فیستول شریانی یا AVF، اتصال غیر طبیعی عروق در بافت‌های اطراف مغز یا نخاع است که در آن یک یا چند شریان به طور مستقیم به یک یا چند رگ و یا فضاهای وریدی به نام سینوس متصل می‌شوند. شریان‌ها خون را از قلب به بافت‌ها حمل می‌کنند و رگ‌ها خون را از بافت به قلب می‌برند. در صورت وجود AVF، یک ارتباط مستقیم بین یک یا چند شریان و رگ یا سینوس وجود دارد که موجب مشکلات بسیاری می‌شود.

فیستول‌های شریانی با ناهنجاری‌های شریانی (Arteriovenous Malformation) متفاوتند، AVM در داخل بافت مغز یا نخاع یافت می‌شود، اما AVF در پوشش مغز یا نخاع، مانند سخت شامه یا آراکنویید یافت می‌شوند. جدی‌ترین مشکل مربوط به AVF این است که خون شریانی با فشار بالا را به رگ یا سینوس‌های وریدی انتقال می‌دهند که خون را از مغز یا نخاع تخلیه می‌کنند. این امر باعث افزایش فشار روی سیستم وریدی در اطراف مغز یا نخاع می‌شود.

دلایل فیستول شریانی

کاتتریزاسیون قلبی

فیستول شریانی ممکن است به عنوان یک عارضه از روشی به نام کاتتریزاسیون قلبی ایجاد شود. در طی کاتتریزاسیون قلبی، یک لوله بلند و نازک به نام کاتتر به داخل شریان یا رگی در کشاله ران، گردن یا بازوی شما وارد می‌شود و از طریق رگ‌های خونی به قلب شما وارد می‌شود.

اگر سوزن مورد استفاده در کاتتریزاسیون، در طی عمل جراحی از شریان و ورید عبور کند و شریان گشاد (بزرگتر) شود، می‌تواند فیستول شریانی ایجاد کند. این اتفاق به ندرت رخ می‌دهد.

آسیب‌هایی که پوست را سوراخ می‌کند

همچنین ممکن است پس از یک آسیب سوراخ کننده پوست، مانند گلوله خوردن یا زخم چاقو، فیستول شریانی ایجاد شود. این وضعیت ممکن است زمانی اتفاق بیفتد که زخم شما در بخشی از بدن ایجاد شده که یک رگ و شریان در کنار آن قرار دارند.

فیستول مادرزادی

بعضی از افراد با فیستول شریانی متولد می‌شوند (مادرزادی). Although the exact cause is not known, in congenital arteriovenous fistula, the arteries and veins do not form properly in utero

Genetic diseases

An arteriovenous fistula in the lungs (pulmonary arteriovenous fistula) can be caused by a genetic disease (Osler-Weber-Randow disease, also known as hereditary hemorrhagic telangiectasia) that causes the vessels to form Abnormal blood in the body, especially in the lungs.

Creation of surgical fistula

People with advanced kidney failure may also have an arteriovenous fistula, which is surgically created to make dialysis easier. If the dialysis needle is inserted too many times into the vein, the vein may be injured and destroyed. Creating an arterial fistula, by connecting the vein to an adjacent artery, widens it, making it easier for the needle to enter for dialysis and leading to faster blood flow. This AV fistula usually occurs in the forearm.

Symptoms

Small arterial fistulas in the legs, arms, lungs, kidneys, or brain often have no symptoms and usually do not require treatment except for a doctor's supervision. Larger arteriovenous fistulas can cause signs and symptoms.

Signs and signs of an arteriovenous fistula may include:

• Purple-colored raised veins, which you can see on your skin, that look like varicose veins
• Swelling in the arms or legs
• Low blood pressure
• Fatigue
• Failure Heart

When to see a doctor

If you have any of these signs and symptoms and think you may have an arteriovenous fistula, make an appointment to see your doctor. Early detection of an arteriovenous fistula can make your condition easier and reduce the risk of complications such as blood clots or, in severe cases, heart failure. Complications If an arteriovenous fistula is left untreated, it can cause complications, some of which may be atmospheric. These complications include:

heart failure

This condition is the most serious complication of a large arterial fistula. Because your blood flows faster through the arteriovenous fistula than through normal arteries, capillaries, and veins, your heart has to pump harder to compensate for the drop in blood pressure (called high-output heart failure). Over time, increased heart pumping can weaken your heart muscle and lead to heart failure.

Blood Clots

Arterial fistulas in the legs may cause blood clots to form, so that if the clot travels to the lungs, it can lead to deep vein thrombosis (pulmonary embolism), a potentially fatal condition. Depending on where your fistula is located, it can lead to a stroke.

Leg pain

An arterial fistula in your leg can also cause pain in your legs (lameness), or it can worsen existing pain.

Bleeding

Venous malformations may lead to bleeding, including in the digestive system.

Diagnosis

To diagnose an arteriovenous fistula, your doctor will use a stethoscope to listen to blood flow through an area he thinks may have a fistula. Blood flow through an arteriovenous fistula makes a ticking or whirring sound.

If your doctor hears a car sound, you will have other tests to confirm that the sound is caused by an arteriovenous fistula. These tests can include the following:

Duplex ultrasound

Duplex ultrasound is the most effective and common way to check for arteriovenous fistula in the blood vessels of the legs or arms. In a duplex ultrasound, a device called a transducer is pressed against your skin in the suspicious area.

This transducer produces high-frequency sound waves that bounce off red blood cells. A duplex ultrasound can estimate the speed of blood flow by measuring the amount of change in its step (frequency).

Computed tomography angiogram

A CT angiogram allows your doctor to examine your arteries and see if blood flow is bypassing the capillaries. You'll receive an injection of dye that will show up on the CT images, and the donut-shaped CT scanner will be moved to take pictures of the artery that your doctor believes is narrowed. Images are then sent to a computer monitor for your doctor to view. alt="" width="800" height="298" data-lazy-src="https://dreshraghi.com/wp-content/uploads/2020/05/arterial-venous-fistula-3.jpg">

Magnetic Resonance Angiography (MRA)

If your doctor thinks you may have an arterial fistula in an artery deep under your skin, he may use an MRA. This test allows your doctor to see the soft tissue in your body. It uses a technique similar to magnetic resonance imaging (MRI), but it also involves the use of a special dye that helps create images of blood vessels.

During an MRI or MRA, you lie on a table inside a long tube-like machine that produces a magnetic field. An MRI machine uses a magnetic field and radio waves to create images of your body's tissues. Using the images from this test, your doctor may be able to see the arteriovenous fistula.

Treatment

Your doctor may be able to detect your arteriovenous fistula just by looking, especially if it is small and does not cause any health problems. Some small arteriovenous fistulas will narrow without treatment.

If your arteriovenous fistula needs treatment, your doctor may recommend the following:

Surgery

The surgical treatment your doctor recommends depends on the condition of the arteriovenous fistula and your medical history, but generally it will be one of two types of surgery: catheter embolization or resection. Microsurgical.

The therapeutic goal of both methods is generally the same: to stop blood flow through an arteriovenous fistula, which is an abnormality in the circulatory system.

Embolization

One treatment option is called catheter embolization. A neurosurgeon or intracranial radiologist makes an incision near the groin on the top of the inner thigh to access an artery. Then a catheter is inserted into the artery and placed in the right place with the control of the graph. He uses an image guidance system to guide the catheter to the site of the arteriovenous fistula. Then he injects a substance called an embolic agent, which mainly stops the blood vessel and prevents blood flow from the malformed areas. The embolic agent may be a glue-like substance or something called onyx. During this arteriovenous fistula repair procedure, you will usually be put under general anesthesia to increase your comfort and allow the surgeon to perform the procedure.

Your recovery begins with catheter embolization in the hospital, where you should expect to be hospitalized for a day or two after the procedure. Immediately after the procedure, you may be asked to lie flat for about six hours, but after that you can sit and walk if you are ready. During this time, your doctor will monitor your incision to check for bleeding or swelling and watch for any complications from your embolization procedure.

Recovery at home can vary from a few days to a few weeks, depending on your overall health and other factors. During the first days of recovery, activities such as driving, exercising, and lifting heavy objects should be limited and you should get plenty of rest. Doctors may prescribe medications for pain and other problems. You should check the incision site on the inside of your thigh for signs of infection and bleeding, although this incision site is usually uncomplicated.

You can gradually resume your normal activities over the next week or so. In the weeks following catheter embolization, you are expected to have follow-up appointments with your doctor to review the healing of your incision and the outcome of your procedure. Some people also require multiple embolization procedures over time, called staged embolization.

This procedure is considered a minimally invasive procedure and is a means for the neurosurgeon to access the arteriovenous fistula indirectly. However, it is not suitable for all patients, as some arterial fistulas can be closed using an embolic agent.

Microsurgical Excision

Some patients are not good candidates for catheter embolization, so your doctor may suggest another method called microsurgical resection to repair the arterial fistula. Microsurgery is surgery that is performed under a special microscope that allows the surgeon to have a better view when performing delicate procedures. Thanks to this advanced technology, neurosurgeons can perform surgeries that were previously difficult or even impossible.

During this procedure, your neurosurgeon directly accesses the arteriovenous fistula to repair it. The neurosurgeon needs a craniotomy (opening the skull) to access the blood vessels. This means that they remove a small part of the skull and have direct access to the site of the deformity.

However, depending on the situation and circumstances, not all patients need a craniotomy. Not all arteriovenous fistulas occur around the brain, and even those that do can be accessed through incisions made elsewhere. As with catheter embolization, with microsurgical resection, you must be under general anesthesia.

Recovery from microsurgery to remove an AVF depends on many factors, including age, health, and the location and size of the fistula. Although in general, you can expect to stay in the hospital for about 3-5 days while the care team; They will monitor your recovery from anesthesia and the healing process of the incision and check for any complications from the procedure.

Recovery at home can take several weeks, usually six weeks, but your recovery will vary according to your condition and condition, as all patients are different. Doctors will give you specific instructions on how to care for your incision after you go home. You are expected to be restricted from driving, lifting, and vigorous activity for a week or so, and will gradually return to normal activities over the next few weeks.

During this time, you may feel tired and sore, so doctors may prescribe medications to help you recover. If your surgery involves the brain, you may experience temporary neurological problems, such as difficulty concentrating or problems with coordination or balance. Within a few weeks after surgery, you can expect to see your doctor for follow-up appointments to remove stitches and check for improvement. meet You can return to work after six weeks.