US20060287570A1

US20060287570A1 - Endourethral device & method

Info

Publication number: US20060287570A1
Application number: US11/345,015
Authority: US
Inventors: Mark Whalen; Lloyd Willard; John Reid
Original assignee: AbbeyMoor Medical Inc
Current assignee: AbbeyMoor Medical Inc
Priority date: 2001-01-23
Filing date: 2006-02-01
Publication date: 2006-12-21
Also published as: WO2002058541A2; WO2002058541A3; US20020107540A1; US7108655B2; CA2435060C; US20060116547A1; JP2005504558A; EP1392388A4; JP2007244919A; EP1392388A2; ATE483492T1; WO2002058541A9; US7951064B2; CA2435060A1; CA2683264C; EP1392388B1; US8016742B2; JP4025648B2; CA2683264A1; US20060195008A1

Abstract

Embodiments of adjustable length intraurethral devices intended for patients with Lower Urinary Tract Symptoms (LUTS) are disclosed. These devices are to be placed within the human urethra and in communication with the bladder. Each device is easily adjustable to accommodate the prostatic length and sphincteric anatomy of the patient. Devices are stabilized in the urethra by two anchoring elements. The first anchor is fluid filled and positioned at the outlet of the bladder, and a second anchor is mechanical and is located at the bulbous urethra. These are separated by a structure which selectively supports a portion of the urethra from closing without restricting the portion of the urethra in the region of the external sphincter. These embodiments provide for the regulation of the flow of urine from the bladder by the natural control of the external sphincter when the user desires.

Description

This is a continuing application filed under 37 CFR §1.53(b) of a regular application Ser. No. 10/059,100, filed Jan. 23, 2002 under 35 U.S.C. §111(a) claiming priority under 35 U.S.C. §119(e)(1), of provisional application Ser. No. 60/263,202, having a filing date of Jan. 23, 2001; provisional application Ser. No. 60/295,535, having a filing date of Jun. 4, 2001; and, provisional application Ser. No. 60/329,859, having a filing date of Oct. 18, 2001, all of which were filed pursuant to 35 U.S.C. §111(b), each of which being incorporated herein by reference.

TECHNICAL FIELD

The present invention generally relates to medical devices, more particularly to endourethral devices, and still more particularly to endourethral devices having anchor structures which permit the discharge of urine therethrough and/or there around.

BACKGROUND OF THE INVENTION

Urinary problems can have serious consequences, particularly when the problem is one of retention, incomplete emptying, or dysuria. Urine flow problems include urine retention, incontinence, and difficult urination. Retention can result from any of a number of causes, including without limitation, spinal cord injury, typhoid, peritonitis, prostatic enlargement, urethral stricture, urethritis, cystitis, bladder tumors, or urethral calculus. Patients suffering from these and other conditions often require some interventional means to periodically drain or augment drainage of the bladder. Failure to do so can result in damage of the epithelium and detrusor muscles associated with the bladder, and an increased potential for bacterial invasion which is commonly thought to contribute to urinary tract infection potentially leading to life-threatening kidney failure.
Beyond notions of intervention, in roads are presently being made in the area of office and office/home based monitoring of patients for purpose of diagnosing the contribution of the prostatic urethra to the outflow urodynamics. Differential diagnosis is understood by accepting that there are three primary anatomical organs which interact to contribute to the function of urination. First the bladder, second the urethra, and third the sphincter(s). The prostatic gland surrounds the urethra in the very short segment between the bladder, at its outlet, and the external sphincter. When the patient experiences symptoms of bother which may be made manifest in several independent or co-existing difficulties during urination, treatment is often sought.
For example, bothersome symptoms might include: (i) incomplete emptying, (i.e., the patient is only able to urinate small volumes, e.g. <100 milliliters (ml), or has an elevated volume of urine left in the bladder following urination, e.g. >100 ml. per attempt); (ii) frequent urges to urinate (i.e., experiencing a frequent feeling of needing to urinate by an individual); (iii) intermittency (e.g. a patient's flow stops and starts often during urination); (iv) has a very weak and inconsistent urine flow stream; (v) stress incontinence (e.g. leaking during lifting or straining as a result of excessive urine in the bladder or weakened sphincters. With the exception of stress incontinence, each of these may contribute to nocturia (i.e., poor sleep due to the repeated need to urinate during the night), yet a further symptom.
Up to two million office visits annually in the United States are attributed to patients being bothered by some form of lower urinary tract symptoms (LUTS). As previously noted, there are two primary organs, and the prostate, involved with the event of urination. The symptoms are virtually always suspected to be caused by the intrusion of an enlarged prostate gland upon the urethra, however, symptoms are often caused by irregularities in bladder function, or sphincter deficiencies. For this reason, bladder outlet obstructions (BOO) is a major subgroup of LUTS. In men between the ages of 55 and 75 years, it is estimated that between 50 and 75% have some degree of bladder outlet obstruction, however, it may not be responsible for their symptoms.
Bladder outlet obstructions are primarily caused by the enlargement of the prostate gland (e.g., benign prostate hyperplasia (BHP)) which results in radial compression of the urethra surrounded thereby (i.e., the prostatic urethra), thus obstructing (i.e., constricting) urine flow, resulting in incomplete emptying of the bladder (i.e., there being what is clinically referred to as a “post void residual” (PVR) remaining in the bladder). Heretofore, males presenting with LUTS have few diagnostic options prior to either long term pharmacological, or invasive irreversible medical procedures such as trans urethral resection of the prostate (TURP), or non-surgical procedures such as thermal treatment of the prostate.
It is well known within the urological community that significant numbers of men undergoing treatment for prostate disease have sub-optimal results. According to Bruskewitz, BPH can be discussed in terms of prostatic enlargement, outlet obstruction and LUTS. Jepsen J. V. and Bruskewitz R. C., Comprehensive Patient Evaluation for Benign Prostatic Hyperplasia, 1998, Urology 51 (A4):13-18. In addition to the usual factors believed to lead to prostate induced LUTS (e.g., enlarged prostate and increased prostate muscle tone) other conditions of the lower urinary tract impact male voiding and need to be considered. Bruskewitz stated that a large part of the symptomotology of BPH might be explained by bladder dysfunction.
Bladder conditions that are prevalent in men with LUTS, either separately or in combination with outlet obstruction, include detrusor instability and detrusor hypocontractility. Kaplan S. A. and, Te A. E., Uroflowmetry and Urodynamics, 1995, Urologic Clinics of North America 22 (2):309-320. In a population of 787 men with symptoms of prostatism, Kaplan found that 504 (64%) had demonstrable prostatic urethral obstruction, of which 318 had concomitant detrusor instability. In the group, 181 had detrusor instability as their sole diagnosis. Impaired detrusor contractility was present in 134 (17%) and 49 of these had impaired detrusor contractility as their only diagnosis. Bruskewitz and others have also shown that a significant number of men with LUTS, including those who receive definitive treatment, are unobstructed. Abrams P., In Support of Pressure Flow Studies for Evaluating Men with Lower Urinary Tract Symptoms, 1994, Urology 44 (2): 153-55. Patient satisfaction rates after definitive prostate treatment vary from 100% to 75% or less. In some cases the lack of success may be related to unidentified bladder dysfunction. Bruskewitz concluded that bladder dysfunction should receive more attention (in the evaluation and treatment of LUTS) and better measures should be developed to quantify it. Presently, urodynamic methods to assess bladder outlet obstruction generally include uroflow testing, pressure flow testing and general patient history/examination.
Uroflow testing provides information about the combined contribution of the detrusor and urethra to uroflow. The limitation of uroflow testing is that it is not possible to determine with certainty in all cases whether a low flow and a poor voiding pattern are secondary to outlet obstruction, detrusor hypocontractility or a combination thereof. Further, the test can be problematic because it is only a single event that can be influenced by patient factors such as anxiety and performance of the test (i.e. direction of the urine steam into the collecting reservoir). Abrams found that the success rate was only 70% when uroflow was used to select patients for surgery. Abrams P. H., Prostatism and Prostatectomy: The Value of Flow Rate Measurement in the Preoperative Assessment for Operation. J. Urol 1977, 177:70-71.
Pressure flow testing can be used to define outlet obstruction and, in addition, provides information about the contractility and performance of the bladder. The pressure flow test, however, is not much more successful in predicting success of treatment, as defined by the patient, than uroflow (75% v 64%). Jepsen J. V. and Bruskewitz R. C., Comprehensive Patient Evaluation for Benign Prostatic Hyperplasia, 1998, Urology 51 (A4):13-18. Therefore the urological community as well as the Agency for Healthcare Policy & Research (AHCPR) do not find justification for its routine use.
Finally, the standard work-up of patients with LUTS being evaluated for bladder outlet obstruction generally consists of history and physical examination, including assessment of prostate volume, PSA, uroflow testing, quality of life, and symptom and bother index. Based on the results, treatment decision are made. Using these evaluations underlying problems with bladder function cannot be detected.
In lieu of traditional urodynamic test methodologies such as the use of video urodynamics simultaneously with the holding and release of urine, cystometry, urethral pressure profiling, ultrasonic volume assessments (i.e., PVR), and uroflowmetry, each of which address the filing/emptying conditions (i.e., dynamics) of the bladder, endourethral devices and accompanying methodologies have been developed specifically to ascertain the nature of the BOO. For instance by permitting the structures of the lower urinary tract to physiologically act in a sequential and incremental manner upon portions of a device during a natural micturition event, an observable change in fluid dynamics in furtherance of lower urinary tract symptoms diagnosis may be noted.
Devices have been developed to be positioned in the urethra and/or bladder to correct the problems of urine flow. Problems and disadvantages of heretofore known devices include the deleterious effects (i.e., pitting, depositions, etc.) associated with the urethral environment upon critical device components (e.g., valve actuators, flow conduits, etc.) which at a minimum render such devices less effective, and which at a maximum, cause device component failure or render the device wholly ineffective, which necessitates emergent removal and, as the case may be, urinary tract damage repair. Problems of device leakage, or less than complete emptying of the bladder are also widely known. Furthermore, issues surrounding device deployment and fit, positioning, repositioning, and retention (i.e., sufficient anchoring) have also been well documented.
It is especially critical that the endourethral device be stable with respect to position (i.e., a physiologically properly deployed and stable position), and comfortable to wear, as the urinary tract is sensitive to contact. Inter-urethral stents have been utilized within the male urethra within the prostatic region with many users foregoing such devices for alternate therapies due to feelings of discomfort and/or pain. Many endourethral devices have similarly been evaluated for urinary incontinence for females. Based upon clinical findings, many have been shown to be uncomfortable, thus severely retarding their utility as a therapy. Other devices have migrated into the bladder, or have been expelled under straining conditions.
Furthermore, it is imperative that the device be no more invasive as is necessary. For instance, it is advantageous that the device minimally engage the structures of the lower urinary tract, particularly in accomplishing an anchoring function. For example, it is well known that secretions of the prostatic urethra, including the Cooper's gland, whether during sexual function or otherwise, is clinically beneficial, the secretions are comprised, in part, of antimicrobial agents which assist in the prevention of urinary tract infections. It is further believed that bathing of the bladder neck with urine assists infection prevention. Generally, flow of urine external of an endourethral device permits the free passage of urinary tract fluids from the urethra as urine is released, thereby allowing a more physiologically normal urine discharge. Thus, whether it be a short or long term endourethral device, for interventional, diagnostic or other purpose, stable anchoring in combination with physiologically proper, non-traumatic device deployment and retention is essential.

SUMMARY OF THE INVENTION

The adjustable urethral device of the subject application, in all its embodiments, enables a clinician to reduce inventory requirements, and allows for precise fitting to the patient's needs. Urologists are increasingly finding great utility in fitting the patient accurately. This precise fitting will enhance the value of the use of lower urinary tract flow control apparatus. While adjustments have been described in several specific manners, it may be easily appreciated by those skilled in the art that adjusting either the threads which “span” the proximal element and the tube, or the length of the proximal tubes, adjustments may be accomplished which enhance the utility and methodology of the use of the device. Further, it may be appreciated that a fixed length proximal tube which passes through at least 40% of the prostatic urethra coupled with adjustable threads cooperatively will provide for a suitable device in many patients. It may be further appreciated that when incorporating the previous applications, that a variable length flow around device may be easily accomplished when the proximal support structure which is analogous in anatomical location during use with the tubes may be enabled by either allowing it to telescope, or changing the thread lengths.
Accordingly, it is an objective of the invention to provide additional device and procedural options for the care and diagnosis of patients who present to the urologist with lower urinary tract symptoms (LUTS).
For each user, there are two inter-dependent parameters which may be easily measured in order to gain an increased understanding of the patients urodynamic status. First, the post void residual (PVR). Increased PVR will occur when there is either hyperplasia (i.e., thickening) of the prostatic gland, or a bladder that is not functioning properly due to decompensation of the muscular function. Secondly, the flow rate of urine during emptying of the bladder is a strong indicator of the function of the bladder when obstruction due to the prostate is not present.
The device of all embodiments provides and allows patients to empty their bladders in a natural way and will assist in the reduction of PVR in patients with obstructed urethras due to an enlarged prostate if the prostate is the sole factor, as it often is. All embodiments provide relatively unrestricted passage of urine from the bladder to that location. Simple placement of these devices allows for a urologist to easily determine whether prostatic hyperplasia is the cause of the LUTS.
Each of the devices and methods of use are for individuals with sufficient bladder contractility, and offer a high probability of reducing PVR. Reducing the PVR will in many instances further result in relief from sleep deprivation and reduce the risk of full retention. This diagnostic utility is provided when the user has experience with an unobstructed prostatic urethra. The change in his symptoms will assist greatly in confirming whether an enlarged prostate is the cause of his symptoms. If the symptoms persist after the prostatic urethra is supported open, it is unlikely that he will benefit from a trans-urethral resection procedure (TURP), or alternative therapies. In this situation the source of his problems may be bladder or sphincter related.
The devices of these embodiments are easily placed into the patient without the necessity for external visualization such as rectal or abdominal ultrasound. Though these visualization methods are available to the urologist or physician, it is undesirable to use them because of cost and/or discomfort to the patient. The devices of all the embodiments may be installed in similar fashion to a Foley catheter by simply inserting the device, inflating the proximal anchor, withdrawing the device into the bladder outlet, and removing the insertion device. This provides further utility for a patient who is has excessive symptoms of being obstructed, or is in danger of going into a state of urinary retention due to use of drugs such as antihistamines, or having had a recent surgery.
Finally, the following U.S. patents, printed publications or provisional applications are noted, and incorporated herein by reference: 60/168,306 (see U.S. Pat. No. 6,551,304); 60/179,038 (see U.S. Pat. Nos. 6,527,702, 7,001,327); 60/223,345 (see US 2003/0208183 A1); 60/229,143 (see U.S. Pat. No. 6,719,709); 60/259,809; 60/263,202 (see US 2002/0107540); 60/264,700 (see U.S. Pat. No. 6,719,709); 60/265,535 (see US 2002/0107540); and, 60/299,973 (see US 2002/0198506 A1).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically depicts the human male urinary bladder and urinary passage;
FIG. 2 illustrates an endourethral device of the subject invention, particularly showing “flow by” proximal and distal anchor systems;
FIG. 2A is a section view of the device of FIG. 2 taken about line 2A-2A, more particularly, a sectional view of the proximal anchor of same;
FIG. 3 is a longitudinal cross section of an alternate embodiment of the device of the subject invention, the anchor elements in extension;
FIG. 3A is a section view of the device of FIG. 3 taken about line 3A-3A, more particularly, a sectional view of the distal anchor of same;
FIG. 4 is a view of the device of FIG. 3, the anchor elements in retraction;
FIG. 5 illustrates an alternate embodiment of the endourethral device of the subject invention, particularly illustrating a distal mechanical anchor, a proximal anchor element in extension;
FIG. 6 is a view of the device of FIG. 5, the proximal anchor element in retraction;
FIG. 7 illustrates an alternate embodiment of the endourethral device of the subject invention, particularly illustrating a distal mechanical anchor along with a proximal anchor element in extension, lateral flow permitted;
FIG. 7A is a section view of the device of FIG. 7 taken about line 7A-7A;
FIG. 8 illustrates a side view of the device of a further embodiment;
FIG. 8A illustrates the device of FIG. 8 with the length adjusted and secured;
FIG. 9 illustrates a side view of the device of yet a further embodiment with the length adjusted and secured;
FIG. 10 illustrates a side view of an insertion/inflation tool employed in the introduction of the devices of the previous figures;
FIG. 11 illustrates the preparation of the proximal portion of the insertion/inflation tool;
FIG. 11A illustrates the preparation of the distal extremity of the proximal tubular body;
FIG. 12 illustrates the preparation and loading of the distal anchor into the insertion/inflation tool;
FIG. 13 illustrates the prepared assembly prior to insertion into the urethra;
FIG. 14 illustrates the distal portion of the insertion/inflation tool; and,
FIG. 15 illustrates a representative urethral device of the subject invention in situ.

DETAILED DESCRIPTION OF THE INVENTION

A schematic of the human male urinary bladder and urinary passage (i.e., the lower urinary tract) is presented in FIG. 1. The bladder 30 temporarily stores urine 32 and periodically expels it when the bladder neck 34 opens, as the bladder 30 contracts. Urine 32 passes through the prostatic urethra 36, which is completely surrounded by the prostate 38. The distal limit of prostate 38 is marked by a small projection called the verumontanum 40. This is a important landmark because distal thereto, is the external urethral sphincter 42, which relaxes soon after the urination process begins. Beyond this is the urethra 44, affording a free passage of urine 32 external to body, beyond the external urethral meatus 46.
Generally referencing FIG. 2 (see also FIGS. 3, 5, and 7-9 having reference numerals +600, +700, +800, +900, and +1000 respectively, for like structures), there is shown an endourethral device 50 which generally comprises an elongate member 52 having proximal 54 and distal 56 segments, the elongate member 52 being positionable within the lower urinary tract so as to at least partially traverse the prostatic urethra. A proximal anchor 58, adapted to preferably abuttingly engage portions of the bladder neck so as to at least proximally anchor the device, is supported at least indirectly by the proximal segment 54 of the elongate member 52. The proximal anchor 58 includes bladder engaging elements 60 radially extending from a portion of the proximal segment 54 of the elongate member 52, urine being freely dischargable about at least the proximal segment 54 so as to substantially bathe the bladder neck therewith. Preferably, but not necessarily, the bladder engaging elements 60 radially extending from a body 64 of the proximal anchor 58 such that urine is freely dischargable about or around an exterior surface of the anchor body 64. A distal anchor 62, adapted to engage portions of the bulbous urethra so as to at least distally anchor the device, is supported by at least a portion of the distal segment 56 of the elongate element 52. The elongate member 52, may alternately be interposed (FIG. 3), or at least indirectly extend (FIGS. 5 & 7) between proximal and distal anchor elements or structures, as will be subsequently described.
As may be apparent from the aforementioned description, it is to be understood that the configuration or overall structure of the elongate member is highly variable, being dependent upon the sought after functionality of the endourethral device (i.e., the physiological condition being diagnosed and or treated). In an interventional setting, the elongate member generally provides a degree of support to assure patency of an intact but contracted lumen, see for example published PCT Application No. PCT/US01/24817 entitled ENDOURETHRAL DEVICE & METHOD, incorporated herein by reference (see WO 02/087412). Alternately, in a diagnostic setting for instance, the elongate member may comprise a selectively radial responsive segment for engagement with a portion of the urethra, namely the prostatic urethra. The radial responsive segment or diaphragm possesses a dual functionality, namely selective inward and outward radial responsiveness, in furtherance of qualitatively and/or quantitatively assessing fluid pressure and/or fluid flow through portions of the lower urinary tract, and memorializing the nature of the urethral structures (i.e., the architecture of the prostatic urethra and the relationship between the structures thereof) as by obtaining a casting, respectively, see for example, U.S. Pat. No. 6,719,709 entitled DIAGNOSTIC URETHRAL ASSEMBLY & METHOD, incorporated herein by reference, now U.S. Pat. No. 6,719,709.
Referring now to FIGS. 2 & 2A, the endourethral device (i.e., stent) shown includes a distal anchor 62 adapted to engage portions of the bulbous urethra, and a proximal anchor 58 adapted to abuttingly engage the bladder neck, the anchors being linked by a support element or structure 52. As aforementioned, form fits function relative to the elongate member or central segment of the endourethral device, in this instance a support element which includes a structurally supportive body 66 which is preferably coil wound of 0.012 inch round stainless steel which has been silicone encapsulated. A fluid conduit 68, to facilitate expansion of the reversibly expansive bladder engaging elements 60, distally extends along a longitudinal device axis from a filling manifold 70 to distal anchor 62. Emptying of the fluid system is accomplished by removing a plug 72 from a drain port 74 integral to at least the distal segment 56 of the elongate member 52, consistent with the methodology and structures described in published application serial no. PCT US01/24817, previously cited.
A tensile member 76 preferably extends adjacent the support body 66, shown parallel with fluid conduit 68, but is not limited to such arrangement. The tensile member 76 may extend directly adjacent fluid conduit 68, or alternatively, be wrapped around the perimeter thereof. As may be appreciated, the tensile member 76 may be surplusage (i.e., redundant), being eliminated when fluid conduit 68 is sufficiently rigid or adequately reinforced. In the preferred architecture of this device, the tensile member is compressible along the longitudinal axis under a relatively light force, however, the tensile member may also be constructed of a material which is relatively stiff axially such as stainless steel wire.
The proximal anchor 58 generally includes body 64 and bladder engaging elements 60 radially extending therefrom. In contradistinction to heretofore known bladder discharge aides, urine may be released from the lowest part of the bladder, often referred to as the bladder neck, urine being freely dischargable about/around an exterior surface of the body (i.e., a lateral flow condition) so as to substantially bathe the bladder neck.
The lateral urine flow path permitted by the proximal anchor, and the distal anchor as will later be presented, is beneficial for several reasons. First, the urine may more freely contact the bladder neck and bathe it. Second, the retained volume within the bladder is reduced following a urination event. Third, an internal passageway does not limit flow of urine to its boundaries. Urine may act in cooperation with the urethra. This is important. As an individual ages, the bladder function may weaken as a result of prostatic obstruction, or independently. The bladder micturition cycle is a work limited event. The muscle only contracts until it has spent the energy that is available to it. When the energy is spent, the muscles have tired, and will stop contraction regardless of the volume of urine remaining in bladder. This remaining urine is referred to as the post void residual (PVR), giving rise to at least two further implications. A high PVR requires a sooner return to the bathroom. If this is during sleeping hours, it will result in incomplete sleep and the deleterious effects associated therewith. Furthermore, a high PVR is widely viewed as contributing to at least the susceptibility to urinary tract infections.
The bladder engaging elements 60 of the proximal anchor 58 are advantageously circumferentially spaced apart about the surface of the anchor body 64. Preferably, but not necessarily, the engaging elements 60 are opposingly paired (FIG. 2A), but need not be so limited. It is further advantageous that the bladder engaging elements 60 be resilient, and preferably, be reversibly expandable (e.g., the bladder engagement elements 60 may be opposingly paired balloons as depicted in FIG. 2/2A). Preferably, the bladder engaging elements 60 are torpedo shaped when un-deflected by contact or otherwise unencumbered, this shape contributing only a minimum of flow resistance when properly filled. As is readily appreciated, low resistance is a critical consideration with respect to proper stable device placement within the lower urinary tract.
The interface of the resilient bladder engaging elements 60 relative to the anchor body 64, or proximal segment 54 of elongate member 52, along with the methodology and structure (i.e., insertion/filling tool) for reversibly deploying such endourethral device, or devices of this style, is generally disclosed in published PCT Application No. PCT US01/24817. Any modification or adaptation to accommodate the nature (i.e., structural) of the contemplated endourethral device is considered within the skill of a person of ordinary skill in the art.
The proximal anchor 58 further includes at least a pair of urine flow channels 78, each of the channels being defined or otherwise delimited by adjacent bladder engaging elements 60, see especially FIG. 2A. The urine flow channels 78 provide for high volumetric flow rates, and relatively complete bathing of the urethra with urine (i.e., the notion of device flow about or around a/k/a lateral flow). Urine flow is initiated when the external sphincter is dilated by the natural function of the body at the users initiation. As will be later generally detailed with respect to FIGS. 3-4, the distal anchor 62 may, as in the device of FIG. 2, have elements, and interrelationships therebetween, which substantially corresponding to those of the proximal anchor 58.
With continued reference to FIG. 2A, which illustrates the endourethral device in situ as viewed axially from proximal extremity 80, proximal anchor 58 secures the urethral device 50 from moving into the urethra (not shown in this view). The elongate member 52 may be advantageously provided with a passageway or lumen 82 to allow for introductions of fluids such as drugs, or antiseptics, or for filling the bladder by an insertion/inflation tool. This optional passageway may be closed or open following device insertion, however, it is preferable that the device of FIG. 2 have a closed passageway following removal of insertion device, the closure limiting the area available for static urine to form encrustation.
Referring now to FIGS. 3/3A & 4, an endourethral device 650, similar in general arrangement to that shown in FIG. 2 (i.e., having a common proximal anchor feature and elongate member comprising a helical support element), is shown incorporating a distal flow around anchor mechanism 662. The distal anchor 662 preferably, but not necessarily, includes a body 665 and urethral engaging elements 661 extending therefrom. More particularly, the urethral engaging elements 661 are circumferentially disposed, in a spaced apart condition, about an exterior surface of the distal anchor body 665, the elements 661 being radially extendible therefrom. The distal anchor 662 further includes at least a pair of urine flow channels 678, each of the channels 678 being delimited by adjacent urethral engaging elements 661. It should be readily appreciated that anchoring of an endourethral device may be satisfactorily accomplished by a proximal segment 654, distal segment 656, or a sharing of anchor function between each.
Endourethral device 650 has a proximal extremity 655 and a distal extremity 657. FIG. 3 illustrates device 650 having proximal anchor member 664 and distal anchor member 662 in a “filled” condition (i.e., the anchor elements 660, 661 of the device are in extension) whereas FIG. 4 illustrates device 650 without fluid in proximal anchor member 664 or distal anchor member 662 (i.e., the anchor elements 660, 661 of the device are in retraction). FIG. 3A is a centerline cross section of distal anchor member 662 of FIG. 3 illustrating filling conduit 668 in fluid communication with the interior of distal anchor 662. As may be appreciated, urine may easily flow adjacent distal anchor body 665 within the bulbous urethra. This particular device 650 may be best described in four sequentially aligned zones, namely, moving distally from the proximal end of the elongate member, zones I, II, III, and IV.
A passageway 682 extends through a first zone I from orifice 684 of the proximal end 654 of the elongate member 652. A second zone II, which dwells in the prostatic urethra consists of an open structure, namely an open pitched coil, which continues within a wall of the proximal portion 654 of the elongate member 652, and terminates by or in unified construction or attachment to a tensile member 676 (zone II) which further terminates in the distal zone IV containing anchor member 662. The tensile member 676 also converges or attaches to the extremity of proximal segment 654 for safety. The internal fluid communication between the first zone I and the distal anchor 662 is accomplished through conduit 668 which is shown axially separate from tensile member 676 though they are preferably in close proximity, or the same element.
The open structure of this endourethral device allows for the urine to contact the wall of the urethra and flow along the urethra as it drains. This has the beneficial effect, as likewise achieved via the structure of FIG. 2, of allowing for the natural secretions from the prostatic gland into the urethra to participate in their natural environment. These secretions are known to be beneficial as natural infection inhibitors as well as participating in sexual functions. Tensile member 676 is preferably constructed of a silicone coated silk suture material, or alternatively of a more rigid material such as a coated stainless steel wire.
Referring now generally to FIGS. 5-9, a mechanical distal anchor 762 is illustrated for an endourethral device, more particularly a wing type structure is shown tethered to an elongate member of an endourethral device. As emphasized throughout, a variety of devices may advantageously integrate the new anchor structures of the subject invention, singularly or in combination. For instance, the device of FIG. 5 illustrates heretofore known proximal anchoring in combination with mechanical anchor 762. In this style device, a circumferentially disposed bladder (shown uninflated in FIG. 6) is carried about the outer surface of a proximal portion of the elongate member for fully engaging a portion of the bladder neck. Proximally of the proximal anchor, the proximal portion of the elongate member is adapted, as via the inclusion of an aperture or plurality of same, to receive urine for passage interiorly of the elongate member (e.g., a tubular element). The device of FIG. 7 depicts an endourethral device having the flow around or lateral flow proximal anchor as shown and previously described with respect to FIG. 2.
Referring again generally to FIGS. 5-9, the distal anchor 762 (FIGS. 5 & 6, or 862 (FIG. 7/7A), 962 (FIG. 8/8A), 1062 (FIG. 9),) generally includes a body 765 having urethral engaging elements or portions 761 extending or depending therefrom, or otherwise integral thereto. As is readily appreciated by a review of the figures, the distal anchor element 762 is of particularly low profile (i.e., an insubstantial hindrance to urine discharge), being reversibly expanded following deployment (e.g., by discharge from an insertion tool or the like). The mechanical anchor preferably tapers toward a distal end thereof, such configuration aiding the retrieval of the mechanical anchor as will be discussed.
The distal anchor member 762 preferably, but not necessarily, includes a silicone encapsulated spring strut 786, or particular arrangement of struts or strut segments, either directly or indirectly extending from a central hub 788. When resiliently expanded, as for instance post deployment, the struts 786 expand to discretely engage portions of the urethral wall. In the configuration of FIG. 7A, it is noted that a portion of the elongate member 852 possesses a cruciform cross-section resulting from radially extending circumferentially spaced apart ribs 863.
Referring to FIG. 8, urethral device 950 is illustrated as an assembly. Urethral device 950 has a proximal extremity 955 and a distal extremity 957. Near the proximal extremity 955 is a port 984. Balloon 960 is located distal of port 984 on the extremity of tubular body 966. A second slidable tubular body 966 a is oriented around the outer periphery of tubular body 966. In the subject embodiment, tubular body 966 a is configured with at least one set of openings 969 a for registration with a series of spaced apart openings 969 of tubular body 966. The openings are provided for easy fixation of the tubular body 966 a with the slidable tubular body 966 using suture 971 or the like to secure the body elements.
Securing threads 977 are tied and encapsulated near the distal extremity 957, and extend to the distal anchor 962. These threads may be provided either pre-tied to provide a fixed initial length, or adjustable to provide the physician the ability to adjust per his measured requirements. Distal anchor 962 is mechanical in nature, lacking inflatable components, compare with the embodiment of FIGS. 3/4. It should be easily and readily appreciated that this adjustment mechanism and technique may be imported to other endourethral devices, and more generally, other known indwelling medical devices.
The anchor 962 is expanded, as illustrated, following deployment via encapsulated spring strut 963. When expanded, distal anchor 962 is approximately semi-circular at its expanded perimeter, and triangular longitudinally. Retrieval tether 993 is fixed to the distal extremity 957. Retrieval suture 990 is further joined to drain tether 992, which terminates in a drain plug 995, and removal tether 993. The mechanism and functions of the tethers are fully explained in the co-pending applications previously cited, and will not be further explained in this document.
Urethral device 950 of FIG. 8A is shown fixed in length. When the slidable tubular body 996 a has been moved longitudinally along the extremity of tubular body 996 such that a select, proper length is achieved, securing is accomplished by looping suture 971 through the passageway 969 a in the outer slidable tubular body 966 a, through passageways 969 in tubular body 966 and securing the suture ends. This results in a fixation of the body length. Alternatively, the length may be mechanically fixed using fasteners or mechanical retainers, as shown in U.S. Pat. No. 6,991,596, incorporated herein by reference. It may be appreciated that practicing urologists are also surgeons who are well accustomed to tying secure knots. For this reason, passageways 969 may be optionally removed for certain models when the urologist chooses to make his own passageways with a needle. This will not change the intent and or scope of this invention. Alternatively, the length may be mechanically fixed using fasteners or mechanical retainers such as clips, staples, or locking devices.
The tubular body 966 and the slidable tubular body 966 a are constructed from medical grade silicone material. These tubular bodies may be comprised of two separate tubular entities, or conversely single prolapsing construction. The interior of both tubes may be optionally reinforced to provide increased resistance to collapse. Suitable reinforcements include stainless steel coils or other means. The tubular bodies are preferably medical grade silicone or other suitable materials such as for example polyurethanes commonly used in urology applications.
Referring to FIG. 9, a further, non-limiting adjustable architecture is illustrated. Urethral device 1050 is illustrated with tubular body 1066, and second outer tubular body 1066 a. Urethral device 1050 is similar in function to urethral device 950 (FIG. 8), with the variation in that tubular body 1066 a is configured with an internal helical pattern, which cooperates with tubular body 1066. The body length is thereby adjusted by rotating one of the tubular bodies relative to the other.
Like the previous embodiment, when the “slidable” tubular body 1066 a has been moved longitudinally along the extremity of tubular body 1066 such that a select, proper length is achieved, securing is accomplished by looping suture 1071 through the passageways 1069 a in the outer slidable tubular body 1066 a, through passageways 1069 in tubular body 1066 and securing the suture ends. This results in a fixation of the body length.
The tubular body 1066 and the “slidable” tubular body 1066 a are constructed from medical grade silicone material. The interior of both tubes may be optionally reinforced to provide increased resistance to collapse. Suitable reinforcements include stainless steel coils or other means.
Referring to FIG. 10, an insertion tool 200 is illustrated for deploying the contemplated devices of the subject invention, with the combination illustrated in FIG. 13. Insertion tool 200 has a proximal extremity 202 and a distal extremity 204. Sealing rings 206 are intended to engage an interior surface of the proximal portion of the device as will later be explained. Anchor sleeve 208, which encapsulates a portion of elongate tube 210, restrains the distal anchor of the device within the interior of the tubular housing 212, and adjacent push cup 213, during device insertion or deployment. The elongate tube 210 is movable relative to tube 214 which is advantageously lined with coil 216. This movement is controlled from the proximal extremity, more particularly, via needle tip 218 of fluid filling port 219 as it is moved relative to barrel handpiece 220.
The following instructions for use describe an advantageous clinical use sequence. Preliminarily, remove the packaged urethral device and insertion/inflation tool; inspect the device and tool for damage; verify that balloon plug of the device is in place; and, flush tool with sterile water or saline to remove any air therein.
With reference to FIG. 11/11A, lubricate the sealing ring area of the tool with lubricant, e.g., K-Y Jelly. Similarly lubricate the lumen of urethral device, e.g., by injecting lubricant into distal end of the proximal tube. After lubrication, the tool, more particularly the proximal extremity thereof, may be inserted into the device's proximal tube portion until the proximal tip of the tool is fully seated into the proximal end of the device. For adjustable models, first determine device length and secure the tubes (i.e., tubular bodies) together to achieve a suitable length device. For non-adjustable models, select a suitably sized device.
Referring now to FIG. 12, following sterile preparation, retract the anchor sleeve or sheath of the tool so as to expose the push cup thereof. Hold the push cup, just distal of the anchor sheath, while inserting the distal end of the distal anchor of the device into the push cup. Note that the push cup is marked with a black indicator. Distal anchor end should be inserted so as to be positioned under the black indicator.
Thereafter, the distal anchor of the device is collapsed and wrapped around the shaft of the inflation tool. The wrapped distal anchor is then pushed or more generally inserted into the anchor sheath of the tool until the anchor is completely housed in the sheath. The spacer sleeve of the tool should abut the proximal end of the anchor sheath. The retrieval suture is then routed along the length of the tool.
In connection to device deployment, the device of the subject invention, in all its embodiments, is delivered in a similar fashion as a Foley catheter of equivalent profile. Slowly advance the device, i.e., the combination or assembly of FIG. 13, into the urethra, paying close attention to the resistance felt in the vicinity of the external sphincter. Do not use excessive force if unexpected resistance is encountered; do not continue without first determining the cause of resistance. Once the entire length of the assembly has been advanced, the proximal end of the device of the assembly will be in the bladder. Using a luer syringe, “inflate” the balloon of the proximal device portion via the needle tip of the inflation port with about 5 cc of sterile water or saline, at a rate of approximately 1 cc per second. Filling rates in excess of 1 cc/sec may result in incomplete balloon filling.
Positioning of the urethral device is accomplished by applying gentle traction to the tool using the inflation port (FIG. 14). Do not pull on the sheath hand piece. Pulling on the sheath hand piece may cause premature deployment of the distal device anchor. After resistance is felt, assuring that the now expanded proximal device balloon is positioned in/at the bladder neck, retract the anchor sheath by pulling on the sheath hand piece while holding the inflation port stationary. Pull the sheath hand piece until it stops sliding (i.e., sheath travel is approximately 1 inch or 2.5 cm), thereby indicating full sheath retraction.
Thereafter, apply gentle traction to the tool to “undock” (i.e., release) it from device, and then completely withdraw it from the urethra. The retrieval suture, color coded, may then be trimmed to an appropriate length such that the distal end is just inside the meatus (reference the deployed device of FIG. 15). Finally, the patient is to be instructed not to pull or otherwise manipulate the exposed/accessible portion of the tether as such action could “deflate” the distal device anchor, and dislodge the urethral device or cause expulsion of same.
As should be appreciated in connection with FIG. 15, and with reference to the device embodiments of FIGS. 8 & 9, in order to achieve the optimal treatment or therapy, an appropriate length device must be selected to accommodate the patients anatomical requirements. To size the device, measure the length of the prostate gland adjacent to the urethra. Careful measurement will help assure a properly fitting device. Other methods, such as direct measurement of the prostatic urethra length with inserted catheter-devices, can be used, if available, and transrectal ultrasound (TRUS) may likewise be utilized for such purpose. Finally, device of U.S. Pat. No. 6,719,709 are likewise suitable, and advantageous.

Using the prostatic urethra length, measured in centimeters (cm), match the measurement to the range defined in Column A of Table 1 herewith. Follow the row across to select the appropriate urethral device size in Column D.

TABLE 1


Urethral Device Size Selection Table

Column A
TRUS		Column C
Measurement		Prostatic
(Prostatic		Stent Length	Column D
Urethra	Column B	(Reference	Urethral
Length)	UMD Measurement	only)	Device Size

<2.4	<4	2.4	4
2.5 to 3.0	4.1-5.0	3.0	5
3.1 to 3.6	5.1-6.0	3.6	6
3.7 to 4.2	6.1-7.0	4.2	7
4.2 to 4.8	7.1-8.0	4.8	8
4.8 to 5.4	8.1-9.0	5.4	9

Generally, if the prostate length measurement exceeds 5.4 cm, the patient may not be a candidate for a urethral device, with device selection and insertion at the discretion of the physician, depending on the length of the obstructed region, adequate overall device size, and placement in the prostate anatomy.
As to preferred materials of construction, the endourethral device generally, but not necessarily utilizes a core construction of a 304 stainless steel wire coil encapsulated using implant grade silicone rubber (shore 30A, Rhoda Silicones, Inc., Ventura, Calif. PN V40029A & V40029B) to form a prostatic urethral stent. The proximal anchor of the device is bonded to the prostatic stent portion of the device. Bonding an anchoring balloon to a cast proximal tip forms the proximal anchor. The proximal tip is cast from silicone rubber (Rhoda Silicones). The anchoring balloon is extruded using an implant grade silicone rubber (NuSil Technology, Carpenteria, Calif., PN MED-4720), with the balloon being bonded using silicone adhesive (NuSil Tech. PN MEDl-4213).
The distal anchor is formed in the same fashion as the proximal anchor; a balloon is bonded to a distal anchor manifold. The proximal anchor and distal anchor are connected via an inflation lumen which is a medical grade silicone rubber tube (SF Medical, Hudson, Mass.; PN SFM3-1350) possessing a 0.020″ internal diameter and a 0.009″ wall thickness. The tube is attached to each anchor using silicone adhesive. The distal anchor manifold provides the location for receiving the drain plug of the anchoring balloons. The drain plug is formed from 304 stainless steel hypodermic tubing bonded/sealed to a size 1/0 silk suture using medical grade epoxy (TRA-CON, INC., Bedford, Mass.; PN TRA-BOND FDA2). When the plug is pulled from the distal anchor manifold port both the proximal and distal anchoring balloons deflate.
The device preferably uses a retrieval suture formed by size 1/0 silk suture, which is attached both to the distal end of the distal anchor and the distal end of the prostatic stent section. The retrieval suture traverses the length of the prostatic stent and attaches to the proximal end of the stent thereby limiting the amount of stent extension under tension. The use of silk provides flexibility due to its multiple strand construction while maintaining an acceptable break load limit.
The endourethral device may been fabricated in various lengths ranging from about 4 to 9 cm, the length measured from the distal end of the proximal balloon to the proximal end of the distal balloon. The ratio of the length of the prostatic stent to the remaining length (i.e., the length spanning the external sphincter) may be varied, presently the length ratio is 3:2 (i.e., for a 5 cm length device, the prostatic stent length is 3 cm). The external profile of the device may be fabricated from 10 French to 32 French.
This invention disclosure provides device configurations which achieve a sought after anchoring function and methodology. There are other variations of this invention which will become obvious to those skilled in the art. It will be understood that this disclosure, in many respects, is only illustrative. Changes may be made in details, particularly in matters of shape, size, material, and arrangement of parts without exceeding the scope of the invention. Accordingly, the scope of the invention is as defined in the language of the appended claim. As will further be appreciated, it is contemplated that the anchoring configurations of the subject invention be readily incorporated into known endourethral devices for diagnosis, managing or treating urological disorders, the benefits thereby accruing thusly being available generally to patient's presenting with such disorders.

Claims

1-21. (canceled)

22. An endourethral stent adapted to deliver an effective amount of therapeutic agent to a lower urinary tract, the endourethral stent comprising a proximal anchor structure for cooperative engagement with a bladder neck so as to prevent device migration toward a bulbous urethra, a distal anchor structure for cooperative engagement with at least portions of the bulbous urethra so as to prevent device migration toward the bladder, a selectively dimensionable body for selectively fixing a dimension corresponding to a distance between said proximal and distal anchor structures, said body including a segment adapted to permit physiological external sphincter function.

23. The endourethral stent of claim 22 further comprising means for selectively fixing said selectively dimensionable body of said device.

24. The endourethral stent of claim 22 wherein said distal anchor structure is non-rigidly linked to a portion of said selectively dimensional body.

25. The endourethral stent of claim 22 wherein said distal anchor structure non-rigidly extends from a portion of said selectively dimensional body.

26. The endourethral stent of claim 22 further comprising a non-rigid linkage, said non-rigid linkage connecting said distal anchor structure to a portion of said selectively dimensional body.

27. The endourethral stent of claim 26 wherein said non-rigid linkage comprises a single suture.

28. The endourethral stent of claim 26 wherein said non-rigid linkage comprises a configuration of multiple sutures.

29. The endourethral stent of claim 26 wherein said non-rigid linkage includes a free end terminating at a retrieval tether of said stent.

30. An endourethral device adapted to deliver an effective amount of therapeutic agent to a lower urinary tract, the endourethral device comprising a proximal anchor structure adapted to abuttingly engage at least portions of a bladder neck so as to at least proximally anchor said device, a selectively dimensionable body extending from said proximal anchor, and a distal anchor structure tethered to said body for engagement with a bulbous urethra.

31. The endourethral device of claim 30 wherein said body is longitudinally compactable.

32. The endourethral device of claim 31 wherein said body includes proximal and distal portions.

33. The endourethral device of claim 32 wherein said portions of said body are adapted for cooperative engagement.

34. The endourethral device of claim 32 wherein said portions of said body are selectively securable to each other.

35. A catheter apparatus comprising an endourethral stent assembly and an insertion tool slidably receivable within a portion of said endourethral stent assembly, said endourethral stent assembly comprising a proximal anchor structure adapted to abuttingly engage at least portions of a bladder neck so as to at least proximally anchor said stent subsequent to delivery, a selectively dimensionable body extending from said proximal anchor, and a distal anchor structure tethered to said body for engagement with a bulbous urethra subsequent to delivery.

36. The catheter apparatus of claim 35 wherein said insertion tool includes a tubular element translatable within a sheath, said tubular element having a proximal extremity adapted to deliver fluid to a proximal end portion of said endourethral stent assembly.

37. The catheter apparatus of claim 36 wherein said proximal extremity of said tubular element includes sealing rings for cooperative engagement with a proximal end portion of said endourethral stent assembly.

38. The catheter apparatus of claim 36 wherein said proximal anchor structure of said endourethral stent assembly includes at least a single fluid fillable element.

39. The catheter apparatus of claim 38 wherein said sealing rings of said tubular element traverse a fluid filling port of said at least a single fluid fillable element.

40. The catheter apparatus of claim 36 wherein said selectively dimensionable body of said endourethral stent assembly is translatable upon said proximal extremity of said tubular element, and said distal anchor structure of said endourethral stent assembly is reversibly retained in a proximal extremity of said sheath.

41. The catheter apparatus of claim 40 wherein said proximal extremity of said sheath includes a push cup, at least a portion of said distal anchor structure of said endourethral stent assembly confined thereby.

42. An catheter apparatus comprising an endourethral device, a retrieval system, and an insertion tool, said endourethral device comprising a stent body having a proximal fluid fillable anchor supported thereby, an expandable mechanical anchor non-rigidly linked to said stent body, said proximal fluid fillable anchor adapted to receive fluid via said insertion tool in furtherance of anchoring said device at a bladder neck, said retrieval system comprising a non-rigid tether having a first and second segments, said first segment terminating in a plug received by said fluid fillable anchor, said second segment passing through a portion of said device.