A middle-aged patient with metastatic colon cancer had severe hydronephrosis due to a metastatic mass in the pelvis and ureteral involvement, and other nephrologists had implanted a nephrostomy for the patient. Unfortunately, the patient had persistent hematuria from the nephrostomy tube, resulting in a decrease in hemoglobin. The patient was referred to the intervention service. After a left kidney angiography revealed a pseudoaneurysm in the kidney's lower bridge, embolization was performed on the patient, preventing hematuria.