Ablation catheter and operation method of same

Abstract

The invention relates to an ablation catheter for treatment of a patient's tissue by delivery of high-voltage pulses comprising a catheter shaft and an ablation portion being arranged at a distal end of the catheter shaft with a plurality of electrodes accommodated along the ablation portion, wherein the ablation portion forms a spiral and comprises a first loop section and a neighboring second loop section, wherein an inner diameter of the first loop section increases towards an inner diameter of the second loop section starting from a first end of the first loop section located opposite the second loop section, wherein the first loop section has a greater stiffness than the second loop section.

What is claimed is: 
     
         1 . An ablation catheter for treatment of a patient's tissue by delivery of high-voltage pulses comprising: a catheter shaft and an ablation portion being arranged at a distal end of the catheter shaft with a plurality of electrodes accommodated along the ablation portion, wherein the ablation portion forms a spiral and comprises a first loop section and a neighboring second loop section, wherein an inner diameter of the first loop section increases towards an inner diameter of the second loop section starting from a first end of the first loop section located opposite the second loop section, wherein the first loop section has a greater stiffness than the second loop section. 
     
     
         2 . The catheter of  claim 1 , wherein the ablation portion is connected to the catheter shaft by a transition joint. 
     
     
         3 . The catheter of  claim 1 , wherein the ablation catheter further comprises a third loop section, which is a neighboring section to the second loop section, wherein an inner diameter of the third loop section increases along the third loop section starting with the end that is closest to the second loop section, wherein the third loop section has a greater stiffness than the second loop section. 
     
     
         4 . The catheter of  claim 1 , wherein the respective stiffness of the first loop section, the second loop section and, if applicable, the third loop section is provided by the form and/or the material of a wire, of the respective loop section. 
     
     
         5 . The catheter of  claim 4 , wherein a first diameter of the wire, of the first loop section is greater than a second diameter of the wire, of the second loop section, for example, the first diameter is between 350 μm and 700 μm and the second diameter is between 200 μm and 349 μm. 
     
     
         6 . The catheter of  claim 4 , wherein the wire of the second loop section comprises at least one indentation and/or the wire of the first loop section and/or, if applicable, the wire of the third loop section comprises at least one elevation at its surface. 
     
     
         7 . The catheter of  claim 1 , wherein a pitch and/or clearance is provided between the first loop section and the second loop section and, if applicable, between the second loop section and the third loop section. 
     
     
         8 . The catheter of  claim 7 , wherein the pitch and/or clearance between the first loop section and the second loop section and, if applicable, the second loop section and the third loop section is between 2 mm and 8 mm, in particular between 4 mm and 6 mm. 
     
     
         9 . The catheter of  claim 1 , wherein the first end of the first loop section is directly attached to the distal end of the catheter shaft or a second end of the second loop section or, if applicable, a second end of the third loop section is directly attached to the distal end of the catheter shaft, wherein the second end of the second loop section and, if applicable, the second end of the third loop section is located opposite the first loop section. 
     
     
         10 . The catheter of  claim 7 , wherein the catheter shaft is generally located at or close to an axis of the spiral form of the ablation portion. 
     
     
         11 . An ablation catheter for treatment of a patient's tissue by delivery of high-voltage pulses comprising: a catheter shaft and an ablation portion being arranged at a distal end of the catheter shaft with a plurality of electrodes accommodated spaced from one another along the ablation portion, wherein the plurality of electrodes comprises at least one first electrode of a first electrode type and at least one second electrode of a second electrode type, wherein a first surface area of the first electrode type is smaller than a second surface area of the second electrode type. 
     
     
         12 . The ablation catheter of  claim 11 , wherein a sequence of accommodation of the electrodes along the ablation portion is such that one first electrode and one second electrode alternate. 
     
     
         13 . The ablation catheter of  claim 11 , wherein the ablation portion forms a three-dimensional spiral, wherein a sequence of accommodation of the electrodes along the ablation portion is such that a plurality of second electrodes is accommodated along a spiral section having a greater inner diameter and that a plurality of first electrodes is accommodated along a spiral section having a smaller inner diameter. 
     
     
         14 . A method to operate an ablation catheter according to  claim 1 , wherein in a first step the catheter shaft is moved distally within the patient's body until the second loop section or, if applicable, the third loop section is brought into contact with tissue at a pre-defined treatment area surrounding a recess, wherein in a second, consecutive step distal movement of the catheter shaft or of a wire connected to the distal end of the ablation portion forces the first loop section to advance into the recess and relatively to the second loop section and, if applicable, to the third loop section. 
     
     
         15 . The method of  claim 14 , wherein in a third step provided after the second step the plurality of electrodes is energized with high-voltage charge-balanced pulsed electric fields which are delivered in a monopolar arrangement or in a bipolar arrangement or in a combination of a monopolar arrangement and a bipolar arrangement.