Blood Pressure Optimization During Fetoscopic Repair of Open Spinal Dysraphism: Insights from Advanced Hemodynamic Monitoring

Abstract

Background/Objectives: Fetoscopic repair of open spinal dysraphism (OSD) is a rare intrauterine procedure performed in specialized fetal surgery centers. Conducted under restrictive fluid management and continuous tocolysis, it poses substantial challenges to maternal hemodynamic stability. Blood pressure optimization with vasopressor boluses is often required, yet intraoperative hemodynamic data remain limited. Methods: This prospective observational study was conducted between December 2023 and January 2025 during fetoscopic repair of OSD at Marburg University Hospital, Germany. Maternal hemodynamics were continuously monitored using pulse contour analysis with the Acumen IQ sensor and HemoSphere platform (Edwards Lifesciences, Irvine, CA, USA). To stabilize arterial pressure, cafedrine/theodrenaline (Akrinor, Ratiopharm, Ulm, Germany) was administered as intravenous boluses. Hemodynamic parameters were analyzed immediately before and after each bolus. Fetal heart rate was assessed as a secondary parameter at predefined intraoperative time points when available. Results: A total of 13 patients and 110 vasopressor boluses were analyzed. Reported values reflect median percent changes; parentheses indicate the total range. Following maternal blood pressure optimization, mean arterial pressure increased by 13.7% (5.9-21.6), systemic vascular resistance index by 23.1% (8.3-36.7), and dP/dtmax by 21.7% (6.3-29.9): p < 0.001 for all. Cardiac index and stroke volume index decreased by -6.7% (-11.8 to -0.6), p < 0.001, and -4.3% (-9.8 to 1.8), p = 0.048, respectively. Fetal heart rate remained stable (+0.4% (-0.8 to 1.5); p = 0.470). A total of 38 HPI alerts were followed by hypotension, with a median latency of 120 s (80-235); 73 alerts were not followed by hypotension during the observation period. Conclusions: Intermittent cafedrine/theodrenaline boluses significantly increased arterial pressure, dP/dtmax, and systemic vascular resistance under conditions of fluid restriction and tocolysis-induced vasodilation. Maternal heart rate remained stable, and cardiac output showed only minor reductions. Fetal heart rate was unchanged following maternal blood pressure treatment, indicating no adverse fetal response to C/T within the observed intraoperative period.

Keywords: advanced hemodynamic monitoring; fetal heart rate; fetoscopic surgery; intraoperative hypotension; open spinal dysraphism.

Figure 1

Flow diagram of patient enrolment, exclusion, and analysis.