Renal SWE as a Predictor After Pediatric Pyeloplasty for UPJO

This is a prospective longitudinal observational cohort study conducted at the Department of Urology, Faculty of Medicine, Beni-Suef University.

The study will include children aged 6 months to 18 years with unilateral primary ureteropelvic junction obstruction who are scheduled for open dismembered pyeloplasty. Eligible children will undergo standard preoperative clinical assessment, laboratory investigations, renal ultrasonography, renal cortical shear wave elastography, and renal isotope assessment.

Preoperative imaging will include renal ultrasonography to assess hydronephrosis, anteroposterior pelvic diameter, and renal cortical thickness. Renal cortical shear wave elastography will be performed to measure cortical stiffness in the affected kidney. Renal isotope assessment will include diuretic renography for differential renal function and drainage assessment, with renal cortical scintigraphy when clinically indicated according to the approved protocol.

All included patients will undergo open dismembered pyeloplasty according to standard surgical principles. Postoperative follow-up will include clinical assessment, renal ultrasonography, and renal cortical shear wave elastography at 3 and 6 months. A repeat renal isotope study will be performed at 6 months after surgery to reassess differential renal function and drainage.

The primary outcome is the predictive performance of the change in renal cortical shear wave elastography from baseline to 3 months postoperatively for 6-month isotope-defined renal functional recovery after pyeloplasty. Secondary outcomes include the association between 3-month postoperative shear wave elastography and functional recovery, longitudinal changes in shear wave elastography, postoperative changes in differential renal function and drainage parameters, and improvement in ultrasonographic parameters after pyeloplasty.

Inclusion criteria

• Children aged 6 months to 18 years.
• Diagnosis of unilateral primary ureteropelvic junction obstruction.
• Planned for open dismembered pyeloplasty.
• Availability of preoperative renal ultrasonography, renal cortical shear wave elastography, and diuretic renography.
• Written informed consent obtained from parent or legal guardian.

Exclusion criteria

• Bilateral ureteropelvic junction obstruction.
• Secondary ureteropelvic junction obstruction.
• Previous ipsilateral upper urinary tract surgery.
• Associated major urinary tract anomalies likely to independently affect renal function, including vesicoureteral reflux, megaureter, duplex system, posterior urethral valves, or ectopic kidney.
• Active urinary tract infection at the time of assessment.
• Known intrinsic renal parenchymal disease unrelated to obstruction.
• Inability to obtain reliable shear wave elastography measurements.
• Incomplete planned follow-up.