Aspiration catheter systems and methods of use
Methods, systems, and devices for facilitation of intraluminal medical procedures within the neurovasculature including catheters and catheter advancement elements.
1 . A catheter system, the system comprising:
a catheter comprising a lumen and a distal end having an opening from the lumen; and
a catheter advancement element comprising:
a tubular portion having an inner diameter and an outer diameter;
a tapered tip portion located distal to the tubular portion, wherein a length of the tapered tip portion is at least 1 cm up to 4 cm; and
a radiopaque marker band identifying a proximal end of the tapered tip portion,
wherein the catheter system has an assembled configuration characterized by the catheter advancement element positioned within the lumen of the catheter and the radiopaque marker band substantially aligned with the distal end of the catheter, and
wherein the radiopaque marker band locally increases stiffness of the catheter advancement element, wherein when the catheter and the catheter advancement element are in the assembled configuration, the radiopaque marker band minimizes a step-up from a bending force of the tapered tip portion to a bending force of the distal end of the catheter.
2 . The catheter system of claim 1 , wherein a ratio of a bending force of a proximal point of the tapered tip portion to a bending force of a distal point of the tapered tip portion is at least 2.
3 . The catheter system of claim 1 , wherein the bending force of the catheter advancement element increases along a length of the tapered tip portion to the radiopaque marker band, and wherein the bending force of the catheter advancement element decreases proximal to the radiopaque marker band.
4 . The catheter system of claim 1 , wherein an additive bending force of the catheter system between the catheter and the catheter advancement element gradually increases from a distal end of the catheter system towards a proximal end of the catheter system.
5 . The catheter system of claim 4 , wherein the additive bending force gradually increases without a step-increase in slope.
6 . The catheter system of claim 1 , wherein the radiopaque marker band is embedded within or positioned over a wall of the tubular portion.
7 . The catheter system of claim 1 , wherein a first radiopaque marker band is positioned at a distal end of the tapered tip portion and a second radiopaque marker band is positioned at the proximal end of the tapered tip portion.
8 . The catheter system of claim 7 , wherein the second radiopaque marker band has a proximal edge, a distal edge, and a width between the proximal edge and the distal edge, and the proximal edge of the second radiopaque marker band can align substantially with the distal end of the catheter such that the second radiopaque marker band remains external to the lumen of the catheter.
9 . The catheter system of claim 1 , wherein the tubular portion has a region of relatively uniform outer diameter extending along at least a portion of a length of the tubular portion.
10 . The catheter system of claim 1 , wherein the tapered tip portion has a transition in flexibility along a length of the tapered tip portion.
11 . The catheter system of claim 10 , wherein the tapered tip portion has an overall maximum flexibility at a distal-most end of the tapered tip portion.
12 . The catheter system of claim 10 , wherein the transition in flexibility from the tapered tip portion to the flexibility of the catheter system as a whole is defined by a slope that includes no step increase and is substantially constant.
13 . The catheter system of claim 1 , wherein the tapered tip portion in the assembled configuration has at least three points spaced along the length of the tapered tip portion, the at least three points comprising:
a distal point of the at least three points located a distance proximal from a distal-most end of the catheter advancement element;
an intermediate point of the at least three points located a distance proximal from the distal point, the intermediate point having a second bending force; and
a proximal point of the at least three points located a distance proximal from the intermediate point, the proximal point having a third bending force; and
wherein the catheter system in the assembled configuration has at least two system points along a length of the catheter system, the at least two system points comprising:
a first system point of the at least two system points located proximal to the distal-most end of the catheter, the first system point having a first system bending force; and
a second system point of the at least two system points located distal to the first system point by a distance that is at least about 1 mm distal to the distal-most end of the catheter, wherein the second system point can be the same or different from the proximal point, the second system point having a second system bending force,
wherein a difference between the second bending force and the first bending force divided by a distance between the distal point and the intermediate point equals a first flexibility slope;
wherein a difference between the third bending force and the second bending force divided by a distance between the intermediate point and the proximal point equals a second flexibility slope;
wherein an average of the first flexibility slope and the second flexibility slope defines an average tip portion flexibility slope;
wherein a difference between the first system bending force and the second system bending force divided by a distance between the first system point and the second system point equals a third flexibility slope; and
wherein a ratio of the third flexibility slope to the average tip portion flexibility slope is less than about 25.
14 . A catheter system, the system comprising:
a catheter comprising a lumen and a distal end having an opening from the lumen, the lumen having an inner diameter at the distal end of at least 0.052″; and
a catheter advancement element comprising:
a tubular portion having a single lumen with an inner diameter that is at least 0.014″ up to 0.024″ and an outer diameter that is between 0.048″ and 0.080″ and sized to substantially fill the lumen of the catheter;
at least one radiopaque marker located near a snug point;
a tubular, polymer tip portion located distal to the snug point, wherein the tip portion tapers along a length that is at least 1 cm up to 4 cm of the tip portion; and
a proximal hub coupled to a proximal end of the catheter advancement element a distance away from the distal end of the catheter advancement element, the proximal hub sized to remain outside the catheter lumen,
wherein a bending force of the catheter advancement element increases along a length of the tip portion to the at least one radiopaque marker located near the snug point and then decreases proximal to the snug point,
wherein the catheter system has an assembled configuration characterized by the catheter advancement element positioned within the lumen of the catheter, wherein the snug point of the tubular portion is substantially aligned with the distal end of the catheter, and
wherein, when in the assembled configuration, the catheter system transitions in flexibility from a distal end of the tip portion to a point located proximal to the distal end of the catheter that is defined by a slope that is substantially constant and includes no step-increase.
15 . The catheter system according to claim 14 , wherein the tip portion increases in stiffness over the length of the tip portion such that a proximal end of the tip portion has a stiffness that is at least twice as stiff as a stiffness of the distal end of the tip to approach a bending force of the distal end of the catheter.
16 . The catheter system according to claim 14 , wherein the bending force of the catheter advancement element that increases along the length of the tip portion increases at a generally constant slope.
17 . The catheter system according to claim 14 , wherein a second radiopaque marker band is positioned at a distal end of the length of the tip portion and the at least one radiopaque marker band is positioned at a proximal end of the length of the tip portion.
18 . The catheter system according to claim 14 , wherein the bending force of the catheter advancement element decreases proximal to the snug point and remains lower than a bending force of the catheter over a length.
19 . The catheter system according to claim 14 , wherein the catheter advancement element undergoes a transition in flexibility from a distal-most end towards the snug point.
20 . The catheter system according to claim 14 , wherein an additive bending force of the catheter system between the catheter and the catheter advancement element gradually increases from a distal end of the catheter system towards a proximal end of the catheter system.
21 . The catheter system according to claim 20 , wherein the additive bending force gradually increases without a step-increase in slope.
22 . The catheter system of claim 14 , wherein the tip portion in the assembled configuration has at least three points spaced along the length of the tip portion, the at least three points comprising:
a distal point of the at least three points located a distance proximal from a distal-most end of the catheter advancement element;
an intermediate point of the at least three points located a distance proximal from the distal point, the intermediate point having a second bending force; and
a proximal point located a distance proximal from the intermediate point, the proximal point having a third bending force; and
wherein the catheter system in the assembled configuration has at least two system points along a length of the catheter system, the at least two system points comprising:
a first system point of the at least two system points located proximal to the distal-most end of the catheter, the first system point having a first system bending force; and
a second system point of the at least two system points located distal to the first system point by a distance that is at least about 1 mm distal to the distal-most end of the catheter, wherein the second system point can be the same or different from the proximal point, the second system point having a second system bending force,
wherein a difference between the second bending force and the first bending force divided by a distance between the distal point and the intermediate point equals a first flexibility slope;
wherein a difference between the third bending force and the second bending force divided by a distance between the intermediate point and the proximal point equals a second flexibility slope;
wherein an average of the first flexibility slope and the second flexibility slope defines an average tip portion flexibility slope;
wherein a difference between the first system bending force and the second system bending force divided by a distance between the first system point and the second system point equals a third flexibility slope; and
wherein a ratio of the third flexibility slope to the average tip portion flexibility slope is less than about 25.