[HUGE RENAL ANGIOMYOLIPOMA COMPLICATED WITH COMMON ILIAC VEIN THROMBUS BECAUSE OF THE TUMOR PRESSURE]

A 47-year-old woman was transferred to our hospital in June 2014 in hemorrhagic shock due to rupture of a huge right renal angiomyolipoma (AML). Selective right renal arterial embolization performed that same day reversed the shock immediately. Despite the huge abdominal tumor, the patient was discharged 2 weeks later after refusing any further treatment.Two weeks later she noticed the abdominal tumor growing. One month after discharge, she was readmitted due to dyspnea caused by restriction of her breathing by the growing tumor mass. A CT revealed a massive increase in tumor size with internal liquefaction, a thrombus in the left common iliac vein, and a 12 mm aneurysm in the right renal artery. The patient requested removal of the abdominal tumor since her ADL had deteriorated. We decided to perform a right nephrectomy with consideration of the left common iliac vein thrombus and right renal arterial aneurysm.As a precaution against pulmonary embolism in case the left common iliac vein thrombus dislodged, a retrievable inferior vena cava (IVC) filter was inserted before surgery. We were also concerned about possible rupture of the right renal aneurysm, so the right renal artery was embolized before surgery. After these procedures, a right nephrectomy was performed via a transperitoneal approach.The surgery was uneventful. The tumor weighed about 11 kg including 7,000 mL of bloody fluid. The IVC filter was removed the day after surgery, but the thrombus in the left common iliac vein remained, and an anticoagulant was started. Three months later, the thrombus had disappeared, and the anticoagulant was discontinued six months after surgery.According to the treatment guidelines for deep vein thrombosis, anticoagulants are the drugs of choice. IVC filters are seldom used to prevent pulmonary embolism. We initially administered an anticoagulant for the thrombus in the left iliac vein. However, an increase in abdominal tumor size suggested the drug had caused internal rebleeding and it had to be discontinued. Ultimately, we used a temporary retrievable IVC filter during the right nephrectomy with success.There is currently no consensus on when to use an IVC filter. Moreover, very little data exists on the use of an IVC filter during the perioperative period. Therefore, given the risk of potential thromboembolism, although we were able to use it successfully in our surgery, it should not be employed without a thorough benefit-risk assessment.