RU2795730C1 - Stent graft compression device to move the compressed stent graft into a delivery device - Google Patents

Abstract

FIELD: cardiovascular surgery.

SUBSTANCE: device for compressing the stent graft in order to move the compressed stent graft into the delivery device contains two rings connected by threads that form a gap in the space between the threads. One of the rings has a smaller diameter than the other. The ring with a larger diameter has an inner recess, and the ring with a smaller diameter is designed to be inserted into the inner recess of the ring with a larger diameter. The rings are made with the ability to rotate relative to each other in opposite directions in such a way that the rings approach each other, ensuring the insertion of a ring with a smaller diameter into the inner recess of the ring with a larger diameter, and the gap in the space between the threads narrows, providing compression of the stent graft inserted into the gap. The rings are equipped with jaws to ensure their rotation beyond the said jaws.

EFFECT: possibility to compress the stent graft to the required diameter in order to move the compressed stent graft into the delivery device.

3 cl, 7 dwg

Description

Technical field

The invention relates to the field of cardiovascular surgery. It can be used in specialized departments of cardiovascular surgery.

State of the art

Endovascular treatment of aortic diseases is aimed at exclusion from the circulation of the affected area of the aorta by implanting covered stent grafts in the affected area in order to prevent further expansion and rupture of the aorta. Aortic arthroplasty is an effective treatment for aortic lesions; currently, aortic arthroplasty combines such advantages over open surgery as low invasiveness of the intervention, a short recovery period after the intervention, a lower risk of intraoperative complications and mortality. A significant advancement and simplification of endovascular surgery was the introduction of devices for percutaneous suturing on the market, which made it possible to perform complex interventions under local anesthesia. All this has led to the fact that endovascular treatment of aortic diseases has become the method of choice in patients from high surgical risk groups. However, one of the main and main disadvantages of endovascular treatment of lesions of the aorta and its branches is the covering of the lateral branches that were involved in the affected area. In order to maintain antegrade blood flow along the covered branches, before aortic arthroplasty it is necessary to perform bypass operations using the traditional surgical method (the so-called "hybrid" approach). Such surgical vascular interventions increase operational risks for the patient and often delay the implementation of the main endovascular stage. One of the significant disadvantages of the hybrid approach in aortic arthroplasty is a high risk of complications and a long recovery period after the first stage of open surgery, and in some cases may be contraindicated in patients from high-risk groups. Over the past decades, endovascular technology for exclusion of an aortic aneurysm from the main bloodstream has undergone significant evolutionary changes and improvement and is currently an alternative to open surgical interventions.

Thanks to the appearance of fenestrated, the word "fenestration" comes from the Latin fenestration - to provide windows, holes, and branched stent grafts, endovascular treatment of more complex anatomical variations of aortic aneurysms with the inclusion of lateral branches became possible. The use of fenestrated endografts was first introduced in 1996 [1]. However, after several decades, such endografts are used extremely rarely and could not compete with less physiological linear prostheses. There were several reasons for this.

The disadvantage of branched stent grafts is the extremely low availability, due to the need for individual manufacturing of the device, taking into account the individual characteristics of the patient's anatomy, requiring a long wait, which in turn increases the cost, thereby limiting their introduction into wide clinical practice. In turn, these shortcomings make such devices of little use in emergency situations, especially in acute aortic syndrome. Cook medical has proposed a thoracoabdominal endovascular graft Zenith t-Branch, Zenith® Fenestrated Graft. The disadvantages of such systems also include an individual ordering system, which increases the waiting time for finished copies and an extremely high cost. The endovascular technique using parallel endografts to maintain blood flow through the branches of the aorta is a well-known alternative to branched and fenestrated stent graft components [2]. However, this technique is also not often used due to anatomical features.

In the mid-2000s, the medical community returned to the topic of the need to maintain antegrade blood flow through the covered arteries in one way or another. Attempts have been made to introduce into practice the individual modification of existing grafts in relation to the anatomy of the patient. Dr. Gustavo S. Oderich covered in detail the topic of endograft modification, namely the creation of fenestrations and cuffs to solve the problem of maintaining patency along the side branches, but first of all, these modifications concerned the platform [3].

The proposed methods are based on the principle of preliminary individual fenestration of the opened stent-graft, followed by compression and folding it into a delivery device. Compression and return of the stent graft to the delivery device was performed either manually without the use of auxiliary devices, or using a sterile tourniquet, which alternately tightened the crowns of the stent graft and led into the delivery device, which complicated and delayed the procedure for individual modification of the stent graft, and also increased number of marriages in the end. Thus, the problem of compressing the stent graft and returning it to the delivery device with a high level of technical success is still relevant and requires further development in the search for the most optimal technique. The prototype [4], which mentions the collapser of the aortic bioprosthesis.

Disclosure of the essence of the invention

The essence of the invention is to ensure compression of the stent graft to the required diameter in order to move the compressed stent graft into the delivery device. The procedure for moving the stent-graft into the delivery device is carried out as follows: the opened sten-graft is inserted with its proximal end into the disk of the proposed collapser device, then the movement of two composite disks of the collapser relative to each other by the jaws is performed. The movement of two composite disks entails a decrease in the diameter of the ring formed from the threads located in the collapser. There is a compression of the stent-graft located in the resulting ring of filaments of the collapser. The compressed stent graft is then inserted into the delivery device. A similar procedure is performed with all open sections of the stent graft, one or more collapsers, until it is fully positioned in the delivery device. The device has a flat mobile design, without a platform, which allows you to visually control the position of the stent graft and fix the distal part when the system is loaded. The advantage is to work with the device with two fingers.

Brief description of the drawings

On FIG. 1 implementation of the proposed device. Between rings 1 and 2, made of plastic, threads 3 are stretched, attached to rings 1 and 2. There is a gap 4 inside the resulting cylinder.

On FIG. 2 shows the narrowing of the lumen 4 when the rings rotate in opposite directions. Clearance 4 decreases and it is possible to compress the object 2 placed inside the decreasing gap 4 by the surrounding threads 3. This option has a number of disadvantages, such as the need to hold the device with both hands, the need to keep the threads taut all the time.

On FIG. 3 is an embodiment of the device in which rings 5 and 6 are connected by threads 3. Rings 5 and 6 have branches 7. Ring 5 has a smaller diameter than ring 6. When ring 5 is inserted into the inner recess 8 of ring 6, ring 5 can rotate inside rings 6. On the ring 5, perpendicular to the plane of the circle, there are holes 9, which serve to insert threads 3 into them and fasten them, for example, with glue. The total number of holes is eight, they are evenly spaced around the circumference of the ring 5. The other ends of the threads 3 are attached to the holes 9 located on the inner surface of the rim of the ring 6. The holes 9 are evenly spaced around the circumference, they are located along the extensions of the radii drawn from the center of the ring 6. The total number holes eight they are evenly spaced around the circumference. Threads 3 are attached to the holes 9 located on the inner surface of the rim of the ring 6, coming from the holes 9 on the ring 5. With the mutual counter-rotation of the rings 5 and 6, behind the jaws 7, the gap 4 in the space between the threads 3 will narrow, similar to the narrowing process in FIG. 2. Rings 5 and 6 will approach each other, and when approached, ring 5 will be inserted into recess 8 of ring 6. Holes 9 on ring 5 and the threads inserted into them will not be overlapped by ring 6 when inserting ring 5 into ring 6. After inserting the ring 5 into the recess 8 of the ring 6, the ring 5 can be pressed against the ring 6 by means of the flange ring 10 put on the screws 11 located on the ring 6 perpendicular to the plane of the circle. The flange ring 10 can be fixed on the screws 11 by means of nuts screwed on the screws 11 having a thread 12. The screws 11 are inserted into the flange ring in the holes 13. After fixing the flange ring 10, the rings 5 and 6 have the possibility of mutual rotation of the branch 7 limited by free play , rings 5 between screws 11.

On FIG. 4 the device is assembled, with the ring 5 inserted into the ring 6 and their mutual pressing by the flange ring, put on the screws and secured with nuts. In this drawing, only part of the screw 11 is visible in the form of a head, the nut is screwed on the other side of the screw, which is not visible in the drawing. Branches 7, both rings 5 and 6 are divorced and the gap 4 between the threads 3 is maximum. In this position, it is possible to insert a physical body into it that needs to be compressed, for example, a stent graft. The holes 9 of the ring 5 inserted into the ring 6 are not covered by the ring 6. The threads inserted into the ring 6 are fixed inside the channels 14 formed by the holes 9 of the rim of the ring 6. The flange ring in the figure is on the opposite side and is not shown in the figure. Threads 3 can also be fixed in the channels 14 by means of glue.

On FIG. 5 branches 7 of both rings are brought together, and the gap 4 between the threads 3 is minimal. In this position, the physical body, which will be previously inserted into the lumen 4, will be compressed by threads 3, for example, a stent graft.

On FIG. 6 is a side view of the movable ring 5 inserted into the ring 6. The jaw 7 has a smaller thickness than the ring 5 so as not to interfere with the contact of the surface 15 of the ring 5 with the surface of the recess 8 of the ring 6.

On FIG. 7 shows the device in the state of maximally shifted jaws 7 towards each other, the lumen is minimal and the deployed stent graft 16 is compressed and placed in the delivery device 17.

The implementation of the invention The advantage of the proposed device is the simplicity of the proposed design. For the manufacture of the proposed device, you can use any existing materials and threads, as an option, you can use various plastics and synthetic or silk threads.

Several prototypes were made using 3D printed parts and tested on aortic stent grafts. All cases of compression by the proposed invention and positioning of the stent graft in the delivery device, and then the opening of the modified stent grafts were successful.

The branch is one of the two core parts of lever tools.

A collapser is a device - an apparatus for compressing the prosthesis before implantation in order to reduce the diameter. [4].

Information sources:

1. O. Ehsan, D. Murray, F. Farquharson, F. Serracino-Inglott Endovascular repair of complex aortic aneurysms Ann Vase Surg, 25 (2011), pp.716-725.

2. Branched and fenestrated stent grafts for endovascular repair of thoracic aortic aneurysms Timothy A.M. Chuter, DM. JOURNAL OF VASCULAR SURGERY February Supplement 2006.

3. Zenith (Cook medical). (Physician-Modified vs Off-the-Shelf Fenestrated and Branched Endografts: Is This a Fair Comparison? Gustavo S. Oderich, MD1 Journal of Endovascular Therapy 2016, Vol.23(1) 110-114).

4. Patent No. 173037 RU.

Claims (3)

1. A device for compressing a stent graft in order to move the compressed stent graft into a delivery device, characterized in that it contains two rings connected by threads forming a gap in the space between the threads, while one of the rings has a smaller diameter than the second, and a ring with a larger diameter has an inner recess, and a ring with a smaller diameter is made with the possibility of insertion into the inner recess of a ring with a larger diameter, the rings are made with the possibility of rotating relative to each other in opposite directions so that the rings approach each other, ensuring the insertion of a ring with a smaller diameter into an internal recess of the ring with a large diameter, and the lumen in the space between the threads narrows, providing compression of the stent graft inserted into the lumen, while the rings are equipped with branches to ensure their rotation by the said branches. 2. Collapser according to claim 1, characterized in that it contains a device for fixing the rings relative to each other. 3. The collapser according to claim 1, characterized in that the number of threads connecting the rings is 8.

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