Bone Marrow Access Device

Abstract

A bone marrow access device includes a cannula and a sharp stylet removably positioned in the cannula. The cannula defines a distal opening at a distal tip and a side aperture in a side of the cannula, proximally from the distal opening. The stylet has a sharp distal tip and extends beyond the distal opening. A plug is receivable in the cannula distal to the side aperture to seal the distal opening when the stylet is removed. A method of accessing bone includes inserting the cannula and sharp stylet positioned in the cannula into bone; removing the sharp stylet from the cannula; pushing a plug through the cannula and distal to the side aperture to seal the distal opening of the cannula; and accessing the bone through the side aperture. Accessing the bone can include aspirating bone marrow, injecting a substance, or inserting an instrument into the bone.

1 .- 24 . (canceled) 
     
     
         25 . A method to seal a flexible portion of an outer cannula of an aspiration device, the aspiration device including a handle at a proximal end of the outer cannula, the outer cannula including a solid wall tip at a distal end of the cannula, the flexible portion including cuts in a wall of the outer cannula, the method comprising:
 placing an inner tube in the outer cannula, the inner tube spanning the flexible portion of the outer cannula;   with a distal end of the inner tube, engaging the tip at the distal end of the outer cannula, the inner tube and outer cannula forming an air tight seal distal to the flexible portion of the outer cannula; and   with a proximal end of the inner tube, engaging the outer cannula or a luer connector at the handle, the inner tube forming an air tight seal proximal to the flexible portion, the inner tube and outer cannula defining an aspiration channel that is sealed against air leaking through the cuts of the flexible portion.   
     
     
         26 . The method of  claim 25 , wherein the flexible portion comprises a laser cut tube. 
     
     
         27 . The method of  claim 25 , wherein the inner tube engages the distal tip of the outer cannula in an interference fit. 
     
     
         28 . The method of  claim 25 , wherein the outer cannula includes a tapered inner surface near the distal tip, the inner tube engaging the outer cannula at the tapered inner surface. 
     
     
         29 . The method of  claim 25 , wherein the outer cannula defines a side aperture in a side of the cannula and a distal opening at a distal tip of the cannula, and wherein the inner tube has a closed distal end to seal the distal opening. 
     
     
         30 . The method of  claim 29 , wherein the inner tube is an aspiration cannula that includes a side opening to align with the side aperture of the outer cannula. 
     
     
         31 . The method of  claim 30 , wherein the aspiration cannula includes an outer jacket, and wherein engaging the distal tip of the outer cannula includes causing the outer jacket to become lodged against an inner surface of the distal tip. 
     
     
         32 . The method of  claim 31 , wherein the aspiration cannula is flexible. 
     
     
         33 . The method of  claim 29 , wherein the inner tube is an elongated cap-shaped plug. 
     
     
         34 . The method of  claim 33 , further comprising pushing the cap-shaped plug through the outer cannula and distal to the side aperture to seal the distal opening of the cannula. 
     
     
         35 . The method of  claim 25 , wherein the aspiration device includes a sharp stylet positioned in the outer cannula, the stylet having a sharp distal tip that extends through a distal opening of the cannula, and further comprising removing the sharp stylet from the cannula and inserting a blunt stylet into the cannula, the blunt and sharp stylets differing in stiffness. 
     
     
         36 . A bone marrow aspiration device, comprising:
 an outer cannula defining a distal opening at a distal tip of the cannula and a side aperture in a side of the cannula and positioned proximally from the distal opening, the outer cannula including a flexible portion that includes cuts in a wall of the outer cannula;   a handle on a proximal end of the outer cannula; and   an inner tube receivable in the outer cannula, the inner tube spanning the flexible portion of the outer cannula, a distal end of the inner tube engaging the tip at the distal end of the outer cannula, the inner tube and outer cannula forming an air tight seal distal to the flexible portion and side aperture of the outer cannula, a proximal end of the inner tube being coupled to a luer connector at the handle, the inner tube and luer connector forming an air tight seal proximal to the flexible portion, the inner tube and outer cannula defining an aspiration channel that is sealed against air leaking through the cuts of the flexible portion.   
     
     
         37 . The device of  claim 36 , wherein the flexible portion comprises a laser cut tube. 
     
     
         38 . The device of  claim 36 , further comprising a sharp stylet removably positioned in the cannula, the stylet having a sharp distal tip and extending beyond the distal opening of the outer cannula. 
     
     
         39 . The device of  claim 38 , further comprising a blunt stylet having a blunt distal tip, the blunt stylet receivable in the outer cannula when the sharp stylet is removed, the blunt and sharp stylets differing in stiffness. 
     
     
         40 . The device of  claim 36 , wherein the outer cannula includes a tapered internal surface near the distal tip of the outer cannula, and wherein the inner tube is configured to securely lodge against the tapered internal surface and distal to the side aperture of the outer cannula. 
     
     
         41 . The device of  claim 40 , wherein an outer dimension of the inner tube is less than an inner diameter of the outer cannula proximal to the tapered internal surface and greater than an inner diameter of the outer cannula at the tapered internal surface. 
     
     
         42 . The device of  claim 36 , wherein the inner tube has a closed distal end to seal the distal opening of the outer cannula. 
     
     
         43 . The device of  claim 42 , wherein the inner tube is an aspiration cannula that includes a side opening to align with the side aperture of the outer cannula. 
     
     
         44 . The device of  claim 43 , wherein the aspiration cannula includes an outer jacket, and wherein engaging the outer cannula includes causing the outer jacket to become lodged against an inner surface of the distal tip. 
     
     
         45 . The device of  claim 36 , wherein the inner tube is an elongated cap-shaped plug. 
     
     
         46 . The device of  claim 45 , further comprising a push rod receivable in the outer cannula to deploy the cap-shaped plug into the outer cannula to seal the distal opening. 
     
     
         47 . The device of  claim 36 , further comprising an adjustable depth guide to move the cannula when the cannula is positioned within bone, the depth guide including a lead screw attached to the cannula handle and a threaded jacket receivable on the lead screw. 
     
     
         48 . A method of aspirating bone marrow, comprising:
 inserting an outer cannula into bone, the outer cannula defining a distal opening at a distal tip of the outer cannula and a side aperture in a side of the cannula and positioned proximally from the distal opening, the outer cannula including a flexible portion that includes cuts in a wall of the outer cannula;   placing an inner tube in the outer cannula, the inner tube spanning the flexible portion of the outer cannula, a distal end of the inner tube engaging the distal tip of the outer cannula, the inner tube and outer cannula forming an air tight seal distal to the flexible portion and sider aperture of the outer cannula, a proximal end of the inner tube coupled to a luer connector of a handle at a proximal end of the outer cannula, the inner tube and luer connector forming an air tight seal proximal to the flexible portion, the inner tube and outer cannula defining an aspiration channel that is sealed against air leaking through the cuts of the flexible portion; and   aspirating bone marrow through the side aperture of the outer cannula.   
     
     
         49 . The method of  claim 48 , wherein inserting the outer cannula into bone includes inserting the outer cannula and a sharp stylet positioned in the cannula into bone, the stylet having a sharp distal tip that extends through the distal opening, and further comprising removing the sharp stylet from the outer cannula before aspirating the bone marrow. 
     
     
         50 . The method of  claim 49 , further comprising inserting a blunt stylet into the outer cannula when the sharp stylet is removed, the blunt and sharp stylets differing in stiffness, and inserting the outer cannula and blunt stylet further into bone. 
     
     
         51 . The method of  claim 48 , wherein the inner tube is an aspiration cannula that includes a side opening to align with the side aperture of the outer cannula. 
     
     
         52 . The method of  claim 48 , wherein the inner tube is an elongated cap-shaped plug and further comprising pushing the cap-shaped plug through the outer cannula and distal to the side aperture to seal the distal opening of the outer cannula. 
     
     
         53 . The method of  claim 52 , wherein pushing the cap-shaped plug includes pushing the plug with a push rod receivable in the outer cannula. 
     
     
         54 . The method of  claim 48 , wherein inserting the outer cannula into the bone comprises advancing the outer cannula into the bone with an adjustable depth guide. 
     
     
         55 . The method of  claim 54 , further comprising withdrawing the outer cannula from the bone with the adjustable depth guide.