Long-Term Renal Function after Endovascular Aneurysm Repair

Differences in mortality and risk factors, two years after endovascular repair of ruptured abdominal aortic aneurysms - Reassessment analysis

OBJECTIVE

The prevalence of abdominal aortic aneurysms (AAA) increases with age. Elective intervention for AAA is critical to prevent rupture associated with very high mortality among older males.

METHODS

The aim of this study was to address the impact of post-contrast acute kidney-PC-AKI injury among patients treated with endovascular repair of ruptured AAA-EVAR on outcomes such as new onset chronic kidney disease-CKD and mortality among patients within a two-year trial.

RESULTS

The same study group (of n = 192 patients) underwent reassessment, two years after EVAR treatment. The overall mortality rate was 16.67%, and it was higher in the AKI group - 38.89%. CKD patients had a mortality rate of 23.88% (n = 16). Among patients with an aneurysm diameter >67 mm mortality rate reached 20% (n = 6), while in the previously reported diabetes mellitus group 37.93% (n = 11). New onset of CKD was diagnosed in 23% of cases. Preexisting CKD patients with PC- AKI contributed to a 33.33% mortality rate (n = 8).

CONCLUSION

This study concludes that PC-AKI impacts outcomes and survival in endovascularly treated AAAs. Type 2 diabetes and preexisting chronic kidney disease are associated with higher mortality within a 2-year follow-up, however gender factor was not significant. A larger aneurysm diameter is related with a higher prevalence of PC-AKI. These factors should be taken into account during screening, qualifying patients for the treatment and treating patients with AAA. It may help to identify high-risk individuals and tailor preventive measurements and treatment options accordingly, improving treatment results and reducing mortality.

Comparative study of acute kidney injury in pararenal aortic aneurysm: open surgical versus endovascular repair

Background

Pararenal abdominal aortic aneurysms (PR-AAA), constituting around 15%-20% of AAA patients, are defined as having no neck between the aneurysm and the renal arteries. Due to an insufficient sealing zone, open surgical repair (OSR) is the gold standard, while EVAR is reserved for those unfit for surgery. Renal outcomes disturb long-term survival, and they have massive socioeconomic and quality of life implications, especially if patients require dialysis.

Methods

This study aims to elucidate any difference between EVAR and OSR of PR-AAA, excluding suprarenal aneurysms, with specific emphasis on renal dysfunction over the short and long term. An existing database of PR-AAA between 2002 and 2023 was used to glean information regarding the therapeutic option used. Renal events were defined by the RIFLE criteria. Out of 1,563 aortic interventions, we identified 179 PR-AAA, of which 99 high-risk patients had an aortic neck of less than 10 mm with complete follow-up. We excluded patients with fenestrated EVAR (FEVAR), branched EVAR (BEVAR), or chimney EVAR (Ch-EVAR) and any patients requiring visceral artery reimplantation.

Results

In total, 63 patients underwent EVAR, and 36 required OSR. 17.46% of patients who underwent EVAR experienced acute kidney injury (AKI) compared with 36.11% of the OSR group (P = 0.037). The mean post-op creatinine for OSR was 109.88 µmol/L, and for EVAR was 127.06 µmol/L (P = 0.192). The mean difference between long-term (9-12 years) creatinine values in OSR was 14.29 µmol/L (P = 0.191), and the mean difference for EVAR was 25.05 µmol/L (P = 0.024). Furthermore, 27.8% of OSR patients who underwent Left Renal Vein Division and Ligation (LRVDL) experienced an AKI, while 50% who did not undergo LRVDL experienced an AKI (P = 0.382). Thirty-day morbidity in the EVAR group (20.97%) was significantly lower than in the OSR group (42.62%) (P = 0.022). Moreover, 3.17% in EVAR group and 7.14% in OSR group had aneurysm-related mortality (P = 0.584).

Conclusion

The rate of renal events for OSR is higher, while the rate of endovascular renal events was lower. Our study shows that PR-AAA undergoing OSR may benefit from endovascular repair.

Long-Term Effects of Acute Kidney Injury Following Endovascular Femoropopliteal Intervention: Insights From a Multicenter Trial

PURPOSE

To examine the association between acute kidney injury (AKI) severity and duration with cardiovascular mortality, following endovascular treatment of femoropopliteal disease, and whether it is AKI in itself that confers an increased risk of cardiovascular mortality.

METHODS

A retrospective analysis of prospectively collected data obtained between 2014 and 2019 from 3 vascular centers. Renal function was followed up for a minimum of 90 days. Electronic records were queried to establish a cause of death, where applicable. Patients were excluded if unable to provide written informed consent or if presenting with acute limb ischemia. Primary outcomes were the hazard ratios for cardiovascular death (AKI patients vs no AKI; no AKI vs stage 1 AKI vs stage 3 AKI; and no AKI vs transient AKI vs established AKI). Propensity score-matched analysis was used to establish whether developing AKI, in patients with similar demographics and procedural characteristics, is associated with a higher risk of cardiovascular death.

RESULTS

Overall 239 patients developed AKI, and this was associated with an increased risk of cardiovascular mortality (hazard risk [HR]: 4.3, 95% confidence intervals [CIs]: 2.1-6.8, pairwise comparison p value=0.006]. This was dependent on the severity of the AKI stage (HR 5.4, 95% CI: 2.4-7.3, pairwise comparison p value=0.01) and duration (HR 4.2, 95% CI: 2.3-6.2, pairwise comparison p value=0.04). The propensity score-matched analysis showed that even when patients are matched for comorbidity and procedural characteristics, AKI confers an increased risk of mortality (p=0.04).

CONCLUSIONS

Acute kidney injury is common after femoropopliteal endovascular therapy. It confers an increased risk of long-term cardiovascular mortality, which is still present when renal decline is transient, and highest for patients with established decline in renal function.

CLINICAL IMPACT

This is the first study in the setting of peripheral arterial disease to show that acute kidney injury has an adverse effect on cardiovascular mortality, in the long-term, that is dependent on its severity, and present even when the AKI is transient. We have also shown that this difference in cardiovascular mortality becomes more pronounced from the medium-term, and thus closer follow-up of these patients is required.

Spectral computed tomography angiography using a gadolinium-based contrast agent for imaging of pathologies of the aorta

OBJECTIVES

Especially patients with aortic aneurysms and multiple computed tomography angiographies (CTA) might show medical conditions which oppose the use of iodine-based contrast agents. CTA using monoenergetic reconstructions from dual layer CT and gadolinium (Gd-)based contrast agents might be a feasible alternative in these patients. Therefore, the purpose of this study was to evaluate the feasibility of clinical spectral CTA with a Gd-based contrast agent in patients with aortic aneurysms.

METHODS

Twenty-one consecutive scans in 15 patients with and without endovascular aneurysm repair showing contraindications for iodine-based contrast agents were examined using clinical routine doses (0.2 mmol/kg) of Gd-based contrast agent with spectral CT. Monoenergetic reconstructions of the spectral data set were computed.

RESULTS

There was a significant increase in the intravascular attenuation of the aorta between pre- and post-contrast images for the MonoE40 images in the thoracic and the abdominal aorta (p < 0.001 for both). Additionally, the ratio between pre- and post-contrast images was significantly higher in the MonoE40 images as compared to the conventional images with a factor of 6.5 ± 4.5 vs. 2.4 ± 0.5 in the thoracic aorta (p = 0.003) and 4.1 ± 1.8 vs. 1.9 ± 0.5 in the abdominal aorta (p < 0.001).

CONCLUSIONS

To conclude, our study showed that Gd-CTA is a valid and reliable alternative for diagnostic imaging of the aorta for clinical applications. Monoenergetic reconstructions of computed tomography angiographies using gadolinium based contrast agents may be a useful alternative in patients with aortic aneurysms and contraindications for iodine based contrast agents.

Risk factors for readmission after open abdominal aortic aneurysms repair and its outcome in chronic kidney disease patients

OBJECTIVE

Readmission after vascular procedures is a burden to hospitals and the Medicare system. Therefore, identifying risk factors leading to readmission is vital. We examined the frequency of and risk factors for 30-day readmission after open aneurysm repair (OAR) and explored post-operative outcomes with special attention for those with preexisting chronic kidney disease (CKD).

METHODS

Patients who underwent OAR were identified in the National Readmission Database (2016-2018). Demographic information and comorbidities were collected. Patients readmitted within 30 days after their index hospitalization were identified and compared to patients without readmission records.

RESULTS

A total of 5090 patients underwent OAR during the study timeframe with 488 patients (9.6%) were readmitted within 30 days. Females were more readmitted than males (F = 11.1% vs M = 9.0%, P < 0.001). Readmitted patients had more comorbidities (median ECI 12, P < 0.05), were on Medicare (73.7%, P < 0.001), had higher surgery admission cost ($146,844, P < 0.001), longer length of stay (8 days, P < 0.001), and were discharged to a lower level care facility (62.7%, P < 0.001). Comorbidities that predisposed patients for readmission include: peripheral arterial disease (OR 2.15, P < 0.01), asthma (OR 1.87, P < 0.01), chronic heart failure (OR 1.74, P < 0.05). On readmission visit, acute renal failure (23.8%) was the most common diagnosis, while intestinal surgery (13.7%) was the most common procedure. Patients with CKD (n = 968, 18.9% of total population) had double the mortality rate compared to non-CKD patients on surgery admission (10.4%, P < 0.001) and readmission (10.1%, P < 0.001).

CONCLUSION

Certain factors were noted to increase readmission rate, special attention need to be paid when dealing with such group of patients requiring OAR. Vascular surgeons should meticulously weigh benefits and risks when considering OAR in patients with CKD who are not a candidate for endovascular repair, and optimize their kidney function before considering such approach.

Investigation of Renal Decline and New Onset Dialysis Following Endovascular Aneurysm Repair in the Vascular Quality Initiative

INTRODUCTION

The purpose of this study is to identify variables significantly associated with renal function decline after elective endovascular infra-renal abdominal aortic aneurysm repair and to identify the rate and risks of subsequent progression to dialysis. Specifically, we investigate the long-term impact of supra-renal fixation, female gender, and physiologically stressful perioperative events on renal function following endovascular aneurysm repair (EVAR).

METHODS

Review of all EVAR cases in the Vascular Quality Initiative between 2003 and 2021 was conducted to investigate variable associations with three primary outcomes: postoperative acute renal insufficiency (ARI); greater than 30% decline in glomerular filtration rate (GFR) in patients beyond 1 year of follow up; and new onset dialysis requirement at any point in follow up. Binary logistic regression analysis was performed for the events of acute renal insufficiency and new onset dialysis requirement. Cox proportional hazard regression was performed regarding long term GFR decline.

RESULTS

Postoperative ARI occurred in 3.4% (1692/49 772) of patients. Significant (P < .05) association with postoperative ARI was noted for: age (OR 1.014/year, 95% CI 1.008-1.021); female gender (OR 1.44, 95% CI 1.27-1.67); hypertension (OR 1.22, 95% CI 1.04-1.44); chronic obstructive pulmonary disease (OR 1.34, 95% CI 1.20-1.50); anemia (OR 4.24, 95% CI 3.71-4.84); reoperation at index admission (OR 7.86, 95% CI 6.47-9.54); baseline renal insufficiency (OR 2.29, 95% CI 2.03-2.56); larger aneurysm diameter; increased blood loss; and higher volumes of intra-operative crystalloid. Risk factors (P < .05) correlating with a decline of 30% in GFR at any time beyond 1 year were: female gender (HR 1.43, 95% CI 1.24-1.65); body mass index (BMI) less than 20 (HR 1.34, 95% CI 1.03-1.74); hypertension (HR 1.38, 95% CI 1.15-1.64); diabetes (HR 1.34, 95% CI 1.17-1.53); COPD (HR 1.21, 95% CI 1.07-1.37); anemia (HR 1.92, 95% CI 1.52-2.42); baseline renal insufficiency (HR 1.31, 95% CI 1.15-1.49); absence of discharge ace-inhibitor (HR 1.27, 95% CI 1.13-1.42); long term re-intervention (HR 2.43, 95% CI 1.84-3.21) and larger AAA diameter. Patients who experienced long term GRF decline had a significantly higher long-term morality. New onset dialysis following EVAR occurred in .47% (234/49 772) of those meeting inclusion criteria. Higher rate (P < .05) of new onset dialysis was associated with age (OR 1.03/year, 95% CI 1.02-1.05); diabetes (OR 1.376, 95% CI 1.005-1.885); baseline renal insufficiency (OR 6.32, 95% CI4.59-8.72); Reoperation at index admission (OR 2.41, 95% CI 1.03-5.67); postoperative ARI (OR 23.29, 95% CI 16.99-31.91); absence of beta blocker (OR 1.67, 95% CI 1.12-2.49); long term graft encroachment on renal arteries (OR 4.91, 95% CI 1.49-16.14).

CONCLUSIONS

New onset dialysis following EVAR is a rare event. Perioperative variables influencing renal function following EVAR include blood loss, arterial injury, and reoperation. Supra-renal fixation is not associated with postoperative acute renal insufficiency or new onset dialysis in long term follow up. Renal protective measures are recommended for patients with baseline renal insufficiency undergoing EVAR as acute renal insufficiency following EVAR portends a 20-fold increased risk of new onset dialysis in long term follow up.

CT Angiography of the Aorta Using Photon-counting Detector CT with Reduced Contrast Media Volume

Purpose

To develop and evaluate a low-volume contrast media protocol for thoracoabdominal CT angiography (CTA) with photon-counting detector (PCD) CT.

Materials and Methods

This prospective study included consecutive participants (April-September 2021) who underwent CTA with PCD CT of the thoracoabdominal aorta and previous CTA with energy-integrating detector (EID) CT at equal radiation doses. In PCD CT, virtual monoenergetic images (VMI) were reconstructed in 5-keV intervals from 40 to 60 keV. Attenuation of the aorta, image noise, and contrast-to-noise ratio (CNR) were measured, and subjective image quality was rated by two independent readers. In the first group of participants, the same contrast media protocol was used for both scans. CNR gain in PCD CT compared with EID CT served as the reference for contrast media volume reduction in the second group. Noninferiority analysis was used to test noninferior image quality of the low-volume contrast media protocol with PCD CT.

Results

The study included 100 participants (mean age, 75 years ± 8 [SD]; 83 men). In the first group (n = 40), VMI at 50 keV provided the best trade-off between objective and subjective image quality, achieving 25% higher CNR compared with EID CT. Contrast media volume in the second group (n = 60) was reduced by 25% (52.5 mL). Mean differences in CNR and subjective image quality between EID CT and PCD CT at 50 keV were above the predefined boundaries of noninferiority (-0.54 [95% CI: -1.71, 0.62] and -0.36 [95% CI: -0.41, -0.31], respectively).

Conclusion

CTA of the aorta with PCD CT was associated with higher CNR, which was translated into a low-volume contrast media protocol demonstrating noninferior image quality compared with EID CT at the same radiation dose.Keywords: CT Angiography, CT-Spectral, Vascular, Aorta, Contrast Agents-Intravenous, Technology Assessment© RSNA, 2023See also the commentary by Dundas and Leipsic in this issue.

The effect of suprarenal graft fixation during EVAR on short- and long-term renal function

OBJECTIVE

The effect of suprarenal fixation (SR) compared to infrarenal fixation (IR) on renal function during endovascular aneurysm repair (EVAR) remains controversial. This study aims to compare the renal outcomes between fixation types in short- and long-term follow-up.

METHODS

Patients undergoing EVAR for infrarenal abdominal aortic aneurysm between 2005 and 2013 were included. Estimated glomerular filtration rate (eGFR) was measured at baseline and during a follow-up of 5 years. A decline in renal function was defined as a ≥ 20% decrease in eGFR. Changes in eGFR were compared between SR and IR groups at 1-7 days, 30 days, and 1-5 years postoperatively. Preoperative renal insufficiency was defined as eGFR < 60mL/min/1.73m², and those patients were included in the subanalyses.

RESULTS

A total of 358 patients were included. Among these, 267 (74.6%) had SR and 91 (25.4%) had IR fixation. A decline in renal function occurred more commonly after SR than after IR in 1-7 days postoperatively (p = .009), but no difference was noticed at 30 days and 1-5 years. Regardless of the fixation method, renal function steadily decreased steadily over time after EVAR (estimate -3.13 per a year, 95% confidence interval -3.40- -2.85, p < .001). Patients with pre-existing renal insufficiency were included in subgroup analyses, and those with SR were more often found to have a decline in eGFR 5 years postoperatively than their counterparts with IR (59.5% vs 20.0%, p = .036).

CONCLUSION

An immediate postoperative decline in renal function was seen more often after SR fixation than IR fixation but this difference was transient. SR fixation is a safe method for patients with normal renal function. Long-term results seems to favor IR over SR in patients with pre-existing renal insufficiency.

Predictors of Decline in Renal Function 5 Years after EVAR

INTRODUCTION

While there exists copious short-term data regarding renal function following infra-renal endovascular abdominal aortic aneurysm repair (EVAR), long-term analysis is sparse. This is a single institution retrospective review of predictors of renal function decline 5 years after elective EVAR.

METHODS

All EVAR between 2007 and 2015 were queried. Patients in whom renal function was documented 5 years postoperatively were included in analysis. Exclusion criteria were ruptured aneurysm, mortality before 56 months, lack of follow-up, ESRD status, and concomitant renal intervention. The primary outcome investigated was a 20% or greater drop in glomerular filtration rate (GFR) 5 years postoperatively. The following variables at the time of surgery were investigated as potential predictors: age, gender, hypertension, hyperlipidemia, diabetes, CAD or prior MI, COPD, prior stroke, baseline eGFR under 60 mL/min/1.73 m², supra-renal fixation, infra-renal fixation, neck diameter, neck length, and number of contrast CT.

RESULTS

354 EVAR were identified of which 143 met inclusion criteria (211 excluded). Univariate analysis revealed female gender (OR 2.7), hypertension (OR 9.4), baseline renal insufficiency (OR 3.8), larger neck diameter, and supra-renal fixation (OR 2.32) all predictive (P < .05) of GFR drop at 5 years. Multivariate binary logistic regression analysis found female gender (multivariate OR 3.9, P = .023) and baseline renal insufficiency (multivariate OR 3.0, P = .029) as significant predictors of greater than 20% GFR drop at 5 years. Only 2 patients of the 143 progressed to dialysis requirement at 5 years.

CONCLUSIONS

Females and patients with baseline renal insufficiency are more vulnerable to significant decline in renal function 5 years following EVAR. Consistent with analogous literature, supra-renal fixation appears moderately deleterious toward renal function with no clinical significance in those with baseline normal renal function. The potential benefit of avoidance of supra-renal fixation in female patients with baseline renal insufficiency is worth further investigation in a more robust multi-center study.

Diseases of the Aorta and Kidney Disease: Conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference

Chronic kidney disease (CKD) is an independent risk factor for the development of abdominal aortic aneurysm (AAA), as well as for cardiovascular and renal events and all-cause mortality following surgery for AAA or thoracic aortic dissection. In addition, the incidence of acute kidney injury (AKI) after any aortic surgery is particularly high, and this AKI per se is independently associated with future cardiovascular events and mortality. On the other hand, both development of AKI after surgery and the long-term evolution of kidney function differ significantly depending on the type of AAA intervention (open surgery vs. the various subtypes of endovascular repair). Current knowledge regarding AAA in the general population may not be always applicable to CKD patients, as they have a high prevalence of co-morbid conditions and an elevated risk for periprocedural complications. This summary of a Kidney Disease: Improving Global Outcomes Controversies Conference group discussion reviews the epidemiology, pathophysiology, diagnosis, and treatment of Diseases of the Aorta in CKD and identifies knowledge gaps, areas of controversy, and priorities for future research.

Central and peripheral arterial diseases in chronic kidney disease: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference

Chronic kidney disease (CKD) affects about 10% of all populations worldwide, with about 2 million people requiring dialysis. Although patients with CKD are at high risk of cardiovascular disease and events, they are often underrepresented or excluded in clinical trials, leading to important knowledge gaps about how to treat these patients. KDIGO (Kidney Disease: Improving Global Outcomes) convened the fourth clinical Controversies Conference on the heart, kidney and vasculature in Dublin, Ireland, in February 2020, entitled Central and Peripheral Arterial Diseases in Chronic Kidney Disease. A global panel of multidisciplinary experts from the fields of nephrology, cardiology, neurology, surgery, radiology, vascular biology, epidemiology, and health economics attended. The objective was to identify key issues related to the optimal detection, management, and treatment of cerebrovascular diseases, central aortic disease, renovascular disease, and peripheral artery disease in the setting of CKD. This report outlines the common pathophysiology of these vascular processes in the setting of CKD, describes best practices for their diagnosis and management, summarizes areas of uncertainty, addresses ongoing controversial issues, and proposes a research agenda to address key gaps in knowledge that, when addressed, could improve patient care and outcomes.

Comparison of renal function after Endovascular Aneurysm Repair and Open Aneurysm Repair in patients treated with abdominal aortic aneurysm below the renal artery

INTRODUCTION

In addition to open endoaneurysmorrhaphy (EA) for treating the abdominal aortic aneurysm (AAA), other approaches such as endovascular aneurysm repair (EVAR) is gaining attention. Renal dysfunction could be a complication of these surgical techniques. We decided to compare renal function in EVAR vs. EA in patients operated for infrarenal AAAs.

METHODS

Two groups of patients with AAA were included in this retrospective study. The first group (28 cases) consisted of patients who underwent AAA repair by EA technique and the second group included 12 patients who underwent EVAR for AAA repair. Serum creatinine levels measured one week, one month, three months, six months, and one year after the surgeries were documented. Through calculating the glomerular filtration rate (GFR) and scoring by the RIFLE criteria (Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease), the patients' renal function was evaluated.

RESULTS

Of 40 patients included, three cases had diabetes mellitus (7.5%), 16 cases had hypertension (40%), 16 were smokers (40%), and 12 cases had a ruptured AAA (30%). The mean time of onset or increase of renal dysfunction compared to baseline in both groups was 6.45 days. The lowest time for patients with renal dysfunction (GFR less than 60) was from the onset and the highest time was 90 days after surgery. GFR of patients before surgery (76.9 in the EVAR group, vs. 56.2 in the EA group; P = 0.015) and one year after the surgery (84.1 in the EVAR group, vs. 57.7 in the EA group; P = 0.027) was differed significantly. The RIFLE criterion also was significantly different at the end of the first year in the two groups (P = 0.042).

CONCLUSION

Based on the results, we concluded that the changes in renal function in EA group were more than EVAR group during one year. It may be necessary to follow patients undergoing these surgeries for a longer period to understand the prognosis of these patients better.

Computed Tomography Angiography of the Aorta-Optimization of Automatic Tube Voltage Selection Settings to Reduce Radiation Dose or Contrast Medium in a Prospective Randomized Trial

OBJECTIVES

The aim of this study was to compare the image quality of low-kV protocols with optimized automatic tube voltage selection (ATVS) settings to reduce either radiation dose or contrast medium (CM) with that of a reference protocol for computed tomography angiography (CTA) of the thoracoabdominal aorta.

MATERIALS AND METHODS

In this institutional review board-approved, single-center, prospective randomized controlled trial, 126 patients receiving CTA of the aorta were allocated to one of three computed tomography protocols: (A) reference protocol at 120 kVp and standard weight-adapted CM dose; (B) protocol at 90 kVp, reduced radiation and standard CM dose; and (C) protocol at 90 kVp, standard radiation and reduced CM dose. All three protocols were performed on a third-generation dual-source computed tomography scanner using the semimode of the ATVS system. The image-task-dependent optimization settings of the ATVS (slider level) were adjusted to level 11 (high-contrast task) for protocols A and B and level 3 (low-contrast task) for protocol C. Radiation dose parameters were assessed. The contrast-to-noise ratios (CNRs) of protocols B and C were tested for noninferiority compared with A. Subjective image quality was assessed using a 5-point Likert scale.

RESULTS

Size-specific dose estimate was 34.3% lower for protocol B compared with A (P < 0.0001). Contrast medium was 20.2% lower for protocol C compared with A (P < 0.0001). Mean CNR in B and C was noninferior to protocol A (CNR of 30.2 ± 7, 33.4 ± 6.7, and 30.5 ± 8.9 for protocols A, B, and C, respectively). There was no significant difference in overall subjective image quality among protocols (4.09 ± 0.21, 4.03 ± 0.19, and 4.08 ± 0.17 for protocols A, B, and C, respectively; P = 0.4).

CONCLUSIONS

The slider settings of an ATVS system can be adjusted to optimize either radiation dose or CM at noninferior image quality in low-kV CTA of the aorta. This optimization could be used to extend future ATVS algorithms to take clinical risk factors like kidney function of individual patients into account.

Acute kidney injury following endovascular intervention for peripheral artery disease

BACKGROUND

The incidence of, and risk factors for, acute kidney injury (AKI) after endovascular intervention for peripheral artery disease (PAD) remain unknown. The aim of this study was to assess the proportion of patients who develop AKI and explore the risk factors.

METHODS

Prospectively collected data on patients undergoing femoropopliteal endovascular intervention for symptomatic PAD across three vascular centres were analysed. The proportion of patients developing AKI (according to the Kidney Disease Improving Global Outcomes definition) within 48 h, and the proportion developing the composite Major Adverse Kidney Events (MAKE) endpoints (death, dialysis, drop in estimated glomerular filtration rate at least 25 per cent) at 30 days (MAKE30) and remains 90 days (MAKE90) were calculated. Multivariable regression analysis was used to assess predictors of AKI, and the association between AKI and death.

RESULTS

Some 2041 patients were included in the analysis. AKI developed in 239 patients (11.7 per cent), with 47 (2.3 per cent) requiring dialysis within 30 days, and 18 (0.9 per cent) requiring ongoing dialysis. The MAKE30 and MAKE90 composite endpoints were reached in 358 (17.5 per cent) and 449 (22.0 per cent) patients respectively. Risk factors for AKI were age, sex, congestive heart failure, chronic limb-threatening ischaemia, emergency procedure, and pre-existing chronic kidney disease. AKI, dementia, congestive heart failure, and major amputation were risk factors for medium-term mortality.

CONCLUSION

AKI is a common complication after intervention for PAD and is associated with medium-term mortality.

Time-to-Event Analysis of the Impact of Endovascular Aortic Aneurysm Repair on Chronic Renal Decline

BACKGROUND

Although randomized studies have revealed the long-term outcomes of the endovascular repair (ER) of abdominal aortic aneurysm (AAA) compared to open repair (OR), there is controversy surrounding chronic renal decline (CRD) after ER. This study reviewed our propensity-matched cohorts of ER and OR to compare CRD rates using a time-to-event analysis. The ER groups undergoing suprarenal (SR) or infrarenal (IR) proximal fixation were also compared with the OR group.

METHODS

This retrospective review of infrarenal AAA repair was conducted from June 2007-December 2017. Patients with ≥1 year of follow-up were included. Cases of supra/pararenal AAAs, infectious AAAs, rupture, or severe chronic kidney disease (CKD) (estimated glomerular filtration rate (eGFR) <15 mL/min/1.73 m² or dependence on renal replacement therapy) were excluded. CRD was defined as eGFR decline of >20% or de novo hemodialysis during follow-up. Patients treated with ER (ER group) and OR (OR group) were propensity-score matched for age, sex, comorbidities, ejection fraction, respiratory function, and baseline eGFR. Kaplan-Meier analysis compared the freedom from CRD rates of the matched cohorts (mER and mOR groups). Patients treated with SR and IR fixation devices (SR and IR groups) were also separately matched to the OR group, followed by analysis.

RESULTS

In total, 1087 patients underwent elective AAA repair. Among them, 944 (512 ER and 432 OR) were enrolled. The ER group was older than the OR group (median age 79 vs 71; P<0.001). The ER group had significantly lower baseline eGFR and more comorbidities than the OR group. Among 187 propensity-score matched pairs (187 mER and 187 mOS patients), background characteristics, including age and baseline eGFR, were comparable, but median renal function follow-up was significantly longer in the mER group than in the mOR group (48 vs 26 months; P<0.001). CRD was observed in 57 patients in the mER group and 30 patients in the mOR group. Kaplan-Meier analysis of the freedom from CRD showed no significant difference between the matched groups (P=0.268); however, in the later follow-up of >4 years, CRD was more common in the mER group. The matched analyses between the OR group and specific fixation groups, comprising 102 OR-SR and 73 OR-IR pairs, demonstrated no significant differences in CRD.

CONCLUSIONS

Compared to OR, there was no significant impact of ER on CRD at up to 4 years, supporting the safety of ER in terms of the mid-term renal outcome of our present clinical practice.

Platelet Count Recovery after Endovascular Aneurysm Repair for Abdominal Aortic Aneurysm

Objective: To find a new predictor of endoleak (EL) and aneurysm sac expansion after endovascular aneurysm repair (EVAR), we evaluated the platelet count recovery (PCR) process after EVAR.

Materials and Methods: Two hundred five patients treated with elective EVAR from 2007 to 2015 were retrospectively analyzed. We compared the platelet count ratio until postoperative day (POD) 7 to the presurgical baseline between patients with and without persistent EL (≥ 6 months). Subsequently, we calculated the optimal platelet count ratio for distinguishing persistent EL using receiver-operating characteristics analysis. A platelet count ratio on POD7 ≥118% was defined as the PCR. We evaluated the PCR’s influence on the cumulative aneurysm sac expansion rate.

Results: The average platelet count ratio on POD7 rose above baseline (112%), and the ratio was attenuated by persistent EL (103%). Of 205 patients, 126 (61%) were assigned to the disturbed PCR group (PCR(−) group). Cumulative aneurysm sac expansion rate was higher in the PCR(−) group than the PCR(+) group (34.4% vs. 12.8% in 5 years, p=0.01).

Conclusion: Disturbed PCR after EVAR may be associated with ELs and eventual aneurysm sac expansion.

Risk of renal failure and death when renal arteries are involved in endovascular aortic aneurysm repair

OBJECTIVE

Endovascular abdominal aortic repair can involve the incorporation of renal arteries. Revascularization after intentional or unintentional renal artery (RA) coverage is not always technically successful, and the loss of a single RA may result in the need for postoperative dialysis. Thus, we compared the outcomes after endovascular aneurysm repair (EVAR) stratified by RA involvement (RAI).

METHODS

Patient data from the Vascular Quality Initiative from 2009 to 2018 registry were analyzed. The exclusion criteria were preoperative dialysis, missing RAI data, and repair above the superior mesenteric artery. The repair type cohorts were defined as (1) no RAI (NRAI), (2) RAI with revascularization (RAI-R), and (3) RAI with no revascularization (RAI-NR). A sensitivity analysis was performed by excluding ruptured presentations. The primary outcome was the need for postoperative dialysis. The secondary outcomes were 30-day mortality, dialysis at follow-up, postoperative renal function, and 2-year survival. Multivariate analysis was used to determine the independent predictors for postoperative dialysis. The 2-year survival analysis was performed using Kaplan-Meier log-rank test.

RESULTS

Of 54,020 patients in the EVAR and TEVAR (thoracic EVAR)/complex EVAR modules in the Vascular Quality Initiative, 25,724 met the criteria for inclusion (NRAI, n = 24,879; RAI-R, n = 733; RAI-NR, n = 112). The demographics and comorbidities were similar among the three groups. The RAI-NR group had more frequently had ruptured or symptomatic aneurysms. The postoperative dialysis requirement was higher in the RAI-NR group (NRAI, 0.7%; RAI-R, 2.2%; RAI-NR, 17%; P < .0001), as were the 30-day mortality and dialysis requirement at follow-up. On multivariate analysis, RAI-R (odds ratio [OR], 2.2; P = .03) and RAI-NR (OR, 5.9; P < .0001) were independent predictors of postoperative dialysis and remained so after excluding ruptured presentations (RAI-R: OR, 3; P = .003; RAI-NR: OR, 22.3; P < .0001). Other independent predictors of the need for postoperative dialysis were worse preoperative renal function, a symptomatic presentation, any preoperative or intraoperative blood transfusion, and larger blood loss (≥200 mL). Excluding those with rupture, the overall survival at 2 years on Kaplan-Meier analysis was lower for the RAI-NR group (NRAI, 92%; RAI-R, 89%; RAI-NR, 80%; P = .004).

CONCLUSIONS

RAI is highly predictive of the need for postoperative and permanent dialysis after EVAR. RAI-NR was associated with lower overall survival. These risks should be considered when planning and performing EVAR and should be weighed against the risks of open repair when considering the treatment options.

Impact of Accessory Renal Artery Coverage on Renal Function during Endovascular Aortic Aneurysm Repair

BACKGROUND

Long-term outcomes of accessory renal artery (ARA) coverage after endovascular aneurysm repair (EVAR) are unknown. We analyzed the impact of ARA coverage on renal function long-term.

METHODS

This retrospective, monocentric study included patients treated by EVAR between 2008 and 2016. Patients with at least one ARA covered with EVAR (ARA group) were compared with patients with no covered ARA (control group). Renal function was determined by estimating the glomerular filtration rate (eGFR) and graded according to chronic kidney disease (CKD) classification stages.

RESULTS

A total of 184 patients were included (ARA group, n = 25; control group, n = 159). Renal risk factors were similar in the 2 groups. Mean (±standard deviation) duration of follow-up was 41.6 ± 25.8 months. Preoperative eGFR (mL/min/1.73 m²) was 68.9 ± 17.8 in the ARA group and 72.5 ± 17.4 in the control group (P = 0.33), with a similar decline in the 2 groups during follow-up (-6.52 ± 11.6 ARA group vs. -6.43 ± 13.8 control group; P = 0.97). At the end of the study, 8 ARA patients and 56 controls had deteriorated by one CKD stage (32% vs. 35.2%, respectively; P = 0.75). Rate of renal infarction was significantly higher in the ARA group (96% vs. 1.9%; P < 0.0001). In multivariate analysis, suprarenal fixation was identified as a risk factor for a decline in renal function (odds ratio = 2.01 [95% confidence interval: 1.05-3.84]; P = 0.04).

CONCLUSIONS

ARA coverage after EVAR does not appear to affect renal function long-term. Suprarenal fixation led to a greater decline in renal function.

Early Postoperative Renal Dysfunction Predicts Long-Term Renal Function Degradation after Type IV Thoracoabdominal Aortic Aneurysm Surgical Repair

BACKGROUND

Type IV thoracoabdominal aortic aneurysm surgical repair is often complicated by postoperative acute kidney injury. The aim was to evaluate early renal injury influence on long-term renal function.

METHODS

All type IV thoracoabdominal surgical repair performed between January 2000 and January 2014 in our tertiary hospital were included in this retrospective observational study. All procedures were performed through a retroperitoneal approach with at least suprarenal aortic cross-clamping. Cold Ringer Lactate was used to perfuse the kidneys. Serum creatinine (Scr.) and glomerular filtration rate (GFR) were recorded preoperatively, daily until discharge and at least annually during follow-up. Postoperative renal dysfunction was classified using the RIFLE score. Predictors of long-term renal decline were identified by logistic regression and a Cox model.

RESULTS

Of total, 80 patients were included. Aortic clamping level was suprarenal (10%), supramesenteric (37%) or supracoeliac (53%). Ischemic durations were 29 ± 9 min for the gastrointestinal tract and the right kidney, 54 ± 28 min for the left kidney. Three patients died postoperatively. At discharge, 31 (38.8%) patients did not have a postoperative renal impairment (RIFLE-), compared with 49 (61.2%) who had a renal dysfunction (RIFLE+). GFR was 89 ± 29 ml/min vs 68 ± 37 ml/min, respectively (P < 0.01). In the RIFLE + group, Scr. was increased by x1.5 (Risk) for 22 patients, x2 (Injury) for 19 patients, and ×3 (Failure) for 8 patients. Mean follow-up was 59 months. Eighteen patients died, and 2 patients started permanent dialysis at 46 and 118 months during follow-up. The only predictive factor of long-term GFR degradation was a postoperative GFR below 45 ml/min (OR: 16.5; 95%; P < 0.001).

CONCLUSIONS

Postoperative renal dysfunction was a frequent complication, associated with long-term renal function degradation.

To assess hemodynamic disturbances to the ostia of the renal arteries generated by the implantation of EVAR with a suprarenal fixation

INTRODUCTION

The treatment of abdominal aortic aneurysm (AAA) is increasingly performed via endovascular aneurysm repair (EVAR). Different types of fixation are possible with EVAR, i.e., below (infrarenal fixation) or above (suprarenal fixation) the renal arteries. Hemodynamic alterations in renal arterial flow with suprarenal (SR) fixation remain to be demonstrated. The IFIXEAR (Impact of Supra-renal Fixation of EVAR on Hemodynamics of Renal Arteries) study is designed to assess the hemodynamic effects at the ostia of at least 1 renal artery, generated immediately post-surgery by the implantation of an aortic stent with SR fixation.

METHODS

IFIXEAR is a prospective, 2 center study. Every patient undergoing elective EVAR with SR fixation is eligible for inclusion. Patients with previous hemodynamic disturbances to the ostia of 1 of the renal arteries are not eligible. All patients undergo echocardiography and renal arteries duplex ultrasound within a month before surgery, and at 1 and 12 months after surgery. The primary endpoint is hemodynamic disturbance, defined as a peak systolic velocity greater than 120 cm/second, at the ostia of 1 of the renal arteries in the immediate postoperative period.

ETHICS AND DISSEMINATION

The study was approved by the Ethics Committee "Comité de Protection des Personnes Ouest V" under the number 18/019-2 on April 20, 2018. All patients provide written informed consent before inclusion. The University Hospital of Besancon is the trial sponsor. Results of the study will be submitted for publication in a peer-reviewed international medical journal.

REGISTRATION

The trial is registered with ClinicalTrials.gov (Identifier: NCT03594786, principal investigator: Dr Patricia Costa, Registered on April 24, 2018).

The Clinical Utility and Assessment of Renal Biomarkers in Acute Kidney Injury After Abdominal Endovascular Aneurysm Repair. A Systematic Review

The widespread adoption of endovascular aneurysm repair (EVAR) for abdominal aortic aneurysms (AAA) is due to the obvious advantages of the procedure compared to the traditional open repair. However, these advantages have to be weighed against the increased risk of renal dysfunction with EVAR. The evaluation of the perioperative renal function after EVAR has been hampered by the lack of sensitive and specific biochemical markers of acute kidney injury (AKI). The purpose of this study was to summarize all novel renal biomarkers and to evaluate their clinical utility for the assessment of the kidney function after EVAR. A systematic review of the current literature, as the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement guidelines, was performed to identify relevant studies with novel renal biomarkers and EVAR. Pubmed and Scopus databases were systemically searched. Studies reporting on thoracic endovascular aortic repair (TEVAR), case reports, case series, letters to the editor, and systematic reviews were excluded. Neutrophil-Gelatinase-Associated Lipocalin, Cystatin C, Liver-type fatty-acid-binding protein were the most common among the eligible studies while Interleukin-18, Retinol binding protein, N-acetyle-b-D-glucosaminidase and microalbumin have a sparse appearance in the literature. These biomarkers have been assessed in plasma as well as urine samples with each sample material having its own advantages and drawbacks. Which of these biomarkers has the most potential for assessing postoperative renal failure after EVAR, remains to be proved. The few studies presented in the literature show the potential clinical utility of these biomarkers, but larger studies with longer follow-up are required to determine the precise relationship between these biomarkers and postoperative acute kidney injury.

Outcomes after treatment of complex aortic abdominal aneurysms with the fenestrated Anaconda endograft

OBJECTIVE

To date, information on the fenestrated Anaconda endograft is limited to case series with a small sample size. This study was performed to assess the technical and clinical outcome of this device in a large international case series.

METHODS

All worldwide centers having treated more than 15 complex abdominal aortic aneurysms (AAA) or type IV thoracoabdominal aortic aneurysm patients with the fenestrated Anaconda endograft were approached. Main outcome parameters were procedural technical success, postoperative and follow-up clinical outcome for endoleaks, target vessel patency, reintervention rate, and patient survival.

RESULTS

Three hundred thirty-five consecutive cases treated between June 2010 and May 2018 in 11 sites were included. Patients were treated for a short neck infrarenal (n = 98), juxtarenal (n = 191), suprarenal AAA (n = 27), or type IV thoracoabdominal aortic aneurysm (n = 19). Mean age was 73.6 ± 4.6 years (292 male). Endografts contained a total of 920 fenestrations, with a mean of 2.7 ± 0.8 fenestrations per case. Technical success was 88.4% (primary, 82.7%; assisted primary 5.7%). In 6.9% of cases, a procedural type IA endoleak was observed, spontaneously disappearing in 82.6% during early follow-up. The development of a type IA endoleak was associated with greater neck angulation (odds ratio [OR], 0.94; P = .01), three fenestrations (OR, 42.7; P = .01) and the presence of augmented proximal rings (OR, 0.17; P = .03). Median follow-up was 1.2 years (interquartile range, 0.4-2.6). The mean estimated glomerular filtration rate deteriorated from 67.6 ± 19.3 mL/min/1.73 m² preoperatively to 59.3 ± 22.7 mL/min/1.73 m² at latest follow-up (P = .00). The freedom from AAA growth were 97.9 ± 0.9% (n = 190) and 86.4 ± 3.0% (n = 68), with a freedom from AAA rupture of 99.7 ± 0.3% (n = 191) and 99.1 ± 0.7% (n = 68), at 1 and 3 years, respectively. The endoleak-free survival, excluding spontaneously resolved procedural endoleaks, at 1 and 3 years was 73.4 ± 2.6 (n = 143) and 65.6 ± 3.4% (n = 45), respectively. The target vessel patency at one and three years were 96.4 ± 0.7% (n = 493) and 92.7 ± 1.4% (n = 156), respectively. A total of 75 reinterventions were done in 64 cases (19.1%), of which 25 cases for an endoleak. The reintervention-free survival at 1 and 3 years were 83.6 ± 2.2% (n = 190) and 71.0 ± 3.7% (n = 68), respectively. No deaths during procedure, extending within 24 hours postoperatively, were observed. Within 30 days 14 patients (4.2%) died and during follow-up another 39 patients (11.6%) died. Three deaths were considered AAA related (one rupture, one endograft infection, and one bilateral renal artery occlusion). The estimated cumulative survival at 1 and 3 years were 89.8 ± 1.8% (n = 191) and 79.2 ± 3.0% (n = 68), respectively.

CONCLUSIONS

The custom-made fenestrated Anaconda endograft is a valuable option for the treatment of a complex AAA. A procedural type IA endoleak is seen relatively frequently, but spontaneously resolves in most cases.

Partial Renal Coverage after Endovascular Aortic Aneurysm Repair with Suprarenal Fixation Seems Not to be Associated with Early Renal Impairment

BACKGROUND

Efforts to achieve optimal seal during endovascular aortic aneurysm repair (EVAR) may produce partial coverage of the lowest renal artery and in some cases even occlusion. This coverage might alter the renal ostial flow, which could finally affect renal function. We sought to evaluate the incidence of renal ostium coverage and its possible effects on renal function.

METHODS

All patients undergoing elective EVAR with suprarenal fixation devices between January 2014, and December 2017, at our institution were identified. Patients with preoperative and postoperative computed tomography angiography (CTA), as well as the preoperative, postoperative, and one year postintervention creatinine levels and estimated glomerular filtration rate (eGFR) were included in the present study. Patients in hemodialysis, with a preoperative eGFR <30 mL/min, urgent EVAR, neck adjunctive procedures, excessive aortic thrombus, or procedure-related reintervention were excluded.

RESULTS

A total of 127 patients received EVAR for aortoiliac aneurysmatic pathologies between January 2014, and December 2017. Forty-three of them met the inclusion criteria having a median follow-up of 18.8 months (range; 12.0-53.9). Twenty-six (60.5%) patients presented at least one criterion of hostile neck condition and 23 (53.5%) had a preoperative eGFR <60 mL/min. The average distance from the proximal endograft fabric to the lower renal artery was 1.5 mm (range, 0.0-6.0) while a total of 15 renal ostia (34.9%) suffered unintended partial coverage (range, 20 to 75% of the renal ostium) in the postoperative CTA. Nine of these patients (60%) had a hostile neck condition. Eight patients (18.6%) suffered significant deterioration (>20% of the eGFR), 27 patients (62.8%) maintained their renal function and 8 (18.6%) presented an improvement of the eGFR in the latest available blood sample. Renal function impairment showed no significant association with renal ostium coverage (P = 0.561), hostile neck condition (P = 0.973), or the diameter of the renal artery (P = 0.835). In the subgroup analysis, patients with the eGFR <60 mL/min did not show significantly greater renal function deterioration (P = 0.568).

CONCLUSIONS

Partial renal coverage is not an uncommon phenomenon occurring in one-third of the treated patients. However, it was not associated with renal function impairment in the early term. Further studies with longer follow-up are needed to confirm our results in the long haul.

Meta-analysis of Renal Function Following Infrarenal EVAR using Suprarenal or Infrarenal Fixation Devices

OBJECTIVE/BACKGROUND

The effect of suprarenal (SR) as opposed to infrarenal (IR) fixation on renal outcomes post-endovascular aneurysm repair (EVAR) remains controversial. This meta-analysis aims to update current understanding of this issue.

METHODS

A prior meta-analysis was updated through a Preferred Reporting Items for Systematic reviews and Meta-Analyses search for additional studies published in the last 3 years reporting on renal dysfunction or related outcomes post-EVAR. Random effects meta-analysis was undertaken using SPSS.

RESULTS

A total of 25 non-randomised studies comparing SR with IR fixation were included, totalling 54,832 patients. In total, 16,634 underwent SR and 38,198 IR. Baseline characteristics, including age, baseline estimated glomerular filtration rate, diabetes, cardiac disease, and smoking, were similar between the groups. There was a small but significant difference in outcomes for renal dysfunction at the study end point (SR 5.98% vs. IR 4.83%; odds ratio [OR] 1.29, 95% confidence interval [CI] 1.18-1.40 [p < .001]); however, at 30 days and 12 months there was no significant difference, and this did not hold up to sensitivity analysis. Incidence of renal infarcts (SR 6.6% vs. IR 2.3%; OR 2.78, 95% CI 1.46-5.29 [p = .002]), renal stenosis (SR 2.4% vs. IR 0.8%; OR 2.89, 95% CI 1.00-8.38 [p = .05]), and renal artery occlusion (SR 2.4% vs. IR 1.2%; OR 2.21, 95% CI 1.15-4.25 [p = 0.02]) favoured IR fixation; however, there was no difference in haemodialysis rates.

CONCLUSION

This meta-analysis has identified small but significantly worse renal outcomes in patients having SR fixation devices compared with IR; however, there was no difference in dialysis rates and a small effect on renal dysfunction, which did not stand up to rigorous sensitivity analysis. This should be taken into consideration during graft selection, and further studies must assess renal outcomes in the longer term, and in those with pre-existing renal dysfunction.

Flow and wall shear stress characterization after endovascular aneurysm repair and endovascular aneurysm sealing in an infrarenal aneurysm model

BACKGROUND

Endovascular aneurysm repair (EVAR) with a modular endograft has become the preferred treatment for abdominal aortic aneurysms. A novel concept is endovascular aneurysm sealing (EVAS), consisting of dual endoframes surrounded by polymer-filled endobags. This dual-lumen configuration is different from a bifurcation with a tapered trajectory of the flow lumen into the two limbs and may induce unfavorable flow conditions. These include low and oscillatory wall shear stress (WSS), linked to atherosclerosis, and high shear rates that may result in thrombosis. An in vitro study was performed to assess the impact of EVAR and EVAS on flow patterns and WSS.

METHODS

Four abdominal aortic aneurysm phantoms were constructed, including three stented models, to study the influence of the flow divider on flow (Endurant [Medtronic, Minneapolis, Minn], AFX [Endologix, Irvine, Calif], and Nellix [Endologix]). Experimental models were tested under physiologic resting conditions, and flow was visualized with laser particle imaging velocimetry, quantified by shear rate, WSS, and oscillatory shear index (OSI) in the suprarenal aorta, renal artery (RA), and common iliac artery.

RESULTS

WSS and OSI were comparable for all models in the suprarenal aorta. The RA flow profile in the EVAR models was comparable to the control, but a region of lower WSS was observed on the caudal wall compared with the control. The EVAS model showed a stronger jet flow with a higher shear rate in some regions compared with the other models. Small regions of low WSS and high OSI were found near the distal end of all stents in the common iliac artery compared with the control. Maximum shear rates in each region of interest were well below the pathologic threshold for acute thrombosis.

CONCLUSIONS

The different stent designs do not influence suprarenal flow. Lower WSS is observed in the caudal wall of the RA after EVAR and a higher shear rate after EVAS. All stented models have a small region of low WSS and high OSI near the distal outflow of the stents.

Assessment of Renal Injury in Patients Undergoing Elective EVAR Using Urinary Neutrophil Gelatin-Associated Lipocalin, Interleukin 18, and Retinol-Binding Protein

Acute kidney injury (AKI) is a recognized complication post-endovascular aneurysm repair (EVAR). Neutrophil gelatin-associated lipocalin (NGAL), interleukin 18 (IL-18), and retinol-binding protein are emerging urinary biomarkers that have shown promise in detecting subclinical and clinical renal impairment. In this study, we assessed changes in these urinary biomarkers as well as serum creatinine (SCr) in patients undergoing EVAR. Urine samples were collected prospectively at 5 time points for each recruited patient: pre-EVAR (baseline) and 6, 12, 24, and 48 hours after the procedure for serial assessment of urinary biomarkers. Serum creatinine was quantified preoperatively and at 24 and 48 hours postoperatively. Serial changes of urinary biomarkers and SCr were assessed. A significant increase in NGAL and IL-18 from baseline was observed ( P < .05), as early as 6 hours for NGAL. A significant rise in levels of NGAL and IL-18 precedes the significant rise in SCr. These findings highlight the potential of emerging urinary biomarkers in detecting early AKI following EVAR.

Endovascular Management of Abdominal Aortic Aneurysms: the Year in Review

OPINION STATEMENT

Endovascular aneurysm repair (EVAR) has become the predominant method of treatment for abdominal aortic aneurysms (AAA). The use of conscious sedation with local anesthesia and percutaneous femoral access has further decreased the morbidity of the procedure. Current devices can more effectively manage increasingly "hostile" aneurysm necks, while chimney grafts or dedicated fenestrated stent-grafts can be used for juxta-renal disease with favorable results. However, endovascular repair does present a new set of challenges, and endoleaks remain an area of concern. While there is general consensus that type I and type III endoleaks require treatment, type II endoleaks are the topic of ongoing research and debate. Development of devices and techniques to prevent and treat endoleak continues to progress. Advances in contrast-enhanced ultrasound are reducing reliance on computed tomography for post-operative monitoring. This is an important step in this population at high risk for the development of kidney failure. Despite these many innovations, further research is needed to optimize the care of patients with AAA.