Abstract/Text: Renal artery embolism was first described in 1940, but it is only recently becoming recognized as a clinically significant entity. Although relatively uncommon, it is clearly responsible for considerable morbidity in patients who experience it. The pathogenesis is typically related to cardiac thrombus formation with subsequent embolization, although other etiologies have been described. The authors present a case report followed by a review of the literature to highlight the clinical characteristics of this phenomena. Presentation, diagnostics, and treatment options will be reviewed with the aim of increasing awareness of renal artery embolism. As clinicians become more familiar with this condition, they will be more likely to consider it as a possible diagnosis in patients with a typical presentation. This will hopefully lead to improved care through prompt diagnosis and treatment, particularly as one treatment option may be time sensitive.

Abstract/Text: BACKGROUND: Acute renal infarction is an oft-missed diagnosis. As a result, its true incidence, although presumed to be low, is actually unknown. Surprisingly, the medical literature on the subject, other than anecdotal case reports, is scarce.
OBJECTIVES: To increase physician awareness of the diagnosis and to identify predictive clinical and laboratory features of the entity.
METHOD: Between 1 November 1997 and 31 October 2000, 11 cases of acute renal infarction in 10 patients were diagnosed in our center by contrast-enhanced computerized tomography. The medical charts of these patients were reviewed regarding risk factors, clinical presentation, possible predictive laboratory examinations, and outcome.
RESULTS: During the 36 month observation period, the incidence of acute renal infarction was 0.007%. The mean age of the patients (5 men and 5 women) was 67.4 +/- 21.1 (range 30-87 years). In four cases the right and in five the left kidney was involved; in the other two cases bilateral involvement was seen. In 7/10 patients, an increased risk for thromboembolic events was found. Six had chronic atrial fibrillation and one had a combined activated protein C resistance and protein S deficiency. Three patients had suffered a previous thromboembolic event. Two cases were receiving anticoagulant therapy with an INR of 1.6 and 1.8, respectively. On admission, flank pain was recorded in 10/11, fever in 5 and nausea/vomiting in 4 cases. Hematuria was detected in urine reagent strips in all cases. Serum lactate dehydrogenase and white blood cell count were elevated in all cases (1,570 +/- 703 IU/L and 12,988 +/- 3,841/microliter, respectively). In no case was the diagnosis of acute renal infarction initially entertained. The working diagnoses were renal colic in 2, pyelonephritis in 3, renal carcinoma, digitalis intoxication, and suspected endocarditis in one patient each, and an acute abdomen in 3. Time from admission to definitive CT diagnosis ranged from 24 hours to 6 days. Three patients were treated with intravenous heparin and another with a combination of i.v. heparin and renal intra-arterial urokinase infusion with, in the latter case, no recovery of function of the affected kidney. With the exception of this one patient (with a contralateral contracted kidney) who required maintenance dialysis, in all other cases serum creatinine levels remained unchanged or reverted to the baseline mean of 1.1 mg/dl (0.9-1.2).
CONCLUSIONS: Acute renal infarction is not as rare as previously assumed. The entity is often misdiagnosed. Unilateral flank pain in a patient with an increased risk for thromboembolism should raise the suspicion of renal infarction. In such a setting, hematuria, leucocytosis and an elevated LDH level are strongly supportive of the diagnosis.

Abstract/Text: Renal artery embolism was first described in 1940, but it is only recently becoming recognized as a clinically significant entity. Although relatively uncommon, it is clearly responsible for considerable morbidity in patients who experience it. The pathogenesis is typically related to cardiac thrombus formation with subsequent embolization, although other etiologies have been described. The authors present a case report followed by a review of the literature to highlight the clinical characteristics of this phenomena. Presentation, diagnostics, and treatment options will be reviewed with the aim of increasing awareness of renal artery embolism. As clinicians become more familiar with this condition, they will be more likely to consider it as a possible diagnosis in patients with a typical presentation. This will hopefully lead to improved care through prompt diagnosis and treatment, particularly as one treatment option may be time sensitive.

Abstract/Text: Severe aortic plaques seen on transesophageal echocardiography (TEE) are a high-risk cause of stroke and peripheral embolization. Evidence to guide therapy is lacking. Retrospective information was obtained regarding the occurrence of embolic events (stroke, transient ischemic attacks, or peripheral emboli) in 519 patients with severe thoracic aortic plaque seen on TEE since 1988. Treatment with statins, warfarin, or antiplatelet medications was noted. Treatment was not randomized. In a matched-paired analysis, each patient taking each class of therapy was matched for age, gender, previous embolic event, hypertension, diabetes, congestive failure, and atrial fibrillation to someone not taking that medication. Multivariate analysis was also performed. An embolic event occurred in 111 patients (21%). Multivariate analysis showed that statin use was independently protective against recurrent events (p = 0.0001). Matched analysis also showed a protective effect of statins (p = 0.0004; absolute risk reduction 17%, relative risk reduction 59%, number needed to treat [n = 6]). No protective effect was found for warfarin or antiplatelet drugs. The odds ratio for embolic events was 0.3 (95% confidence interval [CI] 0.2 to 0.6) for statin therapy, 0.7 (95% CI 0.4 to 1.2) for warfarin, and 1.4 (95% CI 0.8 to 2.4) for antiplatelet agents. Thus, there is a protective effect of statin therapy, and no significant benefit of warfarin or antiplatelet drugs on the incidence of stroke and other embolic events in patients with severe thoracic aortic plaque on TEE.