Medical system and approach method

A medical system comprising:

• an elongated catheter;
• an elongated puncture tool configured to be inserted into a lumen of the catheter, the puncture tool including an elongated shaft having a puncture needle at a distal end of the elongated shaft, and wherein the elongated shaft includes a lumen extending from a proximal end of the elongated shaft to the distal end of the elongated shaft and a distal opening communicating with the lumen at the distal end of the elongated shaft;
• and
• a biasing tool that includes a movement portion configured to be movable for applying a biasing force toward a distal direction to a material passing through the lumen and a biasing portion configured to bias the movement portion.

An approach method for approaching a pericardial space from an inside of a heart chamber or an inside of a blood vessel, the method comprising:

• preparing an elongated catheter having flexibility and an elongated puncture tool which is insertable into the catheter, the puncture tool having a puncture needle at a distal end of the puncture tool, and includes a lumen extending from a proximal portion of the puncture tool to a distal portion of the puncture tool and a distal opening communicating with the lumen at the distal portion of the puncture tool;
• inserting the catheter into the blood vessel and delivering the catheter to a puncture position in the heart chamber or the blood vessel from which the puncture tool inserted into the catheter performing a puncture toward the pericardial space;
• at the puncture position, pressing an inner wall of a heart or an inner wall of the blood vessel toward the pericardial space at the distal portion disposed at the distal end of the catheter to make a tenting state;
• making a puncture preparation state by imaging the pressed inner wall of the heart or the pressed inner wall of the blood vessel using an imaging device, biasing a visualization means, which has ultrasonic echogenicity or X-ray radiopacity and is inserted into the lumen, in a direction to push the visualization means out of the lumen from the distal opening of the puncture tool, and restricting movement of the visualization means to an outside from the distal opening;
• and
• in the tenting state and the puncture preparation state, puncturing the inner wall of the heart or the inner wall of the blood vessel with the puncture needle through the lumen of the catheter to release the restriction on the movement of the visualization means, and inserting the biased visualization means into the pericardial space through the distal opening of the puncture tool while imaging by the imaging device.