Overview of Fasciocutaneous Flaps
Fasciocutaneous flaps, also known as axial flaps, are made up of skin, fat underneath the skin (known as subcutaneous tissue), and a deeper layer called the fascia. They do not contain any muscle tissue. These flaps may have better looks and function compared to flaps that comprise muscle only or muscle and skin. This is due to the thin and flexible nature of the tissue that is being transferred.
In 1981, Pontén began to use fasciocutaneous flaps to reconstruct the legs. His work highlighted the importance of including the deep fascia in flaps for the leg. This was a change from the usual approach of only using blood supply from under the skin’s surface. Pontén also found that using a fasciocutaneous flap allows more flexibility in the shape and size of the flap. This expands the options for reconstruction while reducing the risk of skin death.
Since then, fasciocutaneous flaps have become a popular option to cover bones and tendons in the lower leg and other parts of the body. Further research has shown the importance of including the fascia, as it protects the blood vessels in the flap and improves the survival of the flap.
Over the years, other researchers expanded the uses for these flaps and refined the understanding of their anatomical structure. Despite newer techniques, fasciocutaneous flaps are still a beneficial option due to their simplicity and reliability. They can also serve as a backup option when other techniques do not work.
Anatomy and Physiology of Fasciocutaneous Flaps
The transportation of blood to the skin and fascia flaps (a type of tissue used in plastic and reconstructive surgery) depends on specialized vessels known as fasciocutaneous perforating vessels. These vessels move up through your skin from a meshwork of vessels just below your skin’s surface, known as the suprafascial plexus. There’s also a less developed system of vessels between the layer of tissue under the skin called the fascia and the muscle below, known as the subfascial plexus. In addition to these, there are also blood vessel networks in the top layers of your skin, the dermis and directly below it, the subdermis.
These multiple networks of vessels receive blood from arteries that penetrate the deep tissue beneath the skin, which get there either through the muscles (musculocutaneous perforators), through the walls separating muscles (septocutaneous perforators), or directly from skin branches. Cutting through the subfascial plane is easier than cutting through the suprafascial plane when preparing the flap for surgery.
Studies by Cormack, Lamberty, Pontén, Tolhurst and others have shown that the setup of this blood vessel system can vary depending on the region of the body. For instance, vessels referred to as septocutaneous play a crucial role in supplying blood to the vessel network under the skin’s surface in the arms and legs, whereas the main source of the blood supply in the chest and belly comes from arteries penetrating the muscles.
Why do People Need Fasciocutaneous Flaps
Fasciocutaneous flaps are a type of skin graft that doctors use when a wound is too large to heal on its own or to be closed up directly. Some other options include things like perforator-based or free flaps, but fasciocutaneous flaps are often the quickest and easiest solution. These grafts are thin, easy to move, and can be taken from many different parts of the body. They keep the main blood supply of the area where they are taken from intact. Unlike some other types of grafts that are more bulky, fasciocutaneous flaps usually don’t cause any big changes or problems in the area they’re taken from.
Even though people used to think these grafts were more likely to get infected because they don’t have as much blood supply as some other types, recent research has shown that they’re just as good as the others when it comes to dealing with infected wounds. This finding changes the way we think about these grafts and shows they can be a very useful tool.
Fasciocutaneous flaps are especially useful when a doctor has to redo a surgery and needs to cover a certain area with skin. They’re great for parts of the body that have thinner skin, like the lower leg, the back of the hand, the nose, and the mouth and throat. These grafts can be used to rebuild a large amount of the soft tissue without needing to delay the surgery to prepare the graft. However, they’re generally not used for deep wounds, where other types of grafts that can provide more volume might be better.
There are four main types of fasciocutaneous flaps, each with different blood supplies. Some get their blood from multiple little blood vessels at their base, while others get it from a single blood vessel or a number of small ones coming from a main artery. Some of them include adjacent muscle and bone.
The way a fasciocutaneous flap is harvested – or taken from the body – depends on things like the size and location of the wound that needs to be covered, what kind of tissue is available to be used, and what the patient wants it to look like in the end.
There are four configurations for how these flaps can be harvested. One involves keeping the flap attached to its original site at one end, so it can be rotated or moved like a hinge. But sometimes this can leave a bulky lump that might need another surgery to fix. Another involves separating the blood vessel supply from the actual flap but keeping them connected, which allows the flap to be moved more freely. There are also versions that include subdermal fat and the fascia underneath it, or just the fascia on its own.
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These flaps were first used mainly in surgeries to reconstruct parts of the leg. Different designs are used for different parts of the leg, and they can be taken from the back, side, or front of the leg, either from the top or bottom. If a flap is taken from lower down the leg, there’s a higher chance of blood pooling there, but this can be lessened by connecting a vein in the flap to one in the area being treated. The blood supply for these flaps comes from several different arteries depending on where exactly on the leg the flap is taken from, and the veins draining the blood away follow the same path as the arteries.
What’s most important here is making sure that the flap has a good enough blood flow to keep the tissue alive. This means picking a good vascular pedicle (the blood vessel that feeds the graft) rather than sticking to a set ratio of length to width. Using this approach allows doctors to narrow the base of the pedicle, which makes it possible to take a real island flap.
There are various types of fasciocutaneous flaps that can be used depending on the specific case and what is needed. For example, the flap can be based at the top, i.e., closer to the heart, or at the bottom, i.e., further from the heart.
In conclusion, there are many factors to consider when a doctor decides to use a fasciocutaneous flap. The right choice of graft will depend on various factors, and can greatly help in the patient’s healing or reconstruction process.
When a Person Should Avoid Fasciocutaneous Flaps
There are several reasons that may prevent a person from undergoing a certain type of skin graft surgery called fasciocutaneous flap surgery. One major reason could be a lack of suitable skin to transfer. Various factors can make skin unfit for this purpose:
- The skin area isn’t big enough to cover the wound.
- Scars or shrinkage from previous injuries or surgeries damage the skin.
- The blood supply to the skin flap is hampered. This could be because of damaging an artery, causing swelling due to fluid accumulation (lymphedema), or due to an underlying issue with your blood vessels (vasculopathy).
It’s noteworthy that smoking can be unfavorable for this surgery. Smoking can impair small blood vessels in your skin, which is essential for the skin graft’s survival. Therefore, smoking is ideally avoided leading up to the surgery. Thankfully, even stopping smoking for just one week before surgery can considerably enhance the chances of a successful skin graft. If a patient can’t quit smoking, other reconstructive options may be advisable. For instance, a thicker skin flap from a muscle can be used, though it will add bulk.
Diabetes is another common cause of compromised blood vessels that might disrupt the success of the skin graft. Consequently, before the surgery, people with diabetes or who are suspected to have blood vessel problems need a thorough check-up. Various imaging techniques can be used in this assessment to evaluate the potential success of the graft and to consider alternatives if needed.
Fasciocutaneous flaps are generally unsuitable for treating complex injuries involving different types of tissues, where a plumper flap from a muscle might be more useful.
Another factor to think about is the wound’s size. Some flaps might not be sufficient to cover the wound fully, and the area from wherever the flap is taken might need additional skin grafting.
In the end, patients should be aware of all possible risks before the surgery and have the flexibility to make their own treatment decisions. In some cases, they may still prefer to proceed with the skin graft without giving up smoking, understanding the associated risks.
Equipment used for Fasciocutaneous Flaps
Before the operation
* An alcohol solution or pad is used to clean the skin.
* A surgical marker is used to mark the area where the procedure is to be done.
* Local anesthetic (for example 1% lidocaine with 1:100,000 epinephrine) in a 10 mL syringe with a 27 gauge 1.5-inch needle or something similar is used to numb the area.
* Topical antiseptics like chlorhexidine or povidone-iodine help to kill or slow down the growth of bacteria on the skin.
* A sterile surgical drape is used to cover the patient and keep the area clean.
During the operation
* A scalpel (#15 blade) is used to make an incision in the skin.
* Forceps (like Gerald, DeBakey, and Adson) help to hold tissue or other instruments.
* Dissecting scissors (like Shea or Metzenbaum) are used to cut tissue.
* Suture scissors (like Iris or Mayo) cut the sutures (material used to close a wound or incision).
* Gauze is used to absorb blood and other fluids.
* Monopolar or bipolar electrocautery are tools that use heat to stop bleeding.
* Joseph skin hooks and Senn retractors hold the skin and tissues back to give the surgeon a clear view.
* Needle drivers help to hold the needle when sewing up the wound.
* Normal saline rinses and cleans the area.
* Suture (for example, 2-0 braided polyglactin, 2-0 or 3-0 poliglecaprone, 3-0 polypropylene or nylon) is used to sew up the wound.
After the operation
* Petrolatum ointment is applied to soothe and protect the wound.
* Nonadherent gauze covers the wound to absorb any fluids and to protect it.
* Gauze roll is used to wrap and secure the wound.
* Surgical tape holds the gauze and dressings in place.
Who is needed to perform Fasciocutaneous Flaps?
The main people who perform skin and tissue transplant surgeries (called fasciocutaneous flap transfers) are usually plastic surgeons. However, other kinds of surgeons, like those focusing on bone injuries (orthopedic trauma surgeons) or hand issues, are also trained to do these surgeries. In the case of difficulties in the head and neck, some specific surgeons like cancer surgeons, reconstruction surgeons (who fix or adjust parts of the body), and facial plastic surgeons also know how to handle these techniques.
Beyond the main surgeon, there’s also a second person called an assistant, who helps during surgery by holding tools, cutting stitches, and keeping any bleeding under control. A surgical technician and a circulating nurse (a nurse who works in the operation room) are also crucial members of the team. These surgeries can be carried out either under general anesthesia (you are fully asleep) or regional anesthesia (only a certain part of your body is numb), depending on what’s best for you and the part of the body that’s affected by the surgery. So, a professional who administers these types of anesthesia is usually needed too.
Preparing for Fasciocutaneous Flaps
Before undergoing surgery, it’s important for patients to understand what the procedure involves, the possible complications and the potential results. There could be some complications, such as reduced blood flow that could harm tissue, and there might be cosmetic changes that the patient is not satisfied with. Both the spot where the tissue was taken and where it was placed (the flap) could require further operations.
It’s important that patients stop smoking at least a week before the surgery. This is key for optimizing blood flow in the flap, which helps with healing. If any care is needed after the surgery, like if drains are placed or any complications arise that require particular wound care, the patient will be taught how to handle this after the operation.
The preparation for the surgery involves designing a ‘flap’ – a piece of skin with its own blood supply – that fits the area where it’s needed. By creating a flap that is slightly bigger than needed, the doctors can ensure enough coverage even when there’s a bit of a shrinkage when the flap is rotated and settled into place. This extra size also reduces pressure when the wound is closed up, and protects the blood supply to the end of the flap.
In cases where the surgery is performed on an arm or a leg, a tight band (a tourniquet) could be used to reduce bleeding and make the surgery site clearer to see. However, this can only be used for a maximum of two hours to ensure the safety of the patient.
It’s also critical to position the patient in a way that allows the surgical team to easily access the surgery site. This should be done while preventing unnecessary pressure points and nerve strain, keeping in mind the likely length of the surgery. After positioning the patient appropriately, local painkillers might be used if required, and the surgical site will be thoroughly cleaned with an antiseptic solution to minimize the risk of infection.
How is Fasciocutaneous Flaps performed
In simple terms, fasciocutaneous flaps are sections of skin and tissue, alongside their blood supplies, which are moved from one area of the body to another to treat various types of wounds. This procedure becomes quicker and easier with practice. The way these flaps are designed and placed depends on where your wound is and which area of your body will provide the tissue for these flaps.
Before cutting the skin, it’s key to pinpoint a ‘pivot point’ — this is where the tissue is attached to its blood supply. The surgeon also needs to establish how long the pedicle, or attached stalk of the flap, should be. Remember that when these flaps are rotated into the wound, their length gets reduced because of the rotation. The degrees of rotation and the reduction in length have a specific relationship: a 45° turn reduces length by 5%, a 90° turn results in a 15% drop, and a 180° spin causes a 40% decrease. The nature and size of the wound at the base of the skin flap also impact how much it can be rotated.
Usually, a surgeon will cut through the skin, tissue beneath the skin, and a layer of fibrous tissue called fascia. When lifting the flap, they will work within a layer below the fascia, to protect the small blood vessels supplying the skin. These blood vessels don’t need to be individually identified, but the surgeon should take care to protect the blood vessels in the stalk that feed the skin flap.
The skin around the wound is then removed, and the edges of the wound are loosened. The skin flap is then moved into place and stitched securely to provide stability. The skin is then closed around the edge of the skin flap. If large flaps are being rotated, any other skin defects should be addressed later as removing them at the same time could disrupt blood flow to the skin flap. The wound left behind when the flap was removed can be quickly closed with a piece of skin from another part of the body; however, because it’s usually uneven, it might be best to let healthy granulation tissue, or new skin, to develop before applying the graft. After the surgery, the area is bandaged firmly, and if necessary, continuous suction drainage may be used for a day or longer if there’s ongoing bleeding.
Possible Complications of Fasciocutaneous Flaps
The biggest worry after a fasciocutaneous flap transfer surgery—the procedure where a part of your skin and tissue is moved from one place to another—is something called vascular compromise. This can lead to the transplanted flap not getting enough blood, which could cause it to partially or fully die off. This issue can be due to problems with your arteries or veins.
Arterial insufficiency is when your arteries can’t carry enough blood. This might happen if you are a smoker or a diabetes patient, or if there’s too much strain on the flap, causing the tiny tubes carrying blood to and from the flap to get tight. Also, if your blood pressure drops too low, or if a clot forms in your arteries or veins, there can be a blood supply problem. Venous insufficiency is more common and happens if the flap is lifted without enough ways for blood to flow out or if something is blocking the blood from leaving, like a blood clot forcing pressure on the vein or the vein getting twisted. Doing a delicate surgery on a vein in the flap to attach it to a vein in the wound can help blood flow more smoothly and decrease the chance of flap failure.
Additional risks with this surgery include not being happy with how the flap looks because its color, texture, or hair growth doesn’t match with the surrounding skin, possible scarring or changes at the place from where the flap was taken, especially if it’s a big flap. While normal hair and oil gland functions usually come back to the flap after the transfer, you might feel less sensation there in the long run. Plus, the usual risks of any surgery, such as pain, bleeding, infection, and damage to body structures near where the flap is lifted, exist, which might require more surgeries.
What Else Should I Know About Fasciocutaneous Flaps?
Fasciocutaneous flaps are a key method doctors use in reconstructive surgery to mend larger wounds that can’t be closed normally. They are special type of tissue in our body that includes the deeper layer of skin known as fascia and its surrounding blood vessels. They provide better wound coverage compared to other techniques, especially for injuries on the lower limbs.
These flaps are known for being thin, flexible, and easy to lift and move around. They are capable of treating a variety of wounds, and are particularly good at covering exposed tendons, bones and joints.
Even with newer techniques available in reconstructive surgery, fasciocutaneous flaps are still highly valued because they are reliable and simple to apply. Surgeons often turn to them when other techniques, such as perforator-based flaps (a type of tissue flap that includes small blood vessels), or free flaps (tissue taken from one location of the body and moved to another), aren’t successful.
