Embolization particles can be safely delivered to the left gastric artery of a patient by introducing the distal end of a catheter in the patient's left gastric artery, inflating a balloon located near the distal end of the catheter so that the balloon prevents blood from flowing through the left gastric artery, and injecting a mixture of particles and contrast agent into the proximal end of the catheter so that they flow through the catheter. In addition, a path is provided for blood to flow into the catheter through an opening in the sidewall of the catheter at a position that is proximal to the balloon, and out through the distal end of the catheter. This blood flow helps to carry the particles along to their destination in the distal portion of the left gastric artery. The particles are also prevented from flowing into portions of the patient's artery system that are proximal of the balloon.
