Cryoablation catheter assembly, cryoablation system and method

A cryoablation system, the system comprising:

• a cryoablation catheter assembly, said cryoablation catheter assembly comprising:
• an inlet for receiving an input flow of refrigerant fluid, a cryo-applicator,
• a flow splitter configured to split the input flow into a therapeutic flow portion and a precooling flow portion,
• a precooling arrangement configured to precool the therapeutic flow portion and guide the precooled therapeutic flow portion towards the cryo-applicator,
• wherein the precooling arrangement comprises a heat exchanger configured to apply an adjustable precooling power from the precooling flow portion to the therapeutic flow portion,
• wherein the heat exchanger comprises a boiling chamber, a conduit configured to guide the precooling flow portion from the flow splitter to the boiling chamber, and a heat transfer structure in thermal contact with the boiling chamber and configured to guide the therapeutic flow portion, and
• wherein the conduit comprises a microtube having a flow impedance selected to maintain a ratio between the precooling flow portion and the input flow within a predetermined range,
• a console configured to supply a flow of refrigerant fluid to the inlet of the cryoablation catheter assembly,
• wherein the console comprises a preconditioning unit configured to adjust a specific enthalpy of the refrigerant fluid to a predetermined value, and
• a closing structure is arranged between the conduit and the boiling chamber, the closing structure being configured to adjust a flow cross-section in dependency of temperature.