Transmyocardial Jet Perfusion Device

Abstract

The present invention relates to hardware and methods for injecting a sufficient amount of cold saline or cryoprotectant solution directly into the left ventricle of a patient's or animal's heart during cardiac arrest or initial cardiac arrest, typically using a 14-18 gauge cannula with a retractable trocar, to generate cold blood flow through the two carotid arteries, the two vertebral arteries, and the brain to cool the brain or other vital organs. Generally, a sufficient amount of saline or cryoprotectant solution is injected under high enough pressure to create 30% of the baseline common carotid artery blood flow. The cannula mechanism includes a retractable trocar with a calibrated sharp tip, which, together with a surrounding flexible and rigid shield, diaphragm, and stopcock, provides a sterile, self-sealing system suitable for use in either the "field" or hospital environment.

Description

Technical Field

[0001] <Cross - Reference to Related Applications> This patent application claims priority to the following four U.S. provisional patent applications, each of which is hereby incorporated by reference in its entirety: U.S. Provisional Patent Application No. 63 / 126,119, filed December 16, 2020; U.S. Provisional Patent Application No. 63 / 126,130, filed December 16, 2020; U.S. Provisional Patent Application No. 63 / 132,165, filed December 30, 2020; and U.S. Provisional Patent Application No. 63 / 132,192, filed December 30, 2020.

[0002] <Field of the Invention> The present invention is a method and apparatus for inhibiting tissue metabolism in regions of the brain, and more particularly, a method and apparatus for inducing either local therapeutic hypothermia or systemic therapeutic hypothermia, or both.

Background Art

[0003] Systemic hypothermia therapy can dramatically slow the decline of neurological function in hypoxic or anoxic tissues. Hypothermia therapy has long been known to prevent brain injury during cardiac arrest. Initially thought to be due to a decrease in metabolism, it is now believed that the inhibition of hypothermia on triggering events during ischemia - reperfusion injury, due to the early and dramatic reduction of oxygen stores in hypothermic cardiac arrest, is the cause of hypoxic injury. Thus, it is known that hypothermia reduces the oxygen demand of tissues and suppresses the pathological processes that occur both during cardiac arrest and after circulatory recovery. For example, accidental immersion in cold water and the associated systemic hypothermia that results have consistently contributed to the neurological survival of accident victims who would otherwise have suffered irreversible brain damage. As a result of observing this phenomenon, medical practitioners have induced systemic hypothermia during various surgical procedures that cause hypoxia and anoxia in order to reduce both the patient's systemic metabolism and the associated overall oxygen demand and inhibit harmful processes.

[0004] In particular, hypothermia therapy has been widely used in cardiac and neurological surgical procedures that require inducing cardiac arrest to perform surgery safely. Hypothermia therapy has also been used after restoration of spontaneous circulation following cardiac arrest to reduce brain injury. Hypothermia induced before cardiac arrest is more effective than hypothermia induced after cardiac arrest, but clinical trials have shown some benefits in some cases for post-cardiac arrest hypothermia, and some EMS systems have adopted the prior art post-cardiac arrest hypothermia therapy described herein. Hypothermia induced by external means during cardiac arrest has yielded positive results in bench-top studies and is already being implemented today in some facilities as an additional treatment in parallel with cardiopulmonary resuscitation (CPR). CPR is beneficial during cardiac arrest but produces only about 10% of normal blood flow, which should be noted is not sufficient to prevent brain injury over any period of sustained CPR, which can be over 20 minutes. Under normothermic conditions, it is thought that about 30% of normal blood flow is necessary to prevent brain injury. While external cooling can be beneficial during cardiac arrest and CPR, there is a general consensus that only the surface brain structures are likely to benefit from external cooling and the deep structures will remain normothermic. When a cardiac arrest patient has hypothermia, typically in a cold water drowning scenario, good neurological outcomes have been achieved despite long periods of cardiac arrest with CPR being performed for several hours. As a result, rapid induction of cooling, particularly rapid induction of brain cooling, has demonstrated the potential to extend the current 20-minute barrier for CPR under normothermic conditions.

[0005] One of the current methods for improving outcomes compared to CPR is the use of veno-arterial extracorporeal membrane oxygenation, or VA ECMO, in the treatment of cardiac arrest. Recent studies using VA ECMO early in cardiac arrest have shown significantly improved cardiac arrest outcomes and also improved neurological outcomes. In such patients, CPR is replaced by blood flow from a VA ECMO device that mimics normal cardiac output and tissue perfusion. Once VA ECMO is applied, the patient is taken to the cardiac catheterization room, where coronary artery blockages are opened (and in some cases stents are inserted), and the heart is able to "start beating on its own" again. Placing a patient on VA ECMO is a very technical procedure that, even in the best hands, takes 10 minutes to perform, which severely limits the downtime and the transport time to a facility where this treatment can be performed. The time required to initiate VA ECMO treatment also limits the usefulness of VA ECMO in the hospital setting, albeit to a lesser extent, because even a few minutes' delay can significantly negatively impact neurological outcomes. Thus, while VA ECMO is an important technique for treating cardiac arrest patients, VA ECMO itself does not provide any "time-buying" benefit similar to the benefits that would be achieved if induced hypothermia were induced in a similar situation.

[0006] Currently, whole-body hypothermia can be induced relatively easily in the in-hospital environment, but at present, emergency induction of whole-body hypothermia in the out-of-hospital environment is difficult or virtually impossible. As a result, induced whole-body hypothermia is not currently part of pre-hospital emergency cardiac arrest care, such as cardiopulmonary resuscitation (CPR), despite the beneficial metabolic inhibition that such hypothermia provides and which is already widely known and well established. Similar emergency treatments for which hypothermia therapy has not yet been introduced include pre-hospital emergency treatment for patients with severe shock or stroke. As described above, post-cardiac arrest cooling is sometimes performed by healthcare providers via ad hoc application of cold packs and irregular infusion of cold intravenous fluids, but these cannot provide appropriate whole-body cooling in any kind of controlled manner.

[0007] Separately from the above, induced local hypothermia has been widely used for the non-hospital or pre-hospital treatment of various physiological conditions. Certain cold packs are standard equipment in emergency kits and are used to reduce peripheral blood flow and corresponding swelling in cases of contusions, insect stings or puncture wounds, nosebleeds, sprains, etc. Of course, cold compresses on the head have long been a standard means of relieving the symptoms of headache and fever. However, in addition to these common treatments, three less well-known uses for local cold compresses are described in U.S. Patents Nos. 2,438,643, 3,175,558, and 4,552,149.

[0008] U.S. Patent No. 2,438,643 discloses a pack for use in local cooling anesthesia, which includes a plurality of waterproof compartments containing saline and an absorbent material such as sawdust. The pack can be cooled by any suitable cooling device and then used as a local cold pack. Since the pack needs to be stored frozen, its use for inducing local hypothermia is limited to locations where frozen storage is possible.

[0009] Also, U.S. Patent No. 4,552,149 discloses a refrigerant-dependent cold pack containing a coolant, which is more specifically a head cooling device. The device includes a body consisting of a cooling piece covering the top of the head and a plurality of cooling pieces radially arranged around the body to cover the front, sides, and rear of the head. This head cooling cap is designed to suppress hair loss during the administration of drugs or chemotherapeutic agents for which hair loss is a known side effect. Like all cooling packs that require freezing, the head cooling device is most suitable for hospital and home use and is not very suitable for use in pre-hospital emergency treatments where conventional (electric) refrigeration is not generally available.

[0010] U.S. Patent No. 3,175,558 discloses a heat treatment pack designed especially for post-delivery application to a female perineum, which contains unreacted components of an endothermic reaction. The unreacted components are isolated by a frangible barrier, a sustained release capsule, or both, and the isolation is maintained until the cold pack is needed. In use, the reactants are mixed, for example, by manually breaking a weak barrier between them, to initiate the endothermic reaction and reduce the overall temperature of the cold pack and its contents. The pack is placed on the patient as needed, and the application area is cooled by reverse conduction heating of the pack by the body.

[0011] In some prior art devices, cooling of the fluid within the device is achieved by an endothermic reaction between water and ammonium nitrate, which typically exist as a single population of pellets. The amount and form of the reactants are generally selected to produce a fluid that does not drop below the freezing point in order to prevent the tissue from freezing and being damaged. Although tissue damage is avoided, in such situations the cooling of the patient is not optimal.

[0012] As described above, prior art patents and techniques for local cooling have only defects that prevent their effective use in emergency treatment of in-field cardiac arrest or severe shock. The inventions disclosed in U.S. Patent No. 4,750,493 and U.S. Patent No. 4,920,963 addressed and overcame some of these drawbacks early on by providing sufficient head cooling to the extent that whole-body cooling can be performed more effectively than can be achieved by a local cooling pack. Even so, the devices disclosed therein were relatively bulky, with a preferred dimension of 2'×2'×2'. Coupled with a significant typical weight (about 25 pounds), needless to say, these devices had inherent limitations with respect to the ability to apply external cooling to produce deep internal hypothermia with optimal precision and accuracy, and were limited with respect to the area in which they could be stored and deployed.

[0013] Accordingly, in the medical community, there remains an unmet need for a portable device with a limited physical profile that enables the induction of controlled hypothermia for the cooling of the cranial and extracranial regions. Additionally, there is still a need to rapidly and deeply cool patients, particularly brain tissue, while simultaneously avoiding tissue damage due to freezing. Presumably, such emergency methods and systems will require trained use by those with emergency medical expertise, but at a minimum, the system would most preferably be simple, easily deployable, and easily monitored even away from the "field" and hospital environments.

Summary of the Invention

[0014] To meet this unmet need, the present invention relates to directly injecting into the left ventricle of the heart of a patient or animal a sufficient amount of cooled saline or cryoprotective solution to generate a cooling blood flow through two carotid arteries, two vertebral arteries, and the brain to cool the brain, typically using a 14- to 18-gauge cannula with a retractable trocar in a cardiac arrest or initial cardiac arrest state. Since the injection of the cooled saline or cryoprotective solution prevents restarting of the heart, the present invention also includes the use of VA ECMO as described above for an animal or patient as a well-established heart / lung bypass device, which provides support for both respiration and hemodynamics and can be used not only in the field but also in any medical setting. Any respiration and hemodynamic support equivalent to VA ECMO may be used instead of VA ECMO. Typically, a sufficient amount of saline or cryoprotective solution is injected under a pressure high enough to produce 30% of the baseline total carotid blood flow (in contrast to CPR, which typically produces only 10% of the same blood flow), and for an average height and weight patient, it is usually 1 to 2 liters and in fact does not exceed 2 liters. A cannula mechanism with a retractable trocar with an adjustable sharp tip for directly and selectively puncturing the left ventricle of the heart through the skin, along with a surrounding flexible rigid shield and stopcock, provides a sterile self-sealing system suitable for use in the "field" or hospital environment and, in combination with VA ECMO or a simpler electric or manual pump, performs continuous or pulsatile liquid injection.

Brief Description of the Drawings

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Figure 1A

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Figure 1B

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Figure 2

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Figure 3A

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Figure 3B

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Figure 3C

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Figure 3D

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Figure 3E

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Figure 3F

[0024] As described immediately above, the present invention relates to injecting a sufficient amount of cooled saline or cryoprotectant directly into the left ventricle of the heart using a 14 to 18 gauge catheter or its equivalent, creating a flow of cooled blood into the brain through both the carotid and vertebral arteries to cool the brain. A longer and continuous infusion of the cooled saline or cryoprotectant can create a more systemic hypothermia when needed, such as during resuscitation for cardiac arrest or severe shock. Systemic hypothermia is generally appropriate for a limited time to improve the adverse effects of stroke. Since the injection of the cooled saline or cryoprotectant prevents the restart of the heart due to the low temperature, the present invention includes the use of VA ECMO (or its equivalent), as well as a portable heart / lung bypass device that can provide support for both respiration and hemodynamics and can be used not only in a medical setting but also at the scene, which is well-established (known in the art). Any respiratory and hemodynamic support device or protocol equivalent to VA ECMO may be substituted in relation to the inventive concept described herein. In contrast to CPR, which typically produces only 10 to 20% of the total carotid blood flow, sufficient saline or cryoprotectant is injected under a pressure high enough to produce 30% of the baseline total carotid blood flow. As will be described in detail below, a cannula mechanism with a retractable trocar with an adjustable sharp tip for selectively puncturing directly through the skin into the left ventricle of the heart provides a sterile self-sealing system suitable for use "in the field" or in a hospital environment, along with a surrounding shield and stopcock.

[0025] Direct left ventricular puncture is optimal as an injection site for cold saline for the following reasons. When using the left ventricle, only one puncture is required to perfuse the entire cerebrovascular system. The left ventricle is thick and will typically seal automatically even if a small diameter puncture such as a trocar / 14 to 18 gauge cannula occurs or remains. Even if leakage occurs, if the aortic valve is functioning during VA ECMO, bleeding will be limited and rapid transfusion and perfusion will continue by VA ECMO. Optionally, percutaneous closure may be possible as needed by using an optional guidewire embodiment (see FIGS. 1, Modules F, G, and H). In a cardiac arrest scenario, the left ventricle is easy to find. In contrast, individual arteries are smaller, more difficult to position and manipulate in a cardiac arrest situation, more difficult to cannulate than the left ventricle, do not seal as easily as the left ventricle, and typically have plaque. This plaque can be accidentally bumped and released, causing fatal embolization. For these reasons, attempts to cannulate a blood vessel rather than the left ventricle are not acceptable for injecting the cooling fluid. By injecting at high pressure into the left ventricle, additional flow can be entrained via the Venturi effect that creates a high pressure flow. Given the thick walls of the left ventricle, these high injection pressures are better tolerated than any thin walled blood vessel. Thus, injection and infusion of the cooling fluid into the left ventricle, rather than other veins or arteries, is preferred in the context of this technology. The fluid itself may be cold saline, cold protective fluid, or any cold solution suitable for injection into the circulatory system of an animal or patient in need of cooling.

[0026] More specifically, cerebral and systemic hypothermia can be achieved rapidly and easily using the following techniques and hardware. Typically, percutaneous left ventricular cannulation with a small-diameter cannula (14 to 18 gauge) fitted with a retractable trocar for initial dissection and puncture can rapidly induce a protective / therapeutic hypothermic state during cardiac arrest by injecting cold cardiocerebroplegia fluid into the left ventricle at high pressure. Pilot studies have shown that this technique can achieve 30% of baseline cerebral blood flow in a short period of time (Figure 2). Therefore, the brain is rapidly cooled. Some people speculate that a similar effect can be obtained by inserting a cannula into the carotid artery, but as mentioned above, this is much more technically difficult than intracardiac injection, requires insertion into both carotid arteries, and also requires inserting the cannula into a smaller target, which has a risk of disrupting atherosclerotic plaques and is likely to cause a stroke in the patient. When fluid is introduced into the left ventricle, a forward flow is generated by increasing the pressure in the left ventricle, closing the mitral valve and opening the aortic valve. By using a high-pressure jet, blood in the circulatory system is taken in, thereby increasing the effective volume of the perfusion fluid. A left ventricular assist device (LVAD) is transplanted into the left ventricle through an open surgery to supplement cardiac output semi-permanently / permanently. In contrast, the device of the present invention is designed as a temporary means for achieving brain and organ protection, and it is highly likely that CPR will resume after the injection is completed. The infusion that can be injected in this way is only a limited amount (generally 2 liters or less). This is because there is no recirculation of the fluid back to the pump, and volume overload will occur in the patient if it continues indefinitely. Due to the decrease in the temperature of the brain and body, the CPR blood flow is insufficient during normothermia but sufficient to preserve tissues, especially vulnerable brain substances. By utilizing pulsatile flow (described further below), more of the patient's own blood fills the jets in the left ventricle, thereby increasing the volume of the perfusion fluid and enabling perfusion at a more effective level than general CPR. The cold cardiocerebroplegia fluid is kept at a relatively low temperature because more of the patient's own blood needs to be cooled by each jet.

[0027] As will be described in more detail below in connection with the figures, in contrast to a more simple percutaneous intravascular device, a stiff, perhaps metallic, trocar / cannula insertion device is required to penetrate the left ventricle. This is because a strong piercing mechanism is required to transverse all of the tissue layers that need to be penetrated, including the wall of the left ventricle, in order to access the left ventricular cavity. By using a stronger and stiffer cannula, kinking and crimping during and after insertion are prevented. (More flexible and less robust cannulas are more susceptible to post-insertion movement and "catheter whip" which can be harmful to the left ventricle.) The stiff cannula also enables better direction of the jet towards the left ventricular outflow tract / aortic valve. Also, cannulas with a small diameter are known to often be removable from the left ventricle without the need for surgical procedures to close the ventricular insertion tract. The patient is typically placed on VA ECMO, and since perfusion from the VA ECMO device ascends the aorta from the opposite direction, the aortic valve prevents blood loss from the continuously open tract within the left ventricle until spontaneous circulation is restored. Since a preserved state of the brain and the body is thought to be achieved, there is no concern about restarting the heart immediately at the scene. This is because clinical data in cases of accidental hypothermia shows that the limits of CPR in the absence of brain injury can be extended to several hours. In one emulation, Figure 1A (see Modules F - G - H), a guidewire may be inserted into the path extending from the puncture site into the left ventricle. By fixing the wire, a commercially available plug member can be passed over the wire to occlude the left ventricular path as needed. Additionally, if the cannula needs to be reinserted, it can be passed over this wire. The outer components are composed of a pre-treated sheath with malleability, and the unique folded / folding accordion-style wire can prevent loss of the wire within the tubing. To maintain sterility, the outer segment of the wire may be covered with a simple sterile dressing.

[0028] The device of the present invention also has a plurality of features for verifying optimal positioning. When an ultrasonic device is available, if the clinician is skilled in using ultrasound, the optimal position can be confirmed by this means. In order to enable confirmation of the cannula position, the trocar needs to be configured to enable aspiration of blood from the left ventricle after the left ventricle has been punctured. This will ensure proper placement in the event that cannula insertion is performed "blindly", i.e., without ultrasound or other imaging guidance. A typical trocar has a solid structure, but the trocar of the present invention is hollow or has a side channel attached that allows blood flow, as will be described in more detail below (however, the trocar must be solid at its cutting tip). The need for solidity at the cutting tip of the trocar is that if the trocar is configured like a stylet of an IV catheter (essentially a hollow trocar) with a hollow center at the tip, the cutting tip can cause coring of the punctured tissue. This coring can subsequently cause embolization after the injection has started. Also, if the tip of the trocar is completely hollow, it can also interfere when trying to aspirate blood from the left ventricle to confirm the current cannula position. Thus, several embodiments of the cutting shape (such as a "pencil tip" or hexagon) for the trocar of the present invention are contemplated. All of these require a solid or predominantly solid sharp trocar tip of various geometric shapes, but the central portion of the trocar (not the tip itself) will be hollow starting from an "eye of the bird" near the cutting tip. The eye of the bird forms a conduit through which fluid (including blood) can be "pulled back" to convince the operator that the trocar / eye of the bird / cannula is actually properly positioned within the left ventricle. When using ultrasound, the determined positioning can be further verified or optimized by visualizing the flow generated within the left ventricle.As further described in connection with the figures, rather than completely removing the trocar after the initial placement, the trocar is retracted within a sealed system and blood / body fluid is drawn through the eye of the needle to establish the position of the left ventricle, such that the trocar can be reinserted without causing external contamination or accidental air introduction and the position of the cannula can be reconfirmed by "aspiration". Additionally, rather than including a hollow center, the trocar can beneficially be grooved on the outside in a manner that allows aspiration from the left ventricle, such that when the trocar is in a predetermined position within the cannula into which it fits snugly, the groove effectively forms a hollow passageway. For practical reasons, mainly due to the narrow gauge of the trocar, it is generally easier and stronger to construct a grooved trocar than a hollow trocar. Such a grooved trocar may be applied to other medical fields where it is desired to sample or further inject fluid before the cannula or catheter is placed and the trocar removed. The grooved trocar can also be used when an obturator is used in the insertion technique, i.e., when the obturator is basically a trocar with a rounded tip. In particular, since removal and obturator replacement are repeatedly necessary to determine whether the tip of the cannula is within the ventricular space of the brain, the insertion of an intracerebral ventricular catheter can be an application of the grooved trocar of the present invention. Constructed and as described below, the trocar can be withdrawn when the cannula has been successfully placed within the left ventricle and is housed within the sterile area of the device of the present invention, and the needle is covered to protect against accidental needlesticks by the patient, operator, or bystander. If it is desired to completely remove the trocar from the device, this too is an option, taking into account the placement of the stopcock through which the trocar passes. The transparent covering member will readily tear away from the aforementioned stopcock. The diaphragm into which the tip of the trocar is first inserted may be made of a self-sealing polymer and should be so. An additional port (D) (see FIG. 1A) is present and allows repeated aspiration, if desired, for the purpose of reconfirming the cannula position during the injection process.

[0029] The device optimally consists of a completely sealed percutaneous transmyocardial cannula / trocar device for use in association with a heart-brain perfusion reservoir / pump (Figs. 1, reference numerals A - E, I, and J), and an optional Seldinger-type wire function (Figs. 1, reference numerals F, G, and H) for marking the insertion path within the left ventricle. All of these features are further disclosed and described in relation to the accompanying drawings.

[0030] Referring now to Fig. 1, module A includes the main cannula 10 of the present invention. It is shown in module B and is inserted using a specially designed trocar designed to be used with the main cannula 10. The main cannula 10 is in the 14 - 18 gauge or equivalent catheter size range. The main cannula is connected to the cannula adapter 12 via the cannula adapter connector 14. The cannula adapter connector is typically a threaded male / female connector, but can be any connector (snap-in, press-fit, etc.) that can equally maintain a fluid-sealed sterile system. Adjacent to the cannula adapter connector 14 is the distal stopcock 16. The distal stopcock 16 is directly connected to the distal stopcock rigid housing 18, which is a hollow tube connected to the stopcock at the distal end of the tube, whereas the proximal end of the hollow tube is completely covered by the rigid housing diaphragm 20 (the housing is rigid, while the diaphragm 20 itself is flexible and typically has self-sealing permeability). The rigid housing diaphragm 20 is formed of a flexible elastic polymer that can be breached (punctured) by the trocar of the present invention but optimally self-seals when the trocar is withdrawn. As shown in Fig. 1A, the trocar 22 has already been pushed through the rigid housing diaphragm 20, and the trocar cutting tip 24 is shown in a position immediately proximal to the distal stopcock 16. Here, the trocar cutting tip 24 is completely covered and cannot prick the operator, patient, or bystander.

[0031] Regarding FIG. 1A, it should be understood that the trocar base 26, the trocar 22, and the trocar cutting tip 24 (all showing a long continuous structure) that are linearly connected are much longer than shown in FIG. 1A and are therefore the broken part of the figure in Module B. The trocar 22, when passing through the main cannula 10, needs to be long enough to extend out from the distal tip 11 of the cannula and function as a cutting edge to traverse the patient's tissue starting from the chest skin to a position within the left ventricle of the heart. After positioning the main cannula 10 in relation to the trocar 22, the trocar 22 can be retracted to the position shown in FIG. 1A, where it does not interfere but remains contained within a sterile closed environment as further described below.

[0032] Sterilization (pre-sterilization) of the pre-assembled structure of FIG. 1A, particularly the main cannula 10 and its associated structures shown in segments A and B, is mainly performed by the flexible sheath 29 in some cases. The flexible sheath 29 may be made of any flexible polymer material and is generally much longer than that shown in FIG. 1A, perhaps 4 to 12 inches or more, up to about 20 to 24 or 30 inches at most. The flexible sheath 29 allows the trocar 22 to pass through the main cannula 10 and exit from the cannula distal tip 11 because there is sufficient slack in the flexible sheath to allow this. Further, the trocar can be retracted without affecting the closed environment within the flexible sheath 29. As shown in FIG. 1A, the flexible sheath 29 extends around and encloses the region between the distal end of the distal stopcock rigid housing and the proximal stopcock in a sterile field (created by means known in the art), but the flexible sheath may actually only extend from the proximal end of the distal stopcock rigid housing to the trocar connector 28 as long as the interior of the flexible sheath is maintained sealed without tears (other than the tear introduced into the diaphragm 20 by the cut end of the trocar 22 itself). In this way, when the trocar 22 needs to be inserted into the patient, then retracted, and then re-inserted into the patient, the sterile field at the insertion site is maintained at all times, especially when selectively closing the distal stopcock 16 as needed.

[0033] The trocar base 26 is firmly fixed to the trocar connector 28 in FIG. 1A, but when the distal stopcock 16 is in the open position, the trocar 22 can freely pass forward (distally) and backward (proximally) through the main cannula 10 anywhere along the length of the trocar 22.

[0034] The flow of fluid into the main cannula 10 is ultimately introduced through a fluid syringe 32, or its functional or structural equivalent (manual pump, hand pump, or other fluid injection device). While the main cannula 10 is in a predetermined position, the proximal stop cock 30 is maintained in a closed position. When initiating cryogenic fluid injection, the proximal stop cock needs to be manually opened and maintained in an open state while the fluid is introduced into the system.

[0035] During the placement of the main cannula 10, especially in the field, where there is no ultrasonic guidance for placing the trocar cutting tip 24 and the main cannula 10 in the left ventricle of the patient being treated, a method is needed to confirm that the cannula is properly placed. (Of course, ultrasonic examination or fluoroscopic guidance may be used to place the main cannula 10, but in the field, such guidance may not be available). One way to confirm the correct placement of the cannula distal tip 11 is to open the suction stopcock 40 and "pull back" the suction syringe 36 to confirm that there is a return of blood (and associated left ventricular blood supply) from the cannula tip 11 located at a predetermined position within the left ventricle. This return occurs most readily while the trocar is still in the position where it was first inserted, and blood can be drawn through the bird's eye 35 into the trocar 22 and then into the suction syringe 36, where the return of blood can be seen. Of course, even after retraction of the trocar, it is possible to confirm that blood returns from the cannula tip 11 to the suction syringe 36. The advantage of the suction syringe 36 is that it provides a simple and mechanical confirmation that the cannula distal tip 11 is actually in the correct position within the cavity of the left ventricle of the heart. Of course, the suction syringe 36 has the suction cannula 38 attached thereto, and the suction cannula 38 is interconnected to the suction stopcock 40. After the trocar 22 is first placed within the patient, the cannula distal tip 11 is then within the left ventricle, and the only stopcock that is initially in the open position within the system is the suction stopcock 40, which enables the user to "pull" to confirm the return of blood. Once the return of blood is confirmed, the suction stopcock 40 is closed and both the distal stopcock 16 and the proximal stopcock 30 are opened to allow cold fluid to enter the main cannula 10 from the fluid syringe 32 and then into the left ventricle of the patient (possibly assisted by the reservoir of module C and the pump connected thereto).

[0036] The optional feature shown in FIG. 1A is module F-G-H, which provides a Seldinger wire for placement assistance. The Seldinger wire is known in the art but has not been used in a system such as the present invention. If it is desired to withdraw the entire main cannula 10 (not just trocar 22) and later reinsert the cannula, the Seldinger wire can be inserted along the cannula into the left ventricle to maintain the insertion path. The Seldinger wire has a flexible detachable flange that allows it to advance through the infusion cannula. When it exits the tip of the infusion cannula, the flange spreads to prevent the wire from becoming lost within the patient. That is, the deployed structure shown in module G holds the wire in a fixed position within the patient, so the wire cannot be inadvertently withdrawn or slip out. This option of module G allows for the reinsertion of another catheter or cannula other than the first cannula, if desired, or facilitates the introduction of a left ventricular wall closure device as desired or necessary.

[0037] Referring again to the trocar 22, with the trocar 22 fully inserted into the patient, the tip of the trocar (the trocar cutting tip 24 thereof is depicted in the loading (extended) position in the module of symbol I) is used and the chest wall is punctured in an orientation optimized to enter the left ventricle well. As described above, the trocar is a special hollow or grooved trocar and has at least one bird's eye hole, so the trocar is not hollow (or grooved) up to the distal tip. After confirming that the cannula / trocar is thought to be in the left ventricle, the proximal stopcock 30 is opened and the trocar is flushed with ultrasound in Doppler mode (if available) to verify positioning and good flushing in the left ventricle. When using fluoroscopy, the IV contrast agent is contained in the flush syringe, or in the case of Doppler, it is saline. As described above, the aspiration syringe 36 can be used to draw blood for confirmation when fluoroscopy or Doppler guidance is not available. This is because it is possible to blindly insert into the left ventricle (albeit not optimally) using only anatomical landmarks. The main cannula 10 is preferably made of steel like the trocar 22, but equivalent materials can be substituted. Considering that a plurality of tough tissue layers need to be penetrated by the trocar / cannula device, an "accordion" does not occur in a steel cannula, while an "accordion" may occur in a plastic cannula. A plastic cannula with sufficient strength can include a marking material for ultrasonic inspection or fluoroscopy as needed, but steel is easier to observe by ultrasonic inspection or fluoroscopic observation. After the cannula / trocar is considered to be in the appropriate position in the left ventricle, the cannula may be attached to the skin by the attachment device of symbol J, and the device also preserves the sterility of the puncture site. If it is expected that the cannula will be removed immediately or promptly after the first jet perfusion, the module J is not necessarily required. Thereafter, the trocar is withdrawn to the length limited by the flexible sheath 29.If deemed necessary, the trocar 22 can be completely removed from the system by tearing the flexible sheath 29 and closing the illustrated stopcock to prevent air leakage into the system.

[0038] When ready to initiate jet perfusion, the proximal stopcock 30 can be turned on for a final position confirmation and additional flushing. Close the proximal stopcock 30 and open the module C - heart - brain perfusion reservoir and pump (including stopcock 46), and cold heart - brain perfusion solution is injected under high pressure, perhaps or usually (but not necessarily) by a power pump, a mechanical pump, or a manual pump. In other words, fluid pumping can be achieved by an electric motor or, in the case of on - site use modalities, by any manual mode of pumping (Figure 1A, module C). The reservoir requires a capacity of approximately 2 liters. The flexible sheath 29 with the trocar 22 retracted prevents air from entering the system by the Venturi effect, especially when the distal stopcock 16 is closed after jet perfusion has started.

[0039] As described above for one part, modules G and H are optional modifications like module F and exhibit additional features for a standard guide wire contained within a transparent airtight wrapper. If one desires to remove the cannula while holding the guide wire in place, the guide wire is advanced in a standard manner and the attached flange G will prevent the proximal tip of the guide wire from dropping out within the cannula device module A. When the cannula device module A is removed, the wire can be manually secured at the skin puncture site on the distal side of the currently retracted cannula. To completely remove the cannula, the flange G will be removed from the specially designed proximal module H of the guide wire. This allows the guide wire to be passed through the cannula module A, and as a result, the jet perfusion device can be completely removed from the site. To prevent loss of the guide wire within the patient, the proximal portion of the guide wire is typically specially configured of a malleable material with "memory" to have proposed optional bend points within the proximal guide wire. These multiple bend points, once bent, prevent the guide wire from being lost within the patient through the puncture site or otherwise being easily retrieved.

[0040] A sterilization band may be placed over the outside of the guide wire to maintain sterility. This guide wire arrangement serves several purposes. First, if one desires to reinsert the perfusion cannula, this guide wire can be used to do so. The bend points can be straightened and the catheter can be passed over the guide wire and returned to its proper position. Additionally, puncture of the left ventricle can result in persistent bleeding at the puncture site. A percutaneous insert of a puncture sealing device such as used for non-invasive VSD closure can be passed over such a guide wire and used to non-surgically close the leaking puncture site.

[0041] The figure of Figure 1A shows a fully closed system for left ventricular high-pressure "jet" injection of "cerebral perfusion" solution, which is mainly targeted at the brain, but is also beneficial when other organs are kept in a stopped state mainly as a bridge to VA ECMO. The figure shows the components of a fully embodied device. This is a closed system because if air can enter the left ventricle at any time, it can cause air embolisms in vital organs, especially the coronary arteries / heart and brain, resulting in devastating consequences. The device of the present invention is also a closed system with high injection pressure resistance to prevent disengagement during high-pressure injection that causes leakage of the injected fluid and potential air entry into the left ventricle. The system is also closed to maintain sterility. The attached data (Figure 2) shows that when pressure injecting into the left ventricle through a 16- to 18-gauge catheter (used in the test) in an animal model, blood flow to the brain improves and rapid cerebral perfusion becomes practical. In rapid heart-brain perfusion, the heart is rapidly cooled by injection into the left ventricle, so not only the brain but also other organs, especially the heart, are protected. As described above, the heart is much more easily accessible than trying to inject through the individual arteries supplying the brain. Also, as described above, a person in a critical condition is likely to have atherosclerotic disease, and when pricked with a needle, fragments from the plaque may flow into the brain from upstream, causing irreparable damage. Four arteries, the right common carotid artery, the left common carotid artery, the left vertebral artery, and the right vertebral artery, supply blood to the brain. When injecting into the left ventricle, all four arteries are involved in the perfusion of the brain with cerebral perfusion fluid. In addition, it is known that small-diameter punctures of the left ventricle are overwhelmingly highly self-sealing. By using a small-diameter puncture device, the possibility of tissue damage due to an incomplete insertion technique is minimized. The use of high-pressure injection helps to perfuse vital organs by entraining the blood present in the cardiovascular system. By using extremely cold injection fluid, the resulting mixed blood and injection fluid reach a low temperature of the treatment temperature after mixing.

[0042] Referring back to FIG. 1, module A is an infusion cannula, module B is a trocar, module C is an infusion reservoir and an infusion pump device, and module D is a cannula position confirmation device. Module E is a wire insertion module, module F is a sterile trocar retraction module, module G is a trocar position verification module, and module H provides the aforementioned optional guide wire hardware. As is clear from the above, the cannula device of the present invention is percutaneously inserted into the left ventricle through the left chest or upper abdomen with the trocar fully extended into the infusion cannula. Since the trocar is a hollow trocar with a tip the size of a bird, once the tip enters the vascular structure, if the trocar is in the correct position, blood will return through the eye of the bird by suction with the syringe depicted in module G.

[0043] The following simplified overview summarizes all of the above. The syringe will be partially filled with either a commonly used intravenous solution such as normal saline or a cardioplegia solution (such as those known in the art for open heart surgery). In the context of the present invention, a "cerebral cardioplegia solution" is any solution that includes but is not limited to prior art cardioplegia solutions, can be cooled, and is suitable for introduction into the circulatory system of animals and patients in need of the hypothermia treatment of the present invention. By using ultrasound in Doppler mode, the flow generated by injecting into the hollow trocar can be detected along with the flow exiting the left ventricle through the bird's eye, thereby verifying a good position within the left ventricle. The tip of the injection cannula and trocar may also be constructed of special echogenic materials that can be used additionally or alternatively to confirm the position of the injection cannula and trocar within the left ventricle. The continuous trocar retraction module is constructed of transparent plastic to visualize the process, and the specified length also allows the tip of the trocar to remain within the unused portion of the injection cannula system without exiting the system and causing the potential for puncture problems even when fully retracted. It is also a safety feature for the healthcare provider. By maintaining sterility, the trocar can be reinserted into the injection cannula as needed to reposition the cannula. Both the trocar and the injection cannula are rigid solid metal structures. This better tolerates high-pressure injection and reduces catheter whip. Since plastic catheters are known to be sheared by such devices, the trocar cannot be safely reintroduced. The tip of the trocar is not hollow so that no tissue core is created within the trocar and it is not inadvertently blocked during any injection procedure. Once the catheter position is confirmed within the left ventricle and the retracted trocar, injection under high pressure can be initiated. Thereafter, various solutions may be injected according to current data and practice, and such fluids should also be cooled. Module C is an injection reservoir and injection device. Various means for cooling the solution are used and may be appropriately insulated to maintain the cooling.An electric infusion pump may be used, an air pressure device such as in high-pressure intravenous infusion may be used, or a mechanical piston device may be further incorporated. Further, if it is desired to confirm the position of the infusion cannula after trocar insertion, blood can be aspirated using Module D, or a solution can be infused and the position of the cannula can be confirmed with a Doppler. Module G is a wire guide that is inserted into the left ventricle down the cannula and maintains the insertion path when it is desired to withdraw all of the infusion cannula. The wire has a flexible detachable flange that allows it to advance through the infusion cannula. When it exits the tip of the infusion cannula, the plunger spreads to prevent the wire from becoming lost within the patient. This option allows for the reinsertion of another catheter or cannula by the Seldinger technique upon removal of the flange, or facilitates the introduction of a left ventricular wall closure device upon straightening of the "accordioned" outer portion of the wire.

[0044] Next, referring to FIG. 1B, an alternative embodiment of the trocar 22 has a trocar base 26 attached to the inner plunger portion of the trocar syringe 27, such that the trocar is extended and retracted via the trocar syringe 27 rather than necessarily relying on the adaptive force of the flexible sheath 29. The trocar 22, as in FIG. 1A, passes through the distal stop cock 16 (in the open position) and likewise through the hollow center of the cannula fitting connector 14 and extends from there through the cannula distal tip (not shown) to the cannula distal tip.

[0045] For both the shape of the cutting tip and whether the channel connecting near the trocar tip is the hollow inner tube within the trocar or the groove within the trocar that forms a hollow fluid tube within the cooperating cannula, FIGS. 3A - 3F show various embodiments of the trocar in combination with an adjacent cannula. In all of these figures, the trocar / cannula combination 300 has a trocar 322, an associated cannula 324 through which the trocar 322 can travel in either direction, a trocar cutting tip 326, and either a trocar hollow center 330 or a trocar groove 332. FIGS. 3A and 3B include a bird's eye opening 328. All of their structures and their functions have been described above.

[0046] It is possible to inject fluid into the system at a constant flow rate, but the preferred injection of cryogenic fluid is pulsatile injection, such as 60 to 100 pulses per minute. This pulsatile injection can be done manually or using a manually or computer - controlled electric or other pump (see Module C in FIG. 1A). When pulsatile flow is introduced, approximately 30 to 50% of the pulsatile time will be actual fluid injection, and a balance of "recovery" will be achieved. Thus, for a pulsatile flow injection of 60 pulses per minute, approximately 0.3 to 0.5 seconds will be fluid injection, and the rest will be the recovery period, during which the left ventricle will contract and refill or otherwise equilibrate. Pulsatile flow promotes cooling by more quickly mixing the cold fluid with the flow of body fluids within the patient, while a non - interrupted direct flow is thought to promote less mixing.

[0047] Although the present invention has been described in detail, the present invention should be limited only as defined in the appended claims.

Claims

1. A percutaneous transmyocardial jet perfusion device, comprising: A trocar and cannula device that cooperate to perforate and cannulate the left ventricle of the heart of a patient or animal in need of treatment; A fluid reservoir filled with a certain amount of fluid introduced into the left ventricle of the heart; A fluid syringe filled with a certain amount of fluid introduced into the left ventricle of the heart; A flexible sheath; And comprising: The main cannula of the cannula device is connected to a first stopcock via a joint; The first stopcock is connected to one end of a rigid hollow tube, and the other end of the rigid hollow tube is covered with a diaphragm formed of an elastic polymer having flexibility; The base of the trocar is in fluid communication with the fluid syringe via a tube provided with a second stopcock; The flexible sheath is disposed between the first stopcock and the second stopcock so as to surround the rigid hollow tube; The trocar extends within the flexible sheath, penetrates the diaphragm, and is inserted into the rigid hollow tube; The fluid reservoir is in fluid communication with the main cannula via a tube provided with a third stopcock, a percutaneous transmyocardial jet perfusion device.

2. The device according to claim 1, wherein the trocar has a solid cutting tip.

3. The device according to claim 2, wherein the trocar has both a solid cutting tip and a bird's-eye opening adjacent to the solid cutting tip.

4. The device according to claim 3, wherein the bird's-eye opening is connected to a hollow tube within the trocar.

5. The device according to claim 3, wherein the bird's-eye opening is connected to a groove of the trocar, and the groove cooperates with the cannula device to form a fluid channel.

6. The device according to claim 3, wherein the trocar can be retracted outside the rigid hollow tube.

7. The device according to claim 3, further comprising a Seldinger wire that can be inserted into the left ventricle of the heart along the cannula device to maintain the insertion path of the cannula device into the left ventricle of the heart.

8. The device according to claim 3, further comprising a suction syringe that suctions blood from the left ventricle of the heart via a suction cannula that selectively communicates with the cannula device. Claim 9 The device according to claim 3, comprising a pump used to send fluid from the fluid reservoir to the left ventricle of the heart via the cannula device. Claim 10 The device according to claim 9, wherein the pump is a manual pump. Claim 11 The device according to claim 9, wherein the pump is an electric pump. Claim 12 The device according to claim 9, wherein the pump is configured to provide a pulsatile fluid flow. Claim 13 The device according to claim 9, wherein the pump is configured to provide a pulsatile fluid flow of 60 to 100 pulses per minute. Claim 14 The device according to claim 9, wherein the pump is configured to provide a pulsatile fluid flow, and the pulses generated by the pump have a duty cycle in which 30 to 50% of the period of the pulsatile flow represents active pumping.

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