The impact of renal angiomyolipoma on estimated glomerular filtration rate in patients with tuberous sclerosis complex.

Abstract

BACKGROUNDThere is a growing concern that renal impairment may develop in patients with renal angiomyolipomas (AMLs) associated with tuberous sclerosis complex (TSC) as a consequence of the disease itself and/or the interventions to mitigate the risk of hemorrhage.OBJECTIVETo assess the estimated glomerular filtration rate (eGFR) in patients with bilateral renal AMLs and the impact of tumor burden and intervention on renal function.DESIGNRetrospective study.SETTINGUrology department of a tertiary care hospital.PATIENTS AND METHODSAll adult patients (≥18 years of age) with TSC-associated renal AMLs seen from October 1998 to June 2015. We included only patients with bilateral tumors or solitary kidneys at the last follow-up.MAIN OUTCOME MEASURESThe eGFR, renal volume, and number and type of interventions.RESULTSWe identified 12 patients (median age 27.6, interquartile range 23.7–39.9 years), a median follow-up period of 1266 days (33–3133), and a median renal size of 454.7 mL (interquartile range 344.7–1016.9 on the right side; 558.1 mL, interquartile range 253.7–1001.4 on the left). In 11 (91.7%) patients, the eGFR was >60 mL/min/1.77 m2. Six patients had three total nephrectomies, one had a contralateral partial nephrectomy, and seven had selective arterial embolizations. Intervention was associated with a significantly reduced eGFR. The renal size did not correlate with the eGFR.CONCLUSIONSTSC-associated renal AMLs may attain a large size but normal renal function is maintained in 92% of patients. Interventions to mitigate the risk of hemorrhage are associated with decreased renal function.LIMITATIONSThe renal size was used as a surrogate for tumor size. Other limitations were the limited number of patients and lack of split renal function testing.