Abstract: SA-PO303
A Tough Nut to Crack
Session Information
- Trainee Case Reports - VI
October 27, 2018 | Location: Exhibit Hall, San Diego Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Trainee Case Reports
- 1403 Hypertension and CVD: Mechanisms
Authors
- Janosevic, Danielle, Indiana University School of Medicine, Indianapolis, Indiana, United States
- Eadon, Michael T., Indiana University Division of Nephrology, Indianapolis, Indiana, United States
Introduction
“Nutcracker Kidney” is a puzzling diagnosis which conventional imaging can miss. We present a case with a high degree of clinical suspicion wherein positional Doppler imaging was required to confirm the diagnosis.
Case Description
A 37 year old African American male with no past medical history presented with several months of intermittent gross hematuria associated with left sided flank pain radiating to his bladder, which was exacerbated with vigorous physical activity and would resolve completely with rest. He had been self-medicating for the pain with NSAIDs on a daily basis (200-400 mg/d). Physical exam revealed a male of thin, tall stature, with a mild tenderness over the suprapubic region and left CVA. Labs: serum creatinine of 1.21 mg/dl (GFR MDRD 82 ml/min/1.73 m2), and urine microscopy with non-dysmorphic red blood cells (>250 on UA, no WBC), 24 hour urine protein of 338 mg/day. Negative urine culture and urine fungal culture. C3 was 91 mg/dl, C4 was 10 mg/dl and ANA was negative. He had a normal hemoglobin electrophoresis, 24 h urine calcium 128 mg/d. CT scan of abdomen/pelvis was significant for absence of renal calculi, cysts, or hydroureteronephrosis. CT also noted an unremarkable bladder, no papillary necrosis, no AVM, and widely patent bilateral renal veins. A cystoscopy revealed negative cytology without bladder masses. A renal doppler study in the supine and standing position was obtained due to a high suspicion for dynamic renal vein compression. The study revealed a normal right renal vein in the supine, seated, and standing positions. Two left renal veins were noted. While one left renal vein was non-pathologic, the second left renal vein doppler showed intact flow in the supine and seated positions, but continuous flow suggestive of compression in the standing position. The patient was offered intravascular intervention, but elected conservative therapy by limiting provocative physical activity.
Discussion
“Nutcracker kidney” is a challenging clinical diagnosis. The mechanism of “nutcracker kidney” is venous hypertension from compression of the left renal vein between the aorta and superior mesenteric artery. Clinicians must maintain a high index of suspicion to diagnose it with targeted dynamic imaging. In this case, all standard imaging failed to reveal the etiology and only the use of positional (standing) Doppler interrogation confirmed the diagnosis.