Surgical Planning and Optimization of Patient-Specific Fontan Grafts With Uncertain Post-Operative Boundary Conditions and Anastomosis Displacement

Objective Fontan surgical planning involves designing grafts to perform optimized hemodynamic performance for the patient’s long-term health benefit. The uncertainty of post-operative boundary conditions (BC) and graft anastomisis displacements may significantly affect the optimized graft designs and lead to undesired outcomes, especially for hepatic flow distribution (HFD). We aim to develop a computation framework to automatically optimize patient-specific Fontan grafts with the maximized possibility of keeping the post-operative results within clinical acceptable thresholds. Methods The uncertainties of BC and anastomosis displacements were modeled by using Gaussian distributions according to prior research studies. By parameterizing the Fontan grafts, we built surrogate models of hemodynamic parameters by taking the design parameters and BC as inputs. A two-phased reliability-based robust optimization (RBRO) strategy was developed by combining deterministic optimization (DO) and optimization under uncertainty (OUU) to reduce the computation cost. Results We evaluated the performance of the RBRO framework by comparing it with the DO method on four Fontan patient cases. The results showed that the surgical plans computed from the proposed method yield up to 79.2% improvement on the reliability of HFD than those from the DO method ( p < 0.0001). The mean values of iPL and %WSS satisfied the clinically acceptable thresholds. Conclusion This study demonstrated the effectiveness of our RBRO framework to address uncertainties of BC and anastomosis displacements for Fontan surgical planning. Significance The technique developed in this paper demonstrates a significant improvement in the reliability of predicted post-operative outcomes for Fontan surgical planning. This planning technique is immediately applicable as a building block to enable technology for optimal long-term outcomes for pediatric Fontan patients and can also be used to other pediatric and adult cardiac surgeries.