NephrolithiasisNCT07854743
Outcomes and Inter-Stage Interval in Staged Bilateral PCNL
An observational study of Nephrolithiasis, run by Ankara Training and Research Hospital at 1 site in Turkey (Türkiye).
Trial summary
This prospective, single-center observational study evaluated patients undergoing staged bilateral standard percutaneous nephrolithotomy (PCNL) for bilateral renal stones. Each participant underwent PCNL on one kidney followed by contralateral PCNL in a separate session, allowing a paired within-patient comparison in… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Nephrolithiasis
- How many people
- 34 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Feb 2022to 15 Sep 2026
- Phase
- Observational
- 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 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Adult patients with bilateral renal stones who underwent staged bilateral standard PCNL at Ankara Training and Research Hospital. Each participant underwent PCNL on one kidney followed by contralateral PCNL in a separate session, allowing paired within-patient assessment of the two procedures.
Who may be able to join
- Age ≥18 years.
- Bilateral renal stones requiring staged bilateral standard percutaneous nephrolithotomy (PCNL).
- Undergoing PCNL of one kidney followed by contralateral PCNL in a separate session.
Who cannot join
- Age <18 years.
- Positive preoperative urine culture.
- Use of preoperative antibiotics.
- Presence of an indwelling urinary drainage catheter before PCNL, including a urethral catheter, ureteral stent, or percutaneous nephrostomy.
- Previous renal surgery on the same kidney.
- Renal tumor.
Show all 9Show fewer
- Chronic renal failure.
- Congenital renal malformation.
- Chronic use of oral immunosuppressive agents.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Within-patient Comparison of First- Versus Second-side Outcomes and the Effect of the Inter-stage Interval in Staged Bilateral Percutaneous Nephrolithotomy: a Prospective Single-center Study
This prospective, single-center observational study evaluated patients undergoing staged bilateral standard percutaneous nephrolithotomy (PCNL) for bilateral renal stones. Each participant underwent PCNL on one kidney followed by contralateral PCNL in a separate session, allowing a paired within-patient comparison in which each patient served as their own control. The study aimed to compare operative, hematologic, renal, inflammatory, stone-free, and complication outcomes between the first and second PCNL procedures. In addition, the association between the inter-stage interval and second-side outcomes was explored, with particular emphasis on systemic inflammatory response assessed using neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII).
Read the detailed description
This prospective, single-center observational study was conducted in adult patients undergoing staged bilateral standard percutaneous nephrolithotomy (PCNL) for bilateral renal stone disease. Each participant underwent PCNL on one kidney followed by contralateral PCNL in a separate session. This design allowed paired within-patient comparison of the two procedures, with each participant serving as their own control. The kidney with the greater stone burden or more complex stone configuration was generally treated first. The inter-stage interval was determined according to clinical practice rather than by random assignment.
All PCNL procedures were performed under general anesthesia after confirmation of a sterile preoperative urine culture. Percutaneous access was obtained under fluoroscopic guidance, and a single tract was established using 26-30 Fr Amplatz sheaths. Nephroscopy was performed with a 24 Fr rigid nephroscope, and stones were fragmented using pneumatic lithotripsy. An antegrade ureteral stent and nephrostomy tube were routinely placed at the end of the procedure. The nephrostomy tube was generally removed between postoperative days 1 and 3. Postoperative laboratory testing and kidney-ureter-bladder radiography were obtained on postoperative day 1, and final stone-free status was assessed by non-contrast computed tomography at the third postoperative week.
Renal function was assessed using estimated glomerular filtration rate calculated with the 2021 CKD-EPI creatinine equation, and acute kidney injury was evaluated according to KDIGO criteria. Systemic inflammatory response was characterized using complete-blood-count-derived indices, including the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII), measured preoperatively and on postoperative day 1 for each procedure. Perioperative, hematologic, renal, inflammatory, stone-free, and complication outcomes were compared between the first and second PCNL sessions using a paired within-patient framework. The association between the inter-stage interval and second-side outcomes, particularly postoperative changes in inflammatory indices, was additionally explored.
- Conditions
- Nephrolithiasis
- Keywords
- Systemic Inflammatory Response Syndrome, Acute Kidney Injury, Inflammation, Nephrolithotomy, Percutaneous
- Medical subject headings
- Nephrolithiasis, Systemic Inflammatory Response Syndrome, Acute Kidney Injury, Inflammation
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Neutrophil-to-Lymphocyte Ratio (ΔNLR) After PCNL
The neutrophil-to-lymphocyte ratio (NLR) was calculated from absolute neutrophil and lymphocyte counts obtained preoperatively and on postoperative day 1 (POD1) for each PCNL session. ΔNLR was defined as POD1 NLR minus preoperative NLR. ΔNLR was compared between the first- and second-side PCNL procedures using a paired within-patient design.
Measured: From preoperative assessment to postoperative day 1 after each PCNL procedure
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Oct 2026
- Study start1 Feb 2022
- Primary completion21 Aug 2026
- Study completion15 Sep 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for NephrolithiasisStudies of the same condition, open and under way.
- 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
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 34 participants (actual)
Sponsor and investigators
- Lead sponsor
- Ankara Training and Research Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Arif Bedirhan Bayraktar, Ankara Training and Research Hospital
- Investigators
- Arif Bedirhan Bayraktar, Principal investigator, Ankara Training and Research Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07854743
- Sponsor's protocol ID
- PCNL2026
- Status last verified
- Oct 2026
- First submitted
- 27 Sep 2026
- Last updated
- 5 Oct 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 5 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Within-patient Comparison of First- Versus Second-side Outcomes and the Effect of the Inter-stage Interval in Staged Bilateral Percutaneous Nephrolithotomy: a Prospective Single-center Study
- ClinicalTrials.gov ID
- NCT07854743
- Acronym / sponsor ID
- PCNL2026
- Conditions
- Nephrolithiasis
- Keywords
- Systemic Inflammatory Response Syndrome, Acute Kidney Injury, Inflammation, Nephrolithotomy, Percutaneous
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 34 participants (actual)
- Lead sponsor
- Ankara Training and Research HospitalUniversity, hospital or other
- Study start
- 1 Feb 2022 (actual)
- Primary completion
- 21 Aug 2026 (actual)
- Study completion
- 15 Sep 2026 (actual)
- First posted
- 2 Oct 2026 (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.
This prospective, single-center observational study evaluated patients undergoing staged bilateral standard percutaneous nephrolithotomy (PCNL) for bilateral renal stones. Each participant underwent PCNL on one kidney followed by contralateral PCNL in a separate session, allowing a paired within-patient comparison in which each patient served as their own control. The study aimed to compare operative, hematologic, renal, inflammatory, stone-free, and complication outcomes between the first and second PCNL procedures. In addition, the association between the inter-stage interval and second-side outcomes was explored, with particular emphasis on systemic inflammatory response assessed using neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII).
Detailed description
This prospective, single-center observational study was conducted in adult patients undergoing staged bilateral standard percutaneous nephrolithotomy (PCNL) for bilateral renal stone disease. Each participant underwent PCNL on one kidney followed by contralateral PCNL in a separate session. This design allowed paired within-patient comparison of the two procedures, with each participant serving as their own control. The kidney with the greater stone burden or more complex stone configuration was generally treated first. The inter-stage interval was determined according to clinical practice rather than by random assignment.
All PCNL procedures were performed under general anesthesia after confirmation of a sterile preoperative urine culture. Percutaneous access was obtained under fluoroscopic guidance, and a single tract was established using 26-30 Fr Amplatz sheaths. Nephroscopy was performed with a 24 Fr rigid nephroscope, and stones were fragmented using pneumatic lithotripsy. An antegrade ureteral stent and nephrostomy tube were routinely placed at the end of the procedure. The nephrostomy tube was generally removed between postoperative days 1 and 3. Postoperative laboratory testing and kidney-ureter-bladder radiography were obtained on postoperative day 1, and final stone-free status was assessed by non-contrast computed tomography at the third postoperative week.
Renal function was assessed using estimated glomerular filtration rate calculated with the 2021 CKD-EPI creatinine equation, and acute kidney injury was evaluated according to KDIGO criteria. Systemic inflammatory response was characterized using complete-blood-count-derived indices, including the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII), measured preoperatively and on postoperative day 1 for each procedure. Perioperative, hematologic, renal, inflammatory, stone-free, and complication outcomes were compared between the first and second PCNL sessions using a paired within-patient framework. The association between the inter-stage interval and second-side outcomes, particularly postoperative changes in inflammatory indices, was additionally explored.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Adult patients with bilateral renal stones who underwent staged bilateral standard PCNL at Ankara Training and Research Hospital. Each participant underwent PCNL on one kidney followed by contralateral PCNL in a separate session, allowing paired within-patient assessment of the two procedures.
Key inclusion criteria (3 listed)
- Age ≥18 years.
- Bilateral renal stones requiring staged bilateral standard percutaneous nephrolithotomy (PCNL).
- Undergoing PCNL of one kidney followed by contralateral PCNL in a separate session.
Key exclusion criteria (9 listed)
- Age <18 years.
- Positive preoperative urine culture.
- Use of preoperative antibiotics.
- Presence of an indwelling urinary drainage catheter before PCNL, including a urethral catheter, ureteral stent, or percutaneous nephrostomy.
- Previous renal surgery on the same kidney.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Change in Neutrophil-to-Lymphocyte Ratio (ΔNLR) After PCNL
Time frame: From preoperative assessment to postoperative day 1 after each PCNL procedure
The neutrophil-to-lymphocyte ratio (NLR) was calculated from absolute neutrophil and lymphocyte counts obtained preoperatively and on postoperative day 1 (POD1) for each PCNL session. ΔNLR was defined as POD1 NLR minus preoperative NLR. ΔNLR was compared between the first- and second-side PCNL procedures using a paired within-patient design.
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 5 Oct 2026.
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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.
Arif Bedirhan Bayraktar principal investigator
Ankara Training and Research Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Nephrolithiasis, run by Ankara Training and Research Hospital at 1 site in Turkey (Türkiye).
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 3 inclusion and 9 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 5 Oct 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 Turkey (Türkiye). 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. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
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?
Change in Neutrophil-to-Lymphocyte Ratio (ΔNLR) After PCNL (time frame: From preoperative assessment to postoperative day 1 after each PCNL procedure). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 5 Oct 2026; AzTrials last refreshed its copy on 26 Oct 2026.