Abstract:
An apparatus to puncture a blood vessel has an elongate body portion having a first end, a second end, and a lumen. A pusher member is received by the lumen and a gentle flow tip is coupled to the second end. A blade is in communication with the pusher member, wherein the blade is positioned around the outer curvature of the gentle flow tip.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority based on U.S. Patent Provisional Application Ser. No. 60/623,289, entitled “Cannula With Incision Blade” by Stephen B. Colvin, Alan Katz, Dr. Eugene Grossi and Aubrey C. Galloway, filed on Oct. 29, 2004. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to medial devices. More specifically, the present invention relates to cannulas with an incision blade. 
     BACKGROUND OF THE INVENTION 
     Cannulae are devices which connect items of hardware or drainage vessels to a patient&#39;s body. During heart surgery, for example, a patient&#39;s blood is oxygenated and circulated by an artificial heart lung machine. A surgical incision is made into the patient&#39;s aorta wherein a cannula is surgically secured such that the outlet end is directed into and along the route of the aorta. 
     With conventional cannulaes, there have been flow problems associated with the relatively high velocity of blood into the aorta. There are also concerns over the possible dislodgement of fatty tissue from the vicinity of the aorta and its potentially serious implications. Specifically, there is concern that blood emerging at high velocity from cannulae could damage the aortic wall and/or dislodge atheromatous plaque and hence cause embolic phenomena. Additionally, another concern is that high velocities (and related high impact pressures) might disturb the distribution of flow to the blood vessels. 
     Atheromatous plaque can be released into the general blood circulation when there is cannulation of the aorta, manipulation of the heart and ascending aorta, and application or release of the cross-clamp or side biting clamp to the aorta. Furthermore, boluses of air or “surgical air” can enter the general blood circulation when there is cannulation of the heart or aorta and removal of the cross clamp, at the site of venous cannulation and when a surgical intervention requires the opening of the cardiac chambers. As such, the use of alternative cannulas such as the “soft flow” cannula or “dispersion” cannula have been popular. These cannulas are designed to not have a central flow through a central orifice to avoid having a high velocity jet of blood hitting the back side of the blood vessel wall. However, the velocity of the blood flow from current “soft flow” cannulas are still high, at about 4-6 liters per minute. The gentle flow cannula of the present invention is able to descrease the blood flow even further. 
     In any type of surgery, especially cardiac surgery, time is of the essence. The less time it takes a surgeon to perform the surgery the better. Currently, incisions are first made into a blood vessel with a surgical knife. The surgical knife is then removed and the cannula is inserted into the incision. The time to perform these two procedures may be drastically reduced by the present invention. 
     BRIEF DESCRIPTION OF THE INVENTION 
     An apparatus to puncture a blood vessel has an elongate body portion having a first end, a second end, and a lumen. A pusher member is received by the lumen and a gentle flow tip is coupled to the second end. A blade is in communication with the pusher member, wherein the blade is positioned around the outer curvature of the gentle flow tip. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated into and constitute a part of this specification, illustrate one or more embodiments of the present invention and, together with the detailed description, serve to explain the principles and implementations of the invention. 
       In the drawings: 
         FIGS. 1A-1D  illustrate a gentle flow arterial dispersion cannula with an incision blade in accordance with an embodiment of the present invention. 
         FIGS. 2A ,  2 B,  2 C illustrate the gentle flow arterial dispersion cannula with an incision blade in use with a blood vessel in accordance with an embodiment of the present invention. 
         FIGS. 3A and 3B  illustrate the gentle flow tip in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present invention are described herein in the context of a cannula with an incision blade. Those of ordinary skill in the art will realize that the following detailed description of the present invention is illustrative only and is not intended to be in any way limiting. Other embodiments of the present invention will readily suggest themselves to such skilled persons having the benefit of this disclosure. Reference will now be made in detail to implementations of the present invention as illustrated in the accompanying drawings. The same reference indicators will be used throughout the drawings and the following detailed description to refer to the same or like parts. 
     In the interest of clarity, not all of the routine features of the implementations described herein are shown and described. It will, of course, be appreciated that in the development of any such actual implementation, numerous implementation-specific decisions must be made in order to achieve the developer&#39;s specific goals, such as compliance with application- and business-related constraints, and that these specific goals will vary from one implementation to another and from one developer to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking of engineering for those of ordinary skill in the art having the benefit of this disclosure 
     The present invention relates to medical devices such as a cannula with an incision blade for piercing a blood vessel. The present invention may be used for various procedures such as ophthalmology surgery, orthopedic surgery, cardiac surgery, and other procedures that require the puncture of a blood vessel. Thus, the examples described in the present application with reference to cardiac surgery is exemplary and not meant to be limiting. Additionally, the surgical knife may be used with any type of cannula. The example described in the present application with reference to the use of a gentle flow arterial dispersion cannula is exemplary and not intended to be limiting. As such, the incision blade may be used with a traditional cannula, dispersion cannula, and the like. 
       FIGS. 1A-1D  illustrate a gentle flow arterial dispersion cannula with an incision blade in accordance with an embodiment of the present invention. Referring to  FIGS. 1A and 1B , the device, generally numbered  100 , has a blade pusher  102  in communication with the blade  104  via a blade extension  116 . The blade pusher  102  is inserted into the handle  108  of elongated hollow body portion  106  at a first end  110 . A gentle flow tip  112  may be positioned at the second end  114  of the body portion  106 . 
     The blade  104  is positioned such that it is integral with the outer curvature of the device  100  and not on the inside of the device  100 . Positioning the blade  104  on the outer curvature of the device  100  rather than through the center or lumen of the device  100  prevents a central flow of blood through the device to avoid the high velocity jet of blood hitting the blood vessel wall. The blade  104  may surround the entire outer curvature of the gentle flow tip  112 , however, it is generally not desirable since it will block the blood flow from exiting the gentle flow tip  112 . As illustrated in  FIG. 1B , the blade  104  surrounds about one-half or less of the entire outer curvature of the gentle flow tip  112 . 
     The blade  104  is connected to the blade pusher  102  through blade extension  116  which is held in position along the outer curvature of the device  100  with holder members  118   a ,  118   b ,  118   n  (where n is an integer). Blade extension  116  is connected to blade pusher  102  within the hollow tube of handle  108 . At first end  110 , the blade extension  116  exits the hollow tube and is positioned on the exterior outer curvature of device  100 . 
     The holder members  118   a ,  118   b ,  118   n  each have an aperture (not shown) to securely, but loosely, hold the blade extension  116  in place along the outer curvature of the device  100 . Holder members  118   a ,  118   b ,  118   n , although illustrated as projections on the exterior of the device  100 , may also surround the circumference of the device  100  similar to stopper member  120 . Stopper member  120  may have an aperture  122  to securely, but loosely position the blade extension  116 . Additionally, stopper member  120  has a diameter greater than the diameter of the gentle flow tip  112 . 
     As illustrated in  FIGS. 1C and 1D , when the blade pusher  102  is pushed in the direction of arrow A, the blade extension  116  is also pushed in the same direction, which causes blade  104  to be pushed in the direction of arrow B. The holder members  118   a ,  118   b ,  118   n  and stopper member  120  loosely, but securely, hold the blade extension  116  in position such that it is movable within the members when the blade pusher  102  is pushed. As further illustrated in  FIG. 1D , a front view of the gentle flow tip  112  and blade  104 , the blade  104  is positioned along the outer curvature of the gentle flow tip  112 . 
       FIGS. 2A ,  2 B, and  2 C illustrate the gentle flow arterial dispersion cannula with an incision blade in use with a blood vessel in accordance with an embodiment of the present invention. As illustrated in  FIG. 2A , the device  200  may be placed at the position on the blood vessel  202  where the incision is to be made. Once the desired position is achieved, the user pushes on the blade pusher  102 , which causes the blade  204  to puncture the blood vessel  202  at  FIG. 2B . Once the blade  204  has punctured the blood vessel  202 , the user may insert the gentle flow tip  208  into the blood vessel  202  until stopper member  206  prevents the device  200  from further entering the blood vessel lumen  210  at  FIG. 2C . Simultaneously, the user releases the blade pusher  102 , which causes the blade  204  to retract to its original position. The gentle flow tip  208  is entirely positioned within the blood vessel lumen  210 . The user is able to perform this procedure in one single step rather than in the multiple steps currently required. 
       FIGS. 3A and 3B  illustrate the gentle flow tip in accordance with an embodiment of the present invention.  FIG. 3B  is a cross sectional view of  FIG. 3A . The gentle flow tip, generally numbered  300 , has a lumen  302  and a plurality of apertures  304  on the outer curvature of the gentle flow tip  300 . The gentle flow tip  300  has an enclosed bottom end  306  and an inverted solid cone  308  within the lumen  302  at the bottom end  306 . The inverted solid cone  308  causes the blood to flow outwardly perpendicular to the gentle flow tip  300  and thus parallel the blood vessel lumen  210  (as illustrated in  FIG. 2C ). This prevents the blood flow exiting the gentle flow tip  300  from damaging the blood vessel wall and/or dislodging any atheromateous plaque which may cause embolic phenomena. 
     While embodiments and applications of this invention have been shown and described, it would be apparent to those skilled in the art having the benefit of this disclosure that many more modifications than mentioned above are possible without departing from the inventive concepts herein. The invention, therefore, is not to be restricted except in the spirit of the appended claims.