Cryogenic kyphoplasty instrument and methods of use
Inventors
Assignees
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Publication Number
US-9936997-B2
Publication Date
2018-04-10
Expiration Date
Abstract
A surgical instrument includes an outer shaft defining a passageway. An inner shaft is disposed within the passageway and defines a lumen. An expandable structure has a first end coupled to a second end of the outer shaft and a second end coupled to a second end of the inner shaft. The expandable member defines a chamber. A delivery shaft includes a first end positioned within the passageway and a second end positioned within the chamber. The delivery shaft defines a channel configured to deliver a coolant out of an opening in the second end of the delivery shaft and into the chamber to move the expandable structure from an unexpanded configuration to an expanded configuration. A variable exhaust valve is in communication with the passageway and is configured to regulate pressure within the chamber. Systems and methods are disclosed.
Core Innovation
The disclosed kyphoplasty surgical instrument uses an expandable cryo balloon within a vertebral body cavity. An expandable structure forms a chamber, and a coolant delivery shaft introduces pressurized coolant into the chamber to move the expandable structure from an unexpanded configuration to an expanded configuration. A variable exhaust valve regulates pressure within the chamber so the chamber conditions are controlled during expansion.
The instrument includes an outer shaft with a passageway and an inner shaft with a lumen that is slidably disposed within the passageway. Axial movement of the inner shaft positions at least a portion of the expandable structure within the passageway. A pressure monitor in communication with the chamber sends a signal to a coolant source to turn a pump off when pressure within the chamber reaches a selected threshold pressure.
The coolant generates cryogenic cold energy by driving a liquid-to-gas transition under controlled pressure conditions, with the patent describing coolant in a liquid state and examples including liquid nitrous oxide. The system optionally includes a thermocouple disposed in the lumen for temperature feedback and/or temperature-related control of the coolant. Cryogenic cold energy is described as being used to denervate or numb surrounding nerves prior to filling the cavity with bone cement.
Claims Coverage
The partial content provides two independent claims. Both independent claims focus on an expandable cryo balloon kyphoplasty surgical instrument with coaxial outer and inner shafts, a coolant delivery shaft to expand a balloon chamber, and a pressure monitor controlling coolant pumping and a variable exhaust valve based on selected threshold chamber pressure.
Coaxial outer and inner shafts with chamber-positioned expandable structure
An outer shaft extending along a longitudinal axis with an inner surface defining a passageway; an inner shaft disposed within the passageway with an inner surface defining a lumen; an expandable structure having a first end coupled to a second end of the outer shaft and an opposite second end coupled to the second end of the inner shaft, the expandable structure comprising an inner surface defining a chamber; the inner shaft being slidably disposed within the passageway such that moving the inner shaft axially along the longitudinal axis positions at least a portion of the expandable structure within the passageway.
Coolant delivery shaft coupled to the chamber for balloon expansion
A delivery shaft comprising a first end positioned within the passageway and a second end positioned within the chamber, the delivery shaft comprising an inner surface defining a channel configured to deliver a coolant out of an opening in the second end of the delivery shaft and into the chamber to move the expandable structure from an unexpanded configuration to an expanded configuration.
Variable exhaust valve and pressure monitor controlling coolant pumping
A variable exhaust valve in communication with the passageway configured to regulate pressure within the chamber; a pressure monitor comprising a first end positioned in the passageway and a second end positioned in the chamber; and a coolant source in communication with the channel, wherein the pressure monitor is configured to send a signal to the coolant source to turn a pump of the coolant source off when pressure within the chamber reaches a selected threshold pressure.
Single-wall compliant balloon with coaxial inner-shaft aperture and temperature-controlled liquid nitrous oxide
An inner shaft second end comprising an aperture coaxial with the longitudinal axis in communication with the lumen; an expandable structure comprising a single wall balloon made from a compliant material, the balloon having a first end coupled to a second end of the outer shaft and an opposite second end coupled to the second end of the inner shaft with an inner surface defining a chamber; a delivery shaft directly coupled to the inner shaft and configured to deliver coolant into the chamber to expand the balloon; a pressure monitor directly coupled to the inner shaft; a variable exhaust valve in communication with the passageway to regulate pressure within the chamber; a thermocouple disposed in the lumen; and a coolant source comprising a supply of pressurized nitrous oxide in a liquid state and a heat element configured to selectively adjust a temperature of the nitrous oxide, wherein the pressure monitor sends a signal to turn the pump off when pressure within the chamber reaches a selected threshold pressure.
Across the independent claims, the inventive coverage centers on a kyphoplasty instrument architecture with coaxially arranged outer and inner shafts, an expandable balloon chamber positioned by axial movement, coolant delivery into the chamber to expand the balloon, and pressure monitoring that signals coolant pumping shutoff when chamber pressure reaches a selected threshold, together with a variable exhaust valve for chamber pressure regulation. Dependent coverage included in the partial content also emphasizes a thermocouple and a liquid nitrous oxide coolant source with temperature adjustment.
Stated Advantages
Used to denervate or numb surrounding nerves before filling the cavity with bone cement.
Documented Applications
Kyphoplasty use with an expandable cryo balloon inserted into a vertebral body cavity and cryogenic cold energy generation prior to bone cement filling.
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