This is based on MRI scan, magnetic resonance angiography and CT scan. A cerebral digital subtraction angiography (DSA) enhances visualization of the fistula.

- CT scans classically show an enlarged superior ophthalmic vein, cavernous sinus enlargement ipsilateral (same side) as the abnormality and possibly diffuse enlargement of all the extraocular muscles resulting from venous engorgement.

- Selective arteriography is used to evaluate arteriovenous fistulas.

- High resolution digital subtraction angiography may help in classifying CCF into dural and direct type and thus formulate a strategy to treat it either by a balloon or coil or both with or without preservation of parent ipsilateral carotid artery.

Treatment depends on the anatomy of the malformation as determined by angiography or Magnetic Resonance Imaging (MRI).

Cerebral angiography is the diagnostic standard. MRIs are usually normal.

Testing for a malformed vein of Galen is indicated when a patient has heart failure which has no obvious cause. Diagnosis is generally achieved by signs such as cranial bruits and symptoms such as expanded facial veins. The vein of Galen can be visualized using ultrasound or Doppler. A malformed Great Cerebral Vein will be noticeably enlarged. Ultrasound is a particularly useful tool for vein of Galen malformations because so many cases occur in infancy and ultrasound can make diagnoses prenatally. Many cases are diagnosed only during autopsy as congestive heart failure occurs very early.

The Cognard et al. Classification correlates venous drainage patterns with increasingly aggressive neurological clinical course.

AVMs are diagnosed primarily by the following methods:

- Computerized tomography (CT) scan is a noninvasive X-ray to view the anatomical structures within the brain to detect blood in or around the brain. A newer technology called CT angiography involves the injection of contrast into the blood stream to view the arteries of the brain. This type of test provides the best pictures of blood vessels through angiography and soft tissues through CT.

- Magnetic resonance imaging (MRI) scan is a noninvasive test, which uses a magnetic field and radio-frequency waves to give a detailed view of the soft tissues of the brain.

- Magnetic resonance angiography (MRA) – scans created using magnetic resonance imaging to specifically image the blood vessels and structures of the brain. A magnetic resonance angiogram can be an invasive procedure, involving the introduction of contrast dyes (e.g., gadolinium MR contrast agents) into the vasculature of a patient using a catheter inserted into an artery and passed through the blood vessels to the brain. Once the catheter is in place, the contrast dye is injected into the bloodstream and the MR images are taken. Additionally or alternatively, flow-dependent or other contrast-free magnetic resonance imaging techniques can be used to determine the location and other properties of the vasculature.

AVMs can occur in various parts of the body:

- brain (cerebral AV malformation)

- spleen

- lung

- kidney

- spinal cord

- liver

- intercostal space

- iris

- spermatic cord

- extremities – arm, shoulder, etc.

AVMs may occur in isolation or as a part of another disease (for example, Von Hippel-Lindau disease or hereditary hemorrhagic telangiectasia).

AVMs have been shown to be associated with aortic stenosis.

Bleeding from an AVM can be relatively mild or devastating. It can cause severe and less often fatal strokes. If a cerebral AVM is detected before a stroke occurs, usually the arteries feeding blood into the nidus can be closed off to avert the danger. However, interventional therapy may also be relatively risky.

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.

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.

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

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.

Treatment for fistula varies depending on the cause and extent of the fistula, but often involves surgical intervention combined with antibiotic therapy.

Typically the first step in treating a fistula is an examination by a doctor to determine the extent and "path" that the fistula takes through the tissue.

In some cases the fistula is temporarily covered, for example a fistula caused by cleft palate is often treated with a palatal obturator to delay the need for surgery to a more appropriate age.

Surgery is often required to assure adequate drainage of the fistula (so that pus may escape without forming an abscess). Various surgical procedures are commonly used, most commonly fistulotomy, placement of a seton (a cord that is passed through the path of the fistula to keep it open for draining), or an endorectal flap procedure (where healthy tissue is pulled over the internal side of the fistula to keep feces or other material from reinfecting the channel). Treatment involves filling the fistula with fibrin glue; also plugging it with plugs made of porcine small intestine submucosa have also been explored in recent years, with variable success. Surgery for anorectal fistulae is not without side effects, including recurrence, reinfection, and incontinence. High rate of recurrence and more chances of complications like incontinence are always there in fistula surgeries (Anal Fistula).

It is important to note that surgical treatment of a fistula without diagnosis or management of the underlying condition, if any, is not recommended. For example, surgical treatment of fistulae in Crohn's disease can be effective, but if the Crohn's disease itself is not treated, the rate of recurrence of fistula is very high (well above 50%).

Various types of fistulas include:

Although most fistulas are in forms of a tube, some can also have multiple branches.

An arteriovenous fistula is an abnormal connection or passageway between an artery and a vein. It may be congenital, surgically created for hemodialysis treatments, or acquired due to pathologic process, such as trauma or erosion of an arterial aneurysm.

"Diagnosis" is by examination, either in an outpatient setting or under anaesthesia (referred to as — Examination Under Anaesthesia). The fistula may be explored by using a fistula probe (a narrow instrument). In this way, it may be possible to find both openings. The examination can be an anoscopy. Diagnosis may be aided by performing a fistulogram, proctoscopy and/or sigmoidoscopy.

Possible findings:

- The opening of the fistula onto the skin may be observed

- The area may be painful on examination

- There may be redness

- An area of induration may be felt — thickening due to chronic infection

- A discharge may be seen

CLASSIFICATIONS of ANAL FISTULA

- Park's Classification: This was done in 1976 by Parks et al from UK. This was done in the era when MRI or Endoanal Ultrasound was not there. It classified the fistula in four grades

- St James University Hospital Classification: This was done by Morris et al in the year 2000. This classification was improvement over Parks classification as it was based on MRI studies. It classified the fistula in five grades.

- Garg Classification: This was done by Pankaj Garg in 2017. This classification is improvement over both Parks and St James University Hospital Classification. This was based on MRI studies and operative findings in 440 patients. It classified the fistula in five grades. The grades of this classification correlate quite well with the severity of the disease. Grade I & II are simpler fistulas and can be managed by Fistulotomy whereas grade III-V are complex fistulas in which fistulotomy should be not be done. They should be managed by Fistula experts. Unlike Park's and St James University Hospital Classification, this correlation is quite accurate with Garg's classification. Therefore this new classification is useful to both surgeons and radiologists

To prevent an TIF, intubation time should be limited to less than 2 weeks and proper techniques should be used when performing tracheotomies. The occurrence of an TIF can be reduced by using more flexible and blunt tracheostomy tubes and insuring that the tubes are properly aligned in the patients. Placing the tracheostomy between the second and third tracheal rings can minimize the risk of an TIF. Repetitive head movements, especially, hyperextension of the neck should be avoided as since this movement results in contact between the innominate artery and the underside of the tube.

Other conditions in which infected perianal "holes" or openings may appear include Pilonidal cysts/sinuses.

TIF is a rare condition with a .7% frequency, and an mortality rate approaching 100% without surgical intervention. Immediate diagnosis and intervention of an TIF is critical for the surgical intervention success. 25-30% of TIF patients who reach the operating room survive. Recently, the incidence of TIF may have declined due to advances in tracheostomy tube technology and the introduction of the bedside percutaneous dilatational tracheostomy (PDT).

There is disagreement as to how cases of KTS should be classified if there is an arteriovenous fistula present. Although several authorities have suggested that the term Parkes-Weber syndrome is applied in those cases, ICD-10 currently uses the term "Klippel–Trénaunay–Weber syndrome".

Clinical features can be found in the subhyoid portion of the tract and 75% present as midline swellings. The remainder can be found as far lateral as the lateral tip of the hyoid bone.

Typically, the cyst will move upwards on protrusion of the tongue, given its attachment to the embryonic duct, as well as on swallowing, due to attachment of the tract to the foramen caecum.

History and examination by a physician with characteristic signs and symptoms are sufficient in many cases in ruling out systemic causes of venous hypertension such as hypervolemia and heart failure. An ultrasound (usually a lower limbs venous ultrasonography) can detect venous obstruction or valvular incompetence as the cause, and is used for planning venous ablation procedures, but it is not necessary in suspected venous insufficiency where surgical intervention is not indicated.

Diagnosis of a thyroglossal duct cyst requires a medical professional, and is usually done by a physical examination. It is important to identify whether or not the thyroglossal cyst contains any thyroid tissue, as it can define the degree of cyst that is being dealt with.

Diagnostic procedures for a thyroglossal cyst include:

Making a correct diagnosis for a genetic and rare disease is often times very challenging. So the doctors and other healthcare professions rely on the person’s medical history, the severity of the symptoms, physical examination and lab tests to make and confirm a diagnosis.

There is a possibility of interpreting the symptoms of PWS with other conditions such as AVMs and or AVFs. This is because AVMs and AVFs also involve the characteristic overgrowth in soft tissue, bone and brain. Also PWS can be misdiagnosed with Klippel–Trenaunay syndrome (KTS). However, KTS consists of the following: triad capillary malformation, venous malformation, and lymphatic malformation.

Usually a specific set of symptoms such as capillary and arteriovenous malformations occur together and this is used to distinguish PWS from similar conditions. Arteriovenous malformations (AVMs) and arteriovenous fistulas (AVFs) are caused by RASA1 mutations as well. Therefore, if all the other tests (discussed below) fail to determine PWS, which is highly unlikely, genetic testing such as sequence analysis and gene-targeted deletion/duplication analysis can be performed to identify possible RASA1 gene mutations.

But PWS can be distinguished from other conditions because of its defining port-wine stains that are large, flat and pink. The port-wine stains and physical examination are enough to diagnose PWS. But additional testing is necessary to determine the extent of the PWS syndrome. The following tests may be ordered by physicians to help determine the appropriate next steps: MRI, ultrasound, CT/CAT scan, angiogram, and echocardiogram.

MRI: This is a high-resolution scan that is used to identify the extent of the hypertrophy or overgrowth of the tissues. This can also be used to identify other complications that may arise a result of hypertrophy.

Ultrasound: this can be necessary to examine the vascular system and determine how much blood is actually flowing through the AVMs.

CT/CAT scan: this scan is especially useful for examining the areas affected by PWS and is helpful for evaluating the bones in the overgrown limb.

Angiogram: an angiogram can also be ordered to get a detailed look at the blood vessels in the affected or overgrown limb. In this test an interventional radiologist injects a dye into the blood vessels that will help see how the blood vessels are malformed.

Echocardiogram: depending on the intensity of the PWS syndrome, an echo could also be ordered to check the condition of the heart.

And PWS often requires a multidisciplinary care. Depending on the symptoms, patients are dependent on: dermatologists, plastic surgeons, general surgeons, interventional radiologists, orthopedists, hematologists, neurosurgeons, vascular surgeons and cardiologists. Since the arteriovenous and capillary malformations cannot be completely reconstructed and depending on the extent and severity of the malformations, these patients may be in the care of physicians for their entire lives.

Vascular malformation is a blood vessel abnormality. There are many types, but the most common is arteriovenous malformation.

It may cause aesthetic problems as it has a growth cycle and can continue to grow throughout life. This is also known as Vascular giantism or lymphangiomas.

Smith (2015) conducted a study that looked into specific biological markers that correlate to Moyamoya disease. Some of the categories of these biomarkers include phenotypes - conditions commonly related to Moyamoya, radiographical markers for the diagnosis of Moyamoya, and proteins as well as cellular changes that occur in cases of Moyamoya.

Similar to Moyamoya Disease, there are conditions that are closely associated with Moyamoya Syndrome. Some of the more common medical conditions that are closely associated with Moyamoya Syndrome include trisomy 21 (Down's Syndrome), sickle cell disease, and neurofibromatosis type 1. There is also evidence that identifies hyperthyroidism and congenital dwarfing syndromes as two of the more loosely associated syndromes that correlate with the possibility of being diagnosed with Moyamoya Disease later in life.

There is also research that has shown that certain radiographic biomarkers that lead to the diagnosis of Moyamoya Disease have been identified. The specific radiographic markers are now considered an acceptable key component to Moyamoya Disease and have been added to the INternational Classification of Diseases (ICD). These biomarkers of Moyamoya are "stenosis of the distal ICA's up to and including the bifurcation, along with segments of the proximal ACA and MCA...dilated basal collateral vessels must be present" Some other common findings that have not been added to the classification index of those with Moyamoya Disease which are found using radiography involve very distinct changes in the vessels of the brain. These changes include newly formed vessels made to compensate for another change noted, ischemia and cerebrovascular reserve, both found on MRI. Functional changes include evidence of ischemia in vessels of the brain (ICA, ACA, MCA, specifically). It is important to also note that the radiographic biomarkers, in order to be classified as Moyamoya Disease, all findings must be bilateral. If this is not the case and the findings are unilateral, it is diagnosed as Moyamoya Syndrome.

There are also several protein biomarkers that have been linked to the Moyamoya Disease diagnosis. Although the sample size of the studies performed are small due to the rarity of the disease, the findings are indicative of a correlation between the disease and several specific protein biomarkers. Other studies have confirmed the correlation of Moyamoya and adhesion molecule 1 (ICAM-1) being increased as compared to normal vascular function counterparts Furthermore, it has been concluded that the localization of inflammatory cells suggests that the inflammation stimulus iteself may be responsible for the proliferation and occlusion in the ICA, ACA, and MCA found in those with Moyamoya Disease.