Feasibility of vesicoamniotic shunt insertion in an inanimate model: comparison of fetoscopic and ultrasound-guided techniques.

OBJECTIVES: To determine the feasibility of fetoscopic vesicoamniotic shunt insertion (F-VASI) in an inanimate model and to compare F-VASI to ultrasound (US)-guided VASI (US-VASI) with respect to accuracy of shunt placement and overall success rate.

METHODS: An inanimate second-trimester fetus with a replaceable bladder balloon was suspended in a pressurized water tank and localized with US. Fetal position was randomized, the operator was blinded and a 5-Fr Harrison Shunt® decompressed the bladder in both groups. Thirty shunt insertions were performed per group.

RESULTS: Procedure time was longer for F-VASI (15.0 vs. 2.8 min, p < 0.05), although it decreased with practice. F-VASI and US-VASI were similar for adequate depth of insertion (27/30 vs. 27/30, p = 1.0), placement within 1 cm of midline (27/30 vs. 25/30, p = 0.42), bladder puncture (28/30 vs. 28/30, p = 1.0), and overall success rate (27/30 vs. 23/30, p = 0.3).

CONCLUSIONS: F-VASI is feasible in an inanimate model. Overall success rate was similar between the groups, although procedure time was longer for F-VASI. Further study is required to determine whether shunt migration is decreased with F-VASI.