A Case of Page Kidney Secondary to Spontaneous Bilateral Retroperitoneal Hemorrhage

Introduction: Page kidney is an uncommon etiology for secondary hypertension and renal insufficiency in which outward mass effect causes stimulation of the renin-angiotensin-aldosterone system (1). Although the exact prevalence is difficult to estimate given its rarity, Page kidney is typically traumatic or iatrogenic with subcapsular hematoma formation (2). We report a case of Page kidney in an elderly male with spontaneous bilateral retroperitoneal hemorrhage and bilateral renal artery stenosis. Case Description: An 83-year-old male with hypertension and chronic kidney disease presented for cough. His hospitalization was complicated by asymptomatic, severe hypertension with a systolic blood pressure ranging from 180 to 230 mm Hg. On hospital day 5, he developed abdominal distension and acute anemia from 9 to 7g/dl. There was no history of trauma or therapeutic anticoagulation. An abdominal computed tomography angiography revealed displacement of the left kidney by retroperitoneal hematoma and stenosis of bilateral renal arteries. On hospital day 7, he underwent a left iliolumbar and L4 lumbar artery embolization. Nevertheless, his renal dysfunction progressed. Continuous renal replacement therapy was initiated on hospital day 10, with successive transition to intermittent hemodialysis. He exhibited spontaneous renal function recovery without further dialysis requirements. However, he was transitioned to comfort care on hospital day 16 given an unrelated acute coronary syndrome with poor cardiac catheterization candidacy. Discussion: This case is unique because it illustrates the interplay between two rare entities. Page kidney is commonly due to trauma or abdominal instrumentation. In our case, this phenomenon was secondary to spontaneous retroperitoneal hemorrhage (SRH), a rare condition on its own. The recognition of a reversible cause of secondary hypertension by external compression of the renal parenchyma prompted rapid treatment without unnecessary testing. Failure to identify extrinsic renal compression may result in irreversible kidney failure. Furthermore, the resultant hypertension may mask hemodynamic compromise, providing a false sense of stability in SRH, a potentially fatal condition. It is important to consider extrinsic renal compression as an etiology of hypertension and acute kidney injury in patients with spontaneous retroperitoneal bleeding.