A catheter including a catheter body having a catheter lumen is disclosed. A manifold assembly is coupled with a proximal catheter portion. A manifold lumen extends through the manifold assembly and includes an assembly cavity extending around the proximal catheter portion. A fluid jet loop including fluid jet orfices along a tapered loop guide surface is coupled with a distal catheter portion. The catheter further includes a composite guide having a proximal guide insert and a distal guide. The proximal guide insert is positioned within the assembly cavity and includes a guide insert surface flush with a catheter body interior wall. The distal guide includes a tapered loop guide surface, and an intermediate guide surface of the catheter lumen is flushly engaged with a leading edge of the tapered loop guide surface, the distal guide continuously tapering inwardly and distally along the tapered loop guide surface.