Cryotherapeutic devices for renal neuromodulation and associated systems and methods

Abstract

Cryotherapeutic devices for renal neuromodulation and associated systems and methods are disclosed herein. A cryotherapeutic device configured in accordance with a particular embodiment of the present technology can include an elongated shaft having a distal portion and a supply lumen along at least a portion of the shaft. The shaft can be configured to locate the distal portion intravascularly at a treatment site proximate a renal artery or renal ostium. The supply lumen can be configured to receive a liquid refrigerant. The cryotherapeutic device can further include a cooling assembly at the distal portion of the shaft. The cooling assembly can include an applicator having a distributor in fluid communication with the supply lumen and a balloon configured to deliver cryotherapeutic cooling to nerves proximate the treatment site when the cooling assembly is in a deployed state.

1 . A cryotherapeutic device, comprising:
 an elongated shaft having a distal portion wherein the shaft is configured to locate the distal portion intravascularly at a treatment site in or otherwise proximate a renal artery or renal ostium;   a supply lumen housed within at least a portion of the shaft and configured to transport refrigerant along the shaft to the distal portion, the supply lumen having a terminal opening through which refrigerant can flow from the supply lumen into the distal portion;   a cooling assembly at the distal portion of the shaft, the cooling assembly having a delivery state and a deployed state, and the cooling assembly including—
 an applicator having an expansion chamber wherein the distal portion extends axially through the expansion chamber; and 
 a distributor positioned at a distal end of the cooling assembly, wherein the distributor is in fluid communication with the terminal opening, and wherein the distributor includes a plurality of first orifices radially spaced apart from one another around the shaft and through which refrigerant can flow from the terminal opening into the expansion chamber; 
   an exhaust path extending from the expansion chamber along at least a portion of the shaft, the exhaust path including a plurality of second orifices proximate the first orifices and radially spaced apart from one another around the shaft and through which refrigerant can flow from the expansion chamber; and   an internal barrier configured to seal the shaft at a position intermediate the terminal opening and the plurality of second orifices.   
     
     
         2 . The cryotherapeutic device of  claim 1 , wherein the plurality of first orifices are radially off-set from the plurality of second orifices. 
     
     
         3 . The cryotherapeutic device of  claim 2 , wherein the off-set is one of 90°, 60°, 45° and 30°. 
     
     
         4 . The cryotherapeutic device of  claim 1  further comprising a distal seal at a shaft terminus. 
     
     
         5 . The cryotherapeutic device of  claim 1  further comprising an atraumatic tip at a shaft terminus. 
     
     
         6 . The cryotherapeutic device of  claim 1  further comprising a shaft support at the distal portion. 
     
     
         7 . The cryotherapeutic device of  claim 6 , wherein the shaft support is positioned circumferentially around the shaft in a plane perpendicular to the shaft and circumjacent to at least one of the first orifices and second orifices. 
     
     
         8 . The cryotherapeutic device of  claim 6 , wherein the shaft support includes radiopaque material and wherein at least one of the first and second orifices extends through the radiopaque material. 
     
     
         9 . The cryotherapeutic device of  claim 6 , wherein the shaft support includes an open pitch coil support surrounding a portion of the distal portion, and wherein the portion includes at least one of the first and second orifices. 
     
     
         10 . The cryotherapeutic device of  claim 9 , wherein the first orifices have a first diameter and the second orifices have a second diameter, and wherein the open pitch coil support is a wire having a wire diameter less than the first and second diameters. 
     
     
         11 . The cryotherapeutic device of  claim 1  further comprising a pressure monitoring lumen extending along at least a portion of the shaft and having a distal opening in fluid communication with the expansion chamber, wherein the distal opening is cross-sectionally aligned with at least one of the second orifices. 
     
     
         12 . The cryotherapeutic device of  claim 1  further comprising a temperature monitoring sensor cross-sectionally aligned with at least one of the second orifices. 
     
     
         13 . The cryotherapeutic device of  claim 12 , wherein the temperature monitoring sensor is a thermocouple, and wherein the thermocouple has a distal portion cross-sectionally aligned with at least one of the second orifices and wherein a thermocouple lead extends along at least a portion of the shaft. 
     
     
         14 . The cryotherapeutic device of  claim 1  further comprising a capillary tube having a proximal tube end and distal tube end, the capillary tube positioned at the terminal opening of the supply lumen, wherein the capillary tube is configured to receive refrigerant through the proximal tube end from the terminal opening and release refrigerant through the distal tube end into the distal portion of the shaft. 
     
     
         15 . The cryotherapeutic device of  claim 14 , wherein terminal opening has a terminal diameter and wherein the distal tube end has a tube end diameter less than the terminal diameter. 
     
     
         16 . The cryotherapeutic device of  claim 1 , wherein the distributor has an outer wall defined by a segment of the distal portion of the shaft within the applicator. 
     
     
         17 . A cryotherapeutic device, comprising:
 an elongated shaft having a proximate portion and a distal portion, the distal portion having a first orifice and a second orifice proximate the first orifice, wherein the shaft is configured to locate the distal portion intravascularly at a treatment site;   a supply lumen configured to transport refrigerant along the shaft to the distal portion, the supply lumen having a distal end and an inflow opening at the distal end, the inflow opening intermediate the first orifice and the second orifice;   a cooling assembly at the distal portion of the shaft, the cooling assembly having a delivery state and a deployed state, and the cooling assembly including an applicator, wherein the distal portion extends axially through the applicator, and wherein the applicator is in fluid communication with the first orifice and the second orifice;   an exhaust passage extending from the second orifice along at least a portion of the shaft, the exhaust passage configured to transport exhausted refrigerant away from the cooling assembly; and   a partition located within the shaft between the first orifice and the second orifice and surrounding the supply lumen, the partition configured to seal the shaft between the first and second orifice.   
     
     
         18 . The cryotherapeutic device of  claim 17 , wherein the first orifice includes a plurality of first orifices radially spaced apart from one another around the shaft, and wherein the second orifice includes a plurality of second orifices radially spaced apart from one another around the shaft. 
     
     
         19 . The cryotherapeutic device of  claim 18  wherein the plurality of first orifices are radially off-set from the plurality of second orifices. 
     
     
         20 . The cryotherapeutic device of  claim 17  wherein the partition includes a plug formed by injecting a barrier material around the supply lumen. 
     
     
         21 . The cryotherapeutic device of  claim 17  further comprising a pressure monitoring lumen extending along at least a portion of the shaft and having a distal opening in fluid communication with the applicator, wherein the distal opening is cross-sectionally aligned with the second orifice. 
     
     
         22 . The cryotherapeutic device of  claim 17  further comprising a temperature monitoring sensor cross-sectionally aligned with the second orifice. 
     
     
         23 . The cryotherapeutic device of  claim 22 , wherein the temperature monitoring sensor is a thermocouple, and wherein the thermocouple has a distal portion cross-sectionally aligned with the second orifice and wherein a thermocouple lead extends along at least a portion of the shaft. 
     
     
         24 . The cryotherapeutic device of  claim 17  further comprising a capillary tube, the capillary tube positioned at the distal end of the supply lumen, wherein the capillary tube is configured to receive refrigerant through a first end from the inflow opening and release refrigerant through a second inflow opening at a second end into the distal portion of the shaft. 
     
     
         25 . The cryotherapeutic device of  claim 24 , wherein supply lumen has a lumen diameter and wherein the second end has a second end diameter less than the lumen diameter. 
     
     
         26 . The cryotherapeutic device of  claim 17  further comprising a shaft support at the distal portion. 
     
     
         27 . The cryotherapeutic device of  claim 17  further comprising a distal seal at a shaft terminus. 
     
     
         28 . The cryotherapeutic device of  claim 17  further comprising an atraumatic tip at a shaft terminus. 
     
     
         29 . The cryotherapeutic device of  claim 17 , wherein the applicator includes a balloon. 
     
     
         30 - 89 . (canceled)