Abstract: The present invention relates to a portable, hand held, self-contained cryosurgical probe system. In particular, the present invention relates to an improved portable, hand held cryosurgical probe system having easily changeable probes and cryogen sources wherein the cryogen can be provided in precharged cylinders mountable on the hand held unit and/or supplied from remote sources and which is capable of serving a plurality of probes via a multiprobe adapter. The present invention provides the flexibility of easily changeable probes and cryogen sources in a lightweight hand unit whereby different cryogens may be employed at different stages within a procedure or the cryogens may be mixed to vary the effective freeze capacity of the device.

Abstract: A cryoprobe instrument for endoscopic use has been provided that permits the delivery of liquid or gaseous cryogens in the form of a spray. In an embodiment, the cryoprobe instrument includes an elongated, flexible tube having a fluid passage defined therethrough; a proximal connector portion provided at the proximal end of the tube for coupling the tube to a pressurized source of cryogenic refrigerant; and a nozzle tip mounted to the distal end of the tube. The nozzle tip has an outlet orifice constructed and arranged such that through the Joule-Thompson effect, cryogenic refrigerant exiting through the outlet orifice rapidly and substantially expands and cools.

Abstract: An improved cryosurgical system includes means for cooling the cryoprobe instrument to temperatures below the normal boiling point of liquid nitrogen as well as means for recovering the sub-cooled liquid coolant. A unique cryoprobe instrument of simplified construction uses an active vacuum for thermal insulation. Means are provided for controllably adjusting the length of the freezing zone of the cryoprobe to allow the freezing zone to be adjusted for different sizes and shapes of tumors which may be "observed" before surgery by ultrasound imaging. Multiple, disposable cryoprobe instruments can be individually controlled for both operating temperature and freeze zone length. A preferred refrigeration system for sub-cooling liquid nitrogen refrigerant or other cryogenic liquid refrigerant is based on the principles of evaporative cooling.

Abstract: A cryogenic surgical instrument and method of manufacturing the same are described. The instrument is a cryosurgical probe having concentrically arranged cryogenic fluid supply and return tubes extending through a concentric handle portion into a closed end probe shaft wherein the handle portion and a substantial length of the probe shaft are evacuated to provide a layer of thermal insulation between the cryogenic fluid supply and return tubes and the exterior of the instrument. All the parts of the probe structure are joined by vacuum brazing method carried out in an evacuated furnace. The method involves assembling the probe parts into sub-assemblies which are vacuum brazed at a temperature of at least about 1000.degree. F. and a vacuum of at least about 1.times.10.sup.-3 Torr. The sub-assemblies are then assembled into the final probe assembly which is likewise vacuum brazed.

Abstract: A closed end surgical cryoprobe instrument may have a probe shaft diameter of 3 millimeters or less and can achieve and maintain freezing zone temperatures close to that of the liquid cryogenic refrigerant. Using sub-cooled liquid nitrogen at approximately -208.degree. C. freezing zone temperatures as low as -206.degree. C. can be achieved in under 1 minute. The liquid nitrogen supply tube is provided with a plurality of small vent holes to vent gas formed or present in the refrigerant supply tube to the return refrigerant flow channel. The vent holes also allow small amount of liquid nitrogen to vent into the return flow channel to further reduce the temperature differential between the sub-cooled liquid nitrogen supply and the counter current flowing return refrigerant. Heat transfer is maintained through nucleate boiling. In place of vent holes, narrow slits may be provided in the supply tube. Alternatively, a sintered porous metal supply tube can be used as the vent means.

Abstract: A solution suitable as a hypothermic blood substitute for replacing blood in euthermic subjects during surgery are provided. The blood substitute contains a purge solution and a maintenance solution, the latter of which is useful for organ preservation. The purge solution contains an aqueous solution of electrolytes at physiological concentrations, a macromolecular oncotic agent, a biological pH buffer effective under physiological and hypothermic conditions, a simple sugar, and a substrate for the regeneration of ATP. The maintenance solution contains a second aqueous solution of electrolytes containing potassium ions at a concentration range of from 35 to 45 mM, sodium ions at a concentration range of from 80 to 120 mM, magnesium ions at a concentration range of from 2 to 10 mM, chloride ions at a concentration range of from 15 to 20 mM, and calcium ions at a concentration range of from 0.01 to 0.

Abstract: A biopsy needle insertion guide and method of use with an ultrasound probe in medical procedures to accurately position biopsy needles in internal tissues. The insertion guide comprises a body which is removably mountable on an ultrasound probe and which comprises a clamp affixable about the probe and an elongated adjustment guide extending from the clamp in a direction perpendicular to the probe. A slide block engages the adjustment guide and is slidably adjustable therealong and a biopsy needle holder and guide assembly is carried by the slide block and is adjustably extendable from the slide block in a direction parallel to the probe. A method of use is described wherein the insertion guide is used to accurately place biopsy needles in a human prostate, the needles being then used to accurately place cryoprobes in the prostate for cryogenic surgery of the gland.

Abstract: The present invention is directed to a closed circulation tissue warming apparatus for use during surgery to maintain the temperature of tissues at a desired level and to a method of using the apparatus in prostate surgery particularly during transperineal cryoablation of the prostate gland in human males to maintain the temperature of the urethral tissues and thereby prevent urethral sloughing. It may also have utility where it is desired to lower the temperature of surrounding tissues, such as during laser ablation. The apparatus includes a multi-lumen catheter inserted into the urethra and connected to a fluid warming and circulation control means whereby warmed water is circulated through the lumens at a controlled flow rate and temperature. The concentric lumen structure of the catheter provides improved flow and even temperature maintenance along the length of the catheter and the urethra.

Abstract: A hose designed to facilitate supply and return of cryogenic fluid such as a liquefied gas includes supply and return conduits wrapped in multiple layers of reflective metallized material, which is surrounded by a layer of foam material which is, in turn, surrounded by a protective outer layer such as, for example, a woven cover. The conduits are made of a material such as polytetrafluoroethylene. The inventive hose is lightweight and maintains flexibility for extended periods of time with cryogenic fluid flowing through the conduits.

Abstract: An improved cryosurgical system includes means for cooling the cryoprobe instrument to temperatures below the normal boiling point of liquid nitrogen as well as means for recovering the sub-cooled liquid coolant. A unique cryoprobe instrument of simplified construction uses an active vacuum for thermal insulation. Means are provided for controllably adjusting the length of the freezing zone of the cryoprobe to allow the freezing zone to be adjusted for different sizes and shapes of tumors which may be "observed" before surgery by ultrasound imaging. Multiple, disposable cryoprobe instruments can be individually controlled for both operating temperature and freeze zone length. A preferred refrigeration system for sub-cooling liquid nitrogen refrigerant or other cryogenic liquid refrigerant is based on the principles of evaporative cooling.

Abstract: A closed end surgical cryoprobe instrument with probe shaft diameter of 3 millimeters or less is made to achieve and maintain freezing zone temperatures close to that of the liquid cryogenic refrigerant. Using sub-cooled liquid nitrogen at approximately -208.degree. C. freezing zone temperatures as low as -206.degree. C. can be achieved in under 1 minute. The liquid nitrogen supply tube is provided with a plurality of small vent holes to vent gas formed or present in the refrigerant supply tube to the return refrigerant flow channel. The vent holes also allow small amount of liquid nitrogen to vent into the return flow channel to further reduce the temperature differential between the sub-cooled liquid nitrogen supply and the counter-current flowing return refrigerant.

Abstract: A blood substitute suitable for replacing blood in mammalian subjects when performance of surgical procedures at hypothermic temperatures is described. The blood substitute comprises water, electrolytes at physiological concentration, dextran 40 at a concentration sufficient for the blood substitute to achieve a colloidal suspension having a fluid osmotic pressure essentially equivalent to mammalian plasma, HEPES buffer at a physiological pH, dextrose, magnesium ion at a concentration of about 0.01M and potassium ion at a concentration greater than 10 mEq per liter sufficient to prevent or arrest cardiac fibrillation. In one embodiment the blood substitute is a multi-solution system wherein the solutions comprise differing levels of the above-indicated components and are administered sequentially to completely replace a subjects circulating blood.

Abstract: A blood substitute suitable for replacing blood in mammalian subjects when performance of surgical procedures at hypothermic temperatures is described. The blood substitute comprises water, electrolytes at physiological concentration, dextran 40 at a concentration sufficient for the blood substitute to achieve a colloidal suspension having a fluid osmotic pressure essentially equivalent to mammalian plasma, HEPES buffer at a physiological pH, dextrose, magnesium ion at a concentration of about 0.01M and potassium ion at a concentration greater than 10 mEq per liter sufficient to prevent or arrest cardiac fibrillation. In one embodiment the blood substitute is a multi-solution system wherein the solutions comprise differing levels of the above-indicated componants and are administered sequentially to completely replace a subjects circulating blood.

Abstract: A blood substitute suitable for replacing blood in mammalian subjects when performance of surgical procedures at hypothermic temperatures is described. The blood substitute comprises water, electrolytes at physiological concentration, dextran 40 at a concentration sufficient for the blood substitute to achieve a colloidal suspension having a fluid osmotic pressure essentially equivalent to mammalian plasma, HEPES buffer at a physiological pH, dextrose, magnesium ion at a concentration of about 0.01M and potassium ion at a concentration greater than 10 mEq per liter sufficient to prevent or arrest cardiac fibrillation. In one embodiment the blood substitute is a multi-solution system wherein the solutions comprise differing levels of the above-indicated componants and are administered sequentially to completely replace a subjects circulating blood.