Ifeanyi Chinedozi

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.

(1) Background: Fifty percent of patients supported on veno-arterial extracorporeal membrane oxygenation (VA-ECMO) are concurrently supported with an intra-aortic balloon pump (IABP). Acute brain injury (ABI) is a devastating complication related to ECMO and IABP use. The standard of care for ABI diagnosis requires transport to a head CT (HCT) scanner. Recent data suggest that point-of-care (POC) magnetic resonance imaging (MRI) is safe and may be effective in diagnosing ABI in ECMO patients; however, no data exist in patients supported on ECMO with an IABP. We report pre-clinical safety data and a case series to evaluate the safety and feasibility of POC brain MRI in ECMO patients supported with IABP. (2) Methods: Prior to patient use, ex vivo testing with an IABP catheter within the Swoop^® Portable MRI (0.064 T) System™ was conducted. After IRB approval, clinical testing was performed for the safety and feasibility of early ABI detection. (3) Results: No deflection force was measured with a 7.5 French Maquet Linear IABP within the 0.064 T field. Three adult ECMO patients (average age: 40 years; 67% female) supported with IABP completed four POC brain MRI exams (median exam time: 30 min). Multiple signal abnormalities were detected on the POC brain MRI, corresponding to HCT results. (4) Conclusions: Our preliminary results suggest that adult VA-ECMO patients with IABP support can be safely imaged with low-field POC brain MRI in the intensive care unit, allowing for the early and bedside imaging of patients.