RM is a 69 yo Caucasian male who was first admitted to an outside hospital in July 2002 with acute onset of severe infrascapular back pain. During this hospital admission, a CT scan with intravenous contrast revealed an aortic dissection extending to the right common iliac artery. A transesophageal echocardiogram showed a dissection flap originating at the level of the left subclavian artery and proceeding distally without any involvement of the ascending aorta or aortic valve. A Type B aortic dissection was confirmed. The decision was made at that time to treat the patient medically.
Soon after admission, the patient's creatinine began to rise from a baseline of 1.2 mg/dL (106.1 μmol/L) and peaked at 2.3 mg/dL (203.3 μmol/L) during the hospital stay. A bilateral renal ultrasound with doppler imaging revealed a right kidney measuring 10.2 cm with no arterial or venous flow identified. The left kidney measured 10.9 cm with both venous and arterial flow identified. Review of the CT scan confirmed that the patient had no perfusion of his right kidney at the time of presentation (Figures 1a and 1b). Since the patient had no history of renal dysfunction prior to this admission, he was thought to have suffered an infarction of his right kidney secondary to ischemia following aortic dissection. Further imaging by magnetic resonance angiogram (MRA) demonstrated no enhancement of the right renal artery with contrast. Without intervention, the patient's renal function recovered significantly to a level of 1.5 mg/dl (132.6 μmol/L) at the time of discharge.
In September 2002, the patient was found to have a serum creatinine of 15.2 mg/dl (1343.7 μmol/L) on routine follow up with his primary care physician. At the appointment, the patient complained of intermittent diffuse abdominal pain associated with eating and decreased per oral intake for ten days. The patient denied any urinary symptoms. He was subsequently admitted to our hospital for further evaluation of acute renal failure.
The patient's medical history consisted of hypertension for fourteen years, dyspepsia, erectile dysfunction, and appendectomy. Medications upon admission included losartan 100 mg PO QD, isosorbide dinitrate 20 mg PO TID, furosemide 20 mg PO BID, omeprazole 40 mg PO QD, metoprolol 150 md PO BID, and acetaminophen as needed. He denied tobacco use for 35 years, drank alcohol occasionally, and denied any illicit drug use. His family history was significant for two brothers with abdominal aortic aneurysms.
On physical exam, the patient was a thin pleasant, Caucasian male in no acute distress. He was afebrile, blood pressure 140/100, heart rate 70 beats per minute, respirations 20 times per minute with oxygen saturation of 94% on room air. Heart and lung exams were normal. Abdominal exam revealed positive bowel sounds, mild tenderness to palpation over the mid abdomen, no rebound, or guarding. No abdominal bruits were auscultated. He had 1+ radial, femoral and pedal pulse bilaterally with strength and sensation intact.
Significant laboratory data upon admission revealed a blood urea nitrogen of 98 mg/dL (35 μmol/L), a serum creatinine of 16.4 mg/dL (1449.8 μmol/L), a serum bicarbonate of 18 mmol/L, and a serum potassium of 4.7 mmol/L. Troponin I was normal and electrocardiogram showed normal sinus rhythm with 1st degree AV block. Serum hematocrit was 27.2% and peripheral smear showed no schistocytes. Urinalysis showed a specific gravity of 1.025, PH of 5.5, 30 mg/dl of protein, trace ketones, small LE. Urine sediment showed 1–2 granular casts per high powered field, 1–2 reticuloendothelial cells per high powered filed with too numerous to count red blood cells and white blood cells per high powered field.