Treatment of renal angiomyolipoma

Evaluation of renal function of angiomyolipoma patients after selective transcatheter arterial embolization

BACKGROUND

Angiomyolipoma patients may have renal insufficiency before selective transcatheter arterial embolization (TAE) or may undergo subsequent surgery after TAE. Therefore, this retrospective study examined our experience with TAE or TAE and subsequent surgery on renal function of angiomyolipoma patients with and without preexisting renal insufficiency.

METHODS

25 patients who had undergone TAE for renal angiomyolipoma over a 7-year period were reviewed. The 25 patients were grouped according to whether or not they had undergone further surgery. Preexisting renal insufficiency was compared between the 2 groups. The TAE and surgery group was further subdivided into 2 subgroups according to total nephrectomy or not. The TAE-alone group was further subdivided into 2 subgroups by presence of preexisting renal insufficiency or not. In each group and subgroup, pre-TAE and post-TAE renal function, including serum creatinine and creatinine clearance were compared.

RESULTS

TAE rather than TAE and surgery was more likely chosen in the presence of preexisting renal insufficiency (6/13 versus 1/12, P=0.035). In TAE-alone patients, no statistical differences were noted between serum creatinine and creatinine clearance before and after TAE. Conversely, TAE and surgery patients who had undergone total nephrectomy rather than nephron-sparing surgery differed significantly in preand post-TAE serum creatinine (0.77 versus 1.07, P=0.014) and creatinine clearance (98.1 versus 70.7, P=0.032).

CONCLUSIONS

This study demonstrated that TAE alone for treating renal angiomyolipomas was able to preserve renal function, despite the presence of mild preexisting renal insufficiency. Conversely, surgery after TAE, particularly total nephrectomy, should be avoided whenever possible.

Renal artery embolization: clinical indications and experience from over 100 cases

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.