Occlusion catheter system for full or partial occlusion

An occlusion catheter system for full or partial occlusion of a vessel includes an occlusion balloon. The balloon is positioned in a folded, uninflated configuration around a central shaft, a proximal shaft, and a distal shaft of the occlusion catheter system, having an outer diameter less than seven French. The balloon is constructed of a semi-compliant or non-compliant material and is sized to have a blown diameter between approximately ten percent to sixty percent greater than the inner diameter of the vessel, whereby an outer surface of the balloon comes into full diametric contact with an inner surface of the vessel upon partial inflation of the balloon and folds are formed in the outer surface of the balloon. The folds define flow channels with inner surfaces of the vessel or with portions of the outer surface of the balloon that allow partial blood flow past the balloon.

BACKGROUND OF THE INVENTION

The present invention pertains generally to vascular occlusion catheters and methods of vascular pre-conditioning while controlling occlusion and perfusion during an occlusion procedure. Pre-conditioning is employed to mitigate ischemia before, during and/or after a vascular occlusion procedure, as well as used to reduce or ameliorate the onset of hypertension during or reduce or ameliorate the onset of hypotension after a vascular occlusion procedure. Vascular occlusions may be indicated in either the venous system and/or the arterial system. Endoarterial occlusion is a procedure in which a blood vessel is at least partially occluded in order to restrict blood flow upstream or downstream of the occlusion site for purposes of a vascular procedure or repair. It is known that transient hypertension is a risk factor in arterial occlusion, particularly aortic occlusion. Transient hypertension occurs when the blood pressure upstream of the occlusion site rises to a potentially unsafe level during the time duration of the occlusion. Upon completion of a procedure requiring arterial occlusion, particularly aortic occlusion, care must be taken during the process of reestablishing blood flow to reduce or ameliorate the onset of hypotension. Thus, arterial occlusion carries with it two twin risks, hypertension during the occlusion and hypotension as the occlusion is withdrawn and blood flow restored that must be managed. Partial occlusion of the aorta is also preferred to mitigate the risk of ischemia below the site of the occlusion to limit or eliminate lack of blood flow to organs and tissue below the occlusion location.

In addition to hypotension and hypertension, techniques allowing partial flow of blood and related fluids past the occlusion member may be desirable to provide at least partial blood flow to portions of the patient's body downstream of the occlusion member. At least partial perfusion past the occlusion member can provide the benefits of focusing or directing a majority of blood flow to the brain, heart and lungs or other upstream portions of the patient, but also potentially increasing the amount of time the occlusion member can be implanted in the patient, by providing at least partial blood flow to the patient's organs downstream of the occlusion member, such as to the patient's liver, digestive tract, kidneys and legs.

Referring toFIG.1PA, partial perfusion may be accomplished by reducing the size of an occlusion member or occlusion balloon1that is attached to a catheter2. The occlusion balloon1may, for example, be partially deflated to allow blood to flow between outer surfaces1aof the occlusion balloon1and inner surfaces3aof a vessel3within which the occlusion balloon1is positioned. This, for example, deflation of the occlusion balloon1may cause the occlusion balloon1to lose contact with the inner surface3aof the vessel3, thereby causing movement of the occlusion balloon1and partial vibration between the vessel3and the occlusion balloon1that is undesirable. Such loss of contact with the inner surfaces3aof the vessel3by the occlusion balloon1is represented inFIG.1PA, by a cylindrical channel4defined between the outer surface1aof the occlusion balloon1and the inner surfaces3aof the vessel3. Loss of contact with the inner surface3aof the vessel3by the occlusion balloon1may also result in the occlusion balloon1and attached catheter2being urged downstream in the vessel3, thereby moving the occlusion balloon1out of its preferred placement. It would be desirable to design, develop and implement an occlusion balloon catheter that maintains contact with the vessel3during partial perfusion to reduce or eliminate such vibrations and movement of the occlusion member during partial perfusion.

Temporary aortic occlusion as an operative method to increase proximal or central perfusion to the heart and brain or other major organs in the setting of shock due to major trauma is generally known. Despite potential advantages over thoracotomy with aortic clamping, resuscitative endovascular balloon occlusion of the aorta (“REBOA”) for trauma has not been widely adopted.

Many attempts have been made at developing technologies to control non-compressible abdominal hemorrhage. For example, non-occlusive, abdominal tamponade procedures have been developed to address the problem of non-compressible hemorrhage, such as introducing an expandable, biocompatible foam into the abdominal cavity to apply pressure to the abdominal organs and vasculature. Pharmacological efforts have also been developed to address the problem of non-compressible hemorrhage. Conventional REBOA procedures are typically performed in an operating room and with the aid of fluoroscopy or other imaging.

Devices that automate inflation and deflation of a balloon are generally known. Intra-aortic balloon counterpulsation catheters for blood pressure augmentation coordinated with electrocardiography signals are also known. Over-inflation safety devices are also known, such as a pressure-relief valve coupled to an inflation lumen that opens when pressure within the inflation lumen exceeds a threshold pressure, but relative pressure within the occlusion balloon is necessary to maintain occlusion of the blood vessel.

It would be desirable to design, develop and implement a system that intermittently and automatically releases an occlusion balloon or member by releasing apposition of the occlusion balloon or member against the vascular wall and allowing perfusion past the occlusion balloon or member in response to a physiological parameter, then re-establishing occlusion in response to potential changes in the physiological parameter, either during a vascular repair procedure to control hypertension or post-repair procedure to control hypotension. It would also be desirable to design, develop and implement a system that allows perfusion past the occlusion balloon or member while maintaining engagement between the occlusion balloon or member and the walls of the vasculature, preferably an artery and more preferably the aorta, to prevent vibration, movement, sliding or shifting of the occlusion balloon or member as blood flows past the occlusion balloon. In addition, it is desirable to design, develop and implement an occlusion balloon that permits relatively fine control of a pressure ratio between proximal and distal sides of the occlusion balloon and, therefore, relatively fine control of blood flow across the occlusion balloon through the vessel. The preferred embodiments of the present invention address certain of these limitations of the prior art occlusion systems.

In addition, it is desirable to design, develop and implement an occlusion balloon that permits relatively fine control of a pressure ratio between proximal and distal sides of the occlusion balloon and, therefore, relatively fine control of blood flow across the occlusion balloon through the vessel. Existing occlusion balloons are difficult to modulate pressure drop across the balloon and modulation can result in movement of the balloon under blood pressure in the balloon. A relatively small change in balloon volume or internal pressure often results in drastic changes in blood pressure between proximal and distal sides of the occlusion balloon, resulting in full occlusion or a relatively high rate of volumetric blood flow across the balloon. It is desirable to design, develop and deploy an occlusion system that is less sensitive to slight pressure changes in the occlusion balloon and provides a more gradual change in blood flow past the occlusion balloon. It is also desired to create catheters with occlusion members that perform both partial and full occlusion. This would allow more gradual transitions between full and no occlusion and also provide surgeons more time to prevent fatal loss of blood in patients. The preferred present invention addresses these shortcomings of prior art occlusion balloons.

A majority of catheters with balloons attached thereto or integrated therewith are bonded together using a lap or overlap weld, wherein the material of the balloon overlaps an end or portion of the catheter. The overlapped portions are then welded or otherwise bonded together to secure the balloon to the catheter. This lap weld causes the profile of the catheter to be greatest at the lap weld because of the overlap of material in this area of the catheter system. Any increase in the size or diameter of the catheter shaft results in an increase in size or counterpart dimension of an introducer sheath through which the catheter is introduced into the patient's body. Alternatively, the catheter shaft may be necked or have a reduced diameter portion at its end where the overlap weld is located in attempts to maintain the overall diameter of the catheter system at the lap weld. This necking of the catheter shaft, however, reduces the flow of inflation medium into and out of the balloon through a reduced diameter internal catheter shaft lumen at the necking area, which is undesirable. In addition, the thickness of the catheter shaft and balloon material may only be reduced to dimensions that allow the catheter and balloon to support the pressures expected within the catheter and the balloon, so that reducing the thickness of the catheter or balloon material is limited by these structural performance parameters. It would be desirable to design, construct and implement a balloon catheter system that minimizes the thickness of the catheter shaft in the weld or connection area with the balloon, while maintaining the size of the internal lumen that extends through this area of the catheter.

BRIEF SUMMARY OF THE INVENTION

Non-compliant or semi-compliant balloons may have certain advantages in REBOA procedures, such as ease of use, because the non-compliant or semi-compliant nature of the balloon causes the internal balloon pressure to increase dramatically once slack in the folds of the non-compliant or semi-compliant balloon is overcome during inflation. Compliant balloons may also be preferred for use in certain REBOA procedures, such as partial occlusion of a vessel where an oversized balloon is inserted into the vessel.

The preferred catheter systems described herein perform partial and full occlusion of a patient's vessel, preferably a large vessel such as various locations in the patient's aorta, including the descending thoracic aorta and the abdominal aorta. A variety of compliant, semi-compliant and non-compliant balloons may be utilized with the preferred occlusion catheter systems to occlude or partially occlude relatively large vessels in the patient's circulatory system. The preferred compliant, semi-compliant and non-compliant balloons preferably perform well during smooth control tests, preferably exhibiting the ability to gradually transition pressure in the vessel between full and no occlusion, such that transition between full and partial occlusion of the vessel is readily controllable to avoid quick or immediate transitions between full occlusion and virtually no occlusion in the vessel.

Certain non-compliant or semi-compliant balloons were relatively easy to use because of the non-compliant or semi-compliant nature of the balloon, which caused the internal balloon pressure to increase dramatically once the “slack” was taken out of the balloon during inflation. While the non-compliant or semi-compliant balloons were effective for performing full occlusion in the tubes or virtual vessels up to, but not exceeding, their blown diameter, these non-compliant balloons generally cannot occlude tubes larger than their blown diameter or at least somewhat larger than their blown diameter, because the non-compliant balloons do not stretch significantly in the radial direction to come into facing engagement with a full diametric slice or portion of the internal walls of the vessel.

As a preferred example of testing a non-compliant or semi-compliant balloon with the preferred occlusion catheter systems, a non-compliant or semi-compliant balloon with a blown diameter of twenty millimeters (20 mm) and a blown length of twenty millimeters (20 mm) was able to partially occlude a simulated vessel comprised of a tube having a fifteen and one-half millimeter (15.5 mm) inner diameter. In contrast, the same twenty millimeter (20 mm) non-compliant or semi-compliant balloon had a limited ability to gradually transition between partial and full occlusion in a simulated vessel comprised of a tube having a nineteen millimeter (19 mm) inner diameter. As the non-compliant or semi-compliant balloon is inflated, the folds of the twenty millimeter (20 mm) balloon in in the fifteen and one-half millimeter (15.5 mm) tube or simulated vessel defines flow channels with the inner surfaces of the tube or vessel that permit some flow to go past the balloon, even when the outer surface of the balloon is touching the wall of the tube or simulated vessel. In contrast, in the nineteen millimeter (19 mm) tube or simulated vessel, there are very few flow channels created by the folds in the balloon because nearly all of the folds are expanded at this greater diameter, so partial occlusion of the tube or simulated vessel is limited. The twenty millimeter (20 mm) diameter non-compliant or semi-compliant balloon also does not substantially occlude a tube or simulated vessel larger than approximately twenty millimeters (20 mm). The twenty millimeter (20 mm) non-compliant or semi-compliant balloon, accordingly, is not preferred for REBOA procedures when the patient's vessel has an inner diameter in the range of twenty to thirty or more millimeters (20-30+ mm).

In the above-described preferred catheter system example, the occlusion balloon is constructed of a low-compliance, semi-compliant or non-compliant polyethylene terephthalate (“PET”) balloon, but is not so limited. The occlusion balloon may also be constructed of a nylon, urethane, polyether block amide (“PEBA”) or PEBAX material or other similar materials. When the example catheter system is used in vessels or sample vessels smaller in diameter than the blown diameter, the blood vessel or sample vessel is the only material pushing back radially when the balloon inflates. The blood vessel can tolerate some stretching but too much can rupture or cause a dissection. The user preferably stops inflating before this pressure gets too high or a safety feature is incorporated into the catheter system to prevent over-inflation of the occlusion balloon, such as a pop-off or pressure release valve.

In a preferred embodiment, a relatively large diameter, such as a blown diameter of approximately twenty-five to thirty-five millimeters (˜25-35 mm), non-compliant or semi-compliant balloon is mounted near the distal end of the catheter system. A pressure-relief or pop-off valve is mounted at the catheter hub in line or in fluid communication with the balloon inflation lumen at a location of the catheter shaft, hub, extension line, stopcock or proximal to the stopcock of the catheter system to prevent the balloon from overinflating.

The relatively large diameter, non-compliant or semi-compliant balloon, such as, but not limited to, having a blown diameter of approximately twenty-five to thirty-five millimeters (˜25-35 mm), would have folds in almost all aortas. Greater than ninety-five percent of normal aortas have a diameter of twenty-five millimeters (25 mm) or smaller, so the relatively large diameter balloon would have folds when encountering the inner walls of the aorta during inflation or before full inflation. Accordingly, the relatively large non-compliant or semi-compliant balloon incorporated into the system or a non-compliant or semi-compliant balloon that is configured to have a blown diameter of approximately ten to sixty percent (10-60%) greater than an inner diameter of the associated vessel is functional for partially occluding the vessels, particularly for partial occlusion utilizing folds in the partially inflated balloon to create flow channels with the inner surface of the vessel. The non-compliant or semi-compliant, twenty-five to thirty-five millimeter (˜25-35 mm) occlusion balloon, specifically is generally effective for a majority of aortas. The pressure relief valve preferably prevents the user from overinflating the balloon, which could cause aortic rupture/dissection or balloon rupture, but still allow all aortas, generally regardless of size, to be occluded. The preferred catheter system also include a P-tip, hypotube/wire positioned centrally within the catheter system, marks on the outer shaft for placement of the occlusion balloon in a preferred zone of the aorta, no guidewires, and maker bands for visualization of the placement of the balloon.

In a preferred embodiment, the occlusion catheter system is configured for full or partial occlusion of a vessel having a vessel diameter. The occlusion catheter system includes a proximal catheter shaft having a proximal lumen and a hypotube positioned partially within the proximal lumen and spaced from the proximal catheter shaft. The hypotube may also be described as a central shaft. The central shaft may have an internal lumen or may be substantially solid between its proximal and distal ends with both configurations of the central shaft providing strength and stiffness to the preferred catheter for insertion into the patient's vessel. The catheter system also includes a distal catheter shaft attached to a distal end of the hypotube and an occlusion balloon connected at a proximal end to the proximal catheter shaft and at a distal end to the distal catheter shaft. The occlusion balloon has a blown diameter greater than the vessel diameter. The occlusion balloon is configured to define flow channels with inner surfaces of the vessel at folds in the occlusion balloon when the occlusion balloon is partially inflated and in engagement with the inner surfaces.

DETAILED DESCRIPTION OF THE INVENTION

Certain terminology is used in the following description for convenience only and is not limiting. Unless specifically set forth herein, the terms “a”, “an” and “the” are not limited to one element but instead should be read as meaning “at least one”. The words “right”, “left”, “lower” and “upper” designate directions in the drawings to which reference is made. The words “inwardly” or “distally” and “outwardly” or “proximally” refer to directions toward and away from, respectively, the patient's body, or the geometric center of the preferred occlusion catheter systems and related parts thereof. The words, “anterior”, “posterior”, “superior,” “inferior”, “lateral” and related words and/or phrases designate preferred positions, directions and/or orientations in the human body to which reference is made and are not meant to be limiting. The terminology includes the above-listed words, derivatives thereof and words of similar import.

Referring toFIGS.1-4, a first preferred embodiment of an occlusion catheter system, generally designated10, includes a proximal catheter shaft11a, a strong and stiff central shaft or hypotube11band a distal catheter shaft11c. The proximal catheter shaft11ahas a central lumen that surrounds a proximal end of the central shaft11band is attached to an inflation hub12at its proximal end. In the first preferred embodiment, the central shaft11bis a hypotube11bwith an internal lumen, typically for collecting pressure data via pressure head, delivering medications or instruments to the distal end of the occlusion catheter system10or otherwise providing a lumen to the distal end of the system10. The central shaft11bmay be solid or have the central lumen of the hypotube11band preferably provides strength and stiffness to the system10in both configurations.

Marker bands11mare preferably attached to the hypotube11bproximate proximal and distal ends of the occlusion balloon14for location and identification of the position of the occlusion balloon14using fluoroscopy or other visualization techniques or systems. The proximal catheter shaft11aalso preferably includes depth markings33on its external surface that assists the user in properly placing the catheter system10during use by indicating the depth of insertion, as indicated by the depth markings33. The distal catheter shaft11cincludes an atraumatic tip or a P-tip13that unfolds to a generally straight insertion configuration when the catheter is inserted into a vessel3and a biased or relaxed configuration when positioned within the patient's vessel3. An occlusion balloon14is connected at a proximal end to an open distal end of the proximal catheter shaft11aand at a distal end to the distal catheter shaft11c. A proximal sensor15ais positioned adjacent the proximal end of the balloon14and a distal sensor15bis positioned adjacent the distal end of the balloon14. The proximal and distal sensors15a,15bare preferably comprised of pressure sensors and may be electronic pressure sensors positioned directly on the catheter shaft, a port for a fluid lumen for measuring pressure based on pressure head, a separate pressure sensor positioned adjacent the catheter shaft or other pressure sensing mechanisms or methods that facilitate pressure or other measurement at the desired locations. The balloon14is preferably comprised of a large diameter, semi-compliant or non-compliant balloon14. A pressure-relief or pop-off valve16is preferably connected to a catheter hub16at the proximal end of the proximal catheter shaft11a. The pressure-relief or pop-off valve16may be positioned in close relation to the or on the inflation hub12, such as proximal to the balloon valve or stopcock12cin a molded pressure relief fitting. The pressure-relief or pop-off valve16can be used to prevent the balloon14from overinflating.

In the first preferred embodiment of the occlusion catheter system10, the occlusion balloon14is comprised of a semi-compliant or substantially non-compliant balloon mounted to the proximal and distal catheter shafts11a,11c. Although not so limited, a non-compliant or semi-compliant balloon14generally has growth of approximately two to seven percent (2-7%) within the working range (balloon pressure) when inflated, a semi-compliant balloon has growth of approximately seven to twenty percent (7-20%) within the working range (balloon pressure) when inflated and a compliant balloon has growth of approximately greater than twenty percent (20%+) within the working range (balloon pressure) when inflated. Compliant balloons14may have growth of approximately one to three hundred percent (100-300%) within the working range (balloon pressure) when inflated. The occlusion balloon14has a relatively large blown diameter D, preferably approximately twenty-five to thirty-five millimeters (˜25-35 mm), that is configured to be approximately ten to sixty percent (10-60%) larger than the vessel3into which the balloon14is inserted and inflated for occlusion. The semi-compliant balloon14is, therefore, only partially inflated when its outer surface comes into full diametric contact with the inside of the target vessel3and folds14aremain at the outer surface of the balloon14. In this partially inflated configuration, the semi-compliant balloon14has a partially inflated diameter d, wherein the folds14aare formed. These folds14acreate channels15with the inner surfaces of the vessel3or with portions of the outer surface of the balloon14that allow partial perfusion or blood flow past the balloon14under the blood pressure within the vessel3. The cross-hatching within the folds14aofFIG.1Arepresent blood or fluid flowing through the folds14a, although the folds14awould otherwise be open in this partially inflated configuration.

The preferred pressure-relief valve16mounted to the catheter hub12is configured to prevent the balloon14from overinflating so that the balloon14does not burst and the vessel3is not damaged during the procedure. In the first preferred embodiment, the pressure-relief valve16is mounted in the fluid flow path further from the occlusion balloon14than the stopcock or balloon valve12c. If the pressure relief valve16is mounted closer to the occlusion balloon14in the fluid flow path for inflation of the occlusion balloon14, the pressure relief valve16remains active or able to relieve pressure during the occlusion period. Momentary pressure increases in the vessel3during the occlusion period may result in release of pressure by the pressure-relief valve16. The system10, however, is not significantly impacted by positioning the pressure-relief valve16closer to the occlusion balloon14in the fluid flow than the stopcock or balloon valve12cand is not limited to being positioned either further way from or closer to the occlusion balloon14in the fluid flow than the stopcock or balloon valve12c.

In the partially inflated configuration when the outer surface of the balloon14initially engages the inner surfaces3aof the vessel3(FIG.1A), the large diameter, semi-compliant balloon14has the folds14ain almost all aortas, approximately greater than ninety-five percent (95%) of the patient population of aortas, which allows for partial occlusion utilizing the oversized, semi-compliant balloon14in nearly all patient aortas. The folds14aand the inner walls of the vessel3define channels15that facilitates blood flow past the occlusion balloon14. The pressure relief valve16preferably prevents the user from overinflating the balloon14, thereby preventing aortic rupture/dissection or rupture of the balloon14, but still allowing nearly all patient population aortas, to be occluded.

The preferred catheter system10may include the proximal and/or distal pressure sensors15a,15b, flow sensors, temperature sensors and other sensors that collect data related to the procedure above and/or below the balloon14. The system10may also include a display on the inflation hub12or otherwise positioned for review by the user that is in wired or wireless contact with the pressure sensors15a,15band other sensors so that the user is able to monitor the procedure and characteristics of the patient during the procedure. The use of the pressure sensors15a,15band the related sensors with a controller or control hub200may also facilitate closed loop control of the catheter system10during use to modulate balloon volume to achieve a desired set point (i.e. proximal/distal blood pressure, temperature, flow, etc.). The pressure sensors15a,15bmay be comprised of pressure sensors that measure pressure by fluid pressure head, electronic pressure sensors or other sensors that are able to measure pressure of fluid in the patient's vessel13, within the occlusion balloon14or otherwise within the system10.

The combination of the pop-off or pressure-relief valve16and the non-compliant, semi-compliant or compliant balloon14, which is properly sized for the vessel3, allow the user to inflate the balloon14safely until the pop-off or pressure-relief valve16releases liquid or other inflation medium, as shown inFIG.2-2B. The preferred occlusion catheter system10is configured for all reasonable vessel3sizes or diameters of the aorta, generally up to approximately twenty-eight and six tenths millimeters (˜28.6 mm). Then when deflating from full occlusion and approaching full occlusion, the folds14ain the balloon14open enough to allow some blood flow in the channels15defined by the folds14aand/or the inner surfaces3aof the vessel3, thereby providing the user with a good degree of partial occlusion to limit shock to the patient's system of a quick change in pressure above and below the balloon14. Specifically, as is shown inFIGS.2-2B, the non-compliant or semi-compliant balloon14exhibits a slow and gradual increase in internal balloon pressure during an initial balloon volume increase and then a sharp increase in pressure with limited increase in balloon volume or inflation fluid introduction after full occlusion. The range of inflation fluid introduction and removal near full occlusion is, therefore, relatively forgiving for the non-compliant or semi-compliant balloon14just below full occlusion pressures and volumes, when oversized for the associated vessel3, allowing the user to readily control partial occlusion below the full occlusion range. The compliant balloon14has a more consistent balloon pressure vs. balloon volume slope below and above full occlusion when oversized for the associated vessel3. When properly sized and configured, the compliant, semi-compliant and non-compliant balloons14of the preferred occlusion catheter system10provide partial and full occlusion and are prevented from rupture of the balloon14and rupture of the vessel3by pressure release from the pop-off or pressure-relief valve16. The semi-compliant or non-compliant balloon14also provides a clear tactile indication to the user that the balloon14has come into direct facing engagement with the inside surfaces of the vessel3that provides an opposite reaction force to the expanding occlusion balloon14or has reached its full blown diameter D based on the steep pressure increase with relatively little inflation medium introduction into the balloon14, as shown inFIG.2. This facilitates the pressure-relief valve16releasing pressure well below an unsafe region of inflation where vessel3rupture or balloon rupture could potentially occur.

Referring toFIGS.2-2C, balloon volume in milliliters (mL) vs. balloon pressure in pounds per square inch (psi) are shown for various occlusion balloon and vessel3configurations and scenarios.FIG.2shows generic compliant and semi-compliant or non-compliant balloon pressure vs. balloon volume curves wherein the compliant balloon14stretches enough to soften at the point when the vessel3is occluded and, thus, may rupture before the crack pressure of the pop-off or pressure-relief valve16is reached (FIG.2C), while the non-compliant or semi-compliant balloon14actuates the pressure-relief or pop-off valve16before either the balloon14or vessel3rupture.FIG.2A, shows a non-compliant or semi-compliant twenty-five millimeter (25 mm) balloon14and a prior art compliant balloon14that both actuate the pressure-relief or pop-off valve16before either balloon or vessel3rupture. The balloons14ofFIG.2Aare inserted and actuated in a fifteen and one-half millimeter (15.5 mm) tube or simulated vessel3and the pressure-relief or pop-off valve16has an actuation range of eight pounds per square inch with a tolerance of two pounds per square inch (8 psi±2 psi). The compliant balloon14reaches full occlusion of the vessel3at approximately five and eight tenths milliliters (5.8 mL) and three pounds per square inch (3 psi), while the non-compliant or semi-compliant balloon14reached full occlusion of the vessel3at approximately eight and eight tenths milliliters (8.8 mL) and two and one tenth pounds per square inch (2.1 psi).

FIG.2B, shows the same non-compliant or semi-compliant and compliant balloons14inflated in a nineteen millimeter tube or simulated vessel3with the same the pressure-relief or pop-off valve16having the same actuation range of eight pounds per square inch with a tolerance of two pounds per square inch (8 psi±2 psi). The compliant balloon14reaches full occlusion of the vessel3at approximately seven and eight tenths milliliters (7.8 mL) and three pounds per square inch (3 psi), while the non-compliant or semi-compliant balloon14reached full occlusion of the vessel3at approximately eleven and eight tenths milliliters (11.8 mL) and two and two tenths pounds per square inch (2.2 psi). Both the compliant and non-compliant or semi-compliant balloons14enter the pop-off range prior to rupture, thereby actuating the pop-off or pressure-relief valve16before the balloon ruptures.

FIG.2C, shows the same compliant balloon14inflated in a twenty-five and four tenths millimeter (25.4 mm) tube or simulated vessel3with the same pressure-relief or pop-off valve16having the same actuation range of eight pounds per square inch with a tolerance of two pounds per square inch (8 psi±2 psi). In the scenario and configuration ofFIG.2C, the pressure in the compliant balloon14never exceeded the crack pressure of the pop-off or pressure relief valve16, so the valve16does not open and the balloon14ruptures. For smaller vessels3, for example, approximately twenty millimeters (20 mm) or smaller, the compliant and non-compliant or semi-compliant balloons14function similarly (i.e. pressure in the balloons14stays low through full occlusion, then starts to increase quickly after full occlusion has been reached). When vessels3are larger than about twenty millimeters (20 mm), the compliant balloons14no longer have this rapid increase in balloon pressure after full occlusion. The reason is the balloon14has stretched enough at that point that the balloon14is becoming less stiff as additional volume is added. This results in the balloon pressure staying relatively low, all the way to rupture. This configuration and scenario doesn't allow the pop-off valve16to open before balloon14ruptures, because the pressure is too low to actuate the pop-off valve16. This effect is highly depending on the blown diameter D of the balloon14in comparison to the size. If, as a non-limiting example, a compliant balloon was blown to thirty millimeters (30 mm) and placed in a relatively small vessel3, such as a fifteen millimeter (15 mm) vessel3, it is possible that the balloon wouldn't have stretched much by the time it reaches full occlusion and the pressure would rise significantly like a non-compliant or semi-compliant balloon. Both a compliant and non-compliant or semi-compliant balloons could work for this application if it was blown significantly large.

For relatively small vessels3, such as the fifteen and one-half and nineteen millimeter (15 mm and 19 mm) tubes or simulated vessels3, shown inFIGS.2A and2B, the compliant and non-compliant or semi-compliant balloons14have relatively similarly shaped pressure vs. volume curves. In these simulations, the compliant balloon14hasn't significantly stretched when the compliant balloon14reaches full occlusion, such that the wall of the compliant balloon14is still relatively thick and the pressure in the balloon14rises relatively quickly, similar to the non-compliant or semi-compliant balloon14, although the slope of pressure increase of the non-compliant or semi-compliant balloon14is steeper starting at a greater inflation fluid volume. Conversely, for large diameter vessels3where the compliant balloon14is not oversized for the vessel3, the compliant balloons14can have a shallow slope and the pressure doesn't increase significantly after occlusion, thereby potentially leading to rupture at a relatively low pressure (FIG.2). This configuration could lead to the compliant balloon14rupturing before the pop-off valve16is actuated. For the pop-off valve16to function successfully, meaning the valve16always opens before balloon14or vessel3rupture, the valve16remains closed or unactuated during inflation of the balloons14to full occlusion and the valve16opens or is actuated before either: (1) the balloon14ruptures or the blood vessel3ruptures.

Referring toFIGS.4and5, the preferred occlusion catheter system10may alternatively include a pressure gauge16a(FIG.4) or a threshold pressure sensor16b(FIG.5) mounted to the hub12for monitoring the pressure within the balloon14. The pressure gauge16amay include markings or indications related to a safe inflation zone or range for the associated balloon14and the threshold pressure sensor16bmay include a visual indication to notify the user that a maximum pressure has been reached within the balloon14. The threshold pressure sensor16bmay also indicate to the user that the threshold pressure has been reached by a light, a buzzer, vibration emission or another related indication to the user that the threshold pressure is reached.

Referring toFIGS.3,4and6, the first preferred occlusion catheter system10includes an inflation pressure source17that is preferably comprised of a syringe that may be manually operated by the user. The system10is not limited to including the inflation pressure source17comprised of the syringe and may include a compressor or other pressure introducing mechanism that is able to provide a pressurized inflation medium into the occlusion balloon14through the proximal catheter shaft11a, which may be controlled by the user manually or via a controller. The system10may, alternatively, include a comparatively large syringe17awith a large bore to limit the amount of pressure that can be inserted into the balloon14by a users hand.

Referring toFIG.7, a second preferred occlusion catheter system20has a similar construction to the first preferred occlusion catheter system10and like reference numbers are utilized to identify like features of the second preferred occlusion catheter system20with a number “2” prefix replacing the “1” prefix to distinguish the features of the occlusion catheter system10of the first preferred embodiment from the occlusion catheter system20of the second preferred embodiment.

In the second preferred occlusion catheter system20, a complaint, large-diameter balloon24is mounted to the proximal and distal catheter shafts21a,21cin place of the non-compliant or semi-compliant balloon14of the first preferred embodiment. When the compliant balloon24is inflated in a vessel3smaller than the blown diameter D, the folds24ain the balloon24create flow channels for good partial occlusion. When full occlusion has been reached, the balloon24stretches axially to facilitate additional inflation medium volume in the balloon24without causing the blood vessel3to stretch further, as shown inFIG.7. In addition, the greater length in the contact between the outer surfaces of the balloon24and the inner surfaces3aof the vessel3facilitate full occlusion of the vessel3as the folds24aare released or removed as the balloon24stretches.

Referring toFIG.8, the second preferred catheter system20, as well as the first preferred catheter system10, may mount the pop-off or pressure-relief valve (not shown) at various locations on the proximal or distal catheter shafts21a,21cor on the hub22. The pop-off or pressure-relief valve may be mounted nearly anywhere on the catheter system20that permits communication between the valve and the inflation medium that inflates the balloon24. For example, the pop-off or pressure-relief valve, as well as the pressure gauge or sensor16aand the threshold pressure sensor16b, may be located at the catheter hub22, in-line with the balloon extension line, at the balloon pressure relief fitting, proximal to the stopcock, on the catheter shaft or near the balloon.

Referring toFIGS.9and10, first and second alternative occlusion balloons8,9may be mounted to any of the preferred occlusion catheter systems, including the first and second preferred occlusion catheter systems10,20, described herein. The first and second alternative occlusion balloon8,9are tapered to create an extended range of partial occlusion by allowing the balloon8,9to grow axially. The first and second preferred tapered balloons8,9reduce the likelihood of the balloons8,9“windsocking” or pushing the balloon fluid or inflation medium to the proximal or downstream side of the balloons8,9near the proximal catheter shaft11a,21awhen the balloons8,9are in the vessel3and subjected to blood pressure within the vessel3.

Referring toFIG.11, a third preferred occlusion catheter system30has a similar construction to the first and second preferred occlusion catheter systems10,20and like reference numbers are utilized to identify like features of the third preferred occlusion catheter system30with a number “3” prefix replacing the “1” and “2” prefixes to distinguish the features of the occlusion catheter systems10,20of the first and second preferred embodiments from the occlusion catheter system30of the third preferred embodiment. The third preferred occlusion catheter system30includes an occlusion balloon34comprised of an oversized, non-compliant or semi-compliant balloon34xpaired with a non-compliant or semi-compliant, smaller diameter spine balloon34y. In a partially inflated configuration, balloon folds34aare formed at the outer surface of the oversized, non-compliant or semi-compliant balloon34xthat form flow channels with the inner surfaces3aof the vessel3for partial occlusion capability in small vessels3. In addition, the spine balloon34y, the inner surfaces3aof the vessel3and the surfaces of the oversized balloon34xdefine flow channels for partial blood flow, particularly when the occlusion balloon34is positioned within a large vessel3.

Referring toFIG.12, a fourth preferred occlusion catheter system40has a similar construction to the first, second and third preferred occlusion catheter systems10,20,30and like reference numbers are utilized to identify like features of the fourth preferred occlusion catheter system40with a number “4” prefix replacing the “1,” “2” and “3” prefixes to distinguish the features of the occlusion catheter systems10,20,30of the first, second and third preferred embodiments from the occlusion catheter system40of the fourth preferred embodiment. In the fourth preferred embodiment, a comparatively longer occlusion balloon44is mounted to the proximal and distal catheter shafts41a,41c. The comparatively longer occlusion balloon44is configured to extend the range of partial occlusion because comparatively greater length L makes partial occlusion more gradual. In the fourth preferred embodiment, the occlusion balloon44has a length L of approximately thirty to one hundred millimeters (30-100 mm) for occlusion of a typical patient's aorta.

Referring toFIGS.13-15, fifth, sixth and seventh preferred occlusion catheter systems50,60,70have a similar constructions compared to the first, second, third and fourth preferred occlusion catheter systems10,20,30,40and like reference numbers are utilized to identify like features of the fifth, sixth and seventh preferred occlusion catheter systems50,60,70with the numbers “5,” “6,” and “7” prefixes replacing the “1,” “2,” “3” and “4” prefixes, respectively to distinguish the features of the occlusion catheter systems10,20,30,40of the first, second, third and fourth preferred embodiments from the occlusion catheter systems50,60,70of the fifth, sixth and seventh preferred embodiments. In the fifth, sixth and seventh preferred embodiments, the systems50,60,70include an offset occlusion balloon54,64,74mounted to the proximal catheter shaft51a,61a,71aand the distal catheter shaft51c,61c,71c. The offset occlusion balloons54,64,74could be utilized with any of the preferred occlusion catheter systems10,20,30,40,50,60,70described herein. The fifth, sixth and seventh preferred occlusion balloons54,64,74are designed and configured to strengthen the occlusion balloons54,64,74where they stretch the most. In the fifth preferred embodiment, the spine balloon54yinhibits expansion of the oversized occlusion balloon54xsuch that the lower part of the oversized occlusion balloon54xstretches the most. This effect is caused by the restraining nature of the non-compliant or semi-compliant spine balloon54ylimits the occlusion balloon54xfrom growing in the direction toward the spine balloon54y. In the sixth preferred embodiment, the occlusion balloon64is constructed of a compliant balloon64, although the balloon64may also be non-compliant or semi-compliant, that is designed and configured or blown such that the occlusion balloon64is offset relative to the longitudinal axis defined by the proximal and distal catheter shafts61a,61cand the hypotube61b. In the seventh preferred embodiment, the occlusion balloon74is constructed of a non-compliant or semi-compliant oversized and offset occlusion balloon74xand an adjacent spine balloon74y. The oversized occlusion balloon74xis designed and configured to be offset from the longitudinal axis defined by the proximal and distal catheter shafts71a,71cand the spine balloon74yis positioned on the limited diameter side of the oversized occlusion balloon74x.

Referring toFIGS.16-18, an eighth preferred occlusion catheter system80has a similar construction to the first, second, third, fourth, fifth, sixth and seventh preferred occlusion catheter systems10,20,30,40,50,60,70and like reference numbers are utilized to identify like features of the eighth preferred occlusion catheter system80with a number “8” prefix replacing the “1,” “2,” “3,” “4,” “5,” “6,” and “7” prefixes to distinguish the features of the occlusion catheter systems10,20,30,40,50,60,70of the first, second, third, fourth, fifth, sixth and seventh preferred embodiments from the occlusion catheter system80of the eighth preferred embodiment.

In the eighth preferred embodiment, the occlusion balloon84has a proximal end84pand a distal end84d. To connect the balloon84to the proximal catheter81aand the distal catheter84c, the balloon proximal end84pis butt welded to the proximal catheter81a(FIG.17) and the balloon distal end84dis butt welded to the distal catheter81c(FIG.18). Butt welding the balloon proximal and distal ends84p,84dto the proximal and distal catheters81a,81cmaintains an outer diameter Do of the catheter to limit the size of the insertion sheath18required for introducing the catheter system80into the patient. The outer diameter Do is preferably small enough for insertion into the introducer sheath or insertion catheter18having an inner introducer diameter of seven French gauge (7 Fr) or less, such as six French gauge (6 Fr). The seven French (7 Fr) or smaller introducer sheath18typically results in the access site through the patient's skin and into the vessel3being closed by holding manual pressure for a period of time, such as twenty to thirty minutes (20-30 min). If the introducer sheath18has the introducer diameter R greater than seven French (7 Fr), a surgical repair of the access site may be required, thereby further complicating the procedure. In the first preferred embodiment, the outer diameter Do of the proximal catheter shaft11aand the distal catheter shaft11care six French gauge (6 Fr) or less to accommodate sliding through the insertion sheath18having the inner diameter of seven French gauge (7 Fr) with the occlusion balloon14in the folded configuration and retained by the peel away sheath25at a diameter of approximately seven French gauge (7 Fr) or less. The outer diameter Do of six French gauge (6 Fr) or less in combination with the seven French gauge (7 Fr) introducer sheath inner diameter provides an annular space between the proximal catheter shaft11aand the introducer sheath18. If the annular gap is flushed and prepared with saline solution, the annular gap facilitates use of fluid column pressure monitoring for measuring blood pressure below the occlusion balloon14, near the terminus of the introducer sheath18, if a side arm or port99of the introducer sheath18is connected to a pressure sensor or monitor98. The additional pressure monitor (not shown inFIG.1E) permits the surgeon or medical personnel to measure pressure separate from the pressure sensors15a,15bthat are on the occlusion catheter system10. The occlusion catheter system10may also include a pressure monitor98that is in fluid communication with the hypotube lumen9athrough the arterial line extension line12bto measure pressure head.

In addition, the butt welding also facilitates maintaining an inner diameter DIof the proximal catheter81asuch that flow of inflation medium through the space or proximal lumen between the hypotube81band the proximal catheter81ais not limited or constricted at the connection of the balloon proximal end84pand the proximal catheter shat81a. At the proximal side of the balloon84, the balloon proximal end84pis preferably positioned against the distal end of the proximal catheter81aand butt welded with the hypotube81bpositioned within a lumen within the proximal catheter81aand the balloon proximal end84pthat facilitates flow of the inflation medium into and out of the balloon84. At the distal side of the balloon84, the balloon distal end84dis preferably positioned against the proximal end of the distal catheter81cand butt welded with the balloon distal end84d. The distal catheter84cand the distal balloon end84dare also both preferably in facing engagement with and secured, potentially lap welded, to the hypotube81bto prevent inflation fluid from escaping the distal end of the balloon84. Minimizing restriction of the lumen between the lumens within the proximal catheter shaft81aand the balloon proximal end84pand the hypotube81bis preferred to facilitate rapid inflation or filling of the balloon84with the inflation medium without causing the pop-off or pressure-relief valve16to open prematurely, while also maintaining at low profile of the catheter and facilitating rapid deflation of the balloon84, if necessary.

The eighth preferred occlusion catheter system80may also include a relatively thin reinforcement band84zthat overlaps the butt weld at the connection between the proximal catheter81aand the balloon proximal end84pto increase strength and rigidity of the connection without significantly adding to the profile or outer diameter Do of the catheter system80at the proximal end of the balloon84and of the distal catheter shaft81c. The reinforcement band84zmay also be utilized at the distal end of the balloon84at the butt weld between the distal catheter shaft81cand the balloon distal end84d. The outer diameter Do is preferably six French gauge (6 Fr) or less for insertion through the seven French gauge (7 Fr) inner diameter of the introducer sheath18to utilize the gap between the outer diameter Do and the inner diameter of the introducer sheath18for fluid column pressure monitoring. The diameter at the reinforcement band84zand the occlusion balloon14in the folded configuration is less than seven French gauge (7 Fr) for insertion through the seven French gauge (7 Fr) introducer sheath18.

Referring toFIGS.1-6, the occlusion catheter system10of the first preferred embodiment is designed to fully or partially occlude the vessel3having a vessel diameter DVaccessed with an introducer sheath18having an inner introducer diameter DRof seven French gauge (7 Fr) or less, such as six French gauge (6 Fr). In the first preferred embodiment, the introducer sheath18is comprised of a substantially cylindrical sheath that may have a sharpened distal end for insertion through the patient's skin into the vessel3and may have a flared or funnel-shaped proximal end for receipt of the straightened P-tip13, distal catheter shaft11c, folded occlusion balloon14, and proximal catheter shaft11aduring the insertion and placement process. The occlusion balloon14preferably has a limited thickness to accommodate low-profile the folded configuration for insertion through the seven or six French gauge (7 or 6 Fr) introducer sheath18when folded over the central shaft11b. In the preferred embodiment, the inner introducer diameter DRof the seven French gauge (7 Fr) introducer sheath18is approximately two and thirty-three hundredths millimeters (2.33 mm) and the inner introducer diameter DRof the six French gauge (6 Fr) introducer sheath18is approximately two and zero hundredths millimeters (2.00 mm). The inner introducer diameter DRis preferred to minimize the puncture in the patient's skin and vessel3and to simplify the procedure, as use of introducer sheath's18with inner introducer diameters DRgreater than seven French gauge (7 Fr) typically requires additional and specialized medical personnel. The vessel diameter DVof zones I and III of over ninety-nine percent (99%) of typical patient's is approximately twenty-six millimeters (26 mm) or less such that the balloon blown diameter D of approximately twenty-five to thirty-five millimeters (25-35 mm) and more preferably thirty millimeters (30 mm) will result in full occlusion of the vessel3when the semi-compliant occlusion balloon14is inflated to the balloon blown diameter D.

The proximal catheter shaft11apreferably includes a proximal lumen therein formed between inner surfaces of the proximal catheter shaft11aand outer surfaces of the central shaft11b. The proximal lumen is preferably in fluid communication with an inflation cavity14binside the balloon14wherein pressurized fluid is received to blow-up the occlusion balloon14during use or to transform the occlusion balloon14from the folded configuration, wherein the folded occlusion balloon14is folded around the central shaft11bfor insertion through the introducer sheath18, and the inflated or partially inflated configurations, wherein the occlusion balloon14occludes, typically when inflated to the diameter of the blood vessel3when the vessel3provides an opposition force to further expansion of the occlusion balloon14, or partially occludes the vessel13, typically when the folds14aare retained in the semi-inflated configurations.

The central shaft or hypotube11bis positioned partially within the proximal lumen of the proximal catheter shaft11a, thereby defining the proximal lumen for introduction of the inflation fluid and to provide strength and stiffness to the system10. The central shaft or hypotube11bmay be substantially solid from its proximal to its distal end or may include the hypotube lumen extending therethrough for pressure measurement by pressure head, introduction of medications to the distal end of the system10or otherwise for access through the hypotube lumen to the distal end of the system10beyond the occlusion balloon14during operation when the occlusion balloon14is inflated. The central shaft or hypotube11bextends beyond the distal end of the proximal catheter shaft11afor connection to the distal catheter shaft11cand spans through the inflation cavity14b. The hypotube lumen may also be configured for introduction of a guidewire for placement of the catheter system10in the patient's vessel13.

In the first preferred embodiment, the proximal catheter shaft11aincludes depth markings33on an outer surface. The depth markings33may be comprised of hashes or line marks at predetermined distances on the length of the proximal catheter shaft11a, such as markings at every inch or centimeter along the outer surface of the proximal catheter shaft11a. The depth markings33may alternatively be comprised of zone markings, such as zone I and zone III representing locations in the patient's vessel3, typically the aorta, wherein the occlusion balloon14is likely positioned during use. The preferred location of the occlusion balloon14in zone I preferably extends from the original of the left subclavian artery to the coeliac artery, zone II preferably extends from the coeliac artery to the most caudal renal artery and zone III preferably extends distally from the most caudal renal artery to the aortic bifurcation.

The inflation hub12of the preferred embodiment is connected to a proximal end of the proximal catheter shaft11aand to a proximal end of the central shaft or the hypotube11b. The inflation hub12includes a balloon extension line12aand an arterial line extension line12bthat are positioned generally proximally on the catheter. The balloon extension line12aand the arterial line extension line12bare preferably comprised of medical tubing with pressure relief fitting and a balloon valve12cand a monitor valve12dthereon, respectively. A syringe or other pressurization device may be attached to the pressure relief fitting of the balloon extension line12aand the arterial line extension line12bto pressurize the occlusion balloon14or connect to the hypotube lumen9bthrough the arterial line extension line12b. The balloon extension line12ais in fluid communication with the proximal lumen9abetween the inner surfaces of the proximal catheter shaft and the central shaft11band the inflation cavity14b. The balloon extension line12aalso includes the pressure relief valve16thereon that is positioned proximally relative to the balloon valve12c, such that the inflation or balloon valve12cis positioned closer to the occlusion balloon14than the pressure relief valve16. In operation, the pressure relief valve16will release inflation fluid pressure only during inflation of the occlusion balloon14when the balloon valve12cis open. The pressure relief valve16, therefore, does not operate when the balloon valve12is closed. The pressure relief valve16is preferably comprised of a ball valve that seats on an O-ring and is urged onto the O-ring by a spring for appropriate sealing when the pressure relief valve16is not intended to be in the open position.

In the first preferred embodiment, the occlusion balloon14has a proximal end20aand a distal end20b. The proximal end20ais connected to proximal catheter shaft11aand the distal end20bis connected to the distal catheter shaft11c. The occlusion balloon14preferably has the blown diameter D of approximately twenty-five to thirty-five millimeters (25-35 mm). The occlusion balloon14is positioned in a folded configuration wherein the occlusion balloon14is folded around the central shaft or hypotube11band an inflated configuration wherein the occlusion balloon14is expanded to the blown diameter D. The occlusion balloon14is in the folded configuration, the distal catheter shaft11cand the proximal catheter shaft11aare movable through the introducer sheath18for introduction into the vessel3. The relatively large occlusion balloon14, preferably between twenty-five to thirty-five millimeters (25-35 mm), in the folded configuration is insertable through the introducer sheath18having the inner introducer diameter DIof seven French gauge (7 Fr) or less. The procedure to occlude the vessel3is substantially less invasive and complicated when utilizing the introducer sheath18having the inner introducer diameter DIof seven French gauge (7 Fr) or less.

In the preferred embodiment, a peel-away sheath25is pre-positioned over the occlusion balloon14in the folded configuration to maintain the folded configuration. The pressure relief valve16is preferably primed before use by attaching an inflation syringe to the pressure relief fitting of the balloon extension line12a, opening the balloon valve12cand injecting inflation fluid until the pressure relief valve16opens or releases pressure. Since the peel-away sheath25is covering the occlusion balloon14, the occlusion balloon14preferably does not inflate. Negative pressure on the syringe plunger will then be applied to remove the remaining fluid/air from the balloon lumen.

The pressure relief valve is a safety feature designed to open and vent inflation medium if the balloon is over-inflated. If the balloon is inflated properly (not over-inflated), the pressure relief valve will not need to open. If the valve does open due to over-inflation, it will shut automatically when the balloon lumen has vented sufficient volume.

This design may be used with a guidewire up to thirty-eight thousandths of an inch (0.038″) in diameter if desired. It is still designed to be used without a guidewire, but warnings regarding use with a guidewire will be removed.

The proximal and distal sensors15a,15band potentially a pressure sensor within the occlusion balloon14, preferably transmit signals to a controller or control hub200that may be incorporated into the inflation hub12and the pressures are preferably displayed as pressure readings on a display screen or display screens mounted to the occlusion catheter system10, preferably on the control hub200or the inflation hub12. The control hub200is preferably mounted on a proximal portion of the inflation hub12and includes the integrated LCD screen to display the pressures from the pressure sensors or other sensors15a,15b. The display screen of the control hub200may display the pulsatile blood pressures201,202,203,204above and/or below the occlusion balloon14, an occlusion percentage205in the vessel13or other desired pressure, temperature, pH or related patient or system data acquired from the system10. The control hub200may also include a guidewire orifice206that accommodated use of a guidewire. The control hub200also preferably includes a power button207to turn the control hub200off and on during use. The balloon extension line12aalso preferably extends from the control hub200. The control hub200may be configured, operate and function similarly to the control hub described in U.S. patent application Ser. No. 15/573,054, published as U.S. Patent Application Publication No. 2019/0076152 and titled, “System and Method for Low Profile Occlusion Balloon Catheter,” which is incorporated herein by reference in its entirety, particularly with respect to the control hub.

Monitoring the pressures displayed on the display screen allows the user to observe blood pressure responses to the various inflation configurations of the occlusion balloon14, in real time and in a convenient location, as the pressurization of the occlusion balloon14is modified. The positioning of the control hub200on the inflation hub12with the display screen thereon is preferred, versus a vital monitor that may or may not be conveniently located relative to the procedure for observation by the technician or physician. The display of the pressures from the pressure sensors or other sensors15a,15bon the display screen with a localized signal processor acts as a means for open-loop feedback of the occlusion catheter system10. The displays may display the pressure inside the occlusion balloon14from an internal balloon pressure sensor, the pressure proximally of the occlusion balloon14from the proximal pressure sensor15aand the pressure distally of the occlusion balloon14from the distal pressure sensor15b. The proximal and distal sensors15a,15bare not limited to pressure sensors and may be comprised of alternative sensors for acquiring data related to the system10or the patient, such as temperature, pH, flow rate and related data. The senor data may also be transmitted to a central processor in a wired or wireless manner for depiction, manipulation and/or processing. For example, the collected data may be wirelessly transmitted to a remote central processor for storage and depiction on a larger display, such as a television screen, tablet, vital sign monitor or related equipment for viewing by a larger audience, manipulation and recording or storage. The displays may also include other collected data or calculated information for the user, such as a pressure ratio between the distal and proximal pressure sensors15a,15b, an indication of the degree or percentage of occlusion of the vessel3based on an algorithm that uses the proximal and distal pressures15a,15bto provide an approximation of the degree of occlusion. The degree of occlusion could be displayed as a percentage, on a scale, such as 1-5, as a dial gauge or in other manners that provide an estimation of the degree of occlusion to the user.

The control hub200on the inflation hub12preferably includes the controller and a power source. The power source is preferably comprised of a battery or batteries stored in the control hub on the inflation hub12to power at least the display screen. The controller may include a circuit board to process signals, make calculations related to the collected data, control the operating components and perform related functions described herein.

In a non-limiting, preferred example, as conditions change within the patient with the occlusion balloon14positioned in the vessel3and in the partially or fully inflated configurations, the partial and distal sensors15a,15bprovide passive feedback to the practitioner to indicate the need for changes to the occlusion balloon's14volume to manage blood pressure distal and proximal to the occlusion balloon14. If the occlusion balloon14is inflated in a constricted vessel3, occlusion may be lost as the vessel3relaxes and the passive feedback can indicate to the practitioner that additional volume or pressure is required in the occlusion balloon14to maintain occlusion or a desired level of partial occlusion.

In operation in a non-limiting example, the controller200is preferably connected to the pressure sensors15a,15band other sensors, as is described herein, for management of the occlusion state of the occlusion balloon14in a closed loop configuration (full feedback). The controller200is powered on by depressing the power button207and can be set to maintain the distal and/or proximal pressures or the pressure ratio between the two by continually adjusting the volume or pressure of the fluid introduced into the occlusion balloon14using a preferably small, internal, locally powered pump in the controller200. The controller200may be set to maintain the proximal pressure measured by the proximal pressure sensor15aat approximately zero when maintaining full occlusion and at a pressure greater than zero when maintaining partial occlusion through creation of the blood flow channels at the folds14a. For partial occlusion, the controller200is preferably set to manage the pressure ratio or a pressure ratio within a range, to maintain a user-specified amount of partial occlusion. The controller200may also be configured to permit the user to select a distal pressure setpoint that sets a desired pressure for the distal pressure sensor15b, which is typically the upstream side of the occlusion balloon14when the system10is positioned in the artery or vessel3, such as the aorta (FIG.1E). The controller200preferably adjusts the fluid volume in the occlusion balloon14until the setpoint is achieved. The controller200may also be based on a proximal side setpoint associated with the proximal pressure sensor14aor a target degree of occlusion (i.e. a preferred percentage of occlusion or pressure ratio). The balloon valve12cmay be utilized to switch between a manual pressurization of the system10, wherein pressure is manually introduced into and withdrawn from the occlusion balloon14by the user, such as with a syringe101, and the above-described closed loop feedback configuration, wherein the controller200substantially controls the pressure within the occlusion balloon14.

In the preferred embodiment, the atraumatic tip or p-tip13has a generally circular profile and is flexible for positioning in the straightened insertion configuration from the biased circular profile. The atraumatic tip13is preferably secured to or co-molded with the distal catheter shaft11c. The guiding atraumatic tip13may be employed with any of the preferred embodiments of the occlusion catheter system10described herein. The guiding atraumatic tip13is preferably comprised of a polymeric cylindrical or tubular member that has a distal section formed into a generally flattened cylinder having two generally planar opposing surfaces and two generally curved opposing surfaces. The two generally planar opposing surfaces include an inner planar surface and an outer planar surface. The atraumatic tip13has a distally extending section that projects distally from the distal catheter shaft11cand a curved section continuous with the distally extending section that curves away from the central longitudinal axis of the occlusion catheter system10, then proximally toward the occlusion balloon14and subtends a generally circular arc toward the central longitudinal axis of the occlusion catheter system10. The angle of the curvature may be between about one hundred eighty degrees (180°) and three hundred fifty-five degrees (355°), more preferably between about two hundred seventy degrees (270°) and three hundred fifty degrees (350°) and even more preferably between about three hundred degrees (300°) and three hundred fifty degrees (350°) such that a gap is provided between the terminal end of the generally cylindrical flattened distal section and the more proximal surface of the atraumatic tip13. The distally extending section and curved section may alternatively be formed as a generally in-plane circular shape or may be formed as an out-of-plane generally helical shape, where a terminal end of the curved section is laterally displaced from the central longitudinal axis of the occlusion catheter system10. In this manner, the generally flattened distal section is characterized by a generally circular profile