Method and devices for treating atrial fibrillation by mass ablation

Abstract

Apparatus and method for ablating target tissue including a non-linear area of tissue in the left atrium of a patient. The method can include selecting an ablation apparatus having an ablator with a tissue engagement section, penetrating a chest cavity of the patient, and identifying the target tissue. The method can also include positioning the ablation apparatus adjacent to the target tissue so that the tissue engagement section can transfer ablation energy to the target tissue. The method can further include energizing the tissue engagement section with ablation energy in order to create a footprint on the non-linear area of tissue in the left atrium and to reduce an overall mass of excitable tissue in the left atrium.

Description

RELATED APPLICATIONS [0001] This application claims the benefit of the filing date of U.S. Provisional Patent Application No. 60 / 571,182 filed on May 14, 2004, which is incorporated herein by reference in its entirety.FIELD OF THE INVENTION [0002] The present invention relates to tools and procedures generally and relates more particularly to the use of ablation to reduce the mass of excitable tissue of the left atrium to prevent and treat atrial fibrillation or other medical conditions. BACKGROUND [0003] Focal triggers initiating atrial fibrillation are thought to frequently arise from the pulmonary veins and their ostia. Surgeons have used the technique of modifying the substrate of the heart in these areas to prevent the propagation of the arrhythmia. In some patients with chronic atrial fibrillation, the Cox / MAZE III procedure has been employed. This procedure controls propagation of the depolarization wavefronts in the right and left atria by means of surgical incisions through...

AI Technical Summary

Benefits of technology

[0012] Some embodiments of the invention provide a method of ablating target tissue including a non-linear area of tissue in the left atrium of a patient. The method can include selecting an ablation apparatus having an ablator or ablation member with a tissue engagement section, penetrating a chest cavity of the patient, and identifying the target tissue. The method can also include positioning the ablation apparatus adjacent to the target tissue so that the tissue engagement section can transfer ablation energy to the target tissue. The method can further include energizing the tissue engagement section with ablation energy in order to create a footprint on the non-linear area of tissue in the left atrium and to reduce an overall mass of excitable tissue in the left atrium.

[0013] In some embodiments, an ablation apparatus can include an insertion tool having a proximal end, a distal end, and a lumen. The ablation apparatus can include an ablator or ablation member having a conductor and a tissue engagement portion. The conductor can include a source end extending from the proximal end of the insertion tool and a delivery end coupled to the tissue engagement portion. The ablator can be removably inserted in the lumen. The ablation apparatus can also include an energy source connected to the conductor. The insertion tool can be inserted into a patient so that the distal end is adjacent the target tissue. The conductor can urge the ablator out of the lumen to engage the target tissue. Energy can be conducted from the energy source to the ablator to create a footprint on the target tissue to reduce an overall mass of excitable tissue.

Problems solved by technology

While the Cox / MAZE procedure is successful in treating atrial fibrillation, the procedure is quite complex and is currently practiced by only a few very skilled cardiac surgeons in conjunction with other open-heart procedures.

The procedure also is quite traumatic to the heart, as in essence, the right and left atria are cut into pieces and sewed back together, to define lines of lesion across which the depolarization wavefronts will not propagate.

A power source creates high levels of electrical energy between the two electrodes causing the tissue to heat to a sufficient level to denature proteins within the tissue and cause cell death.

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