Skin Transplantation

Our skin is not only the largest, but also a very important organ, so trauma and pathology with serious damage or loss of skin can be life threatening. Transplantation or skin grafting is the most common way to restore the integrity of the skin.

[1], [2], [3], [4], [5], [6], [7], [8]

Indications for the procedure

The main indications for the behavior of skin transplantation are related to kobustiology: if more than 10% of the skin of the body is burned, then a skin transplant is performed after a burn of grade 2, but most often it is necessary for  skin burns of grade 3, when the basal layer of the epidermis and all layers of the dermis break. And with burns of 4 degrees, a delayed transplant is performed.

In traumatology, skin transplantation is applied in the treatment of extensive injuries - lacerated, crushed, scalped - with considerable area and volume of damage. Such wounds can not heal by primary tension, and filling of their cavity occurs due to the proliferation of fibroblasts and the formation of granulation (connective) tissue.

Skin is transplanted with trophic ulcers - long-term healing inflammations with dermis necrosis and hypodermis caused by diabetes mellitus, varicose veins, obliterating thromboangiitis or  thrombophlebitis of the lower extremities, lymphostasis or vasculitis.

When  frostbite of the  limbs, leading to the death of skin tissue, it may be necessary to transplant the skin on the leg (often - on the feet of both legs) or skin transplantation on the arm.

Serious  defects and deformities of the skin of the face and neck, including ulceration after phlegmon are the main reasons for skin transplantation on the face.

In all the cases listed, a skin transplant is done to the child, regardless of his age.

Reconstructive surgery - skin flap transplantation - helps to improve the quality of life of patients after surgical removal of dermatological malignancies (most often - melanoma), as well as patients with dystrophic  bullous epidermolysis.

Is skin transplantation possible with vitiligo? This autoimmune dermatological disease with the formation of whitish spots on the skin in some foreign private clinics is taken to treat melanocytes (producing the pigment of epidermal cells) from healthy areas of the skin to discolored spots, followed by exposure to an excimer laser. The method of cellular autotransplantation of cultured melanocytes is also used.

But the skin transplantation with stretch marks (striae), associated with atrophic skin changes, is not provided: for the treatment of band-shaped atrophodermia, various local action and apparatus methods are used. Read more about them -  Stretch marks: what causes and how to get rid?

[9], [10], [11], [12], [13], [14]

Preparation

In addition to the conventional preoperative examination, preparation for skin transplantation consists in stopping the inflammation of the damaged surface (burn, wound, affected by trophic ulceration, etc.), which is completely cleared of pus and necrotic tissue, performing necroctomy. This takes a certain time, during which patients are prescribed the appropriate drugs and physiotherapy, as well as microbiological examination of the excretions from the wounds (a cytogram for the presence of pathogenic microorganisms) and monitoring the state of the granulation tissue in the wound bed.

Also, to close the defect, it is necessary to prepare the transplanted material. If it is possible to transplant the patient's skin flap (autotransplantation), then he also takes a flap of healthy skin (a special tool - dermatome).

Where do they get the skin for a transplant? The main donor zones are the places from which the autograft is taken: buttocks, anterior abdominal wall, hips (front and outer surfaces), thorax (anterior and lateral surfaces), shoulders (upper arms from the shoulder joint to the ulnar joint). The necessary size and thickness of the skin flap surgeons are accurately determined in advance - depending on the area and depth of damage, as well as its localization. Rags can be as thin (split, consisting of only a few epithelial layers), and thicker (full-layer, with part of the subcutaneous fat).

In order for the donor sites to heal quickly and without complications, the hemorrhage stops and the wound surface dried, on which sterile bactericidal dressings with silver ions are applied: a micro-array of such dressings absorbs the exudate, not adhering to the wound, and promotes the formation of a dry scab under which the wound heals.

When a thin flap is taken, a solution of potassium permanganate can be used to treat the donor zone, and then surgical collagen coatings for the wound. And narrow wounds after excision of a flap, as a rule, are sutured with imposing of an aseptic pressing bandage.

In the burn centers, donor sites are closed with lyophilized xenoderm grafts (from the skin of pigs); they can temporarily close extensive burns of 2-3 degrees, and after a while on the wounds prepared in this way are transplanted autografts.

If the patient's own skin can not be transplanted, another person's skin can be used - allogeneic transplantation (allotransplantation). In addition, explants are used abroad - artificial skin for transplantation (Integra, Silastic, Graftskin), which is a collagenous lattice frame (in some cases - with cultured human epidermal cells), which becomes a matrix for the ingrowth of fibroblasts, capillaries, lymphatic vessels and nerve fibers from a healthy tissue surrounding the wound.

Based on innovative technologies of regenerative biomedicine using  mesenchymal  blood stem cells and induced pluripotent bone marrow stem cells, it is possible to grow skin for transplantation after burns. But for the time being it is quite a long and expensive process.

[15], [16], [17], [18], [19], [20], [21], [22]

Technique of the skin transplantation

The technique of transplantation is described in detail in the publication -  Surgery for skin transplantation after a burn

Before placing the flap in the bed of the wound, decompression necrotic surgery is performed (the resulting scab on the burn wound is dissected) followed by treatment with antiseptics.

In most cases, the transplanted autograft is held by several small stitches or surgical staples. Drainage is applied and a compression bandage is applied.

Specialists note the peculiarities of technology and donor sites when transplanting the skin on the hands. So, for a free skin transplant the child with burns of the palmar surface uses a full-fledged flap, which is taken from the inner surface of the thigh. In adults, in the same cases, it is common practice to close the wound with gauzes from any donor zones, as well as from the plantar side of the feet.

Skin transplantation on the fingers is often compared with jewelry work, and here are used a variety of techniques, the choice of which is dictated, first of all, the localization of damage and the presence of healthy tissue near it. So it can be performed as a free autoplasty (with flaps in the back of the hands, from the shoulder, etc.), and not free - by cross-flaps with intact phalanges, flaps on the feeding stem, etc. If you need a skin transplant on the pads of the fingers of the hand, then it is carried by the patient's skin patches taken from the inner thighs.

A separate problem is post-burn scars, disfiguring appearance and deforming limbs with joint contracture. When neither drug treatment, nor physiotherapeutic methods give a positive result, go for skin transplantation. But this is not a literal translation of the skin onto the scar: first scar tissue is excised and only then the defect is closed, most often by the method of moving counter (not free) triangular flaps over Limberg.

Methods of skin transplantation

The main methods of skin transplantation are:

• free skin grafting, when the transplanted flap is insulated, that is, from the place where it was cut, it is completely cut off;
• unfree skin transplantation - either by transposition of partially separated fragments of healthy skin next to the wound, or by means of a migrating (flap) flap connected to the skin of the donor zone by the so-called feeding stem. It is cut off only after the full engraftment of the displaced flap.

There is also a method of non-free autodermoplasty with the help of a stem flap - a skin transplant by Filatov, when a flap in the form of a stem is formed from a longitudinal striped skin strip (obtained by two parallel incisions), which is sewn along along the entire length. The ends of such a "stalk" are associated with the skin (in fact, these are two feeding legs), and when the flap is sufficiently vascularized, its distal end relative to the wound is cut off and sutured to the desired place.

To date, there are many modified versions of the Filatov method, first used in the early twentieth century. Although before the skin transplant by Filatov used techniques with flaps of Gakkera, Esser, and non-free transplantation of the scalp was carried out (and is still carried out) by a flap of Lekser.

The classification adopted today for the technique of free skin transplantation includes:

• Use of a full-fledged flap (in the entire thickness of the skin), which allows to cover insignificant in the area, but sufficiently deep burns and wounds. Such autografts are used when skin transplantation on the face and distal limbs (feet and hands) is necessary;
• restoration of lost skin in one area with a single, thin (epithelial) flap;
• application of a split flap divided into strips - skin transplantation by Tirsch;
• closure of the defect with several isolated small flaps - skin transplantation by Reverden (modified Yatsenko-Reverden technique);
• transplantation of a split perforated flap, on which longitudinal rows of short interrupted cuts are made (with a displacement in the type of brickwork). This allows the transplant to stretch and cover a larger area, and also prevents the accumulation of exudate under it, which is extremely important for the good survival of the flap.

Contraindications to the procedure

Among the medical contraindications for skin transplantation behavior are:

• shock or febrile state of the patient;
• Burn toxemia and septicotoxemia;
• presence of local inflammatory process at the site of transplantation;
• significant hemorrhage;
• serous and serous-hemorrhagic diseases of the skin;
• elevated levels of protein fractions and / or leukocytes in the blood, low hemoglobin (anemia).

[23], [24], [25], [26], [27], [28], [29]

Consequences after the procedure

First of all, the consequences after the procedure of skin graft transplantation can be, as with any surgical intervention, in the form of a reaction to anesthesia, hematoma and edema, bleeding, and the development of an inflammatory process due to infection.

As a complication after the procedure, there are:

• destruction of the graft (due to poor blood flow at the transplant site or accumulation of exudate);
• rejection of the skin flap (as a result of its inadequate preparation or non-sterility of the wound bed);
• deformation (shrinking) of the transplanted flap (especially split) with a decrease in its size;
• enhanced pigmentation;
• gross  hypertrophic scars, scars after skin transplantation (with limited mobility of limb joints);
• decreased sensitivity of the skin at the site of transplantation.

A complication such as a dent after a skin transplant can be related to both postoperative necrosis in the wound and the fact that the thickness of the skin flap did not correspond to the depth of the defect or the level of granulation in the bed of the wound was insufficient at the time of transplantation.

[30], [31], [32], [33], [34], [35], [36]

Care after the procedure

Postoperative care consists in bandaging, taking prescribed medications (analgesic, antibacterial); the state of the surgical zone is processed after a skin transplantation - using antiseptic solutions (for example, Furacilin, Dioxydinum, Diosizolum, Sodium deoxyribonucleate), as well as corticosteroids.

On what day does the skin get stuck after the transplant? Transplanted skin usually begins to heal three days after the operation. First the flap is fed by plasma absorption, but after 48-72 hours - as it revascularises (the growth of new blood vessels) - the trophic of the transplanted skin begins to provide microcirculation in the capillaries.

This process lasts not less than three weeks, and how much the skin gets attached after transplantation in each specific case, depends on a number of factors. Firstly, the reason causing this operation, and the scale of the loss of the skin, play a role. The age of the patient, the state of his immune system, the reparative reserves of the body and, of course, the presence of certain diseases in the anamnesis are of no small importance. Of great importance is the thickness of the transplanted skin flap: the thinner it is, the quicker it becomes.

For healing after skin transplantation without complications, anti-inflammatory ointments after skin grafting can be used: Levomecol, Miramistin, Metiluracil, Dermazin (with sulfadiazine of silver), Depanthenol. More information in the material -  Ointments for wound healing

Restoration of the skin after transplantation takes at least two to three months, but it can last longer. Patients should support the transplant with compression knitwear. In addition, the transplanted skin does not emit sweat and sebum, and it should be lubricated daily for two to three months with mineral oil or other mild oil to prevent drying out.

Nutrition for skin transplantation should be complete, with an emphasis on proteins of animal origin - to ensure the entry of amino acids and nitrogen compounds into the body. Of the trace elements, zinc, copper, manganese, selenium are especially important during this period, and vitamins are retinol (vitamin A), pyridoxine (vitamin B6) and ascorbic acid (vitamin C).

[37], [38], [39], [40]