BALLOON EXPANDING STENT ABLE TO RESTORE EXPANSION Russian patent published in 2010 - IPC A61F2/82 

FIELD: medicine.

SUBSTANCE: invention relates to medical equipment, namely to expanding medical implants for supporting body cavity and, in particular to expanding intraluminal devices, mainly called stents, as well as to systems providing delivery of said stents. Balloon expanding restorable after compression stent contains at least two radial elements, located with formation of tubular element, blocking mechanism for supporting tubular material in expanded state after expansion, and holding mechanism, integrated into radial element for supporting tubular element in compressed state until it is released by radial expansion. Radial elements are movably connected to each other, allowing expansion of tubular element from compressed state to expanded state. Blocking mechanism contains multiple teeth located on first deflected element, which stretches from first end part of radial element to its second end part. Blocking mechanism also contains locking clutch, located on first end part of radial element. Holding mechanism contains at least one hollow located on first holding element, which stretches from first end part of radial element to its second end part. Holding mechanism also contains holding loop, located on second end part of radial element. Radial elements are made from shape memory material to ensure restoration after compression. System of stent delivery contains said balloon expanding stent and catheter with inflatable balloon located along distal end part, where stent is ensured along external surface of inflatable balloon. In second version of implementation balloon expanding restorable after compression stent contains mainly smooth sheet, made from shape memory material, said smooth sheet has configuration for rolling into cylindrical configuration with obtaining tubular element, tubular element has configuration for expansion from compressed state to expanded state, as well as blocking mechanism, and holding mechanism. In third version of implementation balloon expanding restorable after compression stent contains tubular element, which contains a number of pivotally connected links, made from shape memory material, blocking mechanism, formed between first and second end parts of pivotally connected links, holding mechanism and flexible mechanism for connection of multiple links together with formation of stent, which has desirable axial length. Each link contains first and second end elements. Each link contains one or more projections on surface, projections of certain link have configuration for contact with projections of adjacent pivotally connected link in order to limit rotation of said link and adjacent link with respect to each other in direction of compression. Pivotally connected links have configuration allowing leveling of tubular element from compressed to expanded state. In fourth version of implementation expanding stent contains tubular element, which contains a number of elements connected with possibility of sliding, made from biocompatible material, blocking mechanism and holding mechanism. Holding mechanism contains at least one stop, formed along holding element, which stretches from first end part of element to its second end part. Holding mechanism also contains at least one lever located on second end part of element. Lever stretches in such way that lever of first element contacts with stop of second element in order to ensure primary resistance to radial expansion of first and second elements. Lever is deflectable with respect to stop for stop release in case of strong radial expansion of first and second elements. In fifth version of implementation expanding stent contains first and second expanding units, blocking mechanism, flexible connecting part for connection of first and second expanding units together, and holding mechanism. Each expanding unit contains at least one radial element. Each expanding unit forms in fact tubular element and is regulated from compressed to expanded state. Each of expanding units mainly expands independently. In sixth version of stent implementation, in contrast to first, tubular element is made from biocompatible material, and contains at least one radial element and has first end part and second end part. Tubular element has configuration for expansion from compressed to expanded state. Tubular element has central part, located between first and second end parts, at least part of central part of tubular element is made mainly from impermeable wall. In seventh version of implementation balloon expanding restorable after compression stent contains first row of radial elements, expanding along stent longitudinal axis, second row of radial elements, expanding along stent longitudinal axis, blocking mechanism, located on corresponding radial elements of first and second rows, and holding mechanism, integrated into radial elements of first and second rows. Blocking mechanism contains multiple teeth, located on first deflectable element which stretches from first end part of radial element of first row to its second end part. Blocking mechanism also contains locking clutch, located on first end part of second row radial element. Locking clutch of second row radial element functions for gearing of teeth of first row radial element. Holding mechanism contains at least one loop, located at least along first holding element, which stretches from first end part of second row radial element to its second end part. Holding mechanism also contains at least one hook, located on second end part of first row radial element. Radial elements of first row are connected with possibility of sliding with radial elements of second row for obtaining a series of expanding units. Holding mechanism supports at least one expanding unit in compressed state until it is released by radial expansion of inflated balloon. Each of units is expanding to different diametre. In eighth version of stent implementation, holding mechanism contains clearance, formed by at least one deflectable element on second end part of second row radial element. Holding mechanism also contains flexible wing located on second end part of first row radial element. Flexible wing determines contour of passing which is larger than clearance. Wing has such configuration that it can be passed through clearance, when stent is in non-expanded state, and ensure primary resistance to stent radial expansion until it deflects and leaves clearance. First and second rows of radial elements form at least part of tubular element. First and second rows of radial elements are connected with possibility of sliding along multiple points, allowing expansion of tubular element from compressed to expanded state. Holding element supports tubular element in compressed state until it is released by radial expansion of inflated balloon. Method of treating vessels on processed section includes placement of stent delivery system on processed section, and inflation of balloon, which causes stent expansion from compressed to expanded state. In ninth version of implementation balloon expanding restorable after compression stent contains first and second expanding units, blocking mechanism, holding mechanism, and flexible connecting part for connection of first and second expanding units together. Each expanding unit contains a series of connected elements with possibility of sliding, made from shape memory material. Connected elements have configuration allowing unit regulation from compressed into expanded state, each of expanding units mainly expands independently. Blocking mechanism, located on each of first and second expanding units, has such configuration that connected elements slide only in one direction to support expanding units in expanded state. Holding mechanism, located on each of first and second expanding units, has configuration for support of expanding unit in compressed state until it is released by radial expansion of inflated balloon during unrolling on processed section. In tenth version of implementation balloon expanding stent contains at least two mainly flat smooth elements, which have configuration for rolling into cylindrical configuration obtaining tubular element, and expanding envelop, located above tubular element. Each of said smooth elements forms part of tubular element circumference. Elements are connected with possibility to slide allowing expansion of tubular element from compressed state into expanded state without any considerable plastic element deformation. Expanding envelop has configuration for expansion during stent unrolling on processed section.

EFFECT: invention unites desirable qualities of balloon expanding stents and self-expanding stents, namely exact placement, sufficient radial force for supporting cavity in open state under the impact of considerable external force, restoration after compression in such way that stent returns into expanded state in case if stent was compressed or squeezed, etc.

40 cl, 25 dwg