High Grade Obstructive Ureterolithiasis

History: Right Flank Pain, eval for kidney stones, history of left side renal stones

Discussion: This case is an example of high grade ureteral obstruction and the associated changes in the proximal urinary system. The patient’s pain is secondary to the proximal hydroureter/ureterectasis and hydronephrosis/caliectasis. When describing obstructive stones, include the size of the stone, location of the stone, presence of proximal urinary tract dilatation. This patient has a history of obstructive urolithiasis on the left. It is important to note the other nonobstructing calculi within the renal collecting systems to evaluate the patient’s stone burden. This will also help the urologist with any surgical management. This patient had a prior CT that demonstrated the current obstructing calcus as a nonobstructing stone in the lower pelvis of the right kidney.

Prognosis: Stones <4 mm pass in 90%,
Stones 4-6 mm pass in 50%
Stones >6 mm rarely pass spontaneously

Reference:
Dahnert,"Radiology Review Manual". 7th ed. page 1004-7.