically, in cross section an assembly according to the invention, comprising a number of harvesting needles. Fig. 6 shows schematically in perspective view a third embodiment of an instrument according to the invention; and Fig. 7 shows schematically in cross section the anatomy of an hair follicle. Detailed description of the invention

With reference to fig. 1 A and B:

• in this description, a "hair follicle graft" or "graft" 7 is defined as that part of the hair that is removed in the harvesting step.

• in this description, a "donor hair follicle" 3 is defined as the hair from which the graft 7 is taken, thus in case the taken "hair follicle graft" 7 does not comprise the entire "donor hair follicle" 3 there is a remaining part 8 of said "donor hair follicle" 3 still called the "donor hair follicle" 3. The present invention is based on the surprising discovery that both the upper part and the lower part of hair follicles comprise regions comprising stem cells that are capable to proliferate into hair follicle cells. Those regions will be called the upper 5 and lower 4 stem cell pool. As a consequence, if only the upper part of the donor hair follicle is harvested and transplanted into the small openings in the hair follicle receptor region, hair fibres 2 will eventually not only grow in the hair follicle receptor regions, but also in the hair follicle donor regions. As will be apparent to the person skilled in the art, this feature of the invention - providing so to say a 'hair multiplication effect' - constitutes a significant improvement over the prior art methods. Harvesting may be carried out by using a cylindrical hollow harvesting needle having an inside diameter that is slightly larger that the diameter of the hair fibre. Such needle devices are well known in the art. Reference is made to e.g. US 5.827.297, incorporated by reference herein. However, it is preferred that the cylindrical hollow harvesting needle is provided with a marker to ensure that the person operating the harvesting needle will stop inserting the harvesting needle at a pre-adjusted depth. This marker can be adapted to prevent any insertion deeper than the pre-adjusted depth. The needle device is moved over the donor hair follicle, which are usually occurring in the dermis as groups of three, whereafter the needle device is inserted into the skin, preferably when rotating, to cut (part of) the donor hair follicle loose from the tissue surrounding donor hair follicle. Then the graft can be taken out by pulling. In case the cross section of the donor hair follicle has not been (fully) cut through, breaking of the donor hair follicle will be caused by the pulling at a location between the two regions comprising stem cells, hi order to improve the quality of the graft it is advantageous to cut through the cross section of the donor hair follicle, for example by manipulating, such as slightly tilting, the harvesting needle. Generally, only one hair fibre breaks off whereas the other two remain unaffected. According to the invention, the same or same kind of needle is used for the harvesting step (b) and the implanting step (e). This has the advantage that the small openings in the hair follicle receptor region heal very quickly, i.e. usually within one single day. According to the invention, it is essential that that part of the hair fibre that constitutes about 50% to about 75% (that corresponds to ^lA ≤IL <%) of the length of the hair fibre, calculated from the top of the hair fibre, is removed. In this way the upper part of the hair follicle including the upper growing nucleus comprising stem cells is removed and used for the transplant process thereby enabling the induction of the growth of hair fibres in a hair follicle receptor region. The remaining part of the hair follicle including the lower growing nucleus comprising stem cells remains in the hair follicle donor region thereby enabling the growth of hair fibres at said hair follicle donor region. It appeared that about 30 to about 80% of the hair follicles remaining in the donor regions showed growth of hair fibres. It further appeared that after seven days significant hair growth occurred at the hair follicle receptor regions and that a head of hair was formed within fourteen days. Hair follicles are located in the dermis and occur usually at a depth of about 5 to about 6 mm, calculated from the surface of the epidermis. However, the depth at which the hair follicles are located may vary from location to location of the hair follicle donor region and from patient to patient. To ensure that the number of hair follicle grafts having the correct length is as high as possible, it is preferred that the surgeon first harvests a few samples to determine the correct depth at which the needle device must be inserted. According to the invention it is preferred that the harvested hair follicle grafts are first collected, e.g. in a petri dish or other suitable container or vessel comprising a medium for preserving the grafts, whereafter part of the harvested grafts are selected for the implanting step. Hence, according to a preferred embodiment of the invention, the hair follicle grafts harvested in step (b) are subjected to a selection step prior to implanting step (e). According to a preferred embodiment of the invention, the patient subjected to the method of the invention is first anaesthetised, preferably by employing an anaesthetising device (cf. WO 03/0/45481, incorporated by reference herein). Fig. 1 A shows a donor hair follicle before a graft is taken. 1 indicates the skin, 2 indicates a hair fibre. 3 indicates the so called 'donor hair follicle', 4 indicates the lower growth nucleus comprising stem cells and HFL indicates the hair follicle length. Fig. IB shows a donor hair follicle 3 after a graft 7 has been taken away. After the graft 7 has been cut loose - to be described below - it can be taken out of the donor hair follicle, for example by means of a pair of tweezers. The upper part of the hair follicle forming part of the graft 7 is surrounded by some tissue 6. The part of the donor hair follicle 3 left behind in the skin of the patient, is indicated with 8. It is to be noted that according to the invention the skin 1 of the patient from which the graft is taken, can, prior to harvesting the graft, be removed as a flap from the scalp of the patient. After harvesting this flap can be placed back on the scalp of the patient at a different place or at the place where it originates from. It is according to the invention however preferred, that the hairs are harvested directly from the patients scalp. As such a single harvesting procedure is not very painful for the patient. As in practise easily more than hundred grafts will be taken, anaesthesia of the patient will be preferred. Fig. 2 shows schematically a first embodiment of an instrument according to the invention. This instrument 30 comprises a cylindrical hollow needle 31 and a slidable sleeve 32 of a plastic, such as silicon. The sleeve 32 is fixed on the needle 31 by a frictional clamping which allows the sleeve 32 being slidable for adjusting the insertion length IL. As an example of an alternative, the sleeve 32 could be made of an heat shrinkable plastic, which allows, when adjusted into the correct IL position, the sleeve being fixed on the needle 31 by heat shrinking.. The instrument 30 further comprises a drive 33 for reciprocating movement (arrow 35) of the needle 31 around its longitudinal axis. Reference numbers concerning the donor hair follicle are identical to the one used in fig. 1A and IB. The sleeve 32, especially its lower edge functions as a marker marking the insertion length IL of the needle. As soon as the needle 31 has been inserted a distance IL into the skin the person operating the needle will feel a stop onto the skin when the lower edge of the sleeve 32 touches the skin. This step prevents the needle from being inserted further into the skin. The distal end 38 of the needle is formed as a cutting edge will be halted above the lower growing nucleus 4. At the level of the cutting edge 38 the donor hair follicle can be cut through in crosswise direction by tilting the needle slightly as indicated by arrow 36. Fig. 3 shows a second embodiment of an instrument 40 according to the invention. Reference numbers concerning the instrument 40, as far as the parts correspond to the parts in fig. 2, indicated with the same number increased with ten. The difference between fig. 3 and fig. 2 is essentially that in fig. 3:

• the cutting edge 48 is levelled to have a most distal tip 44;

• the marker 42 is a visual marker comprising a line 42 formed around the needle; and • an indicator 47 is provided on the needle, to indicate the side of the needle where the most distal tip 44 is provided.

It will be clear that the visual marker 42 can also be applied in the fig. 2 embodiment without applying the other differences. The slanting cutting edge 48 together with the tip position indicator 47 enables the operator of the needle to tilt the needle slightly according to arrow 46, so that the tip portion 44 is used for cutting through the cross section of the donor hair follicle. Fig. 4 shows schematically an assembly according to the invention comprising a harvesting needle 50 and an implanting needle 60. The harvesting needle has an internal diameter 'intDhn', an external diameter 'exDhn', and a wall thickness X. The implanting needle has an internal diameter 'intDin', an external diameter 'exDin' and a wall thickness 4. For a perfect fit of the graft in the donor region, the 'intDin' will, at least approximately, be equal to 'intDhn', while the wall thickness y is small, preferably at most 0.1 mm. For practical reasons X will be about y and 'exDhn' will be about 'exDin'. Fig. 5 shows schematically an assembly of, in this example, four harvesting instruments/harvesting needles provided with marker according to the invention. The harvesting needles 71 are essentially identical. The markers 72, 73, 74, 75 in the form of sleeves are however arranged at a different IL. For example sleeve 72 marks an IL of 3 mm, sleeve 73 an IL of 3.5 mm, sleeve 74 an IL of 4 mm and sleeve 75 an IL of 4.5 mm. Such an assembly enables the operator to pick the marked needle having an IL in correspondence with an IL determined for example by taking a sample graft comprising a complete, intact 'donor hair follicle'. In this situation the operator does not have to perform an adjustment procedure for adjusting the marker at an appropriate IL. Fig.6 shows a distal part of a third embodiment of an instrument according to the invention. In this embodiment the distal end 8 of the needle 80 is toothed, h this example only two teeth 87 are provided. In circumferential direction of the needle, the distal edge is shaped as a cutting edge 86. The advantage of the teeth is that it functions as the serrations of a serrated knife when the needle is rotated or rotated to and from around its longitudinal axis. Fig. 7 shows the anatomy of a hair follicle, schematically but more detailed than in the other figures. In case one would use an adjustable marker, the appropriate IL can be deteimined in a similar manner. In fig. 7, 100 indicates epidermis, 101 indicates dermis and 102 indicates the so called dermal papilla. 103 indicates the skin of the patient. Inventor found that at about 1/3 of the depth L an upper region of stem cell pools 104, called the upper stem cell pool, is present, and that those upper stem cell pool results in an entire new hair follicle if one transplants only the upper part of the hair follicle instead of the entire hair follicle with length L. The inventor further found that also at the lower end of the hair follicle a lower region of stem cells 105 is present, called the lower stem cell pool. The distance of the lower stem cell pool to the lower end of the follicle is about 10 - 20% or more of the length L. So in case L is about 10 mm, L. is roughly about 3 mm and L₂ is roughly about 1-2 mm or larger. The preceding locations of the stem cell pools are indicative as further investigation is to be carried out for a more exact determination of the location. Inventor was able to determine stem cell pools by use of markers. One usable marker is the well known marker for anti-apoptosis BCL-2. This because stem cells have to be protected against apoptosis (which is programmed cell death). Another usable marker is CK-19, which stains specific follicular stem cells.

Claims

1) A hair harvesting instrument for use in harvesting hairs to be transplanted, said instrument comprising: • a hollow harvesting needle having an internal diameter smaller than 1 mm; • a marker for marking an insertion length IL of the harvesting needle, the insertion length IL being defined, in longitudinal direction of the harvesting needle, between the distal tip of the harvesting needle and the marker; wherein the hairs to be transplanted have a predetermined hair follicle length HFL, and wherein IL < ³/ HFL such as IL 0.7 HFL.

2) Hair harvesting instrument according to Claim 1, wherein IL ≥ ^lA HFL, such as LL < 0.6 HFL.

3) Hair harvesting instrument according to one of the preceding Claims, wherein IL is about ²/₃ HFL.

4) Hair harvesting instrument according to one of the preceding Claims, wherein HFL ≤ 6 mm.

5) Hair harvesting instrument according to one of the preceding Claims, wherein 5 mm < HFL < 6 mm.

6) Hair harvesting instrument according to one of the preceding Claims, wherein 3 mm ≤ IL ≤ 4.5 mm.

7) Hair harvestmg instrument according to one of the preceding Claims, wherein IL <4 mm.

8) Hair harvesting instrument according to one of the preceding Claims, wherein the marker is provided on the harvesting needle. 9) Hair harvesting instrument according to one of the preceding Claims, wherein the marker surrounds the harvesting needle.

10) Hair harvesting instrument according to Claim 9, wherein the marker is a shrink sleeve.

11) Hair harvesting instrument according to one of the preceding Claims, wherein the harvesting needle has an internal diameter ≤ 0.75 mm, such as 0.5 mm.

12) Hair harvesting instrument according to one of the preceding Claims, further comprising a drive for providing the harvesting needle a rotary movement around it's longitudinal axis.

13) Hair harvesting instrument according to Claim 12, wherein the rotary movement is a reciprocating rotary movement.

14) Hair harvesting instrument according to one of the preceding Claims, wherein the distal end of the harvesting needle is provided with a cutting edge.

15) Hair harvesting instrument according to Claim 14 in combination with at least Claim 13, wherein the cutting edge is bevelled with respect to the longitudinal axis of the harvesting needle and has a most distal tip, and wherein the cutting instrument comprises a distal tip indicator arranged at least IL proximal of the most distal tip to indicate the side of the harvesting needle carrying the most distal tip.

16) Hair harvesting instrument according to one of the preceding claims, wherein the distal end of the needle is toothed.

17) Hair harvesting instrument according to one of the preceding Claims, wherein the marker is adjustable. 18) Assembly comprising a set of hollow harvesting needles each provided with a marker for use in an instrument according to one of the Claims 1-16, wherein the markers are fixed on the needles at different IL.

19) Assembly comprising: • a hollow harvesting needle, such as an instrument according to one of the Claims 1-17 or a harvesting needle of an instrument according to one of the Claims 1-17; and • a hollow implanting needle; wherein the internal diameter of the harvesting needle is about the same as the internal diameter of the implanting needle (intDin); and wherein for the external diameter of the implanting needle (exDin) applies: exDin - intDin < 0.2 mm.

20) Use of a hair harvesting instrument according to one of the Claims 1-17 for harvesting hairs to be transplanted.

21) A harvesting method for harvesting hairs to be transplanted, wherein one harvests one or more hair follicle grafts from respective donor hair follicles, the grafts having a length shorter than the length of the respective donor hair follicles and comprising the upper part of the respective donor hair follicles, and wherein the lower part of the respective donor hair follicles are left behind in the respective donor hair follicles.

22) Harvesting method according to claim 21, wherein, before harvesting, one or more hair follicle donor regions comprising donor hair follicles suitable for providing one or more hair follicle grafts are selected.

23) Harvesting method according to one of Claims 21-23, wherein the length of the graft is < % of the length of the donor hair follicle (HFL).

24) Harvesting method according to one of Claims 21-23, wherein the length of the graft is > Vz of the length of the donor hair follicle. 25) Harvesting method according to one of Claims 21-24, wherein the length of the graft is about ²A of the length of the donor hair follicle.

26) Harvesting method according to one of Claims 21-25, wherein the length of the graft is ≥ 3 mm and <4.5 mm.

27) Harvesting method according to one of Claims 21-26, wherein one uses an instrument according to one of the Claims 1-16.

28) A cosmetic hair-transplantation method for hair transplantation and hair- multiplication comprising the following steps: (a) selecting a hair follicle donor region suitable for providing one or more hair follicle grafts; (b) harvesting from a said hair follicle donor region one or more hair follicle grafts with the harvesting method according to one of Claims 20-27; (c) selecting a graft receptor region to receive one or more hair follicle grafts; (d) forming a plurality of small openings in the graft receptor region; and (e) implanting into said plurality of small openings said hair follicle grafts.

29) Method according to claim 28, wherein step (b) is carried out by using a cylindrical hollow harvesting needle.

30) Method according to one of Claim 28-29, wherein step (e) is carried out by using a cylindrical hollow implantation needle.

31) Method according to one of Claims 28-30, wherein step (b) and step (e) are carried out with the same cylindrical hollow needle.

32) Method according to one of Claims 28-31, wherein steps (b) and (e) are carried out by using a hollow harvesting needle and the implantation needle, respectively, the implantation and the harvesting needle having about the same diameter dimensions. 33) Method according to one of Claims 28-32, wherein steps (b) and (e) are carried out by using a hollow harvesting needle and the implantation needle, respectively, wherein the internal diameter of the harvesting needle is about the same as the internal diameter of the implanting needle (intDin); and wherein for the external diameter of the implanting needle (exDin) applies: exDin- intDin <0.4 mm.

34) Method according to one of Claims 28-33, wherein the harvesting needle is provided with a depth adjusting means.

35) Method according to one Claims 27-34, wherein the harvested hair follicle grafts harvested in step (b) are subjected to a selection step prior to implanting step (e).