Overview of Axial Flaps
An axial pattern flap is a type of skin graft in a plastic surgery that uses a specific blood vessel in its design. Thanks to this direct blood supply to the skin, a large area of skin can be moved almost instantly, rather than having to do it in stages, which was the standard practice before. In the past, random pattern flaps were prepared over time to improve blood circulation to the new area of skin.
There are several advantages to using an axial pattern flap. For example, there’s no need to prepare it over a longer period of time, the skin transferred is thick and sturdy, and the end result generally looks quite good. Moreover, research has revealed that the survival rate of these flaps—that is, the success rate of the surgery—is significantly higher compared to flaps that don’t have a direct blood supply. In fact, studies have found that 95% of axial pattern flaps survive, as compared to only 53% of flaps without a direct blood supply.
Several types of axial pattern flaps include nasolabial flap off of the angular vessels, Paramedian forehead flap off of the supratrochlear vessels, facial artery musculomucosal flap, and melolabial flap.
Anatomy and Physiology of Axial Flaps
Knowing the workings of our skin is necessary to understand how certain operations involving ‘flaps’ of skin work. ‘Flaps’ in this context refer to sections of skin that are moved from one part of the body to another. There are two main networks of blood vessels—the deep and superficial vascular plexus—that provide blood to the skin. These blood vessels not only provide nutrients to the skin, but also help control body temperature. The survival of these ‘flaps’ depends on these blood networks.
There are four basic types of skin flaps: random, axial, reverse flow axial pattern flaps, and island flaps. Random flaps are reliant on the deep vascular network (subdermal plexus), which is fed by unnamed small blood vessels that pass through muscles and skin. Axial pattern flaps, on the other hand, receive their blood supply directly from a specific artery, which runs beneath them. These arteries fuel the deep vascular network and ensure the flap gets enough blood. However, areas of the skin flap that lie beyond the direct reach of this artery, depend on the two skin blood networks, same as the random flaps.
‘Reverse flow axial pattern flaps’ are a special type of axial flap for which the primary blood supply is cut off near its origin. Thus, the blood has to flow backward through the blood vessels in the more distant parts of the flap. Lastly, ‘island flaps’ are a kind of axial flap too, but they differ in that they are lifted on a stalk of tissue without skin, allowing them to be moved to a far-off location on the body.
Why do People Need Axial Flaps
If you have a large wound because of an injury or after having a mass removed, you might need a special type of skin repair called an axial flap. An axial flap involves taking skin from one area of your body and moving it to the wound site. The area where the skin is moved to should be clean and free from infection, but it doesn’t necessarily need to have granulation tissue (new vein-rich tissue that forms after an injury).
The good thing about axial flaps is that they come with their own blood supply, so they don’t need a blood supply at the new location. This is different from skin grafts which require a blood source in the new place where they are moved to work properly.
There are quite a few advantages to using axial flaps for wound repair. These include being able to move larger pieces of skin compared to other treatments, covering the entire thickness of the wound with skin, using very tough skin that holds up well to use, and giving you really good-looking results.
Due to the reliable blood supply in these flaps, they can provide strong, full-thickness skin coverage. This can result in less scar tissue formation and possibly even restoring hair growth close to how it was before.
When a Person Should Avoid Axial Flaps
There are certain situations where a specific kind of skin graft, called axial flaps, may not be suitable for some patients. For example, if a patient has an active infection at the site where the graft will be placed, it’s not safe to proceed. The same holds if the “stalk” of the graft (the pedicle) is damaged or if the wound wasn’t properly cleaned.
Some conditions make this type of skin graft riskier. For instance, if a patient is a smoker, it’s more likely the grafted skin might die. This is because smoking can reduce the blood flow which the grafted skin needs to survive.
Additionally, it is generally advisable to avoid using an area of skin for grafting if it has been previously exposed to radiation. This is because radiation can damage the skin, making it less likely the graft will be successful.
Equipment used for Axial Flaps
An axial flap is a type of skin graft that doesn’t need any specialized equipment. It’s simpler than a procedure known as microvascular free transfer, which is a more complex type of skin graft. The tools used for an axial flap are usually the same ones used for other similar procedures, known as regional and local flap surgeries. A Doppler, which is a device used to measure blood flow, can be handy for locating the blood vessels and tiny arteries (known as perforators) involved in this procedure.
Who is needed to perform Axial Flaps?
The process of creating axial flaps, which is a method to repair skin or tissue, can be effectively performed with only one additional helper for the surgeon. This assistant helps with several tasks during the surgery. They help pull back the skin or tissue (retraction), stitch up the wounds (suturing), perform cuts (cutting), and stop any bleeding during the operation (achieving hemostasis).
Preparing for Axial Flaps
Before you have surgery, your doctor will examine your skin closely. He’s checking for things like thick, colored scars or growths called keloids. Your doctor is doing this to make sure he can do the surgery safely and to warn you about any possible issues before the operation.
They will also pinch the skin where the operation will take place. This helps them know if they can close the wound easily after the surgery. They might use a handheld tool to listen to the blood flow in the arteries in the area of the surgery. This helps them make sure the blood flow is good, which is important for the surgery and healing.
It’s important that you talk with your doctor about all the risks and benefits of the surgery, as well as any other treatment options. They will explain everything about the surgery, which is called “axial flaps”.
If you’re an older person, it’s worth noting that there’s a greater chance that the skin might not survive where they do the surgery compared to younger people. This is because as we age, the small blood vessels in our skin can change, become less organized or not be there at all, which can affect the surgical outcome.
How is Axial Flaps performed
When a surgeon plans to make an initial cut on your skin, they keep in mind the natural lines and tensions of your skin. Relaxed skin tension lines (RSTL) are the natural lines in our skin that form due to the various movements of our body and the direction of the underlying muscle fibers. The tension of skin is usually highest along these lines, while it’s lowest along the lines that can be extended the most. To make sure the cut heals properly and leaves minimal scars, the cut is usually made along the lines of the skin’s natural tension. These natural lines are also called Langer’s lines.
Sometimes, for areas like your trunk, neck, or the part of your limbs closer to your body, a special procedure called axial flaps might be needed. This is usually done when there’s enough flexible skin available. In this process, a piece of skin is moved from one part of your body to another, while keeping its blood supply intact. Here’s a simple way to understand how it’s done:
- The surgeon first measures the part of your skin that needs to be repaired.
- Next, they mark a section of your skin (called a skin paddle) that will be used to repair the damaged area. This skin will be supplied by a blood vessel (the vascular pedicle), which is kept in mind while marking the skin area. The surgeon also ensures that they maintain the route of blood vessels within the fat layer under your skin.
- To keep the blood supply safe, the surgeon will typically leave a small cushion of tissue and fat around it. They do not need to see the blood supply during this procedure. However, if something suggests that there’s a problem with the blood supply for the flap, they might need to expose and protect the blood vessels (this is called vessel skeletonization).
- After that, the skin flap is transferred to the area that needs to be fixed.
The skin flap is then carefully tucked in the area that needs to be fixed. Afterward, the area of the skin from where the flap was taken, called the donor site, is closed. This can be done directly or sometimes using skin grafts (transplanting a thin layer of skin), based on how big the initial damaged area was.
Possible Complications of Axial Flaps
There are several risks that can occur with an axial flap, which is a type of skin graft. These include:
1. Seroma formation: This happens when a pocket of clear bodily fluid, known as seroma, develops in the area where the surgery was done.
2. Wound drainage: This is when fluid leaks out of the wound after the surgery.
3. Donor site dehiscence: This refers to the separation or burst open of the wound at the place where the skin graft was taken from, also called the donor site.
4. Distal flap necrosis: This means that the tissue in the far end of the skin graft dies.
5. There could also be issues where the wound takes a longer time to heal, or it doesn’t heal fully. It is also possible to experience venous congestion, which means that the blood flow goes back and accumulates in the veins instead of flowing normally. This may need additional procedures to relieve pressure or to move the skin graft back to its original spot to help it get more blood supply.
What Else Should I Know About Axial Flaps?
If you have a large wound or damaged skin area, a treatment called “axial flaps” might be used. This method takes a piece of skin, along with its blood vessels, from one area of your body and moves it to the damaged area. It’s a relatively straightforward procedure that can fix the problem in one step, which is easier than having multiple surgeries.
This technique is very useful for treating large skin damages that might be tough or even impossible to fix otherwise. Not only does it heal the wound, but it also makes the skin strong and helps it look better – a great plus for your appearance. So, if you have a large wound or skin defect, axial flaps might be a good option for you.
