Cryosurgical apparatus for use in performing ablative surgery; medical devices, namely, cryotherapy and cryosurgical devices, namely, [ surgical and treatment probes, ] catheters, [ endoscopes, ] and control systems for said cryotherapy and cryosurgical devices, namely, apparatuses for controlling the flow of cryogens, [ bleeder and pressure reduction valves for maintaining pressure in cryotherapy and cryosurgical devices and delivery systems, rigid and flexible medical endoscopes, ] and catheters, [ lumen blocking balloons and shields for gastric blocking, nasogastric tubes, suction devices for cryogens removal and endoscopy cameras; ] cryosurgical tools or units used to destroy tissue during surgical procedures, namely, catheters for the introduction of a cryogen to a target tissue; therapy and surgical delivery systems and components thereof for delivering cryogens to a patient, namely, [ surgical and treatment probes, ] catheters [ and endoscopes; ] cryosurgical and cryotherapy device control systems, namely, apparatuses for controlling the flow of cryogens, [ bleeder and pressure reduction valves for maintaining pressure in cryotherapy and cryosurgical devices and delivery systems, rigid and flexible medical endoscopes, ] and catheters, [ lumen blocking balloons and shields for gastric blocking, nasogastric tubes, suction devices for cryogens removal and endoscopy cameras; ] therapy and surgical delivery systems and components thereof, namely, apparatuses for controlling the flow of cryogens, [ bleeder and pressure reduction valves for maintaining pressure in the cryotherapy and cryosurgical devices and delivery systems, rigid and flexible medical endoscopes, ] and catheters [, lumen blocking balloons and shields for gastric blocking, nasogastric tubes, suction devices for cryogens removal, endoscopy cameras ]