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CompletedNCT04389853Updated Aug 16, 2024

Mini-PNCL vs fURS in Management of Nephrolithiasis

An interventional study of Flexible ureteroscopy and Mini-percutaneous nephrolithotomy in Nephrolithiasis and Kidney Stone, sponsored by Thunder Bay Regional Health Research Institute. Completed at 1 site in Canada. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2024-08-16.

Sponsored by Thunder Bay Regional Health Research Institute · Not applicable, Interventional, and Treatment

Phase
Not applicable
Study type
Interventional
Enrollment
76
Allocation
Randomized
Ages
18 Years and older
Sex
All
01

Study summary

The prevalence of nephrolithiasis is increasing over the last two decades, and kidney stones is a recurrent disorder, with lifetime recurrence risks reported to be as high as 50%. One of the most challenging stones is the lower pole (LP) nephrolithiasis.

The standard management of lower pole stones (LPS), is still controversial especially for stones smaller than 20 mm, with retrograde intrarenal surgery (RIRS) and mini-PCNL (miniperc) both demonstrated to be safe and effective methods for treating LPS with a diameter of 1-2 cm.

Selecting the optimal modality for treating renal calculi is challenging, as both techniques may be associated with different patient benefits and risk profiles. Despite the evolution of mini-PCNL and fURS techniques into clinical practice, there is a lack of comparative clinical data assessing SFRs and complication rates.

To the investigators' knowledge, no previous studies have addressed the outcome of ambulatory tubeless miniperc as a same day procedure, which this study will look to assess. The investigators are planning to discharge all participants home the night of surgery, without admission or insertion of nephrostomy tube. This will decrease the morbidity of miniperc and encourage head-to-head comparison with fURS in a prospective randomized protocol.

Read the detailed description

The prevalence of nephrolithiasis is increasing over the last two decades, and kidney stones is a recurrent disorder, with lifetime recurrence risks reported to be as high as 50%. One of the most challenging stones is the lower pole (LP) nephrolithiasis. This could be explained by its antigravity location, acute angle with the renal pelvis and the narrow angle of the infundibulum. Therefore, the optimal management of LP calculi continues to be a dilemma. The standard management of lower pole stones (LPS), is still controversial especially for stones smaller than 20 mm, with competing interventions possessing advantages and disadvantages. Treatment options include percutaneous nephrolithotomy (PCNL), retrograde intrarenal surgery (RIRS), or shockwave lithotripsy (SWL).

PCNL has regained popularity thanks to the possibility of using reduced calibers and modern technology, which has reduced the complications without compromising the stone clearance, and more efficient intracorporeal lithotripter modalities. However, PCNL is still a challenging surgical technique and can be associated with significant complications that may compromise its efficacy. In the present time, surgeons have available calibers ranging from 4.8 to 30 French. Many reports advocate that morbidity after PCNL may be reduced by recent modifications, such as mini-PCNL (miniperc). One meta-analysis of mini-PCNL and conventional PCNL demonstrated that mini-PCNL had a greater safety profile with similar stone free rates (SFRs).

Another alternative option is RIRS. RIRS has gained much popularity especially when the role of SWL, in management of LPS, has been significantly diminished in the few last years. RIRS is dependent mainly on flexible ureteroscopy (fURS). fURS increases the quality and performance of upper urinary tract exploration, allowing for the treatment of the majority of stones at all sites. Moreover, it is associated with no risk of renal parenchymal injuries and a very low risk of bleeding.

RIRS and miniperc are both safe and effective methods for treating LPS with a diameter of 1-2 cm. The SFRs were comparable at the first postoperative day (90.2% vs. 93.2%) and the second month postoperatively (93.8% vs. 95.1%), for RIRS and miniperc, respectively. However, miniperc was associated with significant longer hospital stay and higher hospitalization costs.

Therefore, selecting the optimal modality for treating renal calculi is challenging, as both techniques may be associated with different patient benefits and risk profiles. Despite the evolution of mini-PCNL and fURS techniques into clinical practice, there is a lack of comparative clinical data assessing SFRs and complication rates.

To the investigators' knowledge, no previous studies have addressed the outcome of ambulatory tubeless miniperc as a same day procedure, which this study will look to assess. The investigators are planning to discharge all participants home the night of surgery, without admission or insertion of nephrostomy tube. This should decrease the morbidity of miniperc and encourage head-to-head comparison with fURS in a prospective randomized protocol.

The investigators will attempt to address whether there is a difference in clinical outcome between ambulatory mini percutaneous nephrolithotomy and flexible ureteroscopy in the management of lower pole kidney stones?

02

Conditions studied

  • Nephrolithiasis
  • Kidney Stone
03

In context

Kidney Calculi

598 studies on the registry are indexed under Kidney Calculi; 163 are open to participants now.

This study's enrollment of 76 is below the median of 90 across 461 interventional studies indexed under Kidney Calculi.

Browse Kidney Calculi studies →

Lead sponsor

Thunder Bay Regional Health Research Institute is the lead sponsor of 10 studies on the registry; 2 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Inclusion criteria

  1. Male and female subjects over 18 years of age at the time of enrollment.
  2. Patients referred with single kidney stones of 10-20 mm in its largest diameter, or multiple stones involving a single calyx.
  3. Written informed consent to participate in the study
  4. Ability to comply with the requirements of the study procedures

Exclusion criteria

Exclusion Criteria:

  1. Congenital anatomic anomalies of the kidney, ureters or bladder.
  2. Previous ipsilateral renal surgery within past five years.
  3. Patients with ipsilateral distal ureteral stones or stricture.
  4. Stone size > 20 mL or multiple kidney stones in different calyces.
  5. Previous SWL treatment for the same stone.
  6. Patients presented with a previously inserted ipsilateral ureteral stent.
  7. Participants with active urinary tract infection until appropriately treated
  8. Uncorrected coagulopathy (anticoagulants or blood thinners which cannot be withheld before surgery).
  9. Pregnancy or morbid obesity
  10. Participants with preexisting conditions, which, in the opinion of the investigator, interfere with the conduct of the study.
  11. Participants who are uncooperative or cannot follow instructions.
  12. Participants who lack the capacity to provide free and informed written consent.
  13. Patients with solitary kidney.
05

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Single (Outcomes assessor)
Enrollment
76 participants (actual)

Study arms

  • Active comparator
    Flexible ureteroscopy (fURS)

    Retrograde intrarenal surgery (RIRS) has gained much popularity especially when the role of SWL, in management of LPS, has been significantly diminished in the few last years5. RIRS is dependent mainly on flexible ureteroscopy (fURS). fURS increases the quality and performance of upper urinary tract exploration, allowing for the treatment of the majority of stones at all sites. Moreover, it is associated with no risk of renal parenchymal injuries and a very low risk of bleeding.

    Procedure: Flexible ureteroscopy

  • Active comparator
    Mini-percutaneous nephrolithotomy (mini-PCNL)

    PCNL has regained popularity thanks to the possibility of using reduced calibers and modern technology, which has reduced the complications without compromising the stone clearance, and more efficient intracorporeal lithotripter modalities. However, PCNL is still a challenging surgical technique and can be associated with significant complications that may compromise its efficacy. In the present time, we have available calibers ranging from 4.8 to 30 French. Many reports advocate that morbidity after PCNL may be reduced by recent modifications, such as mini-PCNL (miniperc). One meta-analysis of mini-PCNL and conventional PCNL demonstrated that mini-PCNL had a greater safety profile with similar stone free rates (SFRs)4

    Procedure: Mini-percutaneous nephrolithotomy

Interventions

  • ProcedureFlexible ureteroscopy

    Retograde intrarenal surgery (RIRS) has gained much popularity especially when the role of SWL, in management of LPS, has been significantly diminished in the few last years5. RIRS is dependent mainly on flexible ureteroscopy (fURS). fURS increases the quality and performance of upper urinary tract exploration, allowing for the treatment of the majority of stones at all sites. Moreover, it is associated with no risk of renal parenchymal injuries and a very low risk of bleeding.

  • ProcedureMini-percutaneous nephrolithotomy

    PCNL has regained popularity thanks to the possibility of using reduced calibers and modern technology, which has reduced the complications without compromising the stone clearance, and more efficient intracorporeal lithotripter modalities. However, PCNL is still a challenging surgical technique and can be associated with significant complications that may compromise its efficacy. In the present time, we have available calibers ranging from 4.8 to 30 French. Many reports advocate that morbidity after PCNL may be reduced by recent modifications, such as mini-PCNL (miniperc). One meta-analysis of mini-PCNL and conventional PCNL demonstrated that mini-PCNL had a greater safety profile with similar stone free rates (SFRs).

06

What researchers measure

Primary outcomes

  1. Stone-free status

    Operation success will be evaluated with a non-contrast computed tomography (CT) scan on the first post-operative day, as per standard of care. Presence or absence of kidney stones will be confirmed via CT scan

    Time frame: 1-day

  2. Stone-free status

    Operation success will be re-evaluated with a non-contrast computed tomography (CT) scan at 4-weeks post-operation, as per standard of care. Presence or absence of kidney stones will be confirmed via CT scan

    Time frame: 4-weeks post-op

Secondary outcomes

  1. To compare safety measures

    Adverse events including perioperative bleeding, operative time, fluoroscopy time, need for blood transfusion, stone composition, fragmentation type, ureteral stenting, and urinary tract infection will be recorded intra and post-op

    Time frame: 4 weeks

  2. To compare stone free status of single use vs reusable fURS

    Subgroup analysis comparing two types of fURS treatments. In this study, participants randomized to the fURS cohort may receive either single use or reusable fURS are their standard of care treatment. The investigators plan to conduct a subgroup analysis comparing stone-free status 1-day post-op using a standard of care non-contrast CT scan.

    Time frame: 1-day post-op

  3. To compare stone free status of single use vs reusable fURS

    Subgroup analysis comparing two types of fURS treatments. In this study, participants randomized to the fURS cohort may receive either single use or reusable fURS are their standard of care treatment. The investigators plan to conduct a subgroup analysis comparing stone-free status 4-weeks post-op using a standard of care non-contrast CT scan.

    Time frame: 4-weeks post-op

  4. Assess the postoperative pain between both techniques

    Post-surgical pain will be assessed using a Visual Analog Scale (VAS) questionnaire. This questionnaire consists of 1 question asking participants to choose a number from 0-10 describing their pain at the current moment. A lower score indicates less pain, while a higher score indicates a higher degree of pain. For example a score of 0 indicates "No Pain", while a score of 10 indicates "Unbearable Pain".

    Time frame: 1-day post-op

  5. Assess the postoperative pain between both techniques

    Post-surgical pain will be assessed using a Visual Analog Scale (VAS) questionnaire. This questionnaire consists of 1 question asking participants to choose a number from 0-10 describing their pain at the current moment. A lower score indicates less pain, while a higher score indicates a higher degree of pain. For example a score of 0 indicates "No Pain", while a score of 10 indicates "Unbearable Pain".

    Time frame: 4-weeks post-op

07

Study locations

1 site
  • Thunder Bay Regional Health Sciences Centre/Thunder Bay Regional Health Research Institute
    Thunder Bay, Ontario P7B6V4, Canada
08

References and documents

Individual participant data

Plan to share: No — There are no plans to share participant data with other researchers. Findings may be presented locally, nationally, and internationally at conferences. Any data presented will be de-identified and grouped prior to use, as to protect participant confidentiality.

No publications or documents are linked to this record.

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Aug 16, 2024, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT04389853
Lead sponsor
Thunder Bay Regional Health Research Institute
Responsible party
Hazem Elmansy (Urology Surgeon, Thunder Bay Regional Health Research Institute) — Principal investigator
First posted
May 15, 2020
Start date
Oct 5, 2020
Primary completion
Apr 24, 2024
Completion
Apr 24, 2024
Last update
Aug 16, 2024

Study contacts

Hazem Elmansy, MD
principal investigator · Thunder Bay Regional Health Sciences Centre

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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