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Chapters
0:00 Introduction
1:36 causes of Congenital Pulmonary Airway Malformation
1:49 symptoms of Congenital Pulmonary Airway Malformation
1:59 diagnosis and treatment for Congenital Pulmonary Airway Malformation
2:58 treatment of Congenital Pulmonary Airway Malformation
Congenital pulmonary airway malformation (CPAM), formerly known as congenital cystic adenomatoid malformation (CCAM), is a congenital disorder of the lung similar to bronchopulmonary sequestration. In CPAM, usually an entire lobe of lung is replaced by a non-working cystic piece of abnormal lung tissue. This abnormal tissue will never function as normal lung tissue. The underlying cause for CPAM is unknown. It occurs in approximately 1 in every 30,000 pregnancies.[1]
In most cases the outcome of a fetus with CPAM is very good. In rare cases, the cystic mass grows so large as to limit the growth of the surrounding lung and cause pressure against the heart. In these situations, the CPAM can be life-threatening for the fetus. CPAM can be separated into five types, based on clinical and pathologic features.[2] CPAM type 1 is the most common, with large cysts and a good prognosis. CPAM type 2 (with medium-sized cysts) often has a poor prognosis, owing to its frequent association with other significant anomalies. Other types are rare.[3]
Three quarters of affected patients are asymptomatic. However, 25% develop cyanosis, pneumothorax, and show signs of increased breathing difficulty (tachypnoea and intercostal retractions).At examination, they may show hyper-resonance at percussion, diminished vesicular murmur and an asymmetrical thorax.[citation needed]
In most cases, a fetus with CPAM is closely monitored during pregnancy and the CPAM is removed via surgery after birth.[5] Most babies with a CPAM are born without complication and are monitored during the first few months. Many patients have surgery, typically before their first birthday, because of the risk of recurrent lung infections associated with CPAMs. Some pediatric surgeons can safely remove these lesions using very tiny incisions using minimally invasive surgical techniques (thoracoscopy). However, some CPAM patients live a full life without any complication or incident. It is hypothesized that there are thousands of people living with an undetected CPAM. Through ultrasound testing employed in recent years, many more patients are aware that they live with this condition. Rarely, long standing CPAMs have been reported to become cancerous.[citation needed]
Very large cystic masses might pose a danger during birth because of the airway compression. In this situation, a special surgical type of delivery called the EXIT procedure may be used.
In rare extreme cases, where fetus's heart is in danger, fetal surgery can be performed to remove the CPAM. If non-immune hydrops fetalis develop, there is a near universal mortality of the fetus without intervention. Fetal surgery can improve the chances of survival to 50-60%. Recently, several studies found that a single course of prenatal steroids (betamethasone) may increase survival in hydropic fetuses with microcystic CPAMs to 75-100%.[6][7] These studies indicate that large microcystic lesions may be treated prenatally without surgical intervention. Large macrocyst lesions may require in utero placement of a Harrison thoracoamniotic shunt.
