Ureteral Access Sheath
A sheath assembly and method for placing a sheath into a patient. The sheath assembly may include a sheath having a main lumen, a secondary lumen, and an opening between the main lumen and secondary lumen. A dilator tubing may be positioned in the main lumen. A guidewire and a safety wire may be provided with the sheath assembly. The method may include inserting the guidewire into a body passage of the patient, inserting a proximal end of the guidewire into a distal end of the dilator tubing, advancing the dilator tubing and sheath over the guidewire, inserting the safety wire through the secondary lumen of the sheath tubing prior to removing the guidewire and dilator tubing, and removing the guidewire and the dilator tubing from the sheath tubing.
This application is a continuation of U.S. patent application Ser. No. 14/569,353, filed Dec. 12, 2014, now U.S. Pat. No. 9,295,811, which is a continuation of U.S. patent application Ser. No. 14/094,611, filed Dec. 2, 2013, now U.S. Pat. No. 8,911,415, which is a continuation of U.S. patent application Ser. No. 10/840,882, filed May 7, 2004, now U.S. Pat. No. 8,597,261, which is a continuation-in-part of U.S. patent application Ser. No. 10/409,527, filed Apr. 8, 2003, now U.S. Pat. No. 7,654,989, each of which is entirely incorporated herein by reference.
BACKGROUNDIt is known to use a ureteral access sheath for creating an access channel from the external meatus to a location within the ureter of a patient to perform surgical procedures within the ureter and/or kidney. With an established channel to the ureter, a surgeon is able to insert and to withdraw a ureteroscope or other instrument more rapidly and with limited trauma to a patient's urinary system.
A typical prior art ureteral access sheath includes two subassemblies: a dilator and a sheath. The dilator is placed within the sheath, and the dilator and sheath combination is advanced through the urethra, through the bladder, and to the ureter. The dilator is then withdrawn, leaving the sheath in place. A ureteroscope is then advanced through the sheath to access the ureter.
A problem with known prior art ureteroscopic procedures concerns the need to irrigate the target site. Irrigation is critical during most ureteroscopic procedures. Since the inability to view the surgical area could have devastating effects, a procedure will not be continued until adequate viewing is achieved. Typically, irrigation fluid is supplied through the working channel of the ureteroscope. Because other instruments (i.e., a stone basket, grasper, laser fiber, etc.) also occupy the working channel, the flow rate of the irrigation fluid is reduced in proportion to the diameter of the instrument being used. Thus it would be desirable to provide a surgical environment in which the flow rate of irrigation fluid is not restricted by the presence of instruments within the working channel of the ureteroscope.
An additional problem with known prior art ureteral access sheaths concerns the need for guidewires in conjunction with the placement of the sheath. To use a typical prior art ureteral access sheath, the physician performs the following steps:
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- 1. A cystoscope is inserted into the patient's urethra and advanced into the bladder, where the ureteral orifices are identified.
- 2. Using the cystoscope, a guidewire is inserted into the ureteral orifice.
- 3. Using fluoroscopy, the proximal end of the guidewire is inserted through the ureter and into the kidney.
- 4. With the guidewire carefully held in place, the cystoscope is removed over the guidewire.
- 5. The dilator is placed within the sheath.
- 6. The distal end of the ureteral access sheath is now back-loaded onto the proximal end of the guidewire and advanced over the guidewire and into the ureter. Advancement and position of the ureteral access sheath is usually verified with fluoroscopy.
- 7. The dilator is removed from the sheath.
Now the sheath is in place to provide a working channel from outside the patient to the ureter. However, on occasion a surgical procedure may inadvertently puncture or lacerate the ureter. Normally, a secondary “safety wire” has been placed for access, in the event the access sheath needs to be adjusted or otherwise removed. The safety wire is normally placed alongside the sheath. Placement of the secondary safety wire requires a number of additional steps:
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- 8. The safety wire is inserted into the lumen of the sheath and advanced into the kidney.
- 9. With both the original guidewire and the safety wire held in place, the sheath is removed.
- 10. The dilator is placed into the sheath.
- 11. The sheath is back-loaded onto the initial guidewire as explained before and advanced into the ureter.
- 12. The dilator is removed from the sheath.
At this juncture, the sheath is in place, the original guidewire is disposed within the sheath, and the safety wire runs along the outside of the sheath. However, because the original guidewire occupies the same channel of the sheath into which the ureteroscope will be inserted, the original guidewire must now be removed before a surgical procedure can be commenced. Hence,
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- 13. The guidewire is removed from the sheath.
As can be seen, the requirement for a safety wire located outside the working channel of the sheath adds a number of steps and additional time and complexity to the procedure of positioning the sheath. In addition, the presence of the safety wire within the ureter alongside the sheath increases the possibility of lacerating the ureter.
In addition, some surgical procedures require the removal from the ureter of objects that are larger than the lumen of the sheath. In such instances, the objects are grasped against the distal end of the sheath, and the sheath must be completely withdrawn from the patient to extract the object. The sheath may be repositioned by once again placing the dilator into the sheath and advancing the sheath over the safety wire. However, there is now no safety wire running alongside the sheath. To position another safety wire alongside the sheath, the sequence of steps previously set forth must be repeated.
Thus there is a need for a ureteral access sheath which minimizes the number of steps required to position the sheath.
There is a further need for an improved ureteral access sheath which facilitates the placement of a safety wire.
SUMMARYIn one embodiment, an access sheath includes a sheath assembly including sheath tubing, the sheath tubing having a main lumen and a secondary lumen that extends along the length of the main lumen, the main lumen being large enough to receive an endoscope.
The disclosed ureteral access sheath will now be described with reference to the following drawings. Objects in the drawings are not necessarily drawn to scale.
Referring now to the drawings, in which like numerals indicate like elements throughout the several views,
The sheath assembly 12 includes an elongated sheath tubing 16 having a distal end 17 and a proximal end coupled to a hub 18. The hub 18 is partially encased within an elastomeric cover 20. A leader tube 22 is also coupled to the hub 18. A female luer fitting 24 is mounted to the proximal end 23 of the leader tube 22.
The dilator assembly 14 comprises a dilator tubing 26 having a dilator luer 28 attached to the proximal end of the tubing. A pair of locking tabs 29a, b are formed or otherwise provided at a distal portion of the luer 28.
Referring now to
The interior structure of the hub 18 is illustrated in
At the distal end 34 of the hub 18, an ovate opening 52 is vertically elongated and is wider at its lower end than its upper end. An oblong front chamber 54 communicates with a cylindrical bore 56. The cylindrical bore 56 coaxially joins the smaller cylindrical portion 50. A step 58 is formed where the larger cylindrical bore 56 meets the smaller cylindrical portion 50.
Referring now to the fitting 36 at the upper end of the hub 18, an opening 60 is formed in the end of the fitting. Within the opening 60 is a cylindrical bore 62. The cylindrical bore 62 coaxially joins a smaller cylindrical bore 64, creating a step 66 where the bores 62, 64 join. The opposite end of the smaller cylindrical bore 64 opens into the chamber 54 in the distal end 34 of the hub 18.
Referring now to
An elongated opening 80 is formed in the upper surface of the elastomeric cover 20. The opening 80 is rounded at its proximal and distal ends. The distal end of the opening 80 is in communication with a notch 82. A short elongated opening 84 is formed in the lower surface of the elastomeric cover 20.
A U-shaped housing 98 sits atop the tube 90 and defines a secondary lumen 100 disposed above the main lumen 90. The secondary lumen 100 is typically smaller than the main lumen so as to facilitate insertion of the sheath tubing 16 into a relatively small vessel, such as a urethra. However, the secondary lumen 100 is large enough to receive relatively small devices, such as a guidewire or a laser fiber. The secondary lumen 100 has a cross-sectional area that is a fraction of that of the main lumen 96. By way of example, the secondary lumen 100 ranges from about 1 Fr to about 6 Fr in size. In one embodiment, the secondary lumen 100 ranges from about 2 to about 4 Fr in size. The housing 98 terminates at distal and proximal locations 102, 104 respectively, that are spaced inward from the ends of the tube 90. Thus the secondary lumen 100 terminates at locations which are axially displaced inward from the ends of the main lumen 96. The termination of the housing 98 forms an outlet of the secondary lumen 100. This outlet tapers in the direction of the distal end 92 of the tube 90 to facilitate insertion into and passage through a body vessel.
As illustrated in
As is most clearly apparent from
Testing has been performed to evaluate the kink resistance of the sheath tubing 16. In this testing, the sheath tubing 90 was coiled around various cylinders of different diameters. Once coiled around a given cylinder, the sheath tubing 16 was visually inspected to determine if any kinking occurred. If no kinking occurred, the test was considered a “pass.” If kinking did occur, however, the test was considered a “fail.”
During the testing, each of 15 sheath assemblies, each having a length of 35 centimeters (cm) and a 15 Fr circumferential measurement, passed after having been coiled around a cylinder having an outer diameter of one inch (in). Passing the kink test for a cylinder having such a small diameter indicates that the sheath tubing 16 is unlikely to kink during use, even when traversing a tortuous path within the body.
Assembly of the ureteral access sheath 10 will now be explained with reference to
Next, as illustrated in
Referring now to
Use of the ureteral access sheath 10 to provide a working channel will now be explained with reference to
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- 1. A cystoscope is inserted into the patient's urethra and advanced into the bladder, where the ureteral orifices are identified.
- 2. Using the cystoscope, a guidewire 120 is inserted into the ureteral orifice.
- 3. Using fluoroscopy, the guidewire 120 is advanced through the ureter and into the kidney.
- 4.With the guidewire 120 carefully held in place, the cystoscope is removed over the guidewire.
- 5. Referring now to
FIG. 21 , the dilator assembly 14 is placed within the main lumen of the sheath assembly 12. The dilator assembly 14 is inserted into the sheath assembly 12 with the locking tab 29a of the dilator luer 28 oriented vertically. Then, when the dilator luer 28 is seated within the hub 18 of the sheath assembly 12, the dilator luer 28 is rotated 90° clockwise, and the locking tabs 29a, b on the dilator luer engage the locking slots 41a, b at the proximal end 32 of the hub 18 to lock the dilator assembly 14 to the sheath assembly 12. - 6. With further reference to
FIG. 21 , the proximal end 180 of the guidewire 120 is inserted into the distal end 121 of the dilator tubing 26. The guidewire 120 is advanced through the dilator tubing 26 and exits through the proximal end 25 of the dilator luer 28. - 7. The sheath assembly 12 with dilator assembly 14 in place is advanced over the guidewire 120 and into the ureter. Advancement and position of the ureteral access sheath is usually verified with fluoroscopy.
- 8.Referring now to
FIG. 22 , with the sheath assembly 12 in position with its distal end 123 within the ureter, the distal end 181 of a safety guidewire 122 is fed into the opening in the proximal end 27 of the luer fitting 24. The safety guidewire 122 is advanced through the lumen 110 of the leader tube 22 and into the small cylindrical bore 64, from where it enters the chamber 54 of the hub 18. The distal end 27 of the safety wire 122 then enters the secondary lumen 100 at the proximal end 104 of the housing 98 and traverses the length of the secondary lumen, exiting at the distal end 102 of the housing 98. - 9. With the safety guidewire 122 thus positioned, the dilator assembly 14 and main guidewire 120 are removed from the sheath assembly 12, as shown in
FIG. 23 .
Once the sheath assembly is in place to provide a working channel, a surgical procedure can commence. For example, a ureteroscope 125 has its distal end 126 introduced into the proximal end of the main lumen 96 of the sheath assembly 12, as shown in
The ureteral access sheath 12 of the disclosed embodiment thus provides a number of advantages over known prior art ureteral access sheaths. Because of the dual lumens 96, 100, the sheath assembly 12 can be configured as follows:
Device-Device. Both lumens can be occupied by medical devices. While the main working channel will most often be occupied by a ureteroscope, the secondary channel can be occupied by a safety guidewire, a laser fiber, a stone basket, a grasper, or any other medical device suitable to the procedure being performed. In the case of placing a safety guidewire in the secondary lumen, the sheath assembly 12 can be rapidly repositioned without the need for multiple backloads.
Device-Irrigation. The main working channel can be occupied by a ureteroscope, and the secondary working channel can be coupled to a source of irrigation such as a syringe, irrigation bag, irrigation system, or the like. Thus even when the main working channel of the ureteroscope is almost completely occupied by a surgical instrument, the surgical field can be irrigated efficiently by infusing the irrigation fluid through the secondary lumen.
Device-Device/Irrigation. The main working channel can be occupied by an instrument such as a ureteroscope 125. A Y-fitting can be attached to the female luer 24 of the leader tube 22. The safety guidewire 122 can be fed through the opening in one branch of the Y-fitting, and an irrigation means can be coupled to the other branch of the Y-fitting so that irrigation can be achieved while the safety guidewire is still in place within the secondary lumen 100.
Irrigation-Irrigation. The main working channel can be coupled to an aspiration means such as a Toomey syringe by locking the luer of the syringe into the tapered section 46 of the hub 18, and the secondary channel can be coupled to a source of irrigation such as a syringe, irrigation bag, irrigation system, or the like. Thus it is possible to irrigate the operative field through the secondary channel while aspirating the field through the main channel, setting up a turbulent flow in the operative field which is helpful in removing particles and debris.
As is depicted by directional arrows in
Due to the provision of the opening 170, damage to patient tissue can be avoided in cases in which the flow of irrigation fluid from the secondary lumen 164 is obstructed by that tissue. In such a situation, irrigation fluid, instead of being blocked, may pass out from the lumen outlet 172, in through the opening 170, and into the mail lumen 164. Such a situation is illustrated in
As is shown in
The pliability of the relatively soft tip 192 is illustrated in
Due to the relative rigidity obtained by the presence of the one or more secondary lumens, the ureteral access sheaths described in the foregoing can self-align when inserted through a patient vessel. An example of this phenomenon is illustrated in
This phenomenon occurs, at least in part, due to the relative stiffness of the side of the sheath tubing 200 that comprises the U-shaped housing 206. As described above in relation to
Because of this self-aligning action, the sheath tubing 200 automatically aligns itself within the body vessel in an orientation in which greater patency can be achieved. Specifically, the tubing 200 is aligned within the vessel so as to be more likely to remain open when a serpentine path is traversed. This phenomenon can be observed when multiple bends of a vessel are traversed.
As noted above, the presence of at least one secondary lumen increases the structural integrity of the sheath tubing of the ureteral access sheath and reduces kinking of the sheath during surgical procedures. Further kink resistance is provided when a guidewire, such as a safety wire, is inserted inside the secondary lumen in the manner indicated in
The presence of the guidewire 218 within the secondary lumen 214 provides additional strength to the sheath tubing 208 beyond that provided by the opposed walls 220 and the joint portions 222 (
Finally, it will be understood that the preferred embodiment has been disclosed by way of example, and that other modifications may occur to those skilled in the art without departing from the scope and spirit of the appended claims.
Claims
1. A method for placing a sheath into a patient, comprising:
- accessing a sheath assembly, comprising: a sheath, including a main lumen, a secondary lumen, and an opening between the main lumen and secondary lumen; a dilator tubing positioned in the main lumen; a guidewire; and a safety wire;
- inserting the guidewire into a body passage of the patient;
- inserting a proximal end of the guidewire into a distal end of the dilator tubing;
- advancing the dilator tubing and sheath over the guidewire;
- inserting the safety wire through the secondary lumen of the sheath tubing prior to removing the guidewire and dilator tubing; and
- removing the guidewire and the dilator tubing from the sheath tubing.
2. The method according to claim 1, wherein the sheath opening between the main lumen and the secondary lumen is adjacent a distal end outlet of the secondary lumen.
3. The method according to claim 1, wherein the main lumen of the sheath tubing has a first cross-sectional area, a first length, and a distal end outlet.
4. The method according to claim 3, wherein the secondary lumen has a second cross-sectional area less than the first cross-sectional area, a second length less than the first length, and a distal end outlet terminating proximal of the main lumen distal end outlet.
5. The method according to claim 4, wherein the sheath further comprises an opening adjacent the secondary lumen distal end outlet extending through a wall circumscribing the main lumen to provide access to the main lumen.
6. The method according to claim 1, further comprising:
- removing the sheath from the body passage of the patient without removing the safety wire;
- inserting the dilator tubing into the sheath main lumen;
- advancing the dilator tubing and sheath over the safety wire;
- inserting an additional safety wire through the secondary lumen of the sheath tubing prior to removing the safety wire and dilator tubing; and
- removing the safety wire and the dilator tubing from the sheath tubing.
7. The method according to claim 1, further comprising inserting a ureteroscope through the sheath main lumen.
8. The method according to claim 1, further comprising delivering irrigation fluid to a target site through the sheath secondary lumen.
9. The method according to claim 1, wherein the dilator tubing has a pliable tip.
10. The method according to claim 9, wherein the pliable tip has a Durometer hardness that ranges from about 50 A to about 65 D.
11. The method according to claim 9, wherein the pliable tip has a Durometer hardness that ranges from about 90 A to about 55 D.
12. The method according to claim 1, wherein the secondary lumen comprises opposed side walls that connect with the main lumen to form joint portions, the opposed side walls and the joint portions increasing a structural integrity of the sheath tubing to reduce kinking.
13. The method according to claim 12, wherein the opposed side walls of the secondary lumen comprise a tapered portion at the distal end outlet thereof.
14. The method according to claim 13, wherein the opening is positioned between the tapered portion of the opposed side walls.
15. The method according to claim 1, further comprising a hub that is coupled to a proximal end of the sheath tubing.
16. The method according to claim 15, further comprising an elastomeric cover that at least partially encases the hub.
17. The method according to claim 15, wherein the hub comprises first and second locking slots, and wherein the dilator assembly comprises first and second locking tabs, the method further comprising locking the first and second tabs of the locking slots to the first and second locking slots to lock the dilator assembly to the hub prior to the advancing step.
Type: Application
Filed: Mar 28, 2016
Publication Date: Jul 21, 2016
Inventor: Tracey E. Knapp (Lawrenceville, GA)
Application Number: 15/083,101