Preoperative of balloon pulmonary angioplasty in chronic thromboembolic pulmonary hypertension using virtual balloon expansion: a pilot study

Objectives: Chronic thromboembolic pulmonary hypertension (CTEPH) demands precise balloon pulmonary angioplasty (BPA) planning to address unpredictable hemodynamic outcomes. This pilot study explores the potential of virtual simulation to inform this process. Methods: We developed two virtual BPA (vBPA) approaches for patient-specific computational fluid dynamics (CFD) models derived from preoperative computed tomography pulmonary angiography (CTPA) scans of three CTEPH cases featuring right-lung lesion dominant: vBPA1 for morphology-restoring dilation and vBPA2 for rigid homogeneous dilation. We simulated interventions on 28 vascular regions, generating 336 hemodynamic comparisons quantified via Euclidean distance and a composite score integrating multiple spatial metrics. The Euclidean distance value or composite score represents deviation from virtual POST. Results: Our analysis suggested a complex relationship between pulmonary vascular resistance (PVR) and vortex dynamics. The vBPA simulations indicated a temporal decoupling in hemodynamic response, where initial PVR improvement could coincide with an intensification of high-helicity vortices, potentially associated with subsequent hemodynamic rebound as observed in one patient. Preliminary trends hinted at differential performance of the vBPA methods across lesion types. vBPA2 (rigid dilation) showed relatively lower composite scores for web lesions (composite scores: 0.176-0.220 vs. vBPA1: 0.239-0.262), while vBPA1 (morphology-restoring) produced a relatively lower score for the ring-like stenosis (composite score: 0.168 vs. vBPA2: 0.190). Conclusion: This pilot study presents a computational pipeline that bridges anatomical imaging with simulated hemodynamics for personalized BPA planning. The observed trends suggest that lesion morphology may influence the suitability of different virtual planning strategies. This work provides preliminary insights and a methodological foundation for future validation in larger cohorts aimed at enhancing personalized BPA planning for CTEPH.