We would like to draw attention to a useful radiological sign indicating that a percutaneous central venous catheter may be in the ascending lumbar vein. In our neonatal unit there have been two confirmed cases where the ascending lumbar vein had inadvertently been cannulated. In both these cases a loop in the line had been noted in the region of the ileo-femoral vein (see figs 1⇓ and 2⇓). This “looping” or bend …