Predictors of Acute Kidney Injury Following Elective Open and Endovascular Aortic Repair for Abdominal Aortic Aneurysm

Factors predicting acute kidney injury in patients after abdominal aortic aneurysm repair

INTRODUCTION

Postoperative acute kidney injury (AKI) is one of the most frequent complications in abdominal aortic aneurysm (AAA) patients after open and endovascular aortic aneurysm repair. AKI decreases the efficiency of kidney function, allowing accumulation of waste products in the body, and an imbalance of water, acid and electrolytes in the body. As a result, the functioning of various organs throughout the body is affected. These effects may raise the cost of treatment, length of stay, and mortality rate.

OBJECTIVE

This study aims to examine the predictive factors of AKI - preoperative of estimated glomerular filtration rate (eGFR), preoperative of hemoglobin level, types of abdominal aortic aneurysms repair, and intraoperative of cardiac arrhythmias - after open and endovascular aortic repair among AAA patients within 72 h.

METHODS

This is a retrospective study of 196 patients with AAA after elective open and endovascular aortic aneurysm repair within the first 72 h who met the inclusion criteria recruited from a tertiary care hospital in Bangkok, Thailand. Postoperative AKI after elective open and endovascular aortic repair among AAA patients is defined by the 2012 Kidney Disease Improving Global Outcomes (KDIGO) Clinical Practice Guidelines.

RESULTS

A total of 196 AAA patients, 75.5% were male with an average age of 75.12 years (SD = 8.45). Endovascular aortic aneurysm repair was used more frequently than open aortic aneurysm repair (64.8% vs 35.2%) and 37.2% of the AAA patients had intraoperative cardiac arrhythmias. The occurrence of AKI among the AAA patients after abdominal aortic aneurysm repair within 72 h was 54.1%. The AKI rate of EVAR patients was 69.8% while the AKI rate for OAR patients was 30.2%. The preoperative estimated glomerular filtration rate (eGFR) and hemoglobin level were found to jointly predict AKI and explain 32.2% of the variance (Nagelkerke R2 = 0.322, p < .05). However, the type of abdominal aortic aneurysms repair and intraoperative cardiac arrhythmias did not correlate with the incidence of AKI in AAA repair patients. The predictive factors for AKI among AAA patients after aortic aneurysm repair were preoperative eGFR < 60 mL/min/1.73 m2 (OR = 4.436, 95% CI: 2.202-8.928, p < .001) and preoperative hemoglobin level between 8.1-10.0 g/dL (OR = 4.496, 95% CI: 1.831-11.040, p = .001).

CONCLUSION

Preoperative eGFR < 60 mL/min/1.73 m2 and preoperative hemoglobin level between 8.1-10.0 g/dL were the predictive factors for AKI among AAA patients after both open and endovascular AAA repair. Therefore, healthcare providers should be aware of and monitor signs of AKI after surgery in AAA patients, especially those undergoing EVAR with lower eGFR and hemoglobin levels.

Preoperative Anemia Is Associated With Postoperative Renal Failure After Elective Open Aortic Repair

INTRODUCTION

Preoperative anemia has been consistently shown to be a risk factor for acute kidney injury (AKI) after cardiac surgery. However, this association has not been examined in the open abdominal aortic aneurysm repair (OAR) population and is the subject of this analysis.

METHODS

Targeted Vascular Module from the American College of Surgeons National Surgical Quality Improvement Program was queried for patients undergoing OAR from 2013 to 2019. Anemia was defined according to World Health Organization Guidelines: Hematocrit<36% for women or <39% for men. Primary endpoint was 30-day AKI. Anemia's effect on AKI was determined using inverse probability weighted logistic regression.

RESULTS

There were 2275 OAR; mean age was 70.9 ± 8.2 y; 24.0% were women. Anemia was present in 498 (26.3%) patients; 165 (7.6%) had a hematocrit<33% and 8 (0.35%) had a hematocrit<24%. Differences in patient factor were nonsignificant after weighting. Any degree of postoperative AKI was more common in the anemia group (11.2% vs 5.1%; unweighted P < 0.001), as was AKI requiring hemodialysis (7.7% vs 3.2%; unweighted P < 0.001). In the weighted multivariable analysis, anemia was independently associated with postoperative AKI (odds ratio 1.51; 95% confidence interval: 1.01-2.26; P = 0.042) while controlling for age and operative factors. Patients with postoperative AKI were significantly more likely to die postoperatively than those without (26.1% vs 1.9%; <0.001).

CONCLUSIONS

Preoperative anemia was independently associated with post-OAR AKI after propensity weighting and controlling for operative factors. AKI is a major source of morbidity and mortality in these patients, and, if time permits, preoperative correction of anemia or its underlying cause should be considered in high-risk patients.

The impact of obesity on perioperative and postoperative outcomes after elective endovascular abdominal aortic aneurysm repair

BACKGROUND

Obesity is a common and growing health problem in vascular surgery patients, as it is in all patient groups. Evidence regarding body mass index (BMI) on endovascular aneurysm repair (EVAR) outcomes is not clear in the literature. We aimed to determine the impact of obesity on perioperative and midterm outcomes of elective EVAR between obese and non-obese patients.

METHODS

Under a retrospective study design, a total of 120 patients (109 males, 11 females, mean age: 74.45 ± 8.59 (53-92 years)) undergoing elective EVAR between June 2012 and May 2020 were reviewed. Patients were stratified into two groups: obese (defined as a body mass index (BMI) ≥ 30 kg/m²) and non-obese (mean BMI < 30 kg/m² (32.25 ± 1.07 kg/m² vs 25.85 ± 2.69 kg/m²)).

RESULTS

Of the 120 patients included in the study, 81 (67.5%) were defined as "nonobese," while 39 (32.5%) were obese. The mean BMI of the study group was 27.93 ± 3.78 kg/m². In obese patients, the procedure time, fluoroscopy time, and dose area product (DAP) values were longer than those of non-obese patients: 89.74 ± 20.54 vs 79.69 ± 28.77 min (p = 0.035), 33.23 ± 10.14 vs 38.17 ± 8.61 min (p = 0.01) and 133.69 ± 58.17 vs 232.56 ± 51.87 Gy.cm² (p < 0.001). Although there was no difference in sac shrinkage at 12-month follow-up, there was a significant decrease at 6-month follow-up in both groups (p = 0.017). Endoleak occurred in 17.9% (n = 7) of the obese group versus 11.1% (n = 9) of the non-obese group (p = 0.302). Iliac branch occlusion developed in four patients, 3 (3.7%) in the non-obese group and 1 (2.6%) in the obese group (p = 0.608). The all-cause mortality rate was slightly higher in the obese group; however, it did not differ between the groups (p = 0.463).

CONCLUSION

In addition to the longer procedure times, fluoroscopy times, and DAP values in obese patients, regardless of obesity, significant sac shrinkage in the first 6 months of follow-up was observed in both groups. No difference was documented with regards to mortality or morbidity following EVAR.

A simplified acute kidney injury predictor following endovascular aortic repair: ACEF score

OBJECTIVES

Treatment of abdominal aortic aneurysms (AAA) with endovascular aortic repair (EVAR) has become quite common in recent years. This method, which has many advantages compared to the open surgical procedure, also has some complications. One of these complications is acute kidney injury (AKI). ACEF (age, creatinine, and ejection fraction) score, which is gaining popularity, can be an easy-to-use and cost-effective method in detecting this condition that causes increased morbidity and mortality. We aimed to evaluate whether this ACEF score may predict a development of AKI in patients who underwent EVAR.

METHODS

A total of 133 consecutive patients with AAA who underwent EVAR were analyzed. The primary endpoint of the study was the development of AKI. The best cut-off value for the ACEF score to predict the development of AKI was calculated and according to this value, the patients were divided into two groups as those with high ACEF scores and those with low ACEF scores. ACEF score was calculated by the formula of age/EF + 1 (if baseline creatinine > 2 mg/dL).

RESULTS

After the exclusion criteria, a total of 118 patients were included in the study, and 20 (16.9%) of them developed AKI after EVAR. In the ROC curve analysis, a cut-off value of 1.34 was found for the ACEF score, and scores above this value were found to be independent predictors of AKI development after EVAR. In addition to the ACEF score, the contrast media volume was also found to be an independent predictor of the development of AKI.

CONCLUSION

In conclusion, ACEF is a simple and effective scoring system in patients undergoing EVAR. To the best our knowledge, our study is the first study which applies ACEF score to predict AKI in EVAR patients.

Perioperative care in open aortic vascular surgery: A Consensus Statement by the Enhanced Recovery after Surgery (ERAS®) Society and Society for Vascular Surgery

The Society for Vascular Surgery and the Enhanced Recovery After Surgery (ERAS®) Society formally collaborated and elected an international, multi-disciplinary panel of experts to review the literature and provide evidence-based recommendations related to all of the health care received in the perioperative period for patients undergoing open abdominal aortic operations (both transabdominal and retroperitoneal approaches, including supraceliac, suprarenal, and infrarenal clamp sites, for aortic aneurysm and aortoiliac occlusive disease). Structured around the ERAS® core elements, 36 recommendations were made and organized into preadmission, preoperative, intraoperative, and postoperative recommendations.

Impact of Sarcopenia on Acute Kidney Injury after Infrarenal Abdominal Aortic Aneurysm Surgery: A Propensity Matching Analysis

Background: Sarcopenia contributes to increased morbidity and mortality in patients undergoing surgery for abdominal aortic aneurysms (AAA). However, few reports have demonstrated whether sarcopenia would affect the development of postoperative acute kidney injury (AKI) in these patients. This study aimed to examine whether sarcopenia is associated with AKI and morbidity and mortality after infrarenal AAA operation. Methods: We retrospectively analysed 379 patients who underwent infrarenal AAA surgery. The diagnosis of sarcopenia was performed using the skeletal muscle index, which was calculated from axial computed tomography at the level of L3. The patients were separated into those with sarcopenia (n = 104) and those without sarcopenia (n = 275). We applied multivariable and Cox regression analyses to evaluate the risk factors for AKI and overall mortality. A propensity score matching (PSM) evaluation was done to assess the postoperative results. Results: The incidence of AKI was greater in sarcopenia than non-sarcopenia group before (34.6% vs. 15.3%; p < 0.001) and after the PSM analysis (34.6% vs. 15.4%; p = 0.002). Multivariable analysis revealed sarcopenia to be associated with AKI before (p = 0.010) and after PSM (p = 0.016). Sarcopenia was also associated with overall mortality before (p = 0.048) and after PSM (p = 0.032). A Kaplan–Meier analysis revealed that overall mortality was elevated patients with sarcopenia before and after PSM than in those without (log-rank test, p < 0.001, p = 0.022). Conclusions: Sarcopenia was associated with increased postoperative AKI incidence and overall mortality among individuals who underwent infrarenal AAA operation.

Renal function-adjusted contrast medium volume is a major risk factor in the occurrence of acute kidney injury after endovascular aneurysm repair

Acute kidney injury (AKI) is a complication that can occur during endovascular aneurysm repair (EVAR), increasing postoperative mortality and disease-related death. We therefore evaluated the incidence of AKI after elective EVAR, as well as related factors affecting AKI occurrence, investigating the volume of contrast medium (CV)/estimated glomerular filtration rate (eGFR) ratio as a predictive factor.We retrospectively reviewed the data of patients who underwent EVAR for infrarenal abdominal aorta aneurysm at a single center between April 2011 and December 2018. AKI was defined according to the Kidney Disease: Improving Global Outcomes criteria. We evaluated the occurrence of AKI within the first 7 days postoperatively, comparing serum creatinine levels, eGFR, CV, CV/eGFR ratio, fluid input and output, and morbidity between the AKI and no-AKI groups.The data of 147 patients were analyzed, of which 131 (89.1%) were males (mean age: 72.10±7.40 years); the incidence of AKI was 4.1% (6/147 patients). The mean dose of contrast agents used was greater in the AKI group than in the no-AKI group (249.17 ± 83.21 mL vs 179.43 ± 84.32 mL, respectively; P = .05). The baseline eGFR was 42.69 ± 22.08 mL/kg/1.73 m2 in the AKI group and 77.96 ± 18.92 mL/kg/1.73 m2 in the no-AKI group (P = .001). The CV/eGFR ratio was significantly higher in the AKI group (8.21 ± 6.13 vs 2.46 ± 1.44; P = 0.003). Baseline eGFR (odds ratio [OR] = 0.922, P = .001) and the CV/eGFR ratio (OR = 2.049, P = .008) were observed to be factors related to the occurrence of AKI in the logistic regression analysis for patients' characteristics, operation-related factors, and renal outcomes. In the receiver operating characteristic curve analysis, the area under the curve of the CV/eGFR ratio was 0.856, indicating the greatest influence. A CV/eGFR ratio cutoff value of 3.84 was considered the most appropriate, with an 83.3% sensitivity and 83.0% specificity.The CV/eGFR ratio, rather than the absolute amount of contrast agents, was associated with the development of AKI after EVAR. The CV/eGFR ratio could be used as a possible indicator to limit the amount of contrast media required for the procedure.

Beta-Trace Protein as a Potential Marker of Acute Kidney Injury: A Pilot Study

INTRODUCTION

Acute kidney injury (AKI) is a frequent complication among patients in the intensive care unit (ICU). The limitations of serum Cr (sCr) in timely detecting AKI are well known. Beta-trace protein (BTP) is emerging as a novel endogenous glomerular filtration rate marker. The aim of this study was to explore the role of BTP as a marker of AKI.

METHODS

Patients admitted to the ICU undergoing surgery were included. BTP, sCr, Cystatin C (CysC), and neutrophil gelatinase-associated lipocalin (NGAL) were measured preoperatively, postoperatively (post-op), and at the first (D1) and second (D2) post-op day. AKI was defined as an increase of sCr to ≥1.5-fold from baseline within 2 days after surgery.

RESULTS

Of the 52 patients studied, 10 patients (19%) developed AKI. Patients with AKI were older (69.6 ± 10.7 vs. 58.1 ± 16.7 years, p = 0.043) and had a longer length of ICU stay (13 [IQR 6-49] vs. 6 [IQR 5-8] days, p = 0.032). Between the 2 groups, the evolution of BTP, sCr, CysC, and NGAL over time differed significantly, with overall higher values in the AKI group. ROC analysis for the detection of AKI within 2 days after surgery showed a great accuracy for BTP. The area under the curve (AUC) for BTP post-op; D1; and D2 was, respectively, 0.869 ± 0.049; 0.938 ± 0.035; and 0.943 ± 0.032. The discriminative power of a BTP measurement on D1 was superior in detecting AKI compared to NGAL (adjusted p value = 0.027). We could not detect a significant difference between the AUCs of other biomarkers (NGAL, sCr, and CysC).

CONCLUSION

Serum BTP is a promising marker for diagnosing AKI in ICU patients undergoing surgery.

Perioperative Renoprotection: General Mechanisms and Treatment Approaches

In the perioperative setting, acute kidney injury (AKI) is a frequent complication, and AKI itself is associated with adverse outcomes such as higher risk of chronic kidney disease and mortality. Various risk factors are associated with perioperative AKI, and identifying them is crucial to early interventions addressing modifiable risk and increasing monitoring for nonmodifiable risk. Different mechanisms are involved in the development of postoperative AKI, frequently picturing a multifactorial etiology. For these reasons, no single renoprotective strategy will be effective for all surgical patients, and efforts have been attempted to prevent kidney injury in different ways. Some renoprotective strategies and treatments have proven to be useful, some are no longer recommended because they are ineffective or even harmful, and some strategies are still under investigation to identify the best timing, setting, and patients for whom they could be beneficial. With this review, we aim to provide an overview of recent findings from studies examining epidemiology, risk factors, and mechanisms of perioperative AKI, as well as different renoprotective strategies and treatments presented in the literature.

Predicting Acute Kidney Injury after Cardiac Surgery by Machine Learning Approaches

Cardiac surgery-associated AKI (CSA-AKI) is common after cardiac surgery and has an adverse impact on short- and long-term mortality. Early identification of patients at high risk of CSA-AKI by applying risk prediction models allows clinicians to closely monitor these patients and initiate effective preventive and therapeutic approaches to lessen the incidence of AKI. Several risk prediction models and risk assessment scores have been developed for CSA-AKI. However, the definition of AKI and the variables utilized in these risk scores differ, making general utility complex. Recently, the utility of artificial intelligence coupled with machine learning, has generated much interest and many studies in clinical medicine, including CSA-AKI. In this article, we discussed the evolution of models established by machine learning approaches to predict CSA-AKI.

Renal Dysfunction After Liver Transplantation: Effect of Donor Type

Recipients of donation after circulatory death (DCD) grafts are reportedly at higher risk of developing renal dysfunction after liver transplantation (LT). We compared the development of acute kidney injury (AKI) and chronic kidney disease (CKD) after LT in recipients of DCD versus donation after brain death (DBD) or living donor liver transplantation (LDLT) livers. Adult recipients of DBD, LDLT, and DCD between 2012 and 2016 at Toronto General Hospital were included. AKI was defined as a post-LT increase of serum creatinine (sCr) ≥26.5 µmol/L within 48 hours or a ≥50% increase from baseline, and CKD was defined as an estimated glomerular filtration rate <60 mL/minute for >3 months. A total of 681 patients (DCD, n = 57; DBD, n = 446; and LDLT, n = 178) with similar baseline comorbidities were included. Perioperative AKI (within the first 7 postoperative days) was observed more frequently in the DCD group (61%; DBD, 40%; and LDLT, 44%; P = 0.01) and was associated with significantly higher peak AST levels (P < 0.001). Additionally, patients in the DCD group had a significantly higher peak sCr (P < 0.001) and a trend toward higher rates of AKI stage 3 (DCD, 33%; DBD, 21%; LDLT, 21%; P = 0.11). The proportions of recovery from AKI (DCD, 77%; DBD, 72%; LDLT, 78%; P = 0.45) and patients developing CKD (DCD, 33%; DBD, 32%; LDLT, 32%; P = 0.99) were similar. Nevertheless, patients who received DCD or DBD LT and required perioperative renal replacement therapy showed significantly lower patient survival in multivariate analysis (hazard ratio, 7.90; 95% confidence interval, 4.51-13.83; P < 0.001). In conclusion, recipients of DCD liver grafts experience higher rates of short-term post-LT renal dysfunction compared with DBD or LDLT. Additional risk factors for the development of severe kidney injury, such as high Model for End-Stage Liver Disease score, massive transfusions, or donor age ≥60 years should be avoided.

Etiology and impact on outcomes of polycystic kidney disease in abdominal aortic aneurysm

PURPOSE

We investigated the etiology and impact on outcomes of polycystic kidney disease in patients with abdominal aortic aneurysm.

METHODS

Eight-hundred patients who underwent open (n = 603) or endovascular aortic repair (n = 197) were divided into three groups: no cyst (n = 204), non-polycystic kidney (n = 503), and polycystic kidney (≥ 5 cysts in the bilateral kidneys, n = 93). The characteristics and outcomes were compared among the groups.

RESULTS

In the polycystic kidney group, the age was increased and the proportions of patients with male sex, hypertension, and estimated glomerular filtration rate < 30 mL/min/1.73 m² were greater. The overall hospital mortality rates were similar. The incidence of acute kidney injury after elective open aortic repair was increased in the polycystic kidney group (12%, 17%, and 29%, P = 0.020). In the polycystic kidney group, 80 patients did not have renal enlargement or a family history of renal disease, while 13 (corresponding to 1.6% [13/800] of the overall patients), had renal enlargement, suggesting the possibility of hereditary polycystic kidney disease.

CONCLUSIONS

In our cohort, 1.6% of the patients with abdominal aortic aneurysm who underwent surgery were at risk of hereditary polycystic kidney disease. Polycystic kidney disease was associated with acute kidney injury after open aortic repair.

Acute Kidney Injury Following Elective Open Aortic Repair with Suprarenal Clamping

Objective: To investigate predictors of acute kidney injury (AKI) following open aortic repair (OAR) requiring suprarenal clamping.

Methods: The study included 833 nonhemodialysis patients who had undergone elective OAR (with suprarenal clamping, n=73; with infrarenal clamping, n=760). We evaluated AKI as defined by the criteria of the Kidney Disease Improving Global Outcomes (KDIGO) and compared in-hospital outcomes between the two groups. We also investigated the effects of AKI on outcomes, factors related to post-suprarenal clamping AKI, and efficacy of hypothermic renal perfusion (HRP) in the suprarenal clamping group.

Results: For the suprarenal vs. infrarenal clamping group, in-hospital mortality was 0% (0/73) vs. 0.5% (4/760). The incidence of AKI was greater in the suprarenal clamping group (37% vs. 15%, P<0.001), and the hospital stay for patients with AKI was longer than for those patients without AKI (median, 21 days vs. 16 days; P=0.005). Renal ischemia time and bleeding volume >1,000 mL were associated with post-suprarenal clamping AKI. Renal ischemia time was longer with HRP (n=15) than without HRP (n=58) (median, 51 min vs. 33 min; P=0.011), and HRP did not decrease the incidence of AKI (40% vs. 36%; P=0.78).

Conclusion: Prolonged renal ischemia and substantial intraoperative bleeding are associated with postoperative AKI following suprarenal clamping.