Objective: To review current indications and techniques for renal artery embolization (RAE) and more specifically to review cases of RAE before nephrectomy for treating patients with a large renal mass.
Patients and methods: All RAEs done at our institution between May 1993 and December 2005 were reviewed. Patients were identified using a database assembled by the Division of Cardiovascular Interventional Radiology. Indications, techniques and RAE-related complications were then obtained from a retrospective review of medical records. Additional data for patients undergoing preoperative infarction were acquired, including estimated blood loss (EBL), transfusion requirement, pathological size, subtype, grade, stage, and level of tumour thrombus if present.
Results: In all, there were 121 RAEs, 69 in males and 52 in females (mean age 57.6 years, range 11-89). Metallic microcoils were the most often used embolization agent, followed by acrylic microspheres (embospheres), polyvinyl alcohol particles, absolute ethanol, and Gelfoam (Pharmacia & Upjohn, USA). The most common indication for RAE was infarction before nephrectomy (54.5%). Other indications included symptomatic angiomyolipomas, palliation of unresectable renal cancer, haemorrhage, perinephric bleeding in end-stage renal disease, vascular lesions, malignant hypertension, and sequelae of end-stage renal disease. RAE-associated complications including coil migration, incomplete embolization, and groin haematoma (in 5.0%). Symptoms of post-infarction syndrome were common, with 74.4% of patients having flank pain, nausea, or vomiting; the vast majority of these symptoms were mild and self-limited. In patients having nephrectomy after RAE the median (range) interval from RAE was 2 (0-78) days. The mean tumour size was 11.2 (3.5-25) cm and 46% of patients had tumour thrombus present in either the renal vein or inferior vena cava (IVC). The mean (median) overall EBL in patients having nephrectomy after RAE was 1048 (725) mL. The mean transfusion requirement over the course of hospitalization was 3.9 units of packed red blood cells.
Conclusions: RAE is a safe and effective therapeutic tool for many urological, renal and vascular conditions. Its use has increased at our institution due to improved techniques, embolization materials, and our increasing use of RAE as an adjuvant procedure for patients requiring nephrectomy with or without IVC thrombectomy. There are many potential operative advantages for patients having RAE before surgery, with minimal morbidity. It is likely that the lack of prospective randomized trials is the primary reason why it is underutilized in the preoperative setting.