Skin graft: when is it used?

Skin grafting is a surgical technique that allows skin defects to be covered with tissue from another part of the body. Find out more about this intervention.

Last update: 01 July, 2022

The skin is the organ that covers our body and serves as a barrier to the world around us. In this way, it protects against infections and also safeguards the conditions of the internal environment. Some skin lesions are so extensive or complex that they require the use of a skin graft to treat them.

The purpose of this type of surgical treatment is to confer indemnity to the tissue. In this way, the underlying structures are protected and the barrier effect of the skin is guaranteed. In the end, not only is the defect caused by the injury covered, but an attempt is made to create aesthetic results. Next, we tell you more about it.

What is a skin graft?

A skin graft is a piece of skin that is obtained through surgery. In this said piece is completely separated from a body region —called donor—, to then transplant it to the recipient site, that is, the place that has a defect or injury.

Since it separates from its donor site, the graft loses its blood flow. For this reason, the recipient tissue must have the ability to provide adequate blood supply. In this way, the transplanted skin can be revascularized and, therefore, will be able to survive in its new location.

Skin grafting allows recovery of the skin barrier function in the event of severe injuries.

Layers of skin

To understand the types of skin grafts that exist, it is necessary to know the histological layers of the skin. The epidermis is the most superficial layer. This structure lacks its own blood vessels. and receives irrigation from the deeper portions of the skin. This causes epidermis-only grafts to fail and are therefore of no use.

On the other hand, the deepest layer of the skin is the dermis. In turn, this can be divided into two portions; the papillary dermis and the reticular dermis. The first is the most superficial layer, so its blood vessels are the ones that allow the nutrition of the overlying epidermis. Under the dermis, there is the subcutaneous cellular tissue, which is rich in fat.

Types of skin graft

The most used classification in skin grafts responds to the thickness of the skin involved. In general, two types are accepted; split-thickness grafts and full-thickness skin grafts.

  • Split thickness grafts: the thickness is variable, but it must always contain a portion of the dermis. This guarantees the donation of the necessary elements for cell regeneration and nutrition of the overlying epidermis. Depending on the thickness of the dermis involved, the thickness of this tissue can be more or less thin.
  • Full thickness grafts: the sectioned skin fragment has both the epidermis and the entire dermis. The tissue must be devoid of subcutaneous fat to allow neovascularization.

Depending on how the skin graft is used

According to the need to cover the defect, the grafts can be continuous, that is, those formed by one or several fragments which, by joining together, manage to cover all the loss of substance.

Similarly, there are discontinuous skin grafts, in which the defect is not completely covered. Among these are the following options:

  • Meshing of Tanner and Vandeput.
  • Multifragmented graft.
  • Graft in Trueba bands.
  • Gabarro seals.
  • Davis graft or pill.

Special situations

The choice of one type of graft over another responds to several questions. The localization of the loss of substance is of great importanceas well as the selection of the donor site.

Likewise, the extension of the lesion will allow considering a type of graft. In the meantime, the cause of the substance loss helps the surgeon to choose the most suitable thickness.

Characteristics of skin grafts

Depending on the thickness of the fragment, each type of graft has some advantages over others. Also, the injured tissue also plays an important role in the “taking” of the graft, that is, in making the technique successful. Some of the features to consider are described below.

donor and recipient

Since the skin has a high antigenicity, skin grafts can only come from the same person. This is because the immune system is not able to recognize elements other than its own. Therefore, an immune response is unleashed that ends up rejecting the grafted tissue.

To this type of transplant —in which the donor is the same individual as the recipient— These are known as “autografts.” However, there are situations (such as major burns) in which the use of cadaver or even pig skin grafts is of some use.

Donor tissue conditions

The choice of the site from where the skin graft will be taken must be carefully to guarantee the best possible result. Thus, the fragments usually come from places close to the lesion. In general, the following recommendations are suggested:

  • It should be similar in color to the recipient site.
  • In cases of tumor resection, it is advisable to choose the contralateral limb to take the graft.
  • The tissue must be free of infection.
  • The texture and distribution of hair between both sites (donor-recipient) is recommended to be similar.

Conditions of the injured tissue

The recipient bed is the bottom where the skin graft must adhere. This must have abundant vascularization to allow the new tissue to survive. However, the presence of infections or hemorrhages decrease success rates, so they must first be treated.

Situations in which skin grafting is useful

Despite representing a solution for complex skin lesions, not all locations on the body allow skin grafts to be the best option. Despite this issue, the main situations in which they are used are the following:

  • Big burns.
  • Extensive wounds.
  • Resection of skin tumors.
  • Ulcers in lower limbs.
  • Defects of mucosal areas.
  • Fasciotomies.
Skin grafts can only come from the same person; otherwise, an immune response occurs that rejects the tissue.

wound healing

In addition to providing vascularization of the tissue, the recipient bed can produce retractions in the skin graft, especially if it is partial thickness. For being right, it is recommended that in aesthetic areas such as the face, full-thickness grafts be used, since they show better coverage and entail less shrinkage.

On the other hand, when the loss of substance is very extensive, it is more appropriate to make fragments of partial thickness, which are also discontinuous. Meshing, for example, allows the dimension of a continuous skin graft to be increased up to three times. This expands the coverage capacity of the fragment, although it represents less aesthetic results.

Skin graft complications

As with any surgical treatment, there are some risks with skin grafting. The most common include the following:

  • hemorrhages
  • Bruises.
  • Seromas.

On the other hand, retractions, scars and pigmentation changes can affect the final appearance of the skin graft. In these cases, additional dermatological procedures may be recommended to enhance the final appearance.

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