Atheroembolic renal disease

Cholesterol Embolic Renal Disease: Experience of a Large Healthcare System

Context. To determine the clinical-pathological features associated with cholesterol embolic renal disease, and review of literature. Design. This retrospective case series includes patients with cholesterol embolic renal disease (10 of 3087 kidney biopsies) who were diagnosed at Northwell Health, New York, between July 2017 and October 2022. Results. Cholesterol embolic renal disease is a rare disease with a prevalence of 0.32%. Four of 10 patients had intravascular interventional radiology procedures within 6 months prior to kidney biopsy. Four patients had remote interventional radiology history (6 months to 4 years). Seven patients presented with acute kidney injury; 3 patients underwent renal biopsy due to proteinuria. The average baseline creatinine was 2.0 ± 0.9 mg/dL; the creatinine at kidney biopsy and at follow-up was 4.3 ± 3.0 mg/dL and 2.8 ± 1.3 mg/dL, respectively. Eight patients had elevated serum eosinophil counts. Three patients died (mortality rate 30%) in an average follow-up of 4 months (range: 1-10 months). One patient progressed to end-stage kidney disease. The presence of cholesterol clefts is a hallmark of atherosclerotic emboli. Cholesterol clefts were present on the specimen for light microscopy (H&E and special stains) in 9 biopsies; 7 patients had cholesterol clefts in vascular lumens and/or walls. Cholesterol clefts were present on semi-thin sections for electron microscopy examination in 4 biopsies. One patient had cholesterol clefts present in semi-thin sections only. Conclusions. The clinical manifestation of cholesterol embolic renal disease in patients without recent intravascular interventional radiology history can be indolent but is associated with high mortality. Careful examination of all levels with light microscopy, including the perirenal tissue, and semi-thin sections can increase the detection rate of cholesterol embolic renal disease.

Cardiac Surgery-Associated Acute Kidney Injury

AKI is a common and serious complication of cardiac surgery that has a significant impact on patient morbidity and mortality. The Kidney Disease Improving Global Outcomes definition of AKI is widely used to classify and identify AKI associated with cardiac surgery (cardiac surgery-associated AKI [CSA-AKI]) on the basis of changes in serum creatinine and/or urine output. There are various preoperative, intraoperative, and postoperative risk factors for the development of CSA-AKI which should be recognized and addressed as early as possible to expedite its diagnosis, reduce its occurrence, and prevent or ameliorate its devastating complications. Crucial issues are the inaccuracy of serum creatinine as a surrogate parameter of kidney function in the perioperative setting of cardiothoracic surgery and the necessity to discover more representative markers of the pathophysiology of AKI. However, except for the tissue inhibitor of metalloproteinase-2 and insulin-like growth factor binding protein 7 ratio, other diagnostic biomarkers with an acceptable sensitivity and specificity are still lacking. This article provides a comprehensive review of various aspects of CSA-AKI, including pathogenesis, risk factors, diagnosis, biomarkers, classification, prevention, and treatment management.

Acute Kidney Injury Management Strategies Peri-Cardiovascular Interventions

In many countries, the aging population and the higher incidence of comorbid conditions have resulted in an ever-growing need for cardiac interventions. Acute kidney injury (AKI) is a common complication of these interventions, associated with higher mortalities, chronic or end-stage kidney disease, readmission rates, and hospital and post-discharge costs. The AKI pathophysiology includes contrast-associated AKI, hemodynamic changes, cardiorenal syndrome, and atheroembolism. Preventive measures include limiting contrast media dose, optimizing hemodynamic conditions, and limiting exposure to other nephrotoxins. This review article outlines the current state-of-art knowledge regarding AKI pathophysiology, risk factors, preventive measures, and management strategies in the peri-interventional period.

Formation and Cellular Impact of Cholesterol Crystals in Health and Disease

Cholesterol crystals (CCs) were first discovered in atherosclerotic plaque tissue in the early 1900 and have since been observed and implicated in many diseases and conditions, including myocardial infarction, abdominal aortic aneurism, kidney disease, ocular diseases, and even central nervous system anomalies. Despite the widespread involvement of CCs in many pathologies, the mechanisms involved in their formation and their role in various diseases are still not fully understood. Current knowledge concerning the formation of CCs, as well as the molecular pathways activated upon cellular exposure to CCs, will be explored in this review. As CC formation is tightly associated with lipid metabolism, the role of cellular lipid homeostasis in the formation of CCs is highlighted, including the role of lysosomes. In addition, cellular pathways and processes known to be affected by CCs are described. In particular, CC-induced activation of the inflammasome and production of reactive oxygen species, along with the role of CCs in complement-mediated inflammation is discussed. Moreover, the clinical manifestation of embolized CCs is described with a focus on renal and skin diseases associated with CC embolism. Lastly, potential therapeutic measures that target either the formation of CCs or their impact on different cell types and tissues are highlighted.

Cholesterol Embolization Syndrome After Kidney Transplantation: A Case Series and Systematic Review

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Background.

Cholesterol embolization syndrome (CES) is an uncommon but well-known cause of renal failure in native kidneys, but little is known about CES in kidney transplant recipients. The aim of this study was to determine the incidence, clinical characteristics, histopathology, and prognosis of CES after kidney transplantation.

Methods.

CES cases in both transplanted and native kidneys (control group) were identified by searching the databases of the divisions of Nephrology and Pathology of our institution. Clinical data were retrospectively collected. Biopsies were classified according to the latest Banff 2019 Update. Second, a systematic literature search was performed (December 01, 2020) of Ovid MEDLINE, EMBASE, the Cochrane Central Register of controlled trials, Google Scholar, and Web of Science.

Results.

CES was observed in for-cause biopsies of 11 out of 2350 (0.47%) kidney transplant recipients transplanted between January 1, 2006, and December 31, 2018 (0.0009 cases per person-year). All patients had ≥1 cardiovascular risk factor, and 9 donors were expanded criteria donors. Graft loss occurred in 27.3% of the patients diagnosed with CES. Eight transplant biopsies with CES were also classified as biopsy-proven acute rejection. Transplant biopsies showed signs of inflammation (arteritis, n = 7; interstitial inflammation, n = 5; tubulitis, n = 7). One patient with CES in a native kidney was identified. The biopsy of the native kidney only showed arteritis and classified as an isolated “v” lesion. The literature search resulted in 188 unique articles of which 20 were included. A total of 47 cases of CES after kidney transplantation was reported. Cholesterol emboli were found in <1% of all kidney transplant biopsies. In 57.8% of the kidney transplant biopsies with CES described in literature, concomitant inflammation was present.

Conclusions.

CES is an uncommon cause of kidney transplant failure, although the incidence of CES may be underestimated. CES may mimic rejection as it can be accompanied by arteritis.

Ischemic small bowel perforation caused by cholesterol crystal embolism following transcatheter arterial chemoembolization for recurrent hepatocellular carcinoma: a case report

Background

Cholesterol crystal embolism (CCE) following transcatheter arterial chemoembolization (TACE) is rare.

Case presentation

A 71-year-old man underwent TACE for recurrence of hepatocellular carcinoma (HCC). On postoperative day (POD) 5, he developed abdominal pain and fever. Computed tomography revealed intraperitoneal free air. The patient was diagnosed with gastrointestinal perforation with peritonitis, for which partial intestinal resection and covering ileostomy were performed. Histological examination revealed perforation of the small intestine caused by CCE. The patient made a satisfactory recovery and was discharged on POD 30. The patient showed no recurrence of cholesterol crystal embolism or HCC for 2 years after surgery.

Conclusion

We reported a successfully treated case of ischemic small bowel perforation due to cholesterol crystal embolism following transcatheter arterial chemoembolization for recurrent HCC.

Higher cardiovascular mortality in men with persistent dipstick hematuria

BACKGROUND

We previously reported that dipstick hematuria (UH) was associated with higher all-cause mortality in men, but not in women. We extended the observation and examined the causes of death using repeated urinalysis in men.

METHODS

Subjects were those who participated the Tokutei-Kenshin between 2008 to 2015 in seven districts. Using National database of death certificate, we identified those who might have died and confirmed further with the collaborations of the regional National Health Insurance agency and public health nurses. Dipstick results of 1 + and higher were defined as hematuria. Hazard ratio (HR) and 95% confidence interval (CI) were calculated using the Cox proportional hazard analysis. We adjusted for age, body mass index, eGFR, proteinuria, comorbid condition (diabetes mellitus, hypertension, and dyslipidemia), past history (stroke, heart disease, and kidney disease), and lifestyle (smoking, drinking, walking, and exercise).

RESULTS

A total of 170,119 men were studied and 70,350 (41.4% of the total) were re-examined next year. The prevalence of UH (-/-), UH (-/+), UH (±), and UH (+ /+) was 77.2% (N = 54,298), 14.0% (N = 9,838), 1.4% (N = 1014) and 7.4% (N = 5,200), respectively. We identified 1,162 deaths (1.7% of the total of the re-examined). The adjusted HR (95% CI) was 1.49 (1.22-1.81) for all-cause mortality and 1.83 (1.23-2.71) for cardiovascular death compared to those with UH (-/-), respectively. However, that for cancer mortality risk was not significant: 1.23 (0.92-1.64).

CONCLUSIONS

In men, persistent dipstick hematuria is a significantly risk factor of all-cause mortality, in particular cardiovascular death among general screening participants.

Atheroembolic Renal Disease: A Case Series

Atheroembolic renal disease (AERD), a part of systemic cholesterol embolization syndrome, is caused by the occlusion of small arteries in the kidneys by cholesterol crystal emboli from ulcerated atherosclerotic plaques. Kidney is commonly involved because of its proximity to the abdominal aorta and its enormous blood supply. AERD is an under diagnosed condition. We report eight cases of AERD, highlighting the variability in its clinical presentation and the importance of a renal biopsy to arrive at a definitive diagnosis.

Association of dipstick hematuria with all-cause mortality in the general population: results from the specific health check and guidance program in Japan

Background

Dipstick urine tests are used for general health screening in Japan. The effects of this screening on mortality have not been examined, especially with regard to hematuria.

Methods

Subjects were those who participated in the 2008 Tokutei-Kenshin (nationwide specific health check and guidance program) in six districts in Japan. Using the national database of death certificates from 2008 to 2012, we identified subjects who might have died. We verified the candidates in collaboration with the regional National Health Insurance agency and public health nurses. Data were released to the research team supported by the Ministry of Health, Labor, and Welfare of Japan. Dipstick results of 1+ and higher were defined as hematuria (+). Hazard ratio (HR) [95% confidence interval (CI)] was calculated using the Cox proportional hazard analysis.

Results

Among 112 115 subjects, we identified that 1290 had died by the end of 2012. In hematuria (-) subjects, the crude mortality rates were 1.2% (1.8% in men, 0.7% in women), whereas in hematuria (+) subjects, they were 1.1% (2.9% in men, 0.7% in women). After adjusting for age, body mass index, estimated glomerular filtration rate, proteinuria, comorbid condition (diabetes mellitus, hypertension and dyslipidemia), past history (stroke, heart disease and kidney disease) and lifestyle (smoking, drinking, walking and exercise), the HR (95% CI) for dipstick hematuria (+) in men was 1.464 (1.147-1.846; P = 0.003), whereas that for hematuria (-) was 0.820 (0.617-1.073; P = 0.151).

Conclusions

Dipstick hematuria is significantly associated with mortality in men among Japanese community-based screening participants.

Renal cholesterol crystal embolism in the setting of warfarin use

A 73-year-old man presented for evaluation of weakness and black tarry stools that occurred 1 day prior to admission. His medical history is significant for diabetes mellitus, stage 3 chronic kidney disease and deep vein thrombosis on warfarin. He was admitted to the hospital and was found to have acute kidney injury and gastrointestinal bleeding due to a supratherapeutic International Normalized Ratio. His hospital course was complicated by persistent decline in his renal function. He was given intravenous fluid resuscitation, fresh frozen plasma and packed red blood cells for his acute blood loss anaemia. Urinalysis was consistent with acute tubular necrosis. Given the persistent rise in creatinine, a kidney biopsy was obtained, and was significant for mild inflammatory changes, without evidence of vasculitis or allergic interstitial nephritis. Histopathological examination with tissue fixation revealed cholesterol embolisation. Given that he had no recent endovascular procedure or instrumentation, this atheroembolic event was attributed to his warfarin use.

Cholesterol-embolization syndrome: current perspectives

Cholesterol-embolization syndrome (CES) is a multisystemic disease with various clinical manifestations. CES is caused by embolization of cholesterol crystals (CCs) from atherosclerotic plaques located in the major arteries, and is induced mostly iatrogenically by interventional and surgical procedures; however, it may also occur spontaneously. Embolized CCs lead to both ischemic and inflammatory damage to the target organ. Therefore, anti-inflammatory agents, such as corticosteroids and cyclophosphamide, have been investigated as treatment for CES in several studies, with conflicting results. Recent research has revealed that CES is actually a kind of autoinflammatory disease in which inflammasome pathways, such as NLRP3 and IL1, are induced by CCs. These recent findings may have clinical implications such that colchicine and IL1 inhibitors, namely canakinumab, may be beneficial in the early stages of CES.

An atypical presentation of a severe and massive atheroembolic disease

Atheroembolic renal disease (AERD) is a kidney manifestation of atherosclerosis as a systemic disease. AERD is defined as a renal impairment secondary to embolization of cholesterol crystals with consequent occlusion of renal vascularization. The current case report describes one patient with multiple risk factors but without any inciting event history who presents a very atypical clinical course of a severe and massive atheroembolic disease that developed spontaneously and silently.

Cholesterol Crystal Embolism and Chronic Kidney Disease

Renal disease caused by cholesterol crystal embolism (CCE) occurs when cholesterol crystals become lodged in small renal arteries after small pieces of atheromatous plaques break off from the aorta or renal arteries and shower the downstream vascular bed. CCE is a multisystemic disease but kidneys are particularly vulnerable to atheroembolic disease, which can cause an acute, subacute, or chronic decline in renal function. This life-threatening disease may be underdiagnosed and overlooked as a cause of chronic kidney disease (CKD) among patients with advanced atherosclerosis. CCE can result from vascular surgery, angiography, or administration of anticoagulants. Atheroembolic renal disease has various clinical features that resemble those found in other kidney disorders and systemic diseases. It is commonly misdiagnosed in clinic, but confirmed by characteristic renal biopsy findings. Therapeutic options are limited, and prognosis is considered to be poor. Expanding knowledge of atheroembolic renal disease due to CCE opens perspectives for recognition, diagnosis, and treatment of this cause of progressive renal insufficiency.

Atheromatous embolization

Atheromatous embolization is a multisystem disease complicating advanced atherosclerosis. It occurs most often as a complication of angiography, an endovascular procedure or cardiovascular surgery. Atheromatous embolization can present in a subtle manner where it is often under-recognized, or with catastrophic results including myocardial infarction, strake or acute renal failure. It may mimic other disease processes and often goes underdiagnosed and undertreated. A high clinical suspicion is the key to diagnosis. Atheromatous embolization results in significant morbidity and mortality; therefore, early recognition followed by aggressive management may help to prevent end-organ damage and improve overall clinical outcomes. Management strategies should include risk factor modification, prevention of further insults by discontinuing or avoiding predisposing factors, supportive treatment and interventional or surgical approaches to remove the atheroembolic source. Atheromatous embolization is expected to increase as our population ages and the epidemics of diabetes mellitus and obesity increase.

Radiocontrast-Induced Acute Renal Failure

The intravascular administration of iodinated radiocontrast media can lead to acute renal dysfunction. Even small changes in renal function have been associated with increased morbidity and mortality, making the prevention of radiocontrast nephropathy of paramount importance. This review summarizes the principal risk factors for radiocontrast nephropathy and evidence-based preventive strategies that should be used to limit its occurrence. Risk factors for radiocontrast nephropathy include preexistent kidney disease, diabetes mellitus, dose of radiocontrast used, advanced congestive heart failure, and intravascular volume depletion. Proven preventive measures include volume expansion with intravenous saline or sodium bicarbonate and the use of low-osmolar or iso-osmolar radiocontrast media. Studies evaluating N-acetylcysteine have been conflicting, with meta-analyses suggesting a small beneficial effect. Studies of other pharmacologic agents have not demonstrated clinical benefit.

Contrast-induced Acute Kidney Injury

Because of the increased use of contrast media, the potential risk of contrast-induced acute kidney injury (CIAKI) has also increased. CIAKI often results in chronic kidney disease (CKD), an affliction with increasing incidence in modern society. The current prevalence of CIAKI is difficult to estimate because most victims are asymptomatic. The first Japanese guidelines regarding contrast agent examinations were recently announced, but their only recommendation is to provide classic fluid replacement with saline 6-12 h before and after the contrast procedure. According to a review summarizing the recent literature, little evidence supports this suggestion. To obtain early diagnoses and to treat emergent patients, it is appropriate to perform procedures using contrast media without knowledge of patients' renal function. Prevention of CIAKI is the most important consideration, and the usefulness of risk scores predicting the development of CIAKI has been reported. However, no prospective studies have been performed to date, and, therefore, such studies will be necessary in the future. Furthermore, the development of novel preventative interventions for CIAKI is also required.

A Study of Relationship of Atheroembolic Risk Factors with Postoperative Recovery in Renal Function after Partial Nephrectomy in Patients Staged T1-2 Renal Cell Carcinoma during Median 4-Year Follow-up

Purpose

The objective of this study is to evaluate the relationship of atheroembolic risk factors with postoperative recovery of renal function after on-clamp partial nephrectomy (PN) with warm ischemia in patients with staged T1-2 renal cell carcinoma (RCC).

Materials and Methods

A total of 234 patients from 2004 to 2012 were included, and their clinicopathologic and operative parameters, including atheroembolic risk factors were reviewed retrospectively. Renal function, as determined by estimated glomerular filtration rate (eGFR) and measurement of serum creatinine level (Cr) at each scheduled follow-up for a median four years, was compared between the high-risk (HR) group (n=49, ≥ five risk factors) and the low-risk (LR) group (n=185, < five risk factors).

Results

Except for baseline renal function and number of risk factors for atheroembolism, differences in characteristics between groups were comparatively insignificant. At 3 months after the operation, Cr and eGFR differed significantly between the two groups (p < 0.05), but no differences were observed afterward. Significant deterioration from baseline in Cr and eGFR was observed in both groups at 1 month after the operation, with a greater change in the HR group (p < 0.05). From measurement to measurement, significantly faster deterioration in Cr and eGFR was observed in the HR group than in the LR group until 6 months after the operation (Cr: LR, 0.02 mg/dL and HR, 0.13 mg/dL; eGFR: LR, 1.50 mL/min/1.73 m² and HR, 6.38 mL/min/1.73 m²; p < 0.05).

Conclusion

The presence of atheroembolic risk factors may negatively influence postoperative recovery of renal function after PN in patients with localized RCC.

Autopsy Renal Pathology

We provide an overview of assessment of the kidneys at autopsy, with special considerations for pediatric versus adult kidneys. We describe the approach to gross examination, tissue allocation when needed for additional studies of potential medical renal disease, the spectrum of congenital abnormalities of the kidneys and urinary tract, and approach to cystic diseases of the kidney. We also discuss common lesions seen at autopsy, including acute tubular injury, ischemic versus toxic contributions to this injury, interstitial nephritis, and common vascular diseases. Infections commonly involve the kidney at autopsy, and the key features and differential diagnoses are also discussed.

Non-coronary atherosclerosis

During the last decades, the clinical and research interest in atherosclerosis has been mostly focused on coronary arteries. After the publications of the European Society Guidelines and AHA/ACC Guidelines on Peripheral artery diseases, and of the Registry REduction in Atherothrombosis for Continued Health Registry, there has been an increased interest in atherosclerosis of the lower extremity arteries and its presence in multifocal disease. However, awareness in the general population and the medical community of non-coronary artery diseases, and of its major prognostic implications remain relatively low. The aim of this general review stemming out of an ESC Working Group on Peripheral Circulation meeting in 2011 is to enhance awareness of this complex disease highlighting the importance of the involvement of atherosclerosis at different levels with respect to clinical presentation, diagnosis, and co-existence of the disease in the distinct arterial territories. We also emphasize the need of an interdisciplinary approach to face the broad and complex spectrum of multifocal disease, and try to propose a series of tentative recommendations and measures to be implemented in non-coronary atherosclerosis.

Favorable outcome in atheroembolic renal disease with pulse steroid therapy

Atheroembolic renal disease is characterized by renal failure secondary to occlusion of renal vasculature by cholesterol containing atheromatous plaques. Clinical presentations of this disease entity are myriad, with limited therapeutic options and unfavorable outcomes. This report describes an elderly male patient with peripheral vascular disease who developed acute renal failure during hospital admission for rectal bleed, and was diagnosed with atheroembolic renal disease on renal biopsy. The patient was managed with pulse steroid therapy and had a favorable outcome.

A patient with idiopathic cholesterol crystal embolization: effectiveness of early detection and treatment

A 72-year-old man was admitted to our hospital because of progressive renal dysfunction persisting for 1.5 months. Physical examination showed livedo reticularis of the toes of both feet, peripheral edema, and gait disturbance due to the toe pain. The levels of blood urea nitrogen (50.0 mg/dL) and creatinine (2.81 mg/dL) were elevated, and eosinophilia (10%, 870/µL) was noted. A biopsy of the area of livedo reticularis revealed cholesterin crystals. The patient had not undergone angiography, anticoagulation therapy, or antithrombotic treatment. Idiopathic cholesterol crystal embolization was diagnosed. Transesophageal echocardiography revealed intimal thickening of the aorta and plaque. Oral steroid therapy was started because of the progressive renal dysfunction. After steroid therapy, the symptoms improved. Early diagnosis and treatment are important. Renal dysfunction is a common symptom in elderly patients. Cholesterol crystal embolization should also be considered as a cause of unexplained renal dysfunction, especially in such patients.

Contrast-induced nephropathy in interventional cardiology

Development of contrast-induced nephropathy (CIN), ie, a rise in serum creatinine by either ≥0.5 mg/dL or by ≥25% from baseline within the first 2-3 days after contrast administration, is strongly associated with both increased inhospital and late morbidity and mortality after invasive cardiac procedures. The prevention of CIN is critical if long-term outcomes are to be optimized after percutaneous coronary intervention. The prevalence of CIN in patients receiving contrast varies markedly (from <1% to 50%), depending on the presence of well characterized risk factors, the most important of which are baseline chronic renal insufficiency and diabetes mellitus. Other risk factors include advanced age, anemia, left ventricular dysfunction, dehydration, hypotension, renal transplant, low serum albumin, concomitant use of nephrotoxins, and the volume of contrast agent. The pathophysiology of CIN is likely to be multifactorial, including direct cytotoxicity, apoptosis, disturbances in intrarenal hemodynamics, and immune mechanisms. Few strategies have been shown to be effective to prevent CIN beyond hydration, the goal of which is to establish brisk diuresis prior to contrast administration, and to avoid hypotension. New strategies of controlled hydration and diuresis are promising. Studies are mixed on whether prophylactic oral N-acetylcysteine reduces the incidence of CIN, although its use is generally recommended, given its low cost and favorable side effect profile. Agents which have been shown to be ineffective or harmful, or for which data supporting routine use do not exist, include fenoldopam, theophylline, dopamine, calcium channel blockers, prostaglandin E(1), atrial natriuretic peptide, statins, and angiotensin-converting enzyme inhibitors.

Renal function recovery in chronic dialysis patients

Renal function recovery (RFR) from acute kidney injury requiring dialysis occurs at a high frequency. RFR from chronic dialysis, on the other hand, is an uncommon but well-recognized phenomenon, occurring at a rate of 1.0-2.4% according to data from large observational studies. The underlying etiology of renal failure is the single most important predicting factor of RFR in chronic dialysis patients. The disease types with the highest RFR rates are atheroembolic renal disease, systemic autoimmune disease, renovascular diseases, and scleroderma. The disease types with the lowest RFR rates are diabetic nephropathy and cystic kidney disease. Initial dialysis modality does not appear to influence RFR. Careful observation and history taking are needed to recognize the often nonspecific clinical and laboratory signs of RFR. When RFR is suspected in a chronic dialysis patient, a 24-hour urine urea and creatinine clearance should be measured. Based on the renal clearance, along with other clinical factors, the dialysis prescription may be gradually reduced until a complete discontinuation of dialysis. After RFR from maintenance dialysis, patients require close follow-up in an office setting for chronic kidney disease management.

Atheroembolic renal disease with rapid progression and fatal outcome

Atheroembolic renal disease is caused by foreign-body reaction to cholesterol crystals flushed from the atherosclerotic plaques into the small-vessel system of the kidneys. It is an underdiagnosed entity, mostly related to vascular procedures and/or anticoagulation, and prognosis is considered to be poor. Besides the benefit of aggressive medical prevention of further embolic events, use of steroid therapy has been associated with greater survival. Here we report a case of a patient with a multisystemic presentation of the disease days after performance of percutaneous coronary intervention and anticoagulation initiation due to an episode of myocardial infarction. Renal, cutaneous, ophthalmic, neurological, and possibly muscular and mesenteric involvement was diagnosed. Although medical treatment with corticosteroids and avoidance of further anticoagulation was applied, the patient rapidly progressed to end-stage renal disease requiring hemodialysis and died 6 months after diagnosis. This is a case of catastrophic progression of the disease resistant to therapeutic measures. Focus on diagnosis and more efficient preventive and therapeutic protocols are therefore needed.

Renovascular hypertension and ischemic nephropathy

Renovascular disease remains among the most prevalent and important causes of secondary hypertension and renal dysfunction. Many lesions reduce perfusion pressure including fibromuscular diseases and renal infarction, but most are caused by atherosclerotic disease. Epidemiologic studies establish a strong association between atherosclerotic renal-artery stenosis (ARAS) and cardiovascular risk. Hypertension develops in patients with renovascular disease from a complex set of pressor signals, including activation of the renin-angiotensin system (RAS), recruitment of oxidative stress pathways, and sympathoadrenergic activation. Although the kidney maintains function over a broad range of autoregulation, sustained reduction in renal perfusion leads to disturbed microvascular function, vascular rarefaction, and ultimately development of interstitial fibrosis. Advances in antihypertensive drug therapy and intensive risk factor management including smoking cessation and statin therapy can provide excellent blood pressure control for many individuals. Despite extensive observational experience with renal revascularization in patients with renovascular hypertension, recent prospective randomized trials fail to establish compelling benefits either with endovascular stents or with surgery when added to effective medical therapy. These trials are limited and exclude many patients most likely to benefit from revascularization. Meaningful recovery of kidney function after revascularization is limited once fibrosis is established. Recent experimental studies indicate that mechanisms allowing repair and regeneration of parenchymal kidney tissue may lead to improved outcomes in the future. Until additional staging tools become available, clinicians will be forced to individualize therapy carefully to optimize the potential benefits regarding both blood pressure and renal function for such patients.

Atheroembolic renal disease

Atheroembolic renal disease develops when atheromatous aortic plaques rupture, releasing cholesterol crystals into the small renal arteries. Embolisation often affects other organs, such as the skin, gastrointestinal system, and brain. Although the disease can develop spontaneously, it usually develops after vascular surgery, catheterisation, or anticoagulation. The systemic nature of atheroembolism makes diagnosis difficult. The classic triad of a precipitating event, acute or subacute renal failure, and skin lesions, are strongly suggestive of the disorder. Eosinophilia further supports the diagnosis, usually confirmed by biopsy of an affected organ or by the fundoscopic finding of cholesterol crystals in the retinal circulation. Renal and patient prognosis are poor. Treatment is mostly preventive, based on avoidance of further precipitating factors, and symptomatic, aimed to the optimum treatment of hypertension and cardiac and renal failure. Statins, which stabilise atherosclerotic plaques, should be offered to all patients. Steroids might have a role in acute or subacute progressive forms with systemic inflammation.

Segmental testicular infarction due to cholesterol embolism: not the first case, but the first report

Segmental infarction of the testis represents a rare entity in that there have been fewer than 40 cases documented in the literature. Like global infarction, segmental infarction of the testis can masquerade as a mass lesion or torsion of the testis. Reported herein is a very rare case of segmental testicular infarction due to atheroembolism in a 58-year-old man. The patient presented with severe left testicular pain and underwent left high orchiectomy on the clinical diagnosis of testicular torsion. The testis had a segmental hemorrhagic necrosis around which many cholesterol emboli were observed. This is the first report to describe cholesterol embolism-associated segmental testicular infarction.

The patient with acute kidney injury

During the past half decade there has been a paradigm shift in the view of acute kidney disease that has resulted in a change in nomenclature from the older term, "acute renal failure," to "acute kidney injury" (AKI). This article reviews the new criteria for diagnosis and staging of AKI and summarizes the current understanding of the many causes of AKI and the approach to diagnosis and management.

Intravascular iodinated contrast media and the anaesthetist

The use of intravascular iodinated contrast media (ICM) in radiological investigations is common. Increasingly, anaesthetists and intensivists are involved in the care of patients undergoing these investigations. Whilst the use of ICM is generally safe there are important adverse effects that need to be recognised and measures instigated to prevent or treat these effects. In patients at risk of developing adverse reactions it is important to consider alternative modes of imaging so that ICM can be avoided. Strategies for the prevention of ICM nephropathy should be considered in all patients receiving ICM. Currently intravascular volume expansion with 0.9% saline has the strongest evidence base. The use of isotonic sodium bicarbonate combined with N-acetylcysteine appears promising in providing further benefits. Although the use of N-acetylcysteine alone has not been shown to significantly reduce the incidence of ICM nephropathy it is cheap, has few adverse effects and it would seem reasonable to continue its use in conjunction with intravascular volume expansion. The routine use of corticosteroid and antihistamine premedication is not always effective in preventing general adverse reactions.

Cholesterol Embolization in Renal Allografts

Cholesterol embolization (CE) in renal allografts is a rare occurrence, the natural history and prognostic significance of which is poorly characterized. We studied the clinicopathologic features and outcome of the largest known series of CE in renal allografts and combined our cases with those in the literature. We identified renal allograft biopsies with CE from 1997 to September 2004 at University of Pittsburgh Medical Center (UPMC). All pathology material related to such biopsies were examined and correlated with clinical information to determine the most probable CE source. Among 5435 RAB, 19 from 12 cadaveric transplant recipients comprising 7 males and 5 females (median age=63 y) had CE. Donors consisted of 9 males and 2 females (median age=47 y). One donor's age and sex was unknown. The most probable CE source was recipient in 9 cases and donor in 3 cases. Five had acute renal failure without acute cellular rejection and 2 had CE-specific failed allografts. Of 19 RAB, the most frequent coexisting diagnosis was chronic allograft nephropathy (63%). The median follow-up time was 661 days. Combining UPMC and non-UPMC cases (n=37) revealed a statistically significant loss of grafts with donor-derived (P value=0.00459) and early CE (P value=0.00938). In renal allografts, CE most often correlated with recipient and donor atherosclerosis. It may present with acute renal failure, but usually not acute graft loss. Graft failure is significantly associated with donor-derived and early CE. Although its prognosis may be poor in the setting of primary nonfunction, prolonged graft survival may be seen.

Cholesterol Crystal Embolism Syndrome in Dialysis Patients: An Emerging Clinical Diagnosis?

BACKGROUND

Cholesterol crystal embolism syndrome (CCE) is an increasing end-stage renal disease cause. Few cases have been described on dialysis, despite the high prevalence of the predisposing factors.

METHODS

The diagnostic criteria of the present study were: skin lesions, myalgia, fatigue, fever and acute inflammatory serologic signs, in the presence of severe vasculopathy. The precipitating factors were: anticoagulation, endovascular intervention and ulcerated atherosclerotic plaque.

RESULTS

Between October 2003 and September 2005, CCE was diagnosed in 6 dialysis patients (of 200-210 on chronic treatment): 5 males, 1 female, median age 59.5 years (47-70) and end-stage renal disease follow-up 11.5 years (3-25). All had severe vasculopathy, 5 cardiopathy, and 4 were failed graft recipients. The treatment included: peritoneal dialysis, daily dialysis, 'conventional' hemodialysis (2 cases) and hemodiafiltration. The diagnosis was based on the clinical-laboratory picture in 1 patient. In the 5 others clues were present (dicumarol therapy, angioplasty, femoral artery thrombosis, CCE predialysis and ulcerated aortic plaque). The therapeutic approach consisted of corticosteroids (5 cases), statins (4 cases) and prostaglandin analogues (4 cases).

CONCLUSION

The differential diagnosis of CCE should also be considered in dialysis patients (necrotic lesions, limb pain and vasculitis-like signs).

Clinical characteristics and outcomes of Chinese patients with cholesterol crystal embolism after coronary intervention

BACKGROUND

Cholesterol crystal embolism (CCE) is a complication of atherosclerosis. Vascular surgery, vascular angiography, and anticoagulation have been identified as inciting factors.

HYPOTHESIS

This paper sought to analyze the clinical characteristics of patients with CCE after percutaneous coronary intervention.

METHODS

Six patients with atherosclerosis presenting with simultaneous occurrence of acute renal failure and peripheral ischemic changes were diagnosed with CCE and their clinical data were analyzed.

RESULTS

The average age of the patients was 72 years. Most had risk factors of atherosclerosis such as hypertension, diabetes, and smoking. The levels of serum creatinine increased progressively after coronary angiography. All patients had concomitant skin lesions, including blue toes. Cholesterol crystal emboli were found in arterioles by cutaneous biopsy in one patient. All patients received statins and two of these received dialysis therapy. Three patients died and three remained in chronic renal failure.

CONCLUSION

Since CCE is a severe complication of coronary intervention, special attention should be paid to this disease.