Vapor ablation treatment of obstructive lung disease

Abstract

A treatment of obstructive lung disease includes aiming a condensable vapor towards the airway wall, causing a band-shaped lesion to grow to a depth into the airway wall. Ablation parameters are set to control the depth of the band-shaped lesion to encompass the epithelial layer and exclude the smooth muscle layer of the airway. A wide variety of configurations of the vapor delivery are described to create ablation patterns in the airways of the patient with particular emphasis on treating chronic bronchitis.

1 . An intraluminal or bronchoscopic method for treating obstructive lung disease comprising:
 determining at least one discrete area along a surface of the airway to ablate to form a lesion;   computing a dose of vapor to form the lesion based on a set of ablation parameters, the set of ablation parameters selected from the group consisting of (a) anatomic, (b) device and controller, and (c) treatment-specific parameters;   advancing a vapor ablation catheter into the airway of a patient lung;   aiming at least one egress port of the vapor ablation catheter at an angle from the main axis directly towards the surface of the airway; and   delivering the vapor from the at least one egress port into the surface of the airway and according to said computed dose of vapor, and wherein the ablation parameters are operable to limit the depth of the lesion such that the underlying tissue architecture remains intact.   
     
     
         2 . The method of  claim 1 , further comprising rotating the at least one egress port during the delivering step to form a band-shaped lesion. 
     
     
         3 . The method of  claim 1 , wherein the vapor ablation catheter comprises a catheter shaft, and the at least one egress port comprises a plurality of egress ports arranged about the circumference of the catheter shaft, such that the vapor is directed radially in multiple directions towards the surface of the airway wall from the catheter shaft. 
     
     
         4 . The method of  claim 1 , wherein the at least one egress port comprises a plurality of egress ports axially spaced from one another at a distance (d). 
     
     
         5 . The method of  claim 1 , wherein the step of delivering comprises pulsing according to a varying duty cycle. 
     
     
         6 . The method of  claim 4 , wherein the distance (d) is equal to or greater than 1 mm. 
     
     
         7 . The method of  claim 1 , further comprising isolating a region of the airway from the at least one egress port. 
     
     
         8 . The method of  claim 7 , wherein the isolating is performed using at least one inflatable member. 
     
     
         9 . The method of  claim 1 , wherein a set of ablation parameters comprises time duration, and the time duration ranges from 3 to 30 seconds. 
     
     
         10 . The method of  claim 9 , further comprising controlling a distance from the egress port to the airway wall, and wherein the distance is in the range of 1 to 5 mm. 
     
     
         11 . The method of  claim 5 , further comprising measuring the depth of the lesion. 
     
     
         12 . The method of  claim 11 , wherein the duty cycle is adjusted based on the measured depth of the lesion. 
     
     
         13 . The method of  claim 12 , wherein the duty cycle commences at a first range, and is adjusted to a second range, and the second range is less than the first range. 
     
     
         14 . The method of  claim 13 , wherein the first range is from 70 to 100%, and the second range is under 50%. 
     
     
         15 . A surgical method for treating obstructive lung disease in a patient comprising:
 advancing a vapor ablation catheter into an airway of a patient lung;   isolating a target section along the airway to ablate;   aiming at least one egress port of the vapor ablation catheter directly towards a surface of an airway wall of the airway within the target section;   emitting vapor from the at least one egress port into the surface of the airway wall causing a thin ablation layer to form extending from the surface of the airway wall to a depth in the airway wall; and   controlling the depth of ablation layer to include the epithelial layer and exclude the smooth muscle layer of the airway wall.   
     
     
         16 . The method of  claim 15 , wherein the isolating is performed using a balloon. 
     
     
         17 . The method of  claim 16 , wherein the at least one egress port comprises a first set of egress ports circumferentially spaced around the shaft of the catheter. 
     
     
         18 . The method of  claim 17 , wherein the catheter comprises a second set of circumferentially disposed egress ports, the second set spaced a distance from the first set wherein the distance is at least 4 mm. 
     
     
         19 . The method of  claim 15 , wherein the controlling step comprises controlling a time duration of ablation, and the time duration ranges from 3 to 30 seconds. 
     
     
         20 . The method of  claim 15 , wherein the controlling step comprises controlling a distance from the egress port to the airway wall, and wherein the distance is in the range of 1 to 5 mm. 
     
     
         21 . The method of  claim 15 , further comprising controlling or setting an ablation control parameter selected from the group consisting of time duration, duty cycle, energy rate, flowrate, temperature, and pressure. 
     
     
         22 . The method of  claim 15 , further comprising controlling or adjusting a distance from the egress port to the surface of the airway wall based on a target depth to be achieved by the emitted vapor. 
     
     
         23 . The method of  claim 15 , further comprising visually monitoring the surface of the airway and computing a real-time hue change as the ablation layer is forming. 
     
     
         24 . The method of  claim 23 , wherein the step of controlling the depth of ablation comprises halting the emitting vapor if the real-time hue change reaches a predetermined threshold hue level change. 
     
     
         25 . A surgical method for treating obstructive lung disease in a lung of a patient, the lung comprising an airway, an inner wall, and an epithelium, the method comprising forming a plurality of non-contiguous lesions by spraying vapor at the epithelium at spaced-apart locations. 
     
     
         26 . The method of  claim 25 , further comprising computing a set of control parameters to limit each lesion to a target depth so as to leave underlying tissue architecture intact. 
     
     
         27 . The method of  claim 26 , wherein the plurality of non-contiguous lesions comprises patches, segments, half rings, or arcuate segments. 
     
     
         28 . The method of  claim 26 , wherein the control parameters are operable to limit the target depth to less than 1 mm.