Mini-PNCL vs fURS in Management of Nephrolithiasis

Ambulatory Tubeless Mini Percutaneous Nephrolithotomy Versus Retrograde Intrarenal Surgery in the Management of Nephrolithiasis: A Randomized Controlled Clinical Study

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.

Study Overview

• Status: Recruiting
• Conditions: Nephrolithiasis; Kidney Stone
• Intervention / Treatment: Procedure: Flexible ureteroscopy; Procedure: Mini-percutaneous nephrolithotomy

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?

• Study Type: Interventional
• Enrollment (Estimated): 72
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Imran Malik, MSc; Phone Number: 6608 (807) 684-6000; Email: maliki@tbh.net
• Study Contact Backup: Name: Shalyn Littlefield, MSc; Phone Number: 6608 (807) 684-6000; Email: littlefs@tbh.net

Study Locations

• Canada
  • Ontario
    • Thunder Bay, Ontario, Canada, P7B6V4
      • Recruiting
      • Thunder Bay Regional Health Sciences Centre/Thunder Bay Regional Health Research Institute
      • Contact: Imran Malik, MSc; Phone Number: 6608 (807) 684-6000; Email: maliki@tbh.net
      • Contact: Shalyn Littlefield, MSc; Phone Number: 6608 (807) 684-6000; Email: littlefs@tbh.net
      • Principal Investigator: Hazem Elmansy, MD
      • Sub-Investigator: Walid Shahrour, MD
      • Sub-Investigator: Ahmed Kotb, MD
      • Sub-Investigator: Owen Prowse, MD
      • Sub-Investigator: Fabiola Oquendo, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

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:

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.

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
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; 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.
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; 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).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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	1-day
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	4-weeks post-op

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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	4 weeks
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.	1-day post-op
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.	4-weeks post-op
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".	1-day post-op
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".	4-weeks post-op

Collaborators and Investigators

• Sponsor: Thunder Bay Regional Health Research Institute
• Investigators: Principal Investigator: Hazem Elmansy, MD, Thunder Bay Regional Health Sciences Centre

Study record dates

Study Major Dates

• Study Start (Actual): October 5, 2020
• Primary Completion (Estimated): July 1, 2025
• Study Completion (Estimated): December 31, 2025

Study Registration Dates

• First Submitted: May 5, 2020
• First Submitted That Met QC Criteria: May 11, 2020
• First Posted (Actual): May 15, 2020

Study Record Updates

• Last Update Posted (Actual): November 18, 2023
• Last Update Submitted That Met QC Criteria: November 16, 2023
• Last Verified: November 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Kidney Diseases; Urologic Diseases; Pathological Conditions, Anatomical; Urolithiasis; Urinary Calculi; Calculi; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Male Urogenital Diseases; Kidney Calculi; Nephrolithiasis
• Other Study ID Numbers: RP-645

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: 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.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No