A cryosurgical instrument that includes: an external shaft with a cryotip a heat exchanger that cools a portion of the external shaft and the tip when cryogen is received thereby and a flow diverter that receives a flow of cryogen, that splits the received flow of cryogen into two or more split cryogen flows, and that delivers the split cryogen flows to the heat exchanger, the flow diverter including a first passage with one or more inlet ports at an upstream side of the diverter that receive the flow of cryogen and two or more outlet ports at a downstream side of the diverter and in fluid communication with the heat exchanger.