Perspectives of surgical treatment of vitiligo

Summary

The absence of causal and poor results of conservative treatment of vitiligo in many cases leads to a search for different treatment possibilities such as surgical treatment. All techniques of surgical treatment of vitiligo are based on autologous melanocytes grafting into the achromatic skin leasions. There are some dissimilarities between various surgical methods, the dissimilarities are in preparation of recipient skin site, in harvesting and processing of autologous melanocytes before their grafting. The surgical treatment is useful for patients with stabile achromatic skin lesions up to 30% of total body surface area in cases in which medical treatment has failed. This article is a rewiev of different surgical techniques in surgical treatment of vitiligo.

Key words.
Vitiligo, surgical treatment of vitiligo, review of surgical treatment of vitiligo

Vitiligo belongs to many other idiopathic diseases with no causal treatment today. The effort to treat vitiligo with surgical treatment is a logical ending when looking at the poor results of medical treatment of many patients. The aim of surgical treatment is repigmentation of depigmented skin leasons. All techniques of surgical treatment are based on autologous melanocytes grafting into the affected skin leasons. There are some dissimilarities between various surgical methods. The dissimilarities are in preparing of recipient skin site, in harvesting and processing of autologous melanocytes before their grafting. With the number of surgical treatet patients and experiences with surgical treatment there are selection criteria for surgical treatment(1,2). The following are the criteria for the selection of cases for surgery:

1. Patients refractory to medical treatment
2. Patients with stable vitiligo for more than 1 year, with depigmented skin at maximum of 30% of total body surface area
3. Patients with no history of hypertrophic or keloid healing
4. Patients with positive minigraft test (3,4)
5. Patients without the Koebner phenomenon
6. Patients older than 12 years

Many various surgical techniques and modifications of surgical treatment of vitiligo have been published. Currently available surgical treatments can be divided mainly into two categories: I. techniques without cells separation after pigmented skin harvesting (skin is transplanted in different thickness) and II. techniques that involve separation of skin cells.

I. Techniques without skin cells separation – skin tissue grafts

1) split-thickness skin grafts

Split-thickness skin grafting involves the free transfer of the epidermis along with a portion of the dermis in 0,1-0,2mm thick. The graft is harvested with a motorized dermatome. The recipient area must be denuded of epidermis by dermabrasion or laser abrasion. This method is recommended to patients with the achromatic skin up to 150cm2. The complications of this method are light-coloured treated skin usually caused by a low number of melanocytes in grafted skin and postinflammatory hypo or hyperpigmentation of the donor site.(2)

2) punch grafting

It is a grafting of full-thickness pigmented skin grafts 3mm in diameter harvested with the tool for punch biopsies. These grafts are implanted into pits in the recipient area with an equal or 0,5mm smaller diameter than the actual diameter of skin grafts. The recipient holes are created mechanically and should be placed 4-8 mm apart from each other(1). There can be a complication to this method which is the cobblestone effect in 27-32% of patients (1,2). This complication can be eliminated by creating a hole in the recipient area about 1mm deeper than the thickness of the skin graft(5), or by using a silicon sheet as covering during the postoperative period(6).

3) mini punch grafting

This is the same technique as punch grafting, the difference is in the diameter of grafted skin, which is 1,5-2,5mm thick and the thickness of grafts is 0,6-0,8mm. The holes in the recipient area are also created mechanically or by Erbium-YAG laser(7). It is very difficult to achieve the immobilization of grafts in areas such as lips, areola etc. Tissue glue can be quite helpful in such cases(8).

4) suction blister grafting

This method was published by Falabella(9), it is grafting of the epidermis from artificially induced blister which is created in the donor area by a vacuum pump, or with the aid of liquid nitrogen. The advantage is, that the mechanical split is created exactly at the dermoepidermal junction. The recipient site is prepared by dermabrasion, laser ablation, dermatom or by creating a blister. The disadvatage of this method is transient hyper or hypopigmentations both on the donor and the recipient site.

5) hair follicle grafting

This method is based on grafting of hair follicles and on the fact that the hair follicle is an important reservoir of melanocytes. A strip of scalp about 1x3cm is taken from the temporal region. Follicle grafts are prepared in the same way as when micrograft techniques are used in treatment of androgenetic alopecia, tthe only difference is that they are cut in inferior third to remove bulb. Grafts are implanted into pits in the recipient area. Repigmentation can be observed in about 2 months and the melanocytes spread radially(10).

The major advantage of all of these methods is the possibility to treat the patients as if they were outpatients and that there is no need for special equipment and tissue banking.

II. Techniques with skin cells separation – cells grafts

The enzymatic separation of skin into cells by trypsin is provided after the harvesting of pigmented skin. After this, the suspension of skin cells is obtained. These techniques can be divided into two groups as portrayed in the next steps a) those that involve cell culture technique and b) those that do not.

a) Grafting of Cultured Autologous Melanocytes

The in vitro expansion of epidermal cells was introduced by Rheinwald and Green in 1975 for the first time and was initially used for the treatment of burn patients(11). Today the culturing of human cells is one of the most common techniques used worldwide.

The expansion of melanocytes by culturing enables treatment of larger areas. The time needed for cell culturing is about 4 weeks.

The method of harvesting and culturing of autologous melanocytes was published by A.B.Lerner and co. in 1987. They injected the cultured melanocytes into the achromatic skin leasons, where the melanocytes have produced melanin like in healthy skin. The result of this procedure was repigmentation of depigmented skin with a very similar colour like the colour of normally pigmented skin (12). Thise technique was successfully reproduced and used also by M.J.Olsson and L.Juhlin from Sweden in 1993 (13). The modification of this technique with the use of E-YAG laser for recipient skin ablation was published by R. Kaufmann from Frankfurt in 1998. The perforated absorbable hyaluronic acid matrix (Laserskin^®) was used as a cell carrier (14). The succesfull transplantation of autologous melanocytes into the skin denudeed by CO₂ laser was published by team of dr.Y.F.Chen from Taiwan in 2004 (15). Interesting technique for cultured melanocytes implantation was used by a team of doctors from Faculty Hospital in Brno, Czech republic, melanocytes were injected into skin by dermojet (16, 17).

Probably the first commercial product for surgical treatment of vitiligo by cultured melanocytes is MelanoSeed (Bio Tissue Technologies AG, Freiburg, Germany). The melanocytes are obtained from the full thickness skin biopsy, melanocytes are cultured for 28 days and the final product – suspension of cultured melanocytes in fibrin are applied on skin denudeed by dermabrasion (18).

b) (Grafting of Noncultured Melanocyte Suspension)

Grafting of noncultured melanocytes in suspension with other skin cells is a more simple and cheaper method than cultured melanocytes grafting. Suspension of skin cells is obtained from fullthickness skin or dermoepidermal graft soaked in the trypsin solution. Patients recieve suspension of autologous skin cells itself or with the cells carier. The modification of this method is different in every treatment centre.

Gauthier and Surleve-Bazeille (Bordeaux, France) described transfer of skin cells suspension into the blisters prepared in recipient site by liquid nitrogen (19). They used a scalp as a donor site and the whole procedure was provided in two days. Nanny Van Gell and coworkers (Ghent, Belgie) published in 2001 another modification, which was used on four patients. They denuded recipient site by CO₂ laser and suspension of cells reached with hyaluronic acid to achieve better viscosity of solution., which was applied onto recipient area. (20). Sanjeev V. Mulekar (India) published in 2003 group of 184 patients successfully treated with this method(21). He treated patients with focal, segmental and generalised vitiligo with lesions stabile for 6 months on maximum 30% of total body surface area. He used buttock as the donor site for dermoepidermal skin graft. The size of dermoepidermal graft was aproximately 1/10 of the size of the treated area. The recipient area was abraded down to the dermo-epidermal junction with a high-speed derm-abrader and cell suspension was applied evenly on the denuded area and covered with collagen (Collcor CX, Sweden) and with a sterile gauze moistened with DMEM F12 medium and everything was covered by transparent covering.

Conclusion

Loss of pigment in repigmented areas after succesful surgical treatment is not frequent, but has been published before and patients must be informed about this possibillity(22). The maximum size of the treated area in one session is limited by the number of grafted melanocytes and it´s about 200cm² because it is necessary to have an acceptable size of the donor area (18).

Surgical treatment by grafting of autologous melanocytes cultured or is a good method for treating mainly small, stabile areas of depigmented skin up to 100cm² in one session. acording to literature and our own experiences. With patients with occurrence of larger areas of depigmented skin with no response to medical therapy there is a need for expansion of melanocytes so that the treatment can be successful. The surgical treatment by grafting of autologous melanocytes became a currently available treatment with a high rate of good outcome within the last ten years. However, this method is expensive and requires a tissue culture laboratory setup and that´s why this procedure is not so common.

Evžen Trupar, MD

Department of Burns and Reconstructive Surgery

Faculty hospital Brno

Jihlavská 20, Brno, 639 00, Czech Republic

email: trupare@seznam.cz