Eilers LF, Britt JJ, Weigand J, Penny DJ, Gowda ST, Qureshi AM, Stapleton GE, Khan A, Webb MK, Bansal M.Pediatr Cardiol. 2024 Oct;45(7):1448-1454. doi: 10.1007/s00246-023-03178-x. Epub 2023 May 21.PMID: 37210685
Commentary by:
Dr. Subhrajit Lahiri (Oklahoma City, OK), section editor of Congenital Heart Disease Interventions Journal Watch
Take-home Points:
- Combined Cardiac MRI and Catheterization Streamlines Pre-Fontan Assessment.
- Combined Protocol Reduces Procedure and Fluoroscopy Time.
- Lower Rate of Additional Interventions with Combined Approach.
Authors begin stating the established practice and variation of routine cardiac catheterization or cardiac MRI or both prior to Fontan surgery to risk stratify patients. At Texas Children’s Hospital the standard practice was to obtain only cardiac catheterization followed by new practice of cardiac MRI followed by cardiac catheterization on the same day under same anesthesia. The authors enlist their MRI protocol.
For cardiac catheterization, standard angiograms for patients who did not have cardiac MRI prior to cardiac catheterization included superior vena cava, inferior vena cava, ascending aorta, descending aorta, and pulmonary vein(s). In patients in the combined group, an angiogram was routinely performed in the superior vena cava. An aortic root angiogram was performed at the discretion of the interventional cardiologist. The cath lab at TCH is connected to the MRI suite through a “barn-door” through which the patient can be slid in from MRI suite to cath lab.
There were 37 patients in the combined MRI and cath group and 40 in the cath only group. As expected, patients who underwent combined procedure had prolonged anesthesia time and intubation time. The combined group had significantly less in-lab time, cath procedure time, contrast dose, and fluoroscopy time.
As shown in the table, a significantly higher number of interventions were performed during catheterization in the catheterization-only group. In the combined group, 7 out of 37 procedures (19%) involved at least one intervention, whereas in the catheterization-only group, 19 out of 40 procedures (48%) included an intervention (p = 0.008). The interventional procedures in the combined group consisted of two aortopulmonary collateral occlusions, four veno-venous collateral occlusions, one pulmonary artery angioplasty, and one internal jugular vein angioplasty. The interventional procedures in the catheterization-only group included 11 aortopulmonary collateral occlusions, four venovenous collateral occlusions, one pulmonary artery angioplasty, one main pulmonary artery test occlusion, three coarctation stent angioplasties, and one pulmonary vein stent angioplasty. In this group, aortopulmonary collateral occlusions were performed based on a subjective assessment of high collateral burden observed on angiography. Without objective data from MRI, the decision to occlude aortopulmonary collaterals was dependent on the operator’s judgment. Of note, the Fontan outcomes did not differ between two groups.
| Combined(n = 37) | Catheterization only(n = 40) | P value | |
|---|---|---|---|
| Age (months) | 48 [42–63] | 48 [42–60.2] | .984 |
| Weight (kg) | 15.6[14.3–19.7] | 15.3 [13.7–17.6] | .335 |
| Anesthesia time (min) | 320 [290–352] | 200 [165–255] | < 0.001 |
| Intubation time (min) | 293 [51] | 193 [73] | < 0.001 |
| In-lab time (min) | 156 [125–187] | 194 [160–248] | 0.002 |
| Catheterization procedure time (min) | 70 [51–97] | 114 [79–155] | < 0.001 |
| Contrast dose (mL/kg) | 1.7 [0.8–2.5] | 3.8 [2.7–4.9] | < 0.001 |
| Radiation exposure (cGy x cm2) | 86 [47.5–159] | 114 [80–159] | 0.090 |
| Fluoroscopy time (min) | 20.4 [10–27] | 26 [17–44] | 0.013 |
| Associated intervention (%) | 7 [19] | 19 [48] | 0.008 |
Comments:
Worldwide, there has been a shift toward obtaining cardiac MRI before Fontan surgery in patients with single ventricle physiology. In fact, some studies have recommended MRI alone, without catheterization, before Fontan. However, most centers, including ours, are yet to be convinced that MRI can fully replace catheterization for risk stratifying single ventricle patients.
This study highlights the benefits of MRI prior to catheterization—reducing the number of interventions and shortening catheterization time. A major contributing factor was the assessment of aortopulmonary (AP) collateral burden, which significantly impacts time and resource utilization in pre-Fontan catheterization. However, the downside of this approach is prolonged anesthesia time.
An ideal solution would be an MRI-guided catheterization, utilizing MRI for cine angiograms and AP collateral burden assessment. The challenge lies in safely occluding AP collaterals in an MRI suite with MRI-compatible coils while accurately defining their anatomy to ensure safe closure. Until this becomes feasible, a shorter MRI protocol and rapid transport from the MRI suite to the cath lab could help minimize anesthesia exposure and total procedure duration.
As more centers adopt pre-Fontan cardiac MRI, this process will likely be refined further. Additionally, MRI can sometimes aid in deciding between a biventricular and single ventricle approach in borderline cases.
