Open Access

ARTICLE

Combining Smaller Patch, RV Remodeling and Tissue Regeneration in Pulmonary Valve Replacement Surgery Design May Lead to Better Post-Surgery RV Cardiac Function for Patients with Tetralogy of Fallot

Zhedian Zhou¹, Tal Geva², Rahul H. Rathod², Alexander Tang², Chun Yang³, Kristen L. Billiar⁴, Dalin Tang^1,*,3, Pedro del Nido⁵

1 School of Biological Science & Medical Engineering, Southeast University, Nanjing, 210096, China.
2 Department of Cardiology, Boston Children’s Hospital, Department of Pediatrics, Harvard Medical School, Boston, MA 02115 USA.
3 Mathematical Sciences Department, Worcester Polytechnic Institute, Worcester, MA 01609, USA.
4 Department of Biomedical Engineering, Worcester Polytechnic Institute, MA 01609, USA.
5 Department of Cardiac Surgery, Boston Children’s Hospital, Department of Surgery, Harvard Medical School, Boston, MA 02115 USA

* Corresponding author: Dalin Tang. Email: .

Molecular & Cellular Biomechanics 2018, 15(2), 99-115. https://doi.org/ 10.3970/mcb.2018.00558

Abstract

Patients with repaired Tetralogy of Fallot (ToF), a congenital heart defect which includes a ventricular septal defect and severe right ventricular outflow obstruction, account for the majority of cases with late onset right ventricle (RV) failure. The current surgical approach, which includes pulmonary valve replacement/insertion (PVR), has yielded mixed results. A computational parametric study using 7 patient-specific RV/LV models based on cardiac magnetic resonance (CMR) data as "virtual surgery" was performed to investigate the impact of patch size, RV remodeling and tissue regeneration in PVR surgery design on RV cardiac functions. Two patch sizes, three degrees of scar trimming (RV volume shrinkages: 9%, 17%, 25%) and hypothetical use of regenerated myocardium as replacement of patch and scar were considered in these models. Our preliminary results indicate that each of the three techniques (smaller patch, RV remodeling, and myocardium regeneration) had modest improvement on post-PVR RV ejection fraction (from 1.76%-4% over the conventional PVR procedure) and combination of all three techniques had the best performance (a 4.74% improvement in ejection fraction over the conventional PVR, for the patient studied). Changes in RV stress, strain and curvatures were also observed. However, their linkages to RV ejection fraction were less clear. Further investigations are required to confirm our findings.

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