Vascular access device
An access device for placing a medical article within a body space includes a syringe, a needle, and a sheath which are employed together with a guide wire. The sheath can be coaxially and slideably disposed about the needle. During insertion of the sheath over the needle, guide wire and into the body space, the syringe provides a negative pressure to ensure that any air located between the inside diameter of the sheath and the outside diameter of the needle is drawn into the needle rather than into the body space. In certain embodiments, a dilator is coaxially and slideably disposed about the needle and within the sheath.
1. An access device for placing a medical article within a body space, the access device comprising:
a barrel and a plunger slidingly disposed in the barrel, the plunger having a channel sized and shaped to receive a guide wire therethrough, the barrel defining a fluid chamber;
a plunger valve disposed in operative relationship relative to the channel to prevent passage of fluid through the channel during at least one operation performed from a group comprising flushing the access device and aspirating the access device;
an interior needle portion at least partially disposed in the channel and comprising an aperture through a side wall of the interior needle portion and into the fluid chamber;
a needle hub disposed on an exterior needle portion extending from the barrel and being in flow communication with the interior needle portion and the fluid chamber, the needle hub comprising a first locking structure and a second locking structure; and
a sheath coaxially disposed about the exterior needle portion and slideable along the exterior needle portion, a distal end of the sheath being positioned proximal to a distal end of the exterior needle portion; and
a dilator disposed about the exterior needle portion and within the sheath, the dilator comprising a dilator hub,
wherein the first locking structure is configured to releasably secure the needle hub to the barrel, and
wherein the second locking structure is configured to releasably secure the needle hub to the dilator hub.
2. The access device of claim 1 , wherein the plunger valve is configured to seal against the guide wire disposed in the channel.
3. The access device of claim 1 , wherein the plunger valve comprises one or more one-way valve elements.
4. The access device of claim 3 , wherein the one or more one-way valve elements comprises a flexible resilient hollow hemisphere member.
5. The access device of claim 1 , wherein the plunger valve is configured to prevent air from entering the channel during aspiration.
6. The access device of claim 1 , wherein the sheath comprises a sheath body, a sheath hub, and a sheath valve, the sheath hub defining an inner cavity, wherein the sheath valve is disposed in the inner cavity to inhibit flow through the inner cavity in a proximal direction.
7. The access device of claim 6 , wherein the sheath valve is configured to seal against the exterior needle portion.
8. The access device of claim 6 , wherein the sheath valve is biased to prevent gas from being drawn distally through the inner cavity.
9. An access device for placing a medical article within a body space, the access device comprising:
a syringe and a needle extending from the syringe, the syringe having a channel configured to receive a guide wire extending through the needle, the needle comprising a first locking structure and a second locking structure, wherein the syringe comprises a barrel and a plunger slidingly disposed in the barrel, wherein the plunger comprises a plunger channel configured to receive the guide wire;
a plunger valve disposed in operative relationship relative to the plunger channel to prevent passage of fluid through the plunger channel during at least one operation performed from a group comprising flushing the access device and aspirating the access device;
a sheath coaxially disposed about the needle and slideable along the needle; and
a dilator disposed about the needle and within the sheath,
wherein the first locking structure is configured to releasably secure the needle to the syringe, and
wherein the second locking structure is configured to releasably secure the needle to the dilator.
10. The access device of claim 9 , wherein the plunger valve is configured to seal against the guide wire disposed in the plunger channel.
11. The access device of claim 9 , wherein the plunger valve comprises one or more one-way valve elements.
12. The access device of claim 11 , wherein the one or more one-way valve elements comprises a flexible resilient hollow hemisphere member.
13. The access device of claim 9 , wherein the plunger valve is configured to prevent air from entering the plunger channel during aspiration.
14. The access device of claim 9 , wherein the sheath comprises a sheath body, a sheath hub, and a sheath valve, the sheath hub defining an inner cavity, wherein the sheath valve is disposed in the inner cavity to inhibit flow through the inner cavity in a proximal direction.
15. The access device of claim 14 , wherein the sheath valve is configured to seal against the needle.
16. The access device of claim 14 , wherein the sheath valve is biased to prevent gas from being drawn distally through the inner cavity.
17. A method for placing a medical article within a body space, the method comprising:
penetrating a blood vessel with an access device, the access device comprising:
a syringe and a needle extending from the syringe, the syringe having a channel configured to receive a guide wire extending through the needle, the needle comprising a first locking structure and a second locking structure, wherein the syringe comprises a barrel and a plunger slidingly disposed in the barrel, wherein the plunger comprises a plunger channel configured to receive the guide wire,
a plunger valve disposed in operative relationship relative to the plunger channel to prevent passage of fluid through the plunger channel during at least one operation performed from a group comprising flushing the access device and aspirating the access device, and
a sheath coaxially disposed about the needle and slideable along the needle,
a dilator disposed about the needle and within the sheath,
wherein the first locking structure is configured to releasably secure the needle to the syringe, and
wherein the second locking structure is configured to releasably secure the needle to the dilator;
feeding the guide wire through the channel, the needle, and into the blood vessel;
sliding the sheath along the needle in a distal direction until at least a portion of the sheath is disposed in the blood vessel; and
removing the syringe, the needle, and the guide wire from the blood vessel, leaving the sheath.
18. The method of claim 17 , wherein the plunger valve is configured to seal against the guide wire disposed in the plunger channel.
19. The method of claim 17 , wherein the plunger valve is configured to prevent air from entering the plunger channel during aspiration.
20. The method of claim 17 , wherein the sheath comprises a sheath body, a sheath hub, and a sheath valve, the sheath hub defining an inner cavity, wherein the sheath valve is disposed in the inner cavity to inhibit flow through the inner cavity in a proximal direction.
21. The method of claim 20 , wherein the sheath valve is configured to seal against the needle.
22. The method of claim 20 , wherein the sheath valve is biased to prevent gas from being drawn distally through the inner cavity.