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 (, ).

10-15% of intracranial AV malformations are DAVFs. There is a higher preponderance in females (61-66%), and typically patients are in their fourth or fifth generation of life. DAVFs are rarer in children.

The complications that are usually associated with vein of Galen malformations are usually intracranial hemorrhages. Over half the patients with VGAM have a malformation that cannot be corrected. Patients frequently die in the neonatal period or in early infancy.

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.

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%.

Various classifications have been proposed for CCF. They may be divided into low-flow or high-flow, traumatic or spontaneous and direct or indirect. The traumatic CCF typically occurs after a basal skull fracture. The spontaneous dural cavernous fistula which is more common usually results from a degenerative process in older patients with systemic hypertension

and atherosclerosis. Direct fistulas occur when the Internal Carotid artery (ICA) itself fistulizes into the Cavernous sinus whereas indirect is when a branch of the ICA or External Carotid artery (ECA) communicates with the cavernous sinus.

A popular classification divides CCF into four varieties depending on the type of arterial supply.

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.

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

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.

Surgically created AV fistulas work effectively because they:

- Have high volume flow rates (as blood takes the path of least resistance; it prefers the (low resistance) AV fistula over traversing (high resistance) capillary beds).

- Use native blood vessels, which, when compared to synthetic grafts, are less likely to develop stenoses and fail.

A cirsoid aneurysm is the dilation of a group of blood vessels due to congenital malformations with AV (arterio venous) shunting. Cirsoid means resembling a varix.

Sometimes, a minor traumatic episode, such as a fall or bump on the head, can lead to the formation of a cirsoid aneurysm. Often these are trivial traumatic episodes

Cirsoid aneurysm, in general, is a hemangioma of an artery. It most commonly occurs over the head, usually the superficial temporal artery and also its branches. It can also occur in places where medium vessels lie over bones without much intervening tissues between them and the skin.

The superficial temporal artery is the most commonly involved artery.

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).

In people with renal failure, requiring dialysis, a cimino fistula is often deliberately created in the arm by means of a short day surgery in order to permit easier withdrawal of blood for hemodialysis.

As a radical treatment for portal hypertension, surgical creation of a portacaval fistula produces an anastomosis between the hepatic portal vein and the inferior vena cava across the omental foramen (of Winslow). This spares the portal venous system from high pressure which can cause esophageal varices, caput medusae, and hemorrhoids.

Various types of fistulas include:

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

Neonates with TEF or esophageal atresia are unable to feed properly. Once diagnosed, prompt surgery is required to allow the food intake. Some children do experience problems following TEF surgery; they can develop dysphagia and thoracic problems. Children with TEF can also be born with other abnormalities, most commonly those described in VACTERL association - a group of anomalies which often occur together, including heart, kidney and limb deformities. 6% of babies with TEF also have a laryngeal cleft.

Imperforate anus has an estimated incidence of 1 in 5000 births. It affects boys and girls with similar frequency. However, imperforate anus will present as the low version 90% of the time in females and 50% of the time in males.

Imperforate anus is an occasional complication of sacrococcygeal teratoma.

The innominate artery usually crosses the trachea at the ninth cartilage ring, however this can vary from the sixth to the thirteenth cartilage ring in patients. A TIF runs between the trachea and the innominate artery. Through this connection blood from within the artery may pass into the trachea or alternatively air from within the trachea may cross into the artery.

TIF is a late complication of a tracheotomy and is associated with prolonged endotracheal intubation, as a result of cuff over inflation or a poorly positioned tracheostomy tube. Over inflation of the cuff causes the tracheostomy tube to erode into the posterior aspect of the innominate artery leading to the formation of a fistula. The pathogenesis of an TIF by the aforementioned method is pressure necrosis by tracheostomy tube on the tracheal wall. An TIF can also occur due to innominate artery injury as a result of an bronchoscopy.

Patients whose tracheotomies are placed beneath the third tracheal ring cartilage and patients with innominate arteries crossing higher on the trachea have an increased risk of developing an TIF. Other factors contributing to the development of TIF include steroids, which weaken the endotracheal mucosa, episodes of hypotension in which the pressure in the tracheostomy tube exceeds that of the endotracheal mucosa, and radiation therapy.

An endotracheal tumor can mimic a TIF and present with massive bleeding during a rigid bronchoscopy.

Patients with abnormal cardiac and kidney function may be more at risk for hemolytic uremic syndrome

The incidence of VACTERL association is estimated to be approximately 1 in 10,000 to 1 in 40,000 live-born infants. It is seen more frequently in infants born to diabetic mothers. While most cases are sporadic, there are clearly families who present with multiple involved members.

Twenty to 27% of individuals with a laryngeal cleft also have a tracheoesophageal fistula and approximately 6% of individuals with a fistula also have a cleft. Other congenital anomalies commonly associated with laryngeal cleft are gastro-oesophageal reflux, tracheobronchomalacia, congenital heart defect, dextrocardia and situs inversus. Laryngeal cleft can also be a component of other genetic syndromes, including Pallister-Hall syndrome and G syndrome (Opitz-Friaz syndrome).

One reason that poverty produces such high rates of fistula cases is the malnutrition that exists in such areas. Lack of money and access to proper nutrition, as well as vulnerability to diseases that exist in impoverished areas because of limited basic health care and disease prevention methods, cause inhabitants of these regions to experience stunted growth. Sub-Saharan Africa is one such environment where the shortest women have on average lighter babies and more difficulties during birth when compared with full-grown women. This stunted growth causes expectant mothers to have skeletons unequipped for proper birth, such as an underdeveloped pelvis. This weak and underdeveloped bone structure increases the chances that the baby will get stuck in the pelvis during birth, cutting off circulation and leading to tissue necrosis. Because of the correlation between malnutrition, stunted growth, and birthing difficulties, maternal height can at times be used as a measure for expected labor difficulties.

High levels of poverty also lead to low levels of education among impoverished women concerning maternal health. This lack of information in combination with obstacles preventing rural women to easily travel to and from hospitals lead many to arrive at the birthing process without prenatal care. This can cause a development of unplanned complications that may arise during home births, in which traditional techniques are used. These techniques often fail in the event of unplanned emergencies, leading women to go to hospital for care too late, desperately ill, and therefore vulnerable to the risks of anesthesia and surgery that must be used on them. In a study of women who had prenatal care and those who had unbooked emergency births, “the death rate in the booked-healthy group was as good as that in many developed countries, [but] the death rate in the unbooked emergencies was the same as the death rate in England in the 16th and 17th centuries.” In this study, 62 unbooked emergency women were diagnosed with obstetric fistulae out of 7,707 studied, in comparison to three diagnosed booked mothers out of 15,020 studied. In addition, studies find that education is associated with lower desired family size, greater use of contraceptives, and increased use of professional medical services. Educated families are also more likely to be able to afford health care, especially maternal healthcare.

Surgical repair can sometimes result in complications, including:

- Stricture, due to gastric acid erosion of the shortened esophagus

- Leak of contents at the point of anastomosis

- Recurrence of fistula

- Gastro-esophageal reflux disease

- Dysphagia

- Asthma-like symptoms, such as persistent coughing/wheezing

- Recurrent chest infections

- Tracheomalacia

Arterial tortuosity syndrome is a rare congenital connective tissue condition disorder characterized by elongation and generalized tortuosity of the major arteries including the aorta. It is associated with hyperextensible skin and hypermobility of joints, however symptoms vary depending on the person. Because ATS is so rare, not much is known about the disease.

Treatment of a laryngeal cleft depends on the length and resulting severity of symptoms. A shallow cleft (Type I) may not require surgical intervention. Symptoms may be able to be managed by thickening the infant's feeds. If symptomatic, Type I clefts can be sutured closed or injected with filler as a temporary fix to determine if obliterating the cleft is beneficial and whether or not a more formal closure is required at a later date. Slightly longer clefts (Type II and short Type III) can be repaired endoscopically. Short type IV clefts extending to within 5 mm below the innominate artery can be repaired through the neck by splitting the trachea vertically in the midline and suturing the back layers of the esophagus and trachea closed. A long, tapered piece of rib graft can be placed between the esophageal and tracheal layers to make them rigid so the patient will not require a tracheotomy after the surgery and to decrease chances of fistula postoperatively. Long Type IV clefts extending further than 5 mm below the innominate artery cannot be reached with a vertical incision in the trachea, and therefore are best repaired through cricotracheal resection. This involves separating the trachea from the cricoid cartilage, leaving the patient intubated through the trachea, suturing each of the esophagus and the back wall of the trachea closed independently, and then reattaching the trachea to the cricoid cartilage. This prevents the need for pulmonary bypass or extracorporeal membrane oxygenation.