Background: Ureteropelvic junction obstruction (UPJO) is a common cause of pediatric hydronephrosis and may lead to progressive renal parenchymal damage and functional impairment if left untreated. Early diagnosis and timely surgical intervention are essential to preserve renal function. Vascular hitch procedures have emerged as a minimally invasive alternative to dismembered pyeloplasty in selected patients with extrinsic ureteropelvic junction compression. Case Presentation: A 12-year-old male presented with intermittent right flank pain, nausea, and vomiting. Clinical examination revealed mild right flank tenderness, while laboratory investigations showed preserved renal biochemical parameters. Ultrasonography demonstrated gross right hydroureteronephrosis with marked cortical thinning. Computed tomography of the kidneys, ureters, and bladder confirmed severe hydronephrosis with significant dilatation of the renal pelvis and moderate thinning of the renal parenchyma, consistent with ureteropelvic junction obstruction. A 99mTc-diethylenetriamine pentaacetic acid (DTPA) renal scan revealed gross right hydronephrosis with significantly impaired cortical function and an obstructive drainage pattern. Differential renal function was 30% in the right kidney and 70% in the left kidney. The patient underwent a vascular hitch procedure for relief of obstruction caused by a crossing vessel. Outcome: The postoperative course was uneventful. The patient received appropriate antimicrobial therapy, analgesics, hydration, and supportive pharmaceutical care. Follow-up ultrasonography performed three months after surgery demonstrated marked reduction in hydronephrosis and improvement in cortical thickness. Serum creatinine remained stable at 0.64 mg/dL, and the patient remained asymptomatic.

Conclusion: This case highlights the importance of comprehensive diagnostic evaluation in pediatric UPJO and demonstrates that a vascular hitch procedure can be an effective treatment option in carefully selected patients with extrinsic ureteropelvic junction obstruction. Early intervention and multidisciplinary perioperative care are crucial for preserving renal function and optimizing clinical outcomes.

Keywords: Ureteropelvic junction obstruction; Hydronephrosis; Cortical thinning; Pediatric urology; Vascular hitch; Renal function; Case report