Interventional Cardiovascular Magnetic Resonance in Children Undergoing Pre-Operative Fontan Evaluation: One-Stop...

Interventional cardiovascular magnetic resonance (iCMR) provides cardiovascular magnetic resonance (CMR) and cath-derived hemodynamic assessment under the same anesthesia. In this study, we describe the role of iCMR in children with single-ventricle lesions before Fontan palliation.

iCMR-guided right and left heart catheterization were performed using balanced steady-state free precession (bSSFP) or T1 overlay sequences to visualize the gadolinium-filled balloon-tipped catheter in the Phillips Ingenia 1.5 T system scanner. iCMR procedure was defined as successful if all predefined MRI imaging and catheter-based goals were met within the CMR scanner.

iCMR pre-Fontan evaluations were successfully performed in 56 patients between August 2017 to August 2022. 54 (96%) completed the study without complications. Of the 54, 11 (20%) completed the study in the MRI suite with no radiation exposure. The remaining 43 (80%) were transferred to the cardiac catheterization laboratory, mostly for fluoroscopy-guided catheter-based interventions (n = 37 [69%]). Additionally, we performed T2-weighted lymphatic evaluation in 54 (100%), MRI liver elastography in 16 (30%), selective pulmonary gadolinium angiogram in 20 (37%), and pressure-volume loop analysis in 3 (6%) as relevant. During the same period, 68 pre-Fontan evaluations were performed via the traditional "combined approach" wherein children had an CMR study followed by fluoroscopy-guided cardiac catheterization under the same anesthesia. Higher radiation dose was noted in these children via the "combined approach" versus those iCMR studies that required fluoroscopy after iCMR, despite similar rates of cardiac interventions between the two groups.

In children undergoing pre-Fontan evaluation, iCMR is a safe and feasible method for comprehensive cardiovascular assessment under single anesthesia with reduced/no radiation exposure, fewer anesthetic inductions, and minimal procedure-related complications.