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EP-4739386-A1 - IMPLANTATION ARRANGEMENT AND IMPLANTABLE MEDICAL DEVICE WITH TINES BEING PARTIALLY COATED WITH RADIOPAQUE MATERIAL

EP4739386A1EP 4739386 A1EP4739386 A1EP 4739386A1EP-4739386-A1

Abstract

An implantation arrangement (1) and an implantable medical device (5) such as an implantable leadless pacemaker are described. The implantation arrangement comprises an implantation tool (3) having a catheter (7) with a capsule (9) at its distal end for accommodating the implantable medical device. The implantable medical device comprises a housing (11) and plural elongate tines (13) extending from the housing (11) for fixing the implantable medical device at a patient's tissue. The tines are elastically bendable between a first configuration in which the tines are unstrained and a second configuration in which the tines are strained due to being elastically bent upon the implantable medical device together with its tines being accommodated within the catheter's capsule. Therein, in the second configuration, at least one first portion (15) of each tine (13) is elastically bent from a relaxed geometry into a strained geometry whereas at least one second portion (17) of each tine (13) remains in its relaxed geometry. Specifically, each tine comprises a radiopaque material (19) being applied exclusively to the second portion of the tine.

Inventors

  • HUGHES, DEVAN
  • Austin, Eric
  • Bosselmann, Marco

Assignees

  • BIOTRONIK SE & Co. KG

Dates

Publication Date
20260513
Application Date
20240614

Claims (11)

  1. 1. An implantation arrangement (1) including: an implantation tool (3) comprising a catheter (7) having a capsule (9) at its distal end for accommodating an implantable medical device (5), and an implantable medical device (5) comprising a housing (11) and plural elongate tines (13) extending from the housing (11) for fixing the implantable medical device (5) at a patient’s tissue, wherein the tines (13) are elastically bendable between a first configuration in which the tines (13) are unstrained and a second configuration in which the tines (13) are strained due to being elastically bent upon the implantable medical device (5) together with its tines (13) being accommodated within the catheter’s capsule (9), wherein, in the second configuration, at least one first portion (15) of each tine (13) is elastically bent from a relaxed geometry into a strained geometry whereas at least one second portion (17) of each tine (13) remains in its relaxed geometry, wherein each tine (13) comprises a radiopaque material (19) being applied exclusively to the second portion (17) of the tine (13).
  2. 2. The implantation arrangement () of claim 1, wherein, in the first configuration, the first portion (15) of each tine (13) being in its relaxed geometry is curved whereas, in the second configuration, the first portion (15) of each tine (13) being in its strained geometry is straightened.
  3. 3. The implantation arrangement () of claim 1, wherein, in the first configuration, the second portion (17) of each tine (13) is less curved than the first portion (15).
  4. 4. The implantation arrangement () of claim 1, wherein the second portion (17) of each tine (13) is straight.
  5. 5. The implantation arrangement () of claim 1, wherein the first portion (15) of each tine (13) extends proximal to the housing (11) whereas the second portion (17) of each tine (13) extends distally to the housing (11).
  6. 6. The implantation arrangement () of claim 1, wherein the radiopaque material (19) is applied to the tine (13) exclusively in an extension length forming less than distal-most 50% of an overall extension length of the tine (13).
  7. 7. The implantation arrangement () of claim 1, wherein the radiopaque material (19) is coated onto an outer surface (25) of the tine (13).
  8. 8. The implantation arrangement () of claim 1, wherein the radiopaque material (19) is applied as a layer (21) having a thickness of between 1 pm and 100 pm.
  9. 9. The implantation arrangement () of claim 1, wherein the tines (13) are made with a shape-memory base material (27) and wherein the radiopaque material (19) has a higher X-ray absorption than the base material (27).
  10. 10. An implantable medical device (5), comprising a housing (11) and plural elongate tines (13) extending from the housing (11) for fixing the implantable medical device (5) at a patient’s tissue, wherein the tines (13) are elastically bendable between a first configuration in which the tines (13) are unstrained and a second configuration in which the tines (13) are strained, wherein each tine (13) in its first configuration comprises a first portion (15) proximal to the housing (11), the first portion (15) being strongly curved, and a second portion (17) distal to the housing (11), the second portion (17) being one of straight and less curved than the first portion (15), wherein each tine (13) comprises a radiopaque material (19) being applied exclusively to the second portion (17) of the tine (13).
  11. 11. The implantable device of claim 10, wherein each tine (13) comprises the radiopaque material (19) applied to the tine (13) exclusively in an extension length forming less than distal-most 50% of an overall extension length of the tine (13).

Description

IMPLANTATION ARRANGEMENT AND IMPLANTABLE MEDICAL DEVICE WITH TINES BEING PARTIALLY COATED WITH RADIOPAQUE MATERIAL The present invention relates to an implantable medical device and an implantation arrangement comprising such medical device. Implantable medical devices (IMD) may be implanted at or in a body of a patient e.g. for supporting and/or monitoring physiological functions. For example, a pacemaker may be implanted for stimulating cardiac activity of the patient. Particularly, miniaturized implantable leadless pacemakers (ILP) have been developed which may be implanted directly into a cardiac chamber of a patient’s heart such that an electrode contacts cardiac tissue. Accordingly, cardiac activity may be stimulated by applying electric pulses via the electrode. Generally, the IMD is to be arranged and fixed within the body at a predetermined location in order to enable fulfilling its intended function. For example, the ILP is to be arranged and fixed within the carrier chamber such that its electrode reliably remains in electric contact with cardiac tissue despite any motions of the heart. For such purpose, IMDs typically comprise a housing and a fixation mechanism. The housing typically accommodates components such as a controller for controlling functions of the IMD and an energy source such as a battery. The fixation mechanism is configured for correctly and reliably fixing the housing in relation to the patient’s body. Generally, during an implantation procedure, an implantation arrangement is used for, on the one hand, introducing the IMD into the patient’s body and forwarding it to an intended implantation site and for, on the other hand, suitably activating the fixation mechanism of the IMD for fixing it at tissue at the implantation site. Such implantation arrangement typically comprises an elongate catheter including a capsule at its distal end, wherein the IMD may be accommodated within the capsule during the implantation procedure and may be ejected from the capsule for fixing it at the implantation site. In a common approach, the fixation mechanism is implemented using plural elongate tines extending from the housing of the IMD. Such tines are generally elastically bendable. Accordingly, during the implantation procedure, the IMD may initially be comprised within the capsule of the catheter with the tines at the IMD being arranged in a space saving configuration within the capsule. In such state, the tines are elastically deformed such that they fit into the capsule. Accordingly, in such configuration, the tines are mechanically strained. Upon having reached the intended implantation site, the IMD together with its tines is ejected from the capsule and, accordingly, the pre-strained tines may relax from their previous strained geometry to a relaxed geometry. During such relaxation, distal tips of the tines perform a motion which enables distal end portions of the tines to penetrate and be anchored within the patient’s tissue. For example, tines at an iPL may be anchored with their distal end portions in cardiac tissue within the patient’s heart. Subsequently, a so-called tug test is typically applied. Therein, forces such as pulling forces are applied via the catheter to the IMD and it is checked whether the fixation of the IMD is correctly established. Particularly, it may be checked whether the tines of the fixation mechanism are correctly introduced and held within adjacent tissue. During the implantation procedure and, particularly, during the tug test, a position of the IMD and of its components generally has to be observed and monitored. For such purpose, x-ray techniques such as computed tomography are generally used. Therein, at least portions of the IMD and/or of the entire implantation arrangement are visible on x-ray images due to some radiopaque material being comprised therein. However, it has been recognized that at least in some cases it may be difficult to correctly check the positioning and fixation of tines at an IMD using x-ray techniques. Particularly, for example a position and/or extension of the tines within cardiac tissue may hardly be visible in x-ray images upon the IMD being implanted into a heart which is continuously beating and which, furthermore, is at least partly “hidden” behind ribs also having some x- ray absorption. It is an object of the present invention to provide an implantation arrangement and an implantable medical device which enable improving an implantation procedure. Particularly, it may be an object to improve monitoring the tines at the IMD during the implantation procedure. Furthermore, it may be an object to provide such improvement with high reliability, long-term durability and/or at relatively low costs. Such objects may be met with the subject-matter of the independent claims. Advantageous embodiments are defined in the dependent claims as well as the corresponding specification and figures. According to a first aspect, an implant