AMNIOTIC BAND SYNDROME

Amniotic band syndrome, aka constriction ring syndrome, occurs when fibrous bands of the amniotic sac tangle around a developing fetus.

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Amniotic Band Syndrome

Amniotic band syndrome, aka constriction ring syndrome, occurs when fibrous bands of the amniotic sac tangle around a developing fetus. The amniotic sac refers to the lining inside the uterus that contains a fetus. In most cases, the bands wrap around the arm, leg, fingers, or toes. However, in certain rare cases, the bands may also wrap around the head of the fetus or umbilical cord. Acting just like a tight rubber band around the body part, this can cause serious tightening or constrictions, hindering the proper growth of that part. Most children with amniotic band syndrome usually have bands on multiple body parts.

How Common is Amniotic Band Syndrome?

Researchers report that Amniotic band syndrome affects about one out of every ten thousand to fifteen thousand babies. According to the doctors, it happens more often in the fingers than in the toes.

Symptoms of Amniotic Band Syndrome

While the amniotic band might only lead to a small dent around a finger or limb, deeper bands can result in serious swelling, hinder blood flow, or prevent that part of the body from growing properly. Moreover, if a constriction is tight enough, the band may also cause an in-utero amputation. It means part of the body comes off before birth.

The symptoms related to amniotic band syndrome vary considerably from one infant to another. While some infants develop only mild deformities, others might develop severe malformations that could even be life-threatening. The features of amniotic band syndrome develop primarily in the first trimester (first 12 weeks) of pregnancy.

Experts have identified various patterns associated with amniotic band syndrome (ABS). The three most common types are:

Amniotic band syndrome with one or more affected limbs
The limb-body-wall complex
Characterized by head and face-related abnormalities (craniofacial abnormalities), brain defects, and serious arm and leg malformation.

QUESTIONS AND ANSWERS

What is Amniotic Band Syndrome?

Amniotic Band Syndrome (ABS) is a rare congenital condition that occurs during fetal development. It happens when fibrous bands from the amniotic sac become entangled around the developing fetus, restricting the blood flow and proper growth of certain body parts. ABS can affect various body structures, such as limbs, fingers, toes, or even internal organs, leading to a wide range of physical abnormalities.

What causes Amniotic Band Syndrome?

The exact cause of Amniotic Band Syndrome is not entirely understood. It is believed to occur randomly during the early stages of pregnancy when the inner layer of the amniotic sac ruptures, and fibrous bands form and adhere to the developing fetus. There are no known lifestyle or environmental factors that increase the risk of ABS, and it is not usually related to any actions or behaviors of the expectant mother.

How is Amniotic Band Syndrome diagnosed and treated?

Amniotic Band Syndrome is typically diagnosed during routine prenatal ultrasounds when physical abnormalities are detected in the fetus. After birth, a comprehensive physical examination and medical imaging may confirm the diagnosis and identify the extent of the condition. Treatment for ABS varies depending on the severity of the abnormalities and the structures affected. In some cases, no intervention is necessary if the bands cause minimal impact on the child’s health. However, surgical intervention may be required to release or reconstruct affected body parts to improve function and appearance.

Specialized Programs for ABS Care

For families seeking specialized care for Amniotic Band Syndrome, several programs focus on treating congenital anomalies and related conditions:

Fetal Care and Surgery Center: This center offers advanced diagnostics, surgical, and medical treatments for congenital anomalies, providing essential care from prenatal stages through postnatal interventions.
Hand and Reconstructive Microsurgery Program: This program excels in managing both congenital and acquired hand deformities, offering cutting-edge surgical solutions to improve hand function and appearance.
Limb Lengthening and Reconstruction Program: Serves children with limb differences, focusing on innovative techniques to address discrepancies and improve mobility.
Pediatric Rehabilitation Medicine Program: Aims to optimize daily function, ensuring children receive tailored rehabilitation to enhance their quality of life.

If your baby is born with Amniotic Band Syndrome, call us and our team will help your baby. Through these comprehensive programs, we strive to deliver personalized and effective care to each child.

If your baby is born with Amniotic Band Syndrome, call us and our team will help your baby

Affected Limbs

Most infants with amniotic band syndrome have some sort of deformity in the arms, legs, fingers, or toes. One or more limbs may be malformed. And upper limbs are affected more often than lower limbs. However, in some patients, only one limb may be the only symptom of ABS.

The particular physical features may be:

Abnormally short fingers
Toes without the end (distal)
Webbing (fusion) of fingers or toes (syndactyly)
Constriction rings and extra strands of tissue adhere to the fingers.

The constriction rings surrounding a limb or digit can hinder blood flow.

Limb-body Wall Complex

Another pattern related to amniotic band syndrome is the limb-body wall complex, a lethal condition. In this condition, the affected infants have:

Protrusion of a part of the brain and the surrounding membranes (meninges) through the defect of the skull (encephalocele)
Facial clefts
Protrusion of the viscera (the soft internal organs in the abdominal or chest cavities) through a fissure in the abdominal wall (Abdominoschisis) or the chest wall (Thoracoschisis)

Also, there might be various other defects affecting the arms and legs.

Craniofacial Abnormalities

This pattern of amniotic band syndrome involves craniofacial abnormalities:

Cleft palate
Facial clefts
Microphthalmia – Small, underdeveloped eyes
Choanal atresia – Narrowing of the nasal passages
Malformations in the size and shape of the skull. In some infants, the head can be adjoined with the placenta.

Causes of Amniotic Band Syndrome

Well, the exact cause of the syndrome is not clear. Doctors do not consider amniotic band syndrome hereditary. Many cases seem to occur for no clear reason. The causes and underlying mechanisms causing ABS are pretty complex and controversial. There are different theories explaining the complex mechanisms of this syndrome. The two major theories are:

The extrinsic theory: This theory states that ABS occurs because of the factors found outside of the fetus (externally)

The intrinsic theory: This theory depicts that amniotic band syndrome happens due to factors within the fetus (internally).

Diagnosis

ABS is usually diagnosed at or soon after birth depending on finding certain physical characteristics. The basic diagnostic criteria include detecting specific abnormalities of the arms, legs, fingers, and/or toes. These abnormalities include amputation defects, ring-like constriction, fusion (syndactyly) between some digits, strands of tissue attached to the affected fingers, etc.

Sometimes, doctors can suspect the condition before birth (prenatally), depending on the results of advanced imaging techniques. For example, Fetal ultrasonography may reveal characteristic defects. In Fetal ultrasonography, experts use reflected high-frequency sound waves to create an image of the developing fetus.

Treatment for Amniotic Band Syndrome

The treatment options for ABS are in-utero fetal surgery and postnatal repair of the resulting abnormalities.

Fetal surgery: The objective of fetal surgery is to release the constriction ring that the amniotic band develops before it causes further damage. Doctors do this by operative fetoscopy, which offers direct visualization of the amniotic band. Also, this procedure helps release those bands by using different surgical techniques.

The success of fetal surgery depends on the level of damage caused by the amniotic band. In case the extremity’s distal part is swollen, releasing the band resolves the swelling and allows normal development to continue. And, if the constriction seems more severe, releasing the band can prevent further damage. Also, it will prevent amputation of the affected extremity.

Treatment after birth: This includes plastic and reconstructive surgery. Also, physical and occupational therapy will be necessary depending on the type of deformity. Doctors may also recommend prosthetics for children suffering from loss of limbs. Advancements in 3-D printing help create more functional prostheses for these patients.

Now, deciding which treatment will be the most appropriate for a patient needs a detailed assessment. For evaluation, doctors use high-resolution 2-D and 3-D ultrasounds. Also, they examine the blood supply of the affected limb and do additional magnetic resonance imaging (MRI).

Will ABS Affect the Long-term Health of My Child?

The long-term effects are different for everyone. It depends on the affected body parts and the severity of the condition. For some lucky patients, doctors can surgically repair or address the limbs and birth defects with interventions. It helps restore function and does not affect overall health. However, in more severe cases, ABS can cause permanent or life-threatening problems.

What will Happen after Birth?

A child with amniotic bands syndrome may need treatment after birth. Reconstructive surgery will be necessary to correct those deep constriction rings, cleft lips, fused fingers or toes, clubbed feet, etc. Your child might need minor and complicated surgeries depending on the ABS-related deformities.

What to Expect During Surgery

Usually, surgeons make incisions in the skin along the band. Thus, they remove extra or fragile skin from the crease in the soft tissue of the baby. In the next step, the surgeon will make zig zag cuts in the skin above and below the band. This procedure is called Z-plasty, which creates pointed flaps of skin. Then experts give a more normal contour to the soft tissue under the skin. In the last stage, the surgeon brings the flaps of skin together and closes the incisions. The zigzag method prevents scar. Do not miss follow-up visits. It will help doctors make sure the cuts are healing well.

Final Words

In most cases, you can discuss your options with a plastic surgeon soon after birth. At the Medical City Children’s Orthopedics and Spine Specialists, with offices in Dallas, Arlington, Flower Mound, Frisco, and McKinney, TX we take pride in our highly accomplished team of pediatric orthopedic surgeons who will treat your child.

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Footnote:

National Organization of Rare Diseases: Amniotic Band Syndrome

Call 214-556-0590 to make an appointment.

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