PEDS6: Virtual Anatomic Fit Study of PediaFlow Implantable VAD in Infants (4 Kg To 8 Kg)

Abstract

Study: Because of the limited anatomic space available for an implantable VAD in infants, anatomic compatibility in infants is a critical design challenge. Unfortunately, there is limited anatomic data available for infants in the first six months of life. Yet the weight of the child nearly doubles during this period (4 kg to 8 kg for the 50 percentile). Therefore the goals of this research was to create a broad 3D anatomic database for the infant, derived from a limited set of serial CT scans of infants (4 kg – 8 kg) and to conduct a virtual fit study of the PediaFlow PF5 pediatric VAD, including inflow and outflow cannula. Methods: The series of axial images and two orthogonal images of 4 kg and 8 kg infants were imported into commercially available reconstruction software (Mimics) to create a 3-D surface model of the chest cavity. The clipping tool in Mimics was used to perform qualitative validation on two patients to assess the accuracy of the reference models for the database. The tool allowed the superimposition of axial, coronal, and sagittal CT imaging views onto 3D models, as shown in Figure 1. Interpolation of anatomic data from two reference patients resulted in an animation of the growth of the thoracic cavity and internal organs from 4 kg to 8 kg. Results: Figure 2 displays the virtual fitting of the PediaFlow PF5 in 5 intermediate anatomic models interpolated between 4 kg and 8 kg. Based on this analysis, we can appreciate the lower limit of patients for whom the PediaFlow and cannula can be fully implanted. Conclusion: Three-dimensional anatomic data for virtual fit studies in infants is limited. This study produced a scalable 3D model, derived from two reference CT scan data of two patients, that can be used for virtual fit studies, and can also be exported for 3D printing and 4D reconstruction. Figure 1. Qualitative validation was performed on the reconstructed anatomy of a 4-day-old patient infant. Figure 2. Results of virtual fit studies in 5 different anatomic models