1/164. Gross hematuria of uncommon origin: the nutcracker syndrome.Left renal vein hypertension, also called "nutcracker phenomenon" or "nutcracker syndrome," is a rare vascular abnormality responsible for gross hematuria. The phenomenon is attributable to the idiopathic decrease in the angle between the aorta and the superior mesenteric artery with consequent compression of the left renal vein. The entrapment of the left renal vein is not easily detectable by ordinary diagnostic procedures. We report two cases of gross hematuria (persistent in one patient and recurrent in the other) caused by "nutcracker phenomenon." In both cases, no remarkable findings were obtained from medical history, urinary red blood cells morphology, repeated urinalysis, pyelography, cystoscopy, or ureteroscopy. Left renal vein dilation in one case was found with a computed tomography (CT) scan performed on the venous tree of left kidney. The diagnosis of "nutcracker phenomenon" was confirmed by renal venography with measurement of pressure gradient between left renal vein and inferior vena cava in both cases. In one case, the diagnosis was complicated by the presence of mycobacterium tuberculosis in urine. The "nutcracker phenomenon" is probably more common than thought. early diagnosis is important to avoid unnecessary diagnostic procedures and complications such as the thrombosis of the left renal vein. Many procedures are available to correct the compression of the left renal vein entrapped between the aorta and the superior mesenteric artery: Gortex graft vein interposition, nephropexy, stenting, and kidney autotransplantation. After surgery, gross hematuria ceases in almost all patients.- - - - - - - - - - ranking = 1keywords = kidney (Clic here for more details about this article) |
2/164. Solitary renal myofibromatosis: an unusual cause of infantile hypertension.INTRODUCTION: Renovascular disease accounts for the vast majority of cases of infantile hypertension with complications resulting from umbilical arterial catheterization predominating in the neonatal period and fibrodysplastic lesions of the renal artery predominating outside the neonatal period. We report a previously undescribed cause of renovascular hypertension: solitary renal myofibromatosis. CASE REPORT: A 9-month-old male infant was transported to the intensive care unit at Children's Hospital in Denver, colorado, for evaluation and treatment of a dilated cardiomyopathy and severe systemic hypertension. The child was full-term with no perinatal problems. Specifically, the child never required umbilical arterial catheterization. He was well until 6 months of age when his parents noted poor weight gain. At 9 months of age, he was evaluated at the referral hospital for failure to thrive. On examination he was noted to have a blood pressure of 170/110 mm Hg, but no other abnormalities. A chest radiograph showed cardiomegaly. Laboratory studies demonstrated normal electrolytes, blood urea nitrogen, and creatinine. However, urinalysis demonstrated 4 protein without red blood cells. An echocardiogram showed severe left ventricular dilatation with an ejection fraction of 16%. On admission the child was noted to be cachectic. His vital signs, including blood pressure, were normal for age. The physical examination was unremarkable. serum electrolytes, blood urea nitrogen, and creatinine were normal. Echocardiographic studies suggested a dilated hypertrophic cardiomyopathy. He was started on digoxin and captopril. Subsequently, he demonstrated episodic hypertension ranging from 170/90 to 220/130 mm Hg. A repeat echocardiogram 24 hours after admission demonstrated a purely hypertrophic cardiomyopathy. verapamil and nifedipine were added to the treatment regimen in an effort to better control the blood pressure without success. urine and blood for catecholamines and plasma renin activity, respectively, were sent and treatment with phentolamine instituted because of a possible pheochromocytoma. A spiral abdominal computerized tomographic scan revealed a markedly abnormal right kidney with linear streaky areas of calcification around the hilum and also an area of nonenhancement in the posterior upper pole. The adrenals and the left kidney were normal. Doppler ultrasound revealed a decrease in right renal arterial flow. The urinary catecholamines were normal and surgery was scheduled after the blood pressure was brought under control by medical treatment. At surgery, tumorous tissue and thrombosis of the renal artery were found in the right upper pole. A right nephrectomy was performed. Pathologic examination of the kidney showed the presence of a diffuse spindle cell proliferation in the interstitium of the kidney. The angiogenic/angiocentric character of the proliferation was demonstrated in several large renal vessels. The lumen of most vessels was narrowed and some vessels were totally occluded with recanalization and dystrophic calcifications observed. Immunostaining of the tumor demonstrated strong desmin and vimentin positivity and minimal actin positivity in the spindle cells. Mitotic activity was not noted in the spindle cell process. These pathologic changes were consistent with a diagnosis of infantile myofibromatosis (IM). The child's preoperative plasma renin activity was 50 712 ng/dL/h (reference range, 235-3700 ng/dL/h). DISCUSSION: The causes of systemic hypertension in infancy are many although renal causes are by far the most common. Renal arterial stenosis or thrombosis accounts for 10% to 24% of cases of infantile hypertension. renal artery thrombosis is usually a consequence of umbilical arterial catheterization, which can also lead to embolization of the renal artery. renal artery stenosis may result from fibrodysplastic lesions (74%), abdominal aortitis (9%), a complication of renal transplantation (5%), and ren- - - - - - - - - - ranking = 2keywords = kidney (Clic here for more details about this article) |
3/164. Radionuclide renography: a personal approach.Recent advances have increased the value of radionuclide renography in evaluating the patient with suspected disease of the genitourinary tract. The use of the consensus process to help standardize procedures and recommend interpretative criteria provides guidance for the nuclear medicine practitioner, serves as a basis to improve the standard of practice, and facilitates pooling of data from different centers. This review draws on the consensus criteria to present a personal approach to radionuclide renography with a particular emphasis on diuresis renography and the detection of renovascular hypertension. patients are encouraged to come well hydrated and void immediately prior to the study. Our standard radiopharmaceutical is 99mTc mercaptoacetyltriglycine (MAG3). Routine quantitative indices include a MAG3 clearance, whole kidney and cortical (parenchymal) regions of interest, measurements of relative uptake, time to peak height (Tmax), 20 min/max count ratio, residual urine volume and a T(1/2) in patients undergoing diuresis renography. A 1-minute image of the injection site is obtained at the conclusion of the study to check for infiltration because infiltration can invalidate a plasma sample clearance and alter the renogram curve. A postvoid image of the kidneys and bladder is obtained to calculate residual urine volume and to better evaluate drainage from the collecting system. In patients undergoing diuresis renography, the T(1/2) is calculated using a region of interest around the activity in the dilated collecting system. A prolonged T(1/2), however, should never be the sole criterion for diagnosing the presence of obstruction; the T(1/2) must be interpreted in the context of the sequential images, total and individual kidney function, other quantitative indices and available diagnostic studies. The goal of ACE inhibitor renography is to detect renovascular hypertension, not renal artery stenosis. patients with a positive study have a high probability of cure or amelioration of the hypertension following revascularization. In patients with azotemia or in patients with a small, poorly functioning kidney, the test result is often indeterminate (intermediate probability) with an abnormal baseline study that does not change following ACE inhibition. In patients with normal renal function, the test is highly accurate. To avoid unrealistic expectations on the part of the referring physician, it is often helpful to explain the likely differences in test results in these two-patient populations prior to the study.- - - - - - - - - - ranking = 2keywords = kidney (Clic here for more details about this article) |
4/164. Negative captopril renography on patients with renin mediated hypertension due to page kidney and reninoma.Through a mechanism similar to renal artery stenosis, patients with reninoma and page kidney also suffered from renin mediated hypertension. captopril renograms performed on our patients with the latter two conditions, however, did not yield diagnostic findings. Therefore, equivocal or negative captopril renography cannot serve to rule out conditions with elevated renin other than renal artery stenosis.- - - - - - - - - - ranking = 2.5keywords = kidney (Clic here for more details about this article) |
5/164. Autotransplantation and stent implantation for bilateral renal artery fibromuscular dysplasia.A 36-yr-old male was found to have renovascular hypertension due to an occluded right renal artery and 70% stenosis in the left renal artery, caused by fibromuscular dysplasia. The right kidney was supplied by collateral blood flow, and secreted more renin than the left kidney. Two differential therapeutic approaches were taken: autotransplantation for the right kidney and percutaneous transluminal renal angioplasty followed by stent implantation for the left. The renovascular hypertension was treated with these therapies, preserving renal function in this patient.- - - - - - - - - - ranking = 1.5keywords = kidney (Clic here for more details about this article) |
6/164. fibromuscular dysplasia: a rare cause of cilioretinal artery occlusion in childhood.OBJECTIVE: To report a case of cilioretinal artery occlusion with angiographic findings characteristic of the "string of beads" associated with renovascular hypertension secondary to fibromuscular dysplasia of the renal artery in a child. DESIGN: Case report. INTERVENTION: The patient underwent ex vivo renal artery reconstruction with saphenous vein graft and reimplantation. MAIN OUTCOME MEASURES: The main clinical outcomes were control of severe hypertension, reversible hypertensive retinopathy, and improvement of vision. RESULTS: Revascularization of the kidney improved renal function, and renovascular hypertension was clearly improved. visual acuity improved to 20/200. CONCLUSIONS: A child with hypertensive retinopathy and arterial occlusion in the retina should undergo investigation to rule out a surgically curable hypertension. magnetic resonance angiography of extrarenal vessels may reveal other sites of involvement of fibromuscular dysplasia. Evaluation and early diagnosis of renovascular hypertension will prevent severe end-organ damage.- - - - - - - - - - ranking = 0.5keywords = kidney (Clic here for more details about this article) |
7/164. Kawasaki disease complicated by renal artery stenosis.We report the case of a child who developed severe renovascular hypertension six months after acute Kawasaki disease. The hypertension was well controlled with enalapril, but there was a gradual decrease in function of the affected kidney. The lesion, an ostial stenosis of the right main renal artery, was not amenable to percutaneous balloon angioplasty, so was treated with bypass surgery. Vasculitis is an important cause of renovascular hypertension in children. This case highlights the importance of regular blood pressure monitoring in children with a history of systemic vasculitis.- - - - - - - - - - ranking = 0.5keywords = kidney (Clic here for more details about this article) |
8/164. hypertension due to renal artery occlusion in a patient with antiphospholipid syndrome.We report an unusual case of renovascular hypertension in a 16-year-old boy with primary antiphospholipid syndrome (PAPS), admitted to our clinic for severe drug-resistant hypertension and hypokalemia. Hormonal investigation revealed secondary aldosteronism and positive captopril test for renovascular disease. aortography confirmed the occlusion of the left renal artery. After nephrectomy, normalization of blood pressure and secondary aldosteronism occurred. Presently the patient remains in good health, receiving warfarin anticoagulant therapy. PAPS is defined by the presence of antiphospholipid antibodies and recurrent thrombosis. Arterial thrombosis (29%) appears to be less prevalent than venous thrombosis. Thrombotic microangiopathy of the kidney is frequently observed but renal artery occlusion, as seen in our patient, is unusual.- - - - - - - - - - ranking = 0.5keywords = kidney (Clic here for more details about this article) |
9/164. Repeated transient anuria following losartan administration in a patient with a solitary kidney.We report the case of a 70-year-old hypertensive man with a solitary kidney and chronic renal insufficiency who developed two episodes of transient anuria after losartan administration. He was hospitalized for a myocardial infarction with pulmonary edema, treated with high-dose diuretics. Due to severe systolic dysfunction losartan was prescribed. Surprisingly, the first dose of 50 mg of losartan resulted in a sudden anuria, which lasted eight hours despite high-dose furosemide and amine infusion. One week later, by mistake, losartan was prescribed again and after the second dose of 50 mg, the patient developed a second episode of transient anuria lasting 10 hours. During these two episodes, his blood pressure diminished but no severe hypotension was noted. Ultimately, an arteriography showed a 70-80% renal artery stenosis. In this patient, renal artery stenosis combined with heart failure and diuretic therapy certainly resulted in a strong activation of the renin-angiotensin system (RAS). Under such conditions, angiotensin ii receptor blockade by losartan probably induced a critical fall in glomerular filtration pressure. This case report highlights the fact that the angiotensin ii receptor antagonist losartan can cause serious unexpected complications in patients with renovascular disease and should be used with extreme caution in this setting.- - - - - - - - - - ranking = 2.5keywords = kidney (Clic here for more details about this article) |
10/164. Tc-99m-DTPA captopril renography in the detection of renovascular hypertension due to renal polar artery stenosis.A 24-year-old man whose clinical features were suggestive of renovascular hypertension was referred for captopril renal scintigraphy. captopril renal scintigraphy was positive for renovascular hypertension only when the left kidney was analyzed in 2 separate regions. Angiography confirmed severe stenosis (90%) in the upper branch of the left renal artery.- - - - - - - - - - ranking = 0.5keywords = kidney (Clic here for more details about this article) |
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