What Is a Skin Transplant?

Autogenous skin transplantation is a common method for treating skin defects caused by trauma, burns, and other factors. Skin grafting involves the free grafting of skin tissue alone and the transplantation of pedicled skin flaps or skin tubes with simultaneous transplantation of skin and subcutaneous tissue. The survival of the transplanted skin depends on whether the transplanted skin and the percutaneous tissue have established effective blood circulation. The factors that affect the survival of the transplanted skin or flap include wound infection, skin movement, compression of the pedicle of the skin tube or flap, or excessive fat in the skin tube. Hyperbaric oxygen treatment can help the success of skin transplantation.

Skin graft

Autogenous skin transplantation is used to treat trauma,

Under hyperbaric oxygen, the increased oxygen partial pressure and oxygen storage in the tissue can enhance the growth vitality of the tissue in the skin area, promote the growth of granulation tissue, reduce wound exudation and bacterial infection, make the wound fresh and clean, and create good conditions for skin grafting. .

Before the blood circulation of the transplanted skin or flap and the skin area has not been established, the high partial pressure oxygen in the tissue can reduce the persistent hypoxia caused by the lack of blood supply to the transplanted skin, which is beneficial to the transplanted skin. survive.

The ability of cells to divide and proliferate is closely related to the partial pressure of oxygen in the tissue. When the oxygen partial pressure of extracellular fluid is lower than 1.3kPa (10mmHg), the cell no longer divides and no longer synthesizes

Rhinoplasty

Skin graft

The number of free skin flaps is less than the expected number of completed catalogues; after surgery, a part of the skin thickness or a full-thickness skin flap is cut, completely separated from the body (the donor area), and transplanted to another place (the skin). Area), re-establish blood circulation and continue to maintain vitality for the purpose of plastic repair. Therefore, the extraction of the skin, the choice of the donor area, the method of transplantation, how to rebuild blood flow, how to ensure the survival of the skin after surgery, whether it can achieve the purpose of repair, etc., all need to consider the thickness of the skin to be transplanted Appropriate, well established blood flow and good survival.

Skin graft

Skin grafts are divided into three types: thin (superficial or blade thick skin), medium (faulty or medium thick skin), and thick (full or full thickness skin). . There are two ways to cut the skin:

1. The method of taking the skin is to use a long, thin and sharp leather knife and two wooden boards. When removing the skin, the skin surface of the donor area remains flat and tense. The surgeon holds a knife in his right hand and presses a wooden board on the donor area with his left hand. Another assistant stretches the skin in the opposite direction with the wooden board and grips the skin on the opposite side of the donor area. Then use a knife to cut into the skin layer, often back to the sawing action, you can cut off the required skin piece. The thickness of the skin depends on the angle between the blade and the surface. The larger the angle, the thicker the skin (Figure 1).

2. The peeling machine (Figure 2) used for mechanical peeling is relatively smooth, with uniform thickness and neat edges. Skin thickness is in units of 1 (Note: This unit is reserved for clinical operation), when 1 division on the scale on the skin-cutting machine is 5 . In general, when the epidermal sheet is 8 -10 , when the thin medium-thickness sheet is 12 -20 , and when the thick medium-thickness sheet is 22 -30 . When slicing, first apply glue to the drum and skin to stick to the skin, and the range depends on the size of the skin. The surgeon holds the handle in his left hand and the knife holder in his right. The front edge of the drum is in contact with the skin supply area, then lightly pressed and then turned upwards. Lift up and pull the knife holder to cut to the required size (Figure 3).

Skin graft flap graft

Skin flaps are also called pedicled skin grafts. The modern point of view is that a skin flap is a tissue block composed of skin and subcutaneous tissue that can be transferred from one part of the body to another. During the transfer process, one or two pedicles need to be connected, or they may not be connected for the time being, and the blood vessel anastomosis is performed after transplantation. The flap's blood transport and nutrition relied on the pedicle supply early on. When the flap healed at the transplant site about 3 weeks later, a new blood circulation system was gradually established, and then the pedicle was cut off, and the flap transplantation process was ended.

Skin graft

Pedicled skin is called a skin flap. The surgical procedure includes three steps: formation, transfer, and broken pedicle. It takes a long time and is more complicated than skin grafting. There are two types of skin flaps: flat skin flap and skin tube.

1. Flat skin flaps are often used to repair nasal defects. Adjacent frontal skin flaps are mostly used, and the thickness and color after repair are similar to the defect area, and the effect is better.

2. The skin tube makes two parallel incisions with the long axis aligned with the main blood vessel at the intended site of the skin. The incision is peeled from the incision to the contralateral surface of the fascia until the contralateral incision forms a skin band. Tightly stop bleeding and sew into a leather tube (Figure 4). The wound margin of the donor site is widely free, and suture is reduced after reducing the wound tension. The ratio of the length to the width of the leather tube should not exceed 2.5 to 3: 1, otherwise it will not be easy to survive. After the formation of the skin tube, pay attention to the blood flow and do not twist the pedicle to avoid necrosis. Three to four weeks after the formation of the tube, the pedicle was cut off after 3 to 4 weeks of transfer. Before breaking the pedicle, use a thin rubber band to perform compression training on the pedicle to temporarily block blood flow and prevent survival due to sudden decrease in blood flow.

Close observation should be performed after transplantation to check for blood circulation disorders, secondary bleeding or inflammatory infections. The above three are the main reasons for the failure of transplantation. Therefore, it is necessary to design carefully before surgery, pay attention to the main blood vessel in the donor site, and enable the establishment of favorable blood circulation. The operation during the operation should be gentle, avoid excessive trauma, and be proper Hemostasis, tight sutures, and no gaps are left, which is not only conducive to fixation, but also prevents bleeding, and does not cause hematomas to cause infection. This is the key to the success of the transplant and the prevention of complications.