Abstract
Introduction:
Heart transplant (HTx) outcomes continue to improve although organs remain limited. Donor-recipient (DR) size matching is critical in pediatrics. Usually, centers apply a subjective donor weight (wt) range based on recipient chest x-ray. DR wt ratios may vary from 0.7–4.
Hypothesis:
A novel 3D tool can be used to predict ideal donor size.
Methods:
A library of 3D reconstructed normal hearts was created from CT/MRI data. A linear fit of normal heart volume vs. body wt was determined for wts up to 22.5kgs (R
2
=0.983). The linear fit was used to predict donor heart volumes and ideal donor wt. Similarly, pre and post HTx hearts were reconstructed from 3 infant pts undergoing HTx.
Results:
[Table] The library was used to predict ideal donor wt targeting 1:1 DR heart volume ratio. Pt A had cardiomegaly and an ideal DR wt ratio of 3.5, which may be outside a center’s usual range. While all 3 Pts had DR wt ratios > 1, Pt A had a downsized graft while Pt B and C had upsized grafts (based purely on DR heart volumes). 3D reconstructions > 1 week post HTx suggest the downsized graft became larger and upsized grafts smaller.
Conclusion:
3D reconstruction has tremendous potential to improve DR size matching in HTx. As the virtual library grows, the ability to accurately predict DR heart volumes will improve. Further, retrospective analysis of transplant cases, wherein 3D matching was used, will allow us to predict the limits of under and oversizing. Finally, this technique has potential to allow “virtual transplantations” wherein we can model a particular donor (green) into a patient-specific recipient (red) and assess fit along with potential for mismatch related morbidity. [Figure]