What is a Vascular Ring?
A vascular ring is a type of congenital (present at birth) defect. This happens when normal vessels are in the wrong place. This may cause pressure on the esophagus or airway.
These vessels known as arteries may carry blood to the body, to the lungs, or both. They are listed in three groups: vascular rings, the innominate compression syndrome, and pulmonary arterial slings
Vascular rings can vary. They can affect the aortic arch resulting in the formation of a ring going around the trachea and esophagus.
The aorta is the largest artery in the body. The aorta delivers oxygen to all parts of the body. When a baby is developing parts of the arch may not form correctly.
The two most common differences of true vascular rings, are persistent double aortic arch and right aortic arch with abnormal connection of the left subclavian artery.
The left-sided ligamentum arteriosum (scar tissue formed as a remainder of the ductus arteriosus within three weeks of birth) completes the vascular ring..
Problems Caused by Vascular Rings
There are many symptoms seen when vascular rings are present. Most vascular rings are not found before birth.
Many patients do not have symptoms or have mild symptoms. Vascular rings diagnosed in patients less than 6 months of age are usually a result of a patient having noisy breathing (stridor). Worsening of breathing difficulties with feeding or during upper respiratory infections may be seen.
Children with double aortic arch defects show up earlier than those with right aortic arch defects. Swallowing problems are uncommon in the first months of life.
Choking or swallowing difficulties are more common in older children as the main symptoms. A vascular ring can be discovered by chance during evaluation of an unrelated problem.
Diagnosis of Vascular Rings
Physical examination may help characterize the "noisy breathing." This may help separate it from other more common problems such as asthma.
With a vascular ring, the noisy breathing may be heard both during inspiration (breathing in) and expiration (breathing out). While in asthma, the noise is at the end of expiration.
Occasionally, physical examination will find a weak pulse in an arm or the legs. Listening to the chest for murmurs is often part of the assessment.
A chest X-ray is often done as a part of the initial evaluation. If the aortic arch is on the right-side, a vascular ring should be suspected. Seeing the aortic arch on the plain chest X-ray, may be hard in some children.
Patients with swallowing difficulties should complete a barium swallow study as part of the first evaluation. This will typically show abnormal compression of the middle part of the esophagus.
A barium study that shows classic features of a vascular ring, along with a chest X-ray showing a right-sided aortic arch is all that is needed to move forward with surgery.
A chest CT or MRI will often be ordered to show the relationship of the vessels, the trachea and the esophagus.
When breathing symptoms are moderate to severe a bronchoscopy may be done.
Treatment of Vascular Rings
Surgery to divide the vascular ring is indicated in all symptomatic cases.
There is a low risk with surgery to divide a vascular ring. Most doctors will choose surgery over watching the patient closely.
The goal of surgery for vascular rings is to make sure blood can flow through the vessels freely. When the ring is open in at least one direction, symptoms will be relieved.
In most cases the surgery is done using an small cut on the left side of the chest. This allows entry between the ribs. In the case of double aortic arch, the left side of the ring (which is usually the smaller side) is divided where it is putting pressure on the esophagus.
With a right aortic arch and abnormal left subclavian artery, the ligamentum arteriosum (a ligament that was a blood vessel during fetal life) is divided between the descending aorta and the pulmonary artery. Hospitalization after surgery is usually a day or two.
Treatment of Vascular Rings: Results
Complete relief of symptoms may show up right away after surgery.
In infants, there may be some degree of tracheomalacia (floppiness of the trachea). This may be seen during active times or during upper respiratory infections.
Improvement of swallowing symptoms in such cases may be seen gradually.
Adult and Adolescent Management
Vascular rings do not often present in adult life. When they do, they are assessed and managed by surgeons. If they have been repaired, the patient usually becomes free of symptoms. They do not need ongoing follow up with a doctor.