[size=20px]A 20 week old fetus is diagnosed with macrocystic CPAM (dominant cyst) with CVR of 1.2. The screening ultrasound did not show any evidence of fetal hydrops or polyhydramnios. At 24 weeks, CVR was calculated at 1.8 and there is evidence of ascites, pleural effusion, and pericardial effusion. The best next step for this fetus with CPAM is

 

A Immediate induction to natural delivery

 

B Placement of thoracoamniotic shunt

 

C Immediate EXIT procedure

 

D Repeat ultrasound at 28 weeks

 

E Administration of maternal steroids[/size]

B

B

B

B

B

B

B

B

I would say E then B.. Because B has a risk of inducing birth, E would help in "ripening" the lungs before going to fetal surgery

Correct answer

B Placement of thoracoamniotic shunt

 

Large macrocystic congenital pulmonary airway malformation (CPAM) may cause pulmonary hypoplasia due to compression of developing lung tissue and non-immune fetal hydrops due to caval compression, tamponade physiology, or mediastinal displacement. Unlike microcystic lesions, macrocystic lesions do not respond to maternal steroids. In fetuses with macrocystic lesions with fetal hydrops or signs of evolving hydrops, polyhydramnios, CVR >1.6 or rapidly increasing cyst – such as this case – thoracoamniotic shunting should be considered.

 

A systematic review on the use of thoracoamniotic shunt demonstrated an improved survival rate of 62% (15 of 24) in treated hydropic fetuses versus 3% (1 of 33) in the untreated ones (odds ratio, 19.28; 95% confidence interval, 3.7–101). In a recent review of a total of 110 fetuses with CPAM treated with thoracoamniotic shunting between 1987 and 2016, the survival rate was 77% (53 of 69) for hydropic and 90% (37 of 41) for nonhydropic fetuses.