Percutaneous in utero thoracoamniotic shunt creation for fetal thoracic abnormalities leading to nonimmune hydrops

Management dilemma in Thoracoamniotic Shunt Migrations

Shunt migration is a rare but significant complication of thoracoamniotic shunting, an intervention widely used for fetal pleural effusion. We describe a case of a term infant noted antenatally to have fetal hydrothorax that was managed with thoracoamniotic shunting but complicated by shunt migration. We also present the current literature on risk factors, complications and management of intrathoracic shunt migration. The majority of shunt migration cases are managed conservatively with no untoward postnatal sequelae, but surgical removal of the migrated shunt has been used for associated clinical complications, if visceral damage is suspected or if postnatal thoracic surgery is indicated for other reasons. We advocate an approach of conservative management for asymptomatic infants, where possible, to avoid unnecessary surgical and anaesthetic risks to very young, often already compromised children. However, further studies are still required to determine optimal management after shunt migration has occurred to ensure the best outcome.

Perinatal Outcome in Fetuses with Dislodged Thoraco-Amniotic Shunts

OBJECTIVE

Fetal thoraco-amniotic shunts (TASs) can dislodge in utero, migrating internally into the fetal thorax or externally into the amniotic cavity. Our objective was to evaluate the perinatal and long-term outcome of fetuses with TAS dislodgement and conduct a review of the literature.

METHODS

This is a retrospective review of all TAS inserted for primary pleural effusions and macrocystic congenital pulmonary airway malformations (CPAMs) in a tertiary fetal medicine center (1991-2020). Antenatal history, procedural factors, and perinatal and long-term outcomes were reviewed in all fetuses with dislodged shunts and compared to fetuses with shunts that did not dislodge.

RESULTS

Of 211 TAS inserted at a mean gestational age of 27.8 weeks ± 5.47 (17.4-38.1 weeks), 187 (89%) were inserted for pleural effusions and 24 (11%) for macrocystic CPAMs. Shunts dislodged in 18 fetuses (8.5%), 17 (94%) of which were for pleural effusions. Shunts migrated into the chest wall/amniotic cavity or into the thorax among 7/18 (39%) and 11/18 (61%) fetuses, respectively. Eleven (61%) fetuses were initially hydropic, which resolved in 8 (72%) cases. Effusions were bilateral in 9 (50%), amnioreduction was required in 6 (33%), and fetal rotation in 8 cases (44%). Four (22%) fetuses underwent repeat shunting, 12 (67%) neonates required ventilatory support, and 2 (11%) neonates required chest tubes. There was no significant difference in technical factors or outcomes between infants with shunts that dislodged and those that did not. Among 11 intrathoracic shunts, 2 (18%) were removed postnatally and the remainder are in situ without any shunt-related or respiratory complications over a follow-up period of 9 months to 22 years.

CONCLUSION

TAS dislodged antenatally in 8.5% of fetuses, with 2/3 of shunts migrating into the thorax, and nearly 25% requiring re-shunting. Retained intrathoracic shunts were well tolerated and may not necessarily require surgical removal after birth.

Unique Considerations: Preterm Prelabor Rupture of Membranes in the Setting of Fetal Surgery and Higher Order Pregnancies

Two unique aspects of antenatal care occur in the setting of fetal surgery and multiple gestations. As fetal interventions increase, so do the number of cases of iatrogenic preterm prelabor rupture of membranes (PPROM). Because of the amniotic sac's inability to heal, the risk of PPROM after surgery is directly correlated with the number of interventions, the size of the defect, and the surgery performed. Higher order gestations also carry an increased risk of PPROM. This paper reviews the risks and management of PPROM in the setting of the various prenatal interventions as well as in the setting of multiple gestations.