Endovascular aneurysm repair (EVAR)– and transcatheter aortic valve replacement (TAVR)–associated acute kidney injury

Acute kidney injury in patients undergoing endovascular or open repair of juxtarenal or pararenal aortic aneurysms

BACKGROUND

The aim of this cohort study was to report the proportion of patients who develop periprocedural acute kidney injury (AKI) after endovascular repair (ER) and open surgery (OS) in patients with juxta/pararenal abdominal aortic aneurysm and to assess potential risk factors for AKI. The study also aimed to report the short- and long-term outcomes of patients with and without AKI.

METHODS

This was a multicenter cohort study of five European academic high-volume centers (>50 OS or 50 ER infrarenal AAA repairs, plus >15 complex AAA repairs per year). All consecutively treated patients were extracted from a prospective vascular surgical registry and the data were scrutinized retrospectively. The primary end point for this study was the development of AKI. AKI was diagnosed when there is a two-fold increase of serum creatinine or decrease of glomerular filtration rate of >50% within 1 week of AAA repair. Secondary end points included long-term mortality and end-stage renal disease (ESRD).

RESULTS

AKI occurred in 16.6% of patients in the ER group vs 30.3% in the OS group (P < .001). The 30-day mortality rate was higher among patients with AKI in both ER (15.4% vs 3.1%; P = .006) and OS (13.2% vs 5.3%; P = .001) groups. Age, chronic kidney disease, presence of significant thrombus burden in the pararenal region, >1000 mL blood loss in ER group were associated with development of AKI. Age, diabetes mellitus, chronic kidney disease, presence of significant thrombus burden in the pararenal region, and a proximal clamping time of >30 minutes in the OS group were associated with the development of AKI, whereas renal perfusion during clamping was the protective factor against AKI development. After a median follow-up of 91 months, AKI was associated with higher mortality rates in both the ER group (58.9% vs 29.7%; P < .001) and the OS group (61.5% vs 27.3%; P < .001). After the same follow-up period, AKI was associated with a higher incidence of ESRD in both the ER group (12.8% vs 3.6%; P = .009) and the OS group (9.9% vs 2.9%; P < .001).

CONCLUSIONS

The current study identified important pre and postoperative factors associated with AKI after juxta/pararenal abdominal aortic aneurysm repair. Patients with postoperative AKI had significantly higher short- and long term mortality and higher incidence of ESRD than patients without AKI.

Reduction of contrast medium for transcatheter aortic valve replacement planning using a spectral detector CT: a prospective clinical trial

INTRODUCTION

This study investigated the use of dual-energy spectral detector computed tomography (CT) and virtual monoenergetic imaging (VMI) reconstructions in pre-interventional transcatheter aortic valve replacement (TAVR) planning. We aimed to determine the minimum required contrast medium (CM) amount to maintain diagnostic CT imaging quality for TAVR planning.

METHODS

In this prospective clinical trial, TAVR candidates received a standardized dual-layer spectral detector CT protocol. The CM amount (Iohexol 350 mg iodine/mL, standardized flow rate 3 mL/s) was reduced systematically after 15 patients by 10 mL, starting at 60 mL (institutional standard). We evaluated standard, and 40- and 60-keV VMI reconstructions. For image quality, we measured signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and diameters in multiple vessel sections (i.e., aortic annulus: diameter, perimeter, area; aorta/arteries: minimal diameter). Mixed regression models (MRM), including interaction terms and clinical characteristics, were used for comparison.

RESULTS

Sixty consecutive patients (mean age, 79.4 ± 7.5 years; 28 females, 46.7%) were included. In pre-TAVR CT, the CM reduction to 40 mL is possible without affecting the image quality (MRM: SNR: -1.1, p = 0.726; CNR: 0.0, p = 0.999). VMI 40-keV reconstructions showed better results than standard reconstructions with significantly higher SNR (+ 6.04, p < 0.001). Reduction to 30 mL CM resulted in a significant loss of quality (MRM: SNR: -12.9, p < 0.001; CNR: -13.9, p < 0.001), regardless of the reconstruction. Across the reconstructions, we observed no differences in the metric evaluation (p > 0.914).

CONCLUSION

Among TAVR candidates undergoing pre-interventional CT at a dual-layer spectral detector system, applying 40 mL CM is sufficient to maintain diagnostic image quality. VMI 40-keV reconstructions improve the vessel attenuation and are recommended for evaluation.

CLINICAL RELEVANCE STATEMENT

Contrast medium reduction to 40 mL in pre-interventional transcatheter aortic valve replacement CT using dual-energy CT maintains image quality, while 40-keV virtual monoenergetic imaging reconstructions enhance vessel attenuation. These results offer valuable recommendations for interventional transcatheter aortic valve replacement evaluation and potentially improve nephroprotection in patients with compromised renal function.

KEY POINTS

• Patients undergoing transcatheter aortic valve replacement (TAVR), requiring pre-interventional CT, are often multimorbid with impaired renal function. • Using a spectral detector dual-layer CT, contrast medium reduction to 40 mL is feasible, maintaining diagnostic image quality. • The additional application of virtual monoenergetic image reconstructions with 40 keV improves vessel attenuation significantly in clinical practice.

Simultaneous Transcatheter Aortic Valve Implantation and Endovascular Aneurysm Repair for Severe Aortic Stenosis and Symptomatic Abdominal Aortic Aneurysm: Mini Review

Background: The treatment of patients with severe aortic stenosis (SAS) who concomitantly present with abdominal aortic aneurysm (AAA) is not defined. Aortic valve replacement surgery, performed alone, increases the risk of AAA rupture. Transcatheter aortic valve replacement (TAVR) and endovascular abdominal aortic aneurysm repair (EVAR) in the same intervention, especially in high-risk patients, is a safe alternative. Purpose: We report a case of simultaneous endovascular treatment of SAS and AAA and a mini literature review of nineteen cases with similar characteristics. Research design: Case report and literature review. Data Collection: An electronic search of PubMed and Scopus was performed from inception to December 2023. Results: Nineteen case reports of simultaneous transcatheter aortic valve repair and endovascular aneurysm repair for SAS and symptomatic AAA were identified published in the literature. Conclusions: We regard the simultaneous endovascular approach to both pathologies as a promising treatment alternative for selected patients with severe aortic stenosis and abdominal aortic aneurysm. We highlight the need to conduct randomized clinical trials in this patient population.

Perioperative renal function change after transcatheter aortic valve replacement: A single-center retrospective study in China

BACKGROUND

In recent years, the kidney function after Transcatheter Aortic Valve Replacement (TAVR) has gradually become a hot spot that arouse extensive attention.Our study is aimed to evaluate the incidence and predictors of acute kidney recovery (AKR) after TAVR.

METHODS

A total of 102 patients undergoing TAVR in Beijing Anzhen Hospital from June 2021 to March 2022 were enrolled in our study. Patients were divided into AKR group (n = 54), unchanged group (n = 40) and acute kidney injury (AKI) group (n = 8) based on the percent change of estimated glomerular filtration rate (eGFR). Univariate analysis was used to compare the differences in general clinical characteristics and other related indicators between the three groups to analyze the risk factors of AKR.

RESULTS

The incidence of AKR was 53% (54/102) after TAVR. Multivariate analysis showed that the incidence of age and proportion of severe NYHA class (III or IV) was significantly higher in the AKR group while renal dysfunction (eGFR <60 mL/min/1.73 m2) was lower. Besides, fluid management/volume therapy was significantly different among the three groups.

CONCLUSIONS

AKR is a generalizable phenomenon occurring frequently after TAVR. The age, proportion of severe NYHA class and the baseline renal function are independent predictors of AKR events in patients with severe aortic stenosis undergoing TAVR.

Can HALP score predict post-contrast acute kidney injury and 6-year mortality in patients undergoing endovascular abdominal aneurysm repair?

BACKGROUND

The aim of this study is to investigate the relationship between HALP score and post-contrast acute kidney injury (PC-AKI) and average 6-year mortality in patients undergoing endovascular abdominal aortic aneurysm repair (EVAR).

METHODS

125 patients who underwent EVAR between January 2015 and December 2020 were included in our study. HALP score was calculated with the formula "hemoglobin × albumin × lymphocyte count/platelet count." In the first phase of the study, two groups were developed: those who developed PC-AKI and those who did not. In the second stage, statistical analysis was performed by creating two groups: average 6-year mortality and survivors group.

RESULTS

HALP score was found to be lower in the PC-AKI group [26.12 (14-61.54) versus 40.53 (7.22-103.61); p < .001]. Low HALP score was found to be both a dependent and independent predictor of the development of PC-AKI (p = .019). HALP score was also found to be lower in the mortality group compared to the survivors [28.97 (12.6-103.61) versus 40.81 (7.22-99) p = .004]. Low HALP score was found to be only a dependent predictor of mortality. The development of PC-AKI was found to be an independent predictor of mortality (p = .042).

CONCLUSIONS

The HALP score, which can be calculated with a simple formula, can be used to predict PC-AKI and medium-long-term mortality in EVAR patients.

A systematic review and meta-analysis of total endovascular versus hybrid repair for the treatment of thoracoabdominal aortic aneurysms

OBJECTIVE

Although open repair has been the traditional mainstay therapy for thoracoabdominal aortic aneurysms (TAAAs), it remains a surgical challenge. Recently, hybrid repair (HR) and total endovascular repair (TEVR) have emerged as viable alternatives in treating TAAAs. Thus, we aimed to compare the primary outcomes of in-hospital/30-day mortality, as well as secondary outcomes of postoperative complications including spinal cord ischemia, bowel ischemia, long-term dialysis, myocardial infarction and lower limb ischemia for HR vs TEVR for the treatment of TAAAs. We postulated that TEVR was associated with lower in-hospital and 30-day mortality and postoperative complication rates as compared with HR.

METHODS

Four scientific databases were searched from inception to November 18, 2021. Meta-analyses were performed for the primary and secondary outcomes. This study was conducted in adherence to the PRISMA guidelines.

RESULTS

The search yielded 3312 articles. After a two-stage selection process, five articles were included for final analysis. The in-hospital/30-day mortality rate for TEVR was significantly lower compared with HR (odds ratio [OR], 0.27; 95% confidence interval [CI], 0.20-0.36; P < .00001). TEVR was also associated with reduced bowel ischemia (OR, 0.22; 95% CI, 0.14 -0.35; P < .00001) and long-term dialysis (OR, 0.22; 95% CI, 0.16-0.29; P < .00001). There was, however, no difference in the incidence of spinal cord ischemia (OR, 1.26; 95% CI, 0.74-2.14; P = .39), stroke (OR, 0.65; 95% CI, 0.10-4.20; P = .65), myocardial infarction (OR, 0.60; 95% CI, 0.17-2.05; P = .41), and lower limb ischemia (OR, 0.67; 95% CI, 0.29-1.55; P = .35). Most study outcomes had low heterogeneity. Findings were also robust to sensitivity analysis.

CONCLUSIONS

Compared with the HR, TEVR of TAAAs were associated with lower in-hospital and 30-day mortality, bowel ischemia, and long-term dialysis.

Acute Kidney Injury and Mortality After Fenestrated Endovascular Aortic Repair

INTRODUCTION

Acute kidney injury (AKI) is a common complication following endovascular aortic repair (EVAR). An association of AKI with patient survival after fenestrated EVAR (FEVAR) is currently under investigation.

METHODS

Patients undergoing FEVAR between April 2013 and June 2020 were included in the study. AKI was defined according to acute kidney injury network criteria. Demographic and perioperative data, complications, and survival are reported for the study cohort. The data were analyzed to identify possible predictors of AKI.

RESULTS

Two hundred and seventeen patients underwent FEVAR during the study period. Survival at last follow-up (20.4 ± 20.1 mo) was 75.1%. Thirty patients experienced AKI (13.8%). Six of 30 patients with AKI (20%) died within 30 days or in-hospital and 1 (3.3%) progressed to hemodialysis. Within 1 y, renal function had recovered in 23 patients (76.7%). In-hospital mortality was higher in patients with AKI (20% versus 4.3%, P = 0.006). A higher rate of AKI was seen in patients in whom an intraoperative technical complication had been documented (38.5% versus 8.4%, P = 0.001).

CONCLUSIONS

Patients undergoing FEVAR are at risk of developing AKI, especially if they experience technical intraoperative complications. Most patients see recovery of renal function within the first 30 days to 1 y, but AKI remains associated with significantly increased in-hospital mortality.

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.

Randomised controlled trial to evaluate the effect of contrast material dilution on renal function in patients after endovascular aortic repair: rationale and design for the CULTURE trial

INTRODUCTION

Postoperative renal function decline is a major concern for thoracic endovascular aortic repair (TEVAR) and endovascular abdominal aortic repair (EVAR). Diluting contrast medium in the power injector may be helpful in reducing the risk of contrast-induced nephropathy, but it can also blur fluoroscopic vision during surgery. The quality of the current evidence is very low; thus, this study is designed to investigate the effect of contrast dilution in the power injector on renal function changes in patients after endovascular aortic repair.

METHOD AND ANALYSIS

The study is a prospective, single-blind, parallel, non-inferiority, randomised controlled trial with two independent cohorts: Cohort TEVAR and EVAR. Individuals will enter the appropriate cohort based on clinical interviews if they meet the eligibility criteria. Participants in Cohort TEVAR and EVAR will be randomly allocated to the intervention group (diluting contrast medium to 50% in the power injector) and control group (pure contrast medium in the power injector) separately in a 1:1 ratio. The primary study points consist of the proportion of patients who develop acute kidney injury within 48 hours after TEAVR or EVAR (first stage) and freedom of major adverse kidney events at 12 months after TEAVR or EVAR (second stage). The safety endpoint is freedom of all types of endoleaks at 30 days after TEVAR or EVAR. Follow-up will be conducted at 30 days and 12 months after intervention.

ETHICS AND DISSEMINATION

The trial was approved by the Ethics Committee on Biomedical Research, West China Hospital of Sichuan University (approval number: 20201290). The results of the study will be disseminated through publications in peer-reviewed journals and presentations at academic conferences.

TRIAL REGISTRATION NUMBER

Chinese Clinical Trial Registry (ChiCTR2100042555).

Dexmedetomidine reduces acute kidney injury after endovascular aortic repair of Stanford type B aortic dissection: A randomized, double-blind, placebo-controlled pilot study

STUDY OBJECTIVE

To determine the effect of dexmedetomidine on acute kidney injury (AKI) following endovascular aortic repair (EVAR) for Stanford type B aortic dissection (TBAD).

DESIGN

Randomized, double-blind, placebo-controlled, pilot study.

SETTING

University Hospital.

PATIENTS

102 TBAD patients undergoing EVAR procedures were enrolled. Patients with dissection involving aortic arch or renal artery were excluded.

INTERVENTIONS

Patients were randomly assigned, in a 1:1 ratio, to a dexmedetomidine group (intravenous dexmedetomidine 0.4 μg/kg/h immediately after anesthesia induction and 0.1 μg/kg/h after extubation, which was maintained until 24 h) or a normal saline control group.

MEASUREMENTS

The primary outcome was the incidence of AKI within the first two days after surgery, based on the Acute Kidney Injury Network (AKIN) criteria. The secondary outcomes included serum cystatin C and estimated glomerular filtration rate on postoperative days 1, 2, and 7, and in-hospital need for renal replacement therapy (RRT). Long-term outcomes included RRT and all-cause mortality.

MAIN RESULTS

Ninety-eight patients completed the study (dexmedetomidine, n = 48; control, n = 50). AKIN stage 1 AKI occurred in 3/48 (6.3%) patients receiving dexmedetomidine, compared with 11/50 (22%) patients receiving normal saline (odds ratio = 0.24, 95% CI: 0.07 to 0.89, P = 0.041). This difference remained significant after adjusting for baseline covariates (adjusted odds ratio = 0.21, 95% CI: 0.05 to 0.84; P = 0.028). Dexmedetomidine led to a lower serum cystatin C on postoperative day 1 (median [IQR] mg/L: 1.31 [1.02-1.72] vs. 1.58 [1.28-1.96]). There were no between-group differences in other secondary or long-term outcomes. During the follow-up (median = 28.4 months), 1 patient in the dexmedetomidine group and 3 patients in the control group required RRT.

CONCLUSIONS

Dexmedetomidine reduced the incidence of AKI in TBAD patients after EVAR procedures. The long-term benefits of dexmedetomidine in this patient population warrant further investigation.

TRIAL REGISTRATION

ChiCTR-IPR-15006372.

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.

Contrast-induced nephropathy in non-cardiac vascular procedures, a narrative review: Part 1

Contrast-induced nephropathy (CIN) is an important complication of iodinated contrast medium (CM) administration, which is associated with both short- and long-term adverse outcomes (e.g., cardiorenal events, longer hospital stay, and mortality). CIN has been mainly studied in relation to cardiac procedures, but it can also occur following non-cardiac vascular interventions. This is Part 1 of a narrative review summarizing the available literature on CIN after non-cardiac vascular diagnostic or therapeutic procedures for aortic aneurysm and carotid stenosis. We discuss the definition, pathophysiology, incidence, risk factors, biomarkers, and consequences of CIN in these settings, as well as preventive strategies and alternatives to limit iodinated CM use. Physicians and vascular surgeons should be aware of CM-related adverse events and the potential strategies to avoid them. Clearly, more research in this important field is required.

Current issues on simultaneous TAVR (Transcatheter Aortic Valve Replacement) and EVAR (Endovascular Aneurysm Repair)

Simultaneous EVAR and TAVR is technically feasible and is a reliable option in high-risk patients.

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.

Assessment of Kidney Function After Transcatheter Aortic Valve Replacement

Background:

Transcatheter aortic valve replacement (TAVR), although associated with an increased risk for acute kidney injury (AKI), may also result in improvement in renal function.

Objective:

The aim of this study is to evaluate the magnitude of kidney function improvement (KFI) after TAVR and to assess its significance on long-term mortality.

Design:

This is a prospective single center study.

Setting:

The study was conducted in cardiology department, interventional unit, in a tertiary hospital.

Patients:

The cohort included 1321 patients who underwent TAVR.

Measurements:

Serum creatinine level was measured at baseline, before the procedure, and over the next 7 days or until discharge.

Methods:

Kidney function improvement was defined as the mirror image of AKI, a reduction in pre-procedural to post-procedural minimal creatinine of more than 0.3 mg/dL, or a ratio of post-procedural minimal creatinine to pre-procedural creatinine of less than 0.66, up to 7 days after the procedure. Patients were categorized and compared for clinical endpoints according to post-procedural renal function change into 3 groups: KFI, AKI, or preserved kidney function (PKF). The primary endpoint was long-term all-cause mortality.

Results:

The incidence of KFI was 5%. In 55 out of 66 patients patients, the improvement in kidney function was minor and of unclear clinical significance. Acute kidney injury occurred in 19.1%. Estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m² was a predictor of KFI after multivariable analysis (odds ratio = 0.93 to develop KFI; confidence interval [95% CI]: 0.91-0.95, P < .001). Patients in the KFI group had a higher Society of Thoracic Surgery (STS) score than other groups. Mortality rate did not differ between KFI group and PKF group (43.9% in KFI group and 33.8% in PKF group) but was significantly higher in the AKI group (60.7%, P < .001).

Limitations:

The following are the limitations: heterozygous definitions of KFI within different studies and a single center study. Although data were collected prospectively, analysis plan was defined after data collection.

Conclusions:

Improvement in kidney function following TAVR was not a common phenomenon in our cohort and did not reduce overall mortality rate.

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.

RenalGuard system and conventional hydration for preventing contrast-associated acute kidney injury in patients undergoing cardiac interventional procedures: A systematic review and meta-analysis

BACKGROUND

Contrast-associated acute kidney injury (CA-AKI) can increase the mortality of patients undergoing transcatheter aortic valve replacement (TAVR) or percutaneous coronary intervention (PCI). The purpose of this paper was to compare the efficacy of the RenalGuard System and conventional hydration regimen in preventing CA-AKI in patients with TAVR or PCI.

METHODS

We searched PubMed, Embase, Web of Science, and the Cochrane Central Register of Clinical Trials (last updated July 11, 2020) for suitable reports. The primary outcome was the occurrence of CA-AKI. The secondary outcomes were renal replacement therapy (RRT), major cardiovascular events (MACEs), and other adverse complications.

RESULTS

The search strategy yielded 270 studies (with data for 2067 participants). In the subgroup of PCI, low incidence of CA-AKI (6.7% vs 15.7%; 95%CI: 0.27 to 0.54; I² = 8%; P < 0.00001) associate with RenalGuard group (RG) rather than control group (CG). Similarly, in the subgroup of TAVR, a low incidence of CA-AKI (15.6% vs 26.9%; 95%CI: 0.35 to 0.82; I² = 88%; P = 0.004) relates to RG. However, this result is highly heterogeneous. Compare with conventional hydration, RenalGuard significantly reduce the incidence of pulmonary edema (1.5%vs4.1%; 95%CI: 0.18 to 0.72; I² = 0%; P = 0.004).

CONCLUSIONS

RenalGuard System can lessen the risk of CA-AKI and RRT in patients undergoing PCI. But for patients experiencing TAVR, due to unique hemodynamic effects, the role of RenalGuard remains questionable. RenalGuard is more secure than conventional hydration. Future work should elucidate the feasibility and safety of this prophylactic intervention in cardiac interventional therapy.

General anesthesia vs. sedation in transcatheter aortic valve implantation (TAVI): retrospective study of the incidence of acute kidney injury

INTRODUCTION AND OBJECTIVES

Anesthetic techniques have been reported as having an impact on acute kidney injury (AKI) incidence in the postoperative period in patients undergoing transcatheter aortic valve implantation (TAVI). This study aimed to assess whether exists an association between anesthetic approach in patients undergoing TAVI and the post-operative AKI incidence. The existence of association between anesthetic approach and mortality was also assessed.

MATERIALS AND METHODS

A retrospective, single-center, observational study was conducted at the Centro Hospitalar Universitário de São João, a Portuguese reference center. All patients undergoing TAVI from January 2015 to June 2018 were recruited and were divided into two groups for analysis: general anesthesia (GA) and sedation.

RESULTS

One hundred and seven patients underwent TAVI (GA: n = 24; sedation: n = 83) and the overall incidence of AKI was 14.02%. We found a higher incidence of intraoperative hypotension in the GA group (83.3 vs. 33.7%, p < 0.001). Regarding postoperative outcomes, there were no significant differences in AKI incidence (20.8 vs. 12.0%, p = 0.319) and mortality. A significant association was found between postoperative AKI and preexisting chronic kidney disease (CKD), preoperative heart failure functional class, intraoperative hypotension, longer length of stay in level II unit, longer hospital stay and worsening of previous CKD stage.

CONCLUSIONS

It was not possible to established association between the anesthetic approach for TAVI procedures and postoperative AKI and mortality. Our study reinforces the importance of preventing AKI incidence, considering its impact on the worsening of baseline CKD and on the length of stay, leading to higher hospitalization costs.

Acute kidney injury after transcatheter aortic valve implantation and mortality risk-long-term follow-up

BACKGROUND

Acute kidney injury (AKI) complicating transcatheter aortic valve implantation (TAVI) is relatively frequent and associated with significant morbidity. Previous studies have shown a higher 30-day and 1-year mortality risk in patients with periprocedural AKI. Our aim was to identify the prognostic impact of periprocedural AKI on long-term follow-up.

METHODS

This is a single-center prospective study evaluating patients undergoing TAVI for severe aortic stenosis. AKI was defined according to the Valve Academic Research Consortium 2 definition, as an absolute increase in serum creatinine ≥0.3 mg/dL or an increase >50% within the first week following TAVI. Mortality data were compared between patients who developed AKI and those who did not. Logistic and Cox regressions were used for survival analysis.

RESULTS

The final analysis included 1086 consecutive TAVI patients. AKI occurred in 201 patients (18.5%). During the follow-up period, 289 patients died. AKI was associated with an increased risk of 30-day mortality {4.5 versus 1.9% in the non-AKI group; hazard ratio [HR] 3.70 [95% confidence interval (CI) 1.35-10.13]}. Although 1-year mortality was higher in the AKI group in univariate analysis, it was not significant after a multivariate regression. AKI was a strong predictor of longer-term mortality [42.3 versus 22.7% for 7-year mortality; HR 1.71 (95% CI 1.30-2.25)]. In 189 of 201 patients we had data regarding recovery from AKI up to 30 days after discharge. In patients with recovery from AKI, the mortality rate was lower (38.2 versus 56.6% in the nonrecovery group; P = 0.022).

CONCLUSIONS

Periprocedural AKI following TAVI is a strong risk factor for short-term as well as long-term mortality (up to 7 years). Therefore more effort is needed to reduce this complication.

Contrast-Induced Acute Kidney Injury-Definitions, Epidemiology, and Implications

Contrast-induced acute kidney injury (CI-AKI) is the acute onset of renal injury following exposure to iodinated contrast media. Several definitions have been used, which complicates the estimation of the epidemiological relevance of this condition and comparisons in outcome research. The incidence of CI-AKI increases as a function of patient and procedure complexity in coronary, endovascular, and structural interventions. CI-AKI is associated with a high burden of short- and long-term adverse events, and leads to increased healthcare costs. This review will provide an overview of the definitions, epidemiology, and implications of CI-AKI in patients undergoing coronary, endovascular, and structural catheter-based procedures.

Non-contrast MRI protocol for TAVI guidance: quiescent-interval single-shot angiography in comparison with contrast-enhanced CT

Objectives

To prospectively compare unenhanced quiescent-interval single-shot MR angiography (QISS-MRA) with contrast-enhanced computed tomography angiography (CTA) for contrast-free guidance in transcatheter aortic valve intervention (TAVI).

Methods

Twenty-six patients (mean age 83 ± 5 years, 15 female [58%]) referred for TAVI evaluation underwent QISS-MRA for aortoiliofemoral access guidance and non-contrast three-dimensional (3D) “whole heart” MRI for prosthesis sizing on a 1.5-T system. Contrast-enhanced CTA was performed as imaging gold standard for TAVI planning. Image quality was assessed by a 4-point Likert scale; continuous MRA and CTA measurements were compared with regression and Bland-Altman analyses.

Results

QISS-MRA and CTA-based measurements of aortoiliofemoral vessel diameters correlated moderately to very strong (r = 0.572 to 0.851, all p ≤ 0.002) with good to excellent inter-observer reliability (intra-class correlation coefficient (ICC) = 0.862 to 0.999, all p < 0.0001) regarding QISS assessment. Mean diameters of the infrarenal aorta and iliofemoral vessels differed significantly (bias 0.37 to 0.98 mm, p = 0.041 to < 0.0001) between the two modalities. However, inter-method decision for transfemoral access route was comparable (κ = 0.866, p < 0.0001). Aortic root parameters assessed by 3D whole heart MRI strongly correlated (r = 0.679 to 0.887, all p ≤ 0.0001) to CTA measurements.

Conclusion

QISS-MRA provides contrast-free access route evaluation in TAVI patients with moderate to strong correlations compared with CTA and substantial inter-observer agreement. Despite some significant differences in minimal vessel diameters, inter-method agreement for transfemoral accessibility is strong. Combination with 3D whole heart MRI facilitates unenhanced TAVI guidance.

Key Points

• QISS-MRA and CTA inter-method agreement for transfemoral approach is strong.

• QISS-MRA is a very good alternative to CTA and MRA especially in patients with Kidney Disease Outcomes Quality Initiativestages 4 and 5.

• Combination of QISS-MRA and 3D “whole heart” MRI facilitates fully unenhanced TAVI guidance.

Kidney autotransplantation for the treatment of renal artery occlusion after endovascular aortic repair: a case report

BACKGROUND

Unintentional renal artery occlusion after endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm remains one of the most unfavorable complications. Renal salvage options include percutaneous transluminal renal artery angioplasty (PTRA) and open hepatosplenorenal bypass. However, the usefulness of kidney autotransplantation (AutoTx) remains unclear.

CASE PRESENTATION

A 76-year-old woman with a right solitary kidney attributable to a left renal thromboembolism had previously undergone EVAR with a stent graft for an infrarenal aortic aneurysm, which led to ostial occlusion of the right renal artery. In addition, she had undergone PTRA and stenting. Two days before admission, she developed leg edema and hypertension, leading her to visit the hospital. Her serum creatinine level was 2.4 (baseline, 1.0) mg/dL. Acute kidney injury due to renal artery in-stent restenosis was suspected; re-angioplasty was attempted on day 2 of hospitalization, but was unsuccessful. Her renal function did not improve and anuria persisted; thus, hemodialysis was initiated on the same day. The right kidney size (8.6 cm) was preserved relative to her body size, with only mild cortical atrophy. Doppler ultrasonography and mercaptoacetyltriglycine scintigraphy revealed minimal but significant perfusion of the right kidney. Therefore, we considered that kidney perfusion was sustained and renal function could be reversed. On day 25 of hospitalization, right kidney AutoTx to the right iliac fossa was performed to reestablish adequate renal perfusion and reverse the need for dialysis. Soon after the procedure, the patient started passing urine. Her renal function improved; her serum creatinine level decreased to 1.0 mg/dL on day 33 of hospitalization. Hemodialysis was discontinued after the surgery. Zero-hour kidney biopsy showed only mild tubular injury, with neither tubular necrosis nor glomerular abnormalities.

CONCLUSIONS

Kidney AutoTx can be performed for patients with renal artery in-stent occlusion after unsuccessful PTRA who previously underwent EVAR. Our case showed successful recovery of renal function nearly 1 month after renal artery occlusion, indicating that revascularization should be considered even if it is delayed, as the kidney might be perfused through collateral circulation.

Outcomes of Evolut R Versus CoreValve After Transcatheter Aortic Valve Implantation: A Meta-Analysis

BACKGROUND

Superiority of the new-generation, self-expanding Evolut R compared with the first-generation CoreValve on outcomes after transcatheter aortic valve implantation (TAVI) is unclear. This meta-analysis sought to investigate the outcomes of Evolut R vs CoreValve after TAVI.

METHODS

A systematic review of studies comparing outcomes of Evolut R and CoreValve after TAVI was performed through PubMed, EMBASE and Cochrane Library. Crude risk ratios (RRs) were calculated with 95% confidence intervals using a random effects model. Outcomes of interest were mortality, myocardial infarction (MI), stroke or transient ischaemic attack (TIA), severe bleeding, acute kidney injury (AKI), major vascular complications (MVC), permanent pacemaker implantation (PPI), moderate or severe paravalvular regurgitation (PVR), and device failure.

RESULTS

Six studies involving 11,530 patients (4,597 receiving Evolut R and 6,933 receiving CoreValve) were included. There was no significant difference in 30-day all-cause mortality between Evolut R and CoreValve (3.4% vs 5.0%, p = 0.10). The incidence of MI (0.2% vs 0.5%, p = 0.02), AKI (6.0% vs 9.2%, p = 0.001), moderate or severe PVR (6.4% vs 8.0%, p = 0.04), and device failure (3.5% vs 5.2%, p = 0.04) were significantly lower in Evolut R than CoreValve. There were trends toward less severe bleeding (7.2% vs 8.8%, p = 0.05) and PPI (18.6% vs 20.8%, p = 0.05) in Evolut R. The rates of stroke or TIA and MVC were similar between the two prostheses.

CONCLUSIONS

Compared with CoreValve, Evolut R did not reduce 30-day all-cause mortality, but significantly improved periprocedural complications after TAVI.

Stratification and Risk Reduction of Perioperative Acute Kidney Injury: An Update

Perioperative acute kidney injury is associated with morbidity and mortality. Several definitions have been proposed, incorporating small changes of serum creatinine and urinary output reduction as diagnostic criteria. In the surgical patient, comorbidities, type and timing of surgery, and nephrotoxins are important. Patient comorbidities remain a significant risk factor. Urgent or emergent surgery and cardiac or transplantation procedures are associated with a higher risk of acute kidney injury. Nephrotoxic drugs, contrast dye, and diuretics worsen preexisting kidney dysfunction or act as an adjunctive insult to perioperative injury. This review includes preoperative, intraoperative, and postoperative issues that can be mitigated.

Simultaneous thoracic aortic endovascular graft and transfemoral transcatheter aortic valve replacement in a patient with a descending aortic thrombus

Severe descending thoracic and abdominal aortic pathology can deter consideration of transfemoral (TF) access for transcatheter aortic valve replacement (TAVR) in adults with severe symptomatic aortic stenosis (AS) and may lead to utilization of alternative access sites. We report a case of an 88-year-old frail woman with severe symptomatic AS referred for TAVR with demonstration of a large thrombus in the descending thoracic aorta immediately distal to the left subclavian artery. Given concerns of thrombus embolization with femoral advancement of the transcatheter valve, coverage with a thoracic aortic endograft was planned immediately prior to the TAVR.

Acute kidney injury post-transcatheter aortic valve replacement

Transcatheter aortic valve replacement (TAVR) is a treatment option in high-risk patients with severe aortic stenosis who are not surgical candidates. In light of emerging evidence, it is being increasingly performed even in intermediate-risk patients in recent years. Patients who develop acute kidney injury (AKI) following TAVR are known to have worse outcomes. The objective of this concise review was to identify the prevalence and the impact of AKI following TAVR on patient outcomes by including the most recent literature in our search. After a thorough search on MEDLINE, Google Scholar, and PubMed, we included all literature relevant to AKI following TAVR. We found that AKI was caused by a variety of reasons, such as hemodynamic instability during rapid pacing, blood transfusion, periprocedural embolization, and use of contrast medium, to name a few. In patients who developed AKI following TAVR, 30-day and 1-year mortality were increased. Further, in these patients, length and cost of hospital stay were increased as well. Preventive measures such as optimal periprocedural hydration, careful contrast use, and techniques to prevent embolization during device implantation have been tried with limited success. Given that TAVR is expected to be increasingly performed, this review aimed to summarize the rapidly expanding currently available literature in an effort to reduce procedural complications and thereby improve patient outcomes.

Determinants of Acute Kidney Injury and Renal Function Decline After Endovascular Abdominal Aortic Aneurysm Repair

OBJECTIVE/BACKGROUND

Endovascular aneurysm repair (EVAR) may be associated with renal injury and more insight is needed into potential risk factors. The aim was to identify clinical, anatomical, and peri-procedural parameters as potential risk factors for the occurrence of acute kidney injury (AKI) and to evaluate chronic kidney disease (CKD) after EVAR.

METHODS

A cohort of 212 consecutive patients who underwent elective EVAR for abdominal aortic aneurysm from January 2009 to October 2016 was included. A subgroup of 149 patients with 2 years follow-up was compared with a set of 135 non-operated aneurysm patients with smaller aneurysms (similar cardiovascular risk profile) to assess CKD. Primary outcomes were AKI (Acute Kidney Injury Network criteria) and CKD measured by estimated glomerular filtration rate (Kidney Disease Improving Global Outcomes guidelines). For AKI, candidate risk factors were identified by univariate and multivariate logistic regression analysis; for chronic renal function decline, risk factors were identified using Cox regression analysis.

RESULTS

AKI occurred in 30 patients (15%). On multivariate analysis, the use of angiotensin II blocker (odds ratio [OR] 4.08, 95% confidence interval [CI] 1.38-12.07) and peri-operative complications (OR 3.12, 95% CI 1.20-8.10) were independent risk factors for AKI, whereas statin use was a protective factor (OR 0.19, 95% CI 0.07-0.52). EVAR resulted in a significant increase (23.5%) in the occurrence of CKD compared with the control group (6.7%; p <.001). On univariate and multivariate Cox regression the risk factors: aortic neck diameter (per mm increase) (hazard ratio [HR] 1.13, 95% CI 1.02-1.25), renal artery stenosis >50% (HR 2.24, 95% CI 1.05-4.79), and the occurrence of AKI (HR 2.19, 95% CI 0.99-4.85) were significant predictors of CKD.

CONCLUSION

This study identified use of angiotensin II blockers and peri-operative complications as risk factors for AKI. In addition, the problem of renal function decline after EVAR is highlighted, which indicates that prolonged protective measures (e.g., in those patients at high risk) over time are needed to improve patient outcomes.