Ventral or midline abnormalities

What are ventral or midline abnormalities?

A ventral or midline abnormality can be best described as a defect that occurs on the anterior (front) portion of a body, usually in the middle or center of the body. Numerous reports of ventral developmental defects (problems that occur before the baby is born) have been described in association with PHACE syndrome. These defects have commonly been observed in the upper portion of the sternum or can extend the entire length of sternum into the abdomen. The sternum is the bone in the middle of the chest wall that joins the two sides of the rib cage.

What ventral or midline defects are seen in children with PHACE syndrome?

thoracic_cage_diagram

Figure 9: Location of sternum within the thoracic cage.

  • Sternal pit is a small indentation or dimple in the skin overlying the sternum of the chest. In some cases, the skin defect can be linear extending several inches over the sternum.
  • Sternal cleft is a birth defect where there is a groove in the sternum. The cleft may be partial or complete, meaning that the sternum is completely separated or only partially split down the center of the bone.
  • Partial or complete agenesis of sternum refers to the partial or complete failure of the sternum to form. Failure of the sternum to form presents a severe problem in that it leaves the vital organs, including the heart and lungs, without the protection of the normally fused ribcage and sternum.
  • Sternal papule is a raised bump on the skin overlying the sternum.
  • Supraumbilical raphe is a scar-like line that extends upward from the umbilicus (belly button). It represents an abnormality of fusion of the layers of the skin.
  • An omphalocele is a condition when the layers of the abdominal wall do not fuse properly and the intestines or other abdominal organs stick out. In babies with an omphalocele, the intestines are covered only by a thin layer of tissue and can be easily seen. Omphaloceles are fixed with surgical procedures.

How common are these defects in PHACE syndrome?

Ventral defects are not seen in all children with PHACE syndrome. The rate of occurrence depends on the type of ventral defect. About 20 percent have a sternal defect, 9 percent have an umbilical raphe, and less than 2 percent of patients have a reported sternal papule.

What specialists may be involved in a child's care for ventral abnormalities?

Depending on the severity of the defect, it is best to visit the primary care physician to diagnose the problem if it has not previously been noticed. After consultation with the primary care physician, a referral to a surgeon may be recommended.