Ureteropelvic Junction Obstruction

Ureteropelvic junction (UPJ) obstruction is a condition that involves the blockage or narrowing of the area where the ureter (the tube that carries urine from the kidneys to the bladder) connects to the renal pelvis (the central collecting area of the kidney). This obstruction can impede the flow of urine from the kidney to the bladder, leading to a buildup of urine in the kidney and potentially causing various symptoms and complications.


UPJ obstruction can be congenital (present at birth) or acquired. Congenital UPJ obstruction occurs when the ureter and renal pelvis do not develop properly during fetal development. Acquired UPJ obstruction can be caused by factors such as kidney stones, scar tissue, or blood vessel compression that obstruct the passage of urine.


The severity of symptoms can vary depending on the degree of obstruction and how well the other kidney compensates. Common symptoms include:

  • Flank pain or discomfort, usually on the side of the affected kidney.
  • Recurrent urinary tract infections (UTIs).
  • Hematuria (blood in the urine).
  • Abdominal or pelvic pain, especially in cases of severe obstruction.
  • Palpable abdominal mass (rarely).


UPJ obstruction is typically diagnosed through a combination of imaging studies and clinical evaluation. Common diagnostic methods include:

  • Ultrasound: To visualize the kidneys and urinary tract.
  • CT scan: Provides detailed images of the kidney and the obstruction.
  • Magnetic Resonance Urography (MRU): A specialized MRI to assess urinary tract anatomy and function.
  • Voiding Cystourethrogram (VCUG): A test to evaluate bladder and urethral function.


Treatment options depend on the severity of the obstruction, the presence of symptoms, and the impact on kidney function. Options include:

  • Observation: If the obstruction is mild and not causing significant symptoms, periodic monitoring may be recommended.
  • Surgery: Surgical intervention might be necessary if the obstruction is severe or causing complications. Surgical procedures include pyeloplasty, which involves removing or repairing the obstructed part of the ureter and reattaching it to the renal pelvis.
  • Endoscopic Techniques: In some cases, minimally invasive procedures can be performed using a thin tube (endoscope) to remove or dilate the obstruction.
  • Stent Placement: A small tube (stent) can be placed temporarily to help maintain urine flow while waiting for definitive treatment.


The prognosis for UPJ obstruction depends on the severity of the obstruction, the age of the patient, and how quickly the condition is diagnosed and treated. Prompt diagnosis and appropriate management can help prevent complications and preserve kidney function.

If you suspect you or someone you know might have UPJ obstruction, it’s important to seek medical attention. A urologist or a healthcare provider with expertise in urologic conditions can provide a proper diagnosis and recommend appropriate treatment options based on the individual’s specific situation.

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