Radiology Page
Page Kidney A 16-year-old male presented to the emergency department with abdominal pain and was found to have an elevated blood pressure of 174/100 mm Hg. He gave a history of injury to the left flank while playing football 2 weeks prior to presentation. Subsequent laboratory analyses revealed an elevated potassium of 5.1 mEq/l. The remaining laboratory values were within normal limits, including hemoglobin and hematocrit at 15.1 gm/dl and 42.9%, respectively. Renal ultrasound showed a large left subcapsular debris filled hypoechoic collection with a mass effect on the left kidney (fig. 1). Doppler evaluation demonstrated increased resistive indexes ranging from 0.73 to 0.85 in the main left renal artery and intrarenal branches. Subsequent abdominal contrast enhanced computerized tomography (CT) confirmed a left renal subcapsular hematoma (fig. 2). Imaging findings in association with hypertension led to the diagnosis of Page kidney. The term Page kidney originated in 1939 when Dr. Irvine Page performed an experiment in which he wrapped the kidneys of dogs in cellophane.1 He observed changes of perinephritis within 3 to 5 days and hypertension development within 4 to 5 weeks.2 Page subsequently replicated his findings in a cat and a rabbit.2 A similar result can be observed in instances of subcapsular hematoma in which the resultant induction of perinephritis and parenchymal compression gives rise to hypertension secondary to increased renin levels.1 External compression by the subcapsular hematoma activates the renin-angiotensin system via renal and subsequent vascular ischemic changes.1,3 A similar finding was described by Goldblatt a few years earlier when he experimented with ligating or constricting renal artery induced hypertension.3 Page later described a case report of a young male football player who experienced acute hypertensive changes after he was found to have a subcapsular hematoma.4 In this individual blood pressure returned to normal following nephrectomy. There have been several reports of Page kidney throughout the literature. Similarities among
0022-5347/15/1944-1109/0 THE JOURNAL OF UROLOGY® Ó 2015 by AMERICAN UROLOGICAL ASSOCIATION EDUCATION
AND
RESEARCH, INC.
published cases include a younger male predominance with a median age of 38 years.4 Average blood pressure at diagnosis is 177/95 mm Hg. The majority of published cases were the result of sports induced trauma, although an increasing number of recently published cases occurred in instances of motor vehicle accidents and renal allografts. The incidence of Page kidney as a complication of renal transplantation is low with a reported frequency of 1%.4 Regardless of the cause, the mechanism remains the same in the myriad cases. Nephrectomy has been the treatment of choice. However, more recently less invasive treatments have become more favorable, including percutaneous drainage.5 Medical management is used as an adjunct or as a sole treatment option on a case specific basis. Hypertension has been shown to resolve in most cases after surgical drainage of the fluid collection or often after spontaneous resolution.6
Figure 1. Transverse grayscale ultrasound shows mildly heterogeneous hypoechoic, subcapsular fluid collection (long arrows) surrounding left kidney with mass effect on kidney (short arrow).
http://dx.doi.org/10.1016/j.juro.2015.07.035 Vol. 194, 1109-1110, October 2015 Printed in U.S.A.
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RADIOLOGY PAGE
Figure 2. Axial (A) and coronal (B) contrast enhanced CT reveals large left renal subcapsular hematoma (arrows) displacing and compressing left kidney.
CT of the abdomen is the preferred modality to diagnose subcapsular renal hematoma. It will demonstrate a subcapsular fluid collection of varying density depending on the nature and age of the collection.3 There will also be deformation of the adjacent kidney (fig. 2). Elevated arterial resistive indexes on renal vascular ultrasound contribute convincing evidence of vascular compromise and favor the diagnosis of Page kidney. Magnetic resonance imaging (MRI) and renal arteriography are performed less often. However, MRI is more sensitive to the stage of blood product degradation and, therefore, to the age of a subcapsular hematoma.3 Renal arteriography is invasive and less sensitive than CT or MRI. Demonstration of a subcapsular renal fluid collection is not diagnostic of Page kidney unless the patient has well documented hypertension. This patient was initially treated with medical therapy alone, including lisinopril and amlodipine, which provided adequate blood pressure control. Followup CT approximately 1 month later revealed no change in the subcapsular hematoma. Therefore, ultrasound guided drainage of the hematoma was
performed and approximately 1 L of brown thin fluid was aspirated. The fluid collection recurred after percutaneous drainage and the patient is currently being evaluated for more definitive therapy. Matthew Kiczek and Unni Udayasankar Cleveland Clinic Children’s Hospital Cleveland Ohio 1. Smyth A, Collins CS, Thorsteinsdottir B et al: Page kidney: etiology, renal function outcomes, and risk for future hypertension. J Clin Hypertens 2012; 14: 216. 2. Scott PL, Yune HY and Weinberger MH: Page kidney: an unusual cause of hypertension. Radiology 1976; 119: 547. 3. Hayday A, Bakri RS, Prim M et al: Page kidney: a review of the literature. J Nephrol 2003; 16: 329. 4. Dopson SJ, Jayakumar S and Velez JCQ: Page kidney as a rare cause of hypertension: case report and review of the literature. Am J Kid Dis 2009; 54: 334. 5. Myrianthefs P, Aravosita P, Tokta R et al: Resolution of page kidney-related hypertension with medical therapy: a case report. Heart Lung 2007; 36: 377. 6. Sterns RH, Rabinowitz R, Segal AJ et al: ’Page kidney’ hypertension caused by chronic subcapsular hematoma. Arch Intern Med 1985; 145: 169.
Page Kidney A 16-year-old male presented to the emergency department with abdominal pain and was found to have an elevated blood pressure of 174/100 mm Hg. He gave a history of injury to the left flank while playing football 2 weeks prior to presentation. Subsequent laboratory analyses revealed an elevated potassium of 5.1 mEq/l. The remaining laboratory values were within normal limits, including hemoglobin and hematocrit at 15.1 gm/dl and 42.9%, respectively. Renal ultrasound showed a large left subcapsular debris filled hypoechoic collection with a mass effect on the left kidney (fig. 1). Doppler evaluation demonstrated increased resistive indexes ranging from 0.73 to 0.85 in the main left renal artery and intrarenal branches. Subsequent abdominal contrast enhanced computerized tomography (CT) confirmed a left renal subcapsular hematoma (fig. 2). Imaging findings in association with hypertension led to the diagnosis of Page kidney. The term Page kidney originated in 1939 when Dr. Irvine Page performed an experiment in which he wrapped the kidneys of dogs in cellophane.1 He observed changes of perinephritis within 3 to 5 days and hypertension development within 4 to 5 weeks.2 Page subsequently replicated his findings in a cat and a rabbit.2 A similar result can be observed in instances of subcapsular hematoma in which the resultant induction of perinephritis and parenchymal compression gives rise to hypertension secondary to increased renin levels.1 External compression by the subcapsular hematoma activates the renin-angiotensin system via renal and subsequent vascular ischemic changes.1,3 A similar finding was described by Goldblatt a few years earlier when he experimented with ligating or constricting renal artery induced hypertension.3 Page later described a case report of a young male football player who experienced acute hypertensive changes after he was found to have a subcapsular hematoma.4 In this individual blood pressure returned to normal following nephrectomy. There have been several reports of Page kidney throughout the literature. Similarities among
0022-5347/15/1944-1109/0 THE JOURNAL OF UROLOGY® Ó 2015 by AMERICAN UROLOGICAL ASSOCIATION EDUCATION
AND
RESEARCH, INC.
published cases include a younger male predominance with a median age of 38 years.4 Average blood pressure at diagnosis is 177/95 mm Hg. The majority of published cases were the result of sports induced trauma, although an increasing number of recently published cases occurred in instances of motor vehicle accidents and renal allografts. The incidence of Page kidney as a complication of renal transplantation is low with a reported frequency of 1%.4 Regardless of the cause, the mechanism remains the same in the myriad cases. Nephrectomy has been the treatment of choice. However, more recently less invasive treatments have become more favorable, including percutaneous drainage.5 Medical management is used as an adjunct or as a sole treatment option on a case specific basis. Hypertension has been shown to resolve in most cases after surgical drainage of the fluid collection or often after spontaneous resolution.6
Figure 1. Transverse grayscale ultrasound shows mildly heterogeneous hypoechoic, subcapsular fluid collection (long arrows) surrounding left kidney with mass effect on kidney (short arrow).
http://dx.doi.org/10.1016/j.juro.2015.07.035 Vol. 194, 1109-1110, October 2015 Printed in U.S.A.
www.jurology.com
j
1109
1110
RADIOLOGY PAGE
Figure 2. Axial (A) and coronal (B) contrast enhanced CT reveals large left renal subcapsular hematoma (arrows) displacing and compressing left kidney.
CT of the abdomen is the preferred modality to diagnose subcapsular renal hematoma. It will demonstrate a subcapsular fluid collection of varying density depending on the nature and age of the collection.3 There will also be deformation of the adjacent kidney (fig. 2). Elevated arterial resistive indexes on renal vascular ultrasound contribute convincing evidence of vascular compromise and favor the diagnosis of Page kidney. Magnetic resonance imaging (MRI) and renal arteriography are performed less often. However, MRI is more sensitive to the stage of blood product degradation and, therefore, to the age of a subcapsular hematoma.3 Renal arteriography is invasive and less sensitive than CT or MRI. Demonstration of a subcapsular renal fluid collection is not diagnostic of Page kidney unless the patient has well documented hypertension. This patient was initially treated with medical therapy alone, including lisinopril and amlodipine, which provided adequate blood pressure control. Followup CT approximately 1 month later revealed no change in the subcapsular hematoma. Therefore, ultrasound guided drainage of the hematoma was
performed and approximately 1 L of brown thin fluid was aspirated. The fluid collection recurred after percutaneous drainage and the patient is currently being evaluated for more definitive therapy. Matthew Kiczek and Unni Udayasankar Cleveland Clinic Children’s Hospital Cleveland Ohio 1. Smyth A, Collins CS, Thorsteinsdottir B et al: Page kidney: etiology, renal function outcomes, and risk for future hypertension. J Clin Hypertens 2012; 14: 216. 2. Scott PL, Yune HY and Weinberger MH: Page kidney: an unusual cause of hypertension. Radiology 1976; 119: 547. 3. Hayday A, Bakri RS, Prim M et al: Page kidney: a review of the literature. J Nephrol 2003; 16: 329. 4. Dopson SJ, Jayakumar S and Velez JCQ: Page kidney as a rare cause of hypertension: case report and review of the literature. Am J Kid Dis 2009; 54: 334. 5. Myrianthefs P, Aravosita P, Tokta R et al: Resolution of page kidney-related hypertension with medical therapy: a case report. Heart Lung 2007; 36: 377. 6. Sterns RH, Rabinowitz R, Segal AJ et al: ’Page kidney’ hypertension caused by chronic subcapsular hematoma. Arch Intern Med 1985; 145: 169.
