Real-World Study of Obstructive Upper Urinary Tract Stones and Acute Pyelonephritis

Real-World Study on Management Strategies for Upper Urinary Tract Stone Obstruction Complicated by Acute Pyelonephritis

Upper urinary tract stone obstruction complicated by acute pyelonephritis is a critical urological emergency requiring urgent decompression and infection control, yet real-world clinical decisions regarding the choice between retrograde ureteral stenting, percutaneous nephrostomy, or initial antibiotic therapy often vary based on physician experience and resource availability. This prospective, multi-center, observational study aims to enroll 1,650 patients across more than 30 hospitals in China to systematically evaluate the technical success rates, infection control efficacy, and safety profiles of these different management strategies. By analyzing natural clinical cohorts without intervening in routine practice, the study seeks to define the optimal application boundaries for retrograde stenting, evaluate the role of nephrostomy as a primary or salvage treatment, and establish risk models to predict the failure of conservative antibiotic therapy, ultimately providing high-level evidence for individualized and precise clinical decision-making.

Study Overview

• Status: Not yet recruiting
• Conditions: Urolithiasis; Pyelonephritis Acute; Observation; Strategy Training
• Intervention / Treatment: Procedure: Ureteral Stent; Procedure: Percutaneous Nephrostomy; Drug: Initial Medical Therapy

Detailed Description

Although current clinical consensus suggests that both percutaneous nephrostomy and retrograde ureteral stenting are effective for decompressing the upper urinary tract, real-world data suggest that retrograde stenting is chosen in the vast majority of cases due to its minimally invasive nature, leaving a critical knowledge gap regarding its specific failure risk factors and the precise indications for primary nephrostomy. Furthermore, a subset of patients who meet drainage criteria are initially treated with antibiotics alone due to non-medical factors such as patient preference or resource constraints, but the safety and failure boundaries of this conservative approach have not been well-documented. This study is designed as a prospective observational cohort study where 1,650 patients will be naturally assigned to treatment cohorts based on the initial clinical decision, including initial retrograde stenting, initial nephrostomy, or initial antibiotic therapy. Participants must present with CT-confirmed unilateral stone obstruction, fever or chills, and signs of systemic inflammation or organ dysfunction to ensure a well-defined study population.

The researchers will record detailed baseline data including stone characteristics, infection severity scores, and a unique physician-based subjective risk assessment to capture the nuances of clinical decision-making logic in real-time. The primary endpoint is the technical success rate of retrograde ureteral stenting, while secondary endpoints include the time to clinical stability, 30-day major complication rates, salvage treatment requirements, and renal function recovery metrics measured by creatinine and glomerular filtration rate changes. To address the expected sample size imbalance between treatment groups, the statistical analysis plan will utilize propensity score matching and inverse probability of treatment weighting to ensure robust comparisons. Ultimately, the study will develop visualization tools such as nomograms to predict the failure of retrograde stenting and conservative treatment, bridging the gap between clinical guidelines and real-world emergency management to improve patient safety and resource allocation.

• Study Type: Observational
• Enrollment (Estimated): 1650

Contacts and Locations

• Study Contact: Name: Yi Shao; Phone Number: 021-63240090; Email: drshaoyi@163.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

The study population consists of adult patients presenting to emergency or urology departments with acute pyelonephritis secondary to unilateral upper urinary tract stone obstruction. This group represents a clinically high-risk population in the real-world setting, characterized by the presence of both mechanical urinary obstruction (confirmed by imaging) and systemic inflammatory responses. By including patients with symptoms ranging from localized flank pain to systemic markers such as SIRS or qSOFA abnormalities, the cohort encompasses the full clinical spectrum of obstructive pyelonephritis, from early-stage infection to the initial signs of urosepsis. The population reflects real-world clinical practice where urgent decisions must be made between retrograde stenting, percutaneous nephrostomy, or initial conservative medical management.

Description

Inclusion Criteria:

• Informed consent has been obtained from the patient.
• Unilateral upper urinary tract stone obstruction (accompanied by dilatation of the renal pelvis and/or ureter) confirmed by non-contrast CT (NCCT).
• Presence of fever (body temperature ≥38.0°C) and/or chills.
• Meet at least one of the following conditions:
• SIRS Criteria: Meeting at least two of the following: heart rate >90 bpm; respiratory rate >20 breaths/min; white blood cell count >12×10⁹/L or <4×10⁹/L.
• Flank or Abdominal Pain: Persistent dull pain or colic in the flank or upper abdomen on the affected side.
• qSOFA Abnormality: Meeting at least one of the following: altered mental status; systolic blood pressure <100 mmHg; respiratory rate ≥22 breaths/min.

Exclusion Criteria:

• Pregnant or lactating women.
• Non-calculous obstruction (e.g., tumors, retroperitoneal fibrosis, congenital stenosis).
• Any form of drainage or surgical treatment performed on the affected kidney for the target stone prior to admission.
• Concurrent abdominal or pelvic emergency requiring urgent surgery.
• Non-functional affected kidney (preoperative imaging suggesting renal cortical thickness <5 mm or clinical assessment of no renal function).

Study Plan

How is the study designed?

Number of groups / cohorts

3

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Ureteral Stent (RUS) Group; Retrograde placement of a ureteral stent via the transurethral approach to relieve the obstruction	Procedure: Ureteral Stent; Retrograde placement of a ureteral stent via the transurethral approach to relieve the obstruction.
Percutaneous Nephrostomy (PCN) Group; Placement of a nephrostomy tube via percutaneous access to provide drainage and relieve the obstruction.	Procedure: Percutaneous Nephrostomy; Placement of a nephrostomy tube via percutaneous access to provide drainage and relieve the obstruction.
Initial Medical Therapy Group; Conservative management with initial antimicrobial therapy to control infection, without immediate surgical drainage.	Drug: Initial Medical Therapy; Conservative management with initial antimicrobial therapy to control infection, without immediate surgical drainage.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Technical Success Rate of Retrograde Ureteral Stenting	Defined as successful retrograde placement of a ureteral stent into the renal pelvis, verified by postoperative imaging for correct positioning.	Perioperative/Periprocedural

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time to Clinical Stability	The duration (in hours) from the initiation of the assigned treatment until all the following criteria are met and maintained for a period of 24 hours: body temperature <37.3°C, heart rate <90 beats/min, respiratory rate <20 breaths/min, and systolic blood pressure ≥90 mmHg.	from the initiation of the assigned treatment until all the following criteria are met and maintained for a period of 24 hours
Incidence of Major Complications:	The occurrence of any of the following events within 30 days: septic shock; new-onset organ failure (requiring mechanical ventilation or vasopressors); major hemorrhage requiring intervention (hemoglobin decrease >2 g/dL, or requiring blood transfusion, interventional radiology, or surgery); and serious complications related to the drainage procedure.	within 30 days
Proportion of Salvage Treatment	The proportion of patients converted to PCN after initial RUS failure, and the proportion of patients converted to invasive drainage (either RUS or PCN) following the failure of initial medical therapy.	Day 1 After Initial Medical Therapy
Failure of Initial Medical Therapy	Defined as the requirement for emergency conversion to PCN or RUS due to any of the following: occurrence of septic shock (requiring vasopressors); peak body temperature failing to show a downward trend or procalcitonin (PCT) levels increasing by >20% within 48 hours despite adequate anti-infective treatment; patient's request for intervention due to unbearable pain or worsening infection symptoms; or development of new organ dysfunction.	Day 1 After Initial Medical Therapy
Total length of hospital stay		From admission to discharge (up to 30 days)
The change in serum creatinine from baseline to discharge		From admission (baseline) to discharge (up to 30 days)
ICU admission rate and duration		From admission to discharge (up to 30 days)
Total medical expenditures during hospitalization.		From admission to discharge (up to 30 days)
the minimum estimated glomerular filtration rate (eGFR) recorded during the hospital stay		From admission to discharge (up to 30 days)
the proportion of patients experiencing a ≥25% decrease in eGFR at discharge compared to baseline.		From admission (baseline) to discharge (up to 30 days)
Urinary ultrasound findings	In participating centers with follow-up capacity, serum creatinine levels and urinary ultrasound findings (to assess changes in renal parenchymal thickness) will be collected at 3 months (±7 days) post-discharge. These data will be used for exploratory analysis and will not be included in the derivation of the primary conclusions.	at 3 months (±7 days) post-discharge
Serum creatinine levels	In participating centers with follow-up capacity, serum creatinine levels and urinary ultrasound findings (to assess changes in renal parenchymal thickness) will be collected at 3 months (±7 days) post-discharge. These data will be used for exploratory analysis and will not be included in the derivation of the primary conclusions.	at 3 months (±7 days) post-discharge

Collaborators and Investigators

• Sponsor: Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine

Study record dates

Study Major Dates

• Study Start (Estimated): October 1, 2026
• Primary Completion (Estimated): October 1, 2029
• Study Completion (Estimated): November 1, 2029

Study Registration Dates

• First Submitted: August 30, 2026
• First Submitted That Met QC Criteria: September 10, 2026
• First Posted (Actual): September 14, 2026

Study Record Updates

• Last Update Posted (Actual): September 14, 2026
• Last Update Submitted That Met QC Criteria: September 10, 2026
• Last Verified: September 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Urogenital Diseases; Male Urogenital Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urolithiasis; Diagnostic Techniques and Procedures; Diagnosis; Surgical Procedures, Operative; Urologic Surgical Procedures; Urogenital Surgical Procedures; Diagnostic Techniques, Urological; Ostomy; Urinary Diversion; Nephrotomy; Nephrostomy, Percutaneous
• Other Study ID Numbers: 20260830

Plan for Individual participant data (IPD)

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

Drug and device information, study documents

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