Atheroembolic renal disease

Predominantly multiple focal non-cystic renal lesions: an imaging approach

Multiple non-cystic renal lesions are occasionally discovered during imaging for various reasons and poses a diagnostic challenge to the practicing radiologist. These lesions may appear as a primary or dominant imaging finding or may be an additional abnormality in the setting of multiorgan involvement. Awareness of the imaging appearance of the various entities presenting as renal lesions integrated with associated extrarenal imaging findings along with clinical information is crucial for a proper diagnostic approach and patient work-up. This review summarizes the most relevant causes of infectious, inflammatory, vascular, and neoplastic disorders presenting as predominantly multiple focal non-cystic lesions.

Acute Kidney Injury in Patients with Acute Myocardial Infarction Undergoing Percutaneous Coronary Intervention: The Role of Vascular Access Site

Background: in patients undergoing percutaneous coronary interventions (PCI), radial access should be favoured over femoral access as it reduces the risk of vascular complications and bleeding. Furthermore, a preventive role of radial access in the occurrence of acute kidney injury (AKI), mainly mediated by the reduction of bleeding and cholesterol crystal embolization into renal circulation, has been investigated in several studies, yielding conflicting results. Methods: we designed a retrospective study to appraise the effect of the use of a vascular access site on the occurrence of AKI in a cohort of 633 patients with acute myocardial infarction treated by PCI at our centre from 2018 to 2020. Results: after propensity score adjustment, radial access was associated with a reduced, albeit statistically not significant, incidence of AKI (14.7% vs. 21.0%; p = 0.06) and major bleeding (12.5% vs. 18.7%; p = 0.04) as compared to femoral access. At multivariate analysis, femoral access was an independent predictor of AKI, together with in-hospital occurrence of BARC 3-5 bleeding, Killip class >1 at presentation, female gender, baseline eGFR <60 mL/min, and baseline haemoglobin <12 g/dL. Conclusions: although limited by the observational design, our study supports the hypothesis that radial access may exert a protective role on the occurrence of AKI in patients with acute myocardial infarction undergoing PCI.

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.

Pathophysiology and targeted treatment of cholesterol crystal embolism and the related thrombotic angiopathy

Cholesterol crystal (CC) embolism is a complication of advanced atherosclerotic plaques located in the major arteries. This pathological condition is primarily induced by interventional and surgical procedures or occurs spontaneously. CC can induce a wide range of tissue injuries including CC embolism syndrome, a spontaneous or intervention-induced complication of advanced atherosclerosis, while treatment of CC embolism has remained empiric. Vascular occlusions caused by CC embolism may exceed the ischemia tolerance of many tissues, particularly when small arteries are affected. The main approach to CC embolism is primary prophylaxis in patients at risk by stabilizing atherosclerotic plaques and avoiding unnecessary catheter interventions. During CC embolism, the use of platelet inhibitors to avoid abnormal activation and aggregation and anticoagulants may reduce the risk of vascular occlusions and tissue ischemia. This probably explains the relatively low prevalence of clinical manifestations of CC embolism, which are frequently found in autopsy studies. In this review, we summarized the current knowledge on the pathophysiology of CC embolism syndrome deriving from clinical observations and experimental mouse models. Furthermore, we described the risk factors of CC embolism in humans as well as the experimental studies based on empiric treatments. We also discuss potential therapeutic interventions based on recent experimental data and emerging drug options evolving from other research domains. Given the substantial unmet medical need to improve the outcomes of CC embolism, the identification of effective treatment strategies is urgently needed.

An Analysis of the Prevalence and Risk Factors of Contrast-Associated Acute Kidney Injury in Patients With Diabetic Foot Ulcer

The occurrence of contrast-associated acute kidney injury (CA-AKI) is influenced by both patient-related and contrast-related factors. More specifically, CA-AKI has been linked to renal dysfunction, diabetes mellitus (DM), and atherosclerotic cardiovascular diseases (ASCVD). We hypothesized that the prevalence of CA-AKI was high in patients with diabetic foot ulcers (DFU) because they frequently have several ASCVD risk factors and additional comorbid conditions (including ASCVD). We retrospectively examined the medical records of 208 type 2 diabetic patients who were hospitalized for DFU. These patients were divided into two groups: group 1 included 107 patients who underwent contrast-enhanced computed tomographic angiography (CTA); group 2 (control group) included 101 patients who did not receive contrast media. Following CTA, 13 (12.1%) patients developed CA-AKI in group 1, while 3 (3.0%) patients in group 2 had serum creatinine elevations consistent with AKI (P = 0.013). The following risk factors for CA-AKI were identified: longer history of DM, higher baseline serum creatinine, congestive heart failure, Wagner stage 4 and 5 DFUs, peripheral artery disease, older age, and lower hemoglobin values. CA-AKI is a common complication after CTA in patients with DFU. To reduce the risk of CA-AKI in these patients, associated risk factors and preventive measures should be considered.

Both hyperglycemia and hyperuricemia aggravate acute kidney injury during cholesterol embolism syndrome despite opposite effects on kidney infarct size

Kidney cholesterol crystal embolism (CCE) occurs in advanced atherosclerosis and induces a thrombotic (micro)angiopathy, a drop in the glomerular filtration rate (GFR), and an ischemic kidney infarction with necroinflammation. We speculated that common metabolic comorbidities such as diabetes or hyperuricemia would independently modulate each of these distinct pathophysiological processes. To test this, experimental CCE was induced by injecting cholesterol crystals into the left kidney artery of mice and thrombotic angiopathy, GFR drop, and infarct size were analyzed after 24 hours in the presence of hyperglycemia (about 500 mg/dL) or hyperuricemia (about 8 mg/dL) or their absence. In healthy mice, unilateral CCE caused diffuse thrombotic angiopathy in interlobar, arcuate and interlobular arteries, followed by a 50% or less drop in GFR compared to baseline and a variable degree of ischemic kidney necrosis. Hyperglycemia but not hyperuricemia aggravated thrombotic angiopathy although both caused a GFR decline, albeit via different mechanisms. Hyperglycemia aggravated GFR loss by increasing necroinflammation and infarct size, while the antioxidative effects of hyperuricemia reasonably attenuated necroinflammation and infarct size but induced a diffuse vasoconstriction in affected and unaffected kidney tissue. Thus, both hyperglycemia or hyperuricemia aggravate CCE-induced acute kidney failure despite having opposite effects on ischemic necroinflammation and infarction.

[Basic nephropathology for pathologists-part 2 : Non-inflammatory lesions]

The evaluation of kidney biopsies for specific renal diseases or kidney transplant biopsies is mainly restricted to specialized centers. Lesions in nonneoplastic renal tissue in partial nephrectomies or nephrectomies due to renal tumors, especially noninflammatory, ischemic, vascular changes or diabetic nephropathy can be of greater prognostic significance than the tumor itself in patients with a localized tumor and good tumor-associated survival. In this part of basic nephropathology for pathologists, the most common noninflammatory lesions of the vascular, glomerular and tubulo-interstitial compartment are discussed.

Spontaneous Cholesterol Embolism Leading to Small Bowel Obstruction and Perforation

A spontaneous occurrence of cholesterol embolization syndrome causing small bowel obstruction and perforation is a highly scarce event. In this article, we report a case of spontaneous cholesterol embolism resulting in small bowel obstruction and perforation in a 52-year-old male with multiple cardiovascular and medical comorbidities. In our patient, the source was an eccentric left lateral atherosclerotic plaque from the abdominal aorta that was identified using computed tomography. A distal occlusion in numerous small intestinal arteries due to cholesterol embolism was confirmed on biopsy after surgical resection. (Level of Difficulty: Intermediate.).

A comparison of thoracoabdominal aortic aneurysms open repair in patients with or without "shaggy aorta"

OBJECTIVE

In the field of thoracoabdominal aortic aneurysm (TAAA) open surgical repair (OSR), some preoperative characteristics are established risk factors for adverse outcomes, whereas others are supposed to be relevant, but their role still need to be defined; among them, the presence of "shaggy aorta" (SA), an extensive and irregular atheroma within the aorta. The aim of this study is to report the results of a single-center large cohort of patients treated with OSR for TAAA with SA, comparing the outcomes with patients affected by TAAA without SA, and analyzing the impact of the scores for SA on the outcomes.

METHODS

All consecutive patients receiving OSR for TAAA between 2012 and 2021 were retrospectively analyzed. Clinical data from patients with degenerative TAAA were included and analyzed for preoperative characteristics and postoperative outcomes; patients with ruptured TAAA, and patients with aortic dissection were excluded from the analysis. Patients with degenerative aortic aneurysm, thrombus measurement in non-aneurysmal aortic segments (≤40 mm), atheroma thickness ≥5 mm, and finger-like thrombus projection were included in the SA group, whereas the others were included in the non-shaggy aorta group (NSA group). The SA group and NSA group were compared using a propensity-matched comparison. Preoperative computed tomography scans of patients in the SA group were also stratified according to SA grading scores.

RESULTS

A total of 58 patients with SA were identified (male, n = 43 [74.1%], mean age 70.1 ± 7.8 years) among 497 patients with TAAA treated with open surgical repair. After propensity matching, there were 57 patients in the SA group and 57 in the NSA group with correction of all differences in baseline characteristics. Patients in the SA group presented significantly higher in-hospital mortality (SA group, 14.0% vs NSA group, 3.5%; P = .047), postoperative acute renal failure (Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease [RIFLE], 3-5) (SA group, 21.1% vs NSA group, 5.3%; P = .013), and postoperative embolization (SA group, 28.1% vs NSA group, 8.8%; P = .008). Spinal cord ischemia and stroke rate were not significantly influenced by the presence of SA. In the SA group, 16 patients (27.6%) with end-organ embolization were compared with 42 patients (72.4%) without a documented embolization considering the grade of aortic "shagginess" and no significant difference was identified (P = .546).

CONCLUSIONS

Despite a better knowledge of the SA disease, new classifications, and intraoperative adjuncts, TAAA patients with SA treated with OSR have worse postoperative outcomes if compared with patients without SA. The presence of SA is a risk factor itself, whereas the grade of "shagginess" seems not to impact on postoperative outcomes.

Intravenous Glu-plasminogen attenuates cholesterol crystal embolism-induced thrombotic angiopathy, acute kidney injury and kidney infarction

BACKGROUND

Cholesterol crystal (CC) embolism causes acute kidney injury (AKI) and ischaemic cortical necrosis associated with high mortality. We speculated that sustaining the fibrinolytic system with Glu-plasminogen (Glu-Plg) could be a safe way to attenuate AKI and prevent ischaemic infarction upon CC embolism.

METHODS

We induced CC embolism by injecting CC into the left kidney artery of C57BL/6J mice. The primary endpoint was glomerular filtration rate (GFR).

RESULTS

Starting as early as 2 h after CC embolism, thrombotic angiopathy progressed gradually in the interlobular, arcuate and interlobar arteries. This was associated with a decrease of GFR reaching a peak at 18 h, i.e. AKI, and progressive ischaemic kidney necrosis developing between 12-48 h after CC injection. Human plasma Glu-Plg extracts injected intravenously 4 h after CC embolism attenuated thrombotic angiopathy, GFR loss as well as ischaemic necrosis in a dose-dependent manner. No bleeding complications occurred after Glu-Plg injection. Injection of an intermediate dose (0.6 mg/kg) had only a transient protective effect on microvascular occlusions lasting for a few hours without a sustained protective effect on AKI at 18-48 h or cortical necrosis, while 1.5 mg/kg were fully protective. Importantly, no bleeding complications occurred.

CONCLUSIONS

These results provide the first experimental evidence that Glu-Plg could be an innovative therapeutic strategy to attenuate thrombotic angiopathy, AKI, kidney necrosis and potentially other clinical manifestations of CC embolism syndrome.

Asymptomatic retinal emboli and current practice guidelines: a review

Asymptomatic retinal emboli are found in 1-3% of patients on routine fundus examination. As the use of teleretinal imaging for diabetic patients and ocular photography continues to increase, the number of asymptomatic retinal emboli found will also increase. This article will discuss the different aetiologies of retinal emboli and will present an overview of the recommended referrals for further systemic testing and treatment. It is important to communicate well with the primary care physician when asymptomatic retinal emboli are detected to ensure the appropriate investigations are undertaken.

Cholesterol crystal embolism in multiple organs after transarterial chemoembolization for hepatocellular carcinoma: An autopsy case report

RATIONALE

Transcatheter arterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) rarely causes cholesterol crystal embolism (CCE). In our case, the histological findings suggested that the onset of CCE occurred at different time points in different organs.

PATIENT CONCERNS

A 72-year-old Japanese woman with HCC underwent TACE. After TACE, serum creatinine level and eosinophil count gradually increased. Three months later, she was admitted to our department with a fever and back pain.

DIAGNOSIS

Laboratory examinations showed sepsis with disseminated intravascular coagulation. She was treated with antimicrobial agents and anticoagulants, but died of multiple organ failure.

INTERVENTIONS

An autopsy was performed to examine the cause of multiple organ failure after 3 months of TACE.

OUTCOMES

A mixture of both chronic phase emboli with intimal thickening and fibrosis and acute phase emboli with inflammatory cell infiltration were observed in the small intestine. Moreover, multiple intravascular cholesterol fissures were observed in the kidney, stomach, duodenum, colon, pancreas, and spleen, which were the vascular dominant organs of the celiac artery and superior mesenteric artery. These histological findings suggested that cholesterol crystals were continuously disseminated after TACE.

LESSONS

TACE for HCC may cause progressive CCE and damage in multiple organs. When progressive renal dysfunction, eosinophilia, or multiple organ dysfunction is observed after TACE, the CCE should be suspected.

Neutrophil circadian rhythm is associated with different outcomes of acute kidney injury due to cholesterol crystal embolism

Cholesterol crystal (CC) embolism can cause acute tissue infarction and ischemic necrosis via triggering diffuse thrombotic angiopathy occluding arterioles and arteries. Neutrophils contribute to crystal-induced immunothrombosis as well as to ischemic necrosis-related necroinflammation. We speculated that CC embolism-induced acute kidney injury (AKI) would be circadian rhythm-dependent and associated with cyclic differences in neutrophil function. Injection of CC into the left kidney induced thrombotic angiopathy progressing starting as early as 3 h after CC injection followed by a progressive ischemic cortical necrosis and AKI at 24 h. In C57BL/6J mice, circulating CD11b+Ly6G+ neutrophils were higher during the day phase [Zeitgeber time (ZT) 0–12] compared to the dark phase (ZT12-24). In the time frame of thrombus formation at ZT13, more neutrophils were recruited into the injured kidney 24 h later compared to CC embolism at ZT5. This effect was associated with an increased circulating number of CXCR2+ neutrophils as well as an upregulated kidney adhesion molecule and chemokine expression. These findings were associated with a significant increase in kidney necrosis, and endothelial injury at ZT13. Thus, the time of day has an effect also on CC embolism-related AKI in association with the circadian rhythm of neutrophil recruitment.

[Basic nephropathology for pathologists-part 1 : Kidney biopsy-inflammation and immune complexes]

The assessment of kidney biopsies is mainly confined to specialized centres. However, sometimes a kidney biopsy is submitted to a general pathologist, and in addition peritumorous renal parenchyma in tumour nephrectomies can have concomitant non-neoplastic renal disease. Here we present a survey of inflammatory and immunologic changes in all renal compartments, which may in part indicate the need of prompt therapeutic intervention such as in vasculitis, glomerulonephritis and interstitial nephritis. It is important to take into account that renal involvement of vasculitis is mainly centred in glomeruli and only to a much lesser extent in arteries, and that the frequently observed interstitial inflammation very often is an epiphenomenon of another primary kidney disease and not an independent disease process. Typical renal patterns of injury are emphasised.

Outcomes of patients with Cholesterol crystal embolism treated by peritoneal dialysis: retrospective study from the RDPLF registry

Cholesterol crystal embolisms disease (CED) is a systemic disease characterized by tissue ischemia and microinflammation related to occlusion of arterioles by microemboli from ulcerated atheromatous plaques. The kidney is one of the most affected organs, often requiring dialysis. Our study examines the outcomes of a cohort of patients with CED treated with peritoneal dialysis (PD). As anticoagulants can favor emboli, peritoneal dialysis may theoretically have an advantage. From the database of the French Language Peritoneal Dialysis Registry (RDPLF), between January 1, 1995, and December 31, 2021, we selected patients treated with PD for >90 days and with an age >18 years. On the basis of the variables of patient autonomy, diabetes, BMI, modified Charlson index, age, sex, pre-PD treatment, causes of death, causes of transfer to hemodialysis, and peritonitis, three types of survival were estimated (patient, technical, and composite). After adjustment by propensity scores and taking into account competitive risks, 2 groups of patients were constituted on the basis of baseline nephropathy: emboli group vs. control group. Patient survival and strict technical survival are not associated with the type of nephropathy (CED versus others). Composite technical survival (uncensored for deaths and transfers to hemodialysis) was only associated with cholesterol emboli nephropathy in the multivariate analysis adjusted for diabetes, autonomy, and age of the patient at the start of the dialysis treatment (p=0.011; 95% CI [0.736 [0.581-0.931]]). Our study from the RDPLF database shows no difference in technical and patient survival in a cohort of patients with CED vs. a control group. It also confirms that PD may represent an adequate choice in this pathology.

[Epidemiology and Causes of Acute Renal Failure and Transition to Chronic Kidney Disease]

Acute kidney injury (AKI) refers to an acute functional deterioration of the kidneys, which leads to retention of urinary substances, dysregulation of the electrolyte and acid-base balance, and disturbance of fluids. Although didactically helpful, the oversimplified AKI classification of prerenal/renal/postrenal is currently considered obsolete. Indeed, the boundaries blur quite quickly, particularly between prerenal and renal causes. Based on the AKI pathophysiology, it can be etiologically divided into decreased renal perfusion, postrenal obstruction and kidney specific injury or unspecific injury. AKI is a common event in hospitalized patients and associates strongly with mortality and chronic kidney disease (CKD). Today it is accepted that AKI and CKD are rather an individually variable continuum, than 2 distinct entities. If AKI has not regressed after 7 days, it is referred to as acute kidney disease (AKD). Persisting AKD for > 90 days is classified as CKD. The transition from AKD to CKD is the result of an incomplete and maladaptive repair process. Although follow-up of post-AKI patients is essential, optimal concepts still need to be developed.

Cholesterol crystal embolism-related cerebral infarction: Magnetic resonance imaging and clinical characteristics

Background and aims

Cholesterol crystal embolism-related cerebral infarction (CCE-CI) is frequently misdiagnosed due to the lack of specific symptoms. To aid in differential diagnosis, this study comprehensively characterized the magnetic resonance imaging (MRI) and clinical manifestations of CCE-CI and compared these features to those of atherothrombotic cerebral infarction (ACI).

Methods

This single-center, retrospective, observational study was conducted at Kitasato University Hospital, Kanagawa, Japan. We identified 37 clinically or histopathologically confirmed CCE-CI cases and 110 ACI cases treated from January 2006 to May 2020. Groups were compared for mean age, sex ratio, clinical presentations, imaging manifestations, precipitating factors, comorbid conditions, medications, and smoking history.

Results

Of 37 eligible patients with CCE-CI, 10 (27.0%) received brain MRI, of which 8 (21.6%) exhibited high-intensity signals indicative of brain lesions on diffusion-weighted imaging (DWI). However, two patients with DWI lesions exhibited no detectable neurological abnormalities. Patients with CCE-CI frequently demonstrated bilateral DWI lesions involving the bilateral anterior and posterior circulation, a pattern absent in ACI (50% vs. 0%, p < 0.001). Compared to patients with ACI, CCE-CI patients also demonstrated significantly lower estimated glomerular filtration rate (p < 0.001) as well as more frequent eosinophilia (p = 0.006), atherosclerotic plaques ≥4-mm thick in the ascending aorta or proximal arch (p = 0.001), and aortic aneurysm (p < 0.001).

Conclusions

Patients with CCE-CI develop multiple DWI lesions across several vascular territories, even in the absence of neurological symptoms. Comorbid aortic aneurysm may increase CCE-CI risk. These findings could help in the differential diagnosis of CCE-CI.

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Diagnosis of CCE-CI is challenging due to nonspecific neurological symptoms.

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Brain DWI revealed multiple small ischemic lesions among patients with CCE-CI.

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CCE-CI was associated with atherosclerotic plaques in the ascending aorta and arch.

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CCE-CI was also associated with lower eGFR and higher blood eosinophil count.

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CCE-CI is associated with aortic aneurysm morbidity.

Burden of kidney failure from atheroembolic disease and association with survival in people receiving dialysis in Australia and New Zealand: a multi-centre registry study

Background

Cardiovascular disease is a leading cause of mortality in kidney failure (KF). Patients with KF from atheroembolic disease are at higher risk of cardiovascular disease than other causes of KF. This study aimed to determine survival on dialysis for patients with KF from atheroembolic disease compared with other causes of KF.

Methods

All adults (≥ 18 years) with KF initiating dialysis as the first kidney replacement therapy between 1 January 1990 and 31 December 2017 according to the Australia and New Zealand Dialysis and Transplant registry were included. Patients were grouped into either: KF from atheroembolic disease and all other causes of KF. Survival outcomes were assessed by the Kaplan-Meier method and Cox regression analysis adjusted for patient-related characteristics.

Results

Among 65,266 people on dialysis during the study period, 334 (0.5%) patients had KF from atheroembolic disease. A decreasing annual incidence of KF from atheroembolic disease was observed from 2008 onwards. Individuals with KF from atheroembolic disease demonstrated worse survival on dialysis compared to those with other causes of KF (HR 1.80, 95% confidence interval [CI] 1.61–2.03). The respective one- and five-year survival rates were 77 and 23% for KF from atheroembolic disease and 88 and 47% for other causes of KF. After adjustment for patient characteristics, KF from atheroembolic disease was not associated with increased patient mortality (adjusted HR 0.93 95% CI 0.82–1.05).

Conclusions

Survival outcomes on dialysis are worse for individuals with KF from atheroembolic disease compared to those with other causes of KF, probably due to patient demographics and higher comorbidity.

Novel Methods for Detecting Human Cholesterol Crystals from Sampled Blood

OBJECTIVE

Nonobstructive general angiography (NOGA) is a novel modality to detect and sample spontaneous ruptured aortic plaques (SRAPs). We aimed to establish novel methods to detect cholesterol crystals (CCs) in sampled SRAPs.

METHODS

Blood specimens containing SRAPs were obtained from patients using NOGA. Blood was instantly frozen on a glass slide and subsequently thawed for quantitative analysis and spread onto a filter paper that was rinsed using distilled water. Qualitative analysis was performed for the rinsed water using polarized light microscopy, and the filter paper was embedded in paraffin for histologic analysis.

RESULTS

The CCs were clearly observed after hemolysis using the instant freeze-thaw method. The filter paper rinse method indicated free CCs of varying shapes under polarized light microscopy without erythrocytes. On the filter paper, sampled SRAPs showed Lamé-like small particles. Histopathology revealed various atheromatous components.

CONCLUSION

A set of novel methods for detecting CCs from sampled blood was established.

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.

Contrast associated nephropathy after intravenous administration: what is the magnitude of the problem?

Intravenous contrast media (CM) is often used in clinical practice to enhance CT scan imaging. For many years, contrast-induced nephropathy (CIN) was thought to be a common occurrence and to result in dire consequences. When treating patients with abnormal renal function, it is not unusual that clinicians postpone, cancel, or replace contrast-enhanced imaging with other, perhaps less informative tests. New studies however have challenged this paradigm and the true risk attributable to intravenous CM for the occurrence of CIN has become debatable. In this article, we review the latest relevant medical literature and aim to provide an evidence-based answer to questions surrounding the risk, outcomes, and potential mitigation strategies of CIN after intravenous CM administration.

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

Supplemental Digital Content is available in the text.

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.

Efficacy of LDL apheresis for the treatment of cholesterol crystal embolism: A prospective, controlled study

This study was performed to evaluate the efficacy and safety of LDL apheresis (LDL-A) for the treatment of cholesterol crystal embolism (CCE) after cardiovascular procedures. We conducted a prospective multicenter study of 34 patients with CCE and 15 historical control patients. The present participants underwent six sessions of LDL-A for 4 weeks and underwent medical therapy with corticosteroids and statins. The mean creatinine concentration and estimated glomerular filtration rate at baseline were 3.82 ± 2.29 mg/dL and 17.8 ± 9.9 mL/min/1.73 m² , respectively. The prevalence of maintenance dialysis at 24 weeks was significantly lower in the present participants than in the historical controls (3.1% vs. 40.0%, respectively; p < 0.0001), but the mortality rate at 24 weeks was comparable (19% vs. 33%, respectively). Although 45 adverse events occurred in 23 participants, there were no unexpected adverse events. LDL-A for CCE reduces the prevalence of maintenance dialysis 24 weeks later and is well tolerated. This study was registered in the Japan Registry of Clinical Trials (jRCTs022180029) and clinicaltrials.gov (NCT01726868).

Harnessing the Physiological Functions of Cellular Prion Protein in the Kidneys: Applications for Treating Renal Diseases

A cellular prion protein (PrP^C) is a ubiquitous cell surface glycoprotein, and its physiological functions have been receiving increased attention. Endogenous PrP^C is present in various kidney tissues and undergoes glomerular filtration. In prion diseases, abnormal prion proteins are found to accumulate in renal tissues and filtered into urine. Urinary prion protein could serve as a diagnostic biomarker. PrP^C plays a role in cellular signaling pathways, reno-protective effects, and kidney iron uptake. PrP^C signaling affects mitochondrial function via the ERK pathway and is affected by the regulatory influence of microRNAs, small molecules, and signaling proteins. Targeting PrP^C in acute and chronic kidney disease could help improve iron homeostasis, ameliorate damage from ischemia/reperfusion injury, and enhance the efficacy of mesenchymal stem/stromal cell or extracellular vesicle-based therapeutic strategies. PrP^C may also be under the influence of BMP/Smad signaling and affect the progression of TGF-β-related renal fibrosis. PrP^C conveys TNF-α resistance in some renal cancers, and therefore, the coadministration of anti-PrP^C antibodies improves chemotherapy. PrP^C can be used to design antibody-drug conjugates, aptamer-drug conjugates, and customized tissue inhibitors of metalloproteinases to suppress cancer. With preclinical studies demonstrating promising results, further research on PrP^C in the kidney may lead to innovative PrP^C-based therapeutic strategies for renal disease.

A Rare Case of Coronavirus Disease 2019 Survival in an Elderly Patient With Atheroembolic Renal Disease

Atheroembolic renal disease (AERD) is a life-threatening illness. Coronavirus disease 2019 (COVID-19) has a high mortality rate in older patients with comorbidities. We report the case of severe-type COVID-19 in an 82-year-old female with AERD. She was treated with hydroxychloroquine-based therapy and overcame COVID-19. To our knowledge, this is the first report of a patient with AERD and COVID-19 pneumonia who overcame the infection and remains alive and well nine months following infection.

One concept does not fit all: the immune system in different forms of acute kidney injury

Renal and immune systems maintain body homoeostasis during physiological fluctuations and following tissue injury. The immune system plays a central role during acute kidney injury (AKI), adapting evolutional systems programmed for host defence and minimizing unnecessary collateral damage. Indeed, depending upon the disease context, the impact of the immune system upon the manifestations and consequences of AKI can be quite different. Here we provide an overview of the known and unknown involvement of the immune system within the wide range of different forms of AKI, to oppose oversimplification and to endorse deeper insights into the pathogenesis of the different diseases causing kidney injury. This approach may help to overcome some of the current hurdles in translational AKI research and the development of specific treatments for the different diseases, all presenting with an acute increase in serum creatinine or decline in urinary output. One concept does not fit all.

An Autopsy Case of Acute Pancreatitis Caused by Cholesterol Crystal Embolization

Cholesterol crystal embolization (CCE) shows a poor prognosis and it can cause ischemic organ damage due to a cholesterol embolism from atherosclerotic lesions in large blood vessels. Such an embolism mainly affects the kidneys and skin, although cases involving digestive organs have also been reported. We encountered an autopsy case of CCE with damage mainly to the digestive organs, including the pancreas. The patient had non-specific abdominal symptoms or image findings. Symptomatic therapy failed to save him. CCE can involve the digestive organs, and so must be differentiated from abdominal pathologies. Moreover, conventional treatments may be ineffective, and new treatments might thus be necessary.

Atheroembolic kidney disease: The under-recognized silent killer

While kidney biopsy demonstrating cholesterol crystal emboli is the method of definitive diagnosis; the triad of acute to subacute renal failure with skin findings in the setting of recent precipitating event should raise clinical suspicion for atheroembolic kidney disease.

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.

Cholesterol embolization syndrome and intra-abdominal bleeding immediately after initiation of hemodialysis: a case report with literature review

Background

Cholesterol embolization syndrome (CES) is a disease associating with the systemic cholesterol crystal embolism and end-organ dysfunction due to the atherosclerotic plaque rupture, which is dominantly triggered by the intravascular intervention. There is no consensus for which types of anticoagulants we should use during the hemodialysis in patients with CES and end-stage renal disease.

Case presentation

We had a 68-year-old man with CES due to intravascular intervention, who suffered the omental bleeding, instead of the embolism, immediately after the initiation of hemodialysis with heparinization. An emergent laparotomy found active bleeding from the omentum, which was surgically repaired. The histopathological analysis showed the embolization of cholesterol crystal clefts in the omentum artery and the injury of arterial wall structure accompanied by the infiltration of inflammatory cells. We preferred nafamostat mesylate during hemodialysis and he had no adverse events following the surgery.

Conclusions

It should be noticed that, in addition to the embolic events, bleeding events can develop in patients with CES, particularly following the initiation of hemodialysis with anticoagulation therapy.

Successful treatment of cholesterol crystal embolism with anti-proprotein convertase subtilisin/kexin type 9 (PCSK9) antibody: a case report

Background

We report a unique case of renal cholesterol crystal embolism (CCE) induced by carotid artery stenting that was successfully treated with evolocumab, a fully human monoclonal antibody against proprotein convertase subtilisin kexin type 9 (PCSK9).

Case presentation

A 77-year-old man with hypertension, hyperlipidemia, and chronic kidney disease was referred to our department for decreased estimated glomerular filtration rate (eGFR)—from 32.0 to 13.9 mL/min/1.73 m²—5 weeks after carotid artery stenting. Further examination revealed livedo reticularis in the bilateral toes and eosinophilia (723/μL). Skin biopsy from livedo reticularis tissue in the bilateral toes showed cholesterol clefts in the small arteries. The patient was therefore diagnosed with CCE. After 25 weeks’ administration of evolocumab at a dose of 140 mg subcutaneously administered every 2 weeks, his eGFR had improved from 10.7 to 18.1 mL/min/1.73 m².

Conclusion

Evolocumab may have a beneficial effect on renal involvement in patients with CCE.

Effect of Atheromatous Aorta on Thromboembolic Complications after Endovascular Aortic Aneurysm

Objective: The purpose of this study was to evaluate the effect of atheromatous aorta on thromboembolic complications after endovascular aortic aneurysm repair (EVAR) and to assess the risk factors for these complications. Materials and Methods: This retrospective study included patients who underwent EVAR for an abdominal aortic aneurysm at the Shizuoka Red Cross Hospital from 2007 to 2018. We defined atheromatous aorta as a thoracic shaggy aorta or abdominal aorta with neck thrombus. The main outcome was renal dysfunction and peripheral embolization (thromboembolic complications). We compared the incidence of thromboembolic complications between patients with normal aorta and atheromatous aorta. Moreover, we assessed the risk factors associated with thromboembolic complications in patients with atheromatous aorta. Results: Patients with atheromatous aorta had significantly more thromboembolic complications, such as renal dysfunction (24.5% vs. 3.9%; P<0.001) and peripheral embolization (12.3% vs. 0.0%; P<0.001) than those with normal aorta, respectively. We identified no risk factors associated with thromboembolic complications in patients with atheromatous aorta. Conclusion: Atheromatous aorta increases the risk of thromboembolic complications after EVAR. However, there is no established therapy for these thromboembolic complications. Further studies are necessary to determine the appropriate therapy, including appropriate preoperative medication, to prevent these complications.

Proportion and risk factors of cholesterol crystal embolization after cardiovascular procedures: a retrospective national database study

Cholesterol crystal embolization (CCE) is a rare, mainly iatrogenic condition. The proportion of CCE after cardiovascular procedures has not been fully elucidated. The purpose of this study was to determine the proportion of CCE diagnosed after cardiovascular procedures and to identify risk factors for CCE occurrence. Data on patients aged older than 40 years who underwent cardiovascular procedures between July 2010 and March 2017 were extracted from the Japanese Diagnosis Procedure Combination database. Inpatients diagnosed with CCE within 1 year after procedures in the same hospital were identified. Logistic regression analysis was performed to identify factors associated with the occurrence of CCE. There were 962 patients with CCE in 2,190,300 patients who underwent cardiovascular procedures. The overall proportion of CCE after cardiovascular procedures was 4.4 per 10,000 patients (95% confidence interval 4.1-4.7). The overall in-hospital mortality among patients with CCE was 11% (107/962). Older age, male sex, smoking, heart failure, peripheral vascular disease, cerebrovascular disease, renal insufficiency, diabetes mellitus, hypertension, and aortic aneurism and dissection were significantly associated with the higher occurrence of CCE. Compared with cardioangiography, several procedures were significantly associated with higher occurrence of CCE, including intra-aortic balloon pumping, percutaneous transluminal angioplasty of the renal artery, and transcatheter aortic valve implantation or balloon aortic valvuloplasty. CCE is rare but remains a severe complication of cardiovascular procedures. Atherosclerotic risk factors and certain cardiovascular procedures were associated with CCE.

Association between eosinophilia and renal prognosis in patients with pathologically proven cholesterol crystal embolism

Background

Approximately, 20–70% of patients with cholesterol crystal embolism (CCE) have eosinophilia. However, it remains unknown how eosinophilia influences renal prognosis in patients with CCE. In this study, we investigated the association between eosinophil count (Eo) and renal prognosis in CCE patients on steroid therapy.

Methods

The present study is a single-centered retrospective cohort study in patients with renal dysfunction and CCE from April 2007 to May 2018. This study included the patients who were treated with neither maintenance dialysis nor steroid before CCE diagnosis, and followed-up for kidney function until November 2019. We assessed whether eosinophilia at the time of CCE diagnosis was related to renal death after treating with steroid therapy.

Results

Thirty patients with pathologically diagnosed CCE were enrolled and followed-up for 11.0 (5.2–43.4) months. There were significant differences in the white blood cell count (p = 0.01), hemoglobin (p = 0.009), serum creatinine levels (p = 0.008), phosphate (p = 0.049), and Eo (p = 0.008) between the renal survival and renal death groups. Using the receiver operating characteristic curve analysis with Youden index, Eo of 810/µL showed 100% sensitivity and 69.6% specificity for detecting renal death (area under the curve: 0.839). Comparing the outcomes in patients having Eo ≥ and < 810/µL using the log-rank test, there is a significantly higher renal death rate in CCE patients with Eo ≥ 810/µL (p = 0.0016).

Conclusion

Higher eosinophilia was a prognostic risk factor for renal death in the patients with CCE.

Incidence, risk factors and prognostic impact of acute kidney injury after coronary angiography and intervention in kidney transplant recipients: a single-center retrospective analysis

Introduction

Kidney transplant recipients (KTR) represent a high-risk population for cardiovascular disease. Coronary artery disease (CAD) is the most common cause of morbidity and mortality in this population. In KTR, coronary angiography and intervention (CI) can be associated with the risk of acute kidney injury (AKI).

Aim

Data about the incidence and impact of AKI after CI in this population are rare. The aim of the present study is to describe the incidence and risk factors of AKI, periprocedural bleeding and the prognostic impact on 1-year mortality in KTR undergoing CI.

Material and methods

This retrospective single-center study includes all KTR undergoing CI at University Hospital Frankfurt between 2005 and 2015.

Results

A total of 135 CIs in KTR were analyzed. AKI occurred in 31 of 135 CIs (23%, AKI group). Patients of the AKI group were older; other baseline characteristics did not show significant differences. The amount of contrast dye used was higher in the AKI group (p = NS). Periprocedural bleeding defined by BARC criteria occurred more often in the AKI group (23% vs. 5%, p < 0.01) and persisted as a risk factor of AKI in multivariate analysis (odds ratio = 6.43, 95% CI: 1.78–23.20, p = 0.01). In-hospital mortality was 3% in the AKI group; no patient of the non-AKI group died during hospitalization (p = 0.2). One-year-survival was significantly higher in the non-AKI group (94% vs. 81%, p = 0.02).

Conclusions

AKI is an important prognostic determinant in KTR undergoing coronary angiography and percutaneous coronary intervention (PCI). Periprocedural bleeding events were associated with AKI. Well-known risk factors for AKI such as contrast agent and diabetes were of minor impact.

[Cholesterol crystal embolism mimicking a DRESS]

INTRODUCTION

Clinical presentation of cholesterol crystal embolism (CCE) can be dermatologic when cholesterol crystals become lodged in small cutaneous arteries resulting in ischemia. We report a case of CCE with erythroderma misleading to a diagnostic of drug reaction with eosinophilia and systemic symptoms (DRESS).

CASE REPORT

A 66 year-old woman presented with erythroderma few months after initiation of allopurinol. Acute renal failure was present with elevation in plasma creatinine concentration (523μmol/L) and hypereosinophilia (HE) (5666/mm³). Finally, the REGISCAR score helped to rule out DRESS diagnostic. Past blood-count tests were analyzed revealing chronic HE present before allopurinol initiation. Renal biopsy identified CCE.

CONCLUSION

This case is the first to report a DRESS like presentation of CCE. Clinical findings are secondary to HE and not to occlusion of cutaneous arteries.

Gastric remnant necrosis secondary to cholesterol crystal embolization after distal gastrectomy in a gastric cancer patient: a case report

Background

Distal gastrectomy with lymph node dissection, a standard operative technique for gastric cancer treatment, is safely performed because the stomach has a rich vascular supply. Gastric remnant necrosis caused by cholesterol crystal embolization following distal gastrectomy has not been described previously. We report a case of gastric remnant necrosis in a patient with cholesterol crystal embolization.

Case presentation

A 70-year-old man with a history of cholesterol crystal embolization presented to our surgery department with complaints of anorexia and dysphasia. He was diagnosed with gastric cancer invading the pyloric antrum and underwent distal gastrectomy with Billroth 2 reconstruction. On postoperative day 11, he developed abdominal pain without fever. Emergency laparotomy revealed that most parts of the remnant stomach were necrosed. Total gastrectomy with Roux-en-Y reconstruction and abscess drainage were performed. After surgery, anastomotic leakage occurred and was treated conservatively. However, the superior pancreaticoduodenal artery aneurysm suddenly ruptured and he expired.

Conclusions

Gastric remnant necrosis after distal gastrectomy can be a gastrointestinal presentation of cholesterol crystal embolization. Perioperative/intraoperative risk assessments such as preventive total gastrectomy or intraoperative assessment with indocyanine green fluorescence angiography may be desirable to avoid this complication.

Iloprost in Acute Post-kidney Transplant Atheroembolism: A Case Report of Two Successful Treatments

Cholesterol embolization (CE) is a rare and alarming post-transplant complication, responsible for primary non-function (PNF) or delayed graft function (DGF). Its incidence is expected to rise due to increasingly old donors and recipients and the extended criteria for donation. Therapy with statins and steroids has not been shown to be effective, while agonism of prostaglandin I₂ has been reported to be useful in systemic CE. We report two cases of acute post-transplant CE in which intravenous iloprost (0.05 mg/kg/day) was added to standard statin and steroid therapy. In the first instance, CE was due to embolization from the kidney artery resulting in embolization of the small vessels; after a long DGF and 15 days of iloprost therapy, renal function recovered. The second instance is a case of embolization from the iliac artery of the recipient, where CE manifested as a partial renal infarction. After 5 days of iloprost administration, creatinine levels improved. Iloprost acts on vasodilation and on different inflammatory pathways, improving the anti-inflammatory profile. Post-transplant CE is difficult to diagnose and, if not treated, can lead to loss of function. Iloprost added to standard therapy could be beneficial in accelerating renal function recovery immediately after transplant.

Crystal Clots as Therapeutic Target in Cholesterol Crystal Embolism

RATIONALE

Cholesterol crystal embolism can be a life-threatening complication of advanced atherosclerosis. Pathophysiology and molecular targets for treatment are largely unknown.

OBJECTIVE

We aimed to develop a new animal model of cholesterol crystal embolism to dissect the molecular mechanisms of cholesterol crystal (CC)-driven arterial occlusion, tissue infarction, and organ failure.

METHODS AND RESULTS

C57BL/6J mice were injected with CC into the left kidney artery. Primary end point was glomerular filtration rate (GFR). CC caused crystal clots occluding intrarenal arteries and a dose-dependent drop in GFR, followed by GFR recovery within 4 weeks, that is, acute kidney disease. In contrast, the extent of kidney infarction was more variable. Blocking necroptosis using mixed lineage kinase domain-like deficient mice or necrostatin-1s treatment protected from kidney infarction but not from GFR loss because arterial obstructions persisted, identifying crystal clots as a primary target to prevent organ failure. CC involved platelets, neutrophils, fibrin, and extracellular DNA. Neutrophil depletion or inhibition of the release of neutrophil extracellular traps had little effects, but platelet P2Y12 receptor antagonism with clopidogrel, fibrinolysis with urokinase, or DNA digestion with recombinant DNase I all prevented arterial occlusions, GFR loss, and kidney infarction. The window-of-opportunity was <3 hours after CC injection. However, combining Nec-1s (necrostatin-1s) prophylaxis given 1 hour before and DNase I 3 hours after CC injection completely prevented kidney failure and infarcts. In vitro, CC did not directly induce plasmatic coagulation but induced neutrophil extracellular trap formation and DNA release mainly from kidney endothelial cells, neutrophils, and few from platelets. CC induced ATP release from aggregating platelets, which increased fibrin formation in a DNase-dependent manner.

CONCLUSIONS

CC embolism causes arterial obstructions and organ failure via the formation of crystal clots with fibrin, platelets, and extracellular DNA as critical components. Therefore, our model enables to unravel the pathogenesis of the CC embolism syndrome as a basis for both prophylaxis and targeted therapy.

[Update on cholesterol crystal embolism]

Cholesterol crystal embolism is a systemic pathology associated with diffuse atherosclerosis. Pathophysiology corresponds to tissue necro-inflammation secondary to arteriolar occlusion associated with microembolism from atherosclerotic plaques of large diameter arteries. The clinical presentation is heterogeneous and polymorphic. Multiple organs may be the targets, but preferential damage is skin, kidneys and digestive system. It is a serious pathology, underdiagnosed, with a poor prognosis. The risk factors for developing the disease remain the same risk factors as atheroma. The factors favouring migration of microembolism remain mainly vascular interventional procedures; easy to diagnose, they oppose spontaneous embolic migrations or secondary to the introduction of antithrombotic treatment, whose diagnosis is more difficult and the prognosis more severe. The diagnosis of the disease remains mostly a diagnosis of elimination and often refers to a bundle of clinical, biological, morphological and histologic arguments. The treatment is poorly codified and the subject of few publications. It will favour both symptomatic treatment (and mainly that of pain) and complications (high blood pressure, renal insufficiency). The aetiological support remains less consensual. The treatment of atherosclerotic plaques consists, of course, in the correction of classical cardiovascular risk factors, the introduction of a statin. It will be discussed in the implementation of surgery or angioplasty to exclude potentially responsible atherosclerotic lesions. Eviction of antithrombotic therapy should be considered in terms of the benefit-risk balance, but often in favour of maintaining it. Finally, other treatments may be proposed in a case-by-case basis, such as oral or intravenous corticosteroid therapy, colchicine or LDL aphaeresis.

Fenestrated-branched endovascular aortic repair in patients with chronic kidney disease

OBJECTIVE

Renal function impairment is a common complication after open repair of complex abdominal aortic aneurysms and thoracoabdominal aortic aneurysms (TAAAs). The purpose of this study was to assess renal perioperative outcomes and renal function deterioration after fenestrated-branched endovascular aneurysm repair (F/BEVAR) in patients with chronic kidney disease (CKD).

METHODS

The study included 186 patients who underwent F/BEVAR between 2013 and 2018 for suprarenal, juxtarenal, and type I to type IV TAAAs. Glomerular filtration rate (GFR) was calculated using the Modification of Diet in Renal Disease (MDRD) study equation. Postoperative acute kidney injury (AKI) and CKD were defined using RIFLE criteria (Risk, Injury, Failure, Loss, and End-stage renal disease) and CKD staging system (stage ≥3, GFR <60 mL/min/1.73 m²), respectively. For those without baseline CKD, renal decline was defined as a drop in GFR <60 mL/min/1.73 m² (ie, progression to CKD stage 3 or higher). For patients with baseline renal dysfunction, GFR decline ≥20% or progression in CKD stage (ie, from stage 3 to stage 4) was considered renal decline.

RESULTS

CKD was present in 83 patients (44.6%). Postoperative AKI was diagnosed in 27 patients (14.5%); 13 (48.1%) had history of CKD and 14 (51.9%) had adequate renal function preoperatively (P = .8). None of these patients required permanent renal replacement therapy. Intraoperative technical success was 100%. Overall 30-day mortality was 1.1%. There was no difference in 30-day mortality in patients with (1.2%) and without (1.0%) CKD (P = .5). During a median follow-up time of 12 months (interquartile range, 6-23 months), renal decline was observed in 21 patients (25.3%) with previous CKD and in 11 patients (10.6%) without CKD (P = .01). Among patients with previous CKD, 18 patients (9%) progressed from stage 3 CKD to stage 4. In patients with progression in CKD stage, two (5%) had renal stent stenosis requiring restenting. Among patients with renal decline, 13 had juxtarenal aneurysms (21.3%), 27 had suprarenal aneurysms (44.3%), and 21 had TAAAs (34.3%; P = .4). Subset analysis of patients who developed AKI in the immediate postoperative period found that patients with a history of CKD were less likely to experience freedom from renal decline.

CONCLUSIONS

F/BEVAR is an effective and safe procedure for patients with complex abdominal aortic aneurysms and TAAAs, even among patients with CKD. The frequency of AKI was not affected by pre-existing CKD. Midterm outcomes demonstrated that progression of CKD was more frequent among patients with pre-existing CKD, but permanent renal replacement therapy was not required. Anatomic extent of aneurysms did not affect CKD progression. CKD patients are susceptible to renal decline over time if they experience AKI in the postoperative period. Therefore, preventing AKI in the postoperative period should be regarded as a priority. Long-term effects of CKD after F/BEVAR remain to be elucidated.