Surgical system and procedure for treatment of medically refractory atrial fibrillation
The invention provides surgical systems and methods for ablating heart tissue within the interior and/or exterior of the heart. A plurality of probes is provided with each probe configured for introduction into the chest for engaging the heart. Each probe includes an elongated shaft having an elongated ablating surface of a predetermined shape. The elongated shaft and the elongated ablating surface of each probe are configured to ablate a portion of the heart. A sealing device affixed to the heart tissue forms a hemostatic seal between the probe and the penetration in the heart to inhibit blood loss therethrough.
1. A method of ablating tissue, comprising:
providing a tissue ablation probe comprising:
a tubular shaft having a proximal end portion and a distal end portion, the distal end portion including a cryogenic ablation surface, and defining a communication passageway;
a cryogen delivery tube extending through the communication passageway from the proximal end portion of the tubular shaft to the distal end portion of the tubular shaft and including at least one aperture proximate the cryogenic ablation surface,
wherein the cryogen delivery tube and the tubular shaft define therebetween a boiler chamber adjacent the cryogenic ablation surface and an exhaust passageway extending through the communication passageway from the boiler chamber to the proximal end portion of the tubular shaft;
shaping the tubular shaft and the cryogen delivery tube via plastic deformation such that the cryogenic ablation surface conforms to a surface of cardiac tissue to be treated;
introducing the tissue ablation probe into a patient's body;
manipulating the tissue ablation probe such that the cryogenic ablation surface contacts the surface of cardiac tissue to be treated;
delivering a pressurized cryogen via the cryogen delivery tube such that it exits the at least one aperture and expands in the boiler chamber, thereby cooling the cryogenic ablation surface via the Joule-Thompson effect; and
recovering the expanded cryogen via the exhaust passageway.
2. A method according to claim 1 , wherein the step of delivering a pressurized cryogen via the cryogen delivery tube comprises:
delivering a cryogen at a pressure between about 600 psi and about 900 psi; and
permitting the cryogen to expand in the boiler chamber to a pressure between about 50 psi and about 200 psi.
3. A method according to claim 1 , further comprising thawing the cryogenic ablation surface prior to removing the cryogenic ablation surface from the surface of cardiac tissue to be treated.
4. A method according to claim 1 , wherein the step of introducing the tissue ablation probe into a patient's body comprises introducing the tissue ablation device through an intercostal penetration.
5. A method of ablating tissue, comprising:
providing a tissue ablation probe comprising:
an elongate, linear probe body including a proximal end portion, an intermediate portion having a cryogenic ablation surface, and a distal end portion;
wherein the probe body further comprises a malleable section disposed between the proximal end portion and the distal end portion; and
a flexible sheath, wherein the probe body is disposed at least partially within the flexible sheath such that moving the flexible sheath relative to the probe body adjusts an exposed length of the cryogenic ablation surface;
shaping the malleable section of the probe body such that the cryogenic ablation surface will conform to a surface of cardiac tissue to be treated;
placing the cryogenic ablation surface into contact with the surface of cardiac tissue to be treated; and
cooling the cryogenic ablation surface.
6. The method according to claim 5 , wherein the probe body is slidably disposed within the flexible sheath.
7. The method according to claim 5 , wherein there is overlap between the cryogenic ablation surface and the malleable section.
8. The method according to claim 7 , wherein the cryogenic ablation surface and the malleable section are not coextensive.
9. The method according to claim 5 , wherein the step of shaping the malleable section of the probe body comprises plastically deforming the malleable section of the probe body.
10. A method of ablating tissue, comprising:
providing a tissue ablation probe having a proximal end portion and a distal end portion, the distal end portion including a cryogenic ablation region and a malleable region;
shaping the malleable region of the tissue ablation probe such that the cryogenic ablation region conforms to a surface of cardiac tissue to be treated;
introducing the tissue ablation probe into a patient's body;
manipulating the tissue ablation probe such that the cryogenic ablation region contacts the surface of cardiac tissue to be treated; and
cooling the cryogenic ablation region.
11. The method according to claim 10 , wherein there is overlap between the cryogenic ablation region and the malleable region.
12. The method according to claim 11 , wherein the cryogenic ablation region and the malleable region are not coextensive.
13. The method according to claim 10 , further comprising a sheath surrounding at least a portion of the tissue ablation probe, and wherein the sheath is movable relative to the tissue ablation probe such that an exposed area of the cryogenic ablation region is adjustable.
14. The method according to claim 10 , wherein the step of shaping the malleable region of the tissue ablation probe comprises plastically deforming the malleable region of the tissue ablation probe.
15. The method according to claim 10 , wherein the step of cooling the cryogenic ablation region comprises delivering a pressurized cryogen and allowing the pressurized cryogen to expand within the cryogenic ablation region, thereby cooling the cryogenic ablation region via the Joule-Thompson effect.
16. The method according to claim 15 , wherein the pressurized cryogen is delivered at a pressure of between about 600 psi and about 900 psi and allowed to expand to a pressure of between about 50 psi and about 200 psi.