Arteriovenous fistulas (AVFs) are pathological or surgical vascular connections between arteries and veins. They can be congenital or acquired defects, for example after a penetrating trauma or an aneurysmal rupture. The symptomatology depends on the location and regional anatomy of AVF. Surgical AVF is used for long-term vascular access in hemodialysis.

Usually, acquired AVFs lead to a mass that can be palpated, transmits pulses, and a bruit can be heard during auscultation. These masses are commonly observed in an extremity previously affected by a significant traumatization. Symptoms of high-output congestive heart failure may also be reported, most frequently if the flow via the AVF is greater than 1/5 of the cardiac output, and include peripheral edema, cough, fatigue, shortness of breath, and ascites [1].

AVFs may lead to serious complications such as hemorrhage and neurological impairment [2].

With regard to congenital AVFs, the region where they are formed dictates the symptomatology. More specifically:

• AVFs in extremities

Symptoms may fail to arise for years after the patient is born. Similarly to acquired AVFs, congenital AVFs located on the extremities induce peripheral edema and hypertrophy of the extremity in young patients. This manifestation is aggravated when the AVF is found in the lower part of the extremity [3]. The clinical picture may be further complicated with the onset of ulcers, thromboembolic events, and cardiac failure [4] [5].

• Intracranial AVFs

Typical symptoms of intracranial AVFs include a headache, ocular deficits, and neurological symptoms that are usually not significant. Some patients may remain asymptomatic.

• Pulmonary AVFs

A considerable number of patients presenting with pulmonary AVFs are also diagnosed with vascular anomalies in the nasopharynx, liver, spleen and gastrointestinal tract, as manifestations of the Rendu-Osler-Weber syndrome. Pulmonary arteriovenous fistulas per se may lead to dyspnea on exertion, symptoms related to high-output congestive heart failure, pulmonary hypertension, and hypoxemia [6] [7]. Compensatory polycythemia may develop, leading to non-specific symptoms, such as a headache and fatigue.

• Spinal AVFs

They can lead to manifestations related to myelopathy.

• Hepatic AVFs

These AVFs can be related to Rendu-Osler-Weber syndrome, Ehlers-Danlos syndrome, and biliary atresia.

• Femoral AVFs

Patients frequently have varicosities. Symptoms associated with diminished perfusion of the limb can also arise.

• Congestive Heart Failure

  Pulmonary arteriovenous fistulas per se may lead to dyspnea on exertion, symptoms related to high-output congestive heart failure, pulmonary hypertension, and hypoxemia. [symptoma.com]

  None of the patients developed symptomatic steal syndrome or congestive heart failure. Five of 6 patients had successful usage of the new AVF, and subsequently underwent ligation and excision of the aneurysmal AVF, thus avoiding a temporary HDC. [ncbi.nlm.nih.gov]

• Hypoxemia

  Pulmonary arteriovenous fistulas per se may lead to dyspnea on exertion, symptoms related to high-output congestive heart failure, pulmonary hypertension, and hypoxemia. [symptoma.com]

• Hypertension

  The insertion of the cAV coupler resulted in a sustained anti-hypertensive effect nine months post-procedure, with mean 24-hr ABP of 154/91 mm Hg on only two anti-hypertensives. [ncbi.nlm.nih.gov]

  Instead, we performed thoracic spine MRI to rule out the possibility that residual AV shunting was causing recurrent venous hypertension and cord hypoperfusion. [surgicalneurologyint.com]

• Heart Failure

  Both patients had undergone abdominal surgery several years prior to the heart failure event with the initial finding of moderate pulmonary hypertension and high-output heart failure. [ncbi.nlm.nih.gov]

  Heart failure occurs when the heart is unable to pump the blood that it receives. We will limit our discussion to left ventricular failure. [web.archive.org]

• Vascular Disease

  The controls were randomly selected from uremic patients who were primary AVF operation, excluded obvious vascular stenosis and vascular diseases. Among them, 4 sample in the experimental group and 4 controls were used in LncRNA sequencing. [ncbi.nlm.nih.gov]

  Arteriovenous fistula, abnormal direct opening between an artery and a vein ; it sometimes results from accidental penetration wounds or from vascular disease, or it may be congenital in origin. [britannica.com]

  disease interventional cardiology A 62-year-old female underwent successful primary percutaneous coronary intervention for an acute anterior wall myocardial infarction via the right radial artery access. [heartasia.bmj.com]

  Renal Data System, USRDS 2007 Annual Data Report: Atlas of Chronic Kidney Disease and End-Stage Renal Disease in the United States, National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 2007 Dhingra [advancedrenaleducation.com]

• Cyanosis

  […] general Detect by xray Often multiple lesions, most commonly in right lower and middle lobe Probably congenital from persistent anastomotic fetal capillaries Shunting of blood between arterial and venous circulations may be asymptomatic or cause bruit, cyanosis [pathologyoutlines.com]

  This can determine a continuous murmur that is superficially heard and usually is associated with cyanosis and typical X-ray changes [ 9, 12 ]. [ncbi.nlm.nih.gov]

• Wide Pulse Pressure

  The physical manifestations of this would be a relatively normal systolic blood pressure with a decreased diastolic blood pressure resulting in a wide pulse pressure. [en.wikipedia.org]

• Fracture

  There are 2 forms: the carotid cavernous fistula, which typically occurs after a basal skull fracture; and the spontaneous dural cavernous fistula, which forms most often as a degenerative process in older patients with systemic hypertension and atherosclerosis [aao.org]

  The study aims to investigate the ability of maxillofacial surgery to reduce strabismus and improve ocular clinical symptomatology in patients with fracture of the medial or lateral floor of the orbit, or both, and to evaluate such abilities relative [giornalechirurgia.it]

• Kidney Failure

  Potassium, for example, increases in the blood during kidney failure and can cause heart irregularities. [surgeryencyclopedia.com]

  Dialysis is a common treatment for kidney failure. A dialysis machine acts as an artificial kidney and draws blood from your body, circulates and cleanses it, and then returns it to your body. [spectrumhealth.org]

  Surgical creation —People who have late-stage kidney failure may have an AV fistula surgically created to make dialysis easier. If a dialysis needle is inserted into a vein too many times, the vein can scar and be destroyed. [gmcimaging.org]

  This video explains how most people with kidney failure feel better after starting dialysis. To make the most of your hemodialysis treatment, keep to your ideal “dry weight.” [niddk.nih.gov]

  When patients suddenly discover they have kidney failure, a catheter may be placed to allow for immediate dialysis treatment. The catheter will be used until a fistula or graft has time to mature. [davita.com]

Radiological modalities employed in the diagnosis of arteriovenous fistulas are computed tomography (CT) angiography, magnetic resonance (MR) angiography, digital subtraction angiography (DSA), and color Doppler ultrasound.

CT angiography is a successful diagnostic procedure which produces accurate and specific findings. The modality reveals contrast material entering the vein prematurely during the arterial phase and illustrate the precise location of AVF. It has been found that CT angiography yields results that are in agreement with digital subtraction angiography [8]. The latter can provide particularly accurate information concerning the arteries involvement in the fistula formation and can help to create a diagram concerning the optimal therapeutic intervention.

Color Doppler ultrasound demonstrates blood flow patterns and velocity in the vessels. Frequent findings are an arterial-like wave in the adjacent vein and turbulent flow at the site of a connection. MRA is performed, in order to diagnose and clearly delineate the borders of AVFs [9] [10].

MR angiography could be performed in order to visualize AVFs more precisely [9] [10].

With regard to blood laboratory studies, patients affected by extensive AVFs may exhibit abnormal results such as thrombocytopenia, elevated PT and PTT time, decreased fibrinogen, and prolonged euglobulin clot lysis time.

KEYWORDS: Treatment; arteriovenous fistula; endovascular; evolution; intraorbital; pure [ncbi.nlm.nih.gov]

The best treatment strategy for subtype B is still being debated. [surgicalneurologyint.com]

Angiosarcomas developing in nonfunctioning arteriovenous fistulas in renal transplant recipients are quite rare clinical entities with very poor prognosis. [ncbi.nlm.nih.gov]

In our experience, most children have an excellent prognosis. [childrenshospital.org]

Prognosis With appropriate management and interventions, prognosis is generally very good with many patients reaching their 9th and 10th decades of life. During pregnancy, however, there is a 1% maternal death rate. [orpha.net]

A spontaneous vertebral-venous fistula is rare, and the 2 cases presented illustrate an underlying spontaneous etiology. The first patient presented with a spontaneous fistula, and the second case occurred in a patient with neurofibromatosis type 1. [ncbi.nlm.nih.gov]

[email protected]. 2 Department of Surgery, Leiden University Medical Center, Leiden, The Netherlands. 3 Department of Surgery, Haaglanden Medical Center, The Hague, The Netherlands. 4 Department of Clinical Epidemiology, Leiden University Medical [ncbi.nlm.nih.gov]

Summary Epidemiology Prevalence is estimated at around 1/ 2,600. There is a minor female predominance. [orpha.net]

The aim of the following article is to review the epidemiology, etiology, clinical and imaging features, and therapeutic approaches of this type of spinal vascular malformation. [ajnr.org]

We present the first case of a dAVF with radiographic evidence of severe cortical venous reflux into the subependymal venous network causing isolated intraventricular hemorrhage, thus lending proof for the underlying pathophysiology. [ncbi.nlm.nih.gov]

Early detection and surgical or endovascular intervention are important to preventing permanent neurologic impairment. Selective spinal angiography is still the gold standard for the diagnosis and localization of the SDAVF. [ncbi.nlm.nih.gov]

These actions can help prevent infection, bleeding, or damage to your AVF. [drugs.com]

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