Incidence, Prognostic Significance, and Risk Factors of Acute Kidney Injury Following Elective Infrarenal and Complex Endovascular Aneurysm Repair

Results of the Italian Collaborators for Evar Registry on Acute Kidney Injury After Elective Endovascular Aortic Repair of Infrarenal Abdominal Aortic Aneurysm

OBJECTIVES

To analyze the incidence and predictive factors of postoperative acute kidney injury (AKI) after elective standard endovascular aortic repair (EVAR) in a large recent, multicenter cohort.

MATERIALS AND METHODS

This is a multicenter, retrospective, financially unsupported physician-initiated observational cohort study. Between January 2018 and March 2021, only patients treated with elective standard EVAR for infrarenal non-infected abdominal aortic aneurysm were analyzed. Patients already on hemodialysis (HD) were excluded. AKI was defined as an increase in serum creatinine (sCr) ≥0.3 mg/dL within 48 hours or an increase in sCr to ≥1.5 times baseline known or presumed to have occurred within 7 days, or a urine volume of <0.5 mL/kg/h for 6 hours. Primary outcomes of interest were AKI incidence at 30 days and freedom from HD at 1-year follow-up. Secondary outcomes were freedom from severe postoperative complication, and freedom from aorta-related mortality (ARM) at 1 year.

RESULTS

The final cohort analyzed 526 (29.8%). There were 489 (93%) males and 37 (7%) females: the median age was 76 years (interquartile range [IQR], 71-81). Chronic kidney disease (CKD) was present in 86 (16.3%) patients. Early mortality was observed in 8 (1.5%) patients, none was aorta-related. Complication rate was 17.1% (n=89). AKI was observed in 17 (3.2%). Renal replacement therapy was needed in 4 (0.8%). HD was transitory in 2 cases and definitive in 1. Binary logistic regression analysis identified CKD (odds ratio [OR]: 4.68, 95% confidence interval [CI]: 2.10-10.45, p<0.001), and the presence of renal artery stenosis (OR: 3.80, 95% CI: 1.35-10.66, p=0.011) to be associated with an increased risk of postoperative AKI. Estimated freedom from ARM was 94.9% at 1 year. Estimated freedom from HD rate at 1 year was 94%: This was significantly different between patients with preoperative CKD and those who did not have preoperative CKD (log-rank, p=0.042).

CONCLUSION

AKI after elective standard EVAR still occurs but with an acceptably low incidence rate. Preoperative CKD is the most important predictor for postoperative AKI, which was not associated with the need for HD at 1-year follow-up but with a higher propensity of mortality.

CLINICAL IMPACT

This "real world" experience confirm that EVAR performed with standard contrats agent protocol remains safe for acute kidney injury development. Therefore, only patients presenting with preoperative borderline or ascertained chronic kidney disease will take the most advantage from the use of carbon dioxide contrast.

Early Versus Delayed Thoracic Endovascular Aortic Repair for Blunt Thoracic Aortic Injury: A Propensity Score-Matched Analysis

OBJECTIVE

We examined early (≤24 h) versus delayed (>24 h) thoracic endovascular aortic repair (TEVAR) for blunt thoracic aortic injury (BTAI), taking the aortic injury severity into consideration.

BACKGROUND

Current trauma surgery guidelines recommend delayed TEVAR following BTAI. However, this recommendation was based on small studies, and specifics regarding recommendation strategies based on aortic injury grades are lacking.

METHODS

Patients undergoing TEVAR for BTAI in the American College of Surgeons Trauma Quality Improvement Program between 2016 and 2019 were included and then stratified into 2 groups (early: ≤24 h vs. delayed: >24 h). In-hospital outcomes were compared after creating 1:1 propensity score-matched cohorts, matching for demographics, comorbidities, concomitant injuries, additional procedures, and aortic injury severity based on the acute aortic syndrome (AAS) classification.

RESULTS

Overall, 1339 patients were included, of whom 1054(79%) underwent early TEVAR. Compared with the delayed group, the early group had significantly less severe head injuries (early vs delayed; 25% vs 32%; P =0.014), fewer early interventions for AAS grade 1 occurred, and AAS grade 3 aortic injuries often were intervened upon within 24 hours (grade 1: 28% vs 47%; grade 3: 49% vs 23%; P <0.001). After matching, the final sample included 548 matched patients. Compared with the delayed group, the early group had a significantly higher in-hospital mortality (8.8% vs 4.4%, relative risk: 2.2, 95% CI: 1.1-4.4; P =0.028), alongside a shorter length of hospital stay (5.0 vs 10 days; P =0.028), a shorter intensive care unit length of stay (4.0 vs 11 days; P <0.001) and fewer days on the ventilator (4.0 vs 6.5 days; P =0.036). Furthermore, regardless of the higher risk of acute kidney injury in the delayed group (3.3% vs 7.7%, relative risk: 0.43, 95% CI: 0.20-0.92; P =0.029), no other differences in in-hospital complications were observed between the early and delayed group.

CONCLUSION

In this propensity score-matched analysis, delayed TEVAR was associated with lower mortality risk, even after adjusting for aortic injury grade.

Post-Operative and Mid-Term Renal Function Impairment Following Elective Fenestrated Endovascular Aortic Repair for Complex Aortic Aneurysms: Incidence and Risk Factors Analysis

Background. The aim of this study was to assess the incidence of two post-operative acute kidney injury (AKI) stages according to the Risk, Injury, Failure, Loss of function, End-stage (RIFLE) criteria in patients undergoing fenestrated endovascular aortic repair (FEVAR) for complex aortic aneurysms. Furthermore, we analyzed predictors of post-operative AKI and mid-term renal function deterioration and mortality. Methods. We included all patients who underwent elective FEVAR for abdominal and thoracoabdominal aortic aneurysms between January 2014 and September 2021, independently from their preoperative renal function. We registered cases of post-operative acute kidney injury (AKI) both at risk (R-AKI) and injury stage (I-AKI) according to the RIFLE criteria. Estimated glomerular filtration rate (eGFR) was noted preoperatively, at the 48th post-operative hour, at the maximum post-operative peak, at discharge, and then during follow-up approximately every six months. Predictors of AKI were analyzed with univariate and multivariate logistic regression models. Predictors of mid-term chronic kidney disease (CKD) (stage ≥ 3) onset and mortality were analyzed using univariate and multivariate Cox proportional hazard models. Results. Forty-five patients were included in the present study. Mean age was 73.9 ± 6.1 years and 91% of patients were males. Thirteen patients (29%) presented with a preoperative CKD (stage ≥ 3). Post-operative I-AKI was detected in five patients (11.1%). The aneurysm diameter, thoracoabdominal aneurysms and chronic obstructive pulmonary disease were identified as predictors of AKI in univariate analysis (OR 1.05, 95% CI [1.005-1.20], p = 0.030; OR 6.25, 95% CI [1.03-43.97], p = 0.046; OR 7.43, 95% CI [1.20-53.36], p = 0.031; respectively), yet none of these factors were significative on multivariate analysis. Predictors of CKD onset (stage ≥3) during follow-up on multivariate analysis were age (HR 1.16, 95% CI [1.02-1.34], p = 0.023), post-operative I-AKI (HR 26.82, 95% CI [4.18-218.10], p < 0.001) and renal artery occlusion (HR 29.87, 95% CI [2.33-309.05], p = 0.013), while aortic-related reinterventions where not significantly associated with this outcome in univariate analysis (HR 0.66, 95% CI [0.07-2.77], p = 0.615). Mortality was influenced by preoperative CKD (stage ≥3) (HR 5.68, 95% CI [1.63-21.80], p = 0.006) and post-operative AKI (HR 11.60, 95% CI [1.70-97.51], p = 0.012). R-AKI did not represent a risk factor for CKD (stage ≥ 3) onset (HR 1.35, 95% CI [0.45-3.84], p = 0.569) or for mortality (HR 1.60, 95% CI [0.59-4.19], p = 0.339) during follow-up. Conclusions. In-hospital post-operative I-AKI represented the main major adverse event in our cohort, influencing CKD (≥ stage 3) onset and mortality during follow-up, which were not influenced by post-operative R-AKI and aortic-related reinterventions.

Kidney Function, Male Gender, and Aneurysm Diameter Are Predictors of Acute Kidney Injury in Patients with Abdominal Aortic Aneurysms Treated Endovascularly

Abdominal aortic aneurysm (AAA) is a degenerative disease of the aortic wall with potentially fatal complications. The widespread adoption of endovascular aneurysm repair (EVAR), which is less invasive and equally (if not more) effective for abdominal aortic aneurysms (AAA), is due to the obvious advantages of the procedure compared to the traditional open repair. As the popularity of endovascular procedures grows, related complications become more evident, with kidney damage being one of them. Although acute kidney injury following EVAR is relatively common, its true incidence is still uncertain. The purpose of this study was to assess the incidence of acute kidney injury among patients treated with endovascular repair of ruptured AAA. In addition, we aimed to determine the predictors of PC-AKI in patients with abdominal aortic aneurysm treated with EVAR.

PATIENTS AND METHODS

We retrospectively analyzed a prospective registry of abdominal aortic aneurysm of 247 patients operated endovascularly at a single center between 2015 and 2021. Due to a lack of clinical data, data of 192 patients were reviewed for postcontrast acute kidney injury. Additional comorbidities were included in this study: hypertension, diabetes mellitus, atrial fibrillation, chronic coronary syndrome, COPD, and chronic kidney disease. Follow-up examinations were performed before the procedure and 48 h after contrast administration.

RESULTS

The group of 36 patients developed PC-AKI, which is 19% of the entire study population. Hypertension, diabetes, chronic kidney disease, male gender, and incidence of PC-AKI were more prevalent in patients with higher aortic aneurysm diameter ≥67 mm. In multiple regression analyses, independent predictors of PC-AKI were serum creatinine, chronic kidney disease, male gender, and aortic aneurysm diameter ≥67 mm.

CONCLUSIONS

One of the major complications after EVAR is acute kidney injury, which is linked to higher death and morbidity rates. Independent risk factors for postcontrast acute kidney injury were chronic kidney disease, male gender, and aortic diameter. Only aortic diameter could be modifiable risk factor, and earlier surgery could be considered to yield better outcomes. More research is critically needed to determine how AKI affects long-term outcomes and to look at preventive options.

Renal transplant recipients undergoing endovascular abdominal aortic aneurysm repair have increased risk of perioperative acute kidney injury but no difference in late mortality

OBJECTIVE

Renal transplant is associated with substantial survival advantage in patients with end-stage renal disease. However, little is known about the outcomes of renal transplant recipients (RTRs) after endovascular abdominal aortic aneurysm repair (EVAR). This study aimed to study the effect of renal transplant on perioperative outcomes and long-term survival after elective infrarenal EVAR.

METHODS

The Vascular Quality Initiative database was queried for all patients undergoing elective EVAR from 2003 to 2021. Functioning RTRs were compared with non-renal transplant recipients without a diagnosis of end-stage renal disease (non-RTRs). The outcomes included 30-day mortality, acute kidney injury (AKI), new renal failure requiring renal replacement therapy (RRT), endoleak, aortic-related reintervention, major adverse cardiac events, and 5-year survival. A logistic regression analysis was used to assess the association between RTRs and perioperative outcomes.

RESULTS

Of 60,522 patients undergoing elective EVAR, 180 (0.3%) were RTRs. RTRs were younger (median, 71 years vs 74.5 years; P < .001), with higher incidence of hypertension (92% vs 84%; P = .004) and diabetes (29% vs 21%; P = .005). RTRs had higher median preoperative serum creatinine (1.3 mg/dL vs 1.0 mg/dL; P < .001) and lower estimated glomerular filtration rate (51.6 mL/min vs 69.4 mL/min; P < .001). There was no difference in the abdominal aortic aneurysm diameter and incidence of concurrent iliac aneurysms. Procedurally, RTRs were more likely to undergo general anesthesia with lower amount of contrast used (median, 68.6 mL vs 94.8 ml; P < .001) and higher crystalloid infusion (median, 1700 mL vs 1500 mL; P = .039), but no difference was observed in the incidence of open conversion, endoleak, operative time, and blood loss. Postoperatively, RTRs experienced a higher rate of AKI (9.4% vs 2.7%; P < .001), but the need for new RRT was similar (1.1% vs 0.4%; P = .15). There was no difference in the rates of postoperative mortality, aortic-related reintervention, and major adverse cardiac events. After adjustment for potential confounders, RTRs remained associated with increased odds of postoperative AKI (odds ratio, 3.33; 95% confidence interval, 1.93-5.76; P < .001) but had no association with other postoperative complications. A subgroup analysis identified that diabetes (odds ratio, 4.21; 95% confidence interval, 1.17-15.14; P = .02) is associated with increased odds of postoperative AKI among RTRs. At 5 years, the overall survival rates were similar (83.4% vs 80%; log-rank P = .235).

CONCLUSIONS

Among patients undergoing elective infrarenal EVAR, RTRs were independently associated with increased odds of postoperative AKI, without increased postoperative renal failure requiring RRT, mortality, endoleak, aortic-related reintervention, or major adverse cardiac events. Furthermore, 5-year survival was similar. As such, while EVAR may confer comparable benefits and technical success perioperatively, RTRs should have aggressive and maximally optimized renal protection to mitigate the risk of postoperative AKI.