1. Field of the Invention
The present invention relates generally to treating blood vessels and more particularly to shrinking and/or clogging a blood vessel, such as the great saphenous vein.
2. Description of the Related Art
This invention is related to an apparatus and method for applying energy to shrink or clog blood vessels. The venous system of the lower extremities of human includes the superficial venous system and the deep venous system with veins connecting the two. The superficial venous system includes great saphenous and short saphenous veins.
The arteries carry the blood from the heart while the veins return the blood back to the heart. In the lower extremities, the direction of blood flow in the veins is against the gravitational force. Therefore, the veins of human body have one-way valves to prevent reverse flow of the blood, away from the heart. When these valves fail, the vein will not be able to close completely and the resulting leakage leads to varicose vein and chronic venous insufficiency conditions.
The condition of varicose veins is very obvious to the naked eye due to the swollen and twisted appearance of the veins just under the skin of the legs. Reflux within the great saphenous vein leads to pooling in the visible varicose veins below.
Most of time, there are no symptoms related to the varicose veins other than the visual appearance but when the symptoms worsen, patients can experience pain, blood clots, and skin ulcers.
Current treatment methods for the conditions include surgical stripping of the vein or closing the vein using heat energy or a clogging agent. By closing the vein, blood flow is redirected to other veins including deep veins. This eliminates the symptoms and visual swelling of the superficial veins. By closing the great saphenous vein, the twisted and varicosed branch veins, which are close to the skin, shrink and improve in appearance. Once the diseased vein is closed, other healthy veins take over to carry blood in the leg, re-establishing normal flow.
Surgical stripping of the veins was in practice longer than any other treatment methods but the catheter-based closure procedure is preferred due to the minimally invasive nature and faster recovery time.
Current heat-based closure procedures involve applying laser or RF energy to shrink the veins. The laser procedure has been in use longer than the RF procedure. However, a laser produces much greater heat than radio frequency and therefore requires a higher level of attention to perform. All laser procedures use forward firing laser fiber and require the user to pull the fiber at sufficient rate to insure proper treatment. Over treating at one spot or at an area can cause severe damage to the surrounding tissue.
One apparatus for an RF based heat procedure utilizes electrodes that expand out from the tip of the catheter. Once expanded, the electrodes touch the intima layer of the vein wall to create an impedance loop between the electrodes (bipolar) or between the electrodes and the ground pad (monopolar) to flow RF current. This causes the vein walls to heat up and shrink. With this apparatus the amount of current flow may significantly differ from case to case due to the differences in impedance, thus making this procedure difficult to control. This apparatus also requires the user to move the catheter along the vein to expand the treatment area. Furthermore, this apparatus requires moving the catheter while the electrodes are touching the vein wall with sufficient force to maintain the impedance level. This can cause sudden spikes of current or cold treatment zones if the impedance changes significantly while moving the electrodes.
Another apparatus for an RF procedure uses an enclosed impedance source at the tip of the catheter to produce heat. With this apparatus, since the catheter diameter is smaller than the inner diameter of the vein, the vein has to be squeezed externally to close the gap between the inner wall of the vein and the outer surface of the catheter. In order to achieve this, tumescent fluid is injected around the targeted area of the vein to compress the vein. Uniform compression of the vein is dependent upon the user and the injection technique employed. Although continuous pulling and moving of the catheter is not required like the aforementioned apparatus, the catheter still needs to be pulled back for the length of the treatment zone to expand the treatment area and ensure uniform treatment.
As will be disclosed below the present invention obviates requirements of the above.
In one aspect, the ablating apparatus for use in treating a blood vessel of the present invention includes a proximal balloon subsystem including a proximal balloon positionable to a selected first location within a blood vessel to be ablated. A distal balloon subsystem includes a distal balloon positionable to a selected second location within the blood vessel to be ablated. An ablating subsystem including an ablating element is configured to be positioned between the proximal balloon and the distal balloon within the blood vessel to be ablated. An evacuation port is configured to evacuate fluid between the proximal balloon and the distal balloon.
The ablating element may use any number of modalities that are suitable for ablating a blood vessel. The ablating element may be a heating element. Examples include, but are not limited to, a resistive heater, a radio frequency electrode, a laser heating fiber, and a microwave antenna probe. If it is a resistive heater it may be, for example, a resistive wire heater, semi-conductor material heater or resistive sheath heater. The energy source may be, for example, direct current, alternative current, or radio frequency current. The ablating element may be a cooling element such as a cryosurgical device.
In another aspect, the present invention is a method for treating a blood vessel. A proximal balloon and a distal balloon of an ablating apparatus are positioned to selected spaced locations within a blood vessel to be ablated, the ablating apparatus including an ablating element positioned between the proximal balloon and the distal balloon within the blood vessel. The proximal balloon and the distal balloon are inflated to abut blood vessel walls of the blood vessel at the selected spaced locations. Fluid within the blood vessel between the proximal balloon and distal balloon is evacuated. The ablating element is powered to ablate the blood vessel to be treated, between the proximal balloon and the distal balloon.
The ablating apparatus can be used with an overall multi-functional control system for controlling the overall ablative process including, for example, monitoring the temperature of the ablating device, timing the ablation, and controlling the pressure in the evacuation port(s).
Other objects, advantages, and novel features will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.
Referring now to the drawings and the characters of reference marked thereon,
The ablating element may use any number of modalities that are suitable for ablating a blood vessel. The ablating element may be a heating element. Examples include, but are not limited to, a resistive heater, a radio frequency electrode, a laser heating fiber, and a microwave antenna probe. If it is a resistive heater it may be, for example, a resistive wire heater, semi-conductor material heater or resistive sheath heater. The energy source may be, for example, direct current, alternative current, or radio frequency current. The ablating element may be a cooling element such as a cryosurgical device. Thus, in the various configurations illustrated herein, even though certain elements and subsystems may be referred to as “heating,” this is for the purposes of illustration and other forms of ablation can be utilized.
Referring also now to
Also referring to
A proximal balloon subsystem vacuum seal valve 38 with seal 40 provides evacuation of fluid within the blood vessel between the proximal balloon and the distal balloon.
Referring now also to
Referring now also to
An ablating subsystem vacuum seal valve 58 (e.g. heating subsystem vacuum seal valve) with seal 60 provides evacuation of fluid within the blood vessel between the proximal balloon 14 and the distal balloon 18. The evacuation of such fluid is indicated by the arrows in this figure.
The distal balloon injection tube system 44 is positioned within the ablating element tube system 48 and within the ablating manifold 46. The ablating element tube system 48 is positioned within the proximal balloon injection tube system 36. In this embodiment the proximal manifold 30 includes an evacuation port 24 and the ablating manifold 46 includes an evacuation port 26. However, it is understood that in other embodiments either one or both could have an evacuation port. The evacuation ports should be configured to provide sufficient suction to enable the blood vessel to shrink. The evacuation ports may be connected to an overall ablating system (as will be discussed below). Thus, vacuum pressure for blood and other fluids can be monitored to insure proper shrinkage of the vessel. The ablating system may also monitor temperature and provide energy for ablation. The ablating system is typically configured so that it will not energize the ablation element unless the proper vacuum level has been achieved and will discontinue energy flow if the vacuum level drops below a predetermined threshold. In other embodiments, a user can evacuate blood manually using a syringe while the pressure sensor or gauge, which is attached to the syringe, measures the vacuum level of the evacuation port.
The ablating element 22 may be, for example, any number of suitable heaters. Examples include, but are not limited to, a resistive heater, a radio frequency electrode, a laser heating fiber, and a microwave antenna probe. If it is a resistive heater it may be, for example, a resistive wire heater, semi-conductor material heater or resistive sheath heater. The energy source may be, for example, direct current, alternative current, or radio frequency current. The ablating element may be a cooling element such as a cryosurgical device.
The proximal balloon 14 and/or the distal balloon 18, may be compliant, semi-compliant and non-compliant balloons. They may be formed of, for example, polyamide, Pebax® polyether block amide, polyethylene terephthalate (PET), polyimide, or polyurethane. The expanded diameter size of the proximal balloon 14 and the distal balloon 18 may be in a range of between about 2 mm-10 mm. The length of the distal balloon 18 and the proximal balloon 14 may be in a range between about 5 mm-30 mm. The thickness of the proximal balloon 14 and the distal balloon 18 may be in a range between about 0.005 mm to 0.080 mm.
The proximal balloon injection tube system 36, the distal balloon injection tube system 44, and the ablating element tube system 48 may be formed of biocompatible material, for example polyetheretherketone (PEEK), polythylene, TEFLON® polytetrafluoroethylene, polyamide, polyimide, Hytrel® thermoplastic elastomer, or Pebax® polyether block amide. The wall thickness of these tubes may be in a range of, for example, 0.001 in to 0.025 in.
The distal manifold 42, the proximal manifold 30, and the ablating manifold 46 may be formed of biocompatible material, for example, polyvinyl chloride (PVC), polyethylene, polyetheretherketone (PEEK), polycarbonate, polyetherimide (PEI), polysulfome, polypropylene, polyurethane, polyamide or polyimide.
The present invention is particularly useful for treating varicose veins; however, it can be used for treating a variety of blood vessels and conditions, including, for example, deep vein thrombosis (DVT), peripheral artery disease (PAD), and restenosis.
Referring to
a) inserting the ablating apparatus to an initial position within the blood vessel (
b) inflating the proximal balloon to abut blood vessel walls of the blood vessel (
c) positioning the distal balloon to a distal location of the selected spaced locations (
d) inflating the distal balloon to abut blood vessel walls of the blood vessel (
As shown in
The ablating element is then powered. As shown in
Thus, the present invention eliminates the need for injecting tumescent fluid.
Furthermore, generally in prior systems for treating varicose veins there is a need to press down the skin using a hand. The present invention eliminates this need.
Injection of tumescent fluid typically results in irregular compression of the blood vessel. The present invention provides uniform blood vessel contraction.
Since there is enhanced contact between the blood vessel and the ablating element the ablation time is shortened relative to prior systems. Also, less energy is required.
Referring now to
Referring to
a) inserting the ablating apparatus to an initial position within the blood vessel (
b) inflating the proximal balloon to abut blood vessel walls of the blood vessel (
c) positioning the distal balloon to a distal location of the selected spaced locations (
d) inflating the distal balloon to abut blood vessel walls of the blood vessel (
As shown in
The ablating element is then powered. As shown in
Use of a long heating element with segmented portions obviates the need to move/reposition the apparatus 70 after every ablation. This enables a relatively quick ablation.
Referring now to
Referring now to
Referring now to
Thus, vacuum pressure for blood and other fluids can be monitored to insure proper shrinkage of the vessel. The ablating system is typically configured so that it will not energize the ablation element unless the proper vacuum level has been achieved and will discontinue energy flow if the vacuum level drops below a predetermined threshold.
Referring now to
Referring to
a) inserting the ablating apparatus to an initial position within the blood vessel (
b) inflating the proximal balloon to abut blood vessel walls of the blood vessel (
c) positioning the distal balloon to a distal location of the selected spaced locations (
d) inflating the distal balloon to abut blood vessel walls of the blood vessel (
As shown in
The ablating element is then powered. As shown in
Other embodiments and configurations may be devised without departing from the spirit of the invention and the scope of the appended claims. For example, although the present invention has been described as being utilized with balloons it is understood that alternate proximal and distal devices can be utilized to position the ablating element and evacuate the blood vessel therebetween.
This application claims the benefit of U.S. Provisional Application Ser. No. 62/209,283, filed on Aug. 24, 2015, the entire contents of which are hereby incorporated herein by reference thereto.
Number | Date | Country | |
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62209283 | Aug 2015 | US |