Systems and methods for needle access to an intervertebral disc
A catheter with a balloon anchor may be sized to fit through an inner needle and introduced into the patient through the needle. The inner needle may comprise an atraumatic needle with a side port and/or a blunt tip. The catheter may include a radiopaque coil disposed over the distal portion of the catheter body to assist with catheter placement when viewed with fluoroscopy and/or x-ray. The distal portion of the catheter can be very flexible. A balloon inflation tube may terminate proximal to a proximal end of the expandable balloon anchor such that the distal portion of catheter can be flexible. This termination of the inflation tube may also position the inflation tube away from the annulus and nerve roots, so as to avoid irritation of the annulus and rubbing of the nerve roots that may potentially obscure FAD test results.
1. A catheter for accessing an intervertebral disc, said catheter comprising:
an elongate flexible catheter body having a proximal portion, a distal portion, and at least one lumen for housing an injection tube and an inflation tube;
the injection tube extending from the proximal portion to a distal tip of the catheter body, the injection tube being arranged to deliver an injection medium distally beyond an anchoring balloon into an intervertebral disc space;
an inflatable anchoring balloon on the distal portion of the catheter body;
an inflation tube extending from the proximal portion to the distal portion of the catheter body;
an attachment member removably coupled to a proximal portion of the inflation tube, the attachment member having a channel extending from a proximal end to a distal end of the attachment member, the attachment member having a slot opening extending from the proximal end to the distal end in communication with the channel;
a first Tuohy Borst connector removably coupled to the attachment member and the inflation tube;
a stopcock removably coupled to the first Tuohy Borst connector, the stopcock comprising a first pressure relief structure that vents an inflation medium if the pressure exceeds a predetermined pressure;
a first check valve upstream from and removably coupled to the stopcock, the first check valve ensures that the inflation medium only flows downstream in the direction of the stopcock;
a second pressure relief structure removably coupled to the first check valve; and
a first syringe removably coupled to the first check valve,
wherein the first syringe injects the inflation medium into the first check valve to inflate the inflatable anchoring balloon such that when the inflatable anchoring balloon reaches the predetermined pressure the second pressure relief structure opens and the inflation medium passes through an exit port of the second pressure relief structure in a visible manner such that a user of the catheter knows the predetermined pressure has been reached;
wherein the slot opening permits removal of the attachment member over the inflation tube such that the attachment member can be removed from the inflation tube while the first Tuohy Borst connector remains removably coupled to the inflation tube.
2. A catheter as in claim 1 , wherein the second pressure relief structure further comprises
a tubular body having an interior surface defining a channel in communication with the first check valve and the stopcock such that the inflation medium injected into the first check valve passes through the channel into the stop cock;
a seal forming a portion of the interior surface of the channel, the seal formed by a spring exerting a second predetermined pressure against a ball causing the ball to sealing interface with a seat; wherein the predetermined pressure is greater than the second predetermined pressure such that the seal is broken and the inflation medium passes through the exit port.
3. A catheter as in claim 1 , wherein the attachment member is a first wing nut.
4. A catheter as in claim 1 , further comprising:
a second wing nut removably coupled to a proximal portion of the injection tube;
a second Tuohy Borst connector removably coupled to the second wing nut and the injection tube;
a third check valve upstream from and removably coupled to the second Tuohy Borst, the second check valve ensures that the injection medium only flows downstream in the direction of the second Tuohy Borst; and
a connector operable to connect to a second syringe that injects the injection medium into the connector.