Source: https://patents.google.com/patent/US9750564B2/en
Timestamp: 2018-08-17 19:19:47
Document Index: 120261471

Matched Legal Cases: ['art 14', 'art 14', 'art 14', 'art 14', 'art 14', 'art 14', 'art 14', 'art 14', 'art 14', 'art 14', 'art 14', 'art 14', 'art 14', 'art 14', 'art 14', 'art 14', 'art 14', 'art 14', 'art 14', 'art 14', 'arts 14']

US9750564B2 - Flexible catheter for high-frequency therapy of biological tissue and method of using same - Google Patents
US9750564B2
US9750564B2 US12085720 US8572007A US9750564B2 US 9750564 B2 US9750564 B2 US 9750564B2 US 12085720 US12085720 US 12085720 US 8572007 A US8572007 A US 8572007A US 9750564 B2 US9750564 B2 US 9750564B2
US20090156981A1 (en )
A catheter for the high-frequency therapy of body lumens has a flexible shaft tube of preferably biocompatible plastic material, which is connected to a distal end piece in the region of the distal end of the catheter. A proximal part of the distal end piece, that projects into the distal part of the shaft tube, forms a damping connection to the distal end of the shaft tube, which is secured by a distal electrode which is drawn on to the external peripheral surface of the shaft tube, by the distal electrode exerting a radially inwardly acting clamping force on the damping connection.
a distal end piece fixed to the distal end of the flexible shaft tube.
In accordance with the invention that object is attained by a catheter of the kind set forth in the opening part of this specification, having a distal end piece which projects with a proximal end portion into the lumen of the flexible shaft tube and there forms a clamping connection to the distal end of the shaft tube. The clamping connection is secured in that case by a sleeve in the form of a hollow cylinder which exerts a radially acting damping force on the clamping connection. Preferably for that purpose the sleeve is pulled on to the external peripheral surface of the flexible shaft tube in order to secure the clamping connection from the outside, by a radially inwardly acting force. In the event that the end piece has a central through bore, the sleeve in a further embodiment can also be pushed into the end piece and can thus secure the clamping connection from the inside by a radially outwardly acting force.
Preferably the distal end piece has a proximal part with at least one change in cross-section on the external peripheral surface, which makes it more difficult to displace the end piece in the axial direction. The change in cross-section is preferably in the form of a radially outwardly protruding projection.
In accordance with its two main configurations, the catheter shaft is either closed at the distal end or it has an opening at the distal end of the shaft. In this main configuration which is referred to as the second one, the catheter shaft has an internal lumen—which is continuous from the distal end to the proximal end of the catheter—and which is preferably of such a configuration that a guide wire can pass into the lumen through the proximal opening and can issue again through the distal opening. If in accordance with the main configuration referred to as the first configuration, the catheter is closed at the distal end, then in accordance with a further design configuration it can have a cooling system which is connected to a proximal feed and discharge flow of a coolant and which circulates within the lumen of the catheter, that is dosed to the distal end.
At the distal end of the shaft tube the lines are preferably connected to the electrodes by a clamping contacting arrangement. In that case the lines are clamped between the electrode and the shaft tube by the radially inwardly acting clamping force of the electrodes so that an electrical contact is afforded. In order to guide the electric lines from the intermediate space between the internal peripheral surface of the shaft tube and the external peripheral surface of the plastic hose through the periphery of the shaft tube on to the external peripheral surface of the shaft tube, radially oriented passage means are provided in the peripheral surface of the shaft tube. The distal end portions of the lines are passed 15 through those passage means and bent in such a way that they extend in the longitudinal direction of the shaft tube between the outer peripheral surface of the shaft tube and the respective electrode, and are clamped there.
In accordance with a further embodiment, the distal end piece which is normally made in one piece can be divided into two and can comprise a proximal and a distal sub-piece, wherein the proximal and the distal sub-pieces of the end piece are connected together by way of a force-locking connection, a positively locking connection or a connection involving intimate joining of the materials concerned. Preferably a distal portion of the proximal sub-piece of the end piece surrounds the proximal portion of the distal sub-piece, but a reversed arrangement of the two sub-pieces is also provided in accordance with a further embodiment.
If the end piece is divided into two the sleeve preferably encloses both sub-pieces of the distal end piece at least over a partial length where a distal portion of the proximal sub-piece of the end piece surrounds a proximal portion of the distal sub-piece.
Suitable recesses on the external peripheral surface of the proximal portion of the distal sub-piece of the end piece can serve as an adhesive reservoir, by means of which a secure adhesive join is afforded between the distal and the proximal sub-pieces.
In a further variant a distal part of the end piece is in the form of a pointed tip. In accordance with the main variant of the catheter with a distal opening, the pointed tip is correspondingly provided with an axial through bore forming a distal mouth opening of the lumen. The pointed tip preferably comprises polyphenylsulfone (PPSU) or polyetheretherketone (PEEK) and can optionally also be provided with an anti-adhesion coating.
Depending on the respective embodiment involved, the distal end piece at its distal end has a mouth diameter of 0.65 to 2 mm. The distal part, of a frustoconical configuration, of the distal end piece serves in particular to simplify the intraluminal advance of the catheter.
In a further embodiment the electrode can also be designed with a head-shaped, conical, trocar-shaped or spherical end face and thus at the same time can form the distal end piece.
In endoluminal use the hollow organ to be treated and possibly tumor tissue thereagainst have current flowing therethrough, they experience a rise in temperature and coagulate.
Treatment procedure on the example of varicose veins: A blood vessel to be treated is firstly preferably opened for example in the proximity of the ankle. A guide wire is then introduced under some circumstances by means of an endoscope into the opened vein. As the second step in the procedure the high-frequency catheter is introduced with its distal end leading into the opened vein over the guide wire and advanced as far as the end of the vein. In that case a high-frequency ac voltage which results in coagulation is not yet applied to the electrode or electrodes of the high-frequency catheter.
FIG. 1 is a perspective cross-sectional view showing a distal end piece of a catheter for the high-frequency therapy of biological tissue with a flexible shaft tube, an internal lumen extending therethrough, a plastic material hose which is drawn into the lumen of the shaft tube, a plastic tip, two ring electrodes, two electric lines and an insulator,
FIG. 1a is a perspective view in partial cross-section showing a plastic material tube and a conical plastic material tip as constituent parts of the catheter of FIG. 1, shown separately,
FIG. 1b is a perspective cross-sectional view showing a flexible shaft tube as a constituent part of the catheter of FIG. 1, shown separately,
FIG. 1c is a perspective cross-sectional view showing electrodes and electric lines of the catheter of FIG. 1, shown separately,
FIG. 1d is a perspective cross-sectional view showing an insulator arranged between the electrodes as a constituent part of the catheter of FIG. 1, shown separately,
FIG. 2 is a side elevational view of the distal end piece of a catheter in accordance with a second embodiment of the invention,
FIG. 2A is a cross-sectional view taken along the A-A line of FIG. 2 of the distal end piece of a catheter in accordance with a second embodiment with the flexible shaft tube, an internal lumen extending therethrough, a distal end piece which is divided into two, two ring electrodes and an insulator,
FIG. 3 is a cross-sectional view of the distal end piece of a catheter in accordance with a third embodiment with a flexible shaft tube, an internal lumen which is closed at its distal end, a distal end piece which is divided into two and a cooling system, and
Referring to FIGS. 1 through 1 d, a distal end piece of the high-frequency catheter according to the invention is shown in a particularly preferred embodiment; comprising a lumen 1 extending therethrough for passing a guide wire therethrough; in a bipolar variant.
The distal end of the catheter has a distal end piece 14. A distal part 14.d of the end piece 14 is in the form of a plastic material tip, while a cylindrical proximal part 14.p of the end piece 14, which projects into the distal end of a flexible shaft tube 16, forms a clamping connection to the distal end of the flexible shaft tube 16.
The end piece 14 has a central bore which opens into the lumen 1 which extends as far as the proximal end of the catheter. The external peripheral surface of the distal part 14.d, which is in the form of a frustoconical plastic tip, of the distal end piece 14 extends at an angle of 15 degrees as measured between the conical peripheral surface and a line parallel to the axis of the catheter, wherein the outside diameter of the plastic material tip goes steplessly into the outside diameter of a distal ring electrode 18. At the transition between the distal part 14.d and the proximal part 14.p of the distal end piecedistal end piece 14 therefore the outside diameter of the distal part 14.d which is in the form of the plastic tip corresponds to the outside diameter of the distal ring electrode 18.
In the variant illustrated here, besides the distal ring electrode 18, a proximal ring electrode 20 is drawn on to the shaft tube 16 of the catheter. The two ring electrodes 18, 20 are preferably formed from a biocompatible high-quality steel. In this embodiment, the distal ring electrode 18 has the function of a sleeve which secures the clamping connection between the shaft tube 16 and the proximal part 14.p of the end piece 14 insofar as it exerts a radially inwardly directed damping force on the part of the shaft tube 16 enclosed thereby, and thereby increases the clamping force between the shaft tube 16 and the distal end piece 14.
It is not possible to see from FIG. 1 that the proximal part 14.p of the end piece 14 can have a variation in cross-section of the outer diameter, for example in the form of a projection which circumferentially extends in a ring shape and which hinders an axial displacement of the end piece 14 within the shaft tube 16 and thus guarantees an even stronger hold for the distal electrode 18 on the shaft tube 16.
The distal electrode 18 is preferably at a spacing of 1.8 mm relative to the distal end of the catheter and a length measured in the longitudinal direction of the catheter of about 5.4 mm. The insulator 26 is of a length which constitutes approximately 10% of the active part, which is preferably 12 mm long, consisting of the distal electrode 18+insulator 26+proximal electrode 20, and which is thus 1.2 mm. The proximal electrode is preferably of the same length as the distal electrode 18.
For insulating the lines 22 and 24 and for fixing them to the internal peripheral surface of the shaft tube 16, a plastic material hose 12 is drawn into the lumen 1 of the shaft tube 16. The hose 12 extends from the proximal end (not visible) of the catheter to the junction between the proximal part 14.p and the distal part 14.d of the end piece 14.
Consequently, the lines 22 and 24 extend between the passages 28 and 30 and the proximal end of the catheter in an intermediate space between the shaft tube 16 and an internal plastic tube 12.
FIGS. 1a through 1d show the catheter of FIG. 1, illustrated separately. FIG. 1a shows the plastic hose 12 with the distal part 14.d of the end piece 14, the part 14.d being in the form of a plastic material tip. It can be seen at the distal end of the plastic tip that the entry to the central bore is of a funnel-shaped configuration, wherein the internal peripheral surface at that location extends at an angle of about 45 degrees as measured between the conical internal peripheral surface and a line parallel to the axis of the catheter. That funnel-shaped configuration makes it easier to receive a guide wire.
The plastic hose 12 is advanced as far as the junction between the proximal part 14.p and the distal part 14.d of the end piece 14 in the central bore of the end piece 14. In this variant the plastic hose 12 and the end piece 14 can be joined together by way of a press fit or also by a welded connection or an adhesive connection.
FIG. 1b shows a view in section of the flexible shaft tube 16. It is possible to clearly see therein the two passages 28 and 30 for the lines 22 and 24.
FIG. 1c shows a sectional view of the distal electrode 18 and the proximal electrode 20 with the associated electric lines 22 and 24. The electric lines 22 and 24 extend from the proximal end of the catheter to the respective passages 28 and 30 provided for same, parallel to the longitudinal axis of the catheter. After having passed through the respective passage in the periphery of the shaft tube 16, for which purpose they have a first bend through 90 degrees corresponding to the radial orientation of the passages 28 and 30, they also extend after having passed through the peripheral surface of the shaft tube 16 preferably in the axial-distal or axial-proximal direction, and correspondingly have a second bend through 90 degrees. By virtue of the ring electrodes 18 and 20 being drawn on to the shaft tube 16 the lines 22 and 24 are clamped by the radially inwardly acting clamping force of the electrodes 18 and 20 between the respective electrode 18 or 20 and the shaft tube 16, thereby providing the clamping contacting action between the lines 22 and 24 and the electrodes 18 and 20. In alternative variants the connection between the lines and the respective electrode can be made additionally or exclusively by a join involving intimate bonding of the materials concerned, such as for example adhesive or soldering.
FIG. 1d shows a view in section of the insulator 26.
The difference in relation to the variant shown in FIG. 1 is in particular that the distal end piece 14 is divided into two and comprises a distal sub-piece 14.1 and a proximal sub-piece 14.2.
A proximal cylindrical part 14.p of the proximal sub-piece 14.2 projects in this case into the distal end of the shaft tube 16 and forms a clamping connection with the distal end of the flexible shaft tube 16. As was not shown in FIG. 1, this illustration shows a variation in cross-section on the external peripheral surface of the proximal part 14.p of the proximal sub-piece 14.2. As already described that variation in cross-section enhances the load-bearing capability of the clamping connection and hinders axial movement of the proximal sub-piece 14.2.
The proximal sub-piece 14.2 is preferably made from metal in order to be able to carry a greater radial force acting due to the sleeve or the distal ring electrode 18 and to increase the load-bearing capability of the clamping connection.
At the location at which the proximal sub-piece 14.2 projects out of the shaft tube 16, the outside diameter of the sub-piece 14.2 is enlarged to the outside diameter of the shaft portion 16 and fixes the sub-piece 14.2 in relation to a distally directed axial movement.
A further cross-sectional enlargement of the outside diameter of the proximal sub-piece 14.2 to the outside diameter of the distal ring electrode 18 forms a flange at the distal end of the proximal sub-piece 14.2 and prevents axial displacement of the distal ring electrode 18 in the distal direction.
In order to connect the distal sub-piece 14.1 to the proximal sub-piece 14.2 a distal part 14.z of the proximal sub-piece 14.2 encloses the proximal part 14.z of the distal sub-piece 14.1. Provided on the external peripheral surface of the distal sub-piece 14.1, in a proximal part 14.z, are cross-sectional changes which are compatible with the cross-sectional changes of the internal peripheral surface of the proximal sub-piece 14.2 in a distal part 14.z and thus permit a latching connection between the two sub-pieces 14.1 and 14.2. In this variant the clamping or latching connection is also secured by the distal ring electrode 18 which secures both connections by the radially acting force on the parts 14.z and 14.p.
In this variant also the distal sub-piece 14.1 has a distal part which is in the form of a tip and is preferably made from plastic material. The variant of the distal end piece 14 with two sub-pieces 14.1 and 14.2, described with reference to FIGS. 2 and 2A, has the advantage over the variant described with reference to FIG. 1 that the two sub-pieces 14.1 and 14.2 of the distal end piece 14 can be formed from different materials.
As also in the second embodiment, the diameter of the lumen 1 in the embodiment illustrated here goes from the inside diameter of the flexible shaft tube 16 into the inside diameter of a distal end piece which is divided into two distal sub-pieces 14.1, 14.2. The proximal part of the distal end piece 14.2 in this arrangement has a through bore. Unlike the embodiments shown hitherto, the distal sub-piece 14.1 of the two sub-piece end piece however has a blind bore. Accordingly, in contrast to the embodiments 1 and 2, the lumen of the catheter ends in the blind bore of the distal sub-piece 14.1 of the two sub-pieces of the end piece. The internal space in the catheter is therefore enclosed so that no fluid can pass from the interior of the catheter outwardly or vice-versa.
The catheter shown in FIG. 3 also has a cooling system with a proximal feed and discharge flow (not shown here) for a cooling medium. In this case the cooling system shown here is formed by a feed conduit 32 which is held only at the proximal end (not shown) of the catheter and the distal end of which can move relatively freely in the distal end of the catheter and, as shown here, in the bore in the distal end sub-pieces 14.1, 14.2. Like the shaft tube 16 the feed conduit 32 is made from a flexible plastic material, for example PEEK. In this case a catheter in this embodiment can be flushed with a cooling fluid. For that purpose a cooling medium is fed to the feed conduit 32 by way of a proximal feed flow means, the cooling medium issuing from a distal mouth opening 33 of the feed conduit 32 and in so doing cooling in particular the distal end of the catheter. By virtue of the closed distal shaft end the cooling medium thereupon flows back through an intermediate space 34 between the outside diameter of the feed conduit 32 and the inside diameter of the flexible shaft tube 16 to the proximal end of the shaft where it issues from the catheter at the proximal discharge flow means.
1. A catheter for the treatment of body tissue comprising:
a distal end piece fixed to a distal end of the flexible shaft tube, a proximal end of the distal end piece projects into the lumen of the flexible shaft tube and there forms a clamping connection to the distal end of the flexible shaft tube, wherein the distal end piece is divided into a proximal sub-piece having at least one change in outside diameter and a distal sub-piece, wherein the proximal end of the distal end piece is part of the proximal sub-piece, and the distal sub-piece is connected to the proximal sub-piece by a distal part of the proximal sub-piece enclosing a proximal part of the distal sub-piece,
at least one electrode on a distal portion of the flexible shaft tube adapted to deliver high-frequency alternating current to body tissue surrounding the catheter during treatment, wherein the distal portion of the flexible shaft tube comprises the distal end of the flexible shaft tube, wherein said at least one electrode includes a sleeve in the form of a hollow cylinder which exerts a radially acting clamping force on the clamping connection, and
at least one electric line which is electrically conductingly connected to the at least one electrode and which extends to a proximal end of the catheter.
2. A catheter as set forth in claim 1, wherein the sleeve is electrically conducting and forms the at least one electrode on the distal portion of the flexible shaft tube.
3. A catheter as set forth in claim 1, wherein the proximal sub-piece is electrically conducting.
4. A catheter as set forth in claim 1, wherein the distal sub-piece of the distal end piece has at least one change in outside diameter.
5. A catheter as set forth in claim 1, wherein the sleeve has at least one change in inside diameter.
6. A catheter as set forth in claim 1, wherein the proximal part of the distal sub-piece projects into the distal part of the proximal sub-piece and wherein the distal sub-piece is connected to the proximal sub-piece by a force-locking connection, a positively locking connection or a joint involving intimate bonding thereof.
7. A catheter as set forth in claim 6, wherein the sleeve at least in part encloses the proximal sub-piece and the distal sub-piece of the distal end piece where the distal part of the proximal sub-piece encloses the proximal part of the distal sub-piece.
8. A catheter as set forth in claim 1, wherein the distal end piece forms a tip at a distal end of the catheter.
9. A catheter as set forth in claim 8, wherein the tip comprises polyphenylsulfone (PPSU) or polyetheretherketone (PEEK).
10. A catheter as set forth in claim 8, wherein the tip is provided with an anti-adhesion coating.
11. A catheter as set forth in claim 8, wherein the tip has a conical, trocar-shaped, cylindrical or spherical end face.
12. A catheter as set forth in claim 8, wherein the tip has an outside diameter matching an outside diameter of the flexible shaft tube and tapers downward at an angle of between 10° and 20° in a longitudinal direction of the catheter towards the distal end of the catheter.
13. A catheter as set forth in claim 1, further including a plastic hose in the lumen of the flexible shaft tube.
14. A catheter as set forth in claim 13, wherein the plastic hose and the flexible shaft tube comprise an electrically insulating material.
15. A catheter as set forth in claim 13, wherein the plastic hose comprises polyimide (PI).
16. A catheter as set forth in claim 13, wherein the flexible shaft tube is fluid-tightly connected to the plastic hose by welding, adhesive or by a press connection.
17. A catheter as set forth in claim 1, wherein the lumen is of a diameter of between 0.65 mm and 1.6 mm.
18. A catheter as set forth in claim 1, wherein the flexible shaft tube comprises polyetheretherketone (PEEK).
19. A catheter as set forth in claim 1, wherein the flexible shaft tube has at least one passage for passing the at least one electric line therethrough.
20. A catheter as set forth in claim 1, wherein the at least one electrode including the sleeve comprise at least two ring electrodes on the flexible shaft tube.
21. A catheter as set forth in claim 20, further including an annular insulator between the at least two ring electrodes.
22. A catheter as set forth in claim 21, wherein the annular insulator comprises polyetheretherketone (PEEK).
23. A catheter as set forth in claim 1, wherein the flexible shaft tube has a length between 600 and 2000 mm.
24. A catheter as set forth in claim 1, wherein the flexible shaft tube of the catheter has an outside diameter less than or equal to 5 mm.
25. A catheter as set forth in claim 1, further including a temperature sensor at a distal end of the catheter for detecting tissue temperature in proximity of the catheter or catheter temperature.
26. A catheter as set forth in claim 1, wherein the distal end piece has a central axial through bore forming a distal mouth opening.
27. A catheter as set forth in claim 26, wherein the distal mouth opening has a diameter of between 0.65 and 2 mm.
28. A catheter as set forth in claim 1, wherein the lumen is continuous between the proximal and distal ends of the catheter and the catheter has proximal and distal mouth openings, so that a guide wire can be introduced by way of the proximal mouth opening, advanced to the distal end through the lumen and issue again through the distal mouth opening.
29. A catheter as set forth in claim 1, wherein the distal end piece has a frustoconical configuration tapering at an angle of between 15 and 85 degrees.
30. A catheter as set forth in claim 1, wherein the catheter is closed at a distal end.
31. A catheter as set forth in claim 30, further including a cooling system with a proximal feed and discharge flow means for a cooling medium in the catheter.
32. A method for electrosurgical treatment of body tissue in the lumen of a hollow organ, including the steps of:
at least one electrode on a distal portion of the flexible shaft tube adapted to deliver high-frequency alternating current to body tissue surrounding the catheter during treatment, wherein the distal portion of the flexible shaft tube comprises the distal end of the flexible shaft tube, wherein said at least one electrode includes a sleeve in the form of a hollow cylinder which exerts a radially acting clamping force on the clamping connection, and at least one electric line which is electrically conductingly connected to the at least one electrode and which extends to a proximal end of the catheter;
d) advancing the catheter until at the least one electrode has reached a desired position; and
e) applying high-frequency AC voltage to the at least one electrode thereby delivering the high frequency alternating current to the body tissue surrounding the catheter during treatment.
33. A method for electrosurgical treatment of varicose veins, including the steps of:
at least one electric line which is electrically conductingly connected to the at least one electrode and which extends to a proximal end of the catheter;
b) opening a desired blood vein to create an opened vein;
d) pushing the catheter over the guide wire, introducing the catheter into the opened vein and advancing the catheter as far as the end of the opened vein;
e) providing a high-frequency AC voltage to the at least one electrode when the distal end of the catheter is correctly positioned thereby delivering the high frequency alternating current to the body tissue surrounding the catheter during treatment; and
f) retracting the catheter slowly in a proximal direction relative to the guide wire or together with the guide wire with a speed that is adapted to the geometry of the opened vein being treated and to the high-frequency AC voltage.
34. The method according to claim 33, whereby, before applying the high-frequency AC voltage to the at least one electrode, the method further comprising the step of expelling any blood within the opened vein using a cuff.
35. The method according to claim 33, whereby a cord is tensioned in parallel relationship with the catheter from a connecting element so that an end of the cord or a marked location on the cord outside the opened vein is approximately level with the at least one electrode within the opened vein.
36. The method according to claim 33, wherein speed of withdrawal of the catheter, the high-frequency AC voltage, or both are chosen depending on impedance between the at least one electrode and a counter-electrode.
37. A method for constriction or sclerosis of a fallopian tube, including the steps of:
at least one electrode on a distal end of the flexible shaft tube adapted to deliver high-frequency alternating current to body tissue surrounding the catheter during treatment, wherein the distal portion of the flexible shaft tube comprises the distal end of the flexible shaft tube, wherein said at least one electrode includes a sleeve in the form of a hollow cylinder which exerts a radially acting clamping force on the clamping connection, and
b) introducing a guide wire and thereafter the catheter by means of a hysteroscope or an endoscope from a uterus into the fallopian tube to be closed off;
d) providing a high-frequency AC voltage to the at least one electrode when a distal end of the catheter is correctly positioned thereby delivering the high frequency alternating current to the body tissue surrounding the catheter during treatment; and
e) withdrawing the catheter while delivering a high-frequency current within a defined distance so that a desired region contracts in respect of diameter and closes as a result.
38. A method for treating obstructive tumors in the region of the bile duct (ductus choledochus) in a patient, including the steps of:
b) introducing a flexible endoscope, gastroscope or duodenoscope through the patient, and positioning a distal end of the endoscope, gastroscope or duodenoscope in front of papilla of the duodenum;
c) introducing a guide wire into the bile duct and advancing the guide wire beyond a portion of the bile duct which is to be treated,
d) advancing the catheter over the guide wire until the at least one electrode of the catheter is within the portion of the bile duct that is to be treated; and
e) applying a high-frequency AC voltage to the at least one electrode thereby delivering the high frequency alternating current to the body tissue surrounding the catheter during treatment and thereby coagulating the body tissue surrounding the catheter during treatment.
39. The method according to claim 38, further including a step of fitting a stent into the bile duct in order to prevent renewed obstruction by fibrin precipitation phenomena.
US20090156981A1 true US20090156981A1 (en) 2009-06-18
US9750564B2 true US9750564B2 (en) 2017-09-05
WO2006017754A1 (en) 2004-08-05 2006-02-16 Vnus Medical Technologies, Inc. Methods and apparatus for coagulating and/or constricting hollow anatomical structures