NephrolithiasisPhase 4NCT03229889
Trial of Tadalafil, Tamsulosin and Combination for Access Sheath Deployment
A Phase 4 study testing Cialis 5Mg Tablet, Flomax 0.4Mg Capsule and Cialis + Flomax in people with Nephrolithiasis, run by University of California, Irvine at 1 site in United States.
Trial summary
Extensive literature exists on the use of alpha-blocker medications for the removal of kidney stones. Alpha blockers relax certain muscles and help small blood vessels remain open. Read more about this study
- Who is it for?
- Ages 18 to 99 years
- Conditions the study is for
- Nephrolithiasis
- What is being tested?
- Cialis 5Mg Tablet, Flomax 0.4Mg Capsule and Cialis + Flomax
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 220 participants
- Where
- 1 siteUnited States
- Study dates
- 7 Jun 2017to 24 Mar 2022
- Phase
- Phase 4
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 99 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Patients undergoing percutaneous nephrolithotomy (PCNL) or ureteroscopy (URS) for renal or proximal ureteral urolithiasis
- A documented sterile urine culture within 1-2 weeks of the procedure
- ≥ 18 years old
- Ability to understand and the willingness to sign a written informed consent
Who cannot join
- Patients < 18-years-old
- Presence of ureteral stent or nephrostomy tube prior to scheduled procedure
- Patients requiring open, endoscopic, or laparoscopic procedure in the same setting as the intended URS or PCNL
- Planned concurrent bilateral endoscopic ureteral procedures
- Patients currently taking alpha-blockers within 14 days of surgery
- Patients taking PDE-5 inhibitors within 14 days of surgery
Show all 18Show fewer
- Pregnant women
- Active urinary tract infection (UTI) or uncontrolled HIV
- Uncorrected coagulopathy
- Patients who cannot stop their blood thinners, and/or non-steroidal anti-inflammatory medications 5-7 days prior to the procedure
- Patients allergic to tamsulosin or tadalafil
- Patients with upcoming cataract surgery due to risk of floppy iris syndrome
- Patients with history of priapism
- Patients with hereditary retinitis pigmentosa
- Patients concurrently using nitrates for myocardial infarction (MI) or angina
- Patients with high risk cardiovascular disease: left ventricular outflow obstruction, MI in last 90 days, unstable angina, stroke in last 6 months, uncontrolled arrhythmias
- Patients with renal impairment (CrCl < 30 mL/min) or severe hepatic impairment (Child-Pugh score ≥ 10)
- Patients using CYP3A4 inhibitors such as clarithromycin, ritonavir, ketoconazole, or Iitraconazole
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Medication Facilitated Ureteral Access Sheath Deployment During Ureteroscopy and Endoscopic-Guided Percutaneous Nephrolithotomy: A Randomized Double-Blind Placebo Controlled Trial of Tadalafil, Tamsulosin and Combination
Extensive literature exists on the use of alpha-blocker medications for the removal of kidney stones. Alpha blockers relax certain muscles and help small blood vessels remain open. They work by keeping the hormone norepinephrine (noradrenaline) from tightening the muscles in the walls of smaller arteries and veins, which causes the vessels to remain open and relaxed. This improves blood flow and lowers blood pressure. There are studies that demonstrate alpha-blockers decrease ureteral pressure and help the ureter "relax."
Recent studies have shown that phosphodiesterase inhibitors may also help with ureteral stone passing. A phosphodiesterase inhibitor is a drug that blocks an enzyme that inhibits relaxation of smooth muscle. This means that it can help smooth muscle, such as the muscle that lines the ureter, to relax. While ureteral relaxation is helpful in the passage of ureteral stones, our study seeks to use this finding by pretreating participants with an older generation alpha blocker or a phosphodiesterase inhibitor prior to passage of a ureteral access sheath in cases in which ureteroscopy is being used to approach a ureteral or renal stone.
Read more
By relaxing the ureter, it is possible that a larger access sheath can be safely placed. This may allow for facilitating passage of the ureteroscope and extraction of stone fragments while precluding the development of potentially damaging intrarenal pressure from the flow of irrigant. The ureteral access sheath also protects the ureter from damage during the procedure. Placement of the largest access sheath possible is helpful in that larger stone fragments can be retrieved, the flow of irrigant is improved, and the surgical field is kept clear of blood or debris. To date, nobody has studied whether use of an uro-selective alpha blocker, alone, or in combination with a 5 phosphodiesterase inhibitor will result in passage of larger access sheaths.
In this study participants will be randomized into 1 of 4 categories: Flomax (alpha-blocker), Cialis (5-phosphodiesterase inhibitor), a combination of the 2, or a placebo arm. In this study the placebo, or no active drug, is the current standard of care and will serve as a control from the other 3 groups.
Read the detailed description
Technological improvements such as the miniaturization and development dual lumen ureteroscopes have improved the urologists' ability to treat urolithiasis1. The quality of flexible ureterorenoscopy is dependent on adequate visualization of the upper urinary tract. Adequate irrigation and visualization are compromised by debris from stone fragmentation and/or any bleeding during treatment. Fortunately, use of an ureteral access sheath (UAS) increases irrigant flow and reduces intrarenal pressure 2.
Ureteral access sheath technology was significantly improved by a member of our investigative team (RVC) thereby making it more widely acceptable3-5. The design changes allowed for easier deployment of the access sheath and the newer design was made to be kink resistant. This iteration of the device is easily deployed over a guidewire and has varying lengths such that it can be passed to the level of the stone in each case. Today's ureteral access sheaths range in size from 11-French to 16-French in diameter. The use of a ureteral access sheath has been shown to decrease intraoperative time, provide higher stone free rates, incur less cost due to shorter operating room times, and lead to fewer secondary procedures5,6. The access sheath should also, in theory, lower the risk of urinary tract infection due to decreased intrarenal pressure thereby resulting in less pyelovenous and less pyelolymphatic backflow. Lastly, use of an access sheath minimizes damage to the fragile flexible ureteroscope and thus increases their longevity while decreasing repair costs7.
Despite the above findings use of the UAS has not been universally embraced. A single study by Traxer et al., showed the incidence of low grade ureteric injury using UAS was 46% and that with serious injuries (i.e. urothelial tears) occurred in 13%8. However, a follow-up study by the same group showed no evidence of delayed long-term ureteral stricture formation; in fact, the patients who had a ureteral access sheath deployed there was a lower risk of post-operative complications9. Further, other studies have shown that the rate of ureteral stricture formation following use of a ureteral access sheath is 1.4% compared to a baseline rate of 1-3% during routine ureteroscopy without an access sheath10. In the afore cited study, the solitary occurrence of a post-ureteral access sheath ureteral stricture occurred at the ureteropelvic junction in a patient who underwent four endoscopic procedures for struvite stones; in all four surgeries, the access sheath was deployed at the level of iliac vessels well below the site of the patient's stricture10. Of note, porcine models have shown decrease ureteral blood flow following the acute deployment of a large access sheath, however over time the flow normalized and in follow-up there was no increase in post procedural ureteral stricture formation11.
Most urologists who place a ureteral access sheath do so without any pretreatment for ureteral relaxation. At our institution, the investigators routinely use alpha blockers (tamsulosin) as an adjunctive medical therapy to possibly relax the ureteral muscle; the medication is begun one week prior to surgery as it takes five days for the medicine to reach a steady state. It has been the investigator's experience that they are able to place larger ureteral access sheaths (i.e. 14 and 16 French size) with this approach. Additionally, examination of the ureter at the end of the procedure has shown minimal effect from placement of the access sheath; to date, the study team has not had any patient return with a post procedural ureteral stricture. Of note, it is the investigator's practice that if there is any resistance to deployment of the ureteral access sheath, then a smaller sized sheath is used; should the smaller sheath encounter resistance to its passage then a ureteral stent is placed and the procedure is postponed for a week. Stent placement in a ureter facilitates subsequent placement of an access sheath8,12.
An extensive literature exists on the role of alpha-blocker medications on the relaxation of ureteral smooth muscle13. This is due to the numerous alpha-1 receptors along the ureter, particularly in the distal ureter14,15. This knowledge originally led to the development of medical expulsive therapy in the treatment of ureteral stones. Several meta-analyses have shown that alpha blockers help passage of distal ureteral stones in the 5-10mm range, in less time and with less pain. The most extensively studied medication in this regard has been tamsulosin In addition to alpha blockade, recent in vitro studies have shown that phosphodiesterase-5 (PDE-5) inhibitors such as a tadalafil, commonly known by its tradename Cialis, also facilitate ureteral relaxation18-20. This has been substantiated by clinical studies which showed that sildenafil compared to placebo improved stone passage by 27%21. Further when tadalafil was added to tamsulosin the result was improved stone passage; the combined medications were well tolerated22,23.
- Conditions
- Nephrolithiasis
- Being tested
- Cialis 5Mg Tablet, Flomax 0.4Mg Capsule, Cialis + Flomax, Placebo
- Keywords
- Access Sheath, PCNL, Percutaneous Nephrolithotomy, Ureteroscopy, Alpha Blocker, Flomax, PDE-5 Inhibitor, Cialis, Phosphodiesterase Inhibitor
- Medical subject headings
- Nephrolithiasis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Cialis 5Mg TabletDrug
Also called Tadalafil
Cialis is a PDE-5 inhibitor that has been shown to relax smooth muscle. Patients will be asked to 1 pill for 7 days prior to surgery.
Flomax 0.4Mg CapsuleDrug
Also called Tamsulosin
Tamsulosin is an alpha-blocker that has been shown to relax smooth muscle in the genitourinary system. Patients will be asked to 1 pill for 7 days prior to surgery.
Cialis + FlomaxCombination product
Also called Tamsulsoin, Tadalafil
Cialis is a PDE-5 inhibitor that has been shown to relax smooth muscle. Tamsulosin is an alpha-blocker that has been shown to relax smooth muscle in the genitourinary system. A combination of these two drugs may increase the relaxation effects in the ureter. Patients will be asked to 1 of each pill for 7 days prior to surgery.
PlaceboDrug
Also called Inactive Drug
This is plant cell based pill that contains no active ingredient. Patients will be asked to 1 pill for 7 days prior to surgery.
| Study group | Role | What they receive |
|---|---|---|
| Flomax + Placebo | Active comparator | Patients will be prescribed Flomax 0.4Mg Capsule and given a bottle of placebo. They will be instructed to take 1 of each pill for the seven days prior to their surgery. Receives: Drug: Flomax 0.4Mg Capsule |
| Cialis + Placebo | Active comparator | Patients will be prescribed Cialis 5Mg tablet and given a bottle of placebo. They will be instructed to take 1 of each pill for the seven days prior to their surgery. Receives: Drug: Cialis 5Mg Tablet |
| Cialis + Flomax | Active comparator | Patients will be prescribed .4mg of Flomax and 5mg of Cialis. They will be instructed to take 1 of each pill for the seven days prior to their surgery. Receives: Combination Product: Cialis + Flomax |
| Placebo + Placebo | Placebo comparator | Given 2 bottles of placebo. They will be instructed to take 1 of each pill for the seven days prior to their surgery. Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Passage of 16F Access Sheath
Our primary objective is to assess the ability of a uroselective alpha-blocker (tamsulosin) and PDE-5 inhibitor (tadalafil), either alone or in combination will facilitate the passage of a 16F ureteral access sheath. Successful deployment will be defined as passage of the 16F ureteral access sheath into the proximal ureter or ureteropelvic junction. Difficulty in passing a 16F ureteral access sheath will be defined as a "failure". In this situation, we will place smaller ureteral access sheath (i.e. 11F or 14F), or opt to place a stent to dilate the ureter, and plan for surgery in the future; this is standard of care.
Measured: This will be assessed immediately post-op per patient.
Secondary outcomes (4)
Injury
Assessment of ureteral wall injury as defined by the post-ureteroscopic lesion score (PULS) as recorded during removal of the access sheath at the end of the surgical procedure
Measured: This will be assessed immediately post-op per patient.
Complications
Intraoperative complications will be recorded as defined by the Clavien-Dindo scale.
Measured: This will be assessed post-op per patient.
Adverse events
Incidence of adverse events with medications versus placebo as obtained during history on day of surgery, and during follow-up visit 1 week later
Measured: This will be assessed from the first day patients take the drugs until 1 weeks post-op.
Stone-free status
Stone free status as determined by low dose stone protocol CT scan per usual post-operative follow-up.
Measured: This will be assessed immediately post-op as well as 3 months post-op.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted26 Jul 2017
- Study start7 Jun 2017
- Primary completion24 Mar 2022
- Study completion24 Mar 2022
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (24)Papers the sponsor has linked to this study.
- Other trials for NephrolithiasisStudies of the same condition, open and under way.
- More trials run by University of California, IrvineThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Factorial
- Model description
- Patients will be randomized into 1 of 4 groups: Flomax + Placebo, Cialis + Placebo, Cialis + Flomax, Placebo + Placebo.
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Investigator
- Enrolment
- 220 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of California, Irvine
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Jaime Landman, University of California, Irvine
- Investigators
- Jaime Landman, MD, Principal investigator, UC Irvin Health
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03229889
- Sponsor's protocol ID
- 20163281
- Status last verified
- Aug 2024
- First submitted
- 26 Jun 2017
- Last updated
- 17 Feb 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Publications
Lusch A, Okhunov Z, del Junco M, Yoon R, Khanipour R, Menhadji A, Landman J. Comparison of optics and performance of single channel and a novel dual-channel fiberoptic ureteroscope. Urology. 2015 Jan;85(1):268-72. doi: 10.1016/j.urology.2014.09.032.
PubMed 25530400Landman J, Venkatesh R, Ragab M, Rehman J, Lee DI, Morrissey KG, Monga M, Sundaram CP. Comparison of intrarenal pressure and irrigant flow during percutaneous nephroscopy with an indwelling ureteral catheter, ureteral occlusion balloon, and ureteral access sheath. Urology. 2002 Oct;60(4):584-7. doi: 10.1016/s0090-4295(02)01861-7.
PubMed 12385911Takayasu H, Aso Y. Recent development for pyeloureteroscopy: guide tube method for its introduction into the ureter. J Urol. 1974 Aug;112(2):176-8. doi: 10.1016/s0022-5347(17)59675-5. No abstract available.
PubMed 4843325Monga M, Bhayani S, Landman J, Conradie M, Sundaram CP, Clayman RV. Ureteral access for upper urinary tract disease: the access sheath. J Endourol. 2001 Oct;15(8):831-4. doi: 10.1089/089277901753205843.
PubMed 11724124Kaplan AG, Lipkin ME, Scales CD Jr, Preminger GM. Use of ureteral access sheaths in ureteroscopy. Nat Rev Urol. 2016 Mar;13(3):135-40. doi: 10.1038/nrurol.2015.271. Epub 2015 Nov 24.
PubMed 26597613L'esperance JO, Ekeruo WO, Scales CD Jr, Marguet CG, Springhart WP, Maloney ME, Albala DM, Preminger GM. Effect of ureteral access sheath on stone-free rates in patients undergoing ureteroscopic management of renal calculi. Urology. 2005 Aug;66(2):252-5. doi: 10.1016/j.urology.2005.03.019.
PubMed 16040093Pietrow PK, Auge BK, Delvecchio FC, Silverstein AD, Weizer AZ, Albala DM, Preminger GM. Techniques to maximize flexible ureteroscope longevity. Urology. 2002 Nov;60(5):784-8. doi: 10.1016/s0090-4295(02)01948-9.
PubMed 12429296Traxer O, Thomas A. Prospective evaluation and classification of ureteral wall injuries resulting from insertion of a ureteral access sheath during retrograde intrarenal surgery. J Urol. 2013 Feb;189(2):580-4. doi: 10.1016/j.juro.2012.08.197. Epub 2012 Oct 8.
PubMed 22982421Traxer O, Wendt-Nordahl G, Sodha H, Rassweiler J, Meretyk S, Tefekli A, Coz F, de la Rosette JJ. Differences in renal stone treatment and outcomes for patients treated either with or without the support of a ureteral access sheath: The Clinical Research Office of the Endourological Society Ureteroscopy Global Study. World J Urol. 2015 Dec;33(12):2137-44. doi: 10.1007/s00345-015-1582-8. Epub 2015 May 14.
PubMed 25971204Delvecchio FC, Auge BK, Brizuela RM, Weizer AZ, Silverstein AD, Lallas CD, Pietrow PK, Albala DM, Preminger GM. Assessment of stricture formation with the ureteral access sheath. Urology. 2003 Mar;61(3):518-22; discussion 522. doi: 10.1016/s0090-4295(02)02433-0.
PubMed 12639636Lallas CD, Auge BK, Raj GV, Santa-Cruz R, Madden JF, Preminger GM. Laser Doppler flowmetric determination of ureteral blood flow after ureteral access sheath placement. J Endourol. 2002 Oct;16(8):583-90. doi: 10.1089/089277902320913288.
PubMed 12470467Miernik A, Wilhelm K, Ardelt PU, Adams F, Kuehhas FE, Schoenthaler M. Standardized flexible ureteroscopic technique to improve stone-free rates. Urology. 2012 Dec;80(6):1198-202. doi: 10.1016/j.urology.2012.08.042.
PubMed 23206763Hollingsworth JM, Rogers MA, Kaufman SR, Bradford TJ, Saint S, Wei JT, Hollenbeck BK. Medical therapy to facilitate urinary stone passage: a meta-analysis. Lancet. 2006 Sep 30;368(9542):1171-9. doi: 10.1016/S0140-6736(06)69474-9.
PubMed 17011944Edyvane KA, Trussell DC, Jonavicius J, Henwood A, Marshall VR. Presence and regional variation in peptide-containing nerves in the human ureter. J Auton Nerv Syst. 1992 Jun 15;39(2):127-37. doi: 10.1016/0165-1838(92)90053-j.
PubMed 1385511Itoh Y, Kojima Y, Yasui T, Tozawa K, Sasaki S, Kohri K. Examination of alpha 1 adrenoceptor subtypes in the human ureter. Int J Urol. 2007 Aug;14(8):749-53. doi: 10.1111/j.1442-2042.2007.01812.x.
PubMed 17681068
Study at a glance
From the registry record, last updated by the sponsor on 17 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Medication Facilitated Ureteral Access Sheath Deployment During Ureteroscopy and Endoscopic-Guided Percutaneous Nephrolithotomy: A Randomized Double-Blind Placebo Controlled Trial of Tadalafil, Tamsulosin and Combination
- ClinicalTrials.gov ID
- NCT03229889
- Acronym / sponsor ID
- 20163281
- Conditions
- Nephrolithiasis
- Keywords
- Access Sheath, PCNL, Percutaneous Nephrolithotomy, Ureteroscopy, Alpha Blocker, Flomax, PDE-5 Inhibitor, Cialis
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 220 participants (actual)
- Lead sponsor
- University of California, IrvineUniversity, hospital or other
- Study start
- 7 Jun 2017 (actual)
- Primary completion
- 24 Mar 2022 (actual)
- Study completion
- 24 Mar 2022 (actual)
- First posted
- 26 Jul 2017 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Extensive literature exists on the use of alpha-blocker medications for the removal of kidney stones. Alpha blockers relax certain muscles and help small blood vessels remain open. They work by keeping the hormone norepinephrine (noradrenaline) from tightening the muscles in the walls of smaller arteries and veins, which causes the vessels to remain open and relaxed. This improves blood flow and lowers blood pressure. There are studies that demonstrate alpha-blockers decrease ureteral pressure and help the ureter "relax."
Recent studies have shown that phosphodiesterase inhibitors may also help with ureteral stone passing. A phosphodiesterase inhibitor is a drug that blocks an enzyme that inhibits relaxation of smooth muscle. This means that it can help smooth muscle, such as the muscle that lines the ureter, to relax. While ureteral relaxation is helpful in the passage of ureteral stones, our study seeks to use this finding by pretreating participants with an older generation alpha blocker or a phosphodiesterase inhibitor prior to passage of a ureteral access sheath in cases in which ureteroscopy is being used to approach a ureteral or renal stone.
By relaxing the ureter, it is possible that a larger access sheath can be safely placed. This may allow for facilitating passage of the ureteroscope and extraction of stone fragments while precluding the development of potentially damaging intrarenal pressure from the flow of irrigant. The ureteral access sheath also protects the ureter from damage during the procedure. Placement of the largest access sheath possible is helpful in that larger stone fragments can be retrieved, the flow of irrigant is improved, and the surgical field is kept clear of blood or debris. To date, nobody has studied whether use of an uro-selective alpha blocker, alone, or in combination with a 5 phosphodiesterase inhibitor will result in passage of larger access sheaths.
In this study participants will be randomized into 1 of 4 categories: Flomax (alpha-blocker), Cialis (5-phosphodiesterase inhibitor), a combination of the 2, or a placebo arm. In this study the placebo, or no active drug, is the current standard of care and will serve as a control from the other 3 groups.
Detailed description
Technological improvements such as the miniaturization and development dual lumen ureteroscopes have improved the urologists' ability to treat urolithiasis1. The quality of flexible ureterorenoscopy is dependent on adequate visualization of the upper urinary tract. Adequate irrigation and visualization are compromised by debris from stone fragmentation and/or any bleeding during treatment. Fortunately, use of an ureteral access sheath (UAS) increases irrigant flow and reduces intrarenal pressure 2.
Ureteral access sheath technology was significantly improved by a member of our investigative team (RVC) thereby making it more widely acceptable3-5. The design changes allowed for easier deployment of the access sheath and the newer design was made to be kink resistant. This iteration of the device is easily deployed over a guidewire and has varying lengths such that it can be passed to the level of the stone in each case. Today's ureteral access sheaths range in size from 11-French to 16-French in diameter. The use of a ureteral access sheath has been shown to decrease intraoperative time, provide higher stone free rates, incur less cost due to shorter operating room times, and lead to fewer secondary procedures5,6. The access sheath should also, in theory, lower the risk of urinary tract infection due to decreased intrarenal pressure thereby resulting in less pyelovenous and less pyelolymphatic backflow. Lastly, use of an access sheath minimizes damage to the fragile flexible ureteroscope and thus increases their longevity while decreasing repair costs7.
Despite the above findings use of the UAS has not been universally embraced. A single study by Traxer et al., showed the incidence of low grade ureteric injury using UAS was 46% and that with serious injuries (i.e. urothelial tears) occurred in 13%8. However, a follow-up study by the same group showed no evidence of delayed long-term ureteral stricture formation; in fact, the patients who had a ureteral access sheath deployed there was a lower risk of post-operative complications9. Further, other studies have shown that the rate of ureteral stricture formation following use of a ureteral access sheath is 1.4% compared to a baseline rate of 1-3% during routine ureteroscopy without an access sheath10. In the afore cited study, the solitary occurrence of a post-ureteral access sheath ureteral stricture occurred at the ureteropelvic junction in a patient who underwent four endoscopic procedures for struvite stones; in all four surgeries, the access sheath was deployed at the level of iliac vessels well below the site of the patient's stricture10. Of note, porcine models have shown decrease ureteral blood flow following the acute deployment of a large access sheath, however over time the flow normalized and in follow-up there was no increase in post procedural ureteral stricture formation11.
Most urologists who place a ureteral access sheath do so without any pretreatment for ureteral relaxation. At our institution, the investigators routinely use alpha blockers (tamsulosin) as an adjunctive medical therapy to possibly relax the ureteral muscle; the medication is begun one week prior to surgery as it takes five days for the medicine to reach a steady state. It has been the investigator's experience that they are able to place larger ureteral access sheaths (i.e. 14 and 16 French size) with this approach. Additionally, examination of the ureter at the end of the procedure has shown minimal effect from placement of the access sheath; to date, the study team has not had any patient return with a post procedural ureteral stricture. Of note, it is the investigator's practice that if there is any resistance to deployment of the ureteral access sheath, then a smaller sized sheath is used; should the smaller sheath encounter resistance to its passage then a ureteral stent is placed and the procedure is postponed for a week. Stent placement in a ureter facilitates subsequent placement of an access sheath8,12.
An extensive literature exists on the role of alpha-blocker medications on the relaxation of ureteral smooth muscle13. This is due to the numerous alpha-1 receptors along the ureter, particularly in the distal ureter14,15. This knowledge originally led to the development of medical expulsive therapy in the treatment of ureteral stones. Several meta-analyses have shown that alpha blockers help passage of distal ureteral stones in the 5-10mm range, in less time and with less pain. The most extensively studied medication in this regard has been tamsulosin In addition to alpha blockade, recent in vitro studies have shown that phosphodiesterase-5 (PDE-5) inhibitors such as a tadalafil, commonly known by its tradename Cialis, also facilitate ureteral relaxation18-20. This has been substantiated by clinical studies which showed that sildenafil compared to placebo improved stone passage by 27%21. Further when tadalafil was added to tamsulosin the result was improved stone passage; the combined medications were well tolerated22,23.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Factorial
- Masking
- Triple blind (participant, care provider, investigator)
- Number of arms
- 4
- Model description
- Patients will be randomized into 1 of 4 groups: Flomax + Placebo, Cialis + Placebo, Cialis + Flomax, Placebo + Placebo.
| Arm | Type | Receives |
|---|---|---|
| Flomax + Placebo | Active comparator | Drug: Flomax 0.4Mg CapsulePatients will be prescribed Flomax 0.4Mg Capsule and given a bottle of placebo. They will be instructed to take 1 of each pill for the seven days prior to their surgery. |
| Cialis + Placebo | Active comparator | Drug: Cialis 5Mg TabletPatients will be prescribed Cialis 5Mg tablet and given a bottle of placebo. They will be instructed to take 1 of each pill for the seven days prior to their surgery. |
| Cialis + Flomax | Active comparator | Combination Product: Cialis + FlomaxPatients will be prescribed .4mg of Flomax and 5mg of Cialis. They will be instructed to take 1 of each pill for the seven days prior to their surgery. |
| Placebo + Placebo | Placebo comparator | Drug: PlaceboGiven 2 bottles of placebo. They will be instructed to take 1 of each pill for the seven days prior to their surgery. |
Who may qualify
- Ages
- 18 to 99 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Patients undergoing percutaneous nephrolithotomy (PCNL) or ureteroscopy (URS) for renal or proximal ureteral urolithiasis
- A documented sterile urine culture within 1-2 weeks of the procedure
- ≥ 18 years old
- Ability to understand and the willingness to sign a written informed consent
Key exclusion criteria (18 listed)
- Patients < 18-years-old
- Presence of ureteral stent or nephrostomy tube prior to scheduled procedure
- Patients requiring open, endoscopic, or laparoscopic procedure in the same setting as the intended URS or PCNL
- Planned concurrent bilateral endoscopic ureteral procedures
- Patients currently taking alpha-blockers within 14 days of surgery
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Cialis 5Mg TabletAlso: TadalafilCialis is a PDE-5 inhibitor that has been shown to relax smooth muscle. Patients will be asked to 1 pill for 7 days prior to surgery. | Drug | Cialis + Placebo |
| Flomax 0.4Mg CapsuleAlso: TamsulosinTamsulosin is an alpha-blocker that has been shown to relax smooth muscle in the genitourinary system. Patients will be asked to 1 pill for 7 days prior to surgery. | Drug | Flomax + Placebo |
| Cialis + FlomaxAlso: Tamsulsoin, TadalafilCialis is a PDE-5 inhibitor that has been shown to relax smooth muscle. Tamsulosin is an alpha-blocker that has been shown to relax smooth muscle in the genitourinary system. A combination of these two drugs may increase the relaxation effects in the ureter. Patients will be asked to 1 of each pill for 7 days prior to surgery. | Combination product | Cialis + Flomax |
| PlaceboAlso: Inactive DrugThis is plant cell based pill that contains no active ingredient. Patients will be asked to 1 pill for 7 days prior to surgery. | Drug | Placebo + Placebo |
Primary outcome
Passage of 16F Access Sheath
Time frame: This will be assessed immediately post-op per patient.
Our primary objective is to assess the ability of a uroselective alpha-blocker (tamsulosin) and PDE-5 inhibitor (tadalafil), either alone or in combination will facilitate the passage of a 16F ureteral access sheath. Successful deployment will be defined as passage of the 16F ureteral access sheath into the proximal ureter or ureteropelvic junction. Difficulty in passing a 16F ureteral access sheath will be defined as a "failure". In this situation, we will place smaller ureteral access sheath (i.e. 11F or 14F), or opt to place a stent to dilate the ureter, and plan for surgery in the future; this is standard of care.
4 secondary outcomes
Injury
Time frame: This will be assessed immediately post-op per patient.
Complications
Time frame: This will be assessed post-op per patient.
Adverse events
Time frame: This will be assessed from the first day patients take the drugs until 1 weeks post-op.
Stone-free status
Time frame: This will be assessed immediately post-op as well as 3 months post-op.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 17 Feb 2026.
- Background: PubMed 25530400Lusch A, Okhunov Z, del Junco M, Yoon R, Khanipour R, Menhadji A, Landman J. Comparison of optics and performance of single channel and a novel dual-channel fiberoptic ureteroscope. Urology. 2015 Jan;85(1):268-72. doi: 10.1016/j.urology.2014.09.032.
- Background: PubMed 12385911Landman J, Venkatesh R, Ragab M, Rehman J, Lee DI, Morrissey KG, Monga M, Sundaram CP. Comparison of intrarenal pressure and irrigant flow during percutaneous nephroscopy with an indwelling ureteral catheter, ureteral occlusion balloon, and ureteral access sheath. Urology. 2002 Oct;60(4):584-7. doi: 10.1016/s0090-4295(02)01861-7.
- Background: PubMed 4843325Takayasu H, Aso Y. Recent development for pyeloureteroscopy: guide tube method for its introduction into the ureter. J Urol. 1974 Aug;112(2):176-8. doi: 10.1016/s0022-5347(17)59675-5. No abstract available.
- Background: PubMed 11724124Monga M, Bhayani S, Landman J, Conradie M, Sundaram CP, Clayman RV. Ureteral access for upper urinary tract disease: the access sheath. J Endourol. 2001 Oct;15(8):831-4. doi: 10.1089/089277901753205843.
- Background: PubMed 26597613Kaplan AG, Lipkin ME, Scales CD Jr, Preminger GM. Use of ureteral access sheaths in ureteroscopy. Nat Rev Urol. 2016 Mar;13(3):135-40. doi: 10.1038/nrurol.2015.271. Epub 2015 Nov 24.
- Background: PubMed 16040093L'esperance JO, Ekeruo WO, Scales CD Jr, Marguet CG, Springhart WP, Maloney ME, Albala DM, Preminger GM. Effect of ureteral access sheath on stone-free rates in patients undergoing ureteroscopic management of renal calculi. Urology. 2005 Aug;66(2):252-5. doi: 10.1016/j.urology.2005.03.019.
- Background: PubMed 12429296Pietrow PK, Auge BK, Delvecchio FC, Silverstein AD, Weizer AZ, Albala DM, Preminger GM. Techniques to maximize flexible ureteroscope longevity. Urology. 2002 Nov;60(5):784-8. doi: 10.1016/s0090-4295(02)01948-9.
- Background: PubMed 22982421Traxer O, Thomas A. Prospective evaluation and classification of ureteral wall injuries resulting from insertion of a ureteral access sheath during retrograde intrarenal surgery. J Urol. 2013 Feb;189(2):580-4. doi: 10.1016/j.juro.2012.08.197. Epub 2012 Oct 8.
- Background: PubMed 25971204Traxer O, Wendt-Nordahl G, Sodha H, Rassweiler J, Meretyk S, Tefekli A, Coz F, de la Rosette JJ. Differences in renal stone treatment and outcomes for patients treated either with or without the support of a ureteral access sheath: The Clinical Research Office of the Endourological Society Ureteroscopy Global Study. World J Urol. 2015 Dec;33(12):2137-44. doi: 10.1007/s00345-015-1582-8. Epub 2015 May 14.
- Background: PubMed 12639636Delvecchio FC, Auge BK, Brizuela RM, Weizer AZ, Silverstein AD, Lallas CD, Pietrow PK, Albala DM, Preminger GM. Assessment of stricture formation with the ureteral access sheath. Urology. 2003 Mar;61(3):518-22; discussion 522. doi: 10.1016/s0090-4295(02)02433-0.
- Background: PubMed 12470467Lallas CD, Auge BK, Raj GV, Santa-Cruz R, Madden JF, Preminger GM. Laser Doppler flowmetric determination of ureteral blood flow after ureteral access sheath placement. J Endourol. 2002 Oct;16(8):583-90. doi: 10.1089/089277902320913288.
- Background: PubMed 23206763Miernik A, Wilhelm K, Ardelt PU, Adams F, Kuehhas FE, Schoenthaler M. Standardized flexible ureteroscopic technique to improve stone-free rates. Urology. 2012 Dec;80(6):1198-202. doi: 10.1016/j.urology.2012.08.042.
- Individual participant dataSharing planned: Undecided
Related trials for Nephrolithiasis
Not yet recruiting
Automated Versus Manual Irrigation During Flexible Ureteroscopy
Renal Stone Disease
Not yet recruiting
Optimal Intrarenal Pressure During Flexible Ureteroscopy
Renal Stone Disease
RecruitingObservational study
Stone Clearance With Aspiration vs Other Technologies: a Real-world Evidence Study
Urolithiasis, Stones, Kidney
Not yet recruiting
Intertransverse Process Block Versus Erector Spinae Plane Block for Postoperative Analgesia After Percutaneous Nephrolithotomy
Kidney Stones, Urolithiasis, Hypocitraturia, Pain, Postoperative
Not yet recruiting
Comparison of Smart Pressure-Controlled Flexible Ureteroscopy and Flexible Suction Ureteral Access Sheath-Assisted Flexible Ureteroscopy for 2-3 cm Renal Stones
Kidney Stones
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Jaime Landman, MD principal investigator
UC Irvin Health
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Cialis 5Mg Tablet, Flomax 0.4Mg Capsule and Cialis + Flomax in people with Nephrolithiasis, run by University of California, Irvine at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 18 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 17 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Passage of 16F Access Sheath (time frame: This will be assessed immediately post-op per patient.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT03229889, which also lists 24 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 17 Feb 2026.