multitube catheter and method for making the same are provided . the assembly includes two or more tube fused together to form one catheter tube shaft . each tube has at least one lumen extending longitudinally through the catheter from its distal end to its proximal end . the tubes are fused together by use of heat & amp ; pressure . heat and pressure can be generated by heat sensitive tube slides over a segment of catheter tubes while metallic mandrels are passed through each tube lumen to protect the lumens during fusion . the heat sensitive tube will shrink once heat is applied . the heat sensitive tube will shrink and apply the required pressure over the catheter tubes . continual heating will melt and re - shape the catheter tubes inside the heat sensitive tube while the letter will not be affected due to its high melting temperature . after cooling , the heat sensitive tube is to be removed , the metallic mandrels are pulled back and the tubes forming the united catheter tube . distal end of the united catheter tube can be splited to form split tip , stepped tip or can be tapered tipped . the proximal segment will form catheter extension legs . the pressure applied can also be created by silicon or rubber tube stretched over the catheter tubes , in a mould , by coextrusion , by over molding , through adhesions are other possible methods .