# Fetal thoracoamniotic shunting for severe macrocystic congenital pulmonary airway malformation with the Somatex® intrauterine shunt: intrauterine course and postnatal outcome

## TL;DR

This study evaluates the use of the Somatex® shunt for treating severe fetal lung malformations, showing high success and survival rates.

## Contribution

The study provides insights into the effectiveness and outcomes of using the Somatex® shunt for fetal thoracoamniotic shunting in macrocystic CPAM.

## Key findings

- The Somatex® shunt achieved high technical success and neonatal survival rates in treating macrocystic CPAM.
- The shunt's design resulted in skin coverage at birth in up to 50% of cases, complicating removal.
- The outcomes with the Somatex® shunt were comparable to other shunt types for this condition.

## Abstract

Thoracoamniotic shunting (TAS) in fetuses with macrocystic congenital pulmonary airway malformation (CPAM) is mostly performed with pigtail shunts like the rocket shunt or the Harrison fetal bladder stent. The aim of this study was to assess the prenatal course, perinatal outcome and complications of TAS for severe macrocystic CPAM using the Somatex® intrauterine shunt.

This was a two center (Cologne/Bonn) observational retrospective study of fetuses that underwent TAS using the Somatex® intrauterine shunt for severe macrocystic CPAM with and without hydrops between 2016–2024. Outcome parameters were perinatal survival, complications, gestational age at delivery and visibility of the shunt outside the skin after birth.

During the study period, 25 fetuses were treated with the Somatex® shunt (13 = Cologne, 12 = Bonn), including 24 singletons and one fetus of a monochorionic-diamniotic twin pregnancy Mean gestational age at intervention was 24.7 weeks (range 19–30). The mean diameter of the dominant cyst within the lesion was 34 mm (range 18–55). Fetal hydrops prior to TAS (ascites and fetal scalp oedema) was present in 36% (9/25). Dislocation in the further course of pregnancy occurred in 8% (2/25) with the need for reintervention in two cases. Resolution of hydrops and regression of the lesion occurred in 96% (24/25). Mean gestational age at delivery was 38.3 weeks (range 26–41), the preterm birth rate < 37 weeks was 20% (5/25), 12% (3/25) were due to PPROM. Live birth rate was 100% and 92% (23/25) of neonates survived the neonatal period. Of the 12 liveborns delivered at the two study centers, in one case the shunt (8.3%) was dislocated in the amniotic cavity, 5 (41.7%) had a visible shunt outside the skin, whereas in the other 6 (50.0%) cases the shunt was covered with skin at birth.

TAS in macrocystic CPAM with the Somatex® shunt has a high technical success rate leading to high neonatal survival rates even in cases associated with hydrops. The intrauterine course and neonatal outcome are comparable to TAS for fetal macrocystic CPAM using other types of shunts. Therefore, the choice of the shunt in macrocystic CPAM can be made freely at the discretion of the physician in charge, the availability of devices and economic factors. Due to the short length of 25 mm and its straight design, the outer end of the Somatex® shunt is covered by skin at birth in up to 50% of cases, which may complicate its removal.