There is provided a lumen maintenance catheter used for vascular suture, in which an operator can stably grip the catheter to improve the operability, and the entire catheter is prevented from entering a blood vessel. The lumen maintenance catheter for vascular suture includes a shaft having flexibility and a bulging part bulging in a radial direction at a distal end of the shaft, wherein the shaft includes a small diameter part on a distal end side, and a large diameter part larger in diameter than the small diameter part, on a rear end side, the small diameter part and the large diameter part are connected by an inclined part that is inclined so that a diameter of the shaft increases toward the rear end side, and the rigidity of the shaft increases as the diameter increases.
