A Ureteropelvic Junction (UPJ) obstruction is a structural blockage occurring at the exact point where the kidney's pelvis connects to the ureter (the long tube that drains urine down into the bladder). This constriction blocks the natural outflow of urine from the kidney, forcing fluid to pool inside the delicate kidney tissues. This backup creates a high-pressure environment that causes the kidney to swell (hydronephrosis), which can cause deep flank pain and, if left uncorrected, permanent decline in long-term kidney function.

Primary Symptoms

• Flank or Back Pain: A deep, dull, or aching pain located in the upper back, side, or flank, which frequently intensifies significantly after drinking high volumes of fluids or alcohol.

• Recurrent Kidney Infections: Persistent bouts of fever, chills, and flank pain caused by bacteria multiplying in the stagnant, trapped urine.

• Nausea and Vomiting: Systemic discomfort or digestive upset triggered directly by episodes of acute kidney pressure.

Diagnostic Approach

1. Renal Function Scan (MAG3 Scan): A specialized nuclear medicine imaging study that maps the exact transit time of fluid through the kidney to quantify the severity of the drainage blockage.

2. CT Urogram or Ultrasound: High-definition cross-sectional imaging to visually evaluate the structural degree of kidney swelling and look for any overlapping blood vessels crossing and pinching the junction.

Recommended Surgical & Treatment Pathways

Dedicated Subspecialty Center: Robotic Ureteral Reconstruction & Upper Tract Care Hub →

Surgical Reconstruction: Ureteroplasty (Robotic Pyeloplasty) — Dismembered Anderson-Hynes pyeloplasty restoring unrestricted renal pelvis drainage.

Diagnostic Imaging & Labs: CT Abdomen & Pelvis Results Explained →