Clinical Evaluation of the Pelvic Floor Fatigue Index (PFFI)

NCT07763613 | Not Yet Recruiting

• 2 other identifiers: PFFI-2026-0110496660-2026/26214
• Study Type: observational
• Target: 75
• Locations: 1 country
• Sites: 1

Brief Summary

Background: Ureteral stent-related symptoms vary considerably among patients despite similar surgical procedures and stent characteristics. Although several mechanisms have been proposed, the reasons for this interindividual variability remain incompletely understood. Pelvic floor muscle endurance may represent one of the patient-related factors contributing to symptom severity. The Pelvic Floor Fatigue Index (PFFI) is a novel ultrasound-based index developed to quantify pelvic floor muscle endurance by measuring the percentage decline in bladder base elevation during a sustained maximum voluntary pelvic floor contraction using suprapubic transverse B-mode ultrasonography. This prospective observational study aims to clinically evaluate the PFFI by investigating the association between preoperative PFFI measurements and postoperative ureteral stent-related symptoms assessed using the Ureteral Stent Symptom Questionnaire (USSQ). In addition, the study will evaluate the test-retest reliability of the PFFI measurement method and explore its potential role as an objective functional assessment tool for pelvic floor muscle endurance. The findings of this study are expected to provide the first clinical evaluation of the PFFI and establish the methodological basis for future validation studies and broader clinical applications.

Conditions

Urolithiasis

Keywords

Pelvic Floor Fatigue Index; PFFI; Ureteral Stent; Ureteral Stent-Related Symptoms; Ureteral Stent Symptom Questionnaire; USSQ; Pelvic Floor Muscle Endurance; Urolithiasis; Ureteroscopy; Retrograde Intrarenal Surgery

Outcome Measures

Primary Outcomes (1)

• Association Between Preoperative PFFI and Postoperative Total USSQ Score

  The association between the preoperative Pelvic Floor Fatigue Index (PFFI) and postoperative ureteral stent-related symptom burden will be assessed using the total Ureteral Stent Symptom Questionnaire (USSQ) score obtained on postoperative Day 10. Higher PFFI values indicate greater pelvic floor fatigability, and higher total USSQ scores indicate greater stent-related symptom burden.

  Preoperative assessment to postoperative Day 10

Secondary Outcomes (3)

• Association Between Preoperative Dmax and Postoperative Total USSQ Score

  Preoperative assessment to postoperative Day 10

• Test-Retest Reliability of PFFI Measurement

  During the same preoperative assessment session, with approximately 10-15 minutes between measurements

• Change in PFFI From Preoperative Assessment to Postoperative Day 10

  Preoperative assessment and postoperative Day 10

Study Arms (2)

Pre-stented Group

Patients undergoing ureteroscopy or retrograde intrarenal surgery (RIRS) who have a ureteral stent in place before the index procedure.

Procedure: Ureteroscopy / Retrograde Intrarenal Surgery

Non-pre-stented Group

Patients undergoing ureteroscopy or retrograde intrarenal surgery (RIRS) without a ureteral stent in place before the index procedure.

Procedure: Ureteroscopy / Retrograde Intrarenal Surgery

Interventions

Ureteroscopy / Retrograde Intrarenal Surgery PROCEDURE

Ureteroscopy or retrograde intrarenal surgery (RIRS) will be performed for the treatment of urolithiasis according to routine clinical practice. No additional procedural intervention will be assigned by the study protocol.

Non-pre-stented Group; Pre-stented Group

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Adult patients with urolithiasis scheduled to undergo ureteroscopy (URS) or retrograde intrarenal surgery (RIRS) with postoperative double-J ureteral stent placement at the study center. Eligible participants will undergo standardized transabdominal ultrasonographic assessment of pelvic floor fatigability before surgery and will complete postoperative ureteral stent symptom assessment according to the study protocol.

You may qualify if:

• Adults aged 18-65 years. Diagnosis of urolithiasis requiring ureteroscopy (URS) or retrograde intrarenal surgery (RIRS).
• Planned postoperative double-J ureteral stent placement. Patients belonging to either the Non-pre-stented Group or the Pre-stented Group according to the study protocol.
• Ability to read and understand the validated Turkish version of the Ureteral Stent Symptom Questionnaire (USSQ).
• Ability to independently complete the USSQ. Ability to perform an adequate voluntary pelvic floor muscle contraction. Provision of written informed consent.

You may not qualify if:

• Clinically significant diabetic neuropathy. Neurological disorders affecting lower urinary tract function (e.g., multiple sclerosis, Parkinson's disease, spinal cord injury).
• Active lower urinary tract dysfunction (e.g., overactive bladder, neurogenic bladder, interstitial cystitis).
• Previous pelvic floor surgery. Known urinary incontinence. Urethral stricture. Chronic prostatitis. Recurrent urinary tract infection. Urinary tract malignancy. Advanced chronic kidney disease. Previous upper urinary tract reconstructive surgery. Pregnancy. Active urinary tract infection. Inability to perform an adequate voluntary pelvic floor muscle contraction. Inability to provide informed consent.

Sponsors & Collaborators

• Trabzon Kanuni Education and Research Hospital: lead

Study Sites (1)

Trabzon Kanuni Education and Research Hospital

Trabzon, Trabzon, 61080, Turkey (Türkiye)

Location

MeSH Terms

Conditions

Urolithiasis

Interventions

Ureteroscopy

Condition Hierarchy (Ancestors)

Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Male Urogenital Diseases

Intervention Hierarchy (Ancestors)

Endoscopy; Diagnostic Techniques, Surgical; Diagnostic Techniques and Procedures; Diagnosis; Diagnostic Techniques, Urological; Minimally Invasive Surgical Procedures; Surgical Procedures, Operative; Urologic Surgical Procedures; Urogenital Surgical Procedures

Central Study Contacts

ADEM DENİZ, MD

CONTACT

+904623330030; adeemdeniz@gmail.com

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: August 8, 2026
• First Posted: August 13, 2026
• Study Start: August 10, 2026
• Primary Completion (Estimated): December 25, 2026
• Study Completion (Estimated): December 25, 2026
• Last Updated: August 13, 2026

Record last verified: 2026-08

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)