Systems and methods for treating a hollow anatomical structure
A working end of a catheter includes at least one therapeutic element, such as a resistive heating element, usable to deliver energy for ligating, or reducing the diameter of, a hollow anatomical structure. In certain examples, the catheter includes a lumen to accommodate a guide wire or to allow fluid delivery. In certain embodiments, a balloon is inflated to place resistive element(s) into apposition with a hollow anatomical structure and to occlude the structure. Indexing devices and methods are also disclosed for successively treating portions of the hollow anatomical structure. In certain examples, marks along the catheter shaft provide visual verification to the physician of the relative position of the therapeutic element of the catheter. Embodiments of indexing devices may include pairs of rings and/or hinged arms that move a catheter a desired indexed position between successive treatments.
1 . A catheter for use in treating a hollow anatomical structure, the catheter comprising:
an elongated shaft having a distal end and a proximal end;
an energy application device located proximate the distal end of the shaft, the energy application device having a first length; and
a plurality of index markers located along the shaft and proximal of the energy application device such that consecutive index markers are spaced apart by a second length, the second length comprising an indexing distance of the energy application device.
2 . The catheter of claim 1 , wherein the second length is approximately equal to or slightly shorter than the first length.
3 . The catheter of claim 2 , wherein the first length is between approximately 2 centimeters and approximately 10 centimeters and the second length is between approximately 0.1 centimeter and approximately 1.5 centimeters less than the first length.
4 . The catheter of claim 3 , wherein the first length is approximately 7 centimeters and the second length is approximately 6.5 centimeters.
5 . The catheter of claim 1 , wherein the shaft further comprises a stop-treatment marker located proximal of the energy application device and distal of the plurality of index markers.
6 . The catheter of claim 1 , wherein the shaft further comprises a last-treatment marker located proximal of the energy application device and distal of the plurality of index markers.
7 . The catheter of claim 5 , wherein the stop-treatment marker includes a plurality of warning markers corresponding to a plurality of introducer lengths.
8 . The catheter of claim 1 , wherein the plurality of index markers comprises alphanumeric markers.
9 . The catheter of claim 1 , wherein the plurality of index markers comprises color-coded markers.
10 . The catheter of claim 1 , wherein the plurality of index markers comprises geometrically coded markers.
11 . The catheter of claim 1 , wherein the plurality of index markers comprises at least one magnetic ink marker readable by an external sensor.
12 . The catheter of claim 1 , wherein the plurality of index markers comprises at least one detent in the shaft.
13 . The catheter of claim 1 , wherein at least a portion of the catheter is sterile.
14 . A method comprising sterilizing the catheter of claim 1 .
15 . The catheter of claim 1 , wherein said energy application device has an adjustable active length.
16 . The catheter of claim 1 , wherein said energy application device has an active region which is adjustable in size.
17 . The catheter of claim 16 , wherein said energy application device comprises a heater element with a plurality of separately operable heater sections which are arranged longitudinally along said first length.
18 . A method for treating a hollow anatomical structure, the method comprising:
inserting a catheter having an energy application device having a first length and indexing marks on the catheter shaft proximal to the energy application device through an introducer sheath in a hollow anatomical structure of a patient;
positioning the energy application device at a first treatment location in the hollow anatomical structure;
while the energy application device is at the first treatment location of the hollow anatomical structure, withdrawing the sheath or adjusting a reference point of the sheath until the reference point of the sheath is aligned with one of the indexing marks on the catheter shaft;
applying energy with the energy application device to the first treatment location in the hollow anatomical structure;
positioning the catheter at one or more subsequent treatment locations in the hollow anatomical structure by moving the catheter shaft through the sheath until another one or more of the indexing marks is aligned with the reference point of the sheath; and
applying energy with the energy application device to each subsequent treatment location.
19 . The method of claim 18 , wherein the reference point of the sheath comprises the proximal end of the sheath.
20 . The method of claim 18 , wherein the reference point of the sheath comprises an adjustable reference marker.
21 . The method of claim 18 , further comprising securing the sheath with respect to the hollow anatomical structure before moving the catheter to one or more subsequent treatment locations.
22 . The method of claim 21 , wherein securing the sheath comprises securing the sheath to the patient.
23 . A method for treating a hollow anatomical structure, the method comprising:
inserting a catheter into a hollow anatomical structure of a patient, the catheter having an energy application device with a first length;
applying energy, with the energy application device, to a first treatment location of the hollow anatomical structure;
moving the catheter proximally to one or more additional treatment locations of the hollow anatomical structure, wherein each additional treatment location is offset by an indexing length from the preceding treatment location; and
applying energy, with the energy application device, to the one or more additional treatment locations of the hollow anatomical structure.
24 . The method of claim 23 , wherein the indexing length is approximately equal to or slightly shorter than the first length.
25 . The method of claim 23 , wherein said moving comprises aligning an index marking on the catheter with a reference point.
26 . The method of claim 25 , wherein the reference point is on an introducer through which the catheter is inserted.
27 . The method of claim 23 , additionally comprising monitoring a temperature within the hollow anatomical structure.
28 . The method of claim 23 , wherein applying energy to said first location comprises applying energy to said first location at two distinct times.
29 . The method of claim 23 , wherein applying energy to said first location comprises applying energy to said first location for a longer duration than to any one of said additional locations.
30 . The method of claim 29 , wherein said hollow anatomical structure has a larger cross-sectional profile, as viewed along a longitudinal axis of said hollow anatomical structure, in said first location than in any of said additional locations.
31 . The method of claim 29 , wherein said hollow anatomical structure comprises the great saphenous vein, and said first location is closer to the sapheno-femoral junction than is any of said additional locations.
32 . An apparatus comprising:
a catheter shaft extending from a proximal end to a distal end;
an energy application device proximate the distal end of the catheter shaft; and
markers along the length of the catheter shaft, the markers being spaced apart at a multiple of the length of the energy application device.
33 . The apparatus of claim 32 , wherein the length of the energy application device is between approximately 2 centimeters and approximately 10 centimeters.
34 . The apparatus of claim 32 , wherein the energy application device is a resistive heating device.
35 . The apparatus of claim 34 , wherein the energy application device is a wound nichrome wire.
36 . The apparatus of claim 32 , wherein said energy application device comprises a Resistance Temperature Detector (RTD) configured to sense the temperature of said energy application device by a measurement of the impedance of said energy application device.
37 . The apparatus of claim 32 , wherein the energy application device comprises one or more radio frequency (RF) electrodes.
38 . The apparatus of claim 32 , wherein the markers are spaced apart at a fraction of the length of the energy application device.
39 . The apparatus of claim 32 , further comprising at least one temperature sensor.
40 . The apparatus of claim 32 , wherein at least a portion of the apparatus is sterile.
41 . A method comprising sterilizing the apparatus of claim 32 .
42 . The apparatus of claim 32 , wherein said energy application device has an adjustable active length.
43 . The apparatus of claim 32 , wherein said energy application device has an active region which is adjustable in size.
44 . The apparatus of claim 43 , wherein said energy application device comprises a heater element with a plurality of separately operable heater sections which are arranged longitudinally.
45 . A method for treating a hollow anatomical structure, the method comprising:
inserting a catheter having a heating element coupled thereto, into a hollow anatomical structure;
energizing the heating element at a first treatment position within the hollow anatomical structure;
moving the catheter an indexed distance in a proximal direction to an additional treatment position within the hollow anatomical structure; and
energizing the heating element at the additional treatment position.
46 . The method of claim 45 , further comprising repeating:
(a) moving the catheter an indexed distance to an additional treatment position; and
(b) energizing the heating element at the additional treatment position;
until a desired length of the hollow anatomical structure is treated.
47 . The method of claim 45 , wherein the hollow anatomical structure comprises a human vein.
48 . The method of claim 45 , further comprising determining the indexed distance with a plurality of markings along a shaft of the catheter.
49 . The method of claim 45 , wherein said moving the catheter the indexed distance comprises:
securing a proximal end of an indexing device to a shaft of the catheter; and
extending the proximal end of the indexing device the indexed distance from a distal end of the indexing device, thereby moving the catheter shaft by the indexed distance from the distal end of the indexing device.
50 . The method of claim 45 , wherein at least one of the additional treatment locations slightly overlaps the preceding treatment location.
51 . The method of claim 45 , wherein energizing the heating element at the first treatment position comprises energizing the heating element at two distinct times.
52 . The method of claim 45 , wherein energizing the heating element at the first treatment position comprises energizing the heating element for a longer duration than at any one of the additional treatment positions.
53 . The method of claim 52 , wherein said hollow anatomical structure has a larger cross-sectional profile, as viewed along a longitudinal axis of said hollow anatomical structure, in said first treatment position than in any of said additional treatment positions.
54 . The method of claim 52 , wherein said hollow anatomical structure comprises the great saphenous vein, and said first treatment position is closer to the sapheno-femoral junction than is any of said additional treatment positions.
55 . A catheter for treating a hollow anatomical structure, the catheter comprising:
an elongate shaft;
means for applying energy to a hollow anatomical structure, said means for applying energy secured to said shaft, said means for applying energy having a first length; and
a plurality of means for indexing located along said shaft and proximal of said means for applying energy, each of the plurality of means for indexing being spaced apart by a second length.
56 . The catheter of claim 55 , wherein the second length is approximately equal to or slightly less than the first length.
57 . The catheter of claim 55 , wherein the means for applying energy comprises a resistive heating device.
58 . A catheter for use in treating a hollow anatomical structure, the catheter comprising:
an elongated shaft having a distal end and a proximal end;
an energy application device coupled to the shaft, the energy application device having a first length; and
a plurality of index markers located along the shaft and proximal of the energy application device such that consecutive index markers are spaced apart by a second length, the second length being equal to the first length less a decrement, the decrement being between 1% and 15% of the first length.
59 . The catheter of claim 58 , wherein the first length is between 2 and 10 centimeters, and the decrement is between 0.1 and 1.5 centimeters.
60 . The catheter of claim 58 , wherein the first length is approximately 7 centimeters and the second length is approximately 6.5 centimeters.
61 . The catheter of claim 58 , wherein the shaft further comprises a stop-treatment marker located distal of the plurality of index markers, the stop-treatment marker being distinct from the index markers.
62 . The catheter of claim 58 , wherein the energy application device comprises an electrically driven heater element.
63 . The catheter of claim 58 , wherein the energy application device has an energy coupling surface which extends along the first length.
64 . The catheter of claim 63 , wherein the first length is at least ten times a width of the energy application device.
65 . The catheter of claim 58 , wherein the energy application device is configured to generate heat internally and transfer heat radially outwardly away from a central longitudinal axis of the energy application device.
66 . An introducer sheath, comprising:
a sheath lumen having a distal end which is insertable into a hollow anatomical structure, said sheath lumen extending generally along a luminal axis in a distal-to-proximal direction;
an adjustable reference marker connected to said sheath, the longitudinal position, as measured along said luminal axis, of said reference marker being adjustable.
67 . A hollow anatomical structure treatment system comprising the sheath of claim 66 , and
a catheter shaft disposed in said sheath lumen, said catheter shaft extending proximally past said reference marker, said catheter shaft having a plurality of indexing marks;
wherein said reference marker is longitudinally adjustable relative to said catheter shaft to permit alignment of said reference marker with one of said indexing marks without need for movement of said shaft relative to said sheath.
68 . The sheath of claim 66 , wherein the adjustable reference marker includes a flexible elongate member of variable length that is attached to the proximal end of said sheath.
69 . The sheath of claim 66 , wherein said adjustable reference marker is removably connected to said sheath.