Device for deploying expandable implants

Abstract

Aspects of the present invention relate to a delivery device for positioning an expandable implant for treating BPH within a patient's prostatic urethra. The delivery device includes an inner tube and an outer sleeve movable relative to the inner tube between a retracted position and a deployed position. The outer sleeve surrounds the inner tube, defining an annulus therebetween, and the expandable implant is retained within the annulus when the outer sleeve is in the retracted position.

Description

[Technical field]

[0001] The present disclosure relates to a delivery device for an expandable implant, and a method for using such a device. In particular, but not exclusively, such an implant may be positioned within a patient's prostatic urethra to treat benign prostatic hyperplasia (BPH). Accordingly, aspects of the present invention relate to a delivery device for positioning an expandable implant for treating BPH within the prostatic urethra, and a method for delivering or deploying such an implant. [Background technology]

[0002] BPH is a non-cancerous disease that results in an enlargement of the prostate. The prostate surrounds the section of the urethra that is next to the bladder, called the prostatic urethra. Thus, when the prostate enlarges, it can push inward and exert pressure on the prostatic urethra and bladder neck, making it difficult for urine to drain from the bladder.

[0003] It is known to treat BPH in various ways, including ongoing medication, or surgery in particularly bad cases. However, neither of these approaches are desirable. For example, in the United States alone, more than $5 billion is spent annually on medication to manage BPH. Furthermore, surgical solutions can be particularly invasive and uncomfortable for patients. As a result, there has been a move in the art toward the use of expandable implants or stents that can be inserted into the urethra to respond to, and thus relieve, the inward pressure exerted by the enlarged prostate on the urethra and bladder neck.

[0004] Expandable implants offer a minimally invasive, low-cost solution for treating BPH. However, positioning the implant in the correct location within the urethra can be challenging for clinicians. If the implant is not deployed correctly, it may not provide adequate symptom relief, may fail due to migration or excessive adherence, and retrieving the deployed expander from the patient's body can be difficult and invasive.

[0005] An example of an expandable implant or expander for treating BPH is disclosed in WO2017 / 081326. The expander in WO2017 / 081326 is designed to be positioned within the patient's prostatic urethra between the bladder neck and the external sphincter and expand laterally, thereby exerting a radially outward force on the surrounding walls of the prostatic urethra to relieve the symptoms of BPH.

[0006] Properly positioning an expander within the prostatic urethra can be challenging for clinicians because the expander must be precisely positioned both longitudinally and circumferentially or angularly. For example, the expander should be positioned longitudinally at a location between the bladder neck and the external sphincter and should also be oriented to engage the three lobes of the prostate. If the expander is deployed in the wrong position, for example, by being deployed incorrectly or prematurely, complicated procedures may be required to remove or reposition the expander. As a result, there is a need for a minimally invasive delivery device that allows clinicians to precisely position and deploy an expandable implant within a patient's prostatic urethra.

[0007] WO2017 / 081326 describes a delivery device for delivering an expander to a target site within a body cavity, such as the prostatic urethra. The delivery device comprises an ejection element having a triangular cross-section configured to engage and support the expander. The delivery device may be inserted through the penis into the urethra and advanced along the urethra to the target site. When the clinician is satisfied that the expander is in the correct position, the ejection element is advanced distally, causing the expander to be expelled from the delivery device.

[0008] Even with the aid of the delivery device of WO2017 / 081326, it can be difficult to reliably and accurately position the expander within the patient's prostatic urethra. For example, advancing the ejection element can cause the expander to bounce or jump forward upon deployment, making it difficult to accurately position the expander within the prostatic urethra in both the longitudinal and circumferential directions. Relying on the expander to simply self-position relative to the anatomy due to its expansion can be unreliable and unpredictable.

[0009] Additionally, single-step delivery devices such as those described in WO2017 / 081326 may be susceptible to accidental deployment, and the devices do not allow a clinician to pause or reverse the deployment of the expander if the clinician determines that the expander is not correctly positioned within the target site.

[0010] Mikus et al., US6093194, discloses a stent delivery catheter with outer and inner sheaths and an endoscope that serves as the imaging component within the stent. Provisions are made to orient the stent in the inner sheath. However, the positioning of the endoscope relative to the sheath and stent does not facilitate effective imaging throughout the stent delivery process.

[0011] US6033413, also to Mikus et al., discloses a stent delivery system for use with shape-memory stents, where expansion of the stent occurs when the stent is heated above its austenite transition temperature. The catheter includes a heated fluid system where an endoscope used in the procedure can act as a fluid supply line and as a valve to control the flow of heated fluid to the stent. However, this complex system does not address the challenge of accurately and reliably positioning the stent.

[0012] US 2005 / 0278010 to Richardson et al. discloses a stent delivery system with fiber optic imaging capabilities. Similarly, US 5,749,848 to Jang et al. discloses a catheter system with capabilities for imaging, balloon angioplasty, and guided stent deployment. In either case, the relative positions of the imaging system and the implant do not provide for effective imaging throughout the delivery process.

[0013] US8467854 to Lewis et al., like Richardson and Jang et al. above, discloses a neurovascular interventional device that does not provide effective imaging throughout the delivery process due to the relative positions of the imaging system and the therapeutic device that can deliver the implant, such as a stent. In fact, simultaneous deployment and imaging may not be possible.

[0014] US6926732 to Derus et al. discloses a stent delivery device and method that is said to be usable for various procedures, including the treatment of BPH. The stent is positioned within a casing member for positioning and delivery, but the casing member would block the view of the anatomical structures available through the imaging system of the device. In particular, the anatomical structures cannot be viewed against or along the distal end of the stent or from inside the stent. As a result, when the device is used to treat BPH, the imaging system can only identify the prostatic urethra, but cannot define and show the specific alignment of the stent with the anatomical features.

[0015] US 2012 / 283816 to Jordan et al. discloses a system for delivering and deploying self-expanding stents incorporating a mechanism for retrieving a partially deployed stent. US 2020 / 113719 to Desrosiers et al. also provides for recapture of a partially deployed implant. US 2011 / 301685 to Kao et al. discloses a bidirectional stent delivery system. EP 2745813 to Roeder et al. discloses an intraluminal stent over a guidewire. In both cases, no effective provisions are made for imaging the stent delivery site throughout the delivery process, and stent release and positioning can be unreliable.

[0016] It is an object of the present invention to address one or more of the disadvantages associated with the prior art. Summary of the Invention

[0017] Generally, the present invention provides a delivery device for imaging and positioning an expandable implant within a patient's prostatic urethra when treating BPH. The delivery device includes an inner tube or other elongated element, such as a rod, a tubular outer sleeve movable relative to the inner tube between a retracted position and a deployed position, and an imaging device.

[0018] The outer sleeve surrounds the inner tube and defines an annulus therebetween. When the outer sleeve is in a stored position, the expandable implant is retained within the annulus. In the stored position, the outer sleeve at least partially surrounds the expandable implant such that the implant is retained in the inner tube. Thus, when in the stored position, the outer sleeve prevents the expandable implant from expanding radially. Conversely, in the deployed position, the expander is not covered by the outer sleeve, allowing the expander to expand radially.

[0019] In the retracted position, the imaging device allows the clinician to visualize the expander relative to the anatomy, thereby facilitating the clinician to properly align the expander relative to the anatomy before releasing it from the device. The imaging device may be longitudinally movable relative to the outer sleeve and / or inner tube, or may be fixed against longitudinal movement relative to the outer sleeve and / or inner tube. For example, the outer sleeve and imaging device may be movable together relative to the inner tube between the retracted and deployed positions.

[0020] In general, the invention resides in a delivery device for deploying a self-expanding implant within a body cavity, the device comprising at least one retention array for retaining the implant against axial or circumferential movement, an elongated longitudinally extending outer element radially outward of the or each retention array, and an imaging head disposed on a longitudinal axis extending radially inward of the or each retention array.

[0021] The outer element is longitudinally movable relative to the or each retention array between a retracted position in which the outer element surrounds the implant and retains the implant engaged with the or each retention array or prevents the implant from dislodging from the or each retention array, and a partially deployed position in which the outer element does not cover a distal portion of the implant but surrounds a proximal portion of the implant and continues to retain an implant engaged with the or each retention array.

[0022] Also, the imaging head is proximally retractable between an advanced position when the outer element is in the stored position and a retracted position when the outer element is in the partially deployed position. The imaging head may be configured to define a field of view extending from a vantage point that is radially inward with respect to the or each retention array and therefore also inward with respect to the implant.

[0023] The outer element may also be longitudinally movable relative to the or each retention array to a fully deployed position in which the outer element does not cover a proximal portion of the implant sufficiently to disengage the implant from the retention array for radial self-expansion within the body cavity.

[0024] According to one aspect of the invention, a delivery device for positioning an expandable implant for treating BPH within a patient's prostatic urethra is provided, the delivery tube of the delivery device comprising a first elongate element including or supporting an imaging device, and a second elongate element surrounding the first elongate element and defining an annulus between the first and second elongate elements, the second elongate element retracting relative to the first elongate element between a retracted position in which the second elongate element is configured to surround the implant thereby retaining the implant within the annulus, a partially deployed position in which the second elongate element is configured to partially uncover the implant, and a fully deployed position in which the second elongate element is configured to uncover the implant to a degree sufficient to allow the implant to radially expand within the prostatic urethra.

[0025] When in the stored position, the distal image receiving surface of the imaging device may be locked at or near the distal end of the delivery device, allowing the clinician to view the anatomical structures, preferably with an unobstructed view. When in the partially deployed position, the distal surface of the imaging device may be positioned within the interior of the expander, at a location proximal to the distal tip of the expander, allowing the clinician to view the distal portion of the expander relative to the anatomical structures, thereby facilitating the clinician to align the expander relative to the anatomical structures.

[0026] The first elongate element may be, for example, an inner tube or rod and the second elongate element may be an outer sleeve or tube. The first and second elongate elements may be elliptical, e.g. circular, in cross section, and are preferably cylindrical.

[0027] The delivery devices of the present invention advantageously provide for precise positioning and deployment of an expandable implant for treating BPH within a patient's prostatic urethra. An outer sleeve may retain the expandable implant or expander within the annulus by surrounding the expander and preventing radial expansion of the expander until it is properly positioned within the prostatic urethra.

[0028] In one embodiment, when in the partially deployed position, the distal tip of the outer element and the distal tip or face of the imaging device may be positioned proximally relative to the distal tip of the inner element. Advantageously, the partially deployed position does not cover a portion of the expander while retaining the expander in a compressed or stored configuration on the inner element. This allows the clinician to view the expander relative to the anatomy, thereby facilitating the clinician to align the expander relative to the anatomy. Furthermore, moving the outer element from an intermediate partially deployed position to a fully deployed position involves less longitudinal movement than moving from a stored position to a fully deployed position. This improves the accuracy of the deployment of the expander.

[0029] In one embodiment, the delivery device may include a third elongate element positioned between the first inner elongate element and the second outer elongate element. The third elongate element may be an intermediate tube, such as a steering tube.

[0030] The delivery device may include one or more retention features for inhibiting movement of the expander. The retention features advantageously retain the expandable implant relative to the inner or intermediate tube within the annulus. This advantageously prevents longitudinal or angular movement of the expander relative to the inner or steering tube prior to deployment of the expander. In one embodiment, the retention features may be positioned within the annulus.

[0031] In one embodiment, the outer sleeve may surround the retention feature when in the partially deployed or retracted position, which prevents the expander from radially expanding prior to full deployment of the expander. Additionally, the outer sleeve may be returned from the partially deployed position to the retracted position if the clinician wishes to stop or pause the deployment of the expander.

[0032] The retention feature may, for example, comprise at least one protrusion on the inner element. In one embodiment, the retention feature comprises a proximal protrusion and a distal protrusion positioned on the inner element. A slot for at least partially receiving the expander may be defined between the distal and proximal protrusions. The expander may be received within the slot. For example, the expander may comprise an apex, and one of the protrusions may be positioned between opposing sides of the apex when the expander is positioned on the inner element.

[0033] The inner element may include a set of two, three, or more angularly and / or longitudinally spaced retaining features configured to engage and retain the expander. In another embodiment, the projections may be positioned on or extend distally from the intermediate tube. The projections may be oriented on the inner element or intermediate tube such that the expander is substantially correctly oriented when the delivery device is inserted into the urethra in an upright or otherwise known or predetermined orientation.

[0034] When the outer sleeve is in the retracted or partially deployed position, a gap may be defined between the top or radially outer surface of the retention feature and the radially inner surface of the outer sleeve. The gap is narrower than the radial thickness of the portion of the expander engaged by the retention feature. For example, the delivery device expander may include a wire retained by the retention feature, and the gap may be smaller than the thickness of the wire. The gap beneficially provides clearance between the retention feature and the outer sleeve, allowing the outer sleeve to move freely relative to the inner tube. Additionally, if the annulus forms part of an irrigation channel, the gap may allow fluid to flow along the annulus.

[0035] The delivery device may further comprise a handle connected to a proximal end of the inner and / or outer element to allow the delivery device to be held and gripped by a clinician. Additionally, the handle may be operable to move the outer sleeve and imaging device between a retracted position, a fully deployed position, and a partially deployed position.

[0036] In one embodiment, the handle may include a proximal grip and a distal grip, in another embodiment, the handle may include a two or three finger power grip similar to that of an endoscope, where the middle and / or ring and pinky fingers hold the endoscope handle and the index and / or middle fingers operate the steering and other mechanisms.

[0037] The handle may include a lever, catch, or other latch movable between locked and unlocked positions to act as a detent. When the latch is in the locked position, the outer element is locked in the retracted position. The latch is movable to an intermediate position, allowing the outer sleeve to be moved from the retracted position to the partially deployed position when the lever is in that position. The latch may also be movable to a fully deployed position. When the latch is in the fully deployed position, the outer element can be moved between the partially deployed position and the fully deployed position.

[0038] When the expander is retained within the annulus in use, the distal end of the inner element may be positioned distally or longitudinally aligned with the distal end of the expander, or alternatively, the distal end of the inner element may be positioned proximal to the distal end of the expander and distal to the proximal end of the expander.

[0039] Beneficially, the inner element provides support to the expander when it is held on the inner element such that the longitudinal struts of the expander are maintained in a generally parallel relationship when the expander is in the storage configuration. This advantageously facilitates radial expansion of the expander during deployment and further reduces the likelihood of the expander becoming dislodged from the retention feature. Additionally, the inner element supports the expander when the delivery tube is being inserted into and along the urethra. This advantageously prevents the expander from being further compressed by the urethra, which could otherwise cause the expander to become dislodged from the retention feature.

[0040] The inner element may comprise an inner lumen that may extend along the length of the inner tube. Additionally, the inner lumen may act as an irrigation channel to clear the field of view and drain fluids from the bladder and / or urethra. An imaging device may be received at least partially within the inner lumen, and the inner element may be an imaging device. The imaging device may comprise an imaging tip or optical fiber, and the imaging device may comprise a telescope. For example, the imaging tip may be connected to the imaging device, and wires and a power source connecting the imaging device to an image display device may be passed through the inner lumen. The imaging device may be in a fixed circumferential position relative to the inner element that holds the expander such that the imaging device cannot rotate, thus facilitating precise longitudinal and angular alignment of the implant with the anatomical structure.

[0041] In the stored configuration, all or most of the expander may be positioned proximal to, and therefore outside, the field of view of the imaging device. This is beneficial because the imaging device generates an image of the patient's anatomy to allow the clinician to evaluate the anatomy prior to deployment of the expander. However, the field of view of the imaging device may include at least a portion of the expander when the expander is in the stored configuration on the inner tube. The viewpoint that is the origin of the imaging device's field of view may be from inside the expander. This is beneficial because the imaging device can receive an image of the expander relative to the patient's anatomy. This allows the clinician to accurately locate and position the expandable implant relative to the anatomy using the image from the imaging device.

[0042] The imaging device may, for example, be movable relative to the inner element, but fixed relative to the outer element. Thus, the imaging device may move relative to the inner element as the outer sleeve is moved between a stored position, a partially deployed position, and a fully deployed position. In one embodiment, the imaging device may be fixed relative to the inner and outer elements such that it cannot rotate circumferentially about the central longitudinal axis of the delivery tube. This allows the clinician to precisely position the expandable implant at a specific axial location relative to the anatomy without rotational movement, ensuring accurate deployment.

[0043] In another embodiment, the inner element, and optionally the imaging device, are longitudinally movable relative to the intermediate tube between a distally advanced position and a proximal retracted position. When the inner tube is in the distally advanced position, the distal tip of the inner element may be positioned distally relative to the distal tip of the outer element. When the inner element is in the distally advanced position, the outer element may be outside the field of view of the imaging device. However, the imaging device may be configured such that its field of view captures at least a distal portion of the expander when the inner element is in the proximal retracted position.

[0044] The outer element may include longitudinally spaced apart graduation lines to provide a visual aid to the clinician in positioning the expander in the desired longitudinal position, however, the graduation lines may be on the inner element if the outer element is transparent such that the graduation lines on the inner element are visible to the clinician.

[0045] In one embodiment, the delivery device may include an expandable implant. The implant may be supported by a first elongate element and at least partially covered by a second elongate element.

[0046] The concepts of the present invention extend to a method of deploying a self-expanding implant within a body cavity of a patient, the method including inserting an elongated delivery sheath of an implant delivery system into the cavity with an imaging head of the delivery system in a distally advanced position and the delivery sheath in a retracted position in which the implant is retained within and covered by the delivery sheath, navigating the implant to a target site within the cavity guided by an image of the patient's anatomy taken from a first perspective defined by the distally advanced imaging head, retracting the delivery sheath proximally relative to the implant to a partially deployed position in which the implant is at least partially uncovered but remains retained by the delivery sheath, retracting the imaging head proximally relative to the implant to a retracted position defining a second perspective in which the imaging head is within and surrounded by the implant, and positioning the implant at the target site guided by an image of the implant taken from the second perspective defined by the proximally retracted imaging head relative to the surrounding anatomy.

[0047] The patient's anatomy may be imaged from a first viewpoint, substantially unobstructed by the implant or the delivery sheath. The implant may be imaged relative to the surrounding anatomy from a second viewpoint disposed proximally relative to the distal end of the implant, substantially unobstructed by the delivery sheath. The outer element and imaging head may move together in a proximal direction.

[0048] The present concepts also encompass a method of deploying an expandable implant within a patient's urethra, the method including inserting a delivery tube into the urethra with the implant and an imaging device retained within and covered by the delivery tube, retracting the delivery tube proximally to a partially retracted position where the implant is at least partially uncovered but still retained by the delivery tube, imaging the implant along with the patient's anatomy using the imaging device, positioning the implant at a target site within the urethra, and deploying the implant at the target site by further retracting the delivery tube sufficiently to release the implant from the delivery tube.

[0049] More specifically, the delivery tube images the anatomy with a camera or other image sensor located within the innermost channel of the delivery system and within the inner diameter of the implant. In the partially retracted position, the implant can be aligned with the anatomy using a camera that generates images from within the implant. After deploying the implant at the target site by further retracting the delivery tube, the camera can image the device deployed within the anatomy without requiring further manipulation of the handle components by the user.

[0050] Deploying the expander in a two-stage deployment process under direct vision from an imaging device beneficially reduces the risk of the clinician deploying the implant incorrectly. Additionally, the partially retracted position allows for alignment of the implant to the anatomy when the implant is partially uncovered and when the imaging device is positioned within the implant. Imaging the expander with an imaging device positioned within the implant allows for concentric imaging of the expander and anatomy, allowing the alignment step to be completed with the anatomy and expander in the same plane aligned to a central axis, improving the accuracy of deployment.

[0051] Inserting the delivery tube when the implant is covered by the outer sleeve is beneficial as it allows the delivery device to be easily inserted into the urethra without the implant getting caught in the anatomical structures. Advantageously, the delivery tube may have a stiff distal tip portion for manipulating and straightening the prostatic urethra, ensuring that the prostatic urethra, the surrounding anatomical structures, and the expander implant are substantially concentric. Optionally, the delivery tube can steer the implant in response to a control input from its proximal end.

[0052] In one embodiment, the method may include positioning an implant at a target site at a longitudinal location in the urethra between the patient's bladder neck and the external sphincter. The method may include advancing a distal end of a delivery tube along the urethra distally to or beyond the bladder neck. Thus, the distal end of the delivery tube may be advanced into the bladder. This allows visualization of anatomical structures along the length of the urethra as the delivery device advances along the urethra. This allows the clinician to check for any obstructions in the urethra and visualize the prostatic lobes.

[0053] The method may then include retracting the distal end of the delivery tube proximally away from the bladder neck so that the bladder neck may be used as a reference to position the implant in the proper longitudinal position in the prostatic urethra. The delivery tube may include graduation marks where to position the implant in a clinically acceptable position relative to the bladder neck reference prior to deployment.

[0054] Positioning the expandable implant may also include turning or rotating the implant about a longitudinal axis of the delivery tube when positioning the implant at the target site. The implant may be rotated to align the implant with at least one prostate lobe of the patient. For example, the implant may include at least one apex and may be rotated to align the at least one apex with the prostate lobe. The implant may be fixed relative to the delivery tube such that rotating the delivery tube rotates the expander. The method may include aligning at least one apex of the implant with the or each prostate lobe.

[0055] The delivery tube may comprise an inner tube that is stationary relative to the prostatic urethra when the delivery tube is moved from the partially deployed configuration to the fully deployed configuration. The method may include holding the implant substantially stationary relative to the prostatic urethra when further retracting the delivery tube from the partially deployed position to the fully deployed position. This is beneficial because the expandable implant can be secured to the inner tube when in the partially deployed configuration, thus allowing the expander to remain in a substantially unchanged longitudinal position when the delivery device is moved to the fully deployed configuration. This improves the accuracy of deployment of the implant from a stored state to a deployed state within the prostatic urethra.

[0056] Deploying the implant may include radially expanding the implant. The implant may be radially expanded from a stored or compressed state to a deployed or expanded state. The implant may be deployed by longitudinally moving the outer sleeve relative to the implant. Thus, the implant may be desheathed or uncovered to allow the implant to radially expand.

[0057] Moving the delivery tube to the partially deployed configuration may include actuating a safety catch, latch, or button to allow the delivery tube to be so moved or reconfigured. The method may further include actuating the safety catch again, e.g., moving the safety catch to a further position to allow the delivery tube to be further retracted from the partially retracted position.

[0058] The method may include retaining the implant by engagement with a retention arrangement that remains covered by the delivery tube in the partially retracted position but is exposed by said further retraction of the delivery tube to release the implant. The method may further include advancing the delivery tube distally to again cover the retention arrangement prior to removing the delivery tube from the urethra. Thus, the method may include moving the delivery tube from a fully deployed configuration to a stored configuration prior to removing the delivery tube from the urethra.

[0059] The method may include viewing the implant relative to the urethra from a vantage point within the implant and disposed proximally to the implant distal end when the delivery tube is in a partially retracted position.

[0060] The method may include aligning at least one apex of the implant with the patient's verumontanum. The method may include positioning the verumontanum between laterally spaced, longitudinally extending members or struts of the implant. The method may include retracting the implant proximally while avoiding contact of the apex with the verumontanum. The apex of the implant may be aligned with the lateral lobes of the prostate, or the respective lobes that are the transition zone and median lobe.

[0061] The method may further include manipulating the anatomical structure by steering the delivery tube or bending at least a distal portion of the delivery tube along its length.

[0062] The present invention has many advantages, for example, the initial field of view of the imaging device gives an unobstructed view of the anatomy since the implant does not need to be retracted to view when the prostatic urethra is reached, which helps the clinician evaluate the anatomy and make a decision on positioning the implant according to the length of the prostatic urethra and the height of the bladder neck for a particular patient.

[0063] Conversely, the positioning step allows for concentric imaging of the implant and anatomical structure, allowing the alignment step to be completed accurately and easily, and ensuring that the implant and anatomical structure are substantially symmetrical about the same vertical plane and have substantially the same central axis during the deployment step.

[0064] The positioning step thus allows for a view of the implant and the anatomical structure at the same axial position in the anatomy. The camera lens or other image sensor and the distal end of the expander towards the bladder neck are at the same longitudinal position relative to each other, advance in this relative position and are always locked together. This ensures consistent accuracy of positioning as the retention feature on the distal end portion of the delivery system does not allow the implant to move on the delivery system during the introduction and positioning steps.

[0065] Placing a lens or other imaging sensor within the implant facilitates correct positioning of the implant simultaneously relative to each of the key anatomical features: the bladder neck, prostate lobes, and verumontanum. Viewing the implant and anatomical structures in the same plane, rather than from a posterior or lateral perspective of the implant, facilitates alignment accuracy.

[0066] The rigid distal tip of the delivery system straightens the prostatic urethra, ensuring that the expander and the prostatic urethra, and thus the surrounding anatomical structures, are substantially concentric. Thus, a camera lens or other image sensor is oriented and positioned within the implant to usefully image from the inside out. More generally, the steerable tip allows for positioning to conform to the curvature, angle, or inclination of the prostatic urethra. In this regard, embodiments of the present invention combine a steering ring with an implant retention feature in a manner not suggested by the prior art.

[0067] Advantageously, the duration and complexity of the procedure is reduced as no balloon or other positioning device is required within the bladder, and there is no need for deployment and retraction into the bladder, which can cause damage to the bladder neck.

[0068] A simple handle mechanism can affect deployment. The implant is pre-formed, with no need to adjust or form the implant in situ. Parts of the delivery handle lock together and control the movement and engagement of the delivery and imaging sheaths. The delivery sheath has features that hold the implant in a locked position relative to the imaging components. The outer sheath may be sized to move back or not obscure the view of the implant and anatomy during deployment.

[0069] Those skilled in the art will appreciate that although the expanders described herein are for use in treating BPH, the delivery system of the present invention can be used in other applications in which an expandable implant is positioned within a body cavity. [Brief description of the drawings]

[0070] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0071] [Figure 1] FIG. 1 is a perspective view of an expander in an inflated state suitable for use in an embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective view of the expander of FIG. 1 in a stored state. [Diagram 3] FIG. 2 is a cross-sectional view of the prostate and prostatic urethra in which the expander of FIG. 1 is used to treat BPH. [Figure 4] FIG. 1 is a perspective view of a delivery device according to one embodiment of the present invention. [Diagram 5] 5 is a schematic diagram of the distal end of the delivery device of FIG. 4 positioned within the prostatic urethra of a patient. [Figure 6] 5 is a perspective view of the underside of the distal end of the inner tube of the delivery device of FIG. 4. [Figure 7] FIG. 7 is a longitudinal cross-sectional view of the retaining arrangement of the inner tube and the expander of FIG. [Figure 8] 7 is a cross-sectional view of the distal end of the inner tube of FIG. 6. [Figure 9] FIG. 5 is a schematic side view of a handle of the delivery device of FIG. 4. [Figure 10] FIG. 13 is a schematic side view of a distal end region of the delivery tube and expander in a storage configuration. [Figure 11] FIG. 13 is a schematic side view of a distal end region of a delivery tube and an expander in a partially deployed configuration. [Figure 12] FIG. 13 is a schematic side view of the distal end region of the delivery tube and expander in a fully deployed configuration. [Figure 13] FIG. 2 is a schematic end view of a delivery device including an imaging device. [Figure 14] 14 is a schematic diagram of an image captured by the imaging device of FIG. 13. [Figure 15] 5 is a flow chart outlining the steps for deploying an expandable implant using the delivery device of FIG. 4. [Figure 16] 13 is a schematic diagram of a tube of a delivery device according to another embodiment. [Figure 17] FIG. 13 is a perspective view of a delivery device according to a further embodiment of the present invention. [Figure 18] FIG. 18 is a perspective view of the distal tip of the delivery device of FIG. 17. [Figure 19]FIG. 18 is a schematic side view of a distal end region of the steering tube of the delivery device of FIG. 17. [Figure 20] 18 is a schematic diagram of a distal end region of the delivery device of FIG. 17 in a stored configuration. [Figure 21] FIG. 18 is a schematic diagram of the distal tip of the delivery device of FIG. 17 in a partially deployed configuration. [Figure 22] FIG. 18 is a schematic diagram of the distal tip of the delivery device of FIG. 17 in a fully deployed configuration. [Figure 23] FIG. 18 is a perspective view of a handle of the delivery device of FIG. 17. [Figure 24] FIG. 13 is a schematic side view of a distal end region of a steering tube according to another embodiment. [Diagram 25] FIG. 13 is a schematic side view of a distal end region of a steering tube according to another embodiment. [Figure 26] 18 is a flow chart outlining the steps for deploying an expandable implant using the delivery device of FIG. 17. [Figure 27] Shown are three elongated elements of the delivery sheath of a delivery device of the present invention: an imaging sheath with a rigid camera tip, a steering sheath surrounding the imaging sheath, and an outer sheath surrounding the imaging sheath and steering sheath. [Figure 28] 28 is a series of enlarged detailed perspective views showing components of the distal tip portion of the delivery sheath of FIG. 27. [Figure 29] 28 is a selection of enlarged detail views of the distal tip portion of the delivery sheath of FIG. 27, illustrating the change in length of the rigid camera tip of the imaging sheath. [Diagram 30] 28 is a selection view of the implant retaining component and steering / pulling ring assembly of the delivery sheath of FIG. 27. [Diagram 31] 11A-11C are a series of schematic diagrams illustrating the operation of an interlocking mechanism for controlling relative movement of elongate elements of a delivery sheath of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0072] In general terms, embodiments of the present invention relate to a delivery device for deploying an expandable implant or expander within a patient's prostatic urethra to relieve symptoms of BPH. In broad terms, the delivery device comprises a handle operatively connected to an elongated delivery tube. The delivery tube comprises an inner tube surrounded by an outer sleeve or sheath defining an annulus therebetween. The expander may be held in a compressed or stored configuration within the annulus. A retention feature positioned at a distal end region of the inner tube holds the expander relative to the inner tube in a compressed or stored configuration within the annulus. An imaging component is housed in or supported by the inner tube.

[0073] In use, the delivery tube is inserted through the penis into the patient's urethra and advanced along the urethra to the prostatic urethra. When the clinician is confident that the distal end portion, and therefore the expander, is correctly positioned within the prostatic urethra, the clinician operates the handle to retract the outer sheath, thereby allowing the expander to expand and deploy within the prostatic urethra.

[0074] Deployment of the expander from the delivery device may be a two-step process in which the outer sheath is first retracted to a partially deployed position, in which the expander is at least partially desheathed but remains attached to the delivery device. When the clinician is confident that the expander is correctly positioned after the imaging and positioning steps, the outer sheath may be moved to a fully deployed position to release the expander from the delivery device, thereby positioning the expander at a target site within a body cavity, in this example the prostatic urethra.

[0075] The delivery device advantageously allows for the expander to be precisely positioned within the anatomy before being deployed within the prostatic urethra in a controlled manner under direct vision. Controlled deployment advantageously prevents inadvertent deployment of the expander and ensures that the expander is precisely positioned within the prostatic urethra during and after deployment.

[0076] To place the embodiments of the present invention in a suitable context, reference is first made to Figure 1, which illustrates a schematic diagram of an expandable implant or expander 10 suitable for use with embodiments of the present invention. The skilled reader should be aware that the expander 10 illustrated in Figure 1 is by way of example only, and that the delivery devices described herein may be suitable or adapted for use with other implants.

[0077] The expander 10 comprises a single Nitinol wire arranged to form a sinusoidal ring. The expander 10 may move or deform elastically between an expanded or deployed state, as shown in FIG. 1, and a compressed or stored state, as shown in FIG. 2. Upon release, the expander 10 moves or deforms itself from the compressed or stored state of FIG. 2 to the expanded or deployed state of FIG. 1 by elastic recovery. Specifically, the Nitinol wire ring of the expander 10 acts with superelastic shape memory properties such that when in a compressed state, the expander 10 exerts an outward radial force that urges itself to the expanded state.

[0078] The expander 10 has a proximal end 16 with three proximal prongs 17 with respective apexes 18, and a distal end 13 with three distal prongs 14 with respective apexes 15. The apexes 15, 18 of the distal end 13 and proximal end 16 are joined by longitudinal struts 19 in alternating circumferential directions.

[0079] When the expander 10 is in the contracted or compressed state shown in Figure 2, the diameter of the sinusoidal ring defined by the expander 10 is shortened so that the expander 10 may be advanced along the patient's urethra with minimal discomfort. The expander 10 is delivered to the prostatic urethra 30 in its contracted or delivery state.

[0080] 3, there is shown an expander 10 being used to treat benign prostatic hyperplasia (BPH) within the prostate gland 11. In use, the expander 10 is positioned within the prostatic urethra 30 between the bladder neck 32 and the external sphincter muscle 33. When positioned in this position, the expander 10 exerts an outward radial force against the surrounding walls of the prostatic urethra 30 to facilitate the flow of urine from the bladder 36.

[0081] Positioning the expander 10 in the correct longitudinal position between the bladder neck 32 and the external sphincter 33 can be difficult, and care must be taken to ensure that the expander 10 is properly positioned before deployment. Positioning the expander 10 too close to either the bladder neck 32 or the external sphincter 33 is undesirable, as those muscle actions can cause the expander 10 to migrate over time.

[0082] 3, the expander 10 is angularly oriented such that the verumontanum 25 and vas deferens 34 are not obstructed by the wires of the expander 10, thus preserving the patient's sexual function. Additionally, the longitudinal struts 19 of the expander 10 are oriented to engage respective lobes of the prostate 11, thereby exerting an outward radial force on each lobe to maintain an open passage between the bladder neck 32 and the external sphincter 33.

[0083] 4, a delivery device 40 for positioning the expander 10 within the prostatic urethra 30 is shown. The delivery device 40 includes a handle 46 operably connected to an elongated delivery tube 42. The delivery tube 42 is configured to at least partially receive the expander 10 in a compressed state and deploy the expander 10 within the patient's prostatic urethra 30. The delivery tube 42 may be inserted into the urethra via the patient's penis and advanced along the urethra to a target site, in this example, the prostatic urethra 30, where the expander 10 may be deployed.

[0084] 5 shows a schematic diagram of the distal end portion 44 of the delivery tube 42 positioned within the prostatic urethra 30. As shown in FIG. 5, the delivery tube 42 comprises an inner tube 50 surrounded by an outer sleeve 48. An annulus 85 is defined between the inner tube 50 and the outer sleeve 48, and the expander 10 is positioned within the annulus 85. The outer sleeve 48 surrounds the expander 10, thereby preventing the expander 10 from expanding from a stored configuration to a deployed configuration. The annulus 85 functions to retain the expander 10 at the distal end region 44 of the delivery tube 42 and further acts as an irrigation channel through which fluid may be irrigated to or from the urethra and / or bladder 36.

[0085] The handle 46 is operably coupled to the delivery tube 42 such that by operating the handle 46, the clinician can move the outer sleeve 48 longitudinally relative to the inner tube 50. A lumen 70 on the inner tube 50 extends through the handle 46 and may terminate at the proximal end of the handle 46 in a telescope plug 57 suitable for receiving an imaging device such as a telescope. The plug 57 may be configured to hold a telescope within the inner lumen 70 such that the telescope can provide an image from the distal end 44 of the delivery tube 42. Beneficially, the plug 57 is positioned on the proximal handle 41 which is connected to the inner tube 50 and the outer tube 48. Thus, the telescope is fixed relative to the outer tube 48 and always moves with it, such that as the clinician operates the handle 46, the telescope also moves longitudinally relative to the inner tube 50. The plug 57 advantageously provides a reference against which the position of the expander 10 can be measured relative to the distal tip of the telescope and the outer sleeve 48.

[0086] The outer sleeve 48 is movable between a sheathed or stored position, in which the expander 10 is surrounded along its length by the outer sleeve 48, as shown in Figure 5, and a deployed or retracted position, in which the outer sleeve 48 moves proximally relative to the inner sleeve to uncover the expander 10 carried by the delivery tube 42. Additionally, the outer sleeve 48 is movable to and may be temporarily retained in an intermediate or partially deployed position in which the expander 10 is partially uncovered but retained on the inner tube 50, as described in more detail below.

[0087] The inner tube 50 includes a retention arrangement 52 for preventing longitudinal or angular movement of the expander 10 relative to the inner tube 50 when the expander 10 is held in a storage configuration within the delivery tube 42. The retention arrangement 52 is positioned at the proximal end 16 of the expander 10 in a longitudinal position such that the entire length of the expander 10 is held within the outer sleeve 48 at the distal end portion 44 of the delivery tube 42 when the outer sleeve 48 is in the stored configuration. The retention arrangement 52 holds the expander 10 in a fixed relationship relative to a distal lens of a telescope or other distal imaging device.

[0088] 5 illustrates an embodiment in which the distal end portion 44 of the inner tube 50 extends along the longitudinal length of the expander 10 such that the expander 10 is supported by the inner tube 50 along substantially its entire length. Supporting the expander 10 along its entire length is beneficial as the expander 10 advances along the urethra as it prevents the expander 10 from deforming and potentially becoming dislodged from the retention arrangement 52. However, in alternative embodiments, the distal tip 72 of the inner tube 50 may extend distally from the retention arrangement 52 only partway along the length of the expander 10.

[0089] 6, there is shown an underside perspective view of the distal end portion 44 of the inner tube 50, with the outer sleeve 50 and imaging device removed for clarity. The inner tube 50 is an elongated plastic tube including a distal end portion 44 opposed to a proximal end coupled to a handle 46. The inner tube 50 includes a hollow inner lumen 70 that may be used to receive an imaging device, such as a telescope or imaging tip with associated support and electronics.

[0090] 6-8, the inner tube 50 includes two sets of retention arrays 52. The retention arrays 52 are configured to prevent longitudinal or rotational movement of the expander 10 relative to the inner tube 50 and to prevent rotational movement of the expander 10 relative to the telescope. The retention arrays 52 are displaced onto the distal end portion 44 of the inner tube 50.

[0091] Typically, the retention array 52 is positioned on the inner tube 50 at a location proximal to the distal tip 72, a distance that exceeds the length of the expander 10. This is beneficial because when the expander 10 is in the stored position, the inner tube 50 may provide an orifice or opening for a telescope to visualize the anatomical structures, whether or not the expander is also visible, and can support the expander 10 along its entire length. This maintains the longitudinal struts 19 generally parallel to one another when in the stored position, thus facilitating smooth deployment of the expander 10 from the stored position to the expanded position.

[0092] Alternatively, when the inner tube 50 is shorter than the outer sleeve 48 such that the outer sleeve 48 overhangs the inner tube 50, the retention arrangement 52 may be positioned such that the distal end 13 of the expander 10 also overhangs the distal end of the inner tube 50. In this embodiment, the inner tube 50 provides support to only a portion of the expander 10. However, again, the support provided by the inner tube 50 is sufficient to maintain the longitudinal struts 19 generally parallel to one another when the expander 10 is in the storage configuration.

[0093] The retention arrangements 52 each include a distal projection 54 and a proximal projection 56 that define a retention slot 58 therebetween. The slots 58 are configured to receive the proximal apex 18 of the expander 10 to retain the expander 10 on the inner tube 50. When the expander 10 is positioned on the inner tube 50 in the compressed configuration, the proximal prongs 17 of the expander 10 wrap around and engage the distal projection 54 of the retention arrangement 52. This inhibits longitudinal movement of the expander 10 in the distal direction and also inhibits rotational movement of the expander 10 relative to the inner tube 50. The proximal apex 18 may also abut the proximal projection 56, thereby inhibiting longitudinal movement of the expander 10 in the proximal direction.

[0094] 7 is a longitudinal cross-sectional view of the retention array 52 with the expander 10 in a storage configuration and surrounded by the outer sleeve 48. The retention array 52 prevents longitudinal or rotational movement of the expander 10 relative to the inner tube 50. As shown in FIG. 7, the outer sleeve 48 of the delivery device 40 surrounds the expander 10, thereby preventing radial outward expansion of the expander 10 into a deployed position. FIG. 7 shows the outer sleeve 48 in a stored or partially deployed position with the expander 10 aligned with at least the retention array 52 and surrounded by the outer sleeve 48, thereby holding the expander 10 in a storage configuration on the inner tube 50.

[0095] The distal and proximal projections 54, 56 of the retention feature 52 are shown in detail in Figure 7. The projections 54, 56 each include angled walls 84, 86 such that the retention feature 52 has angled walls 84, 86 on distal and proximal sides of the retention feature 52.

[0096] The angled walls 84, 86 of the projections 54, 56 minimize the likelihood that the retention feature 52 will re-engage or snag on the expander 10 after the expander 10 has been deployed within the prostatic urethra 30. The angled walls 84, 86 are opposed about the retention slot 58 of the retention feature 52. Thus, if the inner tube 50 is moved longitudinally relative to the deployed expander 10 when the outer sleeve 48 is in the deployed position, the angled walls 84, 86 may contact the expander 10, but are unlikely to catch or snag on the expander 10. This is advantageous because catching or snagging the expander 10 after the expander 10 has been deployed can cause the expander 10 to move longitudinally within the anatomy, resulting in the expander 10 being mispositioned.

[0097] Additionally, the proximal and distal projections 56, 54 include generally vertical walls 80, 82 that define sides of the slot 58 such that the slot 58 has a U-shaped profile. The vertical walls 80, 82 of the projections 54, 56 advantageously act as guides to the radial expansion of the expander 10 when the expander 10 is being deployed. Specifically, the walls 80, 82 substantially radially limit the expanding movement of the expander 10 when the expander 10 is being deployed, thereby minimizing unintended longitudinal movement of the expander 10 relative to the inner tube 50 during deployment.

[0098] The slots 58 defined by the distal and proximal protrusions 54, 56 may be dimensioned to have a clearance fit with the wires of the expander 10. In another embodiment, the slots 58 may have an interference fit with the wires of the expander 10 such that the slots 58 exert a retaining force on the expander 10. However, the retaining force exerted by the slots 58 should be less than the radially outward self-expanding force of the expander 10 such that the expander 10 may still be deployed when the outer sleeve 48 is pulled back to the deployed position.

[0099] 7, a gap 88 is provided at annulus 85 between the upper or radially outer surface of projections 54, 56 and the inner surface of outer sleeve 48. The width of gap 88 is less than the diameter of the wire of expander 10 such that expander 10 is retained within slot 58 when outer sleeve 48 is in the retracted position. Expander 10 may contact the inner surface of outer sleeve 48 when expander 10 is retained in the retracted position by outer sleeve 48 and retention arrangement 52.

[0100] 8 is a cross-sectional view of the inner tube 50 and the retention arrays 52. As shown in FIG. 8, the inner tube 50 includes two retention arrays 52 for retaining the expander 10 on the inner tube 50. The retention arrays 52 are angularly spaced about 120° from each other such that the retention arrays 52 may engage two of the proximal prongs 17 of the expander 10. More generally, with reference to the circumference of the inner tube 50, the retention arrays 52 are at approximately the 4-5 o'clock and 7-8 o'clock positions, respectively.

[0101] It should be noted that in this example, the retention array is on the underside of the inner tube 50 and is in a substantially symmetrical position with respect to the central longitudinal plane of the inner tube 50, but the retention array 52 is not provided on the top of the inner tube 50. This would be the case if the anterior prostatic urethra were to press against the top surface of the inner tube 50 during deployment of the expander 10, in which case such pressure could prevent the expander 10 from dislodging from the retention feature 52 positioned on the top of the inner tube 50. However, this configuration of the retention array 52 is not required. If there are fewer concerns regarding reliable deployment, the retention feature could be positioned anywhere on the inner tube 50, including its top, e.g., three substantially equally spaced retention features are possible.

[0102] The skilled reader will understand that the retention arrangements 52 may be angularly spaced apart by any angle suitable for engaging and retaining an expander on the inner tube 50. Additionally, the skilled reader will understand that the inner tube 50 may include more or less than two retention arrangements 52 for engaging and retaining the expander 10.

[0103] The retention arrangement 52 is positioned at an angle on the inner tube 50 such that when the delivery tube 42 is inserted into the urethra with the handle 46 in an ergonomic, generally upright position, the expander 10 is already oriented to engage the prostatic lobes 11. This is beneficial because it allows the clinician to make only minor adjustments, if any, to the angular position of the expander 10 when positioning the expander 10 within the prostatic urethra 30.

[0104] 9 is a side view of the handle 46 of the delivery device 40. The handle 46 is connected to the proximal end of the delivery tube 42 such that the handle 46 can be held by a clinician and used to position the delivery tube 42. Additionally, the handle 46 is operable to control the position of the outer sleeve 48 relative to the inner tube 50 such that the outer sleeve 48 can be moved between a retracted position, a partially deployed position, and a fully deployed position, thereby allowing the clinician to deploy the expander 10 by operating the handle 46. The handle 46 is also operable to control the position of an imaging sheath relative to the inner tube 50 and the outer tube 48.

[0105] The handle 46 further comprises an irrigation duct 39 fluidly connected to the annulus 85 of the delivery tube 42. An irrigation reservoir may be coupled to the irrigation duct 39 so that fluid may circulate through the annulus 85 to clear the field of view of the imaging device 90 if debris or blood obscures or blocks the field of view of the imaging device. The irrigation duct 39 may also be connected to a vacuum (not shown) so that the annulus 85 may be used to drain fluid from the bladder 36 and / or urethra to a waste reservoir.

[0106] The handle 46 is designed to be operable by a clinician using one hand. Specifically, the handle 46 comprises a proximal grip 41 and a distal grip 43 that are longitudinally movable relative to one another. Moving the proximal grip 41 relative to the distal grip 43 moves the outer sleeve 48 and the telescope longitudinally relative to the inner tube 50. To this end, the proximal grip 41 may be connected to the inner tube 50 and the distal grip 43 may be connected to the outer sleeve 48 and the telescope through a plug 57. Moving the grips 41, 43 relative to one another thus affects the relative movement between the inner tube 50 and the outer sleeve 48 and the telescope plug 57.

[0107] In this example, the proximal grip 41 includes a thumb ring 45 on which the clinician can place his or her thumb, and the distal grip 43 includes a finger loop 47 on which the clinician can place his or her finger. The finger loop 47 allows the clinician to pull the distal grip 43 towards the proximal grip 41, thereby moving the outer sleeve 48 and telescope plug 57 proximally relative to the inner tube 50. This is beneficial because it ensures that the inner tube 50, and therefore the expander 50, remains stationary relative to the prostatic urethra 30 during deployment, allowing the telescope and outer sleeve 48 to move together. Also, advantageously, the clinician can see and be confident that the apex of the expander 10 is correctly positioned relative to the anatomy, and therefore the expander 10 can be deployed to the desired location within the anatomy.

[0108] Additionally, the clinician may operate the proximal and distal grips in reverse, for example, by pressing the fingers distal to the finger loop 47, opening the hand span, and then moving the distal grip 43 distally relative to the proximal grip 41. This is beneficial because it allows the clinician to return the outer sleeve 48 to the retracted position from a fully or partially deployed position.

[0109] The handle 46 further includes a safety catch or lever 49, which may be located, for example, on an upper surface of the distal grip 43, or on either side of the distal grip 43 or the power grip. The lever 49 is operable to prevent or allow longitudinal movement of the proximal grip 41 and the distal grip 43 relative to one another. The lever 49 may be movable between three distinct detent positions, for example, corresponding to a retracted position, a partially deployed position, and a fully deployed position of the outer sleeve 48.

[0110] For example, when the lever 49 is in the first, retracted position, the proximal grip 41 and the distal grip 43 are longitudinally locked relative to one another such that the outer sleeve 48 is held in the retracted position as shown in Figure 10. This is beneficial because the clinician may insert the delivery tube 42 through the penis and into the urethra without risking the outer sleeve 48 moving to the deployed position and deploying the expander 10 in the wrong position.

[0111] When the distal end region 44 of the delivery tube 42 has been advanced sufficiently along the urethra, for example to the bladder neck 32 or prostatic urethra 30, the clinician may move the lever 49 to the partially deployed position. This unlocks the proximal grip 41 and the distal grip 43, such that the clinician may pull the proximal grip 41 back relative to the distal grip 43 to move the grips 41, 43, and thus the outer sleeve 48 of the delivery tube 42, to the partially deployed position. At this stage, the movement of the proximal grip 41 is such that only about a 10-15 mm partial length of the expander 10 is uncovered relative to the delivery tube 42, to prevent the expander 10 from accidentally releasing and deploying.

[0112] 11 shows a schematic plan view of the distal end region 44 of the delivery tube 42 in a partially deployed position with the outer sleeve 48 retracted to partially desheath the expander 10. When in the partially deployed position, the distal end of the outer sleeve 48 is positioned distal to the retention array 52 but proximal to the distal end 13 of the expander 10. In this manner, the expander 10 is partially desheathed but still retained on the inner tube 50. From this position, if it is decided not to complete deployment of the expander 10, the clinician may operate the handle 46 to return the outer sleeve 48 to the retracted position.

[0113] By moving the outer sleeve 48 to the partially deployed position, the telescope 90 moves proximally such that the distal end 13 of the expander 10 is within the field of view 94 of the telescope 90. It will be apparent that imaging is performed from the inside out, i.e., from a perspective within the expander 10 looking at the anatomy through at least a distal portion of the expander 10. This effectively juxtaposes the expander 10 with the anatomy, thus providing a reliable reference for the clinician to see and understand the angular and longitudinal position of all portions of the expander 10 relative to the prostatic urethra 30.

[0114] Once the clinician is confident that the expander 10 is properly positioned within the prostatic urethra 30, the lever 49 is moved from the partially deployed position to the fully deployed position to allow the distal grip 43 to move longitudinally toward the proximal grip 41 to the fully deployed position. This causes the outer sleeve 48 and telescope 90 to move proximally relative to the inner tube 50, such that the expander 10 and retention array 52 are no longer completely covered by the outer sleeve 48, as shown in FIG. 12. Uncovering the retention array 52 allows the expander 10 to disengage from the retention array 52 and radially expand to the deployed position.

[0115] The three stages of deployment, i.e., retraction, partial deployment, and full deployment, beneficially allow the clinician to deploy the expander 10 in a controlled manner, mitigating the possibility of the expander 10 being accidentally or mistakenly deployed in the wrong place. For example, the lever 49 prevents accidental movement of the handle 46, which may cause the expander 10 to be incorrectly deployed. Additionally, the inner tube 50 may be held stationary relative to the anatomy during movement of the handle 46 as the telescope 90 moves within it, allowing the anatomy to be visualized along with the expander 10. This improves the accuracy of the deployment of the expander 10 and promotes radial expansion of the expander 10 with minimal longitudinal movement relative to the anatomy during deployment.

[0116] 13 shows an end-on view of the inner tube 50 and expander 10 in a storage configuration, with the outer sleeve 48 removed for clarity. The inner tube 50 includes an imaging device 90, such as a telescope or imaging chip, positioned within the lumen 70. The imaging device 90 shown includes an electronic imaging chip 92, such as a CMOS chip, and at least one light source 94 for illuminating the area being imaged by the imaging device 90. The light source 94 may be, for example, an LED or fiber optic configured to illuminate the area being imaged by the imaging device 90.

[0117] The imaging tip 92 has a wide field of view, e.g., 120° or more, allowing the clinician to view a wide area of ​​the anatomy. As shown in Figures 10-12, the field of view 94 of the imaging device 90 extends through the expander 10 when the outer sleeve 48 is in the stored configuration and the expander 10 is retained on the distal end 44 portion of the inner tube 50. This is advantageous because it allows the clinician to view the expander 10 relative to the anatomy which assists the clinician in angularly and longitudinally positioning the expander 10 within the prostatic urethra 30.

[0118] As shown in FIG. 10, when the outer sleeve 48 is in the retracted position, the field of view 94 of the imaging device 90 extends through the outer sleeve 48. However, in FIG. 11, when in the partially deployed position, the outer sleeve 48 is retracted such that it is no longer within the field of view 94 of the imaging device 90. Retracting the outer sleeve 48 from the field of view of the imaging device 90 in the partially deployed position is beneficial because it improves the range and clarity of the image provided to the clinician. Additionally, the partially deployed position allows the distal prongs 14 of the expander 10 to contact the lobes of the prostate 11 so that the clinician can see and fully understand the position of the expander 10 relative to the prostatic urethra 30 prior to full deployment. This advantageously allows the clinician to verify whether the expander 10 is correctly positioned prior to full deployment.

[0119] To illustrate this, Figure 14 is a schematic diagram of an image captured by imaging device 90 when outer sleeve 48 is in a partially deployed position. The image in Figure 14 shows that each of the distal prongs of expander 10 is aligned with and in contact with an outer prostatic lobe about the prostatic urethra 30. Specifically, the posterior prong 140 of the expander is shown surrounding or straddling the verumontanum 25, while the two anterior prongs 141, 142 of the expander 10 are oriented such that they engage an anterior lobe 145.

[0120] It will be appreciated that the images provided to the clinician by the imaging device 90 beneficially allow for simultaneous visualization of the longitudinal position of the expander 10 relative to anatomical structures, such as the verumontanum 25 and bladder neck 32, and also the angular position of the expander 10 relative to the bladder neck 25 and prostatic lobes. This facilitates accurate positioning of the expander 10 within the prostatic urethra 30.

[0121] 15, a flow chart is shown outlining a method of deploying the expander 10 within the prostatic urethra 30. In a first step 151, a clinician inserts the delivery tube 42 of the delivery device 40 through the penis and into the patient's urethra. The delivery tube 42 is inserted into the urethra in a stored configuration such that the expander 10 is covered by an outer sleeve 48.

[0122] The delivery tube 42 is advanced along the urethra until the distal end of the delivery tube 42 reaches the bladder neck 32. As the delivery tube 42 is advanced along the urethra, the clinician may view the patient's anatomical landmarks, such as the external sphincter 33, the verumontanum 25, and the bladder neck 32, from images captured by the imaging device 90. This is beneficial as it allows the clinician to assess the patient and check for structures that may impede the deployment of the expander 10, such as an obstructing intravesical midline lobe obstruction.

[0123] Next, at step 152, the clinician reconfigures the delivery device 40 from the storage configuration to the partially deployed configuration. To do so, the clinician moves the lever 49 from the stored position to the partially deployed position and then moves the distal grip 43 proximally to move the outer sleeve 48 proximally relative to the expander 10 and inner tube 50 so that the expander 10 is not partially covered. This allows the clinician to visualize the distal prongs of the expander 10 relative to the outer prostatic lobes around the prostatic urethra 30.

[0124] In step 153, the clinician positions the expander 10 at the target site in the prostatic urethra 30 by moving the distal end region 44 of the delivery tube 42 proximally from the bladder neck 32. As discussed with reference to FIG. 16 , the degree of proximal movement may be judged with the aid of scale marks on the delivery tube 42 to indicate the axial distance moved from the bladder neck 32. In this manner, the bladder neck 32 may be used as a reference for positioning the expander 10 longitudinally within the prostatic urethra 30.

[0125] When the clinician is satisfied that the distal end region 44, and therefore the expander 10, is in the correct longitudinal position, the clinician then rotates the delivery device 40 to orient the expander 10 at the appropriate angle within the target site. The expander 10 is oriented such that the distal apex 15 of the expander 10, as seen in the image captured by the imaging device 90, is aligned with the prostatic lobes around the prostatic urethra 30. The clinician may also move the delivery tube 42 further distally such that the verumontanum 25 is in the field of view 10 when the expander 10 is in the correct orientation. This allows the expander 10 to be placed in a clinically acceptable position between the bladder neck 32 and the bladder neck 25, with the apex circumferentially targeting the lateral lobes.

[0126] Once the clinician is confident that the expander 10 is correctly positioned within the prostatic urethra 30, the clinician may reconfigure the delivery device 40 to the fully deployed configuration in step 154. Alternatively, once the clinician is confident of the position of the expander 10, the clinician may return the delivery device 40 to the stored configuration and abort or retry the procedure.

[0127] The delivery device 40 is moved to the fully deployed configuration by first moving the lever 49 to the fully deployed position before moving the distal grip 43 proximally. This moves the outer sleeve 48 and telescope proximally while holding the inner tube 50, and therefore the expander 10, stationary relative to the target site. In a further embodiment, the inner tube 50 may be or comprise a camera lumen that moves proximally while holding the expander 10 stationary relative to the target site. This deploys the expander 10 to the desired location.

[0128] When the outer sleeve 48 is moved to the fully deployed position, the proximal apexes 18 disengage from the retention features 52 and expand radially outward. The walls 80, 82 of the slots 58 facilitate radial expansion of the expander 10 and minimize longitudinal movement of the expander 10 during deployment.

[0129] After the expander 10 has been deployed, the delivery device 40 may be returned to the stored or partially deployed configuration in step 155. This is beneficial because the outer sleeve 48 thus covers the retention array 52, reducing the risk of the retention array 52 inadvertently re-engaging and displacing the expander 10 after deployment. The clinician may then view the deployed expander 10 through the imaging device 90 to check that the expander 10 is correctly positioned. When the clinician is confident that the expander 10 has been correctly deployed, the delivery device 40 may be withdrawn proximally from the urethra.

[0130] Turning now to Figure 16, an embodiment of a delivery device 40 is shown in which the delivery tube 42 includes a series of graduation marks 160 spaced at known intervals along the length of the delivery tube 42, i.e., at a fixed position relative to the delivery tube 42 with the bladder neck 32, to allow for positioning of the expander 10. Figure 16 shows a schematic diagram of the inner tube 42 with an overmolded hub 164 attached to the proximal end of the inner tube 50. The hub 164 includes a boss hole 162 for attaching the hub 164 to the handle 46. The boss hole feature 162 ensures that the position of the inner tube 42 relative to the proximal grip 41 is maintained.

[0131] The graduation lines 160 are shown on the inner tube 50. However, the graduation lines 160 may be on the inner tube 50 or the outer sleeve 48. As the delivery tube 42 is advanced along the urethra, the graduation lines 160 are visible to the clinician, thereby providing the clinician an indication of the longitudinal position of the distal tip 72 of the inner tube 50 within the urethra.

[0132] The skilled reader will understand that the graduation lines 160 may be positioned at any known interval suitable for positioning the delivery tube 42 longitudinally within the urethra. Additionally, the graduation lines 160 may be numbered. The graduation lines may also be used to estimate the length of the prostatic urethra during treatment, which may guide the clinician to select the most clinically acceptable position for the expander 10.

[0133] The scale marks 160 may be used when the distal tip 72 of the inner tube 50 is positioned at the bladder neck 32 before moving the delivery tube 42 proximally. This is beneficial because the clinician may know, for example, that the expander 10 should be positioned two scale marks proximally from the bladder neck 32. In this case, when the proximal tip of the delivery tube 42 is positioned at the bladder neck 32, the clinician may then retract the delivery tube 42 by the two scale marks 160 to position the expander 10 at the desired longitudinal position. The clinician can read the scale marks along the portion of the delivery tube 42 that is in or out of the patient.

[0134] A delivery device 40 according to a further embodiment is described below with reference to Figures 17 to 26. For clarity, reference numbers of comparable features remain consistent across the two embodiments.

[0135] FIG. 17 shows a perspective view of a delivery device 40 according to a further embodiment. The delivery device 40 comprises a handle 46 operably connected to a flexible delivery tube 42. The delivery tube 42 is configured to at least partially receive the expander 10 in a compressed state and to position and deploy the expander 10 within the patient's prostatic urethra 30. The delivery tube 42 is similar to the previous embodiment in that it comprises an inner tube 50 surrounded by an outer sleeve 48 that is movable between a retracted position, a partially deployed position, and a fully deployed position. However, the delivery device shown in FIG. 17 further comprises an intermediate steering tube that surrounds the inner tube 50, which in turn is surrounded by the outer sleeve 48. The steering tube is not shown in FIG. 17, but will be described in more detail below.

[0136] 17 is beneficial because it allows the delivery tube 42 to bend and flex to conform to the path of the patient's urethra, thereby reducing discomfort experienced by the patient. The steering tube allows for the position and tilt of the distal tip region 44 to be controlled and steered, which beneficially aids in the insertion and positioning of the delivery tube 42 within the patient. Additionally, a steerable delivery tube 42 allows for the imaging device 90 of the delivery tube 42 to be moved to provide a wider field of view to the clinician.

[0137] FIG. 18 is a perspective view of the distal end region 44 of the delivery tube 42. For clarity, the distal end region 44 of the outer sleeve 48 is shown as transparent in FIG. 18. The distal end portion of the outer sleeve 48 is preferably of a rigid plastic material so as to accommodate the outward radial force exerted by the expander 10 and keep the expander 10 in a stored position within the system. Conversely, the proximal portion of the outer sleeve 48 is preferably of a flexible plastic material and may, for example, consist of or include a braided sheath. At least the proximal portion of the inner tube 50 is also of a flexible plastic and may consist of or include a braided sheath.

[0138] FIG. 18 illustrates a steering tube 170 that surrounds the inner tube 50 and is surrounded by the outer sleeve 48. The steering tube 170 is an elongated flexible plastic tube with a braided distal end 172. The steering tube 170 is operable by a clinician via the handle 46 to change the position and tilt of the distal tip region 44, and thus the expander 10. Additionally, in this embodiment, a retention feature 52 is secured to and extends distally from the braided distal end 172. The retention feature 52 is configured to engage the expander 10 and prevent longitudinal or circumferential movement of the expander 10 relative to the steering tube 170.

[0139] The distal end of the steering tube 170 is shown diagrammatically in FIG. 19 with the inner tube 50 and outer sleeve 48 removed for clarity. The steering tube 170 includes a steering ring 174 at the distal end 178 of the braided section 172. Two steering wires 176 are connected to opposite sides of the steering ring 174 and extend proximally along the length of the steering tube 170 to the handle 46. The steering wires 176 are operably coupled to the handle 46 such that a clinician may vary the tension in the steering wires 176. This allows the position and tilt of the steering ring 174, and therefore the expander 10, to be controlled by the clinician operating the handle 46.

[0140] The flexibility of the proximal portion of the outer sleeve 48 and the flexibility of the inner tube 50 are such that they can accommodate and allow for the deflection angle of the steering tube 170 without twisting or increasing the deflection force required by the steering wire 176.

[0141] The steering tube 170 further includes two retention arrays 52 for retaining the expander 10 within the delivery tube 42. The retention arrays 52 are elongated tabs that extend distally from a distal end 178 of the braided portion 172 such that the retention arrays 52 protrude from the end of the steering tube 170. The retention arrays 52 each include a retention slot 58 for retaining the expander 10 and are angularly spaced about the steering tube 170 such that the expander 10 is oriented in alignment with the prostatic lobes when the delivery tube 42 is inserted into the prostatic urethra 30.

[0142] 19 , the retention arrays 52 each include a proximal projection 56 and a distal projection 54 defining a retention slot 58 therebetween. The retention slots 58 are configured to at least partially receive the proximal end 16 of the expander 10, thereby inhibiting longitudinal or circumferential movement of the expander 10 relative to the inner tube 50. When the outer sleeve 48 surrounds the retention array 52, e.g., in the retracted or partially deployed configuration, the outer sleeve 48 surrounds the retention array 52 and prevents the expander 10 from expanding radially and thus the retention array 52 from becoming dislodged.

[0143] The inner tube 50 is longitudinally movable relative to the steering tube 170 between a distal position as shown in FIG. 18 and a proximal retracted position. When in the retracted position, the distal tip 72 of the inner tube 50 is positioned between the proximal end 16 and the distal end 13 of the expander 10. Moving the inner tube 50 between the distal and retracted positions beneficially changes the longitudinal position of the imaging tip 92 relative to the expander 10. Specifically, when the inner tube 50 is in the distal position, the imaging tip 92 is positioned distal to the distal end 13 of the expander 10 such that the expander is not within the field of view of the imaging tip 92. Conversely, when the inner tube 50 is in the retracted position, the distal end of the expander 10 is within the field of view of the imaging tip 92. This beneficially allows the distal end 13 of the expander 10 to be imaged relative to anatomical structures within the prostatic urethra 30.

[0144] 18, the inner tube 50 includes two grooves 95 extending longitudinally proximally from the distal tip 72 of the inner tube 50. The grooves 95 are configured to at least partially receive the retention arrangement 52. This is advantageous because the grooves 95 accommodate some of the thickness of the retention arrangement 52, thus reducing the overall diameter of the delivery tube 42. Additionally, the grooves 95 enable and guide movement of the inner tube 50 relative to the steering tube 170 between the distal and retracted positions.

[0145] 20 is a schematic diagram of one embodiment of the distal end region 44 of the delivery tube 42 in the stored configuration. When in the stored configuration, the inner tube 50 is in a distal position and the outer sleeve 48 is in a stored position surrounding the expander 10. The distal tip 72 of the inner tube 50 extends distally relative to the distal end of the outer sleeve 48 when the inner tube 50 is in the distal position. This beneficially allows the imaging tip 92 to capture images of anatomical structures that are not obscured by the expander 10 or the outer sleeve 48.

[0146] Additionally, the distal end portion of the inner tube 50 is of a hard plastic so as to support the expander 10 along its length when the inner tube 50 is in a distal position. As the delivery tube 42 is inserted into and along the urethra, the inner tube 50 thereby prevents the expander 10 from bowing inwardly which could otherwise cause the expander 10 to become prematurely dislodged from the retention array 52.

[0147] Turning now to FIG. 21 , the delivery tube 42 is now shown in a partially deployed configuration. In the partially deployed configuration, both the inner tube 50 and the outer sleeve 48 have moved proximally relative to the expander 10, and the distal end 13 of the expander is desheathed. Additionally, the inner tube 50 is in a stored position such that the distal tip 72 of the inner tube 50 is positioned at a longitudinal position between the proximal and distal ends of the expander 10. As shown in FIG. 21 , when the delivery tube 42 is in the partially deployed configuration, the distal end of the outer sleeve 48 is positioned proximal to the distal tip 72 of the inner tube 50 and distal to the retention array 52. ​​Thus, the outer sleeve 48 retains the expander 10 in a stored configuration without obscuring the field of view of the imaging tip 92.

[0148] 22 is a schematic diagram of the distal end region 44 of the delivery tube 42 in a fully deployed configuration. In the fully deployed configuration, the outer sleeve 48 is moved proximally to an extent that its distal end is positioned proximally against the retention feature 52. This completely uncovers the expander 10, allowing the expander 10 to expand radially, thereby disengaging from the retention array 52.

[0149] Turning now to FIG. 23, which shows a perspective view of the handle 46. The handle 46 includes three buttons 230a, 230b, 230c that are operable by a clinician to reconfigure the delivery tube 42 between a retracted configuration, a partially deployed configuration, and a fully deployed configuration, as outlined in FIGS. 20-22. The buttons 230a, 230b, 230c allow a clinician to easily adjust the delivery tube 42 between the various configurations. The handle 46 further includes a lever 234 connected to the steering wire 176. The lever 234 may be operated to vary the tension in the wire, thus controlling the position and tilt of the distal end of the steering tube 170.

[0150] The handle 46 may further comprise a lever or button that can lock the delivery tube 42 in a desired configuration to prevent a clinician from inadvertently reconfiguring the delivery tube 42 to a partially or fully deployed configuration before the expander 10 is properly positioned in the patient's anatomy.

[0151] The handle 46 of FIG. 23 further includes an irrigation tube 232, which is also shown in FIG.

[0152] FIG. 24 illustrates an alternative embodiment of a steering tube 170. In FIG. 24, the retention features 52 extend from a distal end 178 of the steering tube 170, such as to be connected to and extend distally from a steering ring 174. Each retention feature 52 includes a distal projection 54. In this example, a retention slot 58 is defined between the distal projection 54 and the distal end 178 of the braided portion 172 of the steering tube 170. The expander 10 may be at least partially received within the retention slot 58, as before.

[0153] FIGURE 25 illustrates a further embodiment of a steering tube 170. In FIGURE 25, the retention feature 52 extends from the distal end of the steering tube 170, as described above in connection with FIGURE 24. However, in this case, the retention feature 52 is attached to and extends from a retaining ring 250. The retention feature 52 and the retaining ring 250 can form a separate subassembly that can be coupled to the steering ring 174 of the steering tube 170.

[0154] 26, a flow chart is shown outlining a method of deploying the expandable implant 10 within the prostatic urethra 30. In a first step 251, the delivery tube 42 of the delivery device 40 is inserted into the patient's urethra via the penis. The delivery tube 42 is inserted into a stored configuration in which an outer sleeve 48 surrounds the expander 10, thereby holding the expander 10 in a stored configuration. The clinician may operate the handle 46 to control the steering ring 174 and adjust the angle of the distal tip region 44 of the delivery tube 42 to aid in insertion of the delivery tube 42 into and along the urethra.

[0155] The distal end of the delivery tube 42 is advanced along the urethra until it reaches the bladder neck 32. In step 252, the delivery tube 42 is reconfigured from the retracted configuration to a partially deployed configuration. In the partially deployed configuration, the inner tube 50 is retracted such that the imaging tip 92 at the distal end of the inner tube 50 can visualize the distal end 13 of the expander 10. In addition, the outer sleeve 48 is also retracted such that the distal end 13 of the expander 10 is desheathed, but the proximal end 16 of the expander 10 remains sheathed and retained on the retention layer 52.

[0156] In step 253, the clinician positions the expander 10 at the target site in the prostatic urethra 30 by moving the distal end region 44 of the delivery tube 42 proximally from the bladder neck 32 with the aid of graduation marks on the delivery tube 42 indicating the axial distance traveled from the bladder neck 32. The bladder neck 32 may thereby be used as a reference for longitudinally positioning the expander 10 within the prostatic urethra 30. When the clinician is confident that the distal end region 44, and thus the expander 10, is in the correct longitudinal position, the clinician then rotates the delivery device 40 to orient the expander 10 at the target site. The expander 10 is oriented such that the distal apex 15 of the expander 10, as seen in the image captured by the imaging device 90, is aligned with the prostatic lobes around the prostatic urethra 30.

[0157] As before, when the expander 10 is in the correct orientation, the clinician may move the delivery tube 42 further distally to expose the verumontanum 25, thereby placing the expander 10 in a clinically acceptable position between the bladder neck 32 and the bladder neck 25, with the apex circumferentially targeting the lateral lobe.

[0158] In step 254, when the clinician is confident of the position of the expander 10, the outer sleeve 48 is retracted to a fully deployed position so that the expander 10 is deployed within the prostatic urethra 30. Finally, in step 255, the delivery tube 42 is removed from the urethra. The delivery tube 42 may be withdrawn in the fully deployed configuration, or preferably, the clinician reconfigures the delivery tube 42 to a partially deployed or retracted configuration. In all configurations, but most effectively in the retracted configuration, the clinician may use the imaging tip 92 to visualize the deployed expander 10 and verify that the expander 10 has been properly deployed within the prostatic urethra 30.

[0159] It will be understood that various changes and modifications can be made to the present invention without departing from the scope of the present application. For example, the intermediate tube 170 to which the expander 10 is directly or indirectly fixed does not necessarily have to have a steering function.

[0160] Finally, turning to Figures 27-31, these figures show further details of practical embodiments of the present invention.

[0161] FIG. 27 shows three elongated elements of a delivery sheath forming part of the delivery system of the present invention. These three elongated elements of the delivery system are concentrically aligned sheaths: an innermost imaging sheath 200 with a rigid camera tip 202 illustrating the imaging head, an inner or intermediate steering sheath 204 surrounding the imaging sheath 200, and an outer sheath 206 surrounding the imaging sheath 200 and the steering sheath 204. In this example, all of the sheaths 200, 204, 206 are tubular, but in principle the imaging sheath 200 could be a solid but flexible rod with any wiring, cable or duct for the embedded camera tip 202, for example in the respective parallel channels of the extruded profile. In any case, such wires or cables must be isolated from each other and from any flow of irrigation liquid conveyed along the imaging sheath 200.

[0162] The sheaths 200, 204, 206 should be as thin as possible to ensure that the overall diameter of the delivery sheath assembly is advantageously small, e.g., in the described application, the outer diameter is less than 16 French (5.33 mm). As a non-limiting illustrative example, the outer sheath 206 may have a wall thickness of about 0.175 mm, while the main proximal section of the steering sheath 204 may have a wall thickness of about 0.71 mm, allowing about 0.61 mm for the expander 10 and clearance. The wall thickness of the imaging sheath 200 below the expander 10 may be, for example, about 0.195 mm.

[0163] The sheaths 200, 204, 206 are sufficiently flexible to accommodate the curvature of the male urethral anatomy and allow for deflection angles, e.g., 40-90 degrees, to access the prostatic urethra. In particular, the sheaths 200, 204, 206 must be able to bend along their length as they extend along the male urethra from the insertion point at the penile urethral meatus to the bladder neck. Thus, the sheaths 200, 204, 206 each have a flexible steering section to provide deflection actuated by a steering mechanism controlled by a handle (not shown) at the proximal end of the delivery sheath. The sheaths 200, 204, 206 also each have a flexible proximal section to provide deflection imposed by the anatomy, e.g., to track the curvature of the penile canal. For example, one or more of the sheaths 200, 204, 206 may be braided for flexibility to accommodate curvature of the anatomy and deflection of the imaging tip, but the construction must also be sufficiently stiff axially and circumferentially to resist the forces of insertion, steering, navigation, de-sheathing, and, if necessary, re-sheathing of the expander 10. As described below, any or all of the sheaths 200, 204, 206 may have stiffness and bending characteristics tailored for these purposes.

[0164] The torsional stiffness of the sheaths 200, 204, 206 must be sufficient to allow angular alignment of the expander 10 about the longitudinal axis. In this regard, the circumferential or angular positioning of the expander 10 is controlled by the overall rotation of the handle. Note that the handle thereby applies torque to the attached sheaths 200, 204, 206, but the sheaths 200, 204, 206 are fixed against circumferential angular motion relative to the handle and therefore cannot rotate independently of the handle.

[0165] Each sheath 200, 204, 206 has a hub 208 at its proximal end, although only those on the imaging sheath 200 and steering sheath 204 are shown here, which allow the sheath to be plugged into a specific axial location on the handle. The hubs 208 lock the respective sheaths 200, 204, 206 in the system in a manner that prevents them from moving in any direction other than axially along a fixed path of movement, as controlled by the clinician operating the handle.

[0166] The simplest and most basic form of sheath is a single extrusion comprising a polymeric material with a particular durometer value. However, single material extrusions with necessarily thin wall thicknesses can present technical challenges as they may twist or buckle when deflected by the steering mechanism, under axial compression, or under other bending loads. For this reason, any or all of the sheaths 200, 204, 206 may benefit from different material properties along their length to provide individual sheaths, and stacked sheath assemblies, with the necessary design characteristics to access the prostatic urethra, navigate the anatomy, and steer and support the expander 10.

[0167] Examples of characterization properties that may be tailored along the length of the sheaths 200, 204, 206 may include flexibility, kink resistance, trackability, the ability to apply an axial force parallel to the longitudinal axis, i.e., "pushability," and the ability to apply a torque about the longitudinal axis, i.e., "torqueability." Tailoring may be accomplished, for example, by the following options: Hybrid extrusion where two materials with different stiffness or durometer properties are joined by reflow or joint. A fully braided sheath is a custom multi-layer braided sheath with a specific pitch design or braid angle tailored for the required stiffness characteristics. The braid may be uniform along its length. A hybrid braided sheath is also a custom multi-layer braided sheath with a specific pitch design or braid angle tailored to the required stiffness characteristics. In this case, however, the braid varies along its length, for example with tighter and looser braids, or denser and less dense braids at different longitudinal locations where the sheath needs to be more or less flexible. The angle of the braid relative to the central longitudinal axis can also be varied to tune the flexibility along the length of the sheath. The hard tip mold section can be reflowed or overmolded onto the braided sheath.

[0168] FIG. 28 is a series of views showing the components of the distal end portion 210 of the delivery sheath of FIG. 27 as a stacked assembly, working radially outward from the inside to the outside in sequence.

[0169] Figure 28(a) shows a braided imaging sheath 200 with a rigid camera tip 202. The camera tip 202 has image sensing and illumination features as shown in Figure 13, in addition to an irrigation channel or duct that runs along the imaging sheath 202 and terminates at the distal tip. The irrigation duct may be fluidly connected to a Luer connector on the handle, allowing liquid to travel down the imaging sheath 200 from the proximal end.

[0170] FIG. 28(b) shows a steering sheath 204 that overlies the imaging sheath 200, surrounds the imaging sheath 200, and terminates at the proximal end of the distal end portion 210, thus being spaced away from the distal end and leaving a distal protruding portion of the imaging sheath 200 exposed.

[0171] FIG 28(c) shows a pull ring 212 added to the distal end of the steering sheath 204, and FIG 28(d) shows an implant holder 214 added to the distal end of the steering sheath 204 around the pull ring 212. The pull ring 212 and implant holder 214 are at the interface between the imaging sheath 200 and the steering sheath 204 and allow longitudinal movement of the imaging sheath 200 relative to the steering sheath 204. In particular, the imaging sheath 200 slides longitudinally within and relative to the steering sheath 204, the pull ring 212, and the implant holder 214.

[0172] The pull ring 212 and implant holder 214 will be described in more detail with reference to Figure 30. For now, it is noted that the proximal end portion of the implant holder 214 is radially oversized relative to the diameter of the steering sheath 204, thus defining a cylindrical bearing surface 216 that is raised against the steering sheath 204. It is also noted that the implant holder 214 has a stepped profile in the longitudinal direction such that its distal end portion is narrower than its proximal end portion, and a pair of lugs that function as the retention arrangement 52 define a radially projecting distal bearing surface 218 as previously described.

[0173] 28(e) shows an implant in the form of an expander 10 added to surround the exposed portion of the imaging sheath 200 that protrudes distally from the steering sheath 204. The wire thickness of the expander 10 is smaller than the graduated change in diameter of the implant holder 214 between the bearing surface 216 and the support surface 218. The expander 10 extends from a proximal end supported by the support surface 218 of the implant holder 214 to a distal end supported by the camera tip 202. The expander 10 is held against axial and circumferential movement relative to the steering sheath 204 by a retention array 52.

[0174] 28(f) now shows the outer sheath 206 added to surround all of the aforementioned components. The outer sheath 206 is now advanced distally to a retracted position where it holds and encases the expander 10 relative to the steering sheath 204 and the expander 10. Despite being thin-walled, the outer sheath 206 must constrain the crimped expander 10 without excessive deformation. Thus, optionally, the outer sheath 206 can have a relatively stiff section at its distal tip to constrain the crimped expander 10 adjacent to a relatively flexible proximal section that forms the majority of the length of the outer sheath 206.

[0175] It will be apparent that the longitudinal sliding movement of the outer sheath 206 relative to the steering sheath 204 is guided and facilitated by sliding on the bearing surface 216 of the implant holder 214. This minimizes the area of ​​sliding contact, and therefore friction, and maintains concentricity between the sheaths 200, 204, 206.

[0176] In this example, the distal end of the camera tip 202, with its image capture and illumination components, e.g., a CMOS chip and LEDs adjacent to the irrigation ducts, protrudes distally from the distal end of the outer sheath 206. This ensures the best possible field of view as the delivery sheath navigates the anatomy prior to deploying the expander 10. However, in other examples, the distal end of the camera tip 202 may be substantially flush with the distal end of the outer sheath 206 or even slightly recessed proximally.

[0177] The various views of FIG. 29 show the distal end portion 210 of the delivery sheath and illustrate the variations in the length of the rigid camera tip 202 parallel to the longitudinal axis of the delivery sheath.

[0178] Figures 29(a) and 29(b) show the short camera tip 202, as also shown in the view of Figure 28, in a retracted configuration and a partially deployed configuration, respectively. Correspondingly, the camera tip 202 is shown in advanced and retracted positions in Figures 29(a) and 29(b), respectively. In this example, the length of the camera tip 202 is approximately one-quarter of the overall length of the expander 10. A correspondingly long portion of the more flexible imaging sheath 200 is exposed beyond the distal end of the steering sheath 204 and lies beneath the expander 10.

[0179] 29(b) illustrates how, in a partially deployed configuration, the imaging sheath 200, including the outer sheath 206 and the camera tip 202, is retracted proximally relative to the steering sheath 204 and thus relative to the expander 10. Thus, beneficially, the image capture device of the camera tip 202 when in the retracted position can visualize the expander 10 against the background of adjacent anatomical structures from a vantage point within the expander 10.

[0180] 29(c) and 29(d) show a longer camera tip 202 than that shown in FIGS. 29(a) and 29(b), with both views of the distal end portion 210 in a retracted configuration in which the expander 10 is completely covered by the outer sleeve 206. In FIG. 29(c), the length of the camera tip 202 is approximately half the full length of the expander 10. A corresponding shorter portion of the imaging sheath 200 is exposed beyond the distal end of the steering sheath 204. In FIG. 29(d), the camera tip 202 extends substantially the full length of the expander 10. In that case, none of the imaging sheath 200 is exposed beyond the distal end of the steering sheath 204.

[0181] Thus, by varying the length of the camera tip 202 relative to the more flexible imaging sheath 200, the support underlying the expander 10 can be tuned to have different stiffness along its length. This can be useful, for example, to accommodate movement of the imaging sheath 200 through a deflected steering sheath 204, noting that the imaging sheath 200 must move within the deflected section of the steering sheath 204 that surrounds it, and therefore must be flexible enough to accommodate. Conversely, during resheathing, the distal end of the camera tip 202 must be pushed back to its starting position through the distal apex of the expander 10 in order to return to the distal tip of the delivery sheath. The camera tip 202 must be supported rigidly enough to undergo this distal movement without deflection or buckling of the structure supporting the camera tip 202.

[0182] Potentially, the stiffness of the imaging sheath 200 can be tailored to vary along its length, e.g., by tailored braiding with braided elements of varying density, pitch, angle, and / or thickness, to provide stable support for the expander 10, but make it easy to navigate around a deflected steering sheath 204.

[0183] The various views of Figure 30 show the assembly of the pull ring 212 and implant holder 214 in more detail. As best seen in Figures 30(a) and 30(b), a circumferential step 220 affects the aforementioned outer diameter change between the bearing surface 216 and the support surface 218 of the implant holder 214. Figure 30(a) shows that the height or radial projection of the retention array 52 is the same as or slightly less than the height of the step 220.

[0184] Each retention arrangement 52 is spaced distally from the step 220 to define a gap or slot 222 capable of accommodating a respective proximal apex of the expander 10 retained by the outer sleeve 206 (not shown) against the support surface 218. The step 220 thus functions as a proximal retention arrangement in cooperation with each retention arrangement 52.

[0185] Internally, as best seen in the longitudinal cross-section of Figures 30(c) and 30(d), the implant holder 214 has a circumferential shoulder 224 that affects a step change in diameter of its longitudinal lumen from a narrow distal portion 226 to a wider proximal portion 228. The inner diameter of the distal portion 226 is a snug fit with the outer diameter of the imaging sheath 200 (not shown).

[0186] The proximal portion 228 of the implant holder 214 receives the pull ring 212 as an interference fit. The pull ring 212 may also or alternatively be secured within the implant holder 214 by a bonding process suitable for the polymer, such as reflow or overmolding. An adhesive and hardener may also be used. The distal end of the pull ring 212 abuts the proximally facing shoulder 224. The proximal end of the pull ring 212 is distal to the proximal end of the implant holder 214. FIG. 30(d) shows that the narrowed distal end portion of the steering sheath 204 is received and secured within the pull ring 212. The inner diameter of the steering sheath 204 substantially matches the inner diameter of the distal portion 226 of the implant holder 214 and is therefore also a snug fit with the outer diameter of the imaging sheath 200.

[0187] As also shown in Figures 30(c) and 30(a), the pull ring 212 has a circumferential array of angularly spaced holes 230 to facilitate coupling of the steering ring to the implant holder through the coupling process, and two longitudinal slots 246 (only one of which is shown) positioned on diametrically opposite sides of the pull ring 212 (only one of which is shown) for securing steering wires (not shown).

[0188] Thus, this example has an implant holding and steering function that not only holds the expander 10, but also can steer the expander 10 and thus the sheath that supports it, in this example the innermost imaging sheath 200 with the camera tip 202. In this regard, it is advantageous to steer from behind the expander 10, i.e., at a position proximal to the expander 10, to guide the expander 10 forward through the anatomy to a deployed position.

[0189] Thus, in proximal continuity with the expander 10, the steering sheath 204 with attached pull ring 212 and implant holder 214 provides a retention feature to hold and orient the expander 10, a steering mechanism to act on a flexible steering section, and a flexible proximal section to track the penile canal. The construction of the steering sheath 204, in conjunction with the imaging sheath 200 and outer sheath 206, must provide sufficient tensile or axial strength to de-sheath and re-sheath the expander 10 and to allow for deflection of the expander. The construction of the steering sheath 204 must also provide sufficient torsional strength to angularly orient the expander 10.

[0190] In the example shown, the implant retaining feature is a molded component that houses a pull ring for steering and is a separate component, however, in alternative embodiments, the implant retaining feature and pull ring or other steering arrangement may instead be integrated into one component.

[0191] 31 illustrates, in some embodiments, how an interlocking mechanism can control the relative axial movement of the sheaths 200, 204, 206. In this example, that relative movement is permitted and controlled by a control element, such as, for example, a pin 248 that can move along a path defined in this example by the slot 236 as the slot 236 moves relative to the pin 248. The slot 236 can be defined, for example, by the distal grip 43 of the handle 46, to which the imaging sleeve 200 and outer sleeve 206 can be fixed, while the distal grip 43 can move, for example, relative to the steering sleeve 204 and the pin 248 fixed to the steering sleeve 204.

[0192] The slot 236 is shaped to interact with the pin 248 to define detent positions that prevent longitudinal movement of the pin 248 and limited detent ranges within which longitudinal movement of the pin 248 is limited. Movement of the pin 248 from the detent positions or between and beyond these ranges is possible only by deliberate relative angular movement between the pin 248 and the slot 236 about the longitudinal axis, for example, by articulating a toggle of the handle 46. More generally, the imaging and outer sheaths 200, 206 can only be moved by articulation of components of the handle 46, which allows them to move pre-calculated distances within and on the steering sheath 204, respectively, all in a concentric relationship.

[0193] In this example, the detent position is defined by a laterally offset notch 238 at one end of the slot 236. The detent range is defined by a first section 240 of the slot 236 in series with a second section 242 of the slot 236. The second section 242 is laterally offset from the first section 240 by a laterally extending twist or chicane 244 in the slot 236.

[0194] 31(a), the pin 248 is received in a notch 238 that prevents longitudinal movement of the pin 248 along the slot 236. This prevents the distal grip 43 from moving toward the proximal grip 45 of the handle 46, thus locking the outer sleeve 206 in its distally advanced, stored position securing the expander 10 from inadvertent deployment.

[0195] As shown in FIGURE 31(b), moving the pin 248 laterally out of the notch 238 allows the pin 248 to enter and move along the first section 240 of the slot 236, pulling the distal grip 43 towards the proximal grip 45 in a first stage of movement. The pin 248 can move longitudinally along the first section 240 to an extent limited by the chicane 244, as shown in FIGURE 31(c). In doing so, the outer sheath 206 and imaging sheath 200 move proximally a fixed axial distance towards the handle 46 into a partially deployed position.

[0196] The outer sheath 206 and the imaging sheath 200 move proximally together and the same longitudinal distance relative to the steering sheath 204, which remains fixed relative to longitudinal movement relative to the handle 46. As described above, this movement at least partially obscures the expander 10, allowing the expander 10 to be imaged from the inside out with the anatomy in view.

[0197] As shown in FIG. 31(d), moving the pin 248 laterally through the chicane 244 releases the pin 248 from the first section 240 of the slot 236, allowing the pin 248 to enter the second section 242 of the slot 240. The pin 248 can move along the second section 242, further pulling the distal grip 43 towards the proximal grip 45 in a second movement phase. As shown in FIG. 31(e), the longitudinal movement of the pin 248 along the second section 242 continues until the pin 248 encounters the opposite end of the second section 242. This phase has caused the outer sheath 206 to move proximally a fixed distance further to a fully deployed position where the expander 10 is not fully covered and is released from the system, thus being deployed.

[0198] Advantageously, resistance to lateral movement of the pin 248 must be overcome before the pin 248 can enter or exit the notch 238 and enter the first section 240 of the slot 236, or move in either direction across the chicane 244 between the first section 240 and second section 242 of the slot 236. This helps prevent inadvertent movement and provides tactile feedback to the clinician to verify the position of the pin 248 relative to various portions of the slot 236.

[0199] In another embodiment, the interlock mechanism may use rotational motion to drive or reciprocate linear motion of the sheath.

Claims

1. 1. A delivery device for deploying a self-expanding implant within a body cavity, comprising: at least one retention arrangement for retaining said implant against axial or circumferential movement; an elongated longitudinally extending outer element radially outward of the or each retention array; an imaging head disposed on a longitudinal axis extending radially inwardly of the or each holding array; a handle connected to a proximal end of the outer element, the or each holding arrangement being axially fixed relative to the handle and the outer element and the imaging head being axially movable relative to the handle; The outer element comprises: a storage position in which the outer element surrounds the implant and holds the implant engaged with the or each retention arrangement; the outer element is longitudinally movable bidirectionally relative to the handle between a partially deployed position in which the outer element does not cover a distal portion of the implant but surrounds a proximal portion of the implant and continues to retain the implant engaged with the or each retention arrangement; The imaging head includes: From a forward position when the outer element is in the stored position, The device is retractable proximally relative to the handle to a retracted position when the outer element is in the partially deployed position.

2. The device of claim 1 , wherein the imaging head is configured to define a field of view extending from a viewpoint radially inward with respect to the or each holding array.

3. The device of claim 2 , wherein the viewing point is disposed distal to the or each holding array.

4. The device of claim 2 or 3, wherein the field of view substantially excludes a distal end of the implant when the imaging head is in the advanced position.

5. The device of any one of claims 2 to 4, wherein the field of view of the imaging head substantially excludes a distal end of the outer element when the imaging head is in the advanced position.

6. The device of claim 2 or 3, wherein the field of view encompasses at least a distal end of the implant when the imaging head is in the retracted position.

7. 10. A device according to any one of the preceding claims, wherein the or each retention arrangement projects radially from a radially inner support surface of the outer element which is configured to support at least the proximal portion of the implant.

8. 8. The device of claim 7, further comprising an elongate longitudinally extending inner element defining the support surface and the or each retention arrangement.

9. 9. The device of claim 8, wherein the outer element is radially spaced from the inner element to define an annular portion between the outer element and the inner element, the annular portion including the at least one retention arrangement and providing a receiving portion for the implant.

10. 10. A device according to claim 8 or 9, wherein the or each retention array faces radially outwardly from the inner element.

11. The device of any one of claims 8 to 10, wherein the support surface extends to a distal end of the inner element that is distal to the imaging head when in the retracted position.

12. The device of any one of claims 8 to 11, wherein the imaging head is longitudinally movable relative to the inner element.

13. The device of claim 12 , wherein the imaging head moves with the outer element.

14. The device of claim 13 , wherein the imaging head moves with the outer element in a fixed relationship.

15. The device of any one of claims 8 to 14, wherein the longitudinal axis along which the imaging head lies extends within the inner element.

16. The device of claim 15 , wherein the imaging head is at a distal end of an elongate innermost element that extends longitudinally within and is longitudinally movable relative to the inner element.

17. The device of claim 16 , wherein the entire length of the innermost element extending proximally from the imaging head is flexible relative to the imaging head.

18. The device of claim 16 or 17, wherein the imaging head defines a secondary support surface configured to support at least the distal portion of the implant.

19. 20. The device of claim 18, wherein the auxiliary support surface of the imaging head is spaced from the support surface of the inner element by a portion of the innermost element.

20. A device according to any one of claims 8 to 19, wherein the inner element is configured to flex at a steering section proximal to the or each retention arrangement.

21. 10. A device according to any one of the preceding claims, wherein the outer element is longitudinally movable relative to the or each retention array to a fully deployed position in which the outer element does not cover the proximal portion of the implant sufficiently to disengage the implant from the retention array for radial self-expansion within the body cavity.

22. 22. The device of claim 21, further comprising a detent positioned to selectively control, disable, and enable the movement of the outer element to the fully deployed position.

23. 23. The device of claim 22, wherein the detents are also positioned to selectively control, disable, and enable the movement of the outer element from the stored position to the partially deployed position.

24. 24. The device of claim 22 or 23, wherein the detents are also capable of controlling, disabling and enabling movement of the imaging head.

25. 10. A device according to any one of the preceding claims, wherein the or each retention arrangement comprises proximal and distal projections defining a slot therebetween for at least partially receiving the implant.

26. 26. The device of claim 25, wherein the proximal projection extends circumferentially between two or more angularly spaced distal projections.

27. 11. A device according to any one of the preceding claims, wherein when the outer element is in the stored position and the partially deployed position, a gap is defined between a radially outer end of the or each retention array and a radially inner surface of the outer element, the gap being narrower than a radial thickness of a portion of the implant engaged by the retention array.

28. 10. A device according to any one of the preceding claims in combination with an implant engaged by the or each retention arrangement and at least partially covered by the outer element.

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