What is VACTERL association / VATER Syndrome?
VACTERL or VATER association is an acronym used to describe a series of characteristics which have been found to occur together.
V stands for vertebrae, which are the bones of the spinal column.
A stands for imperforate anus or anal atresia, or an anus that does not open to the outside of the body.
C is added to the acronym to denote cardiac anomalies.
TE stands for tracheoesophageal fistula, which is a persistent connection between the trachea (the windpipe) and the esophagus (the feeding tube).
R stands for renal or kidney anomalies.
L is often added to stand for limb anomalies (radial agenesis).
Babies who have been diagnosed as having VACTERL association usually have at least three or more of these individual anomalies. There is a wide range of manifestation of VACTERL association so that the exact incidence within the population is not exactly known, but has been estimated to occur in one in 10,000 to 40,000 newborns.
Heart Problems with VACTERL Association
Up to 75 percent of patients with VACTERL association have been reported to have congenital heart disease.
The most common heart defects seen with VACTERL association are ventricular septal defect (VSD), atrial septal defects and tetralogy of Fallot.
Less common defects are truncus arteriosus and transposition of the great arteries. Babies may have a murmur at birth, however absence of a murmur does not rule out congenital heart disease. If a baby is suspected of having VACTERL association, consultation with a pediatric cardiologist is recommended.
Other Defects with VACTERL Association
Vertebral anomalies, or defects of the spinal column, usually consist of small (hypoplastic) vertebrae or hemivertebra where only one half of the bone is formed.
About 70 percent of patients with VACTERL association will have vertebral anomalies. In early life these rarely cause any difficulties, although the presence of these defects on a chest X-ray may alert the physician to other defects associated with VACTERL.
Later in life these spinal column abnormalities may put the child at risk for developing scoliosis, or curvature of the spine.
Anal atresia or imperforate anus is seen in about 55 percent of patients with VACTERL association. These anomalies are usually noted at birth and often require surgery in the first days of life. Sometimes babies will require several surgeries to fully reconstruct the intestine and anal canal.
Esophageal atresia with tracheoesophageal fistula (TE fistula) is seen in about 70 percent of patients with VACTERL association, although it can frequently occur as an isolated defect.
Fifteen percent to 33 percent of patients with TE fistulas will also have congenital heart disease. However these babies usually have uncomplicated heart defects, like a VSD, which may not require any surgery.
Renal or kidney defects are seen in approximately 50 percent of patients with VACTERL association. In addition, up to 35 percent of patients with VACTERL association have a single umbilical artery (there are usually two) which can often be associated with kidney or urologic problems.
These defects can be severe with incomplete formation of one or both kidneys or urologic abnormalities such as obstruction of outflow of urine from the kidneys or severe reflux (backflow) of urine into the kidneys from the bladder.
These problems can cause kidney failure early in life and may require kidney transplant. Many of these problems can be corrected surgically before any damage can occur.
Limb defects occur in up to 70 percent of babies with VACTERL association and include absent or displaced thumbs, extra digits (polydactyly), fusion of digits (syndactyly) and forearm defects.
Babies with limb defects on both sides tend to have kidney or urologic defects on both sides, while babies with limb defects on only one side of the body tend to have kidney problems on that same side.
Many babies with VACTERL are born small and have difficulty gaining weight. However, they tend to have normal development and intelligence.
VACTERL Association Causes
The cause of VACTERL association is not well understood. VACTERL association is a complex condition that may have different causes in different people. No specific genetic or chromosome problem has been identified with VACTERL association. Multiple genetic and environmental factors likely play a part in determining the risk of developing this condition and how severe the condition will be in an individual. Some possible genetic and environmental influences are being studied.
The developmental abnormalities characteristic of VACTERL association develop before birth. The disruption to typical development that causes VACTERL association likely occurs early in development, resulting in birth defects that affect multiple body systems. It is unclear why the features characteristic of VACTERL association group together in affected individuals.
Diagnosis of VACTERL Association
As there is no available laboratory test for diagnosis, VACTERL association is diagnosed based on the presence of clinical features. People diagnosed with VACTERL association typically have at least three of the characteristic features described above. Affected individuals may have additional abnormalities that are not among the characteristic features of VACTERL association. Confirming a diagnosis is important as it can help with the identification of other possible associated medical diagnoses. Unless there are several very severe defects, babies with VACTERL association do well and can lead normal, productive lives.