Abstract: A catheter provided with a guidewire catheter lumen having a thin covering that is easily punctured by a guidewire at virtually any desired point along the catheter length. The thin covering may be integral with the catheter shaft, or may be a separate component that covers only the portion of the catheter shaft immediately adjacent the outer portion of the guidewire lumen, or may be a thin tubular construct that surrounds the entire catheter shaft. The covering is preferably relatively translucent, allowing for good visualization of the location of the end of the guidewire to enable puncturing of the covering at the desired location along the length of the catheter shaft. The covering is also preferably tear resistant at puncture sites. The catheter shaft is preferably made of a material having a color that provides good visibility against an operating field, and more preferably is phosphorescent either entirely or in part.