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CME Credit Offered
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Abstract Award
Abstract Award

Oral Concurrent Session 8 - Fetus and Fetal Intervention

Oral Concurrent Sessions

Oral Concurrent Session 8 - Fetus and Fetal Intervention

(93) In-utero ventriculosubgaleal shunt placement - a fetal lamb model of induced hydrocephalus

Saturday, February 1, 2025
9:45 AM - 10:00 AM  
Location: Aurora Ballroom B, Lobby Level
Objective: Irreversible brain damage due to congenital hydrocephalus may be improved with prenatal intervention. While ventriculosubgaleal shunting (VSGS) is commonly performed postnatally in premature infants, in-utero placement is unexplored. For the first time, we evaluate the feasibility of VSGS in-utero using a lamb model.

Study Design: Hydrocephalus was induced in 14 fetal lambs by injecting 1.5 mL of BioGlueⓇ into the cisterna magna (Fig 1a-1d) between days 80-90 of gestation. Ten to 16 days later, ultrasound was performed to confirm hydrocephalus. Afterward, VSGS was placed by creating a subgaleal pocket (Fig 1e), inserting a standard ventricular catheter (Fig 1f), tunnelling under the scalp (Fig 1g), and securing with a silk suture (Fig 1h), with the other end in a lateral ventricle (Fig 1i). Near term, the ewes were sacrificed. Hysterotomy was performed to extract the lambs. Lambs were evaluated through gross inspection, and postmortem MRI was performed. Neuropathology is pending.

Results: Ten ewes with 14 fetuses underwent hydrocephalus induction (median 86 days) by either hysterotomy (2/14) or transuterine (12/14) methods. Two fetuses were macerated, but hydrocephalus was confirmed in 11/12 surviving fetuses (3 severe, 4 moderates, 4 mild). A VSGS was successfully placed in all 12 (median 104 days) (Fig 1e-1h). One with severe hydrocephalus died after the procedure, 3 were aborted and 1 was macerated at hysterotomy. All 7/14 lambs that survived to near term showed scalp healing (Fig 1l). All 7 VSGS remained under the scalp without migration (Fig 1j-1k) (Table 1). Postmortem MRI showed improved hydrocephalus in 4/7 cases (Table 1).

Conclusion: Prenatal placement of VSGS proved feasible in this animal model. The procedure resulted in a 50% fetal loss, which may be due to procedural factors or stress from repeated procedures. Improved hydrocephalus occurred in 57% of survivors. To improve success, future studies will investigate the efficacy and safety of VSGS using less invasive approaches, including fetoscopic placement of VSGS.