Reduction of Postembolization Syndrome After Ablation of Renal Angiomyolipoma John J. Bissler, MD, John Racadio, MD, Lane F. Donnelly, MD, and Neil D. Johnson, MD ● Approximately 75% of patients with tuberous sclerosis complex develop renal angiomyolipomas. These hamar- tomatous lesions distort and damage renal parenchyma and can lead to hemorrhage. To reduce the risk of hemorrhage, transarterial embolization is used to necrose the angiomyolipoma while sparing normal renal tissue. Although an effective renal-sparing procedure, embolization most often is associated with an inflammatory response that causes significant fever and pain that can last for several days despite the use of acetaminophen. Reported cases show that 49 of 55 patients who underwent embolization developed this syndrome. The use of such nonsteroidal anti-inflammatory drugs as aspirin is contraindicated because of their adverse effects on platelet function. To reduce pain and fever associated with postembolization syndrome (PES), we changed our clinical management of patients postembolization to include a tapering dose of prednisone over a 2-week period. Nine patients underwent this pharmacological intervention, and one patient abstained. All patients were monitored for pain and fever. Only two patients treated with steroids developed fever, which was assuaged with acetaminophen, and no patient reported pain. The tapering dose of prednisone was well tolerated, and there were no postprocedure infections. The use of a short-term tapering dose of prednisone appeared to reduce PES compared with the reported literature and improved patient comfort. © 2002 by the National Kidney Foundation, Inc. INDEX WORDS: Tuberous sclerosis complex (TSC); angiomyolipoma; postembolization syndrome (PES). T UBEROUS SCLEROSIS complex (TSC) is an autosomal dominant inherited disease with a variable phenotype. 1 Renal manifestations of TSC are angiomyolipomas, cysts, and malig- nant tumors. Angiomyolipomas occur in 75% of children with renal lesions 2 and are described as hamartomatous lesions consisting of abnormal vessels, smooth muscle, and adipose tissue. 3 These tumors demonstrate a clonal nature as well as a loss of heterozygosity, such that only the mutant allele can be identified at the TSC lo- cus. 4,8 These lesions may be discretely focal or coalesce into diffuse masses. Typically, angio- myolipomas are present in the young 2 and con- tinue to grow during adulthood. 9-11 These lesions distort renal architecture and can compromise function. Renal failure is a long-term complica- tion of TSC 2,12 and the leading cause of death in adults. 13 Although somewhat rare, angiomyolipo- mas also can undergo malignant degeneration. 14 Dysmorphic blood vessels in the angiomyoli- poma can have microaneurysms 15 or macroaneu- rysms. 16 These aneurysms may rupture and hem- orrhage, resulting in significant morbidity and, possibly, death. Symptomatic angiomyolipomas have been treated by total nephrectomy, partial nephrec- tomy, enucleation, and embolization. Because of the loss of renal tissue, total nephrectomy is not optimal and is reserved for life-threatening con- ditions. Uncontrollable hemorrhage during par- tial nephrectomy and enucleation may necessi- tate total nephrectomy. Transarterial embolization, first used more than 20 years ago, 17 has become the treatment of choice because of the renal- sparing nature of this procedure. 18 Embolization can stop active bleeding or may be used prophy- lactically to treat large lesions believed to be at risk for hemorrhage. An impediment to embolization is postemboli- zation syndrome (PES). This syndrome causes pain and fever that can be severe. 11,17,19-29 PES likely is caused by an inflammatory response to necrotic tissue after embolization. Burn et al 30 reported a patient with T 2 -weighted magnetic resonance imaging findings compatible with liqui- factive necrosis. Embolization of uterine fi- broids 30 and whole kidneys 31 in non–surgical candidates led to significant pain and fever. In- flammatory mediators in embolic and ischemic From the Divisions of Nephrology and Hypertension and the Department of Radiology, Children’s Hospital Medical Center, Cincinnati, OH. Received September 14, 2001; accepted in revised form November 30, 2001. Supported in part by grants from the PKD Foundation and Tuberous Sclerosis Association (J.J.B.). Address reprint requests to John J. Bissler, MD, Children’s Hospital Research Foundation #5, 3333 Burnet Ave, Cincin- nati, OH 45229-3039. E-mail: john.bissler@chmcc.org © 2002 by the National Kidney Foundation, Inc. 0272-6386/02/3905-0007$35.00/0 doi:10.1053/ajkd.2002.32770 American Journal of Kidney Diseases, Vol 39, No 5 (May), 2002: pp 966-971 966