Fetal Treatment of Galenic Malformations

The study involves a single fetal intervention of maternal transuterine, fetal transcranial torcular puncture and median prosencephalic vein embolization. Detachable platinum coils (Target XL and XXL Detachable Coil, Stryker Neurovascular) will be used to pack the prosencephalic varix. This procedure will take place in an obstetric OR at Brigham and Women's Hospital. Data will be collected every 4 weeks post-procedure until delivery, as per standard of care. Data regarding delivery and post-delivery status will also be collected until the subject is discharged from the hospital. After delivery, neurological assessments will be performed every 6 months for 2 years (adjusted for gestational age). Data will be compared to historical cohorts.

• Fetal embolization of vein of Galen malformation using Target XL and XXL Detachable Coils (Device): The study involves a single fetal intervention of maternal transuterine, fetal transcranial torcular puncture and median prosencephalic vein embolization. Detachable platinum coils (Target XL and XXL Detachable Coil, Stryker Neurovascular) will be used to pack the prosencephalic varix.

Primary outcomes

• Prenatal Safety of Fetal Embolization for Patients With Vein of Galen Malformations [From fetal embolization to delivery]: The procedure is deemed safe if 1. None of the following unacceptable events occur within 7 days of fetal embolization: 1. Fetal death 2. Fetal intracranial hemorrhage, either parenchymal or extra-axial, other than petechial hemorrhage. 3. Maternal death 2. None of the following unacceptable events occur between fetal embolization and delivery: 1. Intra-procedural and post-procedural morbidity to the fetus and mother, probably related to the fetal intervention, e.g. placental abruption with subsequent sequelae 2. Preterm delivery < 28 weeks, probably related to the fetal intervention 3. Maternal blood transfusion or unanticipated surgical intervention, probably related to the fetal intervention 4. Presence of fetal imaging evidence of new brain injury in a location or pattern unexpected for the natural history of vein of Galen malformation, probably related to the fetal intervention

Secondary outcomes

• Efficacy of Fetal Embolization for Patients With Vein of Galen Malformations [Within 30 days of birth]: The procedure is deemed efficacious if none of the following serious postnatal events occur within 30 days of birth: 1. Urgent neonatal embolization is needed. Without fetal intervention, we'd expect 80% of the cohort to require such intervention. 2. Neonatal death. Without fetal intervention, we'd expect a mortality rate of 40% in this cohort. 3. Brain MRI within the first three weeks after birth reveals parenchymal brain injury (acute infarct or gliosis) affecting > 10% of the supratentorial brain volume. Without fetal intervention, we'd expect 30% of patients in this cohort to show this kind of injury.

Sex: Female, ages: 18 Years to any

Inclusion Criteria:

* Pregnant woman carrying a fetus harboring a vein of Galen malformation in whom the straight sinus or falcine sinus draining the prosencephalic varix measures 7 mm or more on fetal MRI (medio-lateral diameter measured at the narrowest point of the sinus along the rostral-caudal axis, assessed on a T2-weighted coronal slice).
* Fetal gestational age between 23 weeks and term as determined by clinical information and evaluation of first ultrasound.
* Anatomic diagnosis of fetal vein of Galen malformation.
* Well preserved brain parenchyma.
* Maternal age of 18 years and older.
* Eligible for continuous lumbar epidural anesthesia.
* Able to travel to study site for study evaluation, procedures and visits.

Exclusion Criteria:

* Extensive fetal brain parenchymal injury/gliosis, >10% of supratentorial brain volume (i.e., SFP presentation). This is a degree of fetal brain injury beyond which the risk of significant neurological morbidity is high, based on studies of prenatal ischemic stroke.
* Irreversible fetal non-brain organ injury (e.g. hydrops fetalis as a manifestation of heart failure, a finding which portends fatal outcome in fetuses with vein of Galen malformation), i.e., SFP presentation.
* Fetus with VOGM in whom the straight sinus or falcine sinus draining the prosencephalic varix measures less than 7 mm on fetal MRI (T2-weighted coronal slice, medio-lateral diameter measured at the narrowest point of the sinus along the anterior-posterior axis), fitting fetal MRI criteria for likely evolution into the IT cohort.
* Severe maternal obesity pre-pregnancy as defined by body mass index (BMI) of 40 or greater.
* Fetuses with major congenital anomalies.
* Evidence of preterm labor, rupture of membranes or abruption.
* Maternal coagulopathy: INR > 1.2; PT/PTT above normal ranges for the lab; platelets <100.
* Medical disease requiring current anticoagulation including maternal deep vein thrombosis.
* Prior maternal medical history that would preclude epidural anesthesia.
* Multi-fetal pregnancy.
* Placenta previa or accreta.
* Participation in another fetal study that influences maternal and fetal morbidity and mortality.
* Known maternal hypersensitivity to 316LM stainless steel.
* Supine hypotensive syndrome.

Participant flow

Outcome results

• Prenatal Safety of Fetal Embolization for Patients With Vein of Galen Malformations (Primary), Count of participants, Participants: Fetal Embolization of Vein of Galen Malformation 5
• Efficacy of Fetal Embolization for Patients With Vein of Galen Malformations (Secondary), Count of participants, Participants: Fetal Embolization of Vein of Galen Malformation 2

Adverse events

Time frame: Adverse events were collected from the time of enrollment through 2 years post-delivery.

Serious adverse events by term

Other adverse events by term

• Results publication: Orbach DB, Shamshirsaz AA, Wilkins-Haug L, Guseh S, Krispin E, Tworetzky W, O'Leary B, Larson AM, Rangwala SD, Oushy S, See AP. In Utero Embolization for Fetal Vein of Galen Malformation. JAMA. 2025 Sep 9;334(10):878-885. doi: 10.1001/jama.2025.12363. PMID 40788723
• Results publication: Orbach DB, Wilkins-Haug LE, Benson CB, Tworetzky W, Rangwala SD, Guseh SH, Gately NK, Stout JN, Mizrahi-Arnaud A, See AP. Transuterine Ultrasound-Guided Fetal Embolization of Vein of Galen Malformation, Eliminating Postnatal Pathophysiology. Stroke. 2023 Jun;54(6):e231-e232. doi: 10.1161/STROKEAHA.123.043421. Epub 2023 May 4. No abstract available. PMID 37139817
• Results publication: See AP, Wilkins-Haug LE, Benson CB, Tworetzky W, Orbach DB. Percutaneous transuterine fetal cerebral embolisation to treat vein of Galen malformations at risk of urgent neonatal decompensation: study protocol for a clinical trial of safety and feasibility. BMJ Open. 2022 May 24;12(5):e058147. doi: 10.1136/bmjopen-2021-058147. PMID 35613814

• Study Protocol and Statistical Analysis Plan (PDF, 2023-12-11)

• Darren Orbach, MD PhD, Principal investigator, Boston Children's Hospital