Splanchnic Vein Doppler After LVAD Implantation: A Bedside Tool for Guiding Decongestion and Organ Recovery

BackgroundNoninvasive, physiology-based methods to monitor systemic venous congestion and guide volume management early after durable LVAD implantation are lacking. We investigated whether changes in portal, hepatic, and renal vein Doppler flow patterns correlate with net fluid balance and whether these changes are associated with renal function and right ventricular (RV) performance in this setting. MethodsIn this prospective, proof-of-concept observational study at a national referral center for mechanical circulatory support, we enrolled 20 adult patients undergoing durable LVAD implantation between June 2024 and May 2025. Each patient underwent splanchnic venous Doppler ultrasound (hepatic, portal, and renal veins) and focused echocardiography at two time points: early after ICU admission (T0) and within 7 days (T1), post-implantation. Clinical, biochemical, and device parameters were recorded at each time point. Doppler findings were available to treating physicians and could inform real-time decisions; however, no predefined Doppler-guided protocol was applied. ResultsPatients experienced a significant negative fluid balance (median {Delta}=-6034 mL; IQR:- 8145 to -3476), which was accompanied by consistent improvement in venous Doppler profiles and a significant reduction in VExUS score (p < 0.001). Changes in portal and renal vein Doppler patterns correlated with net fluid balance (rho=0.45, p=0.046 and rho=0.68, p=0.001, respectively). A trend was also observed between VExUS change and fluid balance (rho=0.45, p=0.053). Renal function improved significantly, with an increase in eGFR (p=0.033), and right ventricular function showed parallel recovery: RV systolic velocity (S) increased (p=0.001), RV dilation regressed (p=0.008), and tricuspid regurgitation grade decreased (p=0.001). ConclusionsPoint-of-care Doppler assessment of splanchnic venous flow is feasible early after LVAD implantation and reflects dynamic changes in fluid balance, renal function, and RV performance. These findings suggest that venous Doppler ultrasound may provide a physiologic, bedside method to guide decongestive therapy in this complex population, warranting validation in larger, protocol-driven studies. What Is New?O_LIFirst prospective proof-of-concept study to evaluate hepatic, portal, and renal vein Doppler flow patterns in the early period after durable LVAD implantation. C_LIO_LIDemonstrates that portal and renal vein Doppler changes correlate with net fluid balance and parallel improvements in renal function and right ventricular performance. C_LIO_LIShows that bedside splanchnic Doppler assessment is feasible and captures physiologic changes in systemic venous congestion not reflected by conventional parameters. C_LI Clinical ImplicationsO_LISplanchnic vein Doppler assessment provides a noninvasive, physiology-based method to track systemic venous congestion after LVAD implantation and may yield insights into organ recovery. C_LIO_LIThese data provide a foundation for larger studies to determine whether integrating splanchnic Doppler into ICU monitoring improves post-LVAD outcomes. C_LI