Interventional MRI - Methods

1357645 - Interventional Cardiovascular Magnetic Resonance Evaluation for Pre-operative Fontan Assessment in Children

Friday, January 27, 2023

12:20 PM – 1:20 PM

Location: Pacific Jewel

Presenting Author(s)

PD

Pezad Doctor, MD

Pediatric Cardiology Fellow
The University of Texas Southwestern Medical Center
Dallas, Texas, United States

Co-Author(s)

Yousef Arar, MD

Pediatric Interventional Cardiology
UT Southwestern
Dallas, Texas, United States
JK

Jamie King, RN

Cardiac Catheterization laboratory Registered Nurse
The University of Texas Southwestern Medical Center, United States
SP

Steven Philip, RT

Cardiac MRI Technologist
Children's Medical Center of Dallas, United States
Tarique Hussain, MD, PhD

Professor, Pediatric Cardiology & Radiology
UT Southwestern Medical Center
Dallas, Texas, United States
RS

Roby Sebastian, MD

Assistant Professor
The University of Texas Southwestern Medical Center
Dallas, Texas, United States
AM

Austin Mercadante, MD

Pediatric Cardiology Fellow
The University of Texas Southwestern Medical Center, United States
Gerald Greil, MD, PhD

Professor of Pediatric Cardiology
UT Southwestern
Dallas, Texas, United States

Primary Author(s)

SR

Suren R. Reddy, MD

Pediatric Interventional Cardiology
University of Texas Southwestern Medical Center
Dallas, Texas, United States

Disclosure(s):

Gerald Greil, MD, PhD: No financial relationships to disclose

Background: Interventional CMR (iCMR) evaluation for comprehensive assessment of single ventricle patients is the standard of care at our institution. The advantage of iCMR is the incremental physiological value of obtaining simultaneous MRI based 3-D anatomical and functional imaging and lymphatic assessment and cardiac catheterization based hemodynamic assessment. Additionally, patients are exposed to lower or no radiation exposure. In this study, we describe the iCMR evaluation protocol (Figure 1) and results for comprehensive pre-Fontan evaluation in single ventricle patients.

Methods:

CMR guided cardiac catheterization exams performed as part of clinically indicated pre-Fontan evaluation between August 2017 and June 2022 were reviewed. iCMR was performed using a passive catheter tracking technique with real-time single shot imaging to visualize the gadolinium-filled (1% dilute) balloon catheter in the Phillips Ingenia 1.5 T system (Philips Healthcare, Netherlands) during cardiac catheterization. An MR-conditional 4 and 6-French Arrow, Balloon Wedge pressure catheter (Teleflex Medical Headquarter, Ireland), and guidewire (angled-tip Emeryglide MRWire, Nano4Imaging, Germany) were used to perform right and left heart catheterization. All patients required general anesthesia during the study. iCMR procedure was considered successful and complete if all predefined MRI imaging and catheter-based pressure and saturation goals were met in the study.

Results:

52 of the 54 (96.3%) patients who consented for the iCMR study completed the study. Of the 2 incomplete cases, one was noted to have bradycardia and hypotension at the beginning of the study and a decision was made to perform MRI followed by catheterization procedure. The other case was aborted due to respiratory complication of plastic bronchitis with complete occlusion of the left mainstem bronchus with bronchial casts noted soon after intubation. Of the 52 completed iCMR studies, 48 (92%) underwent successful and complete iCMR (Table 1). 41/52 (79%) pts were transferred to the cardiac catheterization laboratory (CCL) for X-ray fluoroscopy guided catheter-based interventions and the remaining 11/52 (21%) pts completed the study in MRI suite and were exposed to zero radiation. The following CCL interventions were performed: Aorto-pulmonary collateral coiling (34), Balloon angioplasty (2). The median [IQR] fluoroscopy time was 30 [15.5 – 37.5] minutes and median [IQR] dose product area of radiation was 550 [375.5 – 767.5] µGy.m2. The following T2 W lymphatic imaging was noted: Grade 1 in 7 (13%), grade 2 in 7 (13%), grade 3 in 30 (58%), and grade 4 in 4 (8%), unknown in 4 (8%). Pulmonary vascular resistance (PVR) was calculated in all cases using transpulmonary gradient and branch pulmonary artery flow (by phase contrast).

Conclusion:

ICMR evaluation is a safe and feasible method to perform comprehensive cardiovascular assessment under single anesthesia in children undergoing pre-Fontan evaluation with combined indices including PVR.