*4.2.3. Surgical resection*

For solid or mixed solid/cystic CPAM with a large solid component, in-utero open resection has been successfully performed. Following resection, hydrops resolves over 1 to 2 weeks with reversal of the mediastinal shift over 3 weeks [61]. Maternal-fetal surgery requiring hysterotomy appears to be associated with an increased risk of premature labor, premature rupture of membranes, and subsequent pregnancy (uterine dehiscence or rupture) [61]. Percutaneous laser ablation of solid CPAM has been reported in only a few case reports and further research is warranted [61].

### *4.2.4. Sclerotherapy*

A single study described fetal sclerotherapy in three patients under 26 weeks with CPAM and hydrops, severe mediastinal shift, and polyhydramnios [67]. Sclerotherapy was performed with percutaneous injection of Ethamolin (ethanolamine oleate) or Polidocanol (aethoxysklerol) into the mass under ultrasound guidance using a 22-gauge needle [61]. Resolution of hydrops and of the mass effect was observed in all cases. The patients were delivered at term without complications. Further studies are indicated to assess the risks and benefits of this innovative technique [67].

#### *4.2.5. Delivery management*

If the lung mass has resolved or is small with no mediastinal shift or hydrops, CPAM itself is not an indication for early delivery or cesarean delivery [61]. Neonatal respiratory problems would be unlikely, but the delivery should be recommended in a tertiary care center. For fetuses with large masses that cause mediastinal shift and/or hydrops, delivery should be planned for a tertiary care center with an intensive care nursery capable of resuscitation of a neonate with respiratory difficulties, including capability of extracorporeal membrane oxygenation (ECMO), and with pediatric surgeons experienced in care of these infants [61]. If hydrops develops after 32 weeks of gestation, early delivery is recommended, possibly with the use of EXIT [61]. In EXIT, the fetus is partially delivered and intubated without clamping the umbilical cord. Uteroplacental blood flow and gas exchange are maintained by using inhalational agents to provide uterine relaxation and amnioinfusion to maintain uterine volume. This provides time for resection of the lung mass prior to complete delivery of the infant in rare instances or, more often, cannulation for extracorporeal membrane circulation, thus creating a controlled situation for delayed removal of the CPAM. Overall fetal survival of 90% has been reported [61].
