Abstract:
An apparatus (10) for cryosurgery having the ability to precisely control the rate and degree of freezing of diseased tissue by means of a cryoprobe (10) having a plurality of removable cryotips (26) and a compensating temperature control system operably associated with the cryoprobe and having a temperature sensor (60) and heating coil (42).
Abstract:
A cryoneedle comprises an outer tube having a distal section with a generally central gas supply line placed within the outer tube. The gas supply line supplies a cryogas for forming an iceball on an outer surface of the outer tube over the distal section. The gas supply line terminates in an expansion chamber placed within the distal section. The cryoneedle comprises a heat exchange helix contacting the inner surface of the outer tube. The heat exchange helix has an increasing surface area per unit distance of the distal section such that the iceball has a generally symmetric shape.
Abstract:
A cryosurgical instrument that is selectively positioned in a patient tissue by rotation. The instrument includes: a manipulation section that permits a user to rotate the instrument; a cryogen supply portion; and a positioning section having a sharp tip at an end and a helical configuration, the positioning section configured to receive cryogen and to permit the received cryogen to cool the positioning section. The positioning section urges the cryosurgical instrument deeper into the patient when the instrument is rotated in a first direction, via the manipulation section, and urges the cryosurgical instrument outward when the instrument is rotated in a second direction that is opposite the first, via the manipulation section.
Abstract:
A cryoprobe for use in cryosurgery and other applications includes a rigid outer tube, an inner coolant inlet tube, a short rigid penetrating segment extending distally from the distal end of the outer tube and a helical baffle having a heating element disposed about the outer surface of the inlet tube. The baffle is adapted to produce turbulent fluid flow improving heat transfer and is able to warm target tissue during rapid freezing and thawing cycles.
Abstract:
The threaded cryostat for a cryosurgical probe system includes an outer tube and a hollow elongated threaded element positioned within the outer tube. The threaded element has integral, external threads that extend from on an outer surface thereof. During operation a working fluid is transported in a first direction between a fluid supply line and a distal end of a cryosurgical probe within a first space defined within the threaded element. Working fluid is transported in a second direction between the distal end of the cryosurgical probe and the fluid supply line within a second space defined between the outer tube and the threaded element.
Abstract:
A medical implement that employs a mechanically supported expandable element. In one embodiment, the mechanically supported expandable element is a balloon. In another embodiment, the mechanically supported expandable membrane is a balloon disposed within a cryogenic catheter usable to treat tissue. A variety of illustrative mechanical support schemes are possible.
Abstract:
The invention provides a catheter (10) for ice mapping and ablation and a method of ablation using the catheter (10). The catheter (10) includes a least two lumens (14, 16) for circulating a refrigerating fluid adjacent an ablation device located at the end of a catheter. The refrigerated ablation device is used to chill a localized region of myocardial tissue, thereby permitting the resulting change in electrical activity to be determined. In response to the test results, the ablation device may be used to make a lesion in the myocardial tissue to correct a cardiac arrhythmia. In one embodiment, the ablation device is an electrode (30) which uses radio frequency energy to ablate the myocardial tissue. Alternatively, the ablation device is an electrode (22) adapted for direct current ablation. In another embodiment, the electrode is replaced with an optical fiber (40) in communication with a laser which uses the laser's light energy to ablate tissue. Yet another embodiment is a cryogenic catheter (10), useful for cooling tissue for other applications, for use as a combined separate mapping or ablation device, or for use with the ice mapping and ablation means of the present invention. The embodiments may include provisions for steering the catheter and for stabilizing the ablation device at the proposed lesion site.
Abstract:
A renal denervation apparatus includes a treatment element dimensioned for deployment on or within a renal artery of a patient. The treatment element comprises a predefined pattern arranged to complete at least one revolution of the treatment element. The apparatus includes a treatment source. The treatment source and treatment element are configured to cooperatively facilitate communication of an agent from the treatment source to the pattern arrangement of the treatment element. The treatment element is configured to deliver denervation therapy using the agent via the pattern arrangement to one or more regions of the renal artery adjacent the pattern arrangement, such that at least one complete revolution of the renal artery is subjected to the denervation therapy.
Abstract:
A renal denervation apparatus includes a treatment element dimensioned for deployment on or within a renal artery of a patient. The treatment element comprises a predefined pattern arranged to complete at least one revolution of the treatment element. The apparatus includes a treatment source. The treatment source and treatment element are configured to cooperatively facilitate communication of an agent from the treatment source to the pattern arrangement of the treatment element. The treatment element is configured to deliver denervation therapy using the agent via the pattern arrangement to one or more regions of the renal artery adjacent the pattern arrangement, such that at least one complete revolution of the renal artery is subjected to the denervation therapy.
Abstract:
A system for treating tissue in a patient includes a body having a cooling fluid supply path and a tissue piercing probe in fluid communication with the cooling fluid supply path. The probe extends distally from the body and is insertable into the tissue through the patient's skin. A cooling fluid source is fluidly coupled with the probe such that when cooling is initiated, cooling fluid flows in the probe thereby cooling the probe and any adjacent tissue. A heater element is in thermal engagement with the cooling fluid source and a power source provides power to the heater element thereby heating the cooling fluid. The power source has sufficient power to heat the cooling fluid to at least a desired temperature but has insufficient power to heat the cooling fluid above a critical temperature which results in rupture of the cooling fluid source.