RU2757526C1 - Locking stiletto device for extraction of endocardial electrode of electrocardiostimulator - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention intended for removal of infected, broken and prognostically dangerous endocardial electrodes previously implanted into the heart through a blood vessel. The device of locking stiletto for extraction of endocardial electrode of the pacemaker includes an electrode capture element consisting of movable and stationary parts relative to the electrode, a thrust, an actuator for moving the thrust and a loop handle located on proximal part of the thrust. According to the invention, a dynamometric device is fixed in rupture of the loop handle closer to the distal end and made in form of two cylindrical sleeves - external and internal, coaxially inserted into each other with possibility of free longitudinal movement relative to each other, with a compression spring located between the ends of cylindrical sleeves. Ends of each sleeve are facing in opposite directions. The thrust of the distal part of the loop handle is passed through a hole made in central part of the end face of the inner sleeve, laid inside the spring and rigidly fixed in the center of the end face of the outer sleeve. The thrust of the proximal part of the loop handle, at the junction with dynamometer device, is made with two ends that are inserted through holes in the end face of the outer sleeve, located symmetrically relative to its center, laid along the spring and rigidly connected to the edges of the inner sleeve. A scale with marks is applied to the wall of the inner sleeve, and a lock is fixed on the rod.

EFFECT: invention increases efficiency and safety of operation during extraction of endocardial electrode of pacemaker and minimizes injury to the patient, as well as excludes destruction of the electrode itself.

1 cl, 3 dwg

Description

The invention relates to medical technology, namely to cardiovascular surgery, and is intended to provide modern high-tech assistance to patients to remove infected, broken and prognostically dangerous endocardial electrodes previously implanted in the heart through a blood vessel.

Endovascular pacing electrode extraction is a relatively new practice. Extraction of the electrode should be carried out by safely separating it from the encapsulating fibrous tissue at the points of contact with the walls of the veins and the myocardium. The number of primary implantable pacemaker-electrode systems, both single-chambered and two-chambered, and three-chambered with two or more electrodes, is constantly growing, and, therefore, the need to replace systems increases, which is associated with the improvement or incompatibility of the stimulation systems, or with operational damage. electrodes. Complete removal of compromised (eg, infected), old, and dysfunctional endocardial leads becomes preferred. The presence of a non-functional foreign body in the lumen of blood vessels and heart cavities is a risk factor and can cause the development of various complications. The most common of these are infection, thromboembolism, and dysfunction of the tricuspid valve.

Known is a locking stylet device for the extraction of endocardial electrodes of a pacemaker (RU 2599684, cl. A61B 17/50, A61N 1/05, 2015), including an elongated cylindrical body, one end of which is designed to be placed in the lumen of the electrode, and the other end with the possibility of gripping, consisting of two parts, movable and fixed relative to the electrode, obtained by sectioning the body with an inclined plane passing through the bases of the cylindrical body, and made with the possibility of changing the cross-sectional area of the body by displacement relative to each other along adjacent inner surfaces when applied to the moving part tractive effort in the direction of the longitudinal axis of the electrode. The outer surface of the stationary part is made with notches. The end of the stylet, made with the possibility of gripping and provided with at least one element that acts as a handle with the possibility of its passage inside the devices for dissecting the peri-electrode joints.

However, when carrying out the procedure for removing the electrode, using the known device, there is no possibility of monitoring the loads, both on the locking stylet, on the electrode and, accordingly, on the human body. If the surgeon lacks experience, the risk of heart trauma and the development of serious complications increases.

The prototype of the invention is a locking stylet for extraction of an endocardial electrode of a pacemaker (RU 2720829, class A61B 17/00, publ. 05/13/2020), including a cylindrical body, one end of which is designed to be placed in the electrode lumen, consisting of a movable and a fixed part relative to electrode, a rod, an actuator for moving the rod and a looped handle located at the proximal end of the rod. The outer surface of the distal end of the cylindrical body, from the side of its placement in the lumen of the electrode, is made beveled to form an outer conical surface on which a cap-grip with longitudinal slots is located, rigidly connected to the rod. The inner edge of the cap-grip is made beveled with the formation of an inner tapered surface that coincides in size and shape with the outer tapered surface of the distal end of the cylindrical body. The actuator for moving the thrust is made in the form of a screw pair including a proximal stop rigidly connected to the thrust and a nut located between the proximal stop and entering into a screw connection with a distal stop rigidly connected to the movable part of the cylindrical body.

The disadvantages of the known device include the lack of the ability to control the effort carried out by traction during the operation to remove the endocardial electrode of the pacemaker, which can lead to negative consequences during the operation. This can be a rupture of the electrode, as well as an excessive force on the heart at the point of fixation of the endocardial electrode, because the electrode grows to the walls of the vessels with its outer side, and the electrode is fixed behind the inner spiral of the electrode, and if the force is exceeded, the inner spiral of the electrode may be torn off, which will entail difficulties in removing the remaining electrode.

The problem to which the invention is directed is the creation of a simple and convenient locking stylet device, with the ability to provide visual control over the effort during the extraction of the endocardial pacemaker electrode.

The technical result of the invention is to improve the efficiency and safety of the operation during the extraction of the endocardial electrode of the pacemaker and to minimize injury to the patient, as well as to exclude the destruction of the electrode itself.

The problem posed and the specified technical result are achieved due to the fact that the locking stylet device for extracting the endocardial electrode of the pacemaker includes an electrode gripping element consisting of movable and stationary parts relative to the electrode, a rod, an actuator for moving the rod and a loop handle located on the proximal part of the rod. According to the invention, in the gap of the loop handle, closer to the distal end, a dynamometric device is fixed, made in the form of two cylindrical sleeves - external and internal, coaxially inserted into one another with the possibility of free longitudinal movement relative to each other, with a compression spring located between the ends of the cylindrical sleeves ... The ends of each sleeve are facing in opposite directions. The pull of the distal part of the looped handle is passed through the hole made in the central part of the end of the inner sleeve, is laid inside the spring and is rigidly fixed in the center of the end of the outer sleeve. The rod of the proximal part of the loop handle, at the junction with the torque device, is made with two ends, which are inserted through the holes in the end of the outer sleeve, located symmetrically relative to its center, laid along the spring and rigidly connected to the edges of the inner sleeve. On the wall of the inner sleeve there is a scale with marks, and on the rod, a retainer is fixed.

The torque device is installed at a distance of 50 mm from the distal end of the loop handle.

The installation of a torque device allows you to control the effort in the process of removing the endocardial electrode of the implanted pacemaker, minimizing the traumatic effect on the patient. Thus, the safety of the electrode extraction procedure increases, the likelihood of myocardial tearing at the fixation point decreases, and the dynamometric device does not allow exceeding the destruction limit of the electrode itself.

A dynamometric device made in the form of two cylindrical outer and inner sleeves, coaxially inserted into one another, with the possibility of free movement relative to each other in the longitudinal direction, with the ends of each sleeve facing in opposite directions - ensures the compactness of the dynamometric device and visualization of the applied force during traction of the electrode ...

Installing a compression spring inside the torque device, between the ends of the cylindrical sleeves, allows you to control the load on the tool when removing the electrode. When a tensile force occurs, the spring installed inside the torque device clamped between the ends of the cylindrical sleeves begins to compress in proportion to the tensile force. In this case, the inner sleeve begins to move inside the large sleeve. During the extraction of the electrode while pulling on the locking stylet, there is a gradual increase in the applied force, controlled by the spring. At the same time, the fibrous capsule begins to collapse at the point of electrode fixation in the heart cavity (in the right atrium or right ventricle) and when an effort of 1.5 - 2 kgf is reached, the electrode is detached from the fibrous capsule. Exceeding the force of more than 2 kgf can lead to rupture of the heart wall.

The rigid connection of the loop handle and the rod with the ends of the inner and outer sleeves ensures the stability of the entire device during the electrode removal procedure.

The application of a scale with marks on the wall of the inner sleeve of the torque device allows one to estimate at a specific point in time the force applied to extract the electrode. When the maximum force is reached, determined by the design of the locking stylet and the threshold of pain (uncomfortable) sensations for the patient, the “MAX” mark is aligned with the end face of the outer sleeve.

The invention is illustrated by drawings, where Fig. 1 is a general view of a locking stylet device for extraction of an endocardial pacemaker electrode; in fig. 2 is a diagram of the structure of the dynamometer device at minimum load, FIG. 3 is a diagram of the structure of the load cell at maximum load.

The locking stylet device for the extraction of the endocardial electrode of the pacemaker has a working length of 430 mm to 650 mm for the possibility of passing through the internal lumen of the endocardial electrode to its distal part. The maximum length of the endocardial electrode is 580 mm. The length of the electrode with the connector part removed is about 400 mm. The torque gauge diameter is 2.5 mm. In the free state, the length of the dynamometer is 40 mm, while in the compressed state with a load of 2 kgf (20 N), the length of the dynamometer is 30 mm. These dimensions are chosen in such a way that the locking stylet with a dynamometric device can be easily used in a set with other tools used for removing electrodes, such as a telescopic dilator, mechanical dilator. These instruments are often used in tandem with a locking stylet by the anti-traction method, when the stylet is pulled from the inside by the distal end of the electrode, and from the outside along the body of the electrode, a telescopic dissection of fibrous tissue is provided, which holds the electrode in the vein cavity.

The locking stylet device with a dynamometric device for the extraction of the endocardial electrode of the pacemaker includes an electrode gripping element 1, consisting of a movable and stationary parts relative to the electrode, a rod 2, an actuator 3 for moving the rod 2 and a loop handle 4, consisting of a proximal part 5 and a distal part 6, between which a dynamometric device is fixed, which is located closer to the active part of the locking stylet, at a distance of 50 mm from the distal part 6. The dynamometric device is made in the form of two outer sleeves 7 and an inner sleeve 8. The inner sleeve 8 is inserted into the outer sleeve 7 with the possibility of free longitudinal moving relative to each other. The end face 9 of the sleeve 7 is turned in the opposite direction relative to the end face 10 of the sleeve 8. A compression spring is installed between the ends 9 and 10. fixed in the center of the end face 9 of the outer sleeve 7. The proximal part 5 of the loop handle 4, at the junction with the torque device, is made with two ends 13, which are inserted through the holes 14 in the end face 9 of the outer sleeve 7, located symmetrically relative to the center of the end face 9, are laid along springs 11 and are rigidly connected to the edges of the inner sleeve 8. A scale with marks is applied to the wall of the inner sleeve 8, and a lock 15 is attached to the distal end 6 of handle 4.

The device of the locking stylet for the extraction of the endocardial electrode of the pacemaker operates as follows.

In the absence of a tensile force, the compression spring 11 inside the sleeves 7 and 8 has a maximum length due to the position of the latch 15 on the distal part 6 of the loop handle 4. In this case, the spring 11 has a slight preliminary compression. The latch 15, located on the distal part 6 of the loop handle 4, also plays the role of a part that prevents the dynamometer from falling apart. When the endocardial electrode is extracted, a tensile force arises in the structure of the locking stylet, which is the same along the entire length of the instrument, including on the loop handle 4, where the torque device is located.

The force at which the electrodes are extracted only with the locking stylet, as a rule, does not exceed 2 kgf (20N). When a tensile force occurs, the spring 11, installed inside the sleeves 7 and 8, clamped between the ends 9 and 10, begins to compress in proportion to the tensile force. In this case, the inner sleeve 8 begins to move inside the outer sleeve 7. To visualize the process, a scale with markers is applied to the cylindrical surface of the inner sleeve 8, with the help of the position of which at a particular moment in time it is possible to estimate the force applied to extract the electrode. When the maximum force is reached, determined by the design of the locking stylet and the threshold of pain (uncomfortable) sensations for the patient, the “MAX” mark is aligned with the edge of the outer sleeve 7.

Control over the force during the extraction of the endocardial electrode of the pacemaker allows you to exclude the excess of the destruction limit of the tool for removing the electrode, to exclude the excess of the destruction limit of the most removed endocardial electrode, and also to use this device for educational purposes to acquire the skills of feeling the load when removing the electrodes.

At present, the device of a locking stylet for the extraction of the endocardial electrode of a pacemaker with a dynamometric device is at the stage of a preliminary design, manufacturing and testing of material models.

Claims (2)

1. The device of the locking stylet for the extraction of the endocardial electrode of the pacemaker, including the electrode gripping element, consisting of a movable and fixed parts relative to the electrode, a rod, an actuator for moving the rod and a loop handle located on the proximal part of the rod, according to the invention, at the gap of the loop handle, closer to its distal end, a dynamometer device is fixed, made in the form of two cylindrical sleeves - external and internal, coaxially inserted into one another with the possibility of free longitudinal movement relative to each other, with a compression spring located between the ends of the cylindrical sleeves, with the ends of each sleeve facing opposite sides, the pull of the distal part of the loop handle is passed through the hole made in the central part of the end of the inner sleeve, is laid inside the spring and rigidly fixed in the center of the end of the outer sleeve, the pull of the proximal part of the loop of the loop is at the junction with a torque device, made with two ends, which are inserted through holes in the end of the outer sleeve, located symmetrically relative to its center, laid along the spring and rigidly connected to the edges of the inner sleeve, in addition, a scale with marks is applied to the wall of the inner sleeve, and on the rod the retainer is fixed. 2. The device according to claim. 1, characterized in that the torque device is installed at a distance of 50 mm from the distal end of the loop handle.

Images