Congenital Pulmonary Airway Malformation
A CPAM (formerly referred to as a CCAM or Congenital Cystic Adenomatoid Malformation) is a cystic mass which forms in the lung tissue of a baby in the womb. This mass is usually located in one lung, preventing the lung from growing normally. A CPAM may also cause the heart to shift to the opposite side of the chest or push downward on a baby’s diaphragm.
At SSM Health Cardinal Glennon St. Louis Fetal Care Institute, our team treats the whole condition, both monitoring your baby’s lungs and heart, and providing a comprehensive medical solution.
If your baby has been diagnosed with a CPAM, you can rely on our dedicated, multidisciplinary team of providers to care for your child’s every need. We coordinate and provide prenatal care and monitoring, immediate care after delivery in our NICU (Neonatal Intensive Care Unit) as well as long-term follow-up care with our experienced pediatric surgeons as your child’s lungs continue to develop.
How is CPAM Diagnosed?
A CPAM is detectable during a routine prenatal ultrasound. It actually appears as a bright mass in the area of the chest where only lung tissue should be seen.
We are able to confirm this diagnosis using advanced fetal MRI to better identify the size and location of the defect. We may also perform a fetal echocardiogram (echo) to rule out any structural heart defects and assess heart function.
How Does CPAM Affect My Baby?
In a small number of cases, a CPAM may grow so rapidly that it becomes life-threatening before birth. This usually happens between 18 and 26 weeks gestation. The large mass causes compression, leading to heart and lung failure. To prevent this from happening, either fetal surgery or early delivery is necessary.
In the vast majority of cases however, babies do well and have normal development and lung function. That’s because during the pregnancy, the growth of the cyst usually starts to slow down in the second trimester. Sometimes, the mass becomes very small and undetectable. It is always there, but studies will have to be done after birth to find the CPAM. In these cases, the outlook for a normal life is excellent.
How is CPAM Managed During Pregnancy?
During the initial ultrasound, we will measure the volume of the CPAM relative to the size of your baby. The ratio we use is called the CPAM volume ratio, or CVR. For every fetus with a CPAM, we start by measuring the CVR every week.
By comparing the CVR measurements, we can determine how fast the CPAM is growing and whether it will become life-threatening. If the CPAM remains small after 28 weeks (a CVR measurement of less than 1), we’ll monitor it through an ultrasound every three to four weeks until delivery.
If the defect is pushing the heart out of the normal position, we may perform a second MRI around 32-34 weeks of pregnancy and monitor the heart with an echocardiogram twice a week.
Babies with a very large CPAM (a CVR measurement larger than 1) need to be followed very closely to watch for declining heart function. Usually, ultrasound exams need to be performed twice a week and repeated echos may also be performed.
In severe cases, we may recommend one, or a combination of interventions:
- Steroids to slow or stop the growth of the mass
- Open fetal surgery to remove the mass
- Drainage of the fluid-filled cysts using a special needle
- Early delivery starting at 32 weeks of pregnancy
How is CPAM Treated After Delivery?
Depending on the severity of the CPAM, your newborn may have difficulty breathing at delivery. If this is the case, we’ll move them to our NICU where they will be cared for as if they were our own. For infants who have the cyst surgically removed, the long-term outlook is excellent. In most cases, infants with a relatively small CPAM will have fewer complications and can go home after delivery.
Rarely, a CPAM is so large that we anticipate the baby will have problems breathing right at birth. We try to predict this based on the size of the CPAM and lungs by MRI, and the degree that the heart has been pushed out of the way. To avoid a crisis in the baby’s breathing at birth, we recommend that a special delivery method called an EXIT procedure be used. During this delivery, the baby remains connected to the placenta and umbilical cord while we evaluate lung function. If the baby breathes well, then the baby can be completely delivered and we can plan for removal of the CPAM later. If the baby’s breathing is compromised, then the CPAM can be removed immediately. The chest operation is performed while the mother’s placenta supports the baby. When the operation is finished, the cord is cut and the baby can breathe better without the compression of the CPAM.
What will happen after surgery?
The post-operative course varies depending on when the surgery is done, the size of the CPAM, and how much lung was removed. If the CPAM is removed during the neonatal period, then commonly a breathing tube and intravenous line is needed. The baby may also have a tube in the chest to drain any fluid and help expand the lung into the chest space. The baby will not be able to eat until his or her condition has stabilized but nourishment will be given through the intravenous fluids.
The baby will go home when he or she can breathe sufficiently and eat enough to maintain and gain weight. The average stay for the newborn can range from two to three days for small CPAMs to four to eight weeks for much larger ones. The long-term outcome for infants who have the cyst removed is excellent. These children usually have no limitations on their activities and have no increased risk for respiratory complications.
We understand that CPAM can be a scary diagnosis. That’s why we’re available to help 24 hours a day, 7 days a week. For more information or to schedule an appointment, call us at 314-268-4037 or toll free at 877-SSM-FETL (877-776-3385). You can also email us and one of our trusted representatives will get back to you as soon as possible. Our team is here to develop a comprehensive treatment plan that puts you at ease and gives your baby the best start in life.