Analysis of Grafting Techniques

Analysis of Grafting TechniquesProcedure In this method a split-thickness skin transfering is harvested from the presenter site, either second joint or buttocks. It is then meshed either manually or in an Ampligreffe or any other qualified meshing apparatus.40,41 Meshing of the graft causes an expansion in its size to 4 or 6 measure its original one. The meshed graft is then applied on the dermabraded recipient skin and bandaged as in any other form of wander grafting. The main advantage of this technique is that the graft can take c atomic number 18 of a vitiligo lesion that is 4-6 times that of its original size. Additionally meshing allows the graft to be applied on areas over joints and other areas with difficult contours.This technique is increasingly being practiced in India and is a simple, cost- putive affair with good cosmetic results. convention In this technique of vitiligo, grafting the split-thickness or ultra-thin skin graft is cut or unwavering into very smo oth pieces and applied to the dermabraded recipient skin.42,43The conferrer recipient ration is approximately 110.Procedure A split-thickness or ultra-thin skin graft is setoff taken from the donor area preferably thigh or buttocks. It is then smashed/cut into thin pieces.The cutting process is continued till the graft is converted into a uniform mesh or paste. This mesh is then mixed with either hyaluronic acid or antibiotic ointments and is then spread as over the dermabraded recipient area as in any other form of tissue grafting.42 The recipient area is then covered with a collagen fertilization and this dressing is take away after 7-8 days. The advantage of this method is that a relatively larger area can be covered by a small sized graft. The results are almost similar to those achieved with non-culture epidermal cubicle rest period (NCES) technique. Additionally, no expensive reagents or laboratory support is required as in NCES procedure. Some difficult to treat areas l ike the pigy skin, the joints and bony prominences can also be treated with this technique. The disadvantage is that it is difficult to spread the grafted tissue as on to the recipient area.Figures 34.7 and 34.8 shows good results with smash graft on joints.Three main cellular grafting techniques are described in the world literature. These are non-culture epidermal cell suspension technique, cultured melanocyte transplant and non-culture follicular suspension techniqueSynonyms non culture melanocyte transplant, non-culture melanocyte-keratinocyte cell transplant (NCCT), basal cell suspension technique.Principle The different cellular components of a STSG are separated and a suspension is prepared out of these cellular components. The suspension contains epidermal keratinocytes and melanocytes this is applied on to a dermabraded recipient area. The donor recipient ration is 110.In this cellular grafting procedure a split-thickness skin graft is harvested from a suitable donor area and this is treated with 5 ml of Trypsin-EDTA solution for about 45-60 minutes in an incubator at 37C. This step separates the cells of the epidermis from the underlying dermis. The conterminous step is the neutralization of Trypsin which is achieved either by using 2 ml of 0.5% trypsin inhibitor solution or washing the graft with DMEM or any other suitable medium repeatedly. The treated graft is then taken in a petridish with the epidermal side downwards and the dermal cells are teased out of the graft with forceps. The overlying dermal tissue is discarded and the solution with the cellular component is centrifuged for about 10 minutes at the end of which the cells pellet are seen hang at the bottom of the centrifuge tube and the epidermal pieces are floating at the top, which is discarded. The cell pellet is then mixed with a about 0.8 ml of Dulbeccos Modified Eagles Medium (DMEM) medium (also called M2 melanocyte medium) and the suspension thus obtained is transferred to a 1 m l tuberculin syringe. After the recipient bed is created, the cell suspension is spread thinly and evenly with a spatula on to the dermabraded recipient skin after removing needle. The area is then dressed with collagen dressingto hold the transplanted cells and the dressings are removed after 1 week. As an alternative to the DMEM medium, patients own serum or hyaluronic acid can be utilize as it improves the viscousness of the cellular suspension.53This technique requires expensive laboratory equipment and is usually practiced only at research centres.Principle It replenishes melanocytes selectively by creating a melanocyte rich suspension. The donor recipient ration can be as high as 1100Procedure The epidermis undergoes trypsinization and the melanocytes and keratinocytes are dissociated. The melanocytes are further seeded in a melanocyte medium containing growth factors and cultured over 15 to 30 days. The cultured melanocytes (free suspension or epidermal sheets) are then tr ansplanted on to dermabraded recipient skin.This is a novel cellular graft technique by using the vibrissa follicle outer root sheath cell for transplant. Cosmetic results obtained with this procedure are almost similar to those seen with NCES technique.Principle This is another cellular grafting technique wherein the melanocytes present in the hair follicles are utilized in repigmenting insubordinate vitiligo. The outer root sheath of the hair follicle is a rich source of inactive melanocyte. Theseinactive melanocytes function as stem cells and hence can be harvested and used in vitiligo.Procedure The procedure is almost similar to NCES technique but here extracted hair follicles are used instead of a split-thickness skin graft. The hair follicles can be extracted by the follicular unit extraction (FUE) method. The hair follicle is decontaminated by washing with antibiotics. Enzymatic dissociation of ORS is done by addition of trypsin and incubated at 37 C.Mechanical disruption o f the ORS is done by vortexing and the ORS cells are separated from the hair shaft by a cell strainer. The dissociated cells are examined microscopically for viability and the cell suspension can be transplanted onto the prepared recipient site. This technique is in a nascent stage, however it has shown good repigmentation comparable to NCES .The surgical techniques discussed above throw unhomogeneous advantages and disadvantages. (Table 34.3) 50, 58Table 34.3 Advantages and Disadvantages of grafting techniquesIn addition to the grafting techniques, various other methods also have been used including tattooing, excision with primary village and therapeutic wounding.Tattooing In tattooing, artificial pigments are introduced into the depigmented lesions for permanent camouflage. This can be done with a hand held pin vise or an electrical device.Excision with primary closure The depigmented areas are removed and the wound is sutured this technique is useful for small vitiligo lesion s.Therapeutic wounding Wounding of the lesions stimulate the melanocytes from the periphery of the lesion as advantageously as from the hair follicles which migrates and re-pigments the lesion. Various modalities which are used for therapeutic wounding include dermabrasion, laser ablation, cryosurgery, needling, and local application of phenol or trichloroacetic acid. 59Besides the technical aspects of various procedures (detailed in the earlier section), the other important practical aspects includeChoice of technique (Which procedure should be performed, where and why?)General pre and post-operative considerations,Role of phototherapy,Complications and their management.The choice of technique depends on the dermatosurgeons skills, experience and the availability of facilities in the dermatosurgery set up. However, the factors which are considered while planning a vitiligo surgery also determine the choice of surgical technique employed. establish on these factors, an algorithmic approach to choosing an appropriate surgical technique in stable vitiligo can be evolved. (Illustration 34.3In cases of pediatric segmental vitiligo, NCES is suitable. It can be followed by phototherapy for faster results. Tissue grafting techniques are usually not recommended due to constraints of immobility in this population subset. In adult, population both tissue grafting and cellular techniques can be employed based on the site and total area of depigmentation.Segmental and focal vitiligo are most tractable to surgical treatment. Amongst the non- segmental type, lesions located on the glabrous skin are suitable for surgical intervention. The acromucosal types are usually not responsive.The location of the lesion plays an important power in determining the choice of grafting technique. (Table 34.4)Table 34.4 Anatomical location and choice of grafting techniqueSmall areas (1-4 cm) All techniques work well in vitiligo involving small areas (1-4 cm) and technique should be chos en based on anatomical location and cost to the patient. In cases of large areas, NCES, smash or UTSG is preferred.The general pre and post-operative aspects have been outlined in Box 34.6. Specific pre and post-operative procedural aspects have been dealt with in the description of procedures.Box 34.6 General pre and post-operative aspectsThe role of phototherapy (narrow band UVB) post vitiligo surgery has been well demonstrated with various tissue grafting and cellular techniques. Phototherapy can be started within 1-2 weeks following surgery. Concurrent use of narrow band UVB exerts a stimulatory and proliferative effect on the grafted melanocytes thus post- surgery phototherapy enhances and accelerates the repigmentation.In cases of UVB therapy which is initiated after split thickness skin grafting, repigmentation can occur within two weeks and a better emblazon match at the recipient site is seen. Repigmentation with cellular techniques has been observed within 3-4 weeks after surgery and can progress till 6 months and this can be enhanced with phototherapy. Use of excimer laser has also shown good results post punch grafting.