Device for the treatment of benign prostatic hyperplasia and associated lower urinary tract symptoms - Patent Application 20070122997

Abstract

Disclosed are devices and methods for managing and / or treating bodily tissue obstructing a hollow body lumen, including prostatic lobe tissue obstructing the urethra, for example, health conditions including benign prostatic hyperplasia (BPH), bladder outlet obstruction (BOO), benign prostatic obstruction (BPO), and related lower urinary tract symptoms (LUTS). A retrieval sheath having an elongate shaft member with at least one region of altered flexibility configured to compress the implant to a reduced profile for removal from the patient's body.

Description

Disclosure Contents

[0001] [Related Applications] This application claims priority to U.S. Provisional Application No. 62 / 943,112, filed December 3, 2019, the priority of which is expressly claimed and the disclosure of which is incorporated herein by reference in its entirety.

[0002] Field of the Disclosure SUMMARY The present disclosure relates to devices for managing or treating bodily tissue obstructing a hollow body lumen, such as prostate lobe tissue obstructing the urethra.

[0003] 〔background〕 The prostate is a walnut-shaped gland that surrounds the urethra, through which urine leaves the bladder, and plays a vital role in the male reproductive system. The gland starts small but tends to enlarge as men age. Excessive prostate enlargement results in a condition known as benign prostatic hyperplasia (BPH). Benign prostatic hyperplasia (BPH) refers to abnormal, non-malignant (non-cancerous) prostate growth that is very common in aging men. BPH is a chronic condition associated with the development of urinary outflow obstruction or luminal narrowing in the prostatic urethra. Bladder outlet obstruction (BOO) refers to a blockage at the base of the bladder that reduces or stops the flow of urine into the urethra and can occur secondary to BPH. A series of related conditions, collectively known as lower urinary tract symptoms (LUTS), can occur, including sexual dysfunction, frequent urination, difficulty urinating, urinary retention, urinary leakage, and urinary tract infections and bladder infections that worsen as the abnormal prostate growth enlarges and progresses.

[0004] Surgical procedures relieve BPH by removing significant portions of prostate tissue. Several conventional surgical procedures are available, all of which require hospitalization and some form of spinal, epidural, or general anesthesia. Transurethral resection of the prostate (TURP) is the primary surgical treatment for BPH and remains the gold standard against which other procedures are compared. Traditional surgical techniques vary in the location of the incision the surgeon makes to access the prostate and the method by which prostate tissue is removed. For example, some procedures use laser energy, heat, or radiofrequency to remove tissue from the prostate. These include laser enucleation, photoselective vaporization of the prostate (PVP), transurethral needle ablation with radiofrequency energy (TUNA), transurethral microwave thermotherapy (TUMT), and transurethral incision of the prostate (TUIP). However, these traditional surgical approaches to the treatment of BPH are invasive, irreversible, and have significant drawbacks, including the placement of temporary catheters for several months, risk of infection, loss of sexual function, urinary incontinence, and restenosis, where recurrent hyperplasia of cells in the prostate gland regrows and causes recurrent narrowing of the urethral opening, as well as the recurrence of the LUTS symptoms mentioned above.

[0005] While removing prostate tissue can relieve some BPH symptoms, tissue removal through traditional surgical approaches is irreversible, and any side effects of the surgery can cause lifelong suffering and affect a patient's quality of life. Additionally, surgical approaches are associated with inherent risks, including the risk of recurrence due to regrowth of the removed prostate tissue, and can require lengthy recovery periods of as long as 3-6 weeks, depending on the extent of disease and the specific surgical approach required for each individual patient.

[0006] Recognizing the shortcomings of traditional surgery, less invasive treatments have been developed and, depending on the extent of the disease, may be chosen by patients and physicians as an alternative to lifelong medication or surgery. These less invasive treatments may be suitable for patients who are unwilling or medically unfit to undergo surgical procedures performed under general anesthesia. Furthermore, younger patients may also desire less invasive, reversible treatments without impairing sexual function, leaving them open to permanent, irreversible procedures that affect sexual function later in life. Furthermore, because less invasive treatments allow for procedures to be performed in a doctor's office or clinic using local anesthesia, advantages include patient comfort and savings on the healthcare system compared to procedures under general anesthesia in a hospital setting.

[0007] Less invasive techniques include transurethral methods that actually remove enlarged prostate tissue, which are generally less traumatic than traditional surgery, but both are destructive and irreversible. To avoid destruction of prostate tissue, other treatment procedures designed to enlarge the diameter of the prostatic urethra without actually removing tissue from the prostate have been developed, such as by implanting a device designed to enlarge the urethra within the prostatic urethra. Prostate implants involve a urologist inserting a small device into the prostatic urethra, which has become narrowed by enlarged prostate tissue. Once in place, the implant expands and pushes out the tissue lobes, helping to keep the urethra open while protecting the enlarged prostate tissue from total impingement and opening of the urethra. Ideally, prostate implants would eliminate the need for surgical removal of prostate tissue and reduce the risks of infection, sexual dysfunction, and incontinence that are inherent and traditional to less invasive surgical approaches. The procedure can also be designed to be reversible, as the implant can be removed and additional surgical procedures can be performed in the future.

[0008] Thus, office-based treatment of BPH / LUTS using flexible cystoscopes, currently used to image the urinary tract, including the prostatic urethra, and diagnose BPH and related symptoms, involves placing an implantable expander device within the prostatic urethra to mechanically retract the lobes, enlarging the urethral lumen and allowing urine to pass. The expander can be retrievable using commercially available cystoscopes, sheaths and graspers, or other retrieval tools used in urological procedures. Therefore, it would be desirable to provide a sheath with features configured to aid in the retrieval of the implant from the prostatic urethra at any time after implantation for a given duration. The technology of the present disclosure meets these and other needs.

[0009] 〔overview〕 The present disclosure relates to a sheath for retrieving an implant from a deployment site within a body lumen. The present disclosure relates to a sheath for retrieving an implant from a deployment site within a body lumen. The sheath can include an elongate shaft member having at least one lumen with an inner diameter, an atraumatic distal end, and a proximal end. The shaft member has at least one region of altered flexibility. The distal end of the shaft member can be configured to compress the implant to a reduced profile.

[0010] In one aspect, a hub may be secured to the proximal end of the elongate shaft member, the opening in the hub tapering from a proximal diameter greater than the inner diameter of the shaft member configured to advance a cystoscope through at least one lumen of the shaft member.

[0011] In one aspect, the hub can have proximal and distal portions that thread together such that the proximal end of the shaft member is secured to the hub by compression. The proximal portion of the hub can have a frustoconical protrusion that engages with a flared portion of the proximal end of the shaft member.

[0012] In one aspect, the hub may be further configured to form a seal with a cystoscope inserted through the opening.

[0013] In one aspect, the hub may be further configured to releasably secure a cystoscope inserted through the opening.

[0014] In one aspect, the shaft member region having altered flexibility may be adjacent the distal end and may have a reduced durometer value compared to the proximal region of the shaft member. The shaft member region adjacent the distal end may have a different material than the proximal region of the shaft member.

[0015] In one aspect, the shaft member region adjacent the distal end with modified flexibility can be highly flexible relative to the proximal and distal regions of the shaft member to allow full articulation of the flexible cystoscope when introduced through a sheath. The shaft member region adjacent the distal end with modified flexibility can have a lower thickness or include features that enhance flexibility. For example, the proximal and distal ends can be reinforced with braided metal wire, and the region adjacent the distal end can be unreinforced with a metal braid or reinforced with a lower density braid (or a lower braid angle) to enhance flexibility. Other features include, but are not limited to, laser etching linear or spiral grooves in the shaft member region adjacent the distal end to enhance flexibility.

[0016] In one embodiment, the shaft member can have a reinforcement configured to facilitate compression of the implant. The reinforcement can be at least one metal band. The reinforcement can be very short, a few millimeters in length, typically 1-15 mm, or more preferably 2-5 mm.

[0017] In one aspect, the distal end of the shaft member can have a tapered edge. The tapered edge may be angled inward toward the inner diameter so that the sheath follows the contours of the cystoscope during advancement through the urethra or other body lumen without causing trauma, injury, or tissue damage and minimal pain to the patient during the procedure. The tapered edge of the sheath can be softer than the distal end to provide an atraumatic tip.

[0018] In one aspect, the distal end of the shaft member may be configured to seal with a cystoscope inserted through the shaft member.

[0019] In one embodiment, the sheath can have multiple lumens, where at least one lumen can be confined within another lumen or adjacent to another lumen.

[0020] In one embodiment, the shaft member has an inner diameter in the range of 1.7 mm to 6.7 mm (5F to 20F) and an outer diameter in the range of 2.7 mm to 8.7 mm (8F to 26F).

[0021] In one aspect, the implant may be a prostate implant having an expandable profile configured to restore patency to the patient's urethra.

[0022] The present disclosure also includes a method for retrieving or deploying an implant from or to a deployment site within a body lumen. A sheath may be provided, the sheath including at least one lumen having an inner diameter, an atraumatic distal end, and an elongated shaft member having a proximal end. The shaft member has at least one shaft member region of modified flexibility. A cystoscope may be introduced through the at least one lumen of the shaft member. The sheath and cystoscope may be advanced through the body lumen. The implant may be retrieved or released via relative movement with the sheath.

[0023] In one aspect, the implant can be secured against movement relative to the sheath, and the implant can be compressed to a reduced profile within the sheath, so that the sheath, cystoscope, and compressed implant can then be withdrawn from the body lumen.

[0024] In one aspect, the cystoscope may be releasably secured to the sheath prior to advancing the sheath and cystoscope through the body lumen.

[0025] In one aspect, compression of the implant can be confirmed by visualization.

[0026] In one aspect, the implant may be secured against movement relative to the sheath by a grasper.

[0027] The present disclosure also includes a sheath for introducing a cystoscope and a delivery catheter containing an implant for placement within a body lumen. The sheath can have an elongate shaft member having two or more lumens, each having an inner diameter, an atraumatic distal end, and a proximal end, a hub secured to the proximal end of the elongate shaft member, and two or more openings in the hub, each tapering from a larger proximal diameter, configured to advance a cystoscope through one lumen of the shaft member and a delivery catheter through another lumen of the shaft member.

[0028] The present disclosure also includes a method for placing an implant in a body lumen. The method may include providing a sheath including an elongate shaft member, a hub secured to the proximal end of the elongate shaft member, and at least two openings in the hub, each tapering from a larger proximal diameter. A cystoscope may be introduced through one opening and at least one lumen of the shaft member. A delivery catheter containing the implant may be advanced through another lumen of the shaft member until the delivery catheter is visualized. The cystoscope may be secured against relative movement with the sheath. The implant may be released at a target location within the body lumen. The sheath, cystoscope, and delivery system may be withdrawn from the body lumen.

[0029] Further features and advantages will become apparent from the following more particular description of preferred embodiments of the present disclosure, as illustrated in the accompanying drawings, in which like reference characters generally refer to the same parts or elements throughout the figures. [Brief explanation of the drawings]

[0030] [Figure 1] FIG. 1 is a cross-sectional view of the male anatomy, including the lower part of the bladder and the prostatic urethra, in a physiological configuration typical of a patient suffering from BPH, illustrating the placement of an implant that may be placed within the prostatic urethra using the devices and systems of the present disclosure, engaging prostatic tissue on both sides between the bladder neck opening and the verumontanum, according to one embodiment. [Figure 2] 1A and 1B schematically illustrate a side view of an implant retrieval sheath, according to one embodiment. [Figure 3] 1A and 1B schematically illustrate a cross-sectional view of an implant retrieval sheath, according to one embodiment. [Figure 4] 10A and 10B schematically illustrate a detailed view of the distal end of an implant retrieval sheath, according to one embodiment. [Figure 5] 10A-10C schematically illustrate a cross section of a multi-lumen embodiment of an implant retrieval sheath, according to one embodiment. [Figure 6]10A-10C schematically illustrate a cross section of an alternative multi-lumen embodiment of an implant retrieval sheath, according to one embodiment. [Figure 7] 10A and 10B schematically illustrate a sheath with a grasper advancing through a cystoscope to engage an implant, according to one embodiment.

[0031] Detailed Description It should be understood at the outset that this disclosure is not limited to the specifically exemplified materials, architectures, routines, methods, or structures, as such may vary. Thus, although several such options similar or equivalent to those described herein can be used in the practice or embodiments of this disclosure, the preferred materials and methods are described herein.

[0032] It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments of the present disclosure only, and is not intended to be limiting.

[0033] The detailed description set forth below in connection with the accompanying drawings is intended as a description of exemplary embodiments of the present disclosure and is not intended to represent the only exemplary embodiments in which the present disclosure may be practiced. The term "exemplary" as used throughout this description means "serving as an example, instance, or illustration" and should not necessarily be construed as preferred or advantageous over other exemplary embodiments. The detailed description includes specific details for the purpose of providing a thorough understanding of the exemplary embodiments of the specification. It will be apparent to those skilled in the art that the exemplary embodiments herein may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form to avoid obscuring the novelty of the exemplary embodiments presented herein.

[0034] For convenience and purposes of clarity only, directional terms such as top, bottom, left, right, upper, lower, over, above, below, below, rear, back, and front may be used with respect to the accompanying drawings. These and similar directional terms should not be construed as limiting the scope of the disclosure in any way.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. Furthermore, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise.

[0036] Definition: The terms "therapeutically effective displacement" or "therapeutically effective recession" or "therapeutically effective dilation" are used interchangeably herein and refer to the amount of prostate tissue displacement adjacent to a limited area of ​​the urethra sufficient to increase the urethral lumen and treat, improve, or prevent symptoms of benign prostatic hyperplasia (BPH) or comorbid diseases or conditions, including lower urinary tract symptoms (LUTS), bladder outlet obstruction (BOO), and benign prostatic obstruction (BPO), where the prostate tissue displacement exhibits a detectable therapeutic, preventive, or inhibitory effect. This effect can be detected, for example, by an improvement in clinical condition, or a reduction in symptoms or the absence of comorbidities. Examples of clinical measures include a decrease in the International Prostate Symptom Score (IPSS), a decrease in post-relief bladder residual urine (PVR) volume, or an increase in maximum urinary flow rate (Qmax), or an improvement in quality of life (QoL), and an improvement in sexual health (Men's Sexual Health Inventory or SHIM score, Men's Sexual Health Questionnaire or MSHQ score) after treatment. The exact distance or amount of prostate tissue displacement will depend on the subject's weight, size, and health; the nature and extent of the enlarged or diseased prostate condition; and the size of the implant selected for placement within the patient.

[0037] As used herein, a patient "in need of treatment for BPH" is one who would benefit from a reduction in the presence or resulting symptoms of enlarged prostate tissue caused by non-malignant hyperplasia of the prostate and related disorders, including LUTS, urinary outflow obstruction symptoms, and luminal stenosis of the prostatic urethra. As used herein, the term "implant" or "expander" or "device" refers to a prosthetic device that is implanted within the prostatic urethra to relieve LUTS associated with or caused by BPH.

[0038] As used herein, the term "tissue engagement," with respect to arms, struts, or other extensions of an implant's structure, refers to the length of the implant's physical structure that engages prostate tissue along the major portion of the lobe that compresses the urethra, limiting the tissue's ability to further affect urethral patency. "Tissue retraction" refers to the implant's ability to exert the necessary force to move tissue away from a compressed or constricted urethra. This necessary force can be provided by the implant's inherent structure or by the expansion of the implant from a compressed to an expanded configuration, particularly if the implant is fabricated from a shape-memory or superelastic material with a predetermined expanded configuration designed to engage enlarged prostate tissue and exert the necessary tissue retraction force. The length of the tissue-engaging or tissue-retracting structural feature that contacts within these definitions is away from the intralobular grooves that extend along the length of the prostate gland surrounding the urethra and requires contact with the length of tissue along the length of the two lateral lobes or the lateral and median lobes.

[0039] With regard to expressions relating to the orientation and anatomy of various structures described herein, the terms "proximal" and "distal" refer to the perspective of a medical professional, such as a urologist, manipulating the delivery system of the present disclosure to deploy the implants described herein. Thus, features of the delivery system held by the urologist's hand are at the "proximal" end, and the assembled system and implant, initially in a compressed configuration, are located at the "distal" end of the delivery system.

[0040] Referring to FIG. 1 , a cross-sectional view of the male anatomy shows the prostate gland 1 surrounding the urethra 2. The urethra 2 normally provides fluid communication from urine stored in the bladder 3 to be expelled from the body under the voluntary muscular control of the external urethral sphincter. Normal or “true” prostate tissue 4 surrounds the urethra 2 and, in the absence of disease, does not affect the patency of the urethra 2. In patients with benign prostatic hyperplasia (BPH), the urethra 2 is narrowed by hypertrophic tissue, i.e., prostate tissue 4, which exhibits excessive growth toward the urethra 2. This excess non-cancerous cell growth results in the symptoms of BPH described above, including lower urinary tract symptoms (LUTS), urinary outflow obstruction, and urinary incontinence. In FIG. 1 , an implant 5 delivered using the device and system of the present disclosure is shown engaging the prostate tissue 4 along its length to restore patency of the urethra 2 and ensure unimpeded urine flow from the bladder 3. As shown, selective placement of the implant 5 at the target site between the bladder neck opening 6 and the verumontanum 7 is an important feature to ensure that the implant 5 does not puncture, perforate, or dissect surrounding tissue. The implant 5 is designed to remain in the correct position within the prostatic urethra 2. The implant 5 does not extend into the bladder 3, where the structural material of the implant 5 could become encrusted or otherwise deteriorate from constant exposure to urine, potentially causing complications and making retrieval more difficult, and the implant 5 does not interfere with voluntary control of the external urethral sphincter or interfere with sexual function.

[0041] The implant 5 according to the disclosed technology has multiple tissue-engaging structures that exert force on the enlarged prostate tissue 4 adjacent to the urethra 2. As described below, the number of multiple tissue-engaging structures can be two, four, or more than four tissue-engaging extensions, such as struts or arms. The use of three extensions is avoided if the three extensions are oriented to fit within the intralobular grooves of the prostate 4. Therefore, any number of tissue-engaging structures is possible, as long as the structures are oriented asymmetrically to ensure that the implant 5 is oriented outside the three intralobular grooves formed by the length of tissue contact between the two lateral lobes and one median lobe. An embodiment using three tissue-engaging structures can be used to treat urethral anatomy when the anatomy consists of bilateral lobes and the third lobe is not involved in urethral stricture.

[0042] The implant 5 can be fabricated from shape-memory materials, alloys, spring materials, and superelastic materials, including nitinol (nickel-titanium alloy), nitinol-based alloys, cobalt-chromium alloys, spring steel, and spring stainless steels. Other known shape-memory materials include polyetheretherketone (PEEK), as well as shape-memory and bioabsorbable polymers and metals (polylactic acid, polyglycolic acid, and their copolymers; magnesium alloys). The above materials may be coated with thin-film coatings to prevent encrustation, corrosion, and stone formation. Coatings may include ceramic materials such as alumina, silicon carbide, silicon nitride, and zirconia, as well as other ceramic coatings that are inert to urine, prevent encrustation, stone formation, and prevent degradation of the implant-forming material in chemical or urinary environments. Coatings may also be polymers such as polytetrafluoroethylene (PTFE), parylene, silver and other antibacterial coatings, silicone derivatives, and other similar materials recognized by those skilled in the art.

[0043] The implant 5 may also include a therapeutic coating adhered to the surface of the implant 5 for the sustained release of drugs after implantation in the prostatic urethra 2 to reduce hypertrophy and tissue proliferation in a manner known as a drug-eluting implant. The coating contains pharmaceutically active anti-inflammatory and anti-proliferative agents, including sirolimus, novolimus, everolimus, biolimus, zotarolimus, paclitaxel, and others used to prevent restenosis.

[0044] The implant 5 can also be coated with drugs to treat BPH symptoms. Such embodiments have the advantage of using a high, localized tissue dose in the affected prostatic region of the urethra 2 to relax smooth muscle cells and reduce tissue proliferation and prostate gland 4 size without incurring side effects from drugs circulating in other parts of the body. Potential drug candidates include alpha-adrenergic blockers such as alfuzosin, doxazosin, tamsulosin, terazosin, and silodosin. Other drug candidates include 5-alpha-reductase inhibitors such as dutasteride and finasteride, and anticholinergics such as oxybutynin, fesoterodine, darifenacin, tolterodine tartrate, tolterodine, and solifenacin. Drug combinations, including alpha-blockers + 5-alpha-reductase inhibitors or alpha-blockers + anticholinergics, can also be coated on the surface. Additionally, anti-infectives or antibacterials or antibiotics such as fluoroquinolones (e.g., ciprofloxacin), macrolides, tetracyclines, and trimethoprim.

[0045] Typically, the drug is mixed with a solvent and polymer to form a solution, which is then spray-coated onto the outer surface of the implant 5 to achieve the desired drug-release characteristics. The manufacturing process is similar to that used for drug-eluting stents used to treat coronary artery disease. Often, the coating may be abluminal to ensure more effective drug release and deposition within the urethral tissue of the prostatic urethra 2 and minimize washout during urinary outflow. Alternatively, the drug may be deposited within microreservoirs or microdepots on the outer surface of the implant 5 for drug loading, and then coated with a polymer coating to controllably elute the drug within the urethral tissue. Typical polymers used for drug loading include polylactic acid (PLA), poly-L-lactic acid (PLLA), polyglycolic acid (PGA), and their copolymers; polyurethane; poly(methyl methacrylate) (PMMA) or poly(n-butyl methacrylate) (PBMA); and combinations thereof. Other polymers and solvents can be used by those skilled in the art to achieve sufficient drug loading and maintain coating integrity with the implant surface. Multiple layers of coating may be used to achieve the desired drug loading and sustained release characteristics.

[0046] An implant 5 for restoring patency of the urethra 2 can be removed after implantation by using a sheath 10, a grasper, and a cystoscope (not shown) in accordance with the techniques of the present disclosure, such as the retrieval sheath 10 shown in FIG. 2. In this exemplary embodiment, the sheath 10 includes an elongated tubular shaft member 12 having a hub 14 at a proximal end 16 and a distal end 18. During retrieval, relative movement between the sheath 10 and the implant 5 (not shown in this figure) compresses the implant 5 inside the sheath 10, allowing it to be removed from the patient. As will be appreciated, the relative movement can occur by distal movement of the sheath 10 while the implant 5 is held relatively stationary by the grasper, by proximal movement of the implant 5 being pulled by the grasper while the sheath 10 is held relatively stationary, or some combination of these movements.

[0047] To further aid in the description of this embodiment, FIG. 3 is a cross-sectional view showing details of the hub 14 and proximal shaft end 16. As shown, the hub 14 features a beveled opening 20 having a relatively large proximal diameter that tapers to a relatively small distal diameter corresponding to the inner diameter of the shaft member 12. As will be appreciated, the relatively large proximal diameter of the opening 20 facilitates the insertion of a cystoscope, which may be advanced through the lumen 22 of the shaft member 12. The hub 14 features a frustoconical proximal portion 24, which is engaged with a distal portion 26 by threads, which cooperatively compress the flared end of the proximal end 16 of the shaft 12 against the frustoconical proximal portion 24 to form a sealed connection. If desired, adhesives or other similar techniques can be further used to enhance the bond between the shaft 12 and the hub 14.

[0048] Additionally, FIG. 4 schematically illustrates a detailed view of the distal end 18 of the shaft 12. To facilitate retrieval of the implant 5, the distal end 18 is configured to have sufficient column strength to collapse the implant 5 while it is being retracted therein with a grasper. Additionally, the distal end 18 is configured to allow for maneuverability and / or articulation of the flexible cystoscope advanced through the lumen 22 while reducing or minimizing anatomical trauma. To enable this, the sheath 10 may be designed to include one, all, or a combination of the following features: The distal tip 18 may utilize a polymeric material of a different durometer than the main shaft 12. The distal end 18 may be reinforced with one or more metal rings 24 (those skilled in the art will appreciate that braids, coils, and other configurations may also be used to provide the desired reinforcement) to provide additional resistance to radial expansion and / or column strength, thereby assisting in the collapse of the implant 5 when retracted into the sheath 10. In such embodiments, the metal ring 24 may be made of a stronger, stiffer (high modulus) material, such as stainless steel, titanium, titanium alloys, cobalt-chromium alloys, or other biocompatible metals and alloys commonly used in medical devices. Additionally, the distal end 18 may feature a region 26 that is not supported by a metal reinforcement. The intermediate region 26 may be manufactured using a different (softer, lower modulus) material (such as a medical polymer or extrusion commonly used in medical devices) or a material with a lower durometer to have altered flexibility and exhibit greater flexibility compared to the distal end 18 and the proximal end 12. The region 26 may also have a lower wall thickness compared to the remainder of the sheath 10. It may also include other features that enhance flexibility, such as linear or spiral grooves, without compromising the structural integrity of the sheath. Such extreme flexibility in the region 26 does not significantly limit the range of articulation, maneuverability, or movement of the flexible cystoscope when inserted through the sheath 10. The softer region may be 1 to 50 mm in length, for example 2.5 to 7.5 mm.Furthermore, the distal end 18 may have a tip with a tapered edge 28, which provides a smoother transition between the cystoscope advanced through the inner lumen 22 and the outer diameter of the shaft member 12. The tapered edge 28 may be inwardly tapered so that the sheath tip does not bend outward and cause trauma and damage to tissue during advancement of the sheath, along with the cystoscope within the sheath 10, through a tortuous (or nonlinear) urethral lumen (or other body lumen). In addition, such a configuration minimizes pain when the sheath 10 and cystoscope are advanced through the prostatic urethra 2 under local anesthesia, facilitating procedures in a doctor's office or clinic without the need for general anesthesia. In other embodiments, the edge may also be rounded to prevent trauma or damage to tissue during advancement through the body lumen. Furthermore, the distal end 12 may be configured to seal over the cystoscope as it is advanced through the lumen 22. To accomplish this, at least a portion of the distal end 18 may be formed from the same material as the remainder of the shaft member 12, or, if desired, from a more resilient material, including, but not limited to, polyurethane, silicone, and the like.

[0049] An optional aspect of the hub 14 is that it includes silicone, rubber, or other elastomeric material 30 ( FIG. 3 ) to facilitate forming a seal between the cystoscope and sheath 10 as it advances through the lumen 22 to reduce backflow of bodily fluids. The seal may or may not require additional user input or steps to ensure a complete seal. In one embodiment, the seal is shaped and compacted so that insertion of the cystoscope automatically forms a seal between the sheath 10 and the cystoscope. In another embodiment, the hub 14 can be rotated, pushed, or otherwise interacted with to manually close the seal on the cystoscope. In such an embodiment, the seal also secures the position of the sheath 10 relative to the cystoscope during retrieval of the expander device. This facilitates advancement of the cystoscope and sheath 10 as a system (without relative slippage) during sheath 10 advancement, grasper advancement, and implant 5 gripping without affecting the maneuverability of the flexible cystoscope. Once the implant 5 is securely held, the hub 14 can be loosened to allow relative advancement of the shaft member 12 over the implant 5, collapsing the implant 5 into the lumen 22 of the shaft member 12. Once the implant 5 is inside the shaft member 12, the hub 14 can be re-tightened to securely attach the shaft member 12 to the inserted cystoscope. The system can be easily withdrawn without relative motion between the sheath 10 and the cystoscope and without damaging the cystoscope and the wall of the urethra 2.

[0050] The shaft member 12 and hub 14 have openings configured to allow insertion of a cystoscope or other endoscopic instrument to visualize anatomical features and assist in the procedure. The inner diameter of the shaft member 12 (shown schematically in FIG. 4) can range from 1.7 to 7.3 mm (5 to 22 Fr), or more preferably, from 2.7 to 6.0 mm (8 to 18 Fr), to allow passage of instruments with different diameters. The outer diameter of the shaft member 12 (also shown schematically in FIG. 4) is designed to be as small as possible to minimize trauma to the anatomical passageway, yet strong enough to allow advancement of instruments, and can range from 1.7 to 8.3 mm (5 to 25 Fr), or more preferably, from 3.0 to 7.0 mm (9 to 21 Fr). By way of non-limiting example, the sheath 10 can have an inner diameter of 6.7 mm (20 Fr) and an outer diameter of 8.0 mm (24 Fr). The overall length of the sheath 10 is sufficient to pass through the patient's urethra 2 and reach the location of the implant 5 within the prostate gland 4, and may be approximately 32 cm, for example. The overall length may range from 20 to 50 cm, depending on the patient's anatomy and the length of the different cystoscopes used during the procedure. Similarly, the hub 14 has an opening 20 to allow for the insertion of a cystoscope or other endoscopic instrument to visualize anatomical features and assist in the procedure. The inner diameter of the hub 14 may range from 1.7 to 7.3 mm (5 to 22 Fr), or more preferably, from 2.7 to 6.0 mm (8 to 18 Fr), to allow for the passage of instruments with different diameters. The outer diameter of the hub 14 is designed to be ergonomic for the user and may range from 2 to 50 mm, or more preferably, from 10 to 20 mm.

[0051] The shaft member 12 is desirably thin, flexible, and soft, yet strong enough to facilitate advancement without kinking. In one embodiment, the shaft member 12 is formed from a reinforced polymer extrusion. For example, the polymer extrusion can be made of materials such as PEBA (polyether block amide), polytetrafluoroethylene (PTFE), etc. The extrusion can also be multi-layered, using different polymers or the same polymer but with different hardnesses. The reinforcement material can be metal, such as stainless steel, nitinol, etc., or polymer, such as PEEK (polyether ether ketone), nylon, etc. The reinforcement material can be arranged in a coil or braid pattern and does not necessarily extend the entire length of the sheath 10. Alternatively, the shaft member 12 can be constructed solely from extruded polymer. The sheath 10 can also feature a liner 32 (FIG. 4) along the inner diameter to help facilitate advancement of the cystoscope or other instrument by reducing friction. The liner can be made of PTFE, nylon, or other materials with a low coefficient of friction. The sheath 10 can also be coated on its outer diameter with an additional lubricious or hydrophilic material to help facilitate advancement through the urinary tract. A suitable wall thickness for the sheath 10 is 0.0254-0.635 mm (0.001-0.025 inches), or more preferably 0.0762-0.381 mm (0.003-0.015 inches). As mentioned above, the hub 14 provides an angled opening 20 to facilitate the introduction of a cystoscope or other instrument, and also serves as a handle for the user to hold and manipulate the sheath 10 during retrieval of the implant 5. The hub 14 can be constructed from polycarbonate plastic or other suitable materials, including most thermoplastic polymers or metals.

[0052] In other embodiments, a sheath 10 according to the disclosed technology can employ a shaft 12 having multiple lumens. One example is shown schematically in cross section in FIG. 5, which depicts a shaft member 12 having two adjacent lumens 34 and 36. The inner diameters of the lumens 34 and 36 may have different inner diameters, as shown to accommodate a cystoscope and other ancillary devices, or may have the same diameter in alternative embodiments. Another example of a multi-lumen sheath 10 is shown schematically in FIG. 6, which depicts a shaft member 12 having a first lumen 38 and a second lumen 40 defined within the first lumen 38 by an inner tubular member 42. The shaft member 12 and the inner tubular member 42 can share a common portion of their respective circumferences, with the second lumen 40 being confined within the first lumen 38, which has a crescent-shaped configuration as shown. Alternatively, the inner tubular member 42 can be coaxially disposed within the shaft member 12, forming concentric lumens. As will be appreciated, in any of these alternative embodiments, the shape and size of the multiple lumens can be configured to optimize their respective internal dimensions within the constraints of the overall cross-sectional area of ​​the shaft member 12 and to tailor them to different cystoscope or other instrument profiles. The shaft member 12 may be fabricated from a multi-lumen extrusion having two or more lumens. Separate lumens allow for the advancement of cystoscopes, graspers, and other instruments, or irrigation through the lumens. Such embodiments are characterized by reduced outer diameters or profiles to minimize patient discomfort and trauma during device introduction and procedures.

[0053] As will be appreciated by those skilled in the art, the sheaths with multiple lumens described in Figures 5 and 6 also require different hubs with multiple lumens, sizes (lengths and diameters), and shapes to accommodate the introduction of different types of cystoscopes (disposable and / or reusable digital video cystoscopes and / or flexible and rigid fiberscopes) and other auxiliary devices or instruments (flexible and rigid graspers) during a medical procedure.

[0054] Furthermore, such a sheath 10 can be used not only for implant retrieval but also for implant placement using a cystoscope. For example, one of the lumens can be used to introduce a cystoscope, while another can be used to introduce a delivery catheter with the implant 5 for deployment at the target location. The length, number of lumens, and size of the lumens of the sheath 10 can be optimized for the specific instruments used in the medical procedure. Typically, the inner diameter of lumen 34 for introducing a 1.7 mm to 6.0 mm (5F to 18F) outer diameter cystoscope ranges from 2.0 mm to 6.7 mm (6F to 20F), and the inner diameter of lumen 36 for introducing a 1.7 mm to 4.0 mm (5F to 12F) outer diameter delivery catheter ranges from 2.0 mm to 4.7 mm (6F to 14F). Typical lengths of the sheath 10 range from 20 to 50 cm, depending on the type of cystoscope used during the medical procedure. Similarly, lumens 38 and 40 may be designed and optimized to introduce various medical instruments into a body lumen using the lowest profile sheath 10 to minimize trauma and damage. Different materials (varying in strength and modulus or durometer; braided wire reinforced or unreinforced) and dimensions (thickness) may also be selected for the proximal, central, and distal sections of sheath 10 and hub 14 to achieve desired properties. In some embodiments, hub 14 can incorporate irrigation ports for saline irrigation to facilitate imaging during medical procedures.

[0055] Subjects diagnosed with BPH / LUTS may be treated with an implant 5 to open luminal obstruction lobes within the prostatic urethra 2. The implant 5 is positioned between the bladder neck 6 and the verumontanum 7 for a predetermined period ranging from 30 days to several (1-5) years. Whenever desired, the implant 5 may be retrieved using a retrieval sheath in accordance with the techniques of the present disclosure. One exemplary routine involves inserting a flexible cystoscope into the sheath 10 through the angled opening 20 in the hub 14, ensuring that the sheath 10 does not interfere with the articulation of the flexible cystoscope. In particular, the flexible cystoscope may be advanced through the hub 14 and shaft member 12 of the sheath 10 until it exits the distal end 18. In one embodiment, the distal end of the cystoscope tip should extend approximately 2-5 cm beyond the tip at the distal end 18 of the sheath 10, ensuring maneuverability of the cystoscope. In embodiments featuring a hub 14 that seals or attaches to the cystoscope, appropriate manipulation can be performed to secure the cystoscope and sheath 10 together. The cystoscope and sheath 10 are then inserted as a system into the patient's urethra 2 to the location of the implant 5 (or other target device) until it is visible. As shown schematically in FIG. 7 , the grasper 8 is inserted through the working channel of the cystoscope 9 and manipulated to hold or secure the implant 5 in place. Once the implant 5 is firmly grasped, the retrieval sheath 10 is advanced forward (distally) over the cystoscope 9, gradually collapsing the implant 5 to a smaller profile at its distal end 18 as it is retracted into the sheath 10 under direct visualization of the cystoscope 9. As noted above, the grasper 8 can also be used to pull the implant 5 proximally within the sheath 10, such as by simultaneously retracting the grasper 8 and cystoscope 9, or a combination of these movements may be used to create the required relative movement. The implant 5 compresses or collapses to a lower profile as the sheath 10 is pushed or advanced over it. Visual confirmation that the implant 5 is sufficiently compressed within the sheath 10 can be obtained when the distal edge of the implant 5 is only just barely visible through the cystoscope 9.Once the implant 5 is inside the sheath 10, the retrieval sheath 10, cystoscope 9 and grasper 8 are simultaneously removed from the urinary tract.

[0056] Correspondingly, it will be appreciated from the above disclosure that sheaths from these techniques may be used at any time after placement of the implant 5, for example, immediately after implantation or after any given duration. As explained in further detail, the present disclosure describes a sheath 10 that meets several performance requirements, including any or all of the following characteristics: The sheath 10 may be atraumatic to the urethra 2 and surrounding anatomical structures within the body during advancement and retraction of the sheath 10 through the urinary system. The sheath 10 may facilitate retrieval of the implant 5 using a commercially available grasper 8, such as laparoscopic forceps, under direct visualization with a commercially available flexible cystoscope 9. The distal end of the sheath 10 may be sufficiently strong in terms of radial expansion and column strength to collapse the implant 5 to a smaller profile without kinking as the implant 5 is pulled within the sheath 10. The sheath 10 can hold the implant 5 in a constrained (low-profile or compressed to a small diameter), such as less than 6.0 mm (18F), configuration after the implant 5 is positioned within the sheath 10. The sheath 10 is configured to minimize pain or bleeding during use and minimize discomfort to the patient. The sheath 10 is configured to have a length sufficient to reach target sites, including the prostatic urethra 2 and bladder 3. The sheath 10 is configured to fit the length of all commercially available flexible cystoscopes, e.g., approximately 40-60 cm. The sheath 10 is configured to be soft and flexible enough to easily navigate the tortuous portion of the urethra 2 from the penis to the bladder 3. The sheath 10 is configured to be flexible enough not to significantly impede maneuverability of the cystoscope at its distal end, allowing visualization of anatomical features and landmarks (external sphincter, verumontanum, bladder neck, and bladder) during advancement and deployment. The sheath 10 may also be configured to secure / lock the sheath 10 onto the cystoscope 9 during advancement and after the implant 5 has been compressed within the sheath 10. The sheath 10 may also be configured to allow use by a single operator using a flexible cystoscope 9 and grasper 8 to retrieve the implant 5 without the need for an assistant.

[0057] Notably, no previously available device is configured for use in the above manner with a flexible cystoscope to retrieve a prostate implant. Existing sheaths with smaller diameters cannot accommodate a 5.7 mm (17F) cystoscope, while larger sheaths are stiff and can damage the urethra when advanced through the tortuous prostatic urethra, causing discomfort and pain to the patient. Furthermore, conventional sheaths typically have very stiff valves, which make inserting a scope through the sheath or advancing the sheath over the cystoscope extremely difficult, despite the use of medical-grade lubricants.

[0058] The exemplary embodiments disclosed above are intended merely to illustrate various utilities of the present disclosure. Numerous modifications, variations, and combinations of the functional elements and features of the present disclosure are possible in light of the above teachings, and it will therefore be understood that, within the scope of the appended claims, the present disclosure may be practiced other than as specifically disclosed, and the principles of the present disclosure may be readily extended, with appropriate modification, to other applications.

[0059] All patents and publications are incorporated herein by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference. While the present disclosure has been specifically disclosed in terms of preferred embodiments and optional features, it will be understood that modifications and variations of the concepts disclosed herein may be made by those skilled in the art, and that such modifications and variations are considered to be within the scope of the present disclosure.

[0060] [Embodiment] (1) A sheath for retrieving or deploying an implant from or to a deployment site within a body lumen, comprising: A sheath comprising an elongate shaft member having at least one lumen with an inner diameter, an atraumatic distal end, and a proximal end, the shaft member having at least one shaft member region of modified flexibility, the atraumatic distal end positioned opposite the proximal end, the atraumatic distal end configured to compress the implant to a reduced profile. (2) The sheath of embodiment 1, further comprising a hub secured to the proximal end of the elongated shaft member, and an opening in the hub tapering from a proximal diameter greater than the inner diameter of the shaft member, configured to advance a cystoscope through the at least one lumen of the shaft member. (3) A sheath as described in embodiment 2, wherein the hub includes a proximal portion having a frustoconical protrusion that engages with a flared portion of the proximal end of the shaft member, and a distal portion, which thread together so that the proximal end of the shaft member is fixed to the hub by compression. (4) A sheath as described in embodiment 2, wherein the hub is further configured to form a seal with a cystoscope inserted through the opening. (5) A sheath as described in embodiment 2, wherein the hub is further configured to releasably secure a cystoscope inserted through the opening.

[0061] (6) A sheath as described in embodiment 1, wherein the shaft member region with altered flexibility is adjacent the atraumatic distal end and has a reduced durometer value compared to the proximal region of the shaft member. (7) The sheath of embodiment 6, wherein the shaft member region adjacent the atraumatic distal end comprises a different material than the proximal region of the shaft member. (8) The sheath of embodiment 1, further comprising a reinforcing material configured to facilitate compression of the implant. (9) The sheath of embodiment 8, wherein the reinforcing material includes at least one metal strip. (10) A sheath as described in embodiment 1, wherein the atraumatic distal end of the shaft member has a tapered edge.

[0062] (11) A sheath as described in embodiment 1, wherein the atraumatic distal end of the shaft member is configured to seal with a cystoscope inserted through the shaft member. (12) A sheath as described in embodiment 1, wherein the sheath includes multiple lumens. (13) A sheath as described in embodiment 12, wherein at least one lumen is circumscribed within another lumen. (14) A sheath according to embodiment 12, wherein at least one lumen is adjacent to another lumen. (15) The sheath according to embodiment 1, wherein the shaft member has an inner diameter in the range of 1.7 mm to 6.7 mm (5F to 20F) and an outer diameter in the range of 2.7 mm to 8.7 mm (8F to 26F).

[0063] (16) The sheath of embodiment 1, wherein the implant is a prostate implant having an expandable profile configured to restore patency to the patient's urethra. (17) A method for retrieving an implant from or deploying said implant at a deployment site within a body lumen, comprising: providing a sheath including an elongate shaft member having at least one shaft member region of modified flexibility and an atraumatic distal end; introducing a cystoscope through at least one lumen of the shaft member; advancing the sheath and the cystoscope through the body lumen; and retrieving or releasing the implant via relative movement with the sheath. (18) The method of embodiment 17, wherein the step of retrieving the implant includes securing the implant against movement relative to the sheath, compressing the implant to a reduced profile within the sheath, and withdrawing the sheath, cystoscopy, and the compressed implant from the body lumen. (19) The method of embodiment 17, further comprising releasably securing the cystoscope to the sheath prior to advancing the sheath and the cystoscope through the body lumen. (20) The method of embodiment 18, further comprising confirming compression of the implant by visualization.

[0064] (21) The method of embodiment 18, wherein the implant is fixed against relative movement with the sheath by a grasper. (22) A sheath for introducing a cystoscope and a delivery catheter containing an implant for placement within a body lumen, comprising: an elongate shaft member having two or more lumens, each having an inner diameter, an atraumatic distal end, a proximal end, and at least one shaft member region having modified flexibility; a hub secured to the proximal end of the elongate shaft member; and two or more openings in the hub, each tapering from a larger proximal diameter, configured to advance a cystoscope through one lumen of the shaft member and a delivery catheter through another lumen of the shaft member. (23) The sheath of embodiment 22, wherein the hub is further configured to form a seal with the cystoscope inserted through the opening. (24) A method for placing an implant in a body lumen, comprising: providing a sheath including an elongate shaft member having at least one shaft member region of modified flexibility and an atraumatic distal end, a hub secured to a proximal end of the elongate shaft member, and at least two openings in the hub, each tapering from a larger proximal diameter; introducing a cystoscope through one opening and at least one lumen of the shaft member; advancing the delivery catheter through another lumen of the shaft member until the delivery catheter containing the implant is visualized; securing the cystoscope against relative movement with the sheath; Releasing the implant at a target location within the body lumen; and withdrawing the sheath, the cystoscope, and the delivery catheter from the body lumen.

Claims

1. 1. A sheath for retrieving or deploying an implant from or to a deployment site within a body lumen, comprising: an elongate shaft member having at least one lumen having an inner diameter configured for advancement of a cystoscope therethrough, an atraumatic distal end, and a proximal end, the elongate shaft member having at least one shaft member region having a different flexibility than the atraumatic distal end and the proximal end, the proximal end having a tubular portion, a flared portion, an inner surface, and an outer surface, the atraumatic distal end being positioned opposite the proximal end, the atraumatic distal end being configured to compress the implant to a reduced profile; a hub secured to the outer surface of the proximal end of the elongate shaft member, the hub having an opening tapering from a proximal diameter greater than the inner diameter of the elongate shaft member to a distal diameter corresponding to the inner diameter of the elongate shaft member, the hub comprising: i) a proximal portion having a cylindrical portion, a frusto-conical protrusion distal to the cylindrical portion, and a tapered portion proximal to the cylindrical portion, the tapered portion having an inner diameter defining the opening and an outer diameter increasing toward a proximal end of the proximal portion, the inner diameter of the cylindrical portion configured to correspond to the inner diameter of the elongate shaft member, and the frusto-conical protrusion configured to engage the flared portion of the proximal end of the elongate shaft member; ii) a distal portion, the distal end of the distal portion configured to engage the outer surface of the flared portion of the proximal end of the elongate shaft member and the proximal end of the distal portion configured to engage the outer surface of the tapered portion, the distal portion configured to thread onto the proximal portion to cooperatively compress and secure the flared portion of the proximal end of the elongate shaft member together to form a sealed connection; a hub including: Including the sheath.

2. The sheath of claim 1 , wherein the hub is further configured to include silicone, rubber, or other elastomeric material to facilitate forming a seal with the cystoscope inserted through the opening.

3. The sheath of claim 1 , wherein the hub is further configured to releasably secure the cystoscope inserted through the opening.

4. The sheath of claim 1 , wherein the shaft member region adjacent the atraumatic distal end has a reduced durometer value compared to a proximal region of the elongate shaft member.

5. The sheath of claim 4 , wherein the shaft member region adjacent the atraumatic distal end comprises a different material than the proximal region of the elongate shaft member.

6. The sheath of claim 1 , further comprising a stiffener configured to facilitate compression of the implant.

7. The sheath of claim 6 , wherein the stiffener comprises at least one metal band.

8. The sheath of claim 1 , wherein the atraumatic distal end of the elongate shaft member has a tapered edge.

9. The sheath of claim 1 , wherein the atraumatic distal end of the elongate shaft member is configured to seal with the cystoscope inserted therethrough.

10. The sheath of claim 1 , wherein the sheath comprises multiple lumens.

11. The sheath of claim 10 , wherein at least one lumen of the plurality of lumens is confined within another lumen.

12. The sheath of claim 10 , wherein at least one lumen of the plurality of lumens is adjacent to another lumen.

13. The sheath of claim 1, wherein the elongate shaft member has an inner diameter in the range of 1.7 mm to 6.7 mm (5F to 20F) and an outer diameter in the range of 2.7 mm to 8.7 mm (8F to 26F).

14. 10. The sheath of claim 1, wherein the implant is a prostate implant having an expandable profile configured to restore patency to the patient's urethra.

15. The sheath of claim 6 , wherein the shaft member region does not include the reinforcement material.

16. The sheath of claim 1 , wherein the shaft member region exhibits greater flexibility compared to the atraumatic distal end and the proximal end.

17. The sheath of claim 1 , wherein the shaft member region has a reduced wall thickness compared to adjacent regions.

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