This particular patient had transitional cell carcinoma of the bladder, which extended to the ureter compromising the outflow. This obstruction, thereby, resulted in a back flow up to the kidney where the urine distended the calices.
Bilateral ureteral obstruction is an extreme medical emergency. Unilateral is is a semi-emergency. Surgical intervention is usually required if the patient is in condition to withstand the surgical procedure.
Nephrostomy tubes are implanted in certain cases and in other cases, comfort measures ONLY-- seem to be the most humane choice.