Abstract 18571: Fetal Sirolimus Therapy for Giant Cardiac Rhabdomyoma

Abstract

Background: Cardiac rhabdomyomas in tuberous sclerosis regress spontaneously, large masses can cause hemodynamic compromise. Fetal sirolimus therapy cause regression. We report a case of successful fetal therapy in mother with fetally diagnosed tuberous sclerosis (TS). Case: A 22 year old female with uncomplicated pregnancy and negative cardiac history presented for fetal echocardiogram at 21 weeks due to cardiac masses. Fetal echocardiogram: levocardia, normal segmental cardiac anatomy, d-looped ventricles, normally related great arteries. Multiple masses seen in both ventricles, largest in LV free wall from base to apex and another involving mitral papillary muscle, no initial obstruction, patent ductal and aortic arches. Amniocentesis confirmed diagnosis of TS. Fetus was followed with serial monitoring of cardiac outputs and size of masses. At 30 weeks, LV mass had doubled from 1.7 to 4 cm with LV diastolic dysfunction and reduced cavity size, large pericardial effusion, left ventricular outflow tract obstruction (LVOTO). IVC was mildly dilated with liver enlargement. Fetal MRI confirmed diagnosis of rhabdomyoma with small subependymal nodules. Given LVOTO and large effusion, mother was started on sirolimus therapy with loading dose of 5 mg and subsequent dose adjustments for target trough sirolimus of 10 to 15 ng/ml. Serial mother monitored with labs, weekly ultrasounds and echocardiograms. Mass decreased in size with resolution of effusion and LVOTO. At 37 weeks, due to oligohydramnios, baby was delivered without hemodynamic compromise. Postnatally no LVOTO and normal systolic function with mass measuring ~ 2.0 cm. Baby has been followed off sirolimus therapy. Role of Imaging: Serial echocardiograms enabled optimal decision making to treat mother with sirolimus therapy. Conclusions: Maternal sirolimus therapy can help regress cardiac rhabdomyomas with hemodynamic implications with serial close outpatient monitoring.