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US-12622808-B2 - Cryogenic treatment systems

US12622808B2US 12622808 B2US12622808 B2US 12622808B2US-12622808-B2

Abstract

Methods and apparatus for the treatment of a body cavity or lumen are described where a heated fluid and/or gas may be introduced through a catheter and into treatment area within the body contained between one or more inflatable/expandable members. The catheter may also have optional pressure and temperature sensing elements which may allow for control of the pressure and temperature within the treatment zone and also prevent the pressure from exceeding a pressure of the inflatable/expandable members to thereby contain the treatment area between these inflatable/expandable members. Optionally, a chilled, room temperature, or warmed fluid such as water may then be used to rapidly terminate the treatment session.

Inventors

  • Daniel R. BURNETT
  • Ric COTÉ
  • William W. Malecki
  • Brian M. Neil
  • David Beaulieu
  • Benjamin D. VOILES

Assignees

  • Channel Medsystems, Inc.

Dates

Publication Date
20260512
Application Date
20210505

Claims (20)

  1. 1 . A method of treating tissue in a cavity, comprising: positioning a first valve in a first position of the first valve and a second valve in a second position of the second valve, wherein the first valve is positioned along a pump output pathway and the second valve is positioned along a pump input pathway, wherein the first position of the first valve fluidly couples a liner to a pump and the second position of the second valve fluidly couples an ambient environment to the pump; positioning an elongate probe within an infusion lumen into a body lumen to be treated, wherein the liner encloses the elongate probe and where one or more pressure sensors are in fluid communication with the elongate probe; drawing air through the second valve and into the liner via the pump and the first valve, wherein the air is drawn into the liner according to an algorithm wherein an initial increase in pressure is followed by a controlled increase in pressure more gradual than the initial increase in pressure; detecting, using the one or more pressure sensors, whether a pressure within the liner is above a predetermined pressure threshold; introducing a cryogenic fluid into the liner after the pressure within the liner reaches a predetermined holding pressure; detecting, using the one or more pressure sensors, whether the pressure within the liner is above a maximum pressure threshold; and in accordance with a determination that the pressure within the liner is above the maximum pressure threshold: positioning the first valve in a second position of the first valve and the second valve in a first position of the second valve, wherein the second position of the first valve fluidly couples an ambient environment to the pump and the first position of the second valve fluidly couples the liner to the pump; and evacuating the cryogenic fluid from the liner via the pump and the second valve such that the cryogenic fluid is exhausted via the first valve.
  2. 2 . The method of claim 1 , further comprising performing a check of the one or more pressure sensors by detecting an initial reading from each of the one or more pressure sensors and confirming that each of the initial readings falls within a predetermined range of pressures.
  3. 3 . The method of claim 2 , wherein performing a check of the one or more pressure sensors further comprises comparing each of the initial readings to each other from at least two pressure sensors to determine deviations between the initial readings.
  4. 4 . The method of claim 3 , further comprising comparing deviations between the initial readings between the at least two pressure sensors to perform the check of the one or more pressure sensors.
  5. 5 . The method of claim 1 , wherein the predetermined pressure threshold within the liner is 85 mmHg.
  6. 6 . The method of claim 1 , further comprising detecting for leaks in the liner when the pressure within the liner is below the predetermined holding pressure.
  7. 7 . The method of claim 6 , wherein the predetermined holding pressure within the liner is 40 mmHg or more.
  8. 8 . The method of claim 1 , further comprising detecting a pressure fault after introducing cryogenic fluid into the liner; and stopping introduction of the cryogenic fluid when a pressure fault is detected.
  9. 9 . The method of claim 8 , wherein the pressure fault comprises a detected pressure of 150 mmHg or greater.
  10. 10 . The method of claim 8 , wherein the pressure fault comprises comparing a first pressure reading from a first pressure sensor of the one or more pressure sensors to a second pressure reading from a second pressure sensor of the one or more pressure sensors and determining a deviation between the first pressure reading and the second pressure reading.
  11. 11 . The method of claim 1 , wherein positioning the first valve in the first position of the first valve and the second valve in the second position of the second valve comprises automatically positioning the first valve and the second valve simultaneously or sequentially.
  12. 12 . The method of claim 11 , wherein automatically positioning comprises controlling the first valve and the second valve via a processor.
  13. 13 . The method of claim 1 , wherein drawing air comprises drawing the air via a non-reversible pump.
  14. 14 . The method of claim 1 , wherein the first valve and the second valve each comprises a 3-way solenoid valve.
  15. 15 . The method of claim 1 , wherein drawing air comprises drawing the air from an ambient environment through the second valve.
  16. 16 . The method of claim 1 , wherein, when the cryogenic fluid is introduced into the liner, the first valve is in the second position of the first valve and the second valve is in the second position of the second valve.
  17. 17 . The method of claim 1 , wherein introducing a cryogenic fluid comprises introducing nitrous oxide.
  18. 18 . The method of claim 1 , wherein positioning the first valve in the second position of the first valve and the second valve in the first position of the second valve comprises automatically positioning the first valve and the second valve simultaneously or sequentially.
  19. 19 . The method of claim 1 , wherein evacuating the cryogenic fluid comprises exhausting the cryogenic fluid into an ambient environment.
  20. 20 . The method of claim 1 , wherein the maximum pressure threshold is 150 mmHg or greater.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of U.S. patent application Ser. No. 15/788,041 filed Oct. 19, 2017, which is a continuation of U.S. patent application Ser. No. 14/019,928 filed Sep. 6, 2013 (now U.S. Pat. No. 9,848,933), which is a continuation of U.S. patent application Ser. No. 13/900,916 filed May 23, 2013 (now U.S. Pat. No. 9,486,267), which is a continuation-in-part of U.S. patent application Ser. No. 13/361,779 filed Jan. 30, 2012 (now U.S. Pat. No. 9,283,022), which claims the benefit of priority to U.S. Prov. Pat. App. 61/462,328 filed Feb. 1, 2011 and U.S. Prov. Pat. App. 61/571,123 filed Jun. 22, 2011, each of which is incorporated herein by reference in its entirety. FIELD OF THE INVENTION The present invention relates to medical devices. In particular, the present invention relates to methods and apparatus for therapeutic devices capable of exposing areas of the body to elevated or decreased temperatures, in a highly controlled manner. BACKGROUND OF THE INVENTION In the last few decades, therapeutic intervention within a body cavity or lumen has developed rapidly with respect to delivery of energy via radiofrequency ablation. While successful in several arenas, radiofrequency ablation has several major downsides, including incomplete ablation, frequent lack of visualization during catheter insertion, potential for overlap during treatment (with some areas receiving twice as much energy as other areas), charring of tissues and requirements for frequent debridement, frequent requirements for additional doses of energy after debridement, and potential perforation of the body cavity or lumen due to the rigidity of the RF electrodes. The current state of the art would benefit from minimally invasive devices and methods which deliver thermal energy to a desired area or extract energy from a desired area, in a consistent, controlled manner that does not char or inadvertently freeze certain tissues or create excessive risk of unwanted organ or lumen damage. SUMMARY OF THE INVENTION When bodily tissues are exposed to even slightly elevated temperatures (e.g., 42 degrees C. or greater), focal damage may occur. If the tissues are exposed to temperatures greater than, e.g., 50 degrees C., for an extended period of time, tissue death will occur. The energy delivered by RF can then be excessive while a more controlled treatment can be achieved with heated fluids and/or vapors. Generally, devices for delivering controlled treatment may comprise a source for a heated liquid and/or gas, e.g., hot water/steam, one or more pumps to deliver said hot water/steam, a catheter having one or more lumens defined therethrough and also having one or more ports to deliver or circulate the heated liquid and/or gas, e.g., hot water and/or vapor, to a controlled site in a controlled manner. The catheter may also have optional pressure and temperature sensing elements. The optional pressure and temperature sensing elements may allow the operator to monitor and/or control the pressure and temperature within the treatment zone and also prevent the pressure from becoming too high. The treatment site may be delineated by inflatable or expandable members which are pressurized or expanded to a target pressure to form a seal with the body cavity/lumen. The heated liquid and/or gas may then be delivered to the area contained by the inflatable/expandable members at a pressure that is less than that of the inflatable/expandable members thereby effectively containing the treatment area between these inflatable/expandable members. Optionally, a chilled, room temperature, or warmed fluid such as water may then be used to rapidly terminate the treatment session. The catheter having the inflatable/expandable members and optional pressure or temperature-sensing elements may be fitted within the lumen of an endoscope or other visualization device allowing the therapy to be delivered under direct visualization. In addition to direct visualization, this advance allows the scope to function as an insulator for the treatment catheter, thereby preventing unwanted exposure of body cavities/lumens to the elevated temperatures found in the heated liquid and/or gas coursing within the treatment catheter. Generally, the heated liquid and/or gas may be heated to a temperature of between, e.g., 50 and 100 degrees Celsius. Exposure to these less elevated temperatures may allow for more controlled tissue damage and may obviate issues typically associated with the higher energy forms of treatment. It is understood and known in the art that the lower the temperature, the longer the dwell/treatment time needed. One treatment modality may be to deliver the heated liquid and/or gas at a temperature of, e.g., about 70 degrees C. for 5 minutes. Another modality may be to treat the tissue with the heated liquid and/or gas at a temperature of, e.g., 90 degree C. for 30 secs. Among other features, the system may also include