Vascular incisor and method

Abstract

An improved vascular incisor and method for allowing a user to safely create an incision in a body lumen. The present invention provides an apparatus which can create an incision in a front wall of the ascending aorta while preventing the blade from creating an incision in surrounding body structures, such as the back wall of the ascending aorta. The incisor includes a surgical element such as a blade which is activated by an actuator. As the actuator is depressed, the blade is moved from a protected, retracted position to an exposed, deployed position. The exposed blade is pushed into a front wall of the ascending aorta to create an incision. As the actuator is depressed further, the blade is automatically moved to the retracted position to prevent the blade from incising the back wall of the aorta.

What is claimed is:  
     
         1 . An apparatus for creating a vascular incision comprising: 
 a body;    a rod movable relative to the body and having a proximal end and a distal end:    a surgical element disposed at the distal end of the rod, wherein the rod and surgical element are movable between a retracted position and a deployed position, wherein the rod and surgical element are biased in the retracted position;    an actuator coupled to at least one finger which engages the proximal end of the rod, wherein activation of the actuator advances the surgical element from the retracted position to the deployed position; and    a ramp on the body to engage the finger as the rod and surgical element move to the deployed position, wherein the ramp disengages the finger from the proximal end of the rod to allow the surgical element to move to the retracted position.    
     
     
         2 . The apparatus of  claim 1  further comprising a return spring, wherein the actuator is movable between an undepressed position and a depressed position, wherein the return spring biases the actuator to the undepressed position.  
     
     
         3 . The apparatus of  claim 2  wherein the actuator defines a longitudinal axis and the rod defines a longitudinal axis, wherein the longitudinal axis of the actuator is substantially aligned with the longitudinal axis of the rod.  
     
     
         4 . The apparatus of  claim 1  wherein the actuator is coupled to multiple fingers which engage the rod.  
     
     
         5 . The apparatus of  claim 1  wherein the proximal end of the rod comprises an enlarged push rod cap.  
     
     
         6 . The apparatus of  claim 5  wherein the finger comprises a protrusion which engages the push rod cap.  
     
     
         7 . The apparatus of  claim 1  wherein the actuator is adapted to be engaged by a user's thumb or palm.  
     
     
         8 . The apparatus of  claim 1  wherein the body comprises finger grips adapted to be held by the user's fingers.  
     
     
         9 . The apparatus of  claim 1  wherein the finger disengages from the rod when the rod and surgical element have been advanced to a fully deployed position.  
     
     
         10 . The apparatus of  claim 1  wherein the finger is flexible and is resiliently biased radially inward towards the proximal end of the rod.  
     
     
         11 . The apparatus of  claim 1  wherein the disengagement of the finger from the rod creates an audible click.  
     
     
         12 . The apparatus of  claim 1  wherein the ramp forces the finger radially outward away from the proximal end of the rod.  
     
     
         13 . The apparatus of  claim 1  wherein the surgical element is a blade.  
     
     
         14 . The apparatus of  claim 13  wherein the blade has a width between approximately 4 mm and 6 mm.  
     
     
         15 . The apparatus of  claim 13  wherein a leading edge of the blade has two outwardly facing edges.  
     
     
         16 . The apparatus of  claim 13  wherein the rod is advanced at a 1:1 rate with the actuator.  
     
     
         17 . The apparatus of  claim 1  further comprising an elongate housing which extends distally from the body to encase the rod and surgical element.  
     
     
         18 . The apparatus of  claim 17  wherein the elongate housing and rod are flexible.  
     
     
         19 . The apparatus of  claim 17  wherein the elongate housing comprises a tapered distal tip having an opening to allow the surgical element to move between the retracted position and the deployed position.  
     
     
         20 . The apparatus of  claim 17  further comprising a cannula removably coupled to the elongate housing, the rod extending through the cannula.  
     
     
         21 . The apparatus of  claim 20  wherein the cannula comprises a keying element to align the cannula in a predetermined orientation relative to the surgical element.  
     
     
         22 . The apparatus of  claim 21  wherein the combination of the body, rod, surgical element, actuator, ramp, and rod spring are lighter than the cannula.  
     
     
         23 . An automatically retracting incisor comprising: 
 a housing;    a push rod having a proximal end and a distal end, wherein the push rod is movable between a retracted position and a deployed position, the push rod coupled to the housing and biased toward the retracted position;    a surgical element disposed at the distal end of the push rod;    a trigger pin releasably engaging the proximal end of the push rod; and    a ramp on the housing engaging the trigger pin, wherein movement of the trigger pin moves the push rod and the surgical element from the retracted position towards the deployed position such that the trigger pin slides along the ramp, wherein the trigger pin reaches a top of the ramp and the trigger pin disengages from the push rod to allow the surgical element and push rod to return to the retracted position.    
     
     
         24 . The automatically retracting incisor of  claim 23  wherein the trigger pin is coupled to an actuator, wherein the actuator is movable between an initial position and an actuated position.  
     
     
         25 . The automatically retracting incisor of  claim 24  wherein the actuator comprises two handles.  
     
     
         26 . The automatically retracting incisor of  claim 25  wherein the handles are pivotally coupled to the body.  
     
     
         27 . The automatically retracting incisor of  claim 26  wherein the handles in the initial position are outwardly separated from the body and the handles in the actuated position are adjacent to the body.  
     
     
         28 . The automatically retracting incisor of  claim 27  wherein the handles in the actuated position move the surgical element to the deployed position.  
     
     
         29 . The automatically retracting incisor of  claim 27  wherein the handles are biased towards the initial position.  
     
     
         30 . The automatically retracting incisor of  claim 24  wherein the push rod defines a longitudinal axis and the actuator defines a longitudinal axis of motion, wherein the longitudinal axis of motion of the actuator is parallel to the longitudinal axis of the push rod.  
     
     
         31 . The automatically retracting incisor of  claim 24  wherein the actuated position is distal of the initial position.  
     
     
         32 . The automatically retracting incisor of  claim 24  wherein the actuator comprises a thumb switch slidably coupled to the body.  
     
     
         33 . The automatically retracting incisor of  claim 24  wherein the actuator is biased to the initial position.  
     
     
         34 . The automatically retracting incisor of  claim 23  wherein the trigger pin is removably received in an aperture in the push rod.  
     
     
         35 . The automatically retracting incisor of  claim 34  wherein the trigger pin is biased into the aperture and is urged out of the aperture by the ramp.  
     
     
         36 . The automatically retracting incisor of  claim 23  wherein the surgical element is a blade.  
     
     
         37 . The automatically retracting incisor of  claim 23  wherein movement of the surgical element from the deployed position to the retracted position makes an audible sound.  
     
     
         38  The automatically retracting incisor of  claim 23  wherein the push rod and surgical element are encased by an elongate housing, the elongate housing being attached to the body.  
     
     
         39 . An incisor comprising: 
 a body;    an elongate rod coupled to the body, the elongate rod comprising a proximal end and a distal end;    a surgical element positioned at the distal end of the rod, wherein the surgical element and rod are movable between a retracted position and a deployed position, the rod and surgical element being biased to the retracted position:    a hammer positioned in the body;    a hammer spring in engagement with the hammer;    an actuator coupled to a cam having a surface which engages the hammer, wherein movement of the actuator from an initial position to an actuated position moves the hammer to compress the hammer spring, wherein the cam disengages from the hammer, to allow the hammer spring to expand and push the hammer distally against the push rod so as to move the surgical element to the deployed position.    
     
     
         40 . The incisor of  claim 39  further comprising a actuator spring which biases the actuator in the initial position.  
     
     
         41 . The incisor of  claim 39  wherein the surgical element and rod are biased to the retracted position by a rod spring, the rod spring immediately biasing the surgical element and rod from the deployed position to the retracted position.  
     
     
         42 . The incisor of  claim 39  wherein the hammer is decoupled from the elongate rod.  
     
     
         43 . A method of deploying and retracting a surgical element, the method comprising: 
 depressing a plunger substantially along a longitudinal axis of the device to move the surgical element from a retracted position to a deployed position; and    moving the surgical element from the deployed position to the retracted position independently of further movement of the plunger.    
     
     
         44 . The method of  claim 43  further comprising biasing the plunger to an undepressed position.  
     
     
         45 . The method of  claim 43  comprising informing the user that the surgical element has been retracted.  
     
     
         46 . The method of  claim 45  wherein the informing step is carried out by making an audible click.  
     
     
         47 . The method of  claim 43  further comprising positioning the surgical element through a cannula.  
     
     
         48 . The method of  claim 43  wherein an incision in the tissue structure is created during the depressing step.  
     
     
         49 . The method of  claim 48  comprising advancing a cannula through the incision before removing the surgical element from the incision.  
     
     
         50 . The method of  claim 49  wherein the plunger is depressed in the same direction as the cannula is advanced.  
     
     
         51 . The method of  claim 49  wherein the depressing step and the advancing step are carried out substantially simultaneously.  
     
     
         52 . The method of  claim 43  further comprising releasing the plunger to move the plunger from a depressed position to an undepressed position.  
     
     
         53 . The method of  claim 43  wherein the moving step is carried out by disengaging the plunger from a rod attached to the surgical element.  
     
     
         54 . The method of  claim 43  wherein the surgical element is a blade.  
     
     
         55 . A method of inserting a cannula into a blood vessel comprising: 
 positioning an incisor adjacent the blood vessel;    activating an actuator to move a surgical element from a retracted position to a deployed position to create an incision in the blood vessel wall; and    automatically moving the surgical element from the deployed position to the retracted position while simultaneously inserting the cannula into the blood vessel.    
     
     
         56 . The method of  claim 55  further comprising maintaining the position of the incisor within the cannula during the moving step.  
     
     
         57 . The method of  claim 55  further comprising automatically returning the actuator to an initial position.  
     
     
         58 . The method of  claim 55  wherein the actuator is coupled to the surgical element through a rod, wherein the moving step is carried out by biasing the rod to the retracted position.  
     
     
         59 . The method of  claim 55  wherein the actuator is advanced distally to move the surgical element to the retracted position.  
     
     
         60 . The method of  claim 55  wherein the cannula is inserted in the same direction as the actuator is advanced.  
     
     
         61 . The method of  claim 55  wherein the activating step is carried out by squeezing two handles together.  
     
     
         62 . A method of creating an incision comprising: 
 placing a distal tip of a device adjacent a vessel wall;    activating an actuator to compress a spring;    expanding the spring to deploy a surgical instrument to create an incision in the vessel wall; and    automatically retracting the surgical element.    
     
     
         63 . The method of  claim 62  wherein the expanding step is performed independently of further activating of the actuator.  
     
     
         64 . The method of  claim 62  wherein during the activating step the actuator engages a protrusion on a hammer with a cam surface.  
     
     
         65 . The method of  claim 64  wherein the expanding step is carried out by moving the cam surface beyond the protrusion on the hammer such that the hammer is released and the spring moves the hammer to deploy the surgical element.  
     
     
         66 . The method of  claim 62  further comprising biasing the actuator to an initial position, wherein the actuator in the initial position is ready for repeat actuation.  
     
     
         67 . An assembly for creating an incision in a blood vessel, the assembly comprising: 
 a cannula having a lumen;    an incisor having an automatically retracting surgical element, the incisor being removably receivable within the lumen of the cannula, the incisor comprising: 
 a body;  
 a push rod coupled to the surgical element, the push rod and surgical element being movable relative to the body between a retracted position and a deployed position, wherein the push rod and surgical element are biased in the retracted position;  
 an actuator coupled to the push rod, the actuator facilitates the movement of the push rod and surgical element from the retracted position to the deployed position;  
 a fixed release mechanism positioned on the body, wherein movement of the actuator to a first position moves the push rod and surgical element from the retracted position to the deployed position so as to create an incision in the blood vessel, wherein activation of the actuator to a second position causes the fixed release mechanism to disengage the push rod from the actuator and allow the push rod and surgical element to be biased back to the retracted position.  
   
     
     
         68 . The assembly of  claim 67  wherein the actuator is biased back to an initial position.  
     
     
         69 . The assembly of  claim 67  wherein the actuator comprises handles pivotally connected to the body, wherein the handles in the first position are outwardly separated from the body and the handles in the second position are adjacent to the body.  
     
     
         70 . The assembly of  claim 67  wherein the incisor comprises finger grips adapted to be held by a user's fingers.  
     
     
         71 . The assembly of  claim 67  wherein the actuator comprises a thumb switch.  
     
     
         72 . The assembly of  claim 67  wherein the actuator is coupled to the push rod with at least one flexible finger.  
     
     
         73 . The assembly of  claim 67  wherein a trigger pin on the actuator releasably engages an aperture on the proximal end of the push rod  
     
     
         74 . An assembly for creating an incision in a blood vessel, the assembly comprising: 
 a cannula having a lumen;    an incisor having an automatically retracting surgical element, the incisor being removably receivable within the lumen of the cannula, the incisor comprising: 
 a body;  
 a rod having the surgical element at a distal end, wherein the surgical element and rod are movable between a retracted position and a deployed position, the rod and surgical element being biased to the retracted position;  
 a hammer coupled to the body;  
 a hammer spring in engagement with the hammer;  
 a movable cam having a surface which engages the hammer, wherein movement of the cam surface from an initial position to an actuated position moves the hammer to compress the hammer spring, wherein disengagement of the cam surface from the hammer causes the hammer spring to expand and push the hammer distally against the rod to move the surgical element to the deployed position.  
   
     
     
         75 . A method of occluding an aorta comprising: 
 deploying a surgical element to create an opening in the aorta;    automatically retracting the surgical element;    inserting the cannula through the opening and into the aorta;    withdrawing the surgical element from the cannula; and    positioning an aortic occlusion device in at least a portion of the aorta.    
     
     
         76 . The method of  claim 75  wherein the retracting step and inserting step are performed substantially simultaneously.  
     
     
         77 . The method of  claim 75  wherein the surgical element is moved from the retracted position to the deployed position through activation of an actuator.  
     
     
         78 . The method of  claim 77  wherein the retracting step is carried out independently of further activation of the actuator.  
     
     
         79 . The method of  claim 75  wherein the cannula is inserted into the aorta before removing the surgical element from the incision.  
     
     
         80 . The method of  claim 75  further comprising expanding an occluding member to occlude aorta.  
     
     
         81 . An assembly for treating the ascending aorta comprising: 
 a cannula having a lumen;    an incisor having an automatically retracting surgical element, the incisor being removably received in the lumen of the cannula, wherein the surgical element is positioned near a distal end of the cannula to create an incision in the ascending aorta; and    an aortic occlusion device insertable through the lumen of the cannula and into the incision in the ascending aorta after the incisor has been removed from the cannula.    
     
     
         82 . The assembly of  claim 81  wherein the cannula and incisor are simultaneously inserted through the incision.  
     
     
         83 . The assembly of  claim 82  wherein the aortic occlusion device comprises at least one lumen and an occluding member.  
     
     
         84 . The assembly of  claim 83  wherein the occluding member comprises a balloon.  
     
     
         85 . The assembly of  claim 81  wherein the surgical element is attached to a push rod, wherein an actuator facilitates movement of the push rod and surgical element from a retracted position and a deployed position.