Ruptured Renal Artery Aneurysm in Late Pregnancy: Challenges in a Patient with Atrophic Kidney

BACKGROUND Renal artery aneurysms (RAA) are rare in the general population, with an incidence of 0.09%. Typically, they are asymptomatic and diagnosed incidentally on imaging for other indications. Women comprise 72% of those affected and are rare in pregnancy. Undiagnosed left renal atrophy occurs in 1.3% of the general population. Pregnancy is characterized by physiologic changes that result in an increased risk of renal artery aneurysm leaking, dissecting, and rupture. RAA rupture in the third trimester can result in a devastating maternal-fetal catastrophe, depending on the length of time from the rupture event to surgical resolution. CASE REPORT A 39-year-old woman with 1 previous cesarean delivery presented to our center at 36 weeks of gestation on transport from an outside emergency department with a sudden onset of right flank pain without vaginal bleeding, hematuria, or uterine contractions. On arrival, she was hypotensive and had an agonal fetal heart rate. An emergency cesarean delivery resulted in a depressed, acidotic infant. An expanding maternal retroperitoneal hematoma was found to be secondary to a ruptured RAA. Because of a newly-diagnosed atrophic left kidney, an endovascular repair of the right renal artery was performed. She was discharged on day 12. The infant was discharged after 6 months, meeting the developmental milestones. CONCLUSIONS A ruptured RAA in the third trimester of pregnancy is a potentially life-threatening event for both mother and infant. It is particularly complicated if the uninvolved kidney is atrophic, which limits surgical remedies. A robust team of available tertiary-level care units can improve the time from rupture to surgical intervention and can help decrease maternal and infant morbidity and mortality.