(114) In-utero Ventriculosubgaleal Shunt Placement in Fetal Lamb Hydrocephalus: Phase II Safety and Outcomes

We evaluated the safety and initial efficacy of intrauterine placement of a ventriculosubgaleal Shunt (VSGS) using a fetal lamb obstructive hydrocephalus model.


Study Design:

Hydrocephalus was induced in fetuses at 91–93 days of gestation by injecting 1–2 mL of BioGlueⓇ into the cisterna magna under ultrasound (US) guidance. Two weeks later, after confirming the hydrocephalus with US, a paramedian laparotomy and hysterotomy were performed under general anesthesia. Next, the fetal head was exposed through the hysterotomy and the distal end of the VSGS was placed in a lateral ventricle, while the proximal end was tunneled subcutaneously (0.5-0.8 mm) and fixed with interrupted silk stitches using a transuterine or hysterotomy-assisted approach. Finally, ewes were euthanized late gestation and fetuses delivered by hysterotomy. Lambs underwent gross inspection and postmortem saline dye testing to assess shunt patency.


Results:

We included eleven fetuses. Nine underwent successful transuterine hydrocephalus induction, while two required a hysterotomy-assisted approach due to difficulty accessing the cisterna magna. At two weeks, one ewe containing two fetuses required euthanasia due to intrauterine demise and severe uterine adhesions. Therefore, a total of nine fetuses underwent hysterotomy-assisted VSGS placement (Table 1). The duration from scalp incision to closure was 5–10 minutes. At cesarean delivery, two out of seven fetuses were demised (22% post-VSGS loss). Skin was fully healed, and the shunt remained in position in all seven survivors. Two of seven shunts (28%) were confirmed patent during post-mortem examination (Figure 1), while the others were occluded by fibrin or debris. No cases exhibited sub scalp cerebrospinal fluid (CSF) accumulation or bulging.


Conclusion:

VSGS placement is technically feasible, with short operative times and high rates of technical success. Post-procedure loss rates were lower than in the first study phase (22% vs 40%). Shunt patency was achieved in only 28% of successfully inserted catheters.