Virtual Cardiac Surgery Using CFD: Application to Septal Myectomy in Obstructive Hypertrophic Cardiomyopathy

Obstructive hypertrophic cardiomyopathy (HOCM) is characterized by ventricular wall thickening, diastolic dysfunction, and dynamic outflow tract obstruction, all of which strongly influence the vortex dynamics and pressure distribution in the left ventricle (LV). Severe cases of HCM are usually managed through septal myectomy where the surgeon resects the hypertrophic mass. Surgeons currently try to remove as much tissue as possible in order to optimize the post surgical result. However, excessive debulking increases the chance of ventricular septal defects, bundle branch block or complete heart block, and aneurysmal septal thinning. On the other hand, insufficient tissue removal also leads to unsatisfactory outcomes in terms of reduction of outflow tract pressure gradient. Knowing how much muscle to remove and where to remove it from could reduce the likelihood of complications and suboptimal outcomes. In the present study, we employ an immersed boundary solver to model the effect of septal myectomy for ventricles with HOCM and demonstrate the potential of such an approach for surgical planning.