Patent Description:
A number of vascular devices have been developed for replacing, supplementing, or excluding portions of blood vessels. These vascular devices include endoluminal vascular prostheses and stent grafts. Aneurysm exclusion devices are used to exclude vascular aneurysms and provide a prosthetic lumen for the flow of blood. Vascular aneurysms (abnormal dilation of a blood vessel) are usually the result of disease or a genetic predisposition, which can weaken the arterial wall and allow it to expand. Aneurysms can occur in any blood vessel, but most occur in the aorta and peripheral arteries, with the majority of aneurysms occurring in the abdominal aorta or the aortic arch. An abdominal aortic aneurysm typically begins below the renal arteries and extends into one or both of the iliac arteries. A thoracic aortic aneurysm typically occurs in the ascending or descending aorta.

Stent grafts for use in aortic aneurysms typically include a support structure supporting woven or interlocked graft material. Examples of woven graft materials are woven polymer materials, e.g., Dacron, or polytetrafluoroethylene (PTFE). Interlocked graft materials include knit, stretch, and velour materials. The graft material is secured to the inner or outer diameter of the support structure, which supports the graft material and/or holds it in place against a vessel wall. The stent graft is secured to a vessel wall above and below the aneurysm. An open crown without the graft material can be located above the aneurysm to provide a radial force to engage the vessel wall and seal the stent graft to the vessel wall.

<CIT> describes a stent graft delivery system. <CIT> describes a control module for delivery systems.

In one example (not forming part of the claimed subject matter), the present disclosure provides a stent graft delivery system. The stent graft delivery system comprises an inner lumen including an elongate inner lumen body and an inner lumen tip at a distal longitudinal end of the inner lumen body. A stent graft is positionable over the inner lumen. A stent graft cover is slidably positionable over the stent graft and the inner lumen. The stent graft cover is configured to retract proximally to expose a longitudinal portion of the stent graft. The stent graft cover includes an elongate cover body having a distal longitudinal end. A thermal stent graft cutter is coupled to the stent graft cover at the distal longitudinal end of the cover body and is configured to selectively generate and direct heat distally outward from the distal longitudinal end of the cover body to circumferentially cut the stent graft and shorten the length of the stent graft to a desired length.

The invention relates to a a stent graft delivery system. The stent graft delivery system comprises an inner lumen including an elongate inner lumen body and an inner lumen tip at a distal longitudinal end of the inner lumen body. A stent graft is positionable over the inner lumen. A stent graft cover is slidably positionable over the stent graft and the inner lumen. The stent graft cover is configured to retract proximally to expose a longitudinal portion of the stent graft. The stent graft cover includes an elongate cover body having a distal longitudinal end. A thermal stent graft cutter is coupled to the inner lumen and configured to selectively generate and direct heat from inner lumen tip to circumferentially cut the stent graft and shorten the length of the stent graft to a desired length.

In one example (not forming part of the claimed subject matter), the disclosure provides a method of delivering a stent graft to a treatment site within a subject. The method comprises inserting an assembled stent graft delivery system into a lumen of a subject. The assembled stent graft delivery system comprises: an inner lumen including an elongate inner lumen body and an inner lumen tip at a distal longitudinal end of the inner lumen body; a stent graft positionable over the inner lumen; a stent graft cover slidably positionable over the stent graft and the inner lumen; and a thermal stent graft cutter coupled to at least one of the stent graft cover at a distal longitudinal end of the cover body and the inner lumen tip. The stent graft cover is retracted to expose a longitudinal portion of the stent graft. The thermal stent graft cutter is activated to generate and direct heat to circumferentially cut the stent graft outside the stent graft cover and shorten the length of the stent graft to a desired length.

The present disclosure relates to a stent graft delivery system including a stent graft and a stent graft cutter that is configured to allow a user to selective shorten, if desired, a stent graft to a desired length in vivo or in vitro. While these systems and methods are suitable for use in treating abdominal aortic aneurysms and thoracic aortic aneurysms (broadly, treatment sites), those skilled in the art will appreciate that the stent graft delivery system and teachings herein could be used to deliver other types of stent grafts for other vessels as well.

In general, described embodiments of the stent graft delivery system include an inner lumen or shaft (may also be referred to as a runner) having a tip, a stent graft positionable over the inner lumen, and a stent graft cover having a distal longitudinal end and being slidably positionable over the stent graft. In one or more embodiments, a stent graft cutter (e.g., a thermal cutter) is disposed at the distal longitudinal end of the stent graft cover and/or at the inner lumen tip so that cutting of the stent graft to its desired length is performed outside or inside the stent graft cover. In one or more embodiments, the inner lumen tip is used during the cutting operation to sandwich the stent graft between the inner lumen tip and the distal longitudinal end of the stent graft cover. In one more embodiments, a safety system is configured to detect a parameter of the inner lumen tip relative to the distal longitudinal end of the stent graft cover and determine when it is suitable to allow operation of the cutter to cut the stent graft to a desired length.

Referring to <FIG>, one embodiment of a stent graft delivery system is generally indicated at reference numeral <NUM>. The stent graft delivery system <NUM> includes an inner lumen, generally indicated at <NUM>; a stent graft, generally indicated at <NUM>, positionable over the inner lumen, and a stent graft cover, generally indicated at <NUM>, slidably positionable over the stent graft <NUM>. The stent graft delivery system <NUM> further includes a stent graft cutter <NUM> configured to selectively cut the stent graft <NUM> to shorten the length of the stent graft in vivo to a desired length. In one embodiment, a stent graft cutter <NUM> is located at a distal longitudinal end, generally indicated at <NUM>, of an elongate body <NUM> of the stent graft cover <NUM>. In another embodiment, a stent graft cutter <NUM>' is located within an elongate body <NUM>' of a stent graft cover <NUM>'. In at least one embodiment, the stent graft cutter <NUM>, <NUM>' is a thermal cutter which produces heat of a suitable temperature to cut (e.g., melt) the stent graft <NUM> and fuse the cut end of the stent graft. As explained in more detail below, the inner lumen <NUM> may facilitate cutting of the stent graft <NUM>.

Referring to <FIG> and <FIG>, the inner lumen <NUM> supports the stent graft <NUM> so that the stent graft can be delivered to a treatment site in a vessel. In one embodiment, the inner lumen <NUM> includes an inner lumen nose or tip <NUM> at a distal end of an elongate inner lumen body <NUM>. The illustrated inner lumen tip <NUM> tapers distally to facilitate passage through a vessel. In one example, the inner lumen tip <NUM> has a distal longitudinal portion and a proximal longitudinal portion. A maximum outer diameter of the distal longitudinal portion being greater than the proximal longitudinal portion to define a proximally-facing shoulder <NUM>. In another example, such as shown in <FIG>, the proximal longitudinal portion may be omitted, however, the inner lumen tip still defines a proximally-facing shoulder at the juncture of the inner lumen body <NUM> and the inner lumen tip at a proximal longitudinal end of the tip. The shoulder <NUM> may be configured to oppose and/or substantially abut the distal longitudinal end <NUM> of the stent graft cover <NUM>, as shown in <FIG>, when the inner lumen <NUM> is in its fully retracted position.

The inner lumen body <NUM> is long enough to reach from the treatment site in the vessel to the clinician. In one embodiment, the inner lumen <NUM> can include a guide wire lumen. The inner lumen <NUM> can be made of a single material, or the inner lumen nose <NUM> and the inner lumen body <NUM> can be made of different materials. The inner lumen <NUM> can be made of flexible biocompatible materials. For example, the inner lumen <NUM> can be made of polyurethane, polyethylene, PEBAX, nylon, or the like. The inner lumen nose <NUM> can include a radiopaque additive to provide the clinician with a visible tip when using fluoroscopy guidance to deliver the stent graft within the patient. As described below, for example, the inner lumen <NUM> can include an electrical conductor to electrically connect the thermal cutter <NUM>, <NUM>' to a power source.

Referring to <FIG> and <FIG>, the stent graft <NUM> may include radially expandable stents <NUM> (or struts) spaced apart from one another along a length of the stent graft, and graft material <NUM> supported by the stents <NUM>. In <FIG>, the stent graft <NUM> is shown in its non-expanded or collapsed configuration, generally as it would be configured within the stent graft cover <NUM>. As shown in <FIG>, withdrawing or retracting the stent graft cover <NUM> relative to the stent graft <NUM> allows an exposed portion of the stent graft to radially expand to its expanded configuration. Non-stented portions <NUM> are portions of the stent graft <NUM> without stents <NUM> (e.g., longitudinally extending between adjacent stents and extending circumferentially around the circumference of the stent graft). Any of the non-stented portions <NUM> can be cut with the stent graft cutter <NUM> to shorten the length of the stent graft <NUM>.

In this example, the stent graft <NUM> is a single tube with regularly spaced stents <NUM>. The single tube can be the main stent graft or can be an iliac limb, an aorta extender cuff, or an iliac extender cuff. The stent graft can be of other types and configurations. In another embodiment, the stents <NUM> of the stent graft blank <NUM> are irregularly spaced. In another embodiment, the stent graft <NUM> is a bifurcated tube. In another embodiment, the stent graft <NUM> includes a bare spring extending distally beyond the graft material <NUM> to provide a radial force which engages the vessel wall and seals the stent graft at the vessel wall.

In general, the stent graft <NUM> can be any suitable tubular graft configured to expand open and be in sealing contact with tissue after being implanted at the treatment site, such as in the abdominal aorta, thoracic aorta, or other vessel. In one such example, the stent graft <NUM> may be inserted into the target vessel, positioned across a lesion, and then expanded to bypass the weakened wall of the vessel, thereby preventing rupture of an aneurysm. The stent graft is in contact with the healthy tissue after implantation of the stent graft. The stent graft generally extends across the aneurysm in a vessel to divert flow through the stent graft and relieve the pressure normally applied to the weak aneurysmal wall.

The size and configuration of the stents <NUM> of the stent graft <NUM> depend upon the size and configuration of the vessel to be treated. Some of the individual stents <NUM> can be connected to each other by articulated or rigid joints as long as non-stented portions are provided. The length of the stent graft blank <NUM> may be the length of the aneurysm across which the stent graft will be implanted plus an additional remainder to assure that the stent graft blank <NUM> is longer than the aneurysm.

The stents <NUM> can be self-expanding. The stents <NUM> can be made of can be made of spring steel, stainless steel, titanium, nickel titanium alloys (Nitinol), a polymer or copolymer, a combination of these materials, or other suitable materials. The graft material <NUM> can be any woven or interlocked graft material suitable for stent grafts, such as woven polymer materials, e.g., Dacron polyester, or polytetrafluoroethylene (PTFE), or interlocked graft materials including knit, stretch, and velour materials. In some embodiments, the graft material <NUM> includes components made of collagen, albumin, an absorbable polymer, or biocompatible fiber. Alternatively, the graft material <NUM> is constructed from one or more suitable plastic or non-biodegradable materials.

Referring to <FIG>, the body <NUM> of the stent graft cover <NUM> may be an elongate tube which retains and/or compresses the stent graft blank <NUM> on the inner lumen <NUM> when the stent graft blank <NUM> is being delivered to the treatment site in the patient. The stent graft cover <NUM> may then be retracted to allow the exposed portion of the stent graft <NUM> to expand at the treatment site. The stent graft cover <NUM> may include a radiopaque marker <NUM> adjacent the distal longitudinal end <NUM> to locate the stent graft cover <NUM> in the vasculature and locate the stent graft cutter <NUM> relative to the stent graft <NUM>. The body <NUM> of the stent graft cover <NUM> can be made of flexible biocompatible materials. For example, the body <NUM> can be made of polyurethane, polyethylene, PEBAX, nylon, or the like.

Referring to <FIG> and <FIG>, the stent graft cutter <NUM> disposed within the body <NUM> of the stent graft cover <NUM> is used to cut the stent graft <NUM> to the desired length to form the stent graft. The stent graft cutter <NUM> may be located on the inside circumference of the stent graft cover <NUM> and its distal end may be uncovered by or exposed through the distal longitudinal end <NUM> of the body <NUM>, as shown in <FIG>. The stent graft cutter <NUM> can be molded into the stent graft cover <NUM> or attached to the stent graft cover <NUM> with an adhesive. The adhesive can be any biocompatible, thin, high bonding adhesive.

As shown in <FIG> and <FIG>, an insulating layer <NUM> (e.g., an annular insulating layer) comprising an insulator can be placed between the stent graft cutter <NUM> and the body <NUM> of the stent graft cover <NUM> to protect the stent graft cover <NUM> from heat from the stent graft cutter <NUM> during cutting. Another insulating layer <NUM> can overlie a radially inner surface of the cutter <NUM> to protect the inner lumen <NUM>, specifically the inner lumen body, disposed within the stent graft cover <NUM> radially adjacent the cutter <NUM>. The insulating layer <NUM> may be omitted or configured to allow inner circumferential cutting by the cutter <NUM>. This inner circumferential cutting of the cutter <NUM> may be in addition to or in combination with distal end cutting of the cutter. In one embodiment, a polyxylene polymer such as Parylene can be used as the insulator of the insulating layers <NUM>, <NUM>. The insulator can also be used around the distal end of the stent graft cutter <NUM> to control and direct the heat from the stent graft cutter <NUM> distally outward from the cutter. For example, the insulator can cover most of the stent graft cutter <NUM>, such as <NUM> percent of the surface area of the distal end, leaving a small ring of the stent graft cutter <NUM> exposed, such as <NUM> percent of the surface area. The small ring which is exposed provides the heat to cut the stent graft <NUM>, as explained below.

The stent graft cutter <NUM> can be formed of any material which can generate sufficient heat to cut the stent graft <NUM>, and more specifically, the graft material <NUM>. The stent graft cutter <NUM> can be a single piece or multiple turns of wire. In one embodiment, the stent graft cutter <NUM> is heated with a radiofrequency (RF) source, such as an RF source delivering <NUM> to <NUM> Watts, applying a radiofrequency beam to the stent graft cutter <NUM> from outside the patient. The stent graft cutter <NUM> can be made of any material that can be heated by RF, such as metal or ceramic composites. For example, the stent graft cutter <NUM> can be made of Nitinol, stainless steel, or the like. In another embodiment, the stent graft cutter <NUM> is heated with an electrical current source electrically connected to the stent graft cutter <NUM> passing an electric current through the stent graft cutter <NUM>. The current source <NUM> (<FIG>) can be provided in the handle <NUM> (shown schematically in <FIG>), whereby electrical conductors (e.g., wires or metal bands) run along the stent graft cover <NUM> to the cutter <NUM>. Activation of the current source <NUM> can be controlled by a controller <NUM> (e.g., microprocessor control), and the practitioner can communicate with the controller via an actuator <NUM> on the handle <NUM>. The stent graft cutter <NUM> can be made of any material that can be heated with an electrical current, such as metal or ceramic composites. For example, the stent graft cutter <NUM> can be made of Nitinol, stainless steel, nichrome, or the like, and the current source can be an electrocautery power supply. The combination of stent graft cutter <NUM> and graft material can be selected so that the stent graft cutter <NUM> seals the edge of the graft material when making the cut. Cutting is initiated by the energization of the stent graft cutter <NUM> so that it is heated to circumferentially melt the adjacent graft material that is disposed distally of the cutter.

One method of using the stent graft delivery system <NUM> will now be described with reference to <FIG> for illustrative purposes. The stent graft delivery system <NUM>, such as assembled in <FIG>, is delivered to the treatment site. A guidewire (not shown) may be used to deliver the stent graft delivery system <NUM> to the site. After positioning the stent graft delivery system <NUM> at the treatment site, the practitioner retracts the stent graft cover <NUM> relative to the stent graft <NUM> and the inner lumen <NUM> to expose the stent graft and allow it to expand within the treatment site, as shown in <FIG>. An actuator at a handle (not shown) outside the subject may be used to retract the stent graft cover <NUM>. After determining when a desired length of the stent graft <NUM> is expanded at the treatment site, the practitioner retracts the inner lumen <NUM> within the stent graft cover and relative to the stent graft, as shown in <FIG>. The tip <NUM> of the inner lumen <NUM> is retracted through the expanded stent graft <NUM> until it reaches the distal longitudinal end <NUM> of the stent graft cover <NUM>, whereby a circumferential portion of the stent graft, more specifically a circumferential portion of the non-stented portion <NUM>, is disposed between the shoulder <NUM> of the tip and the stent graft cutter <NUM> at the distal longitudinal end of the stent graft cover, as shown in <FIG>. The shoulder <NUM> of the tip <NUM> may press the stent graft <NUM> against the distal longitudinal end of the stent graft cover <NUM> outside of the stent graft cover. The stent graft cutter <NUM> is then activated to circumferentially cut the stent graft <NUM> outside of the stent graft cover <NUM>. For example, in the illustrated embodiment the thermal stent graft cutter <NUM> is activated, such as by activating electrical current source <NUM> via the actuator <NUM>, to heat the stent graft cutter. As shown in <FIG>, once the stent graft <NUM> is cut, the expanded stent graft is released from the stent graft cover <NUM>, and the inner lumen <NUM> and the stent graft cover <NUM> are retracted together, leaving the expanded stent graft at the treatment site within the patient. In another example, as mentioned above, the stent graft cutter may be disposed within the stent graft cover. In the embodiment shown in <FIG> and <FIG>, the stent graft cover <NUM>' includes an internal shoulder <NUM> at the intersection of proximal and distal inner surfaces <NUM>, <NUM>, respectively, where an inner diameter at the proximal inner surface is less than an inner diameter at the distal inner surface. When the inner lumen tip <NUM>' is retracted, the stent graft <NUM> is sandwiched between a proximal shoulder <NUM> (e.g., proximal longitudinal end) of the inner lumen tip and the internal shoulder <NUM> of the stent graft cover <NUM>'. As illustrated in <FIG>, the stent graft cutter <NUM>' (e.g., an annular thermal cutter) may be disposed adjacent the proximal inner surface <NUM> of the stent graft cover <NUM>' to cut a circumferential portion of the stent graft <NUM> disposed between the outer diameter of the inner lumen tip <NUM>' and the proximal inner surface of the stent graft cover. Alternatively, as also illustrated in <FIG>, the stent graft cutter <NUM>' may be disposed adjacent the internal shoulder <NUM> of the stent graft cover <NUM>' to cut a circumferential portion of the stent graft <NUM> disposed between the proximal shoulder <NUM> (e.g., proximal longitudinal end) of the inner lumen tip <NUM>' and the internal shoulder. The stent graft cutter <NUM>' may be disposed at other locations.

In one or more embodiments, the stent graft delivery system includes a safety system configured to allow activation of the stent graft cutter only when the stent graft is suitably sandwiched between the inner lumen tip and the distal end of the stent graft cover to inhibit inadvertent activation of the cutter and provide for proper cutting of the stent graft. In the illustrated embodiment, a safety system is incorporated in the illustrated stent graft delivery system <NUM>. The safety system may be incorporated in other stent graft delivery systems utilizing other stent graft cutting arrangement and configurations. For example, the safety system can be incorporated into the stent graft delivery system described below. It is understood that the safety system may have other configurations and/or designs configured to determine when the stent graft is suitably sandwiched between the inner lumen tip and the distal end of the stent graft cover.

In one of the illustrated embodiments, shown in <FIG> and <FIG>, the safety system includes at least one sensor <NUM> (e.g., a proximity sensor or pressure sensor) on either or both of the inner lumen tip <NUM> and the distal longitudinal end <NUM> of the stent graft cover <NUM>. For example, in this illustrated embodiment, the sensor is mounted on or in (broadly, coupled to) the inner lumen tip <NUM>. As shown in <FIG>, the sensor <NUM> may be in communication with (e.g., wired or wireless) the controller <NUM>, which can be housed in the handle. The controller <NUM> may be configured to receive the signal from the sensor <NUM> and determine whether the stent graft <NUM> is suitably sandwiched between the inner lumen tip <NUM> and the distal longitudinal end <NUM> of the stent graft cover <NUM> based on the received signal. If the controller <NUM> determines the stent graft <NUM> is suitably sandwiched between the inner lumen tip <NUM> (e.g., the shoulder <NUM>) and the distal longitudinal end <NUM> of the stent graft cover <NUM> based on the received signal, then the controller may be configured to allow activation of the stent graft cutter <NUM>.

In one example, the sensor <NUM> is a proximity sensor configured to provide a signal to the controller <NUM> indicative of the proximity of the sensor and the inner lumen tip <NUM> (e.g., the shoulder <NUM> of the inner lumen tip) to the distal longitudinal end <NUM> of the stent graft cover <NUM> (e.g., the stent graft cutter <NUM>). When the sensor <NUM> is a predetermined longitudinal distance from the distal longitudinal end of the stent cover <NUM>, the signal generated by the sensor <NUM> and received by the controller <NUM> is indicative of the stent graft <NUM> being suitable for cutting, for example, the stent graft is suitably sandwiched between the inner lumen tip <NUM> and the distal longitudinal end <NUM> of the stent graft cover <NUM> or the inner lumen tip is suitably disposed within the stent graft cover <NUM>. In another example, the sensor <NUM> is a pressure sensor configured to provide a signal to the controller <NUM> indicative of the inner lumen tip <NUM> (e.g., the shoulder <NUM> of the inner lumen tip) applying pressure to the distal longitudinal end <NUM> of the stent graft cover <NUM> (e.g., the stent graft cutter <NUM>). When the inner lumen tip <NUM> is applying a predetermined pressure against the distal longitudinal end <NUM> of the stent cover <NUM>, the signal generated by the sensor <NUM> and received by the controller <NUM> is indicative of the stent graft <NUM> being suitably sandwiched between the inner lumen tip and the distal end of the stent graft cover. In another embodiment, the sensor <NUM> may be an impedance sensor or another sensor.

In the example shown in <FIG> and <FIG>, the sensor <NUM> may be disposed adjacent the proximal shoulder <NUM> (e.g., proximal longitudinal end) of the inner lumen tip <NUM>'. The operation of the sensor <NUM> may be substantially the same as described above. As an example, the sensor <NUM> may be configured to indicate to the controller <NUM> when the inner lumen (e.g., inner lumen tip <NUM>') is suitably disposed within the stent graft cover <NUM>' to allow for suitable cutting. For example, the sensor <NUM> may indicate to the controller <NUM> when the stent graft <NUM> is sandwiched between the inner lumen tip <NUM>' and the inner surface (e.g., one of the inner surfaces <NUM>, <NUM>) of the stent graft cover <NUM>'.

The safety system may be incorporated in other stent graft delivery systems utilizing other stent graft cutting arrangement and configurations. For example, the safety system can be incorporated into the stent graft delivery system described below. It is understood that the safety system may have other configurations and/or designs configured to determine when the stent graft is suitably sandwiched between the inner lumen tip and the distal end of the stent graft cover.

A suitable diagram of control system for at least one embodiment of the stent graft delivery system is shown in <FIG>.

Referring to <FIG>, another embodiment of a stent graft delivery system is generally indicated at reference numeral <NUM>. The stent graft delivery system <NUM> includes an inner lumen <NUM>, a stent graft <NUM> positionable over the inner lumen, and a stent graft cover <NUM> slidably positionable over the stent graft <NUM>. In <FIG>, the stent graft delivery system <NUM> is shown with the stent graft cover <NUM> retracted to expose and allow expansion of the stent graft <NUM>, the inner lumen <NUM> in a retracted configuration, and the inner lumen tip <NUM> generally abutting a distal longitudinal end <NUM> of the stent graft cover <NUM> (transparent), and the proximal longitudinal portion of the inner lumen tip being show in section. Other than the differences described hereinafter, the stent graft delivery system may be the same as the stent graft delivery system described above, with the same or like component being indicated by the corresponding reference numerals plus <NUM>.

The main difference between the two embodiments of the stent graft delivery system is that the stent graft cutter <NUM> of the present stent graft delivery system <NUM> is located on the inner lumen tip <NUM> rather than at the distal longitudinal end <NUM> of the stent graft cover <NUM>. Like the first embodiment, the illustrated stent graft cutter <NUM> is a thermal cutter which produces high temperature heat to cut the stent graft <NUM>. In the illustrated embodiment, the thermal cutter <NUM> general opposes the distal longitudinal end <NUM> of the stent graft cover <NUM>. As an example, the thermal cutter <NUM> may be at the shoulder <NUM> of the inner lumen tip <NUM>, which may be at the proximal end of the inner lumen tip, such as shown in <FIG>, or at an intermediate longitudinal location, such as shown in the first embodiment of the stent graft delivery system described above.

Referring to <FIG>, the illustrated cutter <NUM> may include an annular cutter body within the inner lumen tip <NUM>. As shown in <FIG>, an annular layer <NUM> of insulation may be disposed radially between the cutter <NUM> and the inner lumen tip <NUM>. Positive and negative terminals <NUM>, <NUM> may extend longitudinally from the annular cutter body and/or may be electrically connected to respective conductors within the inner lumen tip. As an example, referring to <FIG>, the elongate body <NUM> of the inner lumen <NUM> may include a first conductor <NUM> electrically connected to the negative terminal <NUM>, such as by a jumper <NUM> or in other ways, and a second conductor <NUM> electrically connected to the positive terminal <NUM>, such as by a jumper <NUM> or in other ways. The proximal ends of the first and second conductors <NUM>, <NUM> can be electrically connected to the electrical current source <NUM>, whereby current is selectively delivered to the thermal cutter <NUM> to activate cutting.

Referring to <FIG>, the stent graft <NUM> may be selectively cut using the cutter <NUM> in a manner similar to the first embodiment of the stent delivery system <NUM> described above. In particular, after a desired length of the stent graft <NUM> is expanded at the treatment site, the inner lumen <NUM> is retracted to bring the inner lumen tip <NUM> to the distal longitudinal end <NUM> of the stent graft cover <NUM>. When the stent graft <NUM> is sandwiched between the shoulder <NUM> of the inner lumen tip <NUM> (and the cutter <NUM>) and the distal longitudinal end <NUM> of the stent graft cover <NUM>, the cutter <NUM> may be activated by the practitioner to cut the stent graft. As described above, the stent graft delivery system <NUM> may include the safety system which is employed in a similar manner as described above.

As disclosed above, the thermal cutter may be disposed at other locations on the inner lumen. For example, in <FIG> a thermal cutter <NUM>' is proximal of the shoulder <NUM> of the inner lumen tip <NUM>', such as on the body <NUM>' of the inner lumen or on a proximal portion of the inner lumen tip. In this embodiment, a sensor <NUM> may be disposed on the stent graft cover <NUM>'. The sensor <NUM> is configured to be operated and used in the same manner as the sensor <NUM> described above.

In another example shown in <FIG>, the thermal cutter <NUM>" may be at the proximal shoulder <NUM> (e.g., proximal longitudinal end) of the inner lumen tip <NUM>". This embodiment may be similar in construction and operation to the embodiment of <FIG> and <FIG>, except the thermal cutter <NUM>" is on the inner lumen tip <NUM>", adjacent the proximal shoulder <NUM>, and the sensor <NUM>' may be on the stent graft cover <NUM>" adjacent the internal shoulder <NUM>.

Referring to <FIG>, another example of an inner lumen is generally indicated at reference numeral <NUM>. The inner lumen <NUM> may be incorporated in any of the above-described stent graft delivery systems. The inner lumen <NUM> includes an elongate body <NUM> and an inner lumen tip <NUM> at a distal end of the elongate body. The inner lumen tip <NUM> may include the cutter or the cutter may be at other locations. The elongate body <NUM> may include an outer body portion 314A and an inner body portion 314B received in and extending along the outer body portion. The outer body portion 314A may define one or more openings <NUM> at a distal end portion thereof, such as within a space defined by a proximal end portion of the inner lumen tip <NUM>. A plenum <NUM> for fluid (e.g., gas or liquid) defined by the elongate body <NUM> may be in fluid communication with the openings <NUM>. For example, the plenum <NUM> may be defined by the annular space between the inner body portion 314B and the outer body portion 314A. A proximal end of the plenum <NUM> may be configured to be in fluid communication with a source of fluid (e.g., gas or liquid). For example, the source of fluid may be carbon dioxide or other gas soluble in blood or liquid. The gas, for example, escaping the openings <NUM> forces environmental fluid out of the immediate space around the area where the stent graft is clamped to facilitate a rapid temperature increase and sustained temperatures needed to complete the trimming operation.

Each embodiment and each aspect so defined may be combined with any other embodiment or with any other aspect unless clearly indicated to the contrary. The words used in the specification are words of description rather than limitation, and it is understood that various changes can be made without departing from the scope of the disclosure.

Claim 1:
A stent graft delivery system (<NUM>) comprising:
an inner lumen (<NUM>) including an elongate inner lumen body (<NUM>) and an inner lumen tip (<NUM>) at a distal longitudinal end of the inner lumen body;
a stent graft (<NUM>) positionable over the inner lumen;
a stent graft cover (<NUM>) slidably positionable over the stent graft and the inner lumen, the stent graft cover configured to retract proximally to expose a longitudinal portion of the stent graft, the stent graft cover including an elongate cover body having a distal longitudinal end (<NUM>); and
a thermal stent graft cutter (<NUM>) coupled to the inner lumen and configured to selectively generate and direct heat from the inner lumen tip to circumferentially cut the stent graft and shorten the length of the stent graft to a desired length.