Proof-of-Concept Monitoring of Cerebral Hemodynamics in a Porcine Extracorporeal Cardiopulmonary Resuscitation Model Using Dual-Mode Laser Speckle and Intrinsic Optical Imaging

Extracorporeal cardiopulmonary resuscitation (ECPR) is increasingly used for refractory cardiac arrest, yet neurologic outcome is often limited by acute brain injury (ABI) secondary to disrupted cerebrovascular autoregulation (CVAR). We established a proof-of-concept porcine model that combines veno-arterial ECMO with dual-mode optical neuromonitoring. After 10 minutes of untreated ventricular fibrillation, ECMO support was initiated, and a cranial window enabled real-time laser speckle contrast imaging (LSCI) of cerebral blood flow (CBF) and intrinsic optical signal (IOS) mapping of cerebral blood volume (CBV). Mean arterial pressure (MAP) was recorded continuously, and vessel-specific hemoglobin-volume index (HVx) was calculated to quantify CVAR. Cortical vessels became pressure-passive—HVx \texorpdfstring{$\geq$}{>=} 0.3, indicating loss of autoregulation—during the initial minutes of reperfusion and again when ECMO pump speed was deliberately reduced to 75\% and 50\% of baseline. The impairment was heterogeneous and reversible, with adjacent vessels showing either intact (HVx \texorpdfstring{$\leq$}{< =} 0) or impaired CVAR in the same epoch. Neither pump flow nor systemic MAP reliably mirrored these microvascular changes: at several time points, CBF rose while pump output and MAP fell, and vice versa. Despite technical challenges (motion artifact, coagulopathy, lack of invasive flow validation), this single-subject study demonstrates the feasibility of simultaneous LSCI and IOS during ECPR.