The invention relates to a laser catheter for bypass surgery. The laser catheter comprises: a tubular arrangement comprising a tubular bundle of optical fibres having distal ends defining an emitting surface for emitting laser radiation in the distal direction of the catheter at the distal end of the catheter, a channel extending in axial direction of the catheter and defined by the inside of the tubular arrangement, which channel is connectable to a suction source and a grid element arranged inside the channel at a distance proximally from the emitting surface, which grid extends in transverse direction of the catheter across the channel. The laser catheter further comprises a narrowing arranged inside the channel and, viewed in axial direction of the catheter, between the emitting surface and the grid.
