WO2014128313A1

WO2014128313A1 - Device for supporting and positioning occlusive elements

Info

Publication number: WO2014128313A1
Application number: PCT/ES2013/070109
Authority: WO
Inventors: Carlos CASTAÑO DUQUE
Original assignee: Castaño Duque Carlos
Priority date: 2013-02-21
Filing date: 2013-02-21
Publication date: 2014-08-28

Abstract

The invention relates to a device for supporting and positioning occlusive coil or spiral-type elements for the endovascular embolisation of aneurysms, said device comprising an essentially tubular structure (1) in the form of a network or mesh of threads (2) of a surgically appropriate material, said tubular structure (1) having a distal end (3) and a proximal end (4), the distal end (3) corresponding to the end of the tubular structure (1) inserted into the aneurysmal sac (10) and the proximal end (4) corresponding to the part of the tubular structure opposing the aneurysm, where the distal (3) and the proximal (4) ends of the tubular structure (1) are integrally connected with structural continuity via a narrowing or a neck (6), the distal end (3) having a funnel or trumpet (5) shape stretched in relation to the diameter of the tubular structure (1) and deployable towards the inside of the aneurysm.

Description

SUPPORT DEVICE AND PLACEMENT OF OCLUSIVE ELEMENTS

DESCRIPTION OBJECT OF THE INVENTION

In general, the present invention relates to a support device and placement of occlusive elements, such as coils or spirals of the type commonly used in endovascular aneurysm embolization. The device of the invention is intended for the placement and anchoring of such occlusive elements, for example, in wide-necked intracranial aneurysms, mainly located in vascular bifurcations.

BACKGROUND OF THE INVENTION

Currently, embolization is the treatment usually applied for the treatment of aneurysms and other malformations of blood vessels in the brain due to its minimally invasive nature since it has shown better results than surgical treatment (International Subarachnoid Aneurysm Trial (ISAT) of neurosurgical clipping versus endovascular coiling in 2143 patients with ruptured intracranial aneurysms: a randomized trial, Lancet 2002; 360: 1267-74). In this regard, an aneurysm is a bulge or sac that develops in an artery because the vessel wall is weak. A bulky aneurysm in the brain can compress the surrounding nerves and brain tissue, resulting in neurological focality, cranial nerve paralysis or endocranial hypertension that manifests with headache, nausea and vomiting. If the cerebral aneurysm ruptures, due to an opening in the wall, an extracranial blood (hemorrhage) occurs intracranial, which constitutes a very serious pathology that can cause significant neurological sequelae or death in a high percentage.

Briefly, in an endovascular embolization procedure, guided by images obtained with X-rays, a microcatheter is inserted through the skin into an artery and sent to the aneurysm sac, inserting one or more coils through the microcatheter inside, where they are anchored. The body responds by producing a thrombosis and subsequent scarring around the coil, which helps obstruct the flow of blood into the aneurysm, thus preventing it from rupturing. However, it is known that the effect of embolization with coils varies according to the size and shape of the aneurysm. Thus, embolization of small aneurysms with small necks has better results than the corresponding embolization of large or giant aneurysms with wide necks. Therefore, in the particular case of intracranial wide neck aneurysms, other technologies such as embolization with protective balloon (Remodeling), colloid retention coils (Trispan) or with placement of a stent at neck level have been incorporated aneurysm

While the coils were shown to be effective in small aneurysms with defined small necks and continents, since the flow within the aneurysm was interrupted by major obstruction, what prompted the intra-aneurysmal thrombus, the aneurysms of larger with broad and non-continental necks, they presented greater difficulty for a complete obliteration of the neck, with risks of migration of the coils towards the light of the carrier artery (José Tevah C, "Endovascular treatment of cerebral aneurysms: its beginnings 30 years and its current development ", Chilean Journal of Radiology. Vol. 9, n ° 2, year 2003; pp. 78-85).

To avoid the risk of coils or spirals migrating to the carrier artery as a result of "dragging" the same blood flow because the aneurysm neck is larger than the diameter of the coils themselves, the controlled detachment micro-spirals were designed, where the spiral is attached to the mandrel that pushes it along the microcatheter, and can be released at the operator's discretion only when it is positioned and / or repositioned in a stable situation, as is the case of the I DC system, Interlockable Detachable Coil, of Target Therapeutics, which allows the coil to be advanced and removed inside the aneurysm before its definitive detachment (Cekirge HS, Saatci I., Firat MM, Balkanci F., Besim A., AJNR A m J Neuroradiol, 1996 Oct, 17 (9): 1651-7, "Interlocking detachable coil occlusion in the endovascular treatment of intracranial aneurysms: preliminary / results.", Department of Radiology, Hacettepe University Hospital, Sihhiye Ankara, Tur key).

Guglielmi et al. (Guglielmi G, Vihuela F, Sepetkai I et al: "Electro-thrombosls of saccular aneurysms via endovascular approach, part I: Electrochemical basis, technique and experimental results", J Neurosurg 1991; 75: 1-7) described the design and application in animal models of an extremely smooth microspiral, Foldable and atraumatic called GDC (Guglielmi Detachable Coi!). In this case, the coil curves were preformed and it was fixed to a steel guide by a welded joint using microengineering techniques, which allowed its progression inside the microcatheter. Once positioned in a satisfactory situation, a small electric current was passed through the mandrel causing electrolysis of the weld point and consequently the release of the spiral.

Moret et al. (Moret J, Picard L, Mawad M et al., "A critica! Study on endovascular treatment of berry aneurysms", Proccedings from the 28th. Annual Meeting of the American Society of Neuroradiology, Los Angeles 1990; p. 35; Moret J Cognard C, Weil A, Castsings L, King A., "Reconstruction technique in the treatment of wide-neck intracranial aneurysms: long-te rm a ngiographic a nd clinic l results", J Neuroradiol 1997; 24: 30-44) They developed a technique for the development of wide-necked aneurysms, which they called "Remodeling", by means of a protective balloon to facilitate the location of the coils in an intra-aneurimatic position and prevent their exit to the bearer vessel.

Currently, for the treatment with coils of wide neck aneurysms, various types of metal meshes or intracranial stents, known devices of coronary revascularization, carotid and peripheral vessel therapy, have been developed (see for example EP 98124245.6, "Aortic graph" "), which have specific qualities in terms of flexibility, and allow them to be placed in front of the aneurysm neck creating a support for the coils, which can be placed through the stent mesh.

EP 00948716.6, "Stent adapted for tangle-free deploymenf, refers to a stent capable of adopting an expanded or retracted configuration based on having in its interior structure a series of extension elements in the form of a fan blade.

US 7651524, "Flexible stenf, describes a stent comprising multiple annular members in the form of scales arranged in axial direction and interconnected to each other. EP0757904," Implantable prosthesis for a human or animal vessel such as stent or aneurysm prosthesis ", describes a prosthesis intended to be implanted in a human or animal conduit to ensure a passage in said conduit. It has a tubular surface with a tube axis, comprising several filaments with undulations, which are wound to define a tubular surface, these undulations forming a series of rings, advantageously in zigzag, staggered in the length of the prosthesis.

In view of the prior art, it would be desirable to have a device specially adapted for the support and placement of coils or spiral occlusive elements, particularly in wide-necked intracranial aneurysms, mainly located in vascular bifurcations, removable by electrolysis, and whose morphology allows retaining said coils inside the aneurysm in order to prevent their exit to the afferent and efferent arteries and also allows the aneurysm embolization procedure to be carried out in a more stable and predictable way, thanks to its ease of handling and repositioning and release capacity.

DESCRIPTION OF THE INVENTION

Therefore, the object of the present invention is to provide a support and placement device for coils or spiral occlusive elements inside a wide-necked intracranial aneurysm, primarily located on vascular bifurcations, removable by electrolysis, and whose shape allows retaining said coils inside the aneurysm, easy to use and with repositioning and releasing capacity. The device of the invention is formed on the basis of an essentially tubular elastic mesh structure made of a memory-shaped material that has a widened configuration at one of its ends or distal end, which is placed on the aneurysm neck. to retain the coils inside, an intermediate part that allows the passage of a microcatheter and that joins the widened distal end to a second or proximal end, the latter being essentially similar to that of a stent, which allows anchoring and stabilize the device in the afferent artery of the aneurysm.

EXPLANATION OF THE FIGURES

The invention will now be described based on the attached figures, in which: Figure 1: Scheme of the design of the invention device according to a preferred embodiment of the same insert in a vascular bifurcation.

Figure 2: Scheme of the positioning of the device and release of the coils inside an aneurysm.

PREFERRED EMBODIMENT OF THE INVENTION.

Although the device of the invention is described in relation to the embolization of a wide neck intracranial aneurysm, the person skilled in the art will understand that its application is not limited to this case, multiple applications thereof being possible, for example in the case of mechanical thrombectomy (thrombus extraction) for the treatment of ischemic stroke, varying if necessary in terms of size and adapting to the anatomy of each particular patient.

Referring to Figure 1, the device of the invention consists of an essentially tubular structure (1) formed from a net or wire mesh (2) of a surgically suitable, elastic and thermal memory material. The tubular structure (1) has a distal end (3) and a proximal end (4), the distal end (3) constituting the part corresponding to the end of the tubular structure (1) that is inserted into the aneurysmal sac (10) and the proximal end (4) constituting the part of the tubular structure opposite the aneurysm, that is, the one that remains in the afferent artery. Both distal (3) and proximal (4) ends of the tubular structure (1) are integrally and structurally connected to each other by a narrowing or neck (6).

As seen in Figure 1, once inserted, the distal end (3) has a funnel or trumpet shape (5) widened with respect to the diameter of the tubular structure (1) and deployed into the aneurysm sac ( 10). Thus, the distal end (3) is inserted, through the neck of the aneurysm (1 1), into the aneurysm sac (10) in order to retain the coils (12) inside allowing the complete closure of the aneurysm and avoiding that the coils invade the afferent and efferent arteries. On the other hand, the narrowing or neck (6) has a suitable diameter to allow the passage of a microcatheter (13) from which the coils (12) are released inside the aneurysm, and, finally, the proximal end (4 ) allows to anchor and stabilize the device in the afferent artery. To facilitate guiding the device through the afferent artery, the proximal end (4) of the device has a detachable guiding element (7) attached to the tubular structure, so that the release of the device into the site is possible adequate and recovery of the guide, for example by a system similar to that usually used in removable stent devices with electrolysis. In one embodiment, the joint between the detachable guiding element (7) and the device is a weld joint releasable by electrolysis.

In a preferred embodiment, the tubular structure (1) formed from a net or wire mesh (2) is made of an elastic alloy with shape memory, such as a nitinol nickel-titanium alloy.

To facilitate its insertion into the afferent artery, the distal end (3) of the device of the invention is capable of folding inside the microcatheter, being deployed once it has been introduced into the aneurysmal sac (10), with the insertion of said microcatheter

If the tubular structure (1) is made of an elastic alloy with a Nitinol-type shape memory and because this material is radiolucent, the device optionally has platinum markers at its distal end (3), neck (6) and at its proximal end (4), allowing the placement of the device in the precise position.

In an exemplary embodiment, the measure of the device of the invention must be selected in the first place, so that it adapts to the anatomy of the arteries and the aneurysm to be embolized, for example based on the measurements taken by Rotational angiography with 3D reconstruction. The aneurysm is catheterized with a microcatheter and the guiding element with standard techniques. With great delicacy, the device is made to ascend through the afferent artery by means of the guiding element, its distal end being deployed within the aneurysm, so that said distal end widens adapting to the aneurysm neck. Thanks to the guiding element and the elasticity of the tubular structure that makes up the device, it can be repositioned until it is at the site determined by the interventional neurradiologist. Once the distal end of the device is positioned on the aneurysm neck, the rest of the device is still released to anchor it in the afferent artery. With a microcatheter, the neck of the device is franked and catheterize the aneurysm sac, then fill with coils using the standard technique. Once the aneurysm is embolized, the device is released.

Claims

1. Support device and placement of coils or spiral occlusive elements for endovascular embolization of aneurysms comprising an essentially tubular structure (1) in net or wire mesh (2) of a surgically suitable, elastic and shape memory material , said tubular structure (1) having a distal end (3) and a proximal end (4), the distal end (3) constituting the part corresponding to the end of the tubular structure (1) that is inserted into the aneurysmal sac (10) ) by means of a microcatheter and the proximal end (4) constituting the part of the tubular structure opposite to the aneurysm, this is the one that remains in the afferent artery, characterized in that both distal (3) and proximal (4) ends of the tubular structure (1) they are joined integrally and in structural continuity to each other by a narrowing or neck (6), the distal end (3) presenting a funnel or trumpet shape (5) widened with respect to the diameter of the tubular structure (1) and deployable into the aneurysm.

2. Device according to claim 1, characterized in that the narrowing or neck (6) has a suitable diameter to allow the passage of a microcatheter from which coils are released inside the aneurysm, and finally the proximal end (4) It allows anchoring and stabilizing the device in the afferent artery.

Device according to claim 1, characterized in that the distal end (3) is capable of folding inside a microcatheter and deploying from it once it has been introduced into the aneurysmal sac (10).

Device according to claim 1, characterized in that the proximal end (4) has a detachable guide element (7) attached to the tubular structure (1) allowing the device to be released.

5. Device according to claim 4, characterized in that the joint between the detachable guiding element (7) and the device is a weld release releasable by electrolysis.

Device according to any one of claims 1 to 4, characterized in that the tubular structure (1) formed from a net or wire mesh (2) is made of an elastic nickel-titanium alloy with shape memory.

Device according to claim 6, characterized in that at its distal end (3), neck (6) and at its proximal end (4) it has platinum markers that facilitate its placement in the precise position.