Percutaneous Nephrostomy System

Abstract

A percutaneous nephrostomy catheter system includes a nephrostomy catheter lumen, an extension tubing and a collection bag. The extension tubing is inserted into the nephrostomy catheter lumen. The collection bag is fluidly coupled to the extension tubing. A percutaneous nephrostomy catheter system also includes a catheter hub which employs a Luer valve in order to facilitate nephrostomy care so that when the percutaneous nephrostomy system is in place urine flows from the renal pelvis into the nephrostomy catheter lumen, the extension tubing and the collection bag. The Luer valve employs a scalloped Luer-style male connector which, when screwed into the catheter hub allows flow.

Claims

1. An improved percutaneous nephrostomy catheter system 10 comprising: a. a nephrostomy catheter lumen; b. an extension tubing inserted into said nephrostomy catheter lumen; c. a collection bag fluidly coupled to said extension tubing; d. a catheter hub which employs a Luer valve in order to facilitate nephrostomy care so that when said percutaneous nephrostomy system is in place urine flows from the renal pelvis into said nephrostomy catheter lumen, said extension tubing and said collection bag.

2. An improved percutaneous nephrostomy catheter system according to claim 1 wherein said valve employs a scalloped Luer-style male connector which, when screwed into said catheter hub allows flow.

Description

DESCRIPTION OF THE DRAWINGS

[0045] FIG. 1 is a schematic drawing of a novel retention system that employs coaxial sleeves with radial deployment of the distal outer sleeve for renal anchoring mechanism, OTW=over the wire.

[0046] FIG. 2 is a schematic drawing of an end cap needleless connector and two-piece connector represent complete hub assembly from a standard venous access catheter repair kit.

[0047] FIG. 3 is a schematic drawing of a four-step procedure for attaching Medcomp two-part adaptor to catheter tubing.

[0048] FIG. 4 is a schematic drawing of a Luer-activated needleless valve which connects to hub of nephrostomy catheter.

[0049] FIG. 5 is a schematic drawing of a cross-sectional diagram along the long axis of the device in anchored configuration demonstrating the two-part hub securing the coaxial sleeves in relative position.

[0050] FIG. 6 is a schematic drawing of a cross-sectional diagram along the long axis of the device in anchored configuration. 1) outer coaxial sleeve, continuous with anchoring ribs at the distal, intra-corporal end of the catheter; 2) inner coaxial sleeve, continuous with the drainage side-holes at the distal end of the catheter; 3A) male-threaded inner component of hub, containing a circumferential slot within which the inner sleeve is inserted as well as a beveled outer surface; 3B) female-threaded outer component of hub, which serves as a lockring securing the two coaxial sleeves in relative position.

[0051] FIG. 7 is a schematic drawing of a conceptual prototype. Several longitudinal slits were created in the distal portion of an 8-French vascular sheath, representing the outer coaxial sleeve. An 8-French all-purpose drainage catheter (lighter shade of blue) was inserted within the lumen of the vascular sheath, representing the inner coaxial sleeve. Note: draining side-holes of the inner sleeve are not visualized in this photograph.

[0052] FIG. 8 is a schematic drawing of a cross-sectional (long axis) representation of the distal portion of the device in anchored configuration.

[0053] FIG. 9 is a schematic drawing of a color-coded cross-sectional (long axis) representation of the device in anchored configuration.

[0054] FIG. 10 is a schematic drawing of a close-up cross-sectional (long axis) diagram of the distal end of the catheter in anchored configuration. The inner and outer coaxial sleeves are permanently attached to each other at their distal ends, around their circumference, forming the distal end-hole (not pictured: drainage side-holes in the inner sleeve).

[0055] FIG. 11 is a schematic drawing of a cross-sectional diagram of the distal portion of the device in anchored configuration. Drainage side-holes of the inner coaxial sleeve are depicted and labeled as such.

[0056] FIG. 12 is a schematic drawing of a cross-sectional diagram of the distal portion of the device in anchored configuration with detailed, three-dimensional depiction of the portion of the inner coaxial sleeve containing the drainage side-holes.

[0057] FIG. 13 is a schematic drawing of a cross-sectional diagram of the distal portion of the device in anchored configuration with detailed, three-dimensional depiction of the portion of the inner coaxial sleeve containing the drainage side-holes.

[0058] FIG. 14 is a schematic drawing of a diagram depicting the parts for the repair kit. The luer, representing the needleless valve design. The cap representing the attaching site of the luer lock when conducting the repair.

[0059] FIG. 15 is a schematic drawing of the following steps for repairing a damaged nephrostomy tube at the site of the hub. (1) shows a damaged hub depicted by the dotted line, a common location for nephrostomy tube damage. (2). The first step in the repair process is to clamp the nephrostomy tube proximal to the site of damage and cutting the nephrostomy tube proximal to the damage site, yet distal to the clamp to prevent flow of fluid.

[0060] FIG. 16 is a schematic drawing of the next step which is to insert the cap into the nephrostomy tube. The cap will slide over the nephrostomy tube as depicted. (4) The next step is to screw in the new needleless valve into the cap.

[0061] FIG. 17 is a schematic drawing of a finally, when the clamp can be removed so that the nephrostomy tube can be used.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0062] In the prior art percutaneous nephrostomy catheter system, the prior art percutaneous nephrostomy catheter system includes a nephrostomy catheter lumen, an extension tubing, a collection bag, a 3-way stopcock assembly and a catheter hub. The primary function of a 3-way stopcock assembly is to enable flushing of the catheter lumen without disconnecting the extension tubing from the collection bag. Unfortunately, the 3-way stopcock assembly and the catheter hub are bulky and uncomfortable, partly contributing to decreased quality of life for patients.

[0063] Referring to FIG. 1 an improved percutaneous nephrostomy catheter system 10 provides refinements in its design which center around the primary goals of 1) improving patient comfort/user friendliness and 2) enabling simple, lower risk and inexpensive clinic or bedside repair in the case of fracture of the external catheter. The improved percutaneous nephrostomy catheter system 10 includes a nephrostomy catheter lumen 11, an extension tubing 12, a collection bag 13, and catheter hub 15 to facilitate nephrostomy care while eliminating the need for the 3-way stopcock assembly. When the percutaneous nephrostomy system 10 is in place urine flows from the renal pelvis into the nephrostomy catheter lumen 11 and into the extension tubing 12 and the collection bag 13.

[0064] Still referring to FIG. 1 a retention system employs coaxial sleeves with radial deployment of the distal outer sleeve for renal anchoring mechanism over the wire (OTW).

[0065] Referring to FIG. 2 is an end cap needleless connector and two-piece connector represent complete hub assembly from a standard venous access catheter repair kit.

[0066] Referring to FIG. 3 a four-step procedure for attaching Medcomp two-part adaptor to catheter tubing.

[0067] Referring to FIG. 4 is a Luer-activated needleless valve which connects to hub of nephrostomy catheter.

[0068] Referring to FIG. 5 in conjunction with FIG. 1 the valve employs a proprietary scalloped Luer-style male connector which, when screwed into the hub 14 allows flow. When the extension tubing 12 is attached to the catheter hub 14, urine flows from the nephrostomy catheter into the collection bag 13. In preparation for flushing the improved percutaneous nephrostomy catheter system 10, a scalloped Luer-style male adaptor is attached to the standard saline flush syringe and the adaptor-syringe combination is screwed into the catheter hub 14. As with the extension tubing 12, the scalloped male connector compresses the valve allowing flow. When connected to the proprietary scalloped male connector, the valve design allows for bidirectional flow.

[0069] Referring to FIG. 4 in conjunction with FIG. 2 catheter repair involves cutting off the damaged section and installing a new hub. This process would also cut the retention suture holding the pigtail shape. The improved percutaneous nephrostomy catheter system 10 employs a retention system which is similar to the coaxial Malecot catheter design with some key differences. Actuation of the retention system into the expanded fixation position, versus the collapsed introduction or removal position, depends on the relative position of the two coaxial sleeves that make up the catheter. The outer sleeve has several longitudinal perforations located around the circumference of its distal end, forming struts oriented radially. The inner sleeve is reinforced and contains multiple side holes in the same region of the longitudinal perforations of the outer sleeve. The two sleeves are fused at the distal end-hole. To prevent formation of a tissue bridge which can hinder removal, our proposed design includes a thin, flexible synthetic membrane, either silicone or ePTFE, forming a partial web over the angles between the proximal struts. Following advancement into the renal pelvis, the outer sleeve is driven toward the patient and the inner sleeve is maintained static, causing the struts of the outer sleeve to flare outwards radially in an inverted V shape and the sleeves can be clamped in order to maintain their position relative to one another. The catheter (both inner and outer sleeves) is cut to a custom length chosen according to the specific ergonomic needs of the patient. At this point the hub containing the spring-loaded ball valve within the female end of the Luer-style connection is fastened to the catheter employing a system in a similar fashion to repairable venous access devices or implantable infusion ports. Repair of the nephrostomy catheter simply involves clamping the catheter with padded or atraumatic hemostat or clamp to secure deployed shape of the retention system within the renal pelvis, cutting the catheter proximal to the site of damage, and attaching a new hub as described above. The two-piece connector would serve dual duty: 1) connecting the catheter tube to the valve component; and 2) holding the two catheter sleeves in their relative positions in order to maintain the deployed configuration of the distal anchoring mechanism (the Malecot-style system).

[0070] Referring to FIG. 9 a color-coded cross-sectional (long axis) representation of the device is shown in anchored configuration.

[0071] Referring to FIG. 10 a close-up cross-sectional (long axis) diagram of the distal end of the catheter is shown in anchored configuration. The inner and outer coaxial sleeves are permanently attached to each other at their distal ends, around their circumference, forming the distal end-hole (not pictured: drainage side-holes in the inner sleeve).

[0072] Referring to FIG. 11 a cross-sectional diagram of the distal portion of the device is shown in anchored configuration. Drainage side-holes of the inner coaxial sleeve are depicted and labeled as such.

[0073] Referring to FIG. 12 a cross-sectional diagram of the distal portion of the device is shown in anchored configuration with detailed, three-dimensional depiction of the portion of the inner coaxial sleeve containing the drainage side-holes.

[0074] Referring to FIG. 13 a cross-sectional diagram of the distal portion of the device is shown in anchored configuration with detailed, three-dimensional depiction of the portion of the inner coaxial sleeve containing the drainage side-holes.

[0075] Referring to FIG. 14 a diagram depicts the parts for the repair kit. The luer represents the needleless valve design. The cap represents the attaching site of the luer lock when conducting the repair.

[0076] Referring to FIG. 15 the following steps for repairing a damaged nephrostomy tube at the site of the hub are as follows: (1) shows a damaged hub depicted by the dotted line, a common location for nephrostomy tube damage. (2). The first step in the repair process is to clamp the nephrostomy tube proximal to the site of damage and cutting the nephrostomy tube proximal to the damage site, yet distal to the clamp to prevent flow of fluid.

[0077] Referring to FIG. 16 the next step is to insert the cap into the nephrostomy tube. The cap will slide over the nephrostomy tube as depicted. (4) The next step is to screw in the new needleless valve into the cap.

[0078] Referring to FIG. 17 when a clamp can be removed then the nephrostomy tube can be used.

[0079] This ubiquitous device utilizes a silicone valve seal which opens upon insertion of any standard male Luer-lock fitting. Some manufacturers recommend replacement of these valves every three days, this is based upon usage as an intravenous infusion fitting. Testing would be required to elucidate the appropriate replacement interval for these valves in the setting of urinary diversion. Luer-activated needleless valves may represent a solution with very low development and manufacturing cost.

[0080] The improved percutaneous nephrostomy system 10 incorporates design elements used in percutaneous catheters, e.g. Malecot nephrostomy and suprapubic catheters, repairable hemodialysis catheters and luer-activated valves. Regarding outside diameter of the catheter relative to the luminal diameter, the coaxial design would sacrifice no more than 1-2 French of luminal diameter. Both versions of the valve design, the novel ball-spring-valve and the existing luer-activated valve, represent low cost solutions to significant problems of patient quality of life and repairability of percutaneous nephrostomy. These refinements in this percutaneous nephrostomy catheter design center around the primary goals of 1) improving patient comfort/user friendliness, 2) improving stability against dislodging, and 3) enabling simple, lower risk, and inexpensive clinic or bedside repair in the case of fracture of the external catheter. The stopcock facilitates flushing without leakage while adding to the bulk of the external portion of the drainage system, negatively impacting patient comfort and QoL. A thin-walled, large lumen Luer-activated valve may be inserted onto the hub. The Luer-activated valves prevent leakage upon disconnecting the extension tubing during bag emptying, flushing and allows for bi-directional flow upon insertion of Luer-lock counterpart. The current Luer-activated valves are ubiquitous in the setting of venous access catheters and IV tubing (infusion of drugs) current valves have a luminal diameter equivalent to that of an 18-gauge needle (0.84 mm) while typical 8 Fr nephrostomy catheters have a luminal diameter of 1.7 mm. This 50% bottleneck would create flow restriction if used in nephrostomy systems, especially in patients with viscous urine. A large-bore Luer-activated design with unique internal construction allowing 1.7-2 mm of luminal diameter is recommended. The locking pigtail designs are the current standard in nephrostomy and other percutaneous drainage catheters. The design is not without issues. The pigtail conformation of the distal catheter depends on a thin string. Failure of this retention string is not uncommon, leading to catheter displacement a hospital visit for replacement/exchange. This design totally precludes any repair of external catheter fracture (i.e. near hub), as cutting the catheter would transect the retention string. The solution is a coaxial radial retention system. The catheter is made up of two coaxial sleeves fused at the distal end hole. The distal part of the outer sleeve has several (4-8) linear, longitudinal perforations, which upon actuation of the retention system create several V-shaped retention struts oriented radially around the axis of the catheter. The inner sleeve contains multiple side holes in the same region of the longitudinal perforations of the outer sleeve and is reinforced to provide support for the retention struts. This is not a Malecot-style catheter. Malecot catheters rely on tension in the pre-bent struts and contains no coaxial support component. The only thing in common with our design is the radial orientation of V-shaped struts. Actuation of the retention system into the expanded fixation position versus the collapsed introduction or removal position depends on the relative position of the two coaxial sleeves that make up the catheter. Once advanced into the renal pelvis, the outer sleeve is driven toward the patient and the inner sleeve is maintained static, causing the struts of the outer sleeve to flare outwards and assumed their V-shape. The hub design allows the catheter tip to be locked in this configuration. The two components of the hub are the main hub with a male nozzle fitted and welded to inside of inner sleeve from factory with the sleeve flared outward around male nozzle to preserve luminal diameter and the male threads on external surface of main hub to accept outer collar and the outer collar (compression-collar) with female thread to fasten onto main hub, effectively compressing the two sleeves together a fixation of distal catheter in retention conformation. The outer collar is supplied free-floating around the outer sleeve. This design also allows repair in case of external catheter fracture by simply clamping the catheter with padded or atraumatic hemostat or clamp to secure deployed shape of the retention system within the renal pelvis, cut the catheter proximal to the site of damage and attach a new hub as described previously. If there are concerns of tissue bridge formation hindering full collapse for removal, our proposed design could include a thin, flexible synthetic membrane, either silicone or urethane, forming a web over the parts of the struts adjacent to the calyx wall.

[0081] From the foregoing it can be seen that an improved percutaneous nephrostomy system has been described. It should be noted that the sketches are not drawn to scale and that distances of and between the figures are not to be considered significant.

[0082] Accordingly, it is intended that the foregoing disclosure and showing made in the drawing shall be considered only as an illustration of the principle of the present invention.

REFERENCES

[0083] 1. Dagli, M., & Ramchandani, P. (2011). Percutaneous Nephrostomy: Technical Aspects and Indications. Seminars in Interventional Radiology, 28(04), 424-437. doi:10.1055/s-0031-1296085 [0084] 2. Fingar, K. R., Stocks, C., Weiss, A. J., & Steiner, C. A. (2014, December). Most Frequent Operating Room Procedures Performed in U.S. Hospitals, 2003-2012. Retrieved Feb. 2, 2019, from https://www.hcup-us.ahrq.gov/reports/statbriefs/sb186-Operating-Room-Procedures-Unit ed-States-2012.jsp [0085] 3. Percutaneous Nephrostomy. (2018, February 26). Retrieved Feb. 7, 2019, from https://www.dovemed.com/common-procedures/procedures-surgical/percutaneous-nephrostomy/ [0086] 4. Nephrostomy Catheter Placement. (2019). Retrieved Feb. 7, 2019, from https://www.mdsave.com/procedures/nephrostomy-catheter-placement/d581facb [0087] 5. Noureldin, Y. A., Diab, C., Valenti, D., & Andonian, S. (2016). Circle nephrostomy tube revisited. Canadian Urological Association Journal, 10(7-8), 223. doi:10.5489/cuaj.3596 [0088] 6. Assimos, D. (2015 Jul. 1). Re: Determinants of Nephrostomy Tube Dislodgment after Percutaneous Nephrolithotomy. Retrieved from https://insights.ovid.com/pubmed?pmid=26088231# [0089] 7. Nephrostomy. (2017 Jul. 26). Retrieved from https://www.insideradiology.com.au/nephrostomy/ [0090] 8. Bayne, D., Taylor, E. R., Hampson, L., Chi, T., & Stoller, M. L. (2015). Determinants of nephrostomy tube dislodgment after percutaneous nephrolithotomy. Journal of endourology, 29(3), 289-92. [0091] 9. Sarkar, D., & Parr, N. J. (2018 Jul. 1). Dislodged nephrostomy: A top tip. Retrieved from https://innovations.bmj.com/content/4/3/113 [0092] 10. Lewis, S., & Patel, U. (2004, February). Major complications after percutaneous nephrostomy-lessons from a department audit. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/14746788 [0093] 11. Cielli, C. (2019 January 28). Insufficient sleep: Definition, epidemiology, and adverse outcomes. Retrieved Feb. 7, 2019, from https://www.uptodate.com/contents/insufficient-sleep-definition-epidemiology-and-adverse-outcomes?search=sleep quality&source=search_result&selectedTitle=1150&usage_type=default& display_rank