Friday, 22 October 2010

Grafting techniques in the treatment of androgenetic alopecia versus vitiligo

Androgenetic alopecia
Hair can be redistributed using autografts. This can be performed alone or in combination with reduction of the bald area by excision and closure. The implantation of artificial fibres may be complicated by foreign body reactions and infection and its use has been banned.

On the scalp, and some other regions of the skin, hair follicles are arranged in groups of follicles known as follicular units. Each follicular unit is supplied by a single arrector muscle, which splits to encircle each follicle within the follicular unit.

Follicular Unit Extraction (FUE) is a hair transplant method that involves removing one follicular donor unit (one follicular unit contains some 3 hairs, sometimes emerging from single follicular opening) at a time from the back or sides of the scalp or occasionally from the body (body hair FUE) and placing it into the bald or thinning recipient area of the scalp. A punch with 0.75 mm diameter is used to extract one follicular unit from the donor area. The patient’s natural follicular units in the donor area are first identified; these are then removed from the surrounding skin and then placed in the recipient area taking into consideration some factors like the appropriate density and orientation. These ‘minigrafts’, are manipulated to produce a natural-looking frontal hairline. Maintaining hair follicle unit groupings enhances graft survival too. FUE leaves less noticeable postoperative scarring in the donor area.




There are manual FUE and powered FUE (P-FUE). In P-FUE (preferred method), the speed of the punch blade rotation is usually 700 to 1,500 rpm. The punch blade penetrates the epidermis and dermis and rotation should be stopped when the punch blade reaches the subcutaneous tissue. At this point, the operator senses a loss of resistance. Over-penetration causes hair transection as the punch fails to follow the angle of the hair.  The graft is then implanted using a pneumatic implanter or forceps. The P-FUE method can be considered to be superior to the conventional manual FUE method in terms of speed and transection rate. With the P-FUE procedure, a 0.8 - 1.0-mm punch blade is generally used, but harvesting is occasionally impossible unless performed with a 1.25-mm punch blade. A new system (NeoGraft Automated FUE hair transplant system) has been developed that harvests, collects, and implants individual follicular grafts using one user-friendly platform. 


FUE can be used alone or can be combined with removing a strip containing a large number of follicular units from the donor area (follicular units are then dissected under microscopes equipped with fibre optics to avoid the application of heat to the follicles).
If FUE is performed long before the ultimate pattern of hair loss is clear and without adjunctive medical therapy to prevent progression of the balding process, an unnatural appearance can evolve over time that may require further surgery to correct.



·  Hair Stem CellTransplantation (HST), also called partial longitudinal FUE*. One of the most significant differences with traditional techniques is that with HST only a tiny part of the hair follicle is removed. The majority of the follicle is left it in the donor area where it will produce new hair. This preserves the donor area for future treatments, which is why this technique should actually be referred to as hair multiplication, rather than transplantation. In case of partial longitudinal FUE, where follicular stem cells remain at the donor site as well as in the partial extracted follicle, a donor site capable of multiple hair transplantations should become possible. Extraction of the partial longitudinalfollicular units (grafts): Grafts are harvested with hollow triple-waved-tipped, partially blunt needles with an inner diameter of 0.6 mm (Hair Science Institute, Amsterdam, The Netherlands). To extract a partial longitudinal follicular unit, the hair shafts are used as guidance for the needle. This enables extraction of a partially longitudinal follicular unit. The aim of the extraction is to remove only a part of the follicle unit, containing follicle and connective tissue, and leave sufficient follicle unit tissue behind to regenerate hairs. The clinical results concerning the re-growth of partial hair follicles are not in correlation with other clinical studies that recommended not implanting sectioned hair follicle parts.


Vitiligo

Surgical treatments are reserved for cosmetically sensitive sites (results are less good in the extremities and around orifices) in patients in whom there have been no new lesions, no Koebner phenomenon and no extension of the lesion in the previous 12 months.

Autologous epidermal cell suspension containing basal keratinocytes and melanocytes [the dermis of a split-thickness skin graft is separated from the epidermis, and the dermal side of the epidermal layer is manipulated using a blunt forceps to release cells from the basal layer of the epidermis into a solution of normal saline and a suspension is prepared following centrifugation] applied to laser-abraded lesions (transplanting functional melanocytes to the depigmented area after preparation of the affected area with laser peeling of the skin) followed by phototherapy is the optimal transplantation procedure but requires special facilities. Expanding the autologous cells in tissue culture prior to grafting is feasible and can treat larger areas successfully, without the need for additional phototherapy. However, the culturing introduces growth factors leading to uncertain risks and cultures can fail, reducing the value of the procedure.

Split-skin grafting gives much better cosmetic and repigmentation results than minigraft procedures and actually minigraft procedure is NOT recommended due to a high incidence of side-effects (partial take, thick margins and milia) and poor cosmetic results including cobblestone appearance and polka dot appearance (poor colour match). Epidermal blister grafting (transfer of suction blisters) is an alternative transplantation method, which shows evidence of benefit over placebo but gives less good coverage than split-skin grafting or epidermal suspension applied to laser-abraded lesions.



Practically, split-skin grafting is the best option when a surgical treatment is required.


*Gho C.G. and H.A. Martino Neumann. Donor hair follicle preservation by partial follicular unit extraction. A method to optimize hair transplantation. J Dermatolog Treat 2010. 21(6): p. 337-49. 


This page was lasted updated in February 2014.


 

1 comment:

  1. 1) The acquisition of basic skin surgery skills is an important component of dermatological training but there is no doubt that certain aesthetic procedures are best done by aesthetic plastic surgeons not only because they are fully trained plastic surgeons who have undergone a rigorous training programme but also they can combine surgical techniques (some of which are clearly beyond the scope of dermatology), as in the example shown above, in the best interests of the patient. "I do not like the cosmeticisation of dermatology - not what I did medicine to do," said Professor Rona MacKie, FRCP, when asked about the dangers to the field of dermatology.

    2) The physician specialty of "dermato-venereology" embraces dermatology (skin health) and venereology (male and female sexual health). The reasons behind the combination are that a number of patients with sexually transmitted infections may first present to the dermatologist and a number of patients with skin conditions may first present to the venereologist. In the UK surgical andrology (surgical aspects of male health) is part of the surgical specialty of urology (uro-andrology) and venereology (also called genitourinary medicine) is separate from dermatology. There are some areas of overlap between dermato-venereology and other specialties such as gynaecology, uro-andrology, aesthetic plastic surgery, general surgery and endocrinology.

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Main Works of Reference List (The first eight are my top favourites)

  • British National Formulary
  • British National Formulary for Children
  • Guidelines (BAD - BASHH - BHIVA - Uroweb)
  • Oxford Handbook of Genitourinary Medicine, HIV, and Sexual Health
  • Oxford Handbook of Medical Dermatology
  • Rook's Textbook of Dermatology
  • Simple Skin Surgery
  • Weedon's Skin Pathology
  • A Concise Atlas of Dermatopathology (P Mckee)
  • Ackerman's Resolving Quandaries in Dermatology, Pathology and Dermatopathology
  • Andrews' Diseases of the Skin
  • Andrology (Nieschlag E FRCP, Behre M and Nieschlag S)
  • Bailey and Love's Short Practice of Surgery
  • Davidson's Essentials of Medicine
  • Davidson's Principles and Practice of Medicine
  • Fitzpatrick's Colour Atlas and Synopsis of Clinical Dermatology (Klaus Wolff FRCP and Richard Allen Johnson)
  • Fitzpatrick’s Dermatology in General Medicine
  • Ganong's Review of Medical Physiology
  • Gray's Anatomy
  • Hamilton Bailey's Demonstrations of Physical Signs in Clinical Surgery
  • Hutchison's Clinical Methods
  • Lever's Histopathology of the Skin
  • Lever's Histopathology of the Skin (Atlas and Synopsis)
  • Macleod's Clinical Examination
  • Martindale: The Complete Drug Reference
  • Oxford Handbook of Clinical Examination and Practical Skills
  • Oxford Textbook of Medicine
  • Practical Dermatopathology (R Rapini)
  • Sexually Transmitted Diseases (Holmes K et al)
  • Statistics in Clinical Practice (D Coggon FRCP)
  • Stockley's Drug Interactions
  • Treatment of Skin Disease: Comprehensive Therapeutic Strategies
  • Yen & Jaffe's Reproductive Endocrinology