Vacterl Syndrome

What is Vacterl Syndrome?

Vacterl Syndrome is considered as a congenital defect, which affects multiple organ structures. Each letter of Vacterl is representing the affected anatomical structure, which can be illustrated as

• ‘V’ stands for vertebral abnormalities
• ‘A’ stands for anal atresia
• ‘C’ stands for cardiac defects
• ‘TE’ stands for tracheal-esophageal anomaly and that includes stenosis, atresia, and fistula
• ‘R’ stands for radial and renal abnormalities
• ‘L’ stands for limb abnormalities
• ‘S’ stands for single umbilical artery

Vacterl Syndrome alternatively also known as VATER Syndrome; because in this case, the affected children may have Vertebrae (V), Anus (A), Trachea (T), Esophagus (E), Renal (R) abnormalities. Although it is not necessary that the child affected with Vacterl Syndromeor VATER Syndrome possess all the abnormalities, however, many of the abnormalities with concern areas are associated withVacterl Syndrome^1,2.

Symptoms

Vacterl Syndrome defects are noticeable at the time of birth and some are also analyzable through prenatal ultrasound. However, some of the defective characteristics of Vacterl Syndrome are apparent at the later stage of life.

Experts usually considered abnormality in any three involved body parts i.e. thorax, lower abdomen or pelvis and limbs with the probable presence of two or more anomalies represent Vacterl Syndrome. The nature of symptoms and severity differs from child to child. The bellow enlisted all the symptoms may not occur in every case.

Abnormalities

Different characteristic features associated with Vertebral abnormalities are missing of vertebrae, abnormal curvature (scoliosis), cleft in vertebrae or fused vertebrae. Sometimes the deformity of vertebrae extends to the forward direction and provide associated ribs abnormality like the absence of ribs, the presence of additional ribs, fused ribs or splitting of ribs. Apart from these, some child may have an absence of the tailbone, sacral agenesis etc.

Anal Atresia

Anal atresia is a structural deformity of the anal canal, which can be described as a thin skinny layer obstructs the opening of the anal canal. It can also describe as the channel through which anus connects with rectum (the last part of the large intestine) fails to develop.

This condition leads to the obstacle of the bowel contents passage. Experts also assume that this structural deformity increases the risk of genital abnormalities and may cause serious issue specifically in boys.

Cardiac Defects

The ventricular septal defects (VSDs) is a common cardiac defect associated with Vacterl Syndrome affected children. In ventricular septal defects, the fibrous partition (septum) between ventricles (the lower chambers) is deformed at any part of the ventricular septum. The severity of the symptom is depended upon the extent and position of the defect.

The included symptoms are tachypnea ( rapid rate of breathing), wheezing, tachycardia (fast heartbeat), retarded expected physical growth and/or other. But symptoms are mild in the case of smaller size defects, but life-threatening outcome associated with the large defect.

Esophageal Atresia and/ or Tracheoesophageal Fistula

Esophagus or food pipe which carries food from mouth to stomach are not properly formed and the terminated part of the pipe become narrow or form a pouch and unable to transfer the food from mouth to stomach and termed as esophageal atresia.

In tracheoesophageal fistula, the fistula causes food enters from the stomach to the windpipe or lungs and that cause a respiratory infection like pneumonia. Feeding and swallowing problem occur in these conditions.

Renal Abnormalities

The renal abnormalities in Vacterl Syndrome include renal aplasia (absence of one kidney), renal dysplasia (defect of one or both kidneys), renal ectopia (dislodging or displaced kidneys), reflux or backflow of urine from bladder to urine (vesicoureteral reflux) and that cause anomalous accumulation of urine in the kidneys (hydronephrosis).

The affected child frequently gets tract infections and also has hypospadias, in which the urethral opening may not be at the end of the penis.
Limb Anomalies

Vacterl Syndrome associated with defects in radius bone (lower arm bone) on the thumb side and also restrict the growth of the radius bone (radial hypoplasia) and that may cause underdeveloped or absence of the thumb. Even the abnormality may cause an extra bone in the thumb (triphalangeal thumb).

Apart from these, other limb abnormalities are polydactyly (extra digits), syndactyly (webbing of the digits), abnormal fusion of the two forearm bones (radiaoulnarsynostosis) and lower limb malformations (such as clubfoot, and hypoplasia of the great toe and tibia). Some children also have growth retardation^1,4.

 Causes

The precise reason of progression Vacterl Syndrome is now unclear. Yet now no specific abnormal genetic or environmental involvement identified. The incidence of Vacterl Syndrome indicates the development of the associated abnormalities is random without having any apparent reason or sporadic. Rarely in the same family, more than one member is affected with Vacterl Syndrome. Therefore, the chance of hereditary involvement is negligible.

The researcher assumes that the Vacterl Syndrome abnormalities are resultant of the defects occur in the mesodermal layer (middle) layer of the embryo during the development of the fetus. In the prenatal development, a heterogeneous affront during the period of initial 2 to 4 weeks of gestation associated with Vacterl Syndrome.

The predominance of the development of this syndrome provides the indication that diabetic females are frequently given childbirth with Vacterl Syndrome features than the general population.

Few case history of Vacterl Syndrome analysis represented that abnormal mutation of the FGF8 gene and mitochondrial DNA have been associated with the Vacterl Syndrome development. In some chromosomal disorders including trisomy 18 syndrome or Fanconi anemia are possess multiple Vacterl Syndrome features^1,3.

Treatment

A group of experts can treat Vacterl Syndrome affected children. Depending upon the complexity of the Vacterl Syndrome is managed in two different phases

In the first phase, the experts mainly concentrate on the life-threatening symptoms or cause incompatibility of life, including severe cardiac malformations,  tracheo-esophageal fistula, and imperforate anus. The surgical intervention is the only way to manage these symptoms. For example, colostomy and subsequently re-anastamosis and “pull-through” surgery are performed for rectification of imperforate anus.

In the second phase, the considerable symptoms are usually provided long term trouble like vertebral anomalies can cause back pain in the later stage of life, so may require prolonging treatment for pain management; renal abnormalities often cause frequent urinary infection, renal calculi or renal impairment and that also require chronic medical support to manage the condition.

Therefore, treatment of Vacterl Syndrome is symptom specific and a coordinated care followed by a panel of expert require to manage Vacterl Syndrome^4,5,6.

Life Expectancy

Life expectancy depends on the complexity of the symptoms associated with Vacterl Syndrome. In the case of severe cardiac complication, the risk of premature death is more, though successful surgeries can improve the life expectancy of Vacterl Syndrome affected child^4,5,6.

References

1. VACTERL Association; National organization for Rare Disorders; Retrieve from https://rarediseases.org/rare-diseases/vacterl-association/
2. VACTERL association; Genetic Home References; https://ghr.nlm.nih.gov/condition/vacterl-association
3. VACTERL Association; http://www.webmd.com/children/vacterl-association
4. Benjamin D Solomon; VACTERL/VATER Association; Orphanet J Rare Dis. 2011; 6: 56. Published online 2011 Aug 16. doi: 10.1186/1750-1172-6-56; https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3169446/
5. Levitt MA, Peña A. Anorectal malformations. Orphanet J Rare Dis. 2007;2:33. doi: 10.1186/1750-1172-2-33. 
6. Raam MS, Pineda-Alvarez DE, Hadley DW, Solomon BD. Long-term outcomes of adults with features of VACTERL association.