Description:FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(Section 10 and Rule 13)

1. TITLE OF THE INVENTION:
STENT GRAFT DELIVERY SYSTEM
2. APPLICANT:
Meril Life Sciences Pvt. Ltd., an Indian company of the address Survey No. 135/139 Bilakhia House, Muktanand Marg, Chala, Vapi-Gujarat 396191, India.

The following specification particularly describes the invention and the manner in which it is to be performed:

 
FIELD OF INVENTION
[001] The present invention relates to a medical device. More specifically, the present invention relates to a stent graft delivery system.
BACKGROUND OF INVENTION
[002] A thoracic aortic aneurysm (TAA) is a bulge or dilation in the wall of the thoracic aorta, which is the part of the aorta that runs through the chest. This condition can occur due to a weakening in the aortic wall, which causes it to stretch and form an aneurysm. If left untreated, a TAA can grow larger and may eventually rupture, which is a life-threatening emergency.
[003] The treatment may involve an open surgery to directly access the aorta and remove the damaged section of the aorta, which is then replaced with a synthetic graft. Alternate treatment method involves a minimally invasive option in which a delivery system is used to deliver and deploy a stent graft to the site of aneurysm to reinforce the weakened area of the aorta.
[004] The delivery systems include a stent deployment mechanism for deploying the stent graft at a delivery site (i.e., thoracic aorta). The deployment mechanism is controlled using a control assembly. The conventionally used control assembly includes a control element to control the deployment or release of the stent graft. However, in conventional delivery systems, there is increased chance of unintended manipulation of the control element, causing a pre-mature release of the stent graft or release of the stent graft at an unintended site. This reduces the efficacy of the delivery procedure and may also lead to adverse consequences for the patient.
[005] Therefore, there is a need of a delivery system that can overcome the problems associated with the conventionally available delivery systems.

SUMMARY OF INVENTION
[006] The present disclosure discloses a delivery system for delivering a stent graft. The delivery system includes a catheter and a control assembly coupled to the catheter. The catheter includes a first tube and a holding element coupled to a distal end of the first tube. The holding element is configured to engage with a stent graft mounted on the first tube. The control assembly includes a second control element and a locking member. In an embodiment, the second control element is coupled to the first tube and is configured to move the first tube and the holding element longitudinally to release the stent graft. The locking member is configured to restrict movement of the second control element.
[007] The foregoing features and other features as well as the advantages of the invention will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures.
BRIEF DESCRIPTION OF DRAWINGS
[008] The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the apportioned drawings. For the purpose of illustrating the present disclosure, exemplary constructions of the disclosure are shown in the drawings. However, the disclosure is not limited to specific methods and instrumentalities disclosed herein. Moreover, those in the art will understand that the drawings are not to scale.
[009] Fig. 1 depicts a side view of a delivery system 100 for delivering a stent graft, in accordance with an embodiment of the present invention.
[0010] Fig. 2 depicts an exploded view of the delivery system 100, in accordance with an embodiment of the present disclosure.
[0011] Fig. 3 depicts a longitudinal cross-sectional view of a catheter 300, in accordance with an embodiment of the present disclosure.
[0012] Fig. 4 depicts a tip member 400 coupled to an inner tube 320 of the catheter 300, in accordance with an embodiment of the present disclosure.
[0013] Fig. 5 depicts a perspective view of the tip member 400, in accordance with an embodiment of the present disclosure.
[0014] Fig. 6 depicts a holding element 350 coupled to a first tube 330 of the catheter 300 and the tip member 400, in accordance with an embodiment of the present disclosure.
[0015] Figs. 7a and 7b depict various perspective views of the holding element 350, in accordance with an embodiment of the present disclosure.
[0016] Fig. 8 depicts a stopper 341 coupled to a second tube 340 of the catheter 300, in accordance with an embodiment of the present disclosure.
[0017] Fig. 8a depicts a perspective view of a section of the second tube 340, in accordance with an embodiment of the present disclosure.
[0018] Fig. 8b depicts an enlarged view of the second tube 340, in accordance with an embodiment of the present disclosure.
[0019] Fig. 8c depicts a transversal cross-sectional view of the second tube 340, in accordance with an embodiment of the present disclosure.
[0020] Fig. 9 depicts a perspective view of the stopper 341, in accordance with an embodiment of the present disclosure.
[0021] Fig. 10 depicts a perspective view of a control assembly 200, in accordance with an embodiment of the present disclosure.
[0022] Fig. 11 depicts a side view of a guide rail 210 of the control assembly 200, in accordance with an embodiment of the present disclosure.
[0023] Fig. 12 depicts a perspective view of a first section 210c of the guide rail 210, in accordance with an embodiment of the present disclosure.
[0024] Fig. 13 depicts a perspective view of a first control element 220 of the control assembly 200, in accordance with an embodiment of the present disclosure.
[0025] Fig. 14 depicts a perspective view of a housing 270 of the first control element 220, in accordance with an embedment of the present disclosure.
[0026] Fig. 15 depicts a section view of the housing 270, in accordance with an embodiment of the present disclosure.
[0027] Fig. 16 depicts a perspective view of a switching element 240 of the control assembly 200, in accordance with an embodiment of the present disclosure.
[0028] Fig. 17 depicts a cross-section view of a frame 245 of the switching element 240, in accordance with an embodiment of the present disclosure.
[0029] Fig. 18 depicts a perspective view of an inner element 243 of the switching element 240, in accordance with an embodiment of the present disclosure.
[0030] Fig. 19 depicts a section view of a distal portion of the control assembly 200, in accordance with an embodiment of the present disclosure.
[0031] Fig. 20 depicts a perspective view of a first hub 260, in accordance with an embodiment of the present disclosure.
[0032] Fig. 21 depicts a perspective view of a proximal portion of the delivery system 100 along with a locking member 230, in accordance with an embodiment of the present disclosure.
[0033] Fig. 22a depicts a perspective view of a second control element 280 of the control assembly 200, in accordance with an embodiment of the present disclosure.
[0034] Fig. 22b depicts a section view of the second control element 280, in accordance with an embodiment of the present disclosure.
[0035] Fig. 23 depicts a section view of the proximal portion of the delivery system 100, in accordance with an embodiment of the present disclosure.
[0036] Fig. 24 depicts a perspective view of a second hub 290, in accordance with an embodiment of the present disclosure.
[0037] Fig. 25 depicts a perspective view of the locking member 230, in accordance with an embodiment of the present disclosure.
[0038] Fig. 26 depicts a perspective view of a third hub 295, in accordance with an embodiment of the present disclosure.
[0039] Fig. 27 depicts a flow chart of an exemplary method 2700 for deploying a stent graft 10 using the delivery system 100, in accordance with an embodiment of the present disclosure.
[0040] Fig. 28 depicts a configuration of the control assembly 200, specifically, the first control element 220 at an undeployed state, in accordance with an embodiment of the present disclosure.
[0041] Fig. 28a depicts the stent graft 10 in a partially deployed state, in accordance with an embodiment of the present disclosure.
[0042] Fig. 28b depicts a configuration of the first control element 220 at the partially deployed state, in accordance with an embodiment of the present disclosure.
[0043] Fig. 28c depicts the control assembly with the locking member 230 disengaged from the guide rail 210, in accordance with an embodiment of the present disclosure.
[0044] Fig. 28d depicts the stent graft 10 disengaged from the delivery system 100, in accordance with an embodiment of the present disclosure.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[0045] Prior to describing the invention in detail, definitions of certain words or phrases used throughout this patent document will be defined: the terms "include" and "comprise", as well as derivatives thereof, mean inclusion without limitation; the term "or" is inclusive, meaning and/or; the phrases "coupled with" and "associated therewith", as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have a property of, or the like; Definitions of certain words and phrases are provided throughout this patent document, and those of ordinary skill in the art will understand that such definitions apply in many, if not most, instances to prior as well as future uses of such defined words and phrases.
[0046] Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment, but mean “one or more but not all embodiments” unless expressly specified otherwise. The terms “including,” “comprising,” “having,” and variations thereof mean “including but not limited to” unless expressly specified otherwise. An enumerated listing of items does not imply that any or all of the items are mutually exclusive and/or mutually inclusive, unless expressly specified otherwise. The terms “a,” “an,” and “the” also refer to “one or more” unless expressly specified otherwise.
[0047] Although the operations of exemplary embodiments of the disclosed method may be described in a particular, sequential order for convenient presentation, it should be understood that the disclosed embodiments can encompass an order of operations other than the particular, sequential order disclosed. For example, operations described sequentially may in some cases be rearranged or performed concurrently. Further, descriptions and disclosures provided in association with one particular embodiment are not limited to that embodiment, and may be applied to any embodiment disclosed herein. Moreover, for the sake of simplicity, the attached figures may not show the various ways in which the disclosed system, method, and apparatus can be used in combination with other systems, methods, and apparatuses.
[0048] Furthermore, the described features, advantages, and characteristics of the embodiments may be combined in any suitable manner. One skilled in the relevant art will recognize that the embodiments may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments. These features and advantages of the embodiments will become more fully apparent from the following description and apportioned claims, or may be learned by the practice of embodiments as set forth hereinafter.
[0049] In accordance with the present disclosure a delivery system is disclosed to the delivery system is used for delivering a stent graft in a procedure such as, without limitation, an endovascular aneurism repair (EVAR). The delivery system includes a control assembly and a catheter. The catheter includes a plurality of tubes. In an embodiment, the catheter includes an outer sheath, an inner tube, a first tube and a second tube. The tubes are configured to slide longitudinally with respect to each other during the deployment of the stent graft. For example, the outer sheath is configured to slide in a proximal direction to expose the stent graft out of the catheter and the first tube is configured to move in a proximal direction to release the stent draft from the delivery system. The motion of the outer sheath and the first tube is controlled using the control assembly. In an embodiment, the control assembly includes two or more control elements that are coupled to a corresponding tube. The control elements are operated to impart motion to a corresponding tube of the catheter. The control elements of the present delivery system can easily be operated to reduce the complexity of the deployment procedure. In an embodiment, the delivery system includes a first control element coupled to the outer sheath and a second control element coupled to the first tube. The first control element is movable longitudinally via a threaded mechanism and/or a sliding mechanism to provide a corresponding longitudinal motion to the outer sheath. In an embodiment, the first control element can easily be toggled between the threaded mechanism and the sliding mechanism to precisely and/or quickly expose the stent graft out of the outer sheath. In an embodiment, the second control element may be operated via a sliding mechanism. Further, to avoid any unintended operation or manipulation of the second control element which may cause pre-mature release of the stent graft, the motion of the second control element may be restricted using a locking member. The easy operation of the first control element and the second control element makes it easy to deploy the stent graft using the delivery system of the present disclosure, reducing the time required for the procedure and decreases the operator fatigue. Additionally, the locking member prevents unintended operation of the second control element thereby avoiding pre-mature release of the stent graft. This increases the accuracy and precision of the stent delivery using the proposed delivery system.
[0050] Now referring to figures, Fig. 1 depicts a side view of a delivery system 100 and Fig. 2 depicts an exploded view of the delivery system 100, according to an embodiment. The delivery system 100 is used to deliver a stent graft to a target site (e.g., thoracic aorta) and thereafter, deploy the stent graft at the target site. The delivery system 100 has a proximal end 100a and a distal end 100b. The delivery system 100 includes a control assembly 200 and a catheter 300. The control assembly 200 is positioned towards the proximal end 100a. The catheter 300 is coupled to the control assembly 200. The control assembly 200 is used to control various sub-components of the catheter 300 to deploy a stent graft. The delivery system 100 includes a tip member 400 disposed at the distal end 100b of the delivery system 100. The tip member 400 is coupled to the catheter 300 (explained in detail later).
[0051] The catheter 300 has a proximal end (not shown) and a distal end 300b. The proximal end of the catheter 300 is disposed within the control assembly 200. The distal end 300b of the catheter 300 is coupled to the tip member 400. The catheter 300 has an elongated, tubular structure, defining a plurality of lumens. The catheter 300 includes a plurality of concentric tubes forming multiple lumens. In an embodiment, the catheter 300 includes an outer sheath 310, an inner tube 320, a first tube 330 and a second tube 340 disposed coaxially, clearly show in Fig. 3.
[0052] The outer sheath 310 corresponds to an outermost tube of the catheter 300. The outer sheath 310 encloses the inner tube 320, the first tube 330 and the second tube 340. The outer sheath 310 has a proximal end 310a and a distal end (not shown). In an embodiment, the outer sheath 310 has an elongated, tubular structure, defining a lumen. The outer sheath 310 is configured to accommodate the stent graft towards the distal end. In an embodiment, the stent graft is disposed within a distal portion of the outer sheath 310. The stent graft remains in a crimped state within the outer sheath 310. The outer sheath 310 is configured to slide longitudinally over an outer surface of the stent graft. The outer sheath 310 slides from the distal end 100b towards the proximal end 100a of the delivery system 100 to expose the stent graft at the time of deployment. Once the constraint of the outer sheath 310 is removed, an exposed portion of the stent graft radially expands due to the self-expanding property of the stent graft.
[0053] In an embodiment, the inner diameter of the outer sheath 310 is greater than or equal to the outer diameter of the stent graft in the crimped state. The inner diameter of the outer sheath 310 may range from 5.3 mm to 7.9 mm. In an embodiment, the inner diameter of the outer sheath 310 is 7.2mm. The outer diameter of the outer sheath may be chosen based upon the clinical needs or the anatomy of a patient. The outer diameter of the outer sheath 310 may range between 6.5 mm and 8.5 mm. In an embodiment, the outer diameter of the outer sheath 310 is 8 mm. The outer sheath 310 may be made of a material including, but not limited to, polyurethane (PU), polyether ether ketone (PEEK), polytetrafluoroethylene (PTFE), polyether block amide (PEBAX), etc. In an embodiment, the outer sheath 310 is made of PTFE.
[0054] The inner tube 320 is disposed within the outer sheath 310. The inner tube 320 corresponds to the innermost tube of the catheter 300. The inner tube 320 has a proximal end (not shown) and a distal end 320b (shown in Fig. 4). The inner tube 320 extends from the proximal end 100a to the distal end 100b of the delivery system 100. At least a portion of the inner tube 320 is disposed within the control assembly 200. The inner tube 320 has an elongated tubular structure, defining a lumen. The lumen of the inner tube 320 is configured to provide a passage to a guidewire (not shown) to be navigated to the site of delivery, during the deployment procedure.
[0055] The inner tube 320 may be made of a material including, but not limited to, PU, PTFE, PEEK, silicone, nylon, polypropylene (PP), polycarbonate, etc. In an embodiment, the inner tube is made of PEEK. In an embodiment, the inner diameter of the inner tube 320 is greater than or equal to an outer diameter of the guidewire. The inner diameter of the inner tube 320 may range between 0.65 mm and 1.10 mm. In an embodiment, the inner diameter of the inner tube 320 is 0.95 mm. In an embodiment, the distal end 320b of the inner tube 320 is coupled to the tip member 400 provided at the distal end 100b (shown in Fig. 4).
[0056] Referring to Fig. 5, the tip member 400 has a proximal end 400a and a distal end 400b. The tip member 400 may have a cavity 411 extending from the proximal end 400a to the distal end 400b. The cavity 411 may be cylindrical. The cavity 411 of the tip member 400 is configured to provide a passage to the guidewire. In an embodiment, the tip member 400 includes a proximal portion 410 and a distal portion 430. The proximal portion 410 is disposed towards the proximal end 400a of the tip member 400. In an embodiment, the proximal portion 410 of the tip member 400 has a cylindrical shape, though it may have any other suitable shape. The distal portion 430 of the tip member 400 has a conical shape configured to facilitate motion of the catheter 300 within the vasculature. The conical shape of the distal portion 430 helps dilating the vasculature gradually to allow the catheter 300 to pass through without damaging the inner walls of the blood vessels, thereby reducing trauma to the vessels. Further, the tip member 400 is made of a soft biocompatible material to minimize trauma to the vasculature during the navigation of the catheter 300. The soft biocompatible material may include, without limitation, silicone, PU, thermoplastic elastomers, latex, polypropylene, etc.
[0057] The tip member 400 is coupled to the distal end 320b of the inner tube 320. The tip member 400 may be coupled to the distal end 320b of the inner tube 320 using welding, adhesive, boding, slot fit coupling, threading, swaging, etc. In an embodiment, the tip member 400 and the inner tube 320 are coupled using slot fit coupling.
[0058] The first tube 330 is disposed between the inner tube 320 and the outer tube 310. In other words, the first tube 330 is disposed within the outer sheath 310 and the inner tube 320 is disposed within the first tube 330. The first tube 330 has a proximal end 330a and a distal end 330b. The proximal end 330a of the first tube 330 is disposed within the control assembly 200. The first tube 330 has an elongated, tubular structure, defining a lumen (not shown) configure to receive the inner tube 320. The first tube 330 extends from the proximal end 100a of the delivery system 100 to the distal end 100b of the delivery system 100. The first tube 330 is disposed over the inner tube 320. The first tube 330 is configured to slide longitudinally over the inner tube 320 to deploy the stent graft at the target site (explained later).
[0059] In an embodiment, the inner diameter of the first tube 330 is greater than or equal to the outer diameter of the inner tube 320. The inner diameter of the first tube 330 may range between 1.35 mm and 1.90 mm. In an embodiment, the inner diameter of the first tube 330 is 1.61 mm. The outer diameter of the first tube 330 may range between 1.95 mm and 2.40 mm. In an embodiment, the outer dimeter of the first tube 330 is 2.10 mm. The first tube 330 may be made of a material including, but not limited to, PEEK, PU, PTFE, PEBAX, silicone, latex, polypropylene, etc. In an embodiment, the first tube 330 is made of PEEK. The distal end 330b of the first tube 330 is coupled to a holding element 350 (shown in Fig. 6).
[0060] Referring to Figs. 7a and 7b, the holding element 350 is disposed towards the distal end 300b of the catheter 300. The holding element 350 is configured to engage with or hold the stent graft within the catheter 300 during the navigation of the catheter 300 to the target site and release the stent graft from the catheter 300 at the time of deployment. The holding element 350 has a first section 351 and a second section 353.
[0061] The first section 351 is disposed towards a distal end of the holding element 350. The first section 351 includes a plurality of extensions 355. In an embodiment, the first section 351 includes five extensions 355. It should be understood that the number of extensions 355 may be less than or greater than five based upon requirements. In an embodiment, the extensions 355 are arranged circumferentially (uniformly or non-uniformly) on the periphery of the first section 351 of the holding member 350. In an embodiment, the extensions 355 are uniformly distributed. The extensions 355 extend away from the second section 353 towards the distal end 300b of the catheter 300. In an embodiment, the extensions 355 rest on an outer surface of the proximal portion 410 of the tip member 400. A distal end of each extension 355 mates a proximal face 431 of the distal portion 430 of the tip member 400. In an embodiment, each extension 355 is configured to engage with the stent graft to fix the position of the stent graft on the catheter 300 during navigation of the catheter 300 through the vasculature of the patient. For example, a filament cell or loop (not shown) may be provided on the stent graft to engage with a corresponding extension 355 to fix the position of the stent graft on the catheter during navigation. That is, each extension 355 is configured to engage with a corresponding filament cell or loop of the stent graft. In an embodiment, each extension 355 passes through a corresponding filament cell or loop of the stent graft. The filaments of the said cells or loops of the stent graft are fixed or disposed between the outer surface of the proximal portion 410 of the tip member 400 and an inner surface of a corresponding extension 355. In other words, the filaments of the cells or loops form a loop around a corresponding extension 355 and are fixed between the outer surface of the proximal portion 410 of the tip member 400. According to an embodiment, in response to the movement of the holding element 350 in the proximal direction, the extension 355 is configured to disengage from the corresponding filament cell or loop of the stent graft. When the holding element 350 moves in the proximal direction, the extensions 355 come out of the corresponding filament cells or loops, releasing the stent graft from the delivery system 100.
[0062] The second section 353 of the holding element 350 is disposed towards a proximal end of the holding element 350. The second section 353 is used to couple the holding element 350 with the first tube 330. In an embodiment, the second section 353 of the holding member 350 has a generally cylindrical shape. The second section 353 includes an aperture 357. The aperture 357 receives a portion of the first tube 330 to couple the first tube 330 and the holding element 350. The first tube 330 and the holding element 350 may be coupled using, welding, adhesive, bonding, threading, swaging, etc. In an embodiment, the first tube 330 and the holding member 350 are coupled using a thread mechanism. In an embodiment, the aperture 357 of the second section 353 of the holding member 350 is provided with internal threads 357a configured to mate with corresponding threads (not shown) provided on an outer surface of the first tube 330 at the distal end 330b of the first tube 330. The holding member 350 is configured to move longitudinally in response to the longitudinal motion of the first tube 330. The holding element 350, when moved in the proximal direction, releases the loops or cells of the stent graft to release the stent graft from the catheter 300. When the holding element 350 moves away from the distal portion 430 of the tip member 400, the loops or cells are released as the loops or cells expand, thereby releasing the stent graft from the catheter 300. The holding member 350 may be made of a material including, without limitation, nickel-titanium, tantalum, stainless steel, copper, gold, etc. In an embodiment, the holding member 350 is made of stainless steel.
[0063] The second tube 340 is disposed within the outer sheath 310. In an embodiment, the second tube 340 is disposed between the first tube 330 and the outer sheath 310. The second tube 340 is configured to provide structural stability to the catheter 300. The second tube 340 has a proximal end (not shown) and a distal end 340b. The distal end 340b of the second tube 340 is located at a pre-defined distance proximal to the distal end of the first tube 330. In an embodiment, the stent graft is mounted over the first tube 330 between the distal end 330b of the first tube 330 and the distal end 340b of the second tube 340. The pre-defined distance between the distal end 340b of the second tube 340 and the distal end 330b of the first tube 330 is chosen depending upon the length of the stent graft. For example, the pre-defined distance is greater than or equal to the length of the stent graft.
[0064] Referring to Fig. 8, 8a and 8b, the second tube 340 has an elongated, tubular structure, defining a lumen configured to receive the first tube 330 or in other words the first tube 330 is disposed within the second tube 340. The inner diameter of the second tube 340 may be greater than or equal to the outer diameter of the first tube 330 to allow the first tube 330 to slide longitudinally within the second tube 340. The inner diameter of the second tube 340 may range between 2.00 mm and 2.5 mm. In an embodiment, the inner diameter of the second tube 340 is 2.20 mm. The outer diameter of the second tube 340 may range between 3.0 mm and 5.00 mm. In an embodiment, the outer diameter of the second tube 340 is 4.5 mm.
[0065] In an embodiment, the second tube 340 may include at least one braided layer 343 (shown in Fig. 8b and 8c). The braided layer 343 includes a plurality of filaments braided to form a braided structure. The braided layer 343 has an inner surface and an outer surface. The second tube 340 may include an inner layer 342 and an outer layer 345 coupled to the braided layer 343 such that the inner layer 342 is coupled to the inner surface of the braided layer 343 and the outer layer 345 is coupled to the outer surface of the braided layer 343. In an embodiment, the inner layer 342, the braided layer 343 and the outer layer 345 of the second tube 340 are fused together using, for example, a heat shrinking process. The braided layer 343 of the second tube 340 provides flexibility and resilience to the catheter 300, thereby allowing the catheter 300 to easily navigate through the curves of the vasculature without deforming and/or kinking. The filaments of the second tube 340 may be made of material including, but not limited to stainless steel, nitinol, copper, platinum, platinum-tungsten, polyester, etc. In an embodiment, the filaments are made of stainless steel. The filaments of the second tube 340 may be braided in a predefined braiding pattern, such as, without limitation, spiral braiding, double braiding, over-under braiding, reverse braiding, etc. In an embodiment, the filaments of the second tube 340 are braided in spiral braiding pattern. In an embodiment, the filaments are braided over each other such that two adjacent filaments form an angle A (shown in Fig 8b) at the point of intersection. The angle A may range between 20 degrees and 60 degrees. In an embodiment, the angle A is 35 degrees. The number of filaments braided together to form the braided structure of the second tube may range between 12 and 20. In an embodiment, the number of the filaments in the braided structure of the second tube 340 is 16. The second tube 340 includes a stopper 341 provided at the distal end 340b of the second tube 340 (shown in Fig. 8).
[0066] Fig. 9 depicts the stopper 341 of the second tube 340. The stopper 341 is configured to restrict a proximal motion of the stent graft during navigation to the target site and/or at the time of deployment. A proximal portion of the stent graft is coupled to a distal end of the stopper 341.In an embodiment, the stopper 341 has a cylindrical shape, though it may have any other suitable shape. In an embodiment, the stopper 341 includes a lumen 341a configured to provide a passage to the first tube 330. The lumen 341a receives and is coupled to the distal end 340b of the second tube 340 to couple the stopper 341 and the second tube 340. The stopper 341 may be coupled to the distal end 340b of the second tube 340 using a coupling technique, such as without limitation, chemical bonding, fusion, mechanical joint, etc. In an embodiment, the stopper 341 is coupled to the distal end 340b of the second tube 340 using chemical bonding. In an embodiment, the lumen 341a receives the proximal portion of the stent graft to couple the stent graft with the stopper 341. In other words, the proximal portion of the stent graft is disposed within the lumen 341a, thereby coupling the stent graft with the stopper 341. The outer diameter of the stopper 341 is greater than the outer diameter of the second tube 340. This enables the stent graft to be easily loaded and coupled with the stopper 341 without a risk of disengagement. The outer diameter of the stopper 341 may range between 4 mm and 8 mm. In an embodiment, the outer diameter of the stopper 341 is 7 mm. In an embodiment, a proximal end of the stopper 341 has a tapered structure such that the outer diameter of the stopper 341 decreases towards the proximal end. The tapered structure is provided to facilitate the coupling between the second tube 340 and the stopper 341. The stopper 341 may be made of a material, such as, without limitation, thermoplastic polyurethane (TPU), nylon, silicone, medical grade rubber, etc. In an embodiment, the stopper 341 is made of TPU.
[0067] Additionally, or optionally, the second tube 340 is provided with a sealing member 342 (shown in Fig. 2). The sealing member 342 is configured restrict leakage of any fluid such as blood, saline fluid out of the second tube 340 during the procedure. The sealing member 342 is coupled to the proximal end of the second tube 340. The sealing member 342 has a hollow cylindrical shape, having a cavity to receive the proximal end of the second tube 340 and coupled with it using, for example, chemical bonding or UV glue etc.
[0068] Fig. 10 depicts a perspective view of the control assembly 200, in accordance with an embodiment of the present disclosure. The control assembly 200 is disposed towards the proximal end 100a of the delivery system 100. The control assembly 200 has a proximal end 200a and a distal end 200b. The control assembly 200 is configured to control the longitudinal motion of the outer sheath 310 and the first tube 330 during the deployment of the stent graft. In an embodiment, the control assembly 200 includes a first control element 220 and a second control element 280. The first control element 220 and the second control element 280 are configured to control the motion of the outer sheath 310 and the first tube 330, respectively, which is explained in detail later. The control assembly 200 further includes a first hub 260 (shown in Fig. 17), a second hub 290 (shown in Fig. 21), and a third hub 295 (shown in Fig. 26).
[0069] Referring to Fig. 11, the control assembly 200 includes a guide rail 210. The guide rail 210 has a cylindrical shape. The guide rail 210 has hollow structure, defining a cavity 210econfigured to accommodate a proximal portion of the catheter 300, the first hub 260 and the second hub 290. In an embodiment, the guide rail 210 has a proximal portion 210a and a distal portion 210b. In an embodiment, the distal portion 210b of the guide rail 210 includes a threaded portion 218 having external threads 218a, extending for at least a partial length of the distal portion 210b. In an example implementation, threaded portion 218 extends for a partial length of the distal portion 210b. Additionally, or optionally, the distal portion 210b of the guide rail 210 includes a gripping portion 213 towards a distal end of the guide rail 210. The gripping portion 213 may have an ergonomic shape to allow an operator to grip the guide rail 210 easily. In an embodiment, the threaded portion 218 is provided with a pair of first longitudinal slots 215. The pair of first longitudinal slots 215 are positioned diametrically opposite to each other on a corresponding lateral side of the guide rail 210. The first longitudinal slots 215 extend for a partial length of the threaded portion 218 of the guide rail 210. The first longitudinal slots 215 are configured to provide a passage to a portion of the first hub 260 to extend out of the distal portion 210b of the guide rail 210 (described later) and help in coupling the first hub 260 with the first control element 220. The first longitudinal slots 215 also help in longitudinal movement of the first hub 260 within the cavity 210e of the guide rail 210. In an embodiment, the guide rail 210 includes a pair of second longitudinal slots 217. The second longitudinal slots 217 are provided on the proximal portion 210a. The second longitudinal slots 217 extend for a partial length of the proximal portion 210a of the guide rail 210. Each second longitudinal slot 217 of the pair of second longitudinal slot 217 is positioned diametrically opposite to each other. In an embodiment, the first longitudinal slots 215 and the second longitudinal slots 217 align with each other. Further, the guide rail 210 includes a pair of holes 212 to allow a corresponding potion of the third hub 295 to extend out of the guide rail 210 (described later). The holes 212 are provided on the distal portion 210b of the guide rail 210 towards the proximal end 200a of the control assembly 200. The pair of holes 212 is positioned diametrically opposite to each other on the guide rail 210. Each hole 212 aligns with a respective first longitudinal slot 215 and the second longitudinal slot 217. The guide rail 210 may be made of two sections – a first section 210c and a second section 210d (shown in Fig. 2). The first section 210c and the second section 210d are coupled together to form the guide rail 210. In an embodiment, the first section 210c and the second section 210d of the guide rail 210 are coupled using snap fit locking mechanism. The guide rail 210 may be made of a material including, but not limited to, acrylonitrile butadiene styrene (ABS), polycarbonate, etc. In an embodiment, the guide rail 210 is made of polycarbonate.
[0070] In an embodiment, the guide rail 210 has a stepped diameter configuration. For example, the proximal portion 210a of the guide rail has a smaller diameter than a diameter of the distal portion 210b of the guide rail 210. The stepped diameter of the guide rail 210 facilitates easy grip of the operator on the guide rail 210.
[0071] Additionally, or optionally, the guide rail 210 may include a pair of rails 219 (shown in Fig. 12) on an inner surface of the cavity 210e of the guide rail 210 at a top and a bottom end of the guide rail 210. For example, each of the first section 210c and second section 210d of the guide rail 210 may be provided with one pair of rails 219 shown in Fig. 12. The rails 219 extends for the length of the threaded portion 218. The pair of rails 219 are parallel to each other. The rails 219 facilitate a smooth movement of the first hub 260 (explained later).
[0072] Fig. 13 depicts the first control element 220 of the control assembly 200. The first control element 220 is coupled to the outer sheath 310 and the guide rail 210. The first control element 220 is configured to move the outer sheath 310 longitudinally. In an embodiment, in response to the longitudinal movement of the first control element 220 in the proximal direction, the outer sheath 310 is configured to move longitudinally in the proximal direction to expose the stent graft. Similarly, in response to the longitudinal movement of the first control element 220 in the distal direction, the outer sheath 310 is configured to move longitudinally in the distal direction. The first control element 220 includes a housing 270 and a switching element 240.
[0073] Referring to Fig. 14, the housing 270 of the first control element 220 may have an ergonomic design to facilitate an easier grip to the operator on the housing 270. The housing 270 is coupled to the guide rail 210 and the outer sheath 310. In an embodiment, the housing 270 has a hollow, cylindrical shape defining a first lumen 278 configure to receive the threaded portion 218 of the guide rail 210. The housing 270 is disposed on the guide rail 210. The housing 270 is configured to move longitudinally over the outer surface of the guide rail 210. The housing 270 may be made of a first section 270a and a second section 270b (shown in Fig. 2) coupled together to form the housing 270. The first section 270a and the second section 270b may be positioned towards a bottom end and a top end of the control assembly 200, respectively. The first section 270a and the second section 270b may be coupled using a coupling technique, such as, without limitation, adhesive, snap-fit mechanism, a stud-groove coupling mechanism adhesive bonding, heat staking, ultrasonic welding, etc. In an embodiment, the first section 270a and the second section 270b of the housing 270 are coupled using snap fit locking mechanism. The housing 270 may be made of a material including, but not limited to ABS, polycarbonate, etc. In an embodiment, the housing 270 is made of polycarbonate. The housing 270 includes a pair of slots 271, a first cavity 273 and a second cavity 275 (shown in Fig. 15). The slots 271 are positioned towards a distal end of the housing 270. The slots 271 are positioned diametrically opposite to each other. Each of the first section 270a and second section 270b are provided with one of the slots 271. In an embodiment, the slots 271 have a rectangular shape though the slots 271 may have any other shape, such as, without limitation, circular, rectangular, etc. The slots 271 extend into the first cavity 273. The first cavity 273 is configured to receive the switching element 240. The second cavity 275 is configured to receive a portion of the first hub 260 (explained later). The first control element 220 is operable in a first mode and a second mode. In the first mode, the first control element 220 is coupled to the threaded portion 218 of the guide rail 210 and is rotatable to move the first control element 220 longitudinally. In the second mode, the first control element 220 is disengaged from the threaded portion 218 of the guide rail 210 and is slidable over the threaded portion 218. The first control element 220 can be n toggled between these two operating modes using the switching element 240. In other words, the switching element 240 is configured to toggle the first control element 220 between the first and second mode.
[0074] Referring to Fig. 14. The switching element 240 is disposed within the first cavity 273 of the housing 270. The switching element 240 has a first end 240a and second end 240b. At least a portion of the switching element 240 at the first end 240a extends out of a corresponding slot 271 of the pair of slots 271 of the housing 270 (as shown in Fig. 10). The switching element 240 includes a frame 245 and an inner element 243. The frame 245 includes a first portion 245a, a second portion 245b and a third portion 245c. The first portion 245a is disposed towards the first end 240a of the switching element 240. In an embodiment, the first portion 245a extends out of the first cavity 273 of the housing 270 and is capable of receiving an actuation input. The third portion 245c is disposed towards the second end 240b of the switching element 240. The second portion 245b is disposed between the first portion 245a and the third portion 245c. The second portion 245b resides within the first cavity 273 of the housing 270. In an embodiment, the first portion 245a and the third portion 245c have a rectangular shape though the first portion 245a and the third portion 245c may have any other suitable shape. The second portion 245b has a generally hollow cylindrical shape and is configured to receive the threaded portion 218 of the guide rail 210. The frame 245 may be made of a material including, but not limited to ABS, polycarbonate, etc. In an embodiment, the frame 245 is made of ABS. The inner element 243 is disposed within the frame 245. The frame 245 and the inner element 243 are slidably coupled. For example, the frame 245 is configured to slide over lateral edges of the inner element 243. The first portion 245a of the frame 245 may include a cavity corresponding to the shape of the inner element 243. The inner element 243 includes a base 234b provided towards the second end 240b of the switching element 240 and a pair of pegs 243a extending away from the base 234b towards the first end 240a of the switching element 240. The base 243b includes a curved face 243b1 provided towards the second end 240b. The curved face 243b1 of the base 243b seats against the threaded portion 218 of the guide rail 210. The inner element 234 facilitate the engagement of the first control element 220 and the guide rail 210. The frame 245 includes a pair of apertures 241. Each peg 243a is disposed within a corresponding aperture 241 of the frame 245 (shown in Fig 16). In an embodiment, the switching element 240 includes a pair of resilient members (not shown). Each resilient member is disposed in gap between a top end of a respective peg 234a and a top end of the respective aperture 241. The resilient members are configured to apply a biased (or biasing) force to move the frame 245 towards the first end 240a to a default position or push the inner element 234 towards the threads of the guide rail 210, such that the curved face 234b1 remains in contact with the threaded portion 218 of the guide rail 210 to support the engagement and/or disengagement of the first control element 220 with the guide rail 210. The switching element 240 is configured to engage and/or dis-engage the first control element 220 with the external threads 218a of the guide rail 210. The frame 245 of the switching element 240 is provided with internal threads 242 towards the second end 240b. In an embodiment, the internal threads 242 are provided on an edge 245c1 of the third portion 245c of the frame 245 of the switching element 240. The internal threads 242 are configured to selectively engage with the external threads 218a of the guide rail 210 to engage and\or disengage the first control element 220 with the guide rail 210. In an unactuated state of the switching element 240, the internal threads 242 of the switching element 240 are engaged with the external threads 218a of the guide rail 210 thereby engaging the first control element 220 with the guide rail 210, configuring the first control element 220 in the first mode. Thus, in the first mode, the internal threads 242 of the switching element 240 are engaged with the external threads 218a of the guide rail 210, enabling the first control element 220 to rotate. Further, in the first mode, the first control element 220 is threadedly coupled to the guide rail 210 and in response to the rotation of the first control element 220, the first control element 220 is configured to slide longitudinally over the guide rail 210 due to the threaded coupling therebetween. For example, when the first control element 220 is rotated in a first direction (e.g., an anti-clockwise direction), the first control element 220 moves towards the proximal end 200a of the control assembly 200, i.e., in a proximal direction and when the first control element 220 is rotated in a second direction (i.e., a clockwise direction), the first control element 220 moves from the proximal end 200a towards the distal end 200b of the control assembly 200, i.e., in a distal direction. According to an embodiment, in the first mode, in response to the rotation of the housing 270 in the first direction, the housing 270 is configured to move in the proximal direction, to move the outer sheath 310 in the proximal direction. In response to an actuation input received by the switching element 240, e.g., when the first end 240a of the switching element 240 or the first portion 245a of the frame 245 is pressed, the frame 245 of the switching element 240 moves towards the second end 240b of the switching element 240, thereby disengaging the internal threads 242 from the external threads 218a of the guide rail 210, configuring the first control element 220 in the second mode. Thus, in the second mode the internal threads 242 are disengaged with the external threads 218a of the guide rail 210, enabling the first control element 220 to slide along the surface of the guide rail 210. For example, in the second mode, first control element 220 is configured to slide over the guide rail 210 in the proximal direction or a distal direction, to move the outer sheath 310 in the proximal and distal direction, respectively. In an embodiment, in the second mode, the housing 270 is configured to slide over the guide rail 210 in the proximal or distal direction to move the outer sheath 310 in the proximal or distal direction, respectively. The resilient members remain in a compressed state. In response to the de-actuation of the switching element 240, i.e., when the force is removed from the first end 240a of the switching element 240, the resilient members apply a biased (or biasing) force to move the inner element 243 against the guide rail 210 thereby moving the frame 245 towards the first end 240a, thereby configuring the switching element 240 back in the default position or the first mode. In the first mode, the first control element 220 can be rotated to move gradually and precisely over the guide rail 210 to provide a corresponding precise longitudinal motion to the outer sheath at the time of deployment to gradually expose the stent graft. In the second mode, the first control element 220 can easily slide over the guide rail 210 without engagement of the external threads 218a and the internal threads 242 of the frame 245. This reduces the time required to expose the stent at the time of deployment. Thus, the first mode enables a precise deployment of the stent graft whereas the second mode facilitates a faster deployment of the stent graft. The switching element 240 facilitates easy toggling between the first mode and the second mode based upon the requirement of the procedure. Further, the frame 245 is provided with a notch 245c2 towards the second end 240b of the switching element 240. The notch 245c2 is provided to facilitate easy longitudinal movement of the frame 245 over the guide rail 210. The notch 245c2 also enables smooth movement of the internal threads 242 of the frame 245 over the external threads 218a of the guide rial 210.
[0075] Fig. 18 depicts a coupling between the first control element 220 and the outer sheath 310 with the help of the first hub 260, according to an embodiment. The second cavity 275 of the housing 270 of first control element 220 is configured to receive at least a portion of the first hub 260 to couple the first hub 260 with the housing 270 of the first control element 220. In an embodiment, the first hub 260 includes a body 260a, and a pair of wings 261 extending away from the body 260a. The body 260a is disposed within the cavity 210e of the guide rail 210. The body 260a has a tubular shape having a hollow interior defining a lumen 260b configured to provide a passage to the catheter 300. The first hub 260 is coupled to the outer sheath 310 of the catheter 300. In an embodiment, the proximal end 310a of the outer sheath 310 is coupled to the first hub 260. The lumen 260b of the first hub 260 receives and couples with a proximal portion of the outer sheath 310. The proximal portion of the outer sheath 310 and the first hub 260 may be coupled using a coupling technique, such as, without limitation, chemical bonding, fusion, mechanical joint, etc. In an embodiment, the outer sheath 310 coupled to the first hub 260 using chemical bonding.
[0076] The wings 261 are positioned towards a proximal end of the first hub 260. The wings 261 extend away from the body 260a of the hub 260. Each of the wings 261 is positioned on a corresponding lateral side of the body 260a. In an embodiment, each wing 261 passes through a respective first longitudinal slot 215 provided on the threaded portion 218 of the guide rail 210 and resides within the second cavity 275 of the housing 270 of the first control element 220, thereby engaging the first hub 260 with the first control element 220 and the guide rail 210. In response to the longitudinal motion of the first control element 220, the first hub 260 and the outer sheath 310 are configured to move longitudinally. The direction of motion of the first hub 260 and the outer sheath 310 corresponds to the direction of the longitudinal motion of the first control element 220. That is, the housing 270, in the first mode of the first control element 220, moves longitudinally in the proximal direction in response to rotation of the hosing 270 in the first direction (as explained earlier) to move the outer sheath 310 in the proximal direction. Further, the housing 270, in the second mode of the first control element 220, slides longitudinally in the proximal direction to move the outer sheath 310 in the proximal direction. The movement of the outer sheath 310 in the proximal direction exposes the stent graft as explained earlier. The first hub 260 may be made of a material including, but not limited to ABS, polycarbonate, etc. In an embodiment, the first hub 260 is made of polycarbonate.
[0077] Additionally, or optionally, the first hub 260 may include a pair of grooves 264 provided on the body 260a on each of a top and a bottom end of the first hub 260. Each of the grooves 264 is configured to engage with a corresponding rail 219 of the rails 219 provided within the cavity 210e of the guide rail 210. Each rail 219 at least partially extends into the corresponding groove 264 thereby engaging the first hub 260 with the guide rail 210. The engagement between the rails 219 of the guide rail 210 and the grooves 264 of the first hub 260 prevents any relative rotational motion between the first hub 260 and the guide rail 210, facilitating a smooth longitudinal motion of the first hub 260 along with the outer sheath 310 within the guide rail 210.
[0078] Additionally, or optionally, the control assembly 200 may include a third tube 250 (shown in Fig. 2). The third tube 250 may be disposed within the cavity 210e of the guide rail 210. The third tube 250 is disposed between the outer sheath 310 and the second tube 340. The outer sheath 310 may be configured to slide over the third tube 250. In an embodiment, the third tube 250 extends for a partial length of the guide rail 210. A distal end of the third tube 250 resides in the lumen 260b of the second hub 260. The third tube 250 includes a lumen (not shown) configured to provide passage to the second tube 340. The third tube 250 allows the outer sheath 310 to slide over its outer surface smoothly, enabling easier and smoother longitudinal movement of the outer sheath 310. In other words, the outer sheath 310 is slidable over the third tube 250. The outer diameter of the third tube 250 may be designed such that the outer sheath 310 and the first hub 260 are slidable over the outer surface of the third tube 250. In an embodiment, the third tube 250 may be made of a metal, such as, without limitation, stainless steel (e.g., SS316L or SS304L), nitinol, etc. In an example implementation, the third tube 250 is made of SS316L.
[0079] Referring to Fig. 19, the second control element 280 is positioned towards the proximal end 200a of the control assembly 200. The second control element 280 is coupled to the first tube 330. The second control element 280 is configured to control the longitudinal motion of the first tube 330 of the catheter 300 and helps in releasing the stent graft from the delivery system 100. According to an embodiment, the second control element 280 is coupled to the guide rail 210 and is configured to slide over the guide rail 210 in the proximal direction to move the first tube 330 and the holding element 350 in the proximal direction. In an embodiment, the second control element 280 is disposed over an outer surface of the proximal portion 210a of the guide rail 210. Figs. 22a and 22b illustrate the second control element 280, according to an embodiment. In an embodiment, the second control element 280 has a circular shape, having a hollow interior, defining a second lumen 281 configured to receive the proximal portion 210a of the guide rail 210. The second control element 280 may have any other suitable shape including, but not limited to hexagonal, pentagonal, elliptical, etc. The second control element 280 may be made of a material including, but not limited to ABS or polycarbonate, etc. In an embodiment, the second control element 280 is made of polycarbonate. The second control element 280 is configured to slide over an outer surface of the distal portion 210b of the guide rail 210 to provide a corresponding sliding motion to the first tube 330 of the catheter 300. The operator may hold and slide the second control element 280 in a longitudinal direction. In an embodiment, the second control element 280 houses a second hub 290. The second control 280 element includes a cavity 282 configured to receive a portion of the second hub 290.
[0080] Referring to Fig. 23, in an embodiment, the second hub 290 has a tubular shape having a hollow interior defining a cavity 290a1 (shown in Fig. 23) configured to provide a passage to the inner tube 320 of the catheter 300. The second hub 290 is disposed in the cavity 210e of the guide rail 210 and is coupled to the first tube 330 and the second control element 280. In an embodiment, the second hub 290 includes a body 290a and a pair of flanges 291 extending away from the body 290a. Each flange 291 is positioned towards a corresponding lateral side of the second hub 290. The body 290a resides within the cavity 210e of the guide rail 210. Each of the flanges 291 passes through the respective second longitudinal slot 217 of the guide rail 210, and resides in the cavity 282 of the second control element 280, thereby engaging the second hub 290 with the guide rail 210 and the second control element 280. In an embodiment, the second hub 290 is coupled with the first tube 330 of the catheter 300. The body 290a of the second hub 290 includes a cavity 290a1 configured to receive the proximal end 330a of the first tube 330. The second hub 290 may be coupled to the first tube 330 using a coupling technique, such as, without limitation, chemical bonding, fusion, mechanical joint, etc. In an embodiment, the first tube 330 is coupled to the second hub 290 using chemical bonding. The first tube 330 is configured to moves longitudinally in response to the longitudinal motion of the second control element 280. The second control element 280 is configure to slide over the guide rail 210, specifically, over the proximal portion 210a of the guide rail 210. The second control element 280 may be slid towards the proximal end 100a of the delivery system 100 to move the first tube 330 and the holding element (350) longitudinally to release the stent graft from the delivery system 100. For example, in response to the movement of the second control element 280 in the proximal direction, the second hub 290 is configured to move in the proximal direction to move the first tube 330 and the holding element 350 in the proximal direction. The proximal movement of the holding element 350 causes the stent graft to be released from the delivery system 100 as explained earlier.
[0081] In an embodiment, the control assembly 200 includes a locking member 230. The locking member 230 is configured to restrict the motion of the second control element 280, for example, in the proximal direction. The locking member 230 eliminates any chances of accidental movement of the second control element 280, preventing pre-mature release of the stent graft from the delivery system 100. The locking member 230 is removably coupled to the guide rail 210, more specifically, to the proximal portion 210a of the guide rail 210. When coupled with the guide rail 210, the locking member 230 is disposed over the proximal portion 210a of the guide rail 210, between the second control element 280 and a rim 214 of the guide rail 210 (shown in Fig. 20) provided at the proximal end of the guide rail 210. Thus, the locking member 230 is positioned proximal to a proximal end of the second control element 280. The locking member 230 locks the position of the second control element 280 on the guide rail 210 and prevents the second control element 280 from moving in the proximal direction, thereby avoiding unintended release of the stent graft from the delivery system 100. In other words, when coupled to the guide rail 210 (or the proximal portion 210a of the guide rail 210), the locking member 230 is configured to restrict the movement of the second control element 280 in the proximal direction. Further, the locking member 230 may be removed from the proximal portion 210a of the guide rail 210 to unlock the second control element 280, allowing the operator to slide the second control element 280.
[0082] Referring to Fig. 23, the locking member 230 includes a body 230a and a gripping portion 233. The body 230a of the locking member 230 has a tubular shape. The body 230a includes a longitudinal slit 231 extending from a proximal end to a distal end of the body 230a. The body 230a is coupled to the gripping portion 233. In an embodiment, the body 230a of the locking member 230 at least partially encircles the proximal portion 210a of the guide rail 210. In other words, the body 230a includes an aperture 232 configured to receive the proximal portion 210a of the guide rail 210. In an embodiment, the griping portion 233 may be integrally formed (i.e., integrally coupled) with the body 230a using a fabrication technique including but not limited to molding or casting. Alternatively, the gripping portion 233 may be fixedly coupled to the body 230a of the locking member 230 using a coupling technique, such as, without limitation, chemical bonding, welding, etc. In an embodiment, the gripping portion 233 is welded to the body 230a of the locking member 230. The gripping portion 233 extends away from the body 230a of the locking member 230. The griping portion 233 allows the operator to easily grip the locking member 230 and manipulate the locking member 230 to engage or disengage the locking member 230 from the guide rail 210. For example, to disengage the locking member 230 from the guide rail 210, the gripping portion 233 is pulled, thereby pulling body 230a of the locking member 230 from the guide rail 210. The slit 231 allows expansion of the aperture 232 of the body 230a, facilitating disengagement from the guide rail 210. Further, to engage the locking member 230 from the guide rail 210, the body 230a is pushed against the proximal portion 210a of the guide rail 210, slit facing the proximal portion 210a. The slit 231 allows expansion of the aperture 232 of the body 230a to encircle the proximal portion 210a of the guide rail 210, facilitating engagement with the guide rail 210. The locking member 230 may be made of a material including, but not limited to ABS, polycarbonate, nylon, etc. In an embodiment, the locking member 230 is made of polycarbonate. The structure of the locking member 230 as disclosed herein is merely exemplary. The locking member 230 may include any other structure, which is capable of restricting the proximal movement of the second control element 280, and the same is within the teachings of the present disclosure.
[0083] Moving back to Fig. 20, in an embodiment, the control assembly 200 includes a first port 216. The first port 216 is provided towards the proximal end 100a of the delivery system 100. The first port 216 is configured to provide a passage for the guidewire. During a delivery procedure, the guidewire is inserted into the delivery system 100 via the first port 216. The first port 216 is coupled to the proximal end of the inner tube 320. The first port 216 includes threads 216a provided to couple the first port 216 with an injecting device such as a syringe to allow injection of saline solution into the catheter 300 to flush out any debris out of the catheter 300 during the procedure.
[0084] Additionally, or optionally, the control assembly 200 may include a third hub 295 shown in Fig. 24. The third hub 295 is disposed within the cavity 120e of the guide rail 210, for example, proximal to the threaded portion 218 of the guide rail 210. In an embodiment, the third hub 295 has a hollow structure defining a cavity (not shown) configured provide a passage to the inner tube 320, and the first tube 330. In an embodiment, a proximal portion of the third tube 250 is disposed within the cavity of the third hub 295 thereby coupling of the third hub 295 with a proximal end third tube 250. The proximal end of the third tube 250 and the third hub 295 may be coupled using a coupling technique such as without limitation, chemical bonding, slot fit, etc. In an embodiment, the proximal end of the third tube 250 and the third hub 295 are coupled using chemical bonding. The third hub 295 includes a first extension 295a extending towards a top end of the third hub 295 and a second extension 295b extending towards a bottom end of the third hub 295, thus, the third hub 295 has a cross-shape. The first extension 295a and the second extension 295b pass through a respective hole 212 of the pair of holes 212 of the guide rail 210. The first extension 295a and the second extension 295b have a first port 295a1 and a second port 295b1, respectively. In other words, the first extension 295a and the second extension 295b extend away from a longitudinal axis of the third hub 295 and pass through a respective hole 212 provided on the guide rail 210, such that the first port 295a1 and the second port 295b1 are disposed outside the guide rail 210. The first port 295a1 and the second port 295b1 may be configured to couple with the injecting device (e.g., a syringe) to inject a saline solution into the delivery system 100 during the delivery procedure to flush out any debris or clot of blood from the delivery system 100. In an embodiment, the first port 295a1 and the second port 295b1 are fluidically coupled to a space between an inner surface of the second tube 340 and an outer surface of the first tube 330. The said space provides a passage to the saline solution for flushing.
[0085] Fig. 27 depicts a flow chart of an exemplary method 2700 of using the delivery system 100 to deliver a stent graft 10.
[0086] At step 2701, the stent graft 10 is assembled with the delivery system 100. The stent graft 10 is crimped to a radially collapsed state and mounted on the first tube 330 between the holding element 350 and the stopper 341 of the second tube 340. The stent graft 10 remains enclosed within the outer sheath 310 in a crimped state. The filament loops or the cells of the stent graft 10 are engaged on the holding element 350 as explained earlier, helping to securely couple the stent graft 10 with the delivery system 100.
[0087] At step 2703, the catheter 300 is inserted into a patient’s body via an appropriate vascular access point, e.g., through the transfemoral groin of a patient and navigated through the patient’s vasculature to a target site. A guidewire (not shown) disposed within the lumen of the inner tube 320 is used to navigate the catheter 300 to the target site. At this stage, the outer sheath 310 and the first control element 220 are at a respective distal-most position. As a result, the outer sheath 310 fully covers the stent graft 10 and the stent graft is in the undeployed state. Fig. 28 depicts the configuration of the control assembly 200, specifically, the first control element 220 at the undeployed state. The stopper 341 restrains the stent graft 10 and prevents the stent graft 10 from sliding towards the proximal end 100a of the delivery system 100.
[0088] At step 2705, once the catheter 300 is positioned at the target site, (e.g., thoracic aorta), the outer sheath 310 is retracted using the first control element 220. At this stage, the first control element 220 is in the first mode. The first control element 220 may be rotated in an anti-clockwise direction to move the first control element 220 towards the proximal end 100a of the delivery system 100, thereby retracting the outer sheath 310 towards the proximal end 100a and exposing the stent graft 10. The exposed portion of the stent graft 10 radially expands. Figs. 28a and 28b depict the stent graft 10 in a partially deployed state and the configuration of the first control element 220 at the partially undeployed state. Once the stent graft 10 is partially exposed, to speed up the process, the switching element 240 may be pressed to disengage the threads of the first control element 220 and guide rail 210. Thereafter, the first control element 220 is slid over the guide rail 210 to quickly retract the outer sheath 310 to its proximal most position and expose the entire length of the stent graft 10 out of the outer sheath 310. As a result, the stent graft 10 radially expands completely, i.e., the stent graft 10 is in a fully expanded state. Since the filament loops or cells remain engaged with the holding element 350, the stent graft 10 remains engaged with the delivery system 100. The position of the stent graft 10 may be adjusted, if needed, by moving the delivery system 100.
[0089] At step 2707, once the operator determines that the stent graft 10 is correctly implanted at the target site, the locking member 230 is removed from the guide rail 210 to free the second control element 280 to move. Fig. 28c depicts the control assembly 200 with the locking member 230 disengaged from the guide rail 210.
[0090] At step 2709, the first tube 330 is retracted by sliding the second control 280 towards the proximal end 100a of the delivery system 100 to move the holding element 350 towards the proximal end 100a of the delivery system 100. This results in release of the loops or cells of the stent graft 10 from the holding member 350 (as explained earlier), thereby detaching the stent graft 10 from the delivery system 100 (shown in Fig. 28d). The delivery system 100 can then be pulled back to deploy the stent graft at the deployment site.
[0091] At step 2711, the catheter 300 is withdrawn from the patient’s body.
[0092] The structure of the first control element 220 and its coupling with the outer sheath 310 with the help of the first hub 260 as described herein should be considered as exemplary. The control assembly 200 may include any other suitable structure and may be coupled to the outer sheath 310 using any other manner such that the first control element 220 is configured to move the outer sheath 310 longitudinally in a proximal direction to release the stent graft, and the same is within the teachings of the present disclosure. Further, the structure of the switching element 240 as disclosed herein is merely exemplary. The switching element 240 may have any other structure which is configured to toggle the first control element 220 between the first mode and the second mode, and the same is within the teachings of the present disclosure. It is to be noted that the switching element 240 may be optional. That is, in an embodiment, the first control element 220 may be provided with no switching element 240.
[0093] Further, the braided layer 243 provided in the second tube 340 may be optional, i.e., in some embodiments, the catheter 300 may include the second tube 340 without the braided layer 243.
[0094] The delivery system of the present invention offers several advantages. The easy operation of the first control element and the second control element 280 reduces the time required for the procedure. Additionally, the switching element provides an easy means to toggle between the first mode and second mode of operation of the first control element. The first mode of the first control element allows a granular control over the longitudinal movement of the outer sheath to precisely control exposure of the stent graft. The second mode of first control element helps to speed up the process of retraction of the outer sheath, reducing the procedure time since the first control element can be directly slid over the guide rail without a need for rotating it. The locking member eliminates any chances of unintended movement of the second control element, preventing unwanted or premature release of the stent graft from the delivery system, thereby improving the efficacy of the procedure.
[0095] The scope of the invention is only limited by the appended patent claims. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the teachings of the present invention is/are used. , Claims:We Claim
1. A delivery system (100) for delivering a stent graft, the delivery system (100) comprising:
a. a catheter (300) comprising:
i. a first tube (330); and
ii. a holding element (350) coupled to a distal end (330b) of the first tube (330) and configured to engage with a stent graft mounted on the first tube (330); and
b. a control assembly (200), coupled to the catheter (300), comprising:
i. a second control element (280) coupled to the first tube (330) and configured to move the first tube (330) and the holding element (350) longitudinally to release the stent graft; and
ii. a locking member (230) configured to restrict movement of the second control element (280).
2. The delivery system (100) as claimed in claim 1, wherein the control assembly (200) comprises a guide rail (210), wherein:
a. the second control element (280) is configured to slide over the guide rail (210);
b. in response to longitudinal movement of the second control element (280) in a proximal direction, the first tube (330) and the holding element (350) are configured to move longitudinally in the proximal direction to release stent graft; and
c. the locking member (230) is removably coupled to the guide rail (210) and, when coupled to the guide rail (210), the locking member (230) is configured to restrict movement of the second control element (280) in the proximal direction.
3. The delivery system (100) as claimed in claim 2 wherein the control assembly (200) comprises a second hub (290) disposed in a cavity (210e) of the guide rail (210) and coupled to the first tube (330) and the second control element (280), wherein in response to the movement of the second control element (280) in the proximal direction, the second hub (290) is configured to move in the proximal direction, to move the first tube (330) in the proximal direction.
4. The delivery system (100) as claimed in claim 3, wherein the second hub (290) comprises:
a. a body (290a) disposed within the cavity (210e) of the guide rail 210; and
b. a cavity (290a1) provided in the body (290a) and configured to receive a proximal end (330a) of the first tube (330); and
c. a pair of flanges (291) extending away from the body (290a), each flange (291) is configured to pass through a respective second longitudinal slot (217) provided on the guide rail (210) and reside in a cavity (282) of the second control element (280).
5. The delivery system (100) as claimed in claim 2, wherein the locking member (230) is disposed over a proximal portion (210a) of the guide rail (210), and is positioned proximal to a proximal end of the second control element (290), the locking member (230) comprises:
a. a body (230a) comprising an aperture (232) configured to at least partially encircle the proximal portion (210a) of the guide rail (210); and
b. a gripping portion (233) coupled to the body (230a).
6. The delivery system (100) as claimed in claim 5, wherein a slit (231) is provided longitudinally on the body (230a), the slit (231) is configured to allow expansion of the aperture (232) of the body (230a).
7. The delivery system as claimed in claim 1, wherein the holding element (350) comprises a plurality of extensions (355), each extension 355 is configured to engage with a corresponding filament cell or loop of the stent graft, wherein in response to movement of the holding element (350) in a proximal direction, the extension (355) is configured to disengage from the corresponding filament cell or loop, to release the stent graft.
8. The delivery system (100) as claimed in claim 7, wherein the delivery system (100) comprises a tip member (400) provided at a distal end (100b) of the delivery system (100), wherein the extensions (355) are configured to rest on an outer surface of a proximal portion (410) of the tip member (400), wherein each of the filament cells or loops of the stent graft are disposed between the outer surface of the proximal portion (410) and an inner surface of the corresponding extension (355).
9. The delivery system (100) as claimed in claim 8, wherein the catheter (300) comprises an inner tube (320) disposed within the first tube (330) and coupled to the tip member (400).
10. The delivery system (100) as claimed in claim 1 wherein the holding element (350) comprises an aperture (357) configured to receive, and coupled with, a distal end (330b) of the first tube (330).
11. The delivery system (100) as claimed in claim 1, wherein:
a. the catheter (300) comprises an outer sheath (310) configured to accommodate the stent graft; and
b. the control assembly (200) comprises a first control element (220) coupled to the outer sheath (310) and configured to move the outer sheath (310) longitudinally in the proximal direction to expose the stent graft.
12. The delivery system (100) as claimed in claim 10, wherein the control assembly (200) comprises a first hub (260) coupled to the outer sheath (310) and a housing (270) of the first control element (220), and configured to move longitudinally in the proximal direction, in response to the proximal movement of the housing (270).
13. The delivery system (100) as claimed in claim 10, wherein the first control element (220) comprises a switching element (240) configured to toggle the first control element (220) between a first mode and a second mode, wherein, in the first mode, the first control element (220) is threadedly coupled to the guide rail (210) and wherein, in the second mode, the first control element (220) is configured to slide over the guide rail (210).
14. The delivery system (100) as claimed in claim 1, wherein the catheter (300) comprises:
a. a second tube (340) disposed within the outer sheath (310); and
b. a first tube (330) disposed within the second tube (340); and
c. a stopper (341) coupled to a distal end (340b) of the second tube (340) and configured to restrict a proximal portion of the stent graft mounted on the first tube (330) between a distal end (330b) of the first tube (330) and the distal end (340b) of the second tube (340).
15. The delivery system (100) as claimed in claim 14, wherein the second tube (340) comprises a braided layer (343) comprising a plurality of filaments braided to form a braided structure.