An endovascular shunt implantation system, comprising: a guide member having a distal portion configured for being deployed in an inferior petrosal sinus IPS of a patient; a delivery catheter (304, 1304, 3304, 3304') movably coupled to the guide member, wherein a distal end (1344, 3344) of the delivery catheter (3004, 1304, 3304, 3304') comprises or is otherwise coupled to a tissue penetrating element (1350, 3350), such that the delivery catheter (304, 1304, 3304, 3304') and tissue penetrating element (1350, 3350) are translatable relative to the distal portion of the guide member within the IPS; a guard member at least partially disposed over, and movable relative to, the tissue penetrating element (1350, 3350), the guard member having an open distal end portion including an inner surface feature configured to deflect the tissue penetrating element (1350, 3350) away from the guide member when the tissue penetrating element (1350, 3350) is translated distally relative to the guard or when the guard is withdrawn proximally relative to the tissue penetrating element (1350, 3350); and characterized in that the endovascular shunt implantation system further comprises: a shunt delivery shuttle at least partially positioned within a lumen (305, 3305) of, and movable relative to, the delivery catheter (304, 1304, 3304, 3304'), the shunt delivery shuttle comprising an elongate proximal pusher coupled to a distal shuttle portion configured to collapse around an elongate shunt body to thereby transport the shunt body through the delivery catheter lumen (305, 3305), wherein the distal shuttle portion is adapted to self-expand to release the shunt body when the distal shuttle portion is advanced out of the delivery catheter lumen (305, 3305). a guide member having a distal portion configured for being deployed in an inferior petrosal sinus IPS of a patient; a delivery catheter (304, 1304, 3304, 3304') movably coupled to the guide member, wherein a distal end (1344, 3344) of the delivery catheter (3004, 1304, 3304, 3304') comprises or is otherwise coupled to a tissue penetrating element (1350, 3350), such that the delivery catheter (304, 1304, 3304, 3304') and tissue penetrating element (1350, 3350) are translatable relative to the distal portion of the guide member within the IPS; a guard member at least partially disposed over, and movable relative to, the tissue penetrating element (1350, 3350), the guard member having an open distal end portion including an inner surface feature configured to deflect the tissue penetrating element (1350, 3350) away from the guide member when the tissue penetrating element (1350, 3350) is translated distally relative to the guard or when the guard is withdrawn proximally relative to the tissue penetrating element (1350, 3350); and characterized in that the endovascular shunt implantation system further comprises: a shunt delivery shuttle at least partially positioned within a lumen (305, 3305) of, and movable relative to, the delivery catheter (304, 1304, 3304, 3304'), the shunt delivery shuttle comprising an elongate proximal pusher coupled to a distal shuttle portion configured to collapse around an elongate shunt body to thereby transport the shunt body through the delivery catheter lumen (305, 3305), wherein the distal shuttle portion is adapted to self-expand to release the shunt body when the distal shuttle portion is advanced out of the delivery catheter lumen (305, 3305).