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NCT Number: NCT07535281

Effect of Complete Suction-Induced Collapse of the Renal Collecting System at the End of RIRS on Early Postoperative Outcomes

The purpose of this study is to evaluate whether actively suctioning the renal collecting system to induce a "collapse" state at the end of retrograde intrarenal surgery (RIRS) can reduce postoperative pain and infection in patients with kidney stones. Participants will be randomly assigned to either the experimental group (suction-induced collapse) or the control group (standard drainage). The study aims to determine if this simple surgical modification can improve early recovery outcomes and patient satisfaction.

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Key information

Conditions

Kidney Stones Calculi Female Urogenital Diseases Female Urogenital Diseases and Pregnancy Complications Kidney Calculi Kidney Diseases Male Urogenital Diseases Nephrolithiasis Neurologic Manifestations Pain Pain, Postoperative Pathologic Processes Pathological Conditions, Anatomical Pathological Conditions, Signs and Symptoms Postoperative Complications Renal Calculi Signs and Symptoms Urinary Calculi Urogenital Diseases Urolithiasis Urologic Diseases

Age range

20 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Kangdong Sacred Heart Hospital

Gandong-gu, Outside U.S./Canada, 05355, South Korea

Location status: Recruiting

Location contact

Han Kyu Chae

CONTACT

[email protected]

8201091869125

About this study

While RIRS is a standard treatment for kidney stones, postoperative flank pain and infectious complications remain significant issues. These complications are often associated with elevated intrarenal pressure and residual irrigation fluid left in the kidney after surgery.

This prospective randomized controlled trial investigates the clinical efficacy of a "suction-induced collapse" technique using a suction ureteral access sheath (UAS). In the experimental group, at the conclusion of RIRS, active suction will be applied through the UAS until the renal collecting system is visually confirmed to be collapsed. In the control group, standard drainage will be allowed after irrigation stops, without active suctioning.

The primary outcome is postoperative flank pain intensity measured by the Numerical Rating Scale (NRS) in the recovery room. Secondary outcomes include pain scores on postoperative day 1, the incidence of infectious complications (fever, UTI, or sepsis) within 7 days, and the total amount of analgesics used. A total of 90 patients will be enrolled to ensure statistical power.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Patients aged 20 to 80 years.
  • Patients diagnosed with kidney stones and scheduled for retrograde intrarenal surgery (RIRS).
  • Patients who have voluntarily signed the written informed consent form

Exclusion criteria

  • Participation in another clinical trial (drug or device) within 1 month prior to enrollment.
  • Congenital abnormalities of the urinary or reproductive system.
  • Presence of a pre-placed ureteral stent (pre-stenting) at the time of surgery.
  • Solitary kidney.
  • Uncontrolled urinary tract infection.
  • History of ureteral reconstruction on the affected side.
  • Pregnancy.
  • Uncorrectable bleeding diathesis or ongoing therapeutic anticoagulation therapy.
  • Contraindications to general anesthesia.
  • Other conditions that the investigator deems inappropriate for participation in the study.

Treatment and study plan

Complete suction-induced collapse

Procedure

At the end of Retrograde Intrarenal Surgery (RIRS), active suctioning is performed through a suction ureteral access sheath (UAS) until the renal collecting system is visually confirmed to be collapsed.

Other names: Suction collapse, Active suctioning through UAS

Standard RIRS with natural drainage

Procedure

Standard Retrograde Intrarenal Surgery (RIRS) procedure is performed. At the end of the surgery, only natural drainage is allowed after stopping irrigation, without any additional active suctioning.

Other names: Control procedure, Standard drainage

Primary outcomes

  1. Postoperative flank pain intensity

    Time frame: Within 1 hour after arrival in the post-anesthesia care unit (PACU)

    Pain is assessed using an 11-point Numerical Rating Scale (NRS), where 0 represents no pain and 10 represents the worst possible pain.

Secondary outcomes

  1. Postoperative pain intensity as measured by the Numerical Rating Scale (NRS)

    Time frame: 24 ± 4 hours after surgery

    Pain intensity will be assessed using an 11-point Numerical Rating Scale (NRS), where 0 represents "no pain" and 10 represents "the worst possible pain." Higher scores indicate more severe pain.

  2. Incidence of infectious complications

    Time frame: Within 7 days after surgery

    Includes fever (≥ 38.0°C), urinary tract infection (UTI), or sepsis within 7 days postoperatively.

Study contacts

Contact information is provided by the study sponsor or research team.

Han Kyu Chae, M.D., Ph.D.

CONTACT

[email protected]

+821091869125

Sponsors and collaborators

Lead sponsor

Kangdong Sacred Heart Hospital

Other

Registry information

Official study title

Effect of Complete Suction-Induced Collapse of the Renal Collecting System at the End of Retrograde Intrarenal Surgery on Early Postoperative Outcomes: A Prospective Randomized Study

Important dates

Study start
2026
Primary completion
2027
Study completion
2027
First posted
Apr 17, 2026
Registry last updated
Apr 23, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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