Clinical Evaluation of BackStop in Patients Undergoing Ureteroscopic Lithotripsy

Post FDA-Approval Clinical Evaluation of BackStopTM in Patients Undergoing Ureteroscopic Lithotripsy: A Prospective, Randomized Clinical Trial

The purpose of this clinical study is to evaluate BackStop, a polymer-based device that is intended to be used during ureteroscopic lithotripsy to prevent retrograde stone migration.

Study Overview

• Status: Terminated
• Conditions: Kidney Stones
• Intervention / Treatment: Device: BackStop

Detailed Description

During ureteroscopic treatment for ureteral stones, lithotripsy, irrigation, and manipulation of the stone often pushes stone away into the kidney itself. This phenomenon is called retropulsion, which is defined as clinically significant retrograde migration of stone or stone fragments. Movement of stones retrograde into the renal pelvis could potentially add and complicate the surgery further. Often scopes need to be changed in order to reach the stone, and chasing these stones will add time to the surgery and require more valuable resources. Furthermore, sometimes a second operation will need to be done when these retropulsed fragments could not be all found and cleaned out.

A number of devices have been developed to prevent such migration including stone baskets and conical devices. These are wire-based devices which have the potential of injuring the ureter. Because of safety concerns and that there is limited data available on the effectiveness of these devices; these are not widely used by urologists. BackStop has recently been developed as another tool to prevent retropulsion. It is a water soluble gel that is injected proximal to the stone. This creates a physical barrier that prevents stone migration during ureteroscopic lithotripsy for ureteral calculus.

• Study Type: Interventional
• Enrollment (Actual): 35
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • California
    • Los Angeles, California, United States, 90089
      • USC Institute of Urology
  • Virginia
    • Virginia Beach, Virginia, United States, 23462
      • Urology of Virginia

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• patient with solitary ureteral stone ranging from 5mm to 15mm diameter
• able to tolerate general anesthesia
• clinical indication for treatment by ureteroscopic lithotripsy
• must be willing and able to participate in any follow-up visits
• provide informed consent
• have a CT scan demonstrating the stone

Exclusion Criteria:

• patients undergoing extracorporeal shock wave lithotripsy (ESWL) or any other extracorporeal or percutaneous lithotripsy procedure as primary procedure
• any co-morbidity or condition that would necessitate exclusion of patient (physician opinion)
• renal or ureteral anatomical abnormality
• multiple stones in the indicated ureter
• stones in the indicated kidney
• patient is immunocompromised
• multiple organ dysfunction syndrome
• has an absolute or relative solitary kidney mass
• >= Stage 3 chronic kidney disease
• bilateral ureteral obstructing stones
• staghorn calculi
• impaction of several stone fragments (Steinstrasse)
• uncorrected coagulopathy/thrombocytopenia
• urethral and/or ureteral stricture
• reconstructive urinary surgery

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: BackStop; Patients randomized to the Experimental arm will receive the BackStop gel during their ureteroscopic lithotripsy to prevent retrograde migration of stones or stone fragments.	Device: BackStop; BackStop™ is a FDA approved device. It is intended for use during ureteroscopic lithotripsy to prevent retrograde migration of stones and stone fragments. It is comprised of a solution of a thermosensitive polymer, a purified version of poloxamer 407 having been fractionated in saline. BackStop™, which is injected above the stone, is provided in sterile, pre-filled 2.5ml and 5ml syringes along with and a corresponding injector and a catheter (3F or 5F).
No Intervention: Control; Patients randomized to the control group will not use any devices to prevent retrograde migration of stones and stone fragments during their ureteroscopic lithotripsy.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Rate of Prevention of Retrograde Stone or Stone Fragment Migration	Prevention of retrograde stone migration (Yes/No)	At the time of surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Stone-free Rate	Presence or absence of residual stone fragments at 2 month follow up after lithotripsy	2 months

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Need for Secondary Procedures	Need for secondary procedures of patients who had stone migration	Up to 3 months
Time for BackStop Injection	Time required to deliver BackStop beginning with insertion of BackStop catheter and ending with its removal subsequent to the delivery of BackStop	Minutes during Surgery
Duration of Lithotripsy Procedure	Duration of Lithotripsy Procedure	during surgery

Collaborators and Investigators

• Sponsor: University of Southern California
• Collaborators: Urology of Virginia
• Investigators: Principal Investigator: Matthew Dunn, M.D., USC Institute of Urology

Publications and helpful links

General Publications

• Segura JW, Preminger GM, Assimos DG, Dretler SP, Kahn RI, Lingeman JE, Macaluso JN Jr. Ureteral Stones Clinical Guidelines Panel summary report on the management of ureteral calculi. The American Urological Association. J Urol. 1997 Nov;158(5):1915-21. doi: 10.1016/s0022-5347(01)64173-9.
• International Conference on Harmonisation of technical requirements for registration of pharmaceuticals for human use.. ICH harmonized tripartite guideline: Guideline for Good Clinical Practice. J Postgrad Med. 2001 Jan-Mar;47(1):45-50. No abstract available.
• Hendrikx AJ, Strijbos WE, de Knijff DW, Kums JJ, Doesburg WH, Lemmens WA. Treatment for extended-mid and distal ureteral stones: SWL or ureteroscopy? Results of a multicenter study. J Endourol. 1999 Dec;13(10):727-33. doi: 10.1089/end.1999.13.727.
• Pardalidis NP, Kosmaoglou EV, Kapotis CG. Endoscopy vs. extracorporeal shockwave lithotripsy in the treatment of distal ureteral stones: ten years' experience. J Endourol. 1999 Apr;13(3):161-4. doi: 10.1089/end.1999.13.161.
• Chow GK, Patterson DE, Blute ML, Segura JW. Ureteroscopy: effect of technology and technique on clinical practice. J Urol. 2003 Jul;170(1):99-102. doi: 10.1097/01.ju.0000070883.44091.24.
• Knispel HH, Klan R, Heicappell R, Miller K. Pneumatic lithotripsy applied through deflected working channel of miniureteroscope: results in 143 patients. J Endourol. 1998 Dec;12(6):513-5. doi: 10.1089/end.1998.12.513.
• Robert M, Bennani A, Guiter J, Averous M, Grasset D. Treatment of 150 ureteric calculi with the Lithoclast. Eur Urol. 1994;26(3):212-5. doi: 10.1159/000475382.
• Rane A, Bradoo A, Rao P, Shivde S, Elhilali M, Anidjar M, Pace K, D'A Honey JR. The use of a novel reverse thermosensitive polymer to prevent ureteral stone retropulsion during intracorporeal lithotripsy: a randomized, controlled trial. J Urol. 2010 Apr;183(4):1417-21. doi: 10.1016/j.juro.2009.12.023. Epub 2010 Feb 20.

Helpful Links

• FDA MAUDE database online (accessed date July 8, 2007)

Study record dates

Study Major Dates

• Study Start: April 1, 2014
• Primary Completion (Actual): June 1, 2016
• Study Completion (Actual): July 1, 2016

Study Registration Dates

• First Submitted: April 18, 2014
• First Submitted That Met QC Criteria: April 22, 2014
• First Posted (Estimate): April 24, 2014

Study Record Updates

• Last Update Posted (Actual): May 22, 2019
• Last Update Submitted That Met QC Criteria: April 29, 2019
• Last Verified: April 1, 2019

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Kidney Diseases; Urologic Diseases; Pathological Conditions, Anatomical; Urolithiasis; Urinary Calculi; Calculi; Nephrolithiasis; Kidney Calculi
• Other Study ID Numbers: HS-12-00714

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No