Cryolipolysis devices and methods therefor

Abstract

Described herein are cryolipolysis devices, systems, and methods for facilitating percutaneous access to a target blood vessel by performing cryolipolysis on subcutaneous adipose tissue obscuring the target blood vessel (e.g., a vessel used for hemodialysis treatment). Generally, the devices include a cooling member carrying a coolant that cools a selected portion of adipose tissue overlying the target blood vessel to reduce the selected portion of adipose tissue, thereby forming a depression in the adipose tissue and allowing the target blood vessel closer to the surface of the skin. In some variations, the cooling member is placed subcutaneously to directly cool the selected portion of adipose tissue. In other variations, the cooling member is placed external to the patient to indirectly cool the selected portion of adipose tissue through the skin.

1 . A device for facilitating percutaneous access to a target blood vessel in a patient, comprising:
 a subcutaneous probe to carry a coolant, the probe comprising an adipose tissue interface surface and a treatment segment, wherein the treatment segment defines a delivery lumen extending at least the length of the treatment segment to carry the coolant toward a distal end of the treatment segment and a return lumen to carry the coolant away from the distal end of the treatment segment.   
     
     
         2 . The device of  claim 1 , wherein the treatment segment overlies and is substantially aligned with a treatment portion of the target blood vessel. 
     
     
         3 . The device of  claim 1 , wherein the delivery lumen and the return lumen are in fluid communication with one another at the distal end of the treatment segment. 
     
     
         4 . The device of  claim 3 , wherein at least a portion of the delivery lumen and at least a portion of the return lumen are separated by a porous wall. 
     
     
         5 . The device of  claim 4 , wherein the probe further comprises a valve coupled to the return lumen to control a rate of a phase transformation of the coolant across the porous wall. 
     
     
         6 . The device of  claim 1 , wherein the probe comprises a proximal probe portion directed along a first axis, and wherein the treatment segment is directed along a second axis that is oriented at a nonzero angle to the first axis. 
     
     
         7 . The device of  claim 1 , further comprising a temperature sensor coupled to the treatment segment of the probe that measures at least one of the temperature of the treatment segment and the temperature of the coolant. 
     
     
         8 . A system for facilitating percutaneous access to a target blood vessel in a patient, comprising:
 a cooling device comprising a subcutaneous probe with an adipose tissue interface surface and a treatment segment defining a fluidic channel to carry a coolant; and a cooling subsystem comprising a cooling mechanism and a fluid distributor, wherein the cooling mechanism modifies a temperature of the coolant, and the fluid distributor delivers the coolant from the cooling mechanism at a flow rate into the fluidic channel of the probe.   
     
     
         9 . The system of  claim 8 , wherein the cooling mechanism comprises a closed fluidic system with a heat exchanger. 
     
     
         10 . The system of  claim 8 , wherein the cooling mechanism comprises a coolant reservoir in fluid communication with the fluidic channel. 
     
     
         11 . The system of  claim 8 , further comprising a control subsystem coupled to the cooling subsystem to control at least one of the flow rate and the temperature of the coolant. 
     
     
         12 . The system of  claim 8 , further comprising a guide member to reposition the probe relative to a treatment portion of the target blood vessel.