What Is a Chylothorax?

A chlylothorax is when chyle (lymphatic fluid) collects in the space around a lung. A chlylothorax (ky-low-THOR-ax) is also called a chylous (KY-luss) effusion.

What Happens in a Chylothorax?

The lymphatic system filters and drains lymph fluid from around the body. Chyle (KYE-ul) is  lymph fluid that contains proteins and fat. The lymphatic system normally brings chyle to a vein in the chest, where it enters the bloodstream.

If part of the lymphatic system leaks or doesn't work right, this normal flow can't happen. When chyle can't get into the blood as it should, it can collect around one or both lungs and form a chylothorax.

What Are the Signs & Symptoms of a Chylothorax?

When there's only a little fluid around a lung, a chylothorax may not cause any symptoms. But as the fluid builds up, it can cause a cough, chest discomfort, or trouble breathing.

What Problems Can Happen?

If a baby develops a chylothorax before birth, the problem can:

• prevent the baby's lung(s) from developing normally
• block blood circulation and lead to heart failure (when the heart is too weak to pump enough blood to the body)
• cause fluid to build up in other parts of the body

Babies or kids with a chylothorax may have trouble breathing well. They also might have other problems, such as trouble fighting infections or gaining weight.

How Is a Chylothorax Diagnosed?

Doctors might suspect a chylothorax in a fetus if a routine prenatal ultrasound shows fluid around the baby's lungs. They'll do more tests to be sure.

If an infant or child might have fluid around the lungs, doctors will order imaging tests. If there is fluid, they'll test it to be sure it is chyle. If it is, they order a radiology test called an MR lymphangiogram (lim-FAN-jee-eh-gram). This lets them see the leak in real time and pinpoint where it is.

How Is a Chylothorax Treated?

If tests show that a fetus has a chylothorax, doctors will watch the mother's pregnancy carefully. When she gives birth, they'll care for the baby in the NICU.

Treating a chylothorax depends on what's causing it. Often, doctors remove fluid from around the lungs. This can help a child breathe more comfortably.

A chylothorax caused by a leak in the lymphatic system may heal on its own. Medicines and a low-fat diet can help the body make less chyle and make a leak more likely to heal. Some kids might need to get IV nutrition — called total parenteral nutrition (TPN). Delivering nutrition into a vein makes the body produce less chyle.

Recently, doctors discovered how to treat these lymphatic leaks or blockages. They can get inside the lymphatic ducts, and block the leaks or find an obstruction. Usually, interventional radiologists do this using very small needles, so kids don't need major surgery.

How Can Parents Help?

To help your child:

• Follow the prescribed diet. It should lower the amount of chyle in the body and help the lymphatic system heal.
• Watch for signs of problems. You know your child best. If your child has new chest pain, a cough, trouble breathing, or a fever, tell your doctor right away.