What Is a Free Flap?

Skin flaps are formed from skin with blood supply and its attached subcutaneous adipose tissue. During the formation and transfer of the flap, a part must be connected to the body (the area where the flap is supplied). This connected part is called the pedicle to maintain blood supply. The other parts are separated from the body on the deep and deep sides and transferred to another part. After a wound (the flap area), nutrition is still supplied by the pedicle blood supply. After the blood vessels in the flap area grow into the flap, new blood flow is established, and then the pedicle is cut off to complete the flap transfer. The whole process is also called pedicled flap, but the partial pedicle or island flap does not need to be broken after transfer.

Skin flap

1. According to the distance between the donor area and the recipient area, it can be divided into local, adjacent, and distant flaps.

(1) Local skin flaps: skin flaps taken from tissues surrounding the defect, including advancement flaps, rotation flaps, translocation flaps, etc .;

(2) Adjacent skin flap: skin flaps taken from adjacent parts of the defect, such as the forehead skin flap used for nasal reconstruction.

(3) Distant skin flaps: skin flaps taken from parts farther away from the defect, including direct far skin flaps, indirect far skin flaps, and free skin flaps.

2. According to the blood supply mode of the flap, there are random and axial flaps.

(I) Random-type flaps: 1. Local flaps (sliding and advancing flaps, rotating flaps, staggered or translocated flaps)

2. Prosthetic flaps: 3. Distant flaps (including direct flaps, direct carrying flaps, tubular flaps, free flaps)

(2) Axial skin flap 1, general axial skin flap 2, island flap 3, myocutaneous flap 4, free anastomotic flap

5. Free grafting of skin composite tissue with vascular pedicle (including musculocutaneous flap, combined flap, prefabricated axial flap)

3. According to the composition, there are simple skin flaps, fascial skin flaps, myocutaneous flaps, and musculocutaneous flaps.

4. According to the transfer mode of the flap, there are rotation, advancement, translocation, flip, cross, instant and delay, direct and indirect transfer, and free flaps through anastomotic vessels;

5. According to the shape of the flap, flat flaps, diamond flaps, triangular flaps, pouches, island-shaped flaps, and Z-plasty, W-plasty, V-Y surgery, Y-V surgery, etc. Formation of skin flaps.

6. According to the condition of the pedicle, there are single pedicle, double pedicle, subcutaneous pedicle, vascular pedicle, vascular and neural pedicle flap, etc.

In addition, there are functionally named flaps, such as lining flaps, and flaps named after the donor site, such as inter-fish flaps for repair of fingertip trauma.

(1)

(1) Strictly observe the blood flow of skin flaps. Through skin temperature, skin color, swelling degree, capillary response and other indicators, patiently and comprehensively observe, comprehensively judge, and detect problems early for early treatment.

(2) Skin color The main observation is whether the skin tone of the transplanted tissue is ruddy, pale, reddish purple. Because the skin color of different parts of the human body is different, pay attention when comparing with the skin color of the donor and the skin area, and the skin color of the skin area. If the skin becomes pale or pale, it indicates insufficient arterial blood supply, embolism or spasm. Conversely, blockages or darkening of the entire color should be considered as hindered venous return. As the thrombus worsens, it becomes red or purple. In this group of 4 cases of flap necrosis at the edge of the skin, due to the use of local baking lights at the time, which affected the observation of skin color, did not attract the attention of the nurse, and eventually led to flap necrosis.

(3) Skin temperature Compare with adjacent normal tissue. Generally, the temperature difference between the graft skin temperature and the healthy side skin temperature is 0.5 ° C-2 ° C. If the temperature difference is less than 2 ° C from normal skin temperature, it indicates that blood circulation disorders will occur. If the skin temperature suddenly rises above the normal range, and there is a local tingling sensation or the pain continues to worsen, it indicates that an infection is possible. Transplanted skin flaps are often covered with multiple layers of gauze to protect them from external temperature. In this group of 2 patients, the skin temperature began to increase 4 days after the operation, and the pain worsened, and eventually healed due to subcutaneous infection.

(4) Swelling degree The flaps have edema process after operation. After 3-4 days, the veins gradually communicate, and the venous return of the flaps can be rapidly improved and swelling. Depending on the degree of swelling, the presence of skin lines, disappearance of skin lines, and blisters may occur. Insufficient arterial blood supply The skin flap collapses and the skin texture increases; the venous return is blocked, the skin texture disappears, the tension increases, the surface is bright, there are blisters or skin texture bleeding, and the degree of swelling does not change when the arteriovenous is embolized at the same time.

(5) Capillary reaction Press the skin of the flap with a cotton swab to make the skin white, then remove the cotton swab, and the skin color will turn red. This time is the capillary filling time, which is normally 1-2s. If the capillary filling is slow or disappears, the blood circulation may be interrupted and attention should be drawn immediately. The author believes that the observation of capillary filling time should be comprehensively analyzed with other indicators.

(6) Judging the growth of the skin flap You can pierce the skin with a nail head 5mm, and then squeeze the surrounding tissues gently after extraction. If bright red blood overflows, it is normal. If blood is not seen after repeated acupuncture, it may indicate an arterial crisis; if dark red blood overflows, venous blood flow is blocked. If you find any of the above, you should inform your doctor in time to avoid necrosis of the myocutaneous flap. Early detection, early processing is key.

(7) Insulation care Insulation is particularly important after operation. The flap is irradiated with 60W baking lamp for 7-10 days, and the baking distance is 30-40cm. Cover the lampshade and flaps with a sterile towel to keep them warm, but be careful not to get too close to the flaps to avoid burns, and intermittent exposure in summer.

(8) Postoperative position Postoperative position placement is one of the important measures to ensure the blood supply and venous return of the flap and promote the survival of the flap. Keep the affected limb higher than the heart after surgery, raise the affected limb 10 ° -15 °, maintain the functional position or adjust it appropriately according to the surgical site. To ensure arterial blood supply and facilitate venous return.

The affected side is forbidden to prevent the flap from being compressed or stretched to avoid ischemia and necrosis of the flap due to flap spasm. Try to take a position that satisfies the patient. Always visit the patient, especially the sleeping patient. Pay attention to maintaining the position. At the same time, explain the importance of the fixed position to the patient, make it cooperate closely with the treatment, and correct the incorrect posture in time.

(9) Pain care Pain can make the body release serotonin (5-HT). 5-HT has a strong vasoconstrictive effect. If not treated in time, it can cause vasospasm or thrombosis. Therefore, it should be given analgesia in time after surgery. The local bandage is fixed to protect the limbs and avoid damage to the skin flap during exercise, causing pain, and the bandage should not be too tight to prevent compression. All postoperative nursing exercises are gentle, such as injections, infusions, dressing changes, and drainage tubes, to minimize pain.

(10 ) Maintaining effective blood circulation Insufficient blood volume can cause reduced stroke volume and peripheral blood vessel contraction, which affects the flap blood supply and threatens the survival of replanted tissue. Therefore, attention should be paid to the vital signs and systemic conditions after surgery to supplement blood volume. At the same time, anti-spasm and anti-thrombotic treatment should be given according to the doctor's advice, and the curative effect and side effects of the drug should be observed.

(11) To prevent the infection of wounds, apply antibiotics in a timely and reasonable manner in the early stage, strictly operate with aseptic technique, keep the dressing clean and dry, and keep the drainage of the skin smooth. Observe the color, amount, and nature of the drainage fluid and make a record to prevent blood accumulation in the skin gap of the flap. Affects flap survival. Give dietary instructions, and ask to eat a high-protein, high-calorie, high-vitamin diet to enhance resistance for tissue repair. At the same time, basic care should be strengthened to prevent pressure ulcers and the hospital to perform daily air disinfection and regularly open windows for ventilation.