VACTERL association

Spine

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 80 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 defects

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.

Cardiac defects

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. It is subsequently thought that cardiac defects should be considered an extension of VACTERL.

Trachea and esophagus

Esophageal atresia with tracheo-esophageal 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 ventricular septal defect, which may not require any surgery.

Kidneys

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 arteries and one vein) which is often associated with additional kidney or urologic problems. Renal abnormalities in VACTERL association 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.

Limbs

Limb defects occur in up to 70 percent of babies with VACTERL association and include a displaced or hypoplastic thumb, extra digits (polydactyly), fusion of digits (syndactyly) and forearm defects such as radial aplasia. 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.

Extension

Features secondary to VACTERL components including single umbilical artery, ambiguous genitalia, abdominal wall defects, diaphragmatic hernia, and anomalies like intestinal and respiratory anomalies, and oligohydramnios sequence defects are frequent enough to be considered an extension of VACTERL.  Cardiac defects are thought to fit in this category.

Growth

Many babies with VACTERL are born small and have difficulty with gaining weight. Babies with VACTERL association, however, do tend to have normal development and normal intelligence.

Pathology

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

Epidemiology

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.

History

The acronym VATER association was first described by Linda Quan, an emergency room physician and David Smith, a man who was considered the father of dysmorphology in 1972  to define a non-random co-occurrence of the listed defects. Years later, research revealed that cardiac and renal abnormalities were common in the association, and the acronym was changed to VACTERL.  The differentiation of the acronyms VACTERL and VATER is due to the variation in defects determined at or prior to birth. VACTERL contains vertebral, anal, cardiac, trachea-esophogeal, renal/kidney, and limb defects where as VATER only has vertebral, anal, trachea-esophogeal, and renal defects. The "R" in VATER represented radial dysplasia.  Though the differences are clear, the visual and physical defects vary from case to case.