Long-term Follow-up Assessing Renal Angiomyolipoma Treatment Patterns, Morbidity, and Mortality: An Observational Study in Tuberous Sclerosis Complex Patients in the Netherlands

Abstract

BACKGROUND: Long-term data from patients with tuberous sclerosis complex (TSC)-associated renal angiomyolipoma (angiomyolipoma) are limited. STUDY DESIGN: Retrospective observational study. SETTING & PARTICIPANTS: Adult patients with TSC treated at the University Medical Center Utrecht (the Netherlands) from January 1990 through April 2012. PREDICTORS: Patient age and angiomyolipoma stage, based on computed tomography lesion count, size, and impact on renal anatomy, with higher stage representing higher angiomyolipoma burden. Patients in stages 3 or higher were considered at high risk for hemorrhage and candidates for selective arterial embolization. OUTCOMES: Kidney-related outcomes included hypertension, anemia, decreased kidney function, dialysis, kidney transplantation, nephrectomy, kidney-related blood transfusions, and mortality. Observed mortality was compared to the Dutch National Bureau of Statistics using standardized mortality ratio. RESULTS: Median follow-up was 15.8 years, of which staging was available for 5.4 years. Of 351 patients with TSC, 244 (69.5%) had confirmed angiomyolipoma; 144 (59.0%) reached stage 3 or higher. Age and angiomyolipoma stage were positively correlated: median age in the none-detected stage was 36.8 years, increasing to 43.6 years for stage 6. Embolization was performed in 117 patients; 57 had 2 or more embolization procedures. Higher stage was associated with hypertension, anemia, decreased kidney function, and transfusion. Hypertension, anemia, and decreased kidney function were more common in patients who underwent selective arterial embolization. 7 patients required dialysis, 7 received a kidney transplant, and 16 underwent nephrectomy. 29 deaths were recorded, most commonly related to renal complications (n=9[31%]). Mortality was significantly higher in the study cohort versus the general population (standardized mortality ratio, 4.8; 95% CI, 3.4-6.9). LIMITATIONS: Duration of follow-up with staging was too short to observe stage progression in most patients. CONCLUSIONS: Despite the use of preventive selective arterial embolization, patients with TSC exhibit clinically significant kidney disease and excess mortality, largely because of kidney-related complications.