Thoracoamniotic Shunts in Macrocystic Lung Lesions: Case Series and Review of the Literature

Objective: To evaluate the efficiency of thoracoamniotic shunts for drainage of macrocystic-type congenital cystic adenomatoid malformation (CCAM). Subjects and Methods: This was a retrospective study of 12 fetuses with a large thoracic cyst treated with thoracoamniotic shunting between 2004 and 2014 in a tertiary fetal therapy center. Medline was searched to identify cases of CCAM treated with thoracoamniotic shunting. Results: In all cases the thoracic cyst was associated with major mediastinal shift, the CCAM volume ratio (CVR) was >1.6, and in eight cases there was associated hydrops. Shunt insertion was successfully carried out in all cases at a median gestational age of 24 weeks (range 18-34). In 10 cases there was live birth at a median age of 38 weeks (range 35-41), but in two hydropic fetuses there was intrauterine death. A literature search identified a total of 98 fetuses with CCAM treated with thoracoamniotic shunting between 1987 and 2016. In the combined data from the previous and the current study, the survival rate was 77% (53 of 69) for hydropic and 90% (37 of 41) for nonhydropic fetuses. Conclusions: The role of thoracoamniotic shunting in macrocystic lung lesions associated with hydrops is well accepted. Intrauterine intervention is also likely to be beneficial in the subgroup of nonhydropic fetuses with a CVR >1.6.