Vein of Galen malformations are devastating complications. Studies have shown that 77% of untreated cases result in mortality. Even after surgical treatment, the mortality rate remains as high as 39.4%. Most cases occur during infancy when the mortality rates are at their highest. Vein of Galen malformations are a relatively unknown affliction, attributed to the rareness of the malformations. Therefore, when a child is diagnosed with a faulty Great Cerebral Vein of Galen, most parents know little to nothing about what they are dealing with. To counteract this, support sites have been created which offer information, advice, and a community of support to the afflicted (, ).

Head circumference measurements should be obtained regularly and monitored carefully to detect hydrocephalus. Neurosurgical procedures to relieve hydrocephalus are important. A ventriculoperitoneal shunt may be required in some infants. A pediatric cardiologist should be consulted to manage high-output failure, if present. Often patients need to be intubated. In most cases, the fistulous arteries feeding into the Vein of Galen must be blocked, thereby reducing the blood flow into the vein. Open surgery has a high morbidity and mortality. Recent advances over the past few decades have made endovascular embolization the preferred method of treatment. These treatments are preferred because they offer little threat to the surrounding brain tissue. However, there have been several reported cases of arteriovenous malformations recurring. The young age of many patients, the complex vascular anatomy, and the sensitive location of the Vein of Galen offer considerable challenges to surgeons. Another treatment option is Radiotherapy. Radiotherapy, also called radiosurgery, involves the use of focused beams to damage the blood vessel. Radiotherapy is often not pursued as a treatment because the effects of the procedure can take months or years and there is risk of damaging adjacent brain tissue.

Manual carotid self compression is a controversial treatment for DAVF. Patients using this method are told to compress the carotid with the opposite hand for approximately 10 minutes daily, and gradually increasing the frequency and duration of compression. Currently, it is unclear whether this method is an effective therapy.

For newborns with transposition, prostaglandins can be given to keep the ductus arteriosus open which allows mixing of the otherwise isolated pulmonary and systemic circuits. Thus oxygenated blood that recirculates back to the lungs can mix with blood that circulates throughout the body. The arterial switch operation is the definitive treatment for dextro- transposition. Rarely the arterial switch is not feasible due to particular coronary artery anatomy and an atrial switch operation is preferred.

The mainstay of treatment for CCF is endovascular therapy. This may be transarterial (mostly in the case of direct CCF) or transvenous (most commonly in indirect CCF). Occasionally, more direct approaches, such as direct transorbital puncture of the cavernous sinus or cannulation of the draining superior orbital vein are used when conventional approaches are not possible. Spontaneous resolution of indirect fistulae has been reported but is uncommon. Staged manual compression of the ipsilateral carotid has been reported to assist with spontaneous closure in selected cases.

Direct CCF may be treated by occlusion of the affected cavernous sinus (coils, balloon, liquid agents), or by reconstruction of the damaged internal carotid artery (stent, coils or liquid agents).

Indirect CCF may be treated by occlusion of the affected cavernous sinus with coils, liquid agents or a combination of both.

Treatment for brain AVMs can be symptomatic, and patients should be followed by a neurologist for any seizures, headaches, or focal neurologic deficits. AVM-specific treatment may also involve endovascular embolization, neurosurgery or radiosurgery.

Embolization, that is, cutting off the blood supply to the AVM with coils, particles, acrylates, or polymers introduced by a radiographically guided catheter, may be used in addition to neurosurgery or radiosurgery, but is rarely successful in isolation except in smaller AVMs. Gamma knife may also be used.

The radiocephalic arteriovenous fistula (RC-AVF) is a shortcut between cephalic vein and radial artery at the wrist. It is the recommended first choice for hemodialysis access. Possible underlying causes for failure are stenosis and thrombosis especially in diabetics and those with low blood flow such as due to narrow vessels, arteriosclerosis and advanced age. Reported patency of fistulae after 1 year is about 62.5%.

The procedure was invented by doctors James Cimino and M. J. Brescia in 1966. Before the Cimino fistula was invented, access was through a Scribner shunt, which consisted of a Teflon tube with a needle at each end. Between treatments, the needles were left in place and the tube allowed blood flow to reduce clotting. But Scribner shunts lasted only a few days to weeks. Frustrated by this limitation, James E. Cimino recalled his days as a phlebotomist (blood drawer) at New York City's Bellevue Hospital in the 1950s when Korean War veterans showed up with fistulas caused by trauma. Cimino recognized that these fistulas did not cause the patients harm and were easy places to get repeated blood samples. He convinced surgeon Kenneth Appell to create some in patients with chronic kidney failure and the result was a complete success. Scribner shunts were quickly replaced with Cimino fistulas, and they remain the most effective, longest-lasting method for long-term access to patients' blood for hemodialysis today.

One approach used for treatment is embolization. A six-vessel angiogram is employed to determine the vascular supply to the fistula. Detachable coils, liquid embolic agents like NBCA, and onyx, or combinations of both are injected into the blood vessel to occlude the DAVF. Preoperative embolization can also be used to supplement surgery.

Despite many years of research, the central question of whether to treat AVMs has not been answered. All treatments, whether involving surgery, radiation, or drugs, have risks and side-effects. Therefore, it might be better in some cases to avoid treatment altogether and simply accept a small risk of coming to harm from the AVM itself. This question is currently being addressed in clinical trials.

Preexisting diabetes mellitus of a pregnant mother is a risk factor that has been described for the fetus having TGV.

Carotid cavernous fistulae may form following closed or penetrating head trauma, surgical damage, rupture of an intracavernous aneurysm, or in association with connective tissue disorders, vascular diseases and dural fistulas.

No randomized, controlled clinical trial has established a survival benefit for treating patients (either with open surgery or radiosurgery) with AVMs that have not yet bled.

Passage of a clot (thrombus) from a systemic vein to a systemic artery. When clots in systemic veins break off (embolize), they travel first to the right side of the heart and, normally, then to the lungs where they lodge, causing pulmonary embolism. On the other hand, when there is a hole at the septum, either upper chambers of the heart (an atrial septal defect) or lower chambers of the heart (ventricular septal defects), a clot can cross from the right to the left side of the heart, then pass into the systemic arteries as a paradoxical embolism. Once in the arterial circulation, a clot can travel to the brain, block a vessel there, and cause a stroke (cerebrovascular accident).

Just like berry aneurysm, an intracerebral arteriovenous fistula can rupture causing subarachnoid hemorrhage.

Many pathways are involved in the abnormal proliferation and contraction of the smooth muscle cells of the pulmonary arteries in patients with pulmonary arterial hypertension. Three of these pathways are important since they have been targeted with drugs — endothelin receptor antagonists, phosphodiesterase type 5 (PDE-5) inhibitors, and prostacyclin derivatives.

The dual (ET and ET) endothelin receptor antagonist bosentan was approved in 2001. Sitaxentan (Thelin) was approved for use in Canada, Australia, and the European Union, but not in the United States. In 2010, Pfizer withdrew Thelin worldwide because of fatal liver complications. A similar drug, ambrisentan is marketed as Letairis in the U.S. by Gilead Sciences.

When an arteriovenous fistula is formed involving a major artery like the abdominal aorta, it can lead to a large decrease in peripheral resistance. This lowered peripheral resistance causes the heart to increase cardiac output to maintain proper blood flow to all tissues. 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.

Normal blood flow in the brachial artery is 85 to 110 milliliters per minute (mL/min). After the creation of a fistula, the blood flow increases to 400–500 mL/min immediately, and 700–1,000 mL/min within 1 month. A bracheocephalic fistula above the elbow has a greater flow rate than a radiocephalic fistula at the wrist. Both the artery and the vein dilate and elongate in response to the greater blood flow and shear stress, but the vein dilates more and becomes "arterialized". In one study, the cephalic vein increased from 2.3 mm to 6.3 mm diameter after 2 months. When the vein is large enough to allow cannulation, the fistula is defined as "mature".

An arteriovenous fistula can increase preload. AV shunts also decrease the afterload of the heart. This is because the blood bypasses the arterioles which results in a decrease in the total peripheral resistance (TPR). AV shunts increase both the rate and volume of blood returning to the heart.

The epidemiology of pulmonary heart disease (cor pulmonale) accounts for 7% of all heart disease in the U.S. According to Weitzenblum, et al., the mortality that is related to cor pulmonale is not easy to ascertain, as it is a complication of COPD.

Treatment depends on the location and size of the AVM and whether there is bleeding or not.

The treatment in the case of sudden bleeding is focused on restoration of vital function. Anticonvulsant medications such as phenytoin are often used to control seizure; medications or procedures may be employed to relieve intracranial pressure. Eventually, curative treatment may be required to prevent recurrent hemorrhage. However, any type of intervention may also carry a risk of creating a neurological deficit.

Preventive treatment of as yet unruptured brain AVMs has been controversial, as several studies suggested favorable long-term outcome for unruptured AVM patients not undergoing intervention. The NIH-funded longitudinal ARUBA study ("A Randomized trial of Unruptured Brain AVMs) compares the risk of stroke and death in patients with preventive AVM eradication versus those followed without intervention. Interim results suggest that fewer strokes occur as long as patients with unruptured AVM do not undergo intervention. Because of the higher than expected event rate in the interventional arm of the ARUBA study, NIH/NINDS stopped patient enrollment in April 2013, while continuing to follow all participants to determine whether the difference in stroke and death in the two arms changes over time.

Surgical elimination of the blood vessels involved is the preferred curative treatment for many types of AVM. Surgery is performed by a neurosurgeon who temporarily removes part of the skull (craniotomy), separates the AVM from surrounding brain tissue, and resects the abnormal vessels. While surgery can result in an immediate, complete removal of the AVM, risks exist depending on the size and the location of the malformation. The AVM must be resected en bloc, for partial resection will likely cause severe hemorrhage. The preferred treatment of Spetzler-Martin grade 1 and 2 AVMs in young, healthy patients is surgical resection due to the relatively small risk of neurological damage compared to the high lifetime risk of hemorrhage. Grade 3 AVMs may or may not be amenable to surgery. Grade 4 and 5 AVMs are not usually surgically treated.

Radiosurgery has been widely used on small AVMs with considerable success. The Gamma Knife is an apparatus used to precisely apply a controlled radiation dosage to the volume of the brain occupied by the AVM. While this treatment does not require an incision and craniotomy (with their own inherent risks), three or more years may pass before the complete effects are known, during which time patients are at risk of bleeding. Complete obliteration of the AVM may or may not occur after several years, and repeat treatment may be needed. Radiosurgery is itself not without risk. In one large study, nine percent of patients had transient neurological symptoms, including headache, after radiosurgery for AVM. However, most symptoms resolved, and the long-term rate of neurological symptoms was 3.8%.

Embolization is performed by interventional neuroradiologists and the occlusion of blood vessels most commonly is obtained with Ethylene-vinyl alcohol copolymer (Onyx) or N-butyl cyanoacrylate (NBCA). These substances are introduced by a radiographically guided catheter, and block vessels responsible for blood flow into the AVM. Embolization is frequently used as an adjunct to either surgery or radiation treatment. Embolization reduces the size of the AVM and during surgery it reduces the risk of bleeding. However, embolization alone may completely obliterate some AVMs. In high flow intranidal fistulas balloons can also be used to reduce the flow so that embolization can be done safely.

A paradoxical embolism, also called a crossed embolism, refers to an embolus which is carried from the venous side of circulation to the arterial side, or vice versa. It is a kind of stroke or other form of arterial thrombosis caused by embolism of a thrombus (blood clot), air, tumor, fat, or amniotic fluid of venous origin, which travels to the arterial side through a lateral opening in the heart, such as a patent foramen ovale, or arteriovenous shunts in the lungs.

The opening is typically an atrial septal defect, but can also be a ventricular septal defect.

Paradoxical embolisms represent two percent of arterial emboli.

According to NIH clinical trials.gov, research on the port-wine stain and its relation to polymorphisms of RASA1 has commenced in November 2010 and expected to end in November 2019. The purpose of the study is to assess how the port-wine stains can lead to complex syndromes such as PWS. Currently there is little knowledge about the epidemiology of the stains and how they progress with the disease. The research is ongoing and the results are yet to be published.

In an another review published in July 2017 (discussed in treatments and prognosis), Banzic et. al. discussed clinical findings that embolization works really well in patients with PWS. Also, embolization along with surgical resection that targets arteriovenous malformations reliably leads to significant clinical improvements.

The natural history of this disorder is not well known. The long term outlook for patients with treated moyamoya seems to be good. While symptoms may seem to improve almost immediately after the in-direct EDAS, EMS, and multiple burr holes surgeries, it will take probably 6–12 months before new vessels can develop to give a sufficient blood supply. With the direct STA-MCA surgery, increased blood supply is immediate.

Once major stroke or bleeding take place, even with treatment, the patient may be left with permanent loss of function so it is very important to treat this condition promptly.

Dr. Michael Scott, MD discusses the success rate for Moyamoya surgery in

Sclerotherapy is a treatment for specific veins and vascular malformations in the affected area. It involves the injection of a chemical into the abnormal veins to cause thickening and obstruction of the targeted vessels. Such treatment may allow normal blood flow to resume. It is a non-surgical medical procedure and is not nearly as invasive as debulking. Ultrasound guided foam sclerotherapy is the state of the art new treatment which could potentially close many large vascular malformations.

Compression therapies are finding more use as of the last ten years. The greatest issue with KTS syndrome is that the blood flow and/or lymph flow may be impeded, and will pool in the affected area. This can cause pain, swelling, inflammations, and in some cases, even ulceration and infection. Among older children and adults, compression garments can be used to alleviate almost all of these, and when combined with elevation of the affected area and proper management, can result in a comfortable lifestyle for the patient without any surgery. Compression garments are also used lately after a debulking procedure to maintain the results of the procedure. For early treatment of infants and toddlers with KTS, custom compression garments are impractical because of the rate of growth. When children may benefit from compression therapies, wraps and lymphatic massage may be used. While compression garments or therapy are not appropriate for everyone, they are relatively cheap (compared to surgery), and have few side-effects. Possible side-effects include a slight risk that the fluids may simply be displaced to an undesirable location (e.g., the groin), or that the compression therapy itself further impedes circulation to the affected extremities.

The treatment for cor pulmonale can include the following: antibiotics, expectorants, oxygen therapy, diuretics, digitalis, vasodilators, and anticoagulants. Some studies have indicated that Shenmai injection with conventional treatment is safe and effective for cor pulmonale (chronic).

Treatment requires diuretics (to decrease strain on the heart). Oxygen is often required to resolve the shortness of breath. Additionally, oxygen to the lungs also helps relax the blood vessels and eases right heart failure. When wheezing is present, the majority of individuals require a bronchodilator. A variety of drugs have been developed to relax the blood vessels in the lung, calcium channel blockers are used but only work in few cases and according to NICE are not recommended for use at all.

Anticoagulants are used when venous thromboembolism is present. Venesection is used in severe secondary polycythaemia (because of hypoxia), which improves symptoms though survival rate has not been proven to increase.Finally, transplantation of single/double lung in extreme cases of cor pulmonale is also an option.