Two-dimensional Speckle Tracking Echocardiography and Fetal Cardiac Performance During Fetoscopic Repair of Myelomeningocele

Objective

No clinical standard exists for intraoperative fetal cardiac monitoring during maternal-fetal surgery for fetal myelomeningocele (fMMC). This pilot study explores the feasibility of using speckle tracking echocardiography (STE)-derived functional measurements to characterize cardiac performance throughout fetoscopic fMMC and compares these measures with other common intraoperative cardiac function parameters.

Methods

Continuous fetal echocardiography was performed during fetoscopic fMMC repair with fetal heart rate assessment every 2 minutes and a 4-chamber cine clip and mitral and tricuspid Doppler inflow patterns captured every 5 minutes. Offline postprocessing was used to measure functional data during fetal surgery including left ventricle (LV) global longitudinal strain (GLS), right ventricle (RV) GLS, LV ejection fraction (EF), and RV fractional area of change (FAC). Interrater agreement was determined for all measurements.

Results

Intraoperative fMMC echocardiograms were successfully obtained and analyzed for twenty patients. LV and RV GLS remained stable with a population average of -25.9±2.6% and -23.1±2.0% respectively during fMMC, and comparable to published normative ranges. Cardiac systolic and diastolic function was preserved at all surgical stages as demonstrated by LV EF, RV FAC, and spectral Doppler measurements. Interrater agreement for the spectral Doppler measurements was high, whereas STE agreement was low.

Conclusion

Fetal cardiac image acquisition for STE analysis was feasible during all stages of fetoscopic fMMC repair. Poor interrater agreement and offline post-processing limit the utility of STE for real-time clinical assessment, yet with experienced operators it could serve as a useful tool for scientific innovation to better understand modifiers of intraoperative fetal cardiac function.