Abstract: The preferred embodiment provides apparatus for ablating a vessel by generating heat within a vessel to cause blood clotting to occlude the vessel. The apparatus includes an electrically resistive element at the distal end of the apparatus, the resistive element being uncoated and therefore in bare form. An alternating current supply feeds electrical current through the resistive element to cause heating of the element and surrounding blood or tissue. The alternating current power supply preferably is balanced about a centre point so as to create a net sum of alternating pulses of zero. It has been found that the supply of alternating current to the resistive element reduces or eliminates corrosion of the resistive element in blood as the resistive element is heated. Use of conductive coatings for a sacrificial anode can be avoided.

Abstract: A guide wire includes a plurality of segments which can interlock rotatably relative to one another. A locking element extends through a lumen of the segments. When the locking element is in an unlocked condition the segments are able to rotate relative to one another. In this mode, the guide wire is very flexible. The locking element can be tightened to cause the segments to lock in engagement with one another and to fix the guide wire in position. In practice, the guide wire can be fixed in a curved or bent configuration, which enables the guide wire to provide a rigid support for a microcatheter or other element of an introducer assembly. The guide wire therefore can exhibit both extreme flexibility and stiffness.

Abstract: An implantable medical device includes an expandable support structure, which may be a stent. In the example shown, the device is a vascular plug and includes a twisted occluding sleeve held within the stent, which closes the lumen through the stent. At a distal end of the stent, there is provided a guide tip made of a resilient material, which includes a plurality of separable legs coupled to a central hub. The legs extend radially outwardly when the device is in its radially expanded configuration, providing an open passage to the medical device. This structure of combined medical device and expandable guide tip enables the omission of a conventional dilator tip of an introducer assembly and allows vascular plugs and similar devices to be deployed over-the-wire and with the assistance of a dilator tip, while avoiding having to pull the dilator tip through the deployed medical device after implantation.

Abstract: The present disclosure provides for a device and methods of use to endoluminally ablate and/or occlude a body vessel using a radiofrequency (“RF”) signal. The device has two conductive elements or electrodes that form an electrical circuit and are operable to create an electrical field. The electrical field ablates the body vessel, forming an occlusion.

Abstract: The present disclosure provides for a device and methods of use to endoluminally ablate and/or occlude a body vessel using a radiofrequency (“RF”) signal. The device has two conductive elements or electrodes that form various electrical circuits, and the two conductive elements are operable to create an electrical field. The electrical field ablates the body vessel, forming an occlusion.

Abstract: The present disclosure provides for a device and methods of use to endoluminally ablate and/or occlude a body vessel using a current to perform resistive heating. The device includes a resistive coil, which in some embodiments has a portion with a first, higher average pitch which can be electrified, and a second, lower average pitch, which is not electrified but aids in relieving mechanical stress. The device may have a support, which may be a wire guide, around which the coil is disposed. The device may provide a minimal diameter and flexibility for navigation of tortuous vessels.

Abstract: A guide wire includes a plurality of segments which can interlock rotatably relative to one another. A locking element extends through a lumen of the segments. When the locking element is in an unlocked condition the segments are able to rotate relative to one another. In this mode, the guide wire is very flexible. The locking element can be tightened to cause the segments to lock in engagement with one another and to fix the guide wire in position. In practice, the guide wire can be fixed in a curved or bent configuration, which enables the guide wire to provide a rigid support for a microcatheter or other element of an introducer assembly. The guide wire therefore can exhibit both extreme flexibility and stiffness.

Abstract: The present disclosure provides for a device and methods of use to endoluminally ablate and/or occlude a body vessel using a radiofrequency (“RF”) signal and a current to perform resistive heating. The device may have a RF mode and a resistive mode, and may perform each mode in sequential order until the vessel is fully occluded. The device further comprises a control unit to operate the device in its various modes. The device may be provided in a system including an occlusive element, such as a balloon catheter, to prevent blood flow through the ablation/occlusion site.

Abstract: The preferred embodiment provides apparatus for ablating a vessel by generating heat within a vessel to cause blood clotting to occlude the vessel. The apparatus includes an electrically resistive element at the distal end of the apparatus, the resistive element being uncoated and therefore in bare form. An alternating current supply feeds electrical current through the resistive element to cause heating of the element and surrounding blood or tissue. The alternating current power supply preferably is balanced about a centre point so as to create a net sum of alternating pulses of zero. It has been found that the supply of alternating current to the resistive element reduces or eliminates corrosion of the resistive element in blood as the resistive element is heated. Use of conductive coatings for a sacrificial anode can be avoided.

Abstract: A system for controlling deployment of an implantable medical includes an implantable medical device and a gripper mechanism. One or both of the medical device and the gripper mechanism are made from a shape-memory alloy material having a temperature at which the material will transition from a martensite state to an austenite state. The shape-memory alloy material has a transition temperature that is higher than a normal body temperature and a wide hysteresis band, with a temperature at which the material transitions back into the martensite state being below a normal body temperature. The medical device will expand or change shape upon being heated by a current passing therethrough, but will not transition into its remembered shape until such current is applied.

Abstract: A medical ablation system includes an elongate element to be inserted endoluminally into a patient's vessel and includes at its distal end a pre-heating element and an ablation element. The system provides pre-heating of, for example, blood to a first threshold temperature above body temperature but below ablation temperature; and then a second heating stage provided by the ablation element. Pre-heating reduces the amount of energy required to effect ablation, resulting in more focussed embolization with a higher proportion of energy delivered to the area in a more controlled manner. The arrangement can reduce the amount of damage to surrounding tissues and organs.

Abstract: RF ablation system includes a catheter having a lumen therein and a first electrode. Second electrode is disposed around the catheter proximate the distal end of the catheter and spaced from the first electrode by an insulating spacer which may be a part of the catheter or a sleeve on the first electrode. The first electrode is able to slide in and out of the catheter to vary the exposed length of the first electrode and as a result to alter the energy density at the first electrode in order to exhibit different heating effects. Control unit controls current through the electrodes and also the exposed length of the first electrode. The second electrode has a surface area at least twice that of the first electrode. Consequently, negligible heat is generated at the second electrode and therefore no blood clotting or other ablation material is formed over the catheter.