Patent Application
20090270806
The present invention relates generally to medical devices and methods, and more particularly to devices and methods for controlling the depth at which diagnostic or therapeutic substance(s) is/are injected into a tissue mass or organ of a human or animal subject.
In medicine and surgery, there are numerous occasions wherein it is desirable to limit the depth to which a needle or other elongate penetrator penetrates into an organ or tissue mass. In this regard, various devices have been used to limit the depth to which needles and other devices penetrate. For example, U.S. Pat. No. 5,141,496 describes a syringe guide with adjustment of the depth to which the needle penetrates. One end of the syringe guide has a sliding base which is adjustable by means of a screw and the other end includes a spring-loaded sliding portion that is affixed to the syringe and propels the needle to a predetermined depth of injection.
U.S. Pat. No. 5,250,026 (Ehrlich et al.) describes an implant injector that has an adjustable insertion depth feature. The insertion depth adjusted by moving the nose of the injector relative to the tip of the cannula that extends past the nose. In addition to adjusting the insertion depth, the cannula or needle, may also be rotated to a plurality of positions relative to the injector handle. A spring loaded plunger, when released by a release button, will push the implant out the end of the cannula as the operator withdraws the cannula from the animal. The release button is designed as a safety trigger to avoid premature activation of the plunger during insertion of the needle. Needles, or cannulas of various diameters and lengths, may be interchanged in the injector. Also, the spring loaded plunger for expelling the implant may be removed allowing the operator to replace the plunger with a different diameter and length plunger, if desired, to match different size cannulas.
U.S. Pat. No. 5,102,393 (Sarnoff et al.) describes an autoinjector that has an intramuscular injection mode and a subcutaneous injection mode. An injection mode converting structure is useable to convert the device back and forth between a subcutaneous mode wherein the needle is allows to advance to a first depth that does not extend substantially beyond subcutaneous tissue at the injection site and an intramuscular mode wherein the needle is allowed to advance to a second depth that is within muscle that underlies the subcutaneous tissue.
U.S. Pat. No. 3,538,916 describes an injection pistol for intramuscular implantation of encapsulated liquid or solid chemical material. The depth of injection of the needle is controlled by an injection depth gauge mounted on the injection needle. A shaft having a slidable plunger integral therewith is mounted on the frame and is utilized to eject the material from the needle after the needle has been advanced into the muscle. The travel of the plunger within the injection needle is limited by a threadedly adjustable depth stop mounted on the end of the shaft opposite the plunger.
U.S. Pat. No. 4,270,537 (Romaine) describes a hypodermic syringe and automatic needle insertion device wherein the syringe is biased against a trigger when the needle is in the retracted position. Upon release of the trigger, the syringe and needle are driven forward extending the needle into the underlying tissue. The depth of insertion may be predetermined by the attachment of an interchangeable stop.
It is particularly important to limit the depth of injection when drugs, cells (e.g., myoblasts) or other substances are being injected into the myocardium of the heart. In such procedures, if the injector is advanced to far it may go all the way through the myocardial wall and into a chamber of the heart. If the substance is then inadvertently injected into a chamber of the heart rather than into the myocardial wall, the intended therapeutic benefit of injection into the myocardial tissue will be lost and potentially serious complications may result from the inadvertent introduction of the substance into the patient's bloodstream. One such procedure currently under development is the injection of platelet gel (PG) into an infarcted area of myocardium to improve myocardial function and/or to prevent deleterious ventricular remodeling following myocardial infarction or other injury to the myocardium. In this therapy, a platelet-containing component (e.g., platelet rich plasma (PRP)) is combined with a thrombin-containing component (e.g, a thrombin solution) immediately before, during or after injection into the myocardium at one or more location(s) within or near an infarct or other myocardial injury. The platelet-containing component (e.g., PRP) combines with the thrombin-containing component and forms a platelet gel (PG) which causes the desired therapeutic effect. Such PG is formed when components (such as fibrinogen) contained in the platelet-containing component are activated by thrombin contained in the thrombin-containing component. Autologous PRP can be obtained from the subject's own blood, thereby significantly reducing the risk of adverse reactions or infection. When autologous PRP is used as the platelet-containing component, the resultant PG is referred to as autologous platelet gel (APG). The addition of thrombin to platelet-containing plasma products such as PRP is described in detail in U.S. Pat. No. 6,444,228 and United States Patent Application Publication Nos. 2007/0014784, 2006/0041242 and 2005/209564, the disclosures of each such patent and patent application being expressly incorporated herein by reference. Since it is difficult to pass PG or APG through the lumen of a needle, it is desirable to inject the platelet-containing component and the thrombin-containing component such that they become mixed immediately prior to, during or after injection through the needle. Additionally, injecting the platelet-containing component and the thrombin-containing component separately or immediately after mixing may allow the infusate to distribute to a greater area before fully gelling into the PG or APG, thereby possibly enhancing the effect of this therapy. Multiple component injectors that are suitable for delivery of PG therapy into myocardial tissue and include optional depth stops for limiting the depth to which the injector penetrates into the myocardium are described in U.S. patent application Ser. No. 11/969,094, the disclosure of which is also expressly incorporated herein by reference.
There remains a need for the development of new devices and methods for controlling or limiting the depth to which an injector or other elongate penetrator penetrates into an organ or tissue mass.
The present invention provides new devices and methods for controlling the depth to which a penetrator penetrates into an organ or tissue mass. As used herein the terms “angular injection” and “angular entry” indicate an injection, or the entry of a needle or penetrator, wherein the needle enters the injection site at an angle that is not perpendicular or orthogonal to the surface being penetrated by the needle. Thus, for an angular injection or angular entry to occur, the needle would not enter the injection site at a right angle to an imaginary plane that is tangent to the surface at the point of injection.
In accordance with one embodiment of the invention, there is provided a device for controlling the depth to which an elongate penetrator penetrates into an organ or other tissue mass, such device comprising; a first member comprising a penetrator shroud having a hollow bore extending therethrough and a distal end and a second member to which the penetrator is attached. The penetrator extends distally from the second member. The second member is engageable with the first member such that the penetrator extends through the bore of the penetrator shroud. The distance to which the penetrator extends beyond the distal end of the penetrator shroud is adjustable. The penetrator is then advanceable into the organ or tissue mass only until the distal end of the shroud abuts against the surface of the organ or tissue mass, thereby limiting the depth to which the penetrator can penetrate. Optionally, the distal end of the penetrator shroud may be beveled to a desired angle relative to the longitudinal axis of the penetrator to allow angular injections. The penetrator may have one or more lumens to permit aspiration or infusion or substances after it has been inserted to the desired depth of penetration.
Further in accordance with the invention, in some embodiments, the penetrator may have at least two coaxial lumens and may be used for simultaneous injection of two component substances such that the component substances become combined in situ to form a combination product. For example, a platelet rich plasma (PRP) containing component may be infused through one lumen and a thrombin containing component may be infused through another lumen such that the platelets and thrombin will combine to form platelet gel (PG) at the site of injection within the organ or tissue. In some instances, at least the PRP can be produced from a recipeint's own blood and the resulting PG will be an autologous platelet gel (APG). The site of injection may be within or near an area of impaired myocardial function and the PG or APG may have the effect of improving myocardial function and/or preventing ventricular remodeling.
Further or alternative elements, aspects, objects and advantages of the present invention will be understood by those of skill in the art upon studying of the accompanying drawings and reading of the detailed description and examples set forth below.
The following detailed description, the accompanying drawings are intended to describe some, but not necessarily all, examples or embodiments of the invention. The contents of this detailed description and accompanying drawings do not limit the scope of the invention in any way.
A penetrator 18 extends in the distal direction from the proximal member 14. An elongate body 20 surrounds a proximal portion of the penetrator 18. A series of vertical slots 22 are formed in one side of the elongate body 20. A flat surface 24 is formed on top of the elongate body 20. Off-center locking members 26 extend vertically through one side of the bore 17 of the first member 12. The elongate body is sized such that, when it is rotated 90 degrees such that its flat surface 24 is on the same side as the locking members 26, the flat surface 24 will pass by the locking members 26, thereby allowing the distal portion of the penetrator 18 and the elongate body 20 to be freely advanced into the bore 17 of the first member 12. Thereafter, when the proximal member 14 is rotated back to a position wherein the flat surface 24 is in top of the elongate body 20, the locking members 26 will seat within certain ones of the slots 22, thereby joining the first member 12 to the proximal member 14 such that a fixed distance D exists between the first member 12 and proximal member 14. When desired, the proximal member 14 may again be rotated 90 degrees such that the flat surface 24 of the elongate body 20 is on the same side as the locking members 26 and the proximal member may be retracted or advanced to a new position with the flat surface 24 passing by the locking members 26. After reaching the new position, the proximal member 14 may be rotated 90 degrees back to its previous rotational orientation, causing locking members 26 to seat in different ones of the slots 22. In that manner the distance D between the proximal and first members 12, 14 and the extent to which the penetrator extends beyond the distal end DE of the shroud 16 may be adjusted. Optionally, the distal end DE of the shroud 16 may be cut on an angle or bevel as shown, thereby controlling the angle or trajectory on which the penetrator 18 will advance through the tissue. In one embodiment, the angle A between the needle and the face of the distal end of the shroud is 30 degrees.
Optionally, horizontally extending wings 28a, 28b may be formed on the proximal member 14 and horizontally extending wings 30a, 30b may be formed on the first member 12 to facilitate ease of grasping and manipulating the proximal member 14 and first member 12.
The particular example of the device 10 shown in the drawings is designed for injection of 2 components. Thus, the penetrator 18 has a first lumen 32 and a second lumen 34 extending therethrough. A first component tube 38 is connectable to the proximal member 14 to infuse a first component through the first lumen 32 of the penetrator 18 and a second component tube 36 is connectable to the proximal member 14 to infuse a second component through the second lumen 34 of the penetrator 18.
Based on pre-procedure imaging studies, the wall thickness of the myocardium in the area of the infarct is known, as is the specific location of the infarcted tissue into which it is desired to deliver the injection. On that basis, the physician will determine the desired depth of injection (i.e., the distance between the epicardial surface of the heart and the center of the infarct zone). The desired depth of injection will necessarily be less than the full thickness of the myocardial wall on the intended needle trajectory, thereby avoiding the possibility of inadvertent injection of the treatment materials into the ventricle. As seen in
As shown in
Thereafter, with the penetrator 18 so positioned, the PRP and thrombin solution will be simultaneously injected through the coaxial lumens 32, 34 and out of the end of the penetrator 18 causing mixing of the PRP and Thrombin Solution and resultant in situ formation of a quantity of PG within the infarct zone as described in detail in the above-incorporated U.S. patent application Ser. No. 11/969,094. In at least some embodiments, the PRP and thrombin solution may be delivered at a ratio of about 10 parts PRP to 1 part thrombin solution. In embodiments where flexible supply tubes 36, 38 or other flexible member(s) is/are attached to the device 10, allow an operator to insert the penetrator into a heart for an angular injection while allowing the device 10 to be sufficiently free to undergo some movement along with natural myocardial motions of the beating heart. Because the device is not rigidly connected to any syringes or other infusion apparatus, the infusion apparatus does not undergo any movement caused by the motion of the heart. This provides a clinician with better control of the injection because the infusion apparatus can be manipulated separately from the injection device.
After the therapeutic substances have been injected, the device 10 may be removed and the procedure shown in
Those of skill in the art will appreciate that potential uses of this embodiment of the device 10 having the penetrator 18 with coaxial lumens 32, 34, are not limited to delivery of PG therapy to the myocardium but may be used to deliver virtually any two-component therapy or diagnostic material to any organ, tissue mass, cavity, lumen or other target location. Other examples of two-component materials that may be delivered using this device 10 include, but are not limited to, two component tissue adhesives and sealants (e.g., Tisseel VH™ Fibrin Sealant, available commercially from Baxter Healthcare Corporation, Deerfield, Ill.) and tissue bulking agents, fillers or polymeric materials (e.g., hydrogels) that may be fomred or expanded in situ for various therapeutic or cosmetic applications such as tissue bulking, filling or expanding and various prodrug+activator combinations.
Also, the devices of the present invention need not be used only for two component delivery. Instead, the penetrator 18 may have a single lumen for delivery of a single material or any number of additional lumens (3 or more) for delivery of multiple component therapies having more than two components.
Also, the particular configuration and construction of the device 10 shown in
Another alternative configuration and construction is seen in the device 10b of
Another alternative configuration and construction is seen in the device 10c of
It is to be further appreciated that the invention has been described hereabove with reference to certain examples or embodiments of the invention but that various additions, deletions, alterations and modifications may be made to those examples and embodiments without departing from the intended spirit and scope of the invention. For example, any element or attribute of one embodiment or example may be incorporated into or used with another embodiment or example, unless to do so would render the embodiment or example unsuitable for its intended use. Also, where the steps of a method or process are described, listed or claimed in a particular order, such steps may be performed in any other order unless to do so would render the embodiment or example not novel, obvious to a person of ordinary skill in the relevant art or unsuitable for its intended use. All reasonable additions, deletions, modifications and alterations are to be considered equivalents of the described examples and embodiments and are to be included within the scope of the following claims.
