Balloon occlusion device having a proximal valve

A medical device for vessel occlusion, the medical device including an elongated body having a distal end portion, a proximal end portion, and a lumen disposed therethrough, an balloon disposed at the distal end portion of the elongated body, the balloon in fluid communication with the lumen. An opening defined at the proximal end portion of the elongated body, the opening being in fluid communication with the balloon via the lumen, and a valve body moveably disposed at the proximal end portion of the elongated body, the valve body movable between a closed position and an open position, the valve body configured to engage a surface of the elongated body, distal to the opening, to seal the opening when the valve body is in the closed position.