Methods and devices for reducing pressure
11406393 · 2022-08-09
Assignee
Inventors
Cpc classification
A61B2090/064
HUMAN NECESSITIES
A61B17/12172
HUMAN NECESSITIES
International classification
Abstract
The disclosure provides device and related methods that can be used to treat edema by applying pressure to a blood vessel such as a jugular vein to restrict flow therein, creating a local decrease in blood pressure within the jugular vein near an outlet of a lymphatic duct, causing lymph to drain from the interstitium.
Claims
1. A method of draining lymph, the method comprising: restricting flow through a jugular vein of a patient affected by heart failure or edema by applying pressure to a neck of the patient at a spot on the neck proximal to the jugular vein with a medical device for treating edema, the medical device comprising: an extended collar member dimensioned to extend at least partway around the neck, a screw threaded through a portion of the collar member, and a projection provided by a tip of the screw protruding inward from an inner surface of the collar member and positioned to press against the spot on the neck, wherein the method includes twisting a head of the screw when the extended collar member is disposed about the neck of the patient to drive the projection into the neck to restrict flow within the jugular vein, thereby decreasing pressure at an outflow of a lymphatic duct.
2. The method of claim 1, further comprising imaging at least a portion of the jugular vein with a medical imaging instrument and using the imaging while applying the pressure to the spot on the neck.
3. The method of claim 1, further comprising restricting flow through the jugular vein by applying, with the projection, pressure to the jugular vein.
4. The method of claim 3, wherein restricting the flow through the jugular vein creates a local decrease in pressure within the jugular vein near the outlet of a lymphatic duct.
5. The method of claim 1, wherein the extended collar member forms a neck cuff that fastens around the neck.
6. The method of claim 1, wherein the extended collar member includes a C-shaped semi-ring that extends about halfway around the neck.
7. A method of draining lymph, the method comprising: creating, within a jugular vein, a local decrease in pressure near an outlet of a lymphatic duct by applying pressure to a neck of the patient at a spot on the neck proximal to the jugular vein using a medical device for treating edema, wherein the device includes: an extended collar member dimensioned to extend at least partway around the neck, a screw threaded through a portion of the collar member, wherein a tip of the screw provides a projection protruding inward from an inner surface of the collar member, the projection positioned to press against the spot on the neck, wherein the method includes twisting a head of the screw when the collar member is disposed about the neck of the patient to drive the projection into the neck to restrict flow within the jugular vein, thereby causing lymph to drain from interstitium and into a venous system of a patient.
8. The method of claim 7, wherein the extended collar member forms a neck cuff that fastens around the neck.
9. The method of claim 7, wherein the extended collar member includes a C-shaped semi-ring that extends about halfway around the neck.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION
(47) The disclosure provide devices and methods for reducing the pressures within the heart especially during its diastolic phase to provide improved filling pattern of the ventricle and enable the AV valve to open at a later time in the isovolumetric relaxation phase of the heart cycle. This may in turn improve contractility of the heart. Furthermore, reducing the pressures during the diastolic phase, which is about 75% of the cardiac cycle, may reduce the pressures throughout the venous system and thus alleviate the edema formed as a result of the excessively high venous and left ventricular filling pressures present in heart failure patients and in ADHF patients. The reduction of pressures in the venous system will in turn enhance lymphatic return because the outflow pressure in the thoracic and lymphatic ducts will be reduced. The thoracic duct empties into the venous system and in heart failure patients the central venous pressure (CVP) is high and therefore the lymphatic return is not as high as it could be if the CVP was reduced.
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(52) In some embodiments, applying 415 the pressure includes making contact between the spot on the neck and a medical device for treating edema, such as the device 101. The method 401 employs the functionality by which the heart is a suction pump that is constantly trying to preserve cardiac output. As such when the right atrium and ventricle detect a reduction or restriction in the return of blood to the right heart during the diastolic phase, the heart muscle will create more negative pressures in an attempt to compensate and pull in the required blood volume and maintain blood flow. Those phenomena of the heart are not necessarily impeded in heart failure patients but if they are impeded they still exist in a lesser extent. Nearly half of all patients with heart failure have a normal ejection fraction (EF). The prevalence of this syndrome, termed heart failure with preserved ejection fraction (HFpEF), continues to increase in the developed world, likely because of the increasing prevalence of common risk factors, including older age, female sex, hypertension, metabolic syndrome, renal dysfunction and obesity.
(53) In heart failure patients, the systolic function can be impaired, the diastolic volume can be impaired in HFpEF patients but the basic ability of the heart muscle to create these negative pressures during the diastolic phase (if the return of blood to the atria is reduced) can still be functional. As a result of the suction mechanism of the right ventricle the overall venous pressure and central venous pressure (CVP) will be reduced as the venous system is directly connected to the right ventricle and atria during the diastole phase. The reduction of the CVP, when the heart increases its suction forces, can lead to improved medical condition in pathologies such as ADHF, reduced kidney filtration, edema, lymphedema, and lymphatic flow. All those pathologies rely on normal CVP in order to function optimally. For example, the reduced CVP will reduce the pressure at the lymphatic outflow both in the thoracic duct and the lymphatic duct. The method 401 may be useful to enhance the lymphatic return and alleviate edema that accompanies most of ADHF hospitalizations.
(54) The method 401 may also reduce the pressures in the renal vein and in the rest of the venous system and thus alleviate the edema by allowing interstitial fluid to return into the venous system and in the lymph nodes, as well. Reducing the venous pressure in the renal vein can improve renal flow and thus improve renal function. Thus the disclosure provides devices, systems and methods for achieving those benefits, which devices, systems, and methods may be very beneficial for patients.
(55) One way for achieving the suction effect of the heart and reduce its diastolic pressures can be to partially restrict the flow in any of the major veins such as the right or left jugular, right or left subclavian, femoral veins, or the inferior vena cava (IVC). The partial flow restriction can be achieved in several ways including but not limited to intravenous, extra venous, and transcutaneous devices which act to limit fluid flow. In some embodiments, a device is placed in or on a patient, activated and any level of restriction from full to partial restriction is achieved. As a result, the pressures in the venous system will be reduced and ADHF patients can be treated to alleviate the edema via both the lymphatic and venous systems drainage of interstitial edema.
(56) As one example of a device of the disclosure, a transcutaneous device 101 for reducing CVP pressure is provided. The device 101 provides an externally applied compression probe that may be located on the patient's skin directly adjacent to a target vessel such as one of the internal jugular veins (IJVs). The right or left internal jugular veins are commonly accessed using the Seldinger technique on the left or right side of the patient's neck for the placement of central venous catheters. A needle and guidewire are advanced through patient's skin into the jugular vein and then a central venous catheter is advanced over the wire either posteriorly or proximally. Here, the compression probe (e.g., device 101) is applied in contact with the skin on the patient's neck. A portion of the compression probe consists of tip 121 which focally compresses the tissue adjacent to the target vessels (e. g. internal jugular) thereby effecting compression of the target vessel thereby reducing distal flow and pressure.
(57) Since the left and right jugular vein are usually in close proximity to the carotid artery the device compression probe tip could have the form of a small hemi balloon inflated to say 40 mm Hg. Such a balloon would compress and occlude the jugular vein having typical pressure of <30 mm Hg without occluding the carotid (which would be extended by arterial blood pressure running upwards of 70 mm Hg). The compression probe can be made form a biocompatible material for example silicon and the rate of jugular constriction can be regulated by ultrasound visualization of the jugular and a confirmation of the pressure reduction by measuring the baseline and after restriction diameter of the opposite internal jugular. Once the probe compresses as desired the collar is then fixed in place and the restriction is maintained throughout the period of the treatment.
(58) To target such a compression probe, ultrasound could be used in the same manner as for determining the site for a needle penetration for placement of a central line. Alternatively, the subject invention could include an ultrasound array integrated into the device. Such an array would enhance accuracy of device placement and also provide capability to monitor pressure and flow distal to the pressure tip.
(59) The pressure probe may be mounted in something like a collar or harness to keep it in place for a considerable time, and the probe may be advanced carefully by one of several means, (e. g. adjustable screw thread or secondary pressure balloon). The compression probe balloon pressure could be displayed on a pressure gage that could be observed as the probe is advanced until an appropriate pressure was achieved (30-70 mm Hg). Devices of the disclosure may also include an integrated pressure/flow sensor (e.g. via ultrasound) which would allow dynamic closed loop adjustment of the compression probe to achieve the desired flow reduction. For example, the compression probe could be cycled on and off at varying intervals to vary the flow restriction and flow reduction and to further allow periods of normal flow.
(60) In related embodiments, the restriction is achieved by a pressing on the femoral vein, similarly as may be done for the jugular vein. Devices and methods of the disclosure may also be used with intravascular edema catheters such as those disclosed in WO 2015/186003; WO 2015/186005; WO 2016/181217; U.S. Pub. 2017/0197021; and U.S. Pub. 2016/0331378, incorporated by reference.
(61) The following approach may be suitable or preferable for some applications. As an example of an extravascular flow restrictor, a compression device can be advanced through the patient's skin to a site located adjacent the target vessel. The tip of the transcutaneous probe selectively applies pressure to the vessel. In one embodiment, the extravascular probe tip consists of an inflatable balloon.
(62) Another extravascular flow restrictor comprises a compression cuff which is placed around the target vessel. Such a device could be placed surgically, percutaneously, or using minimally invasive techniques. A balloon element in the collar would allow selective compression of the target vessel, much like a blood pressure cuff. For patients that frequently suffer from pulmonary edema, such a device could consist of a long-term implant which can be activated by an implantable controller, much like a pacemaker, to adjust venous pressure as needed or prescribed by a physician.
(63) The following embodiments may be useful for reducing the pressures by applying external forces that restrict the jugular vein flow.
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(65) In the depicted embodiment, the extended collar member 515 includes a C-shaped semi-ring that extends about halfway around the neck. The semi-ring further comprises a first tang 557 fastened at a first end 552 of the semi-ring and extending therefrom. The device 501 includes a first screw 531 threaded through the first tang 557. The projection 537 comprises an elastic pad 539 disposed over an inner tip of the screw. An outer base of the screw comprises wide, grip-able head 561. Twisting the wide head 561 of the screw when the extended collar member is disposed around the neck of the patient drives the elastic pad 539 into the neck to restrict flow within the jugular vein. In the depicted embodiment, the semi-ring further comprises a second tang fastened at a second end of the semi-ring and extending therefrom, the second tang having a second screw threaded therethrough.
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(74) Other mechanisms and embodiments of the disclosure include inflatable balloons.
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(84) In other embodiments, the disclosure provides a device for treating edema in which an extended collar member extends at least partway around a neck of a patient and presses a projection against the neck near a jugular vein and in which the collar member self-fastens or is enclosed in a cuff that self-fastens.
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(96) As an example of an intravenous flow restrictor, a catheter can be inserted via a central line placement technique and advanced a few cm into the vein. A partial restriction can be performed using a balloon that opposes the vein and leaves an internal pathway for the blood.
(97) Another indwelling intravenous apparatus can be a balloon and a shaft with longitudinal openings that can be adjusted relative to an introducer sheath and thus control the flow through the restrictor.
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(99) Device and methods of the disclosure may use other features and configurations. On devices such as the open-sheath device 3401, one or more pressure sensor distally and/or proximally to the balloon 3425 can be used to regulate the pressure in the part of the vein that extends from the balloon to the right atrium. Typically, the pressure range that would be desired to achieve is 0-5 mm Hg but lower pressures down to −5 mm Hg may be favorable. The restriction can be done for long duration of several days to enable edema fluid removal. The restriction can be left indwelling or externally deployed for longer durations of weeks and months and deployed a few hours each day to prevent ADHF episodes from occurring.
(100) Other embodiments are within the scope of the disclosure.
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(112) As shown, P2 is the central venous pressure (CVP) near the heart. The central venous pressure is known to be pulsatile due to heart valves function and respirations. P3 is the pressure within the collapsible tube and P1 is the upstream blood pressure. When P3<P2 the tube collapses and prevents flow.
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(114) As the collapsible tube 4219 has smaller cross section than the vessel 4401, and due to mass conservation, the flow velocity in the collapsible tube 4219 is higher than the flow velocity in the vein 4401. Therefore, due to energy conservation and according to the Bernoulli principle, the pressure inside the collapsible tube P3 is smaller than the upstream pressure P1. For certain diameters of the collapsible tube 4219, the pressure inside the collapsible tube can be within the range of the central venous pulsatile pressure.
(115) When the central venous pressure P2 is higher than P3 the tube collapses and flow is halted.
(116) This in turn causes reduction in the central venous pressure. When the central venous pressure reduces below P3 the flow through the restriction is resumed.
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(119) If the average CVP is higher than P3, the episodes of tube collapse will be longer and thus in turn will generate bigger reduction in the CVP. Such pulsatile restriction can also contribute to elimination of flow stagnation areas and thus reduce the risk of thrombus formation. In various embodiments, the restriction can either be total or partial. In preferred embodiments, the level of restriction is adjusted and pressure monitored until the required CVP is obtained to levels between −5 mm Hg to +5 mm Hg.
(120) The disclosure provides methods and device for the treatment of edema with embodiments disclosed for the application to an outside of a body and invasive embodiments included in the disclosure. In certain preferred embodiments, the disclosure provides devices for treating edema. The devices include an extended collar member dimensioned to extend at least partway around a neck of a patient and a projection protruding inward from an inner surface of the collar member, the projection positioned to press against the neck near a jugular vein, thereby restricting blood flow within the jugular vein. Devices of the disclosure may further include one or more pressure sensing transducers to monitor the CVP and control the restrictions. Devices and methods of the disclosure may be used for reducing venous pressure and right ventricular end diastolic pressure. Preferably, devices and methods of the disclosure are used for reducing the pressure in the outflow of the lymphatic ducts and consequently enhancing lymphatic return in fluid overloaded patients. Devices and methods of the disclosure are beneficial for reducing pressures in the renal veins and improving flow across the kidneys and therefore improving urine output in fluid overloaded patients.
(121) Certain embodiments include systems and methods that combine an internal device with an external device and use the internal device and the external device in combination. External devices include the device 101, the screw-based device 501, the disc-based device 1001, the balloon device 1401, the inflatable collar 1901, the tightening cuff style fastening device 2301, and the limb-cuff device 2701. Internal devices include the deployable stent device 3201, the open-sheath device 3401, the intravascular restriction device 3501, and the collapsible tube device 4201. Thus, certain aspects of the disclosure provide a system or kit for treating edema, wherein the system or kit includes an internal device and an external device. The internal device and the external device may each be, for example, any one of those embodiments disclosed herein. Related aspects provide a method thus uses such a system or kit for the treatment of edema.
INCORPORATION BY REFERENCE
(122) References and citations to other documents, such as patents, patent applications, patent publications, journals, books, papers, web contents, have been made throughout this disclosure. All such documents are hereby incorporated herein by reference in their entirety for all purposes.
EQUIVALENTS
(123) Various modifications of the invention and many further embodiments thereof, in addition to those shown and described herein, will become apparent to those skilled in the art from the full contents of this document, including references to the scientific and patent literature cited herein. The subject matter herein contains important information, exemplification and guidance that can be adapted to the practice of this invention in its various embodiments and equivalents thereof.