Vascular ring is an abnormal formation of the aorta, the large artery that carries blood from the heart to the rest of the body. It is a congenital problem, which means it is present at birth.
See also: Double aortic arch
Alternative NamesRight aortic arch with aberrant subclavian and left ligamentum
Causes, incidence, and risk factorsVascular ring is rare. It accounts for less than 1% of all congenital heart problems. The condition occurs as often in males as females. Some infants with vascular ring also have another congenital heart problem.
Vascular ring occurs very early in the baby's development in the womb. Normally, the aorta develops from one of several curved pieces of tissue (arches). The body breaks down some of the remaining arches, while others form into arteries. Some arteries that should break down do not; this forms vascular rings.
With vascular ring, some of the arches and vessels that should have changed into arteries or disappeared are still present when the baby is born. These arches form a ring of blood vessels, which encircles and presses down on the windpipe (trachea) and esophagus.
Several different types of vascular ring exist. In some types, the vascular ring only partially encircles the trachea and esophagus, but it still can cause symptoms.
SymptomsSome children with a vascular ring never develop symptoms. However, in most cases, symptoms are seen during infancy. Pressure on the windpipe (trachea) and esophagus can lead to breathing and digestive problems. The more the ring presses down, the more severe the symptoms will be.
Breathing problems may include:
Eating may make breathing symptoms worse.
Digestive symptoms are rare, but may include:
The doctor will listen to the baby's breathing to rule out other breathing disorders such as Asthma. Listening to the child's heart through a stethoscope can help identify murmurs and other heart problems.
The following tests can help diagnose vascular ring:
Surgery is usually performed as soon as possible on children with symptoms. The goal of surgery is to split the vascular ring and relieve pressure on the surrounding structures. The surgery is not very invasive. The procedure is usually done through a small surgical cut in the left side of the chest between the ribs.
Changing the child's diet may help relieve the digestive symptoms of vascular ring. The doctor will prescribe medications (such as antibiotics) to treat any respiratory tract infections, if they occur.
Children who don't have symptoms may not need treatment, but should be carefully watched to make sure the condition doesn't become worse.
Expectations (prognosis)How well the infant does depends on how much pressure the vascular ring is putting on the esophagus and trachea and how quickly the infant is diagnosed and treated.
Surgery works well in most cases and often relieves symptoms right away. Severe breathing problems may take months to go away. Some children may continue to have loud breathing, especially when they are very active or have respiratory infections.
ComplicationsDelaying surgery can lead to serious complications such as damage to the trachea and even death. Calling your health care providerCall your health care provider if your baby has symptoms of vascular ring. Getting diagnosed and treated quickly can prevent serious complications. PreventionThere is no known way to prevent this condition. ReferencesOther congenital heart and vascular malformations. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 18th ed. Philadelphia, Pa: Saunders Elsevier; 2007chap 432.
Vascular ring is an abnormal formation of the aorta, the large artery that carries blood from the heart to the rest of the body. It is a congenital problem, which means it is present at birth.
See also: Double aortic arch
Alternative NamesRight aortic arch with aberrant subclavian and left ligamentum
Causes, incidence, and risk factorsVascular ring is rare. It accounts for less than 1% of all congenital heart problems. The condition occurs as often in males as females. Some infants with vascular ring also have another congenital heart problem.
Vascular ring occurs very early in the baby's development in the womb. Normally, the aorta develops from one of several curved pieces of tissue (arches). The body breaks down some of the remaining arches, while others form into arteries. Some arteries that should break down do not; this forms vascular rings.
With vascular ring, some of the arches and vessels that should have changed into arteries or disappeared are still present when the baby is born. These arches form a ring of blood vessels, which encircles and presses down on the windpipe (trachea) and esophagus.
Several different types of vascular ring exist. In some types, the vascular ring only partially encircles the trachea and esophagus, but it still can cause symptoms.
SymptomsSome children with a vascular ring never develop symptoms. However, in most cases, symptoms are seen during infancy. Pressure on the windpipe (trachea) and esophagus can lead to breathing and digestive problems. The more the ring presses down, the more severe the symptoms will be.
Breathing problems may include:
Eating may make breathing symptoms worse.
Digestive symptoms are rare, but may include:
The doctor will listen to the baby's breathing to rule out other breathing disorders such as asthma. Listening to the child's heart through a stethoscope can help identify murmurs and other heart problems.
The following tests can help diagnose vascular ring:
Surgery is usually performed as soon as possible on children with symptoms. The goal of surgery is to split the vascular ring and relieve pressure on the surrounding structures. The surgery is not very invasive. The procedure is usually done through a small surgical cut in the left side of the chest between the ribs.
Changing the child's diet may help relieve the digestive symptoms of vascular ring. The doctor will prescribe medications (such as antibiotics) to treat any respiratory tract infections, if they occur.
Children who don't have symptoms may not need treatment, but should be carefully watched to make sure the condition doesn't become worse.
Expectations (prognosis)How well the infant does depends on how much pressure the vascular ring is putting on the esophagus and trachea and how quickly the infant is diagnosed and treated.
Surgery works well in most cases and often relieves symptoms right away. Severe breathing problems may take months to go away. Some children may continue to have loud breathing, especially when they are very active or have respiratory infections.
ComplicationsDelaying surgery can lead to serious complications such as damage to the trachea and even death. Calling your health care providerCall your health care provider if your baby has symptoms of vascular ring. Getting diagnosed and treated quickly can prevent serious complications. PreventionThere is no known way to prevent this condition. ReferencesBernstein D. Other congenital heart and vascular malformations. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, Pa: Saunders Elsevier; 2011;chap 426.
Reviewed ByReview Date: 02/07/2012
Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine; and Michael A. Chen, MD, PhD, Assistant Professor of Medicine, Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, Washington. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
There are two types of plants, monocots and dicots. Monocots have vascular bundles that are randomly distributed and dicots have their vascular bundles in an organized ring.
they are in a ring shape.
in a ring shape
stelar region or outside vascular ring
They form a ring where phloem forms an outer ring around the xylem.
The structure of a stem has different intereal structures. They have vascular tissues. Stems have a bundled arrangement of circular vascular tissues. The xylem and phloem are in a circle of vascular tissues that form a ring around cortex.
The pith
a ring of vascular tissues
The vascular bundles would be arranged in a ring around the pith. The flower would be a dicot, because the four characteristics of dicots are: ~flower parts in fours or fives ~two cotyledons (embryonic leaves) ~veins in leaves branch out ~vascular bundles are arranged in a ring
annual growth ring
The vascular bundles are arranged in a loose circle inside the endodermis of a monocot root. In a monocot root, there are eight bundles of xylem and eight bundles of phloem. The phloem forms a cylinder outside of the cylinder of xylem.For more information (and diagrams of a monocot root) see the page links, further down this page, listed under Related Questions and Related Links.
The ring of cells which surrounds the vascular tissue.