Cardiothoracic Surgeon Masahiro Ono, MD, PhD is a UNOS-certified heart transplant surgeon whose expertise extends to mechanical circulatory support (MCS) and the placement of ventricular assist devices (VADs). For patients with advanced heart failure awaiting a heart transplant, or who aren’t eligible for a heart transplant, ventricular assist devices, or VADs, may be an option. VADs are mechanical pumps that circulate blood from the ventricles (lower chambers of the heart) to the rest of the body.