Editor's Choice – Acute Kidney Injury (AKI) in Aortic Intervention: Findings From the Midlands Aortic Renal Injury (MARI) Cohort Study

A prospective randomized trial of remote renal ischemic preconditioning for reducing nephropathy risk following fenestrated endovascular aortic aneurysm repair

OBJECTIVES

We sought to evaluate whether remote renal ischemic preconditioning is effective for reducing postoperative acute kidney injury (AKI) and mid-term renal function decline in patients undergoing elective fenestrated endovascular aneurysm repair (FEVAR) of juxtarenal aortic aneurysms.

METHODS

We performed a single-site, blinded, prospective randomized trial of a renal ischemic preconditioning intervention using arm ischemia via manual inflation of arm blood pressure cuff. We evaluated 30-day AKI, determined using the Risk, Injury, Failure, loss of Function, and End-stage (RIFLE) classification and 2-year freedom from renal function decline, defined as a >30% decrease in baseline estimated glomerular function rate. The study was powered to detect a >25% difference in renal injury incidence.

RESULTS

We enrolled 80 patients (80% male; mean aneurysm diameter, 6.1 cm) who were undergoing elective FEVAR using Cook ZFEN devices between July 2018 and August 2023. The 30-day follow-up rate was 95.0%, and mean follow-up duration was 20.2 ± 14.6 months. Although there was a trend to older patient age in the treatment group (77.4 ± 7.8 years vs 74.1 ± 7.0 years), this difference did not reach statistical significance (P = .05). The mean baseline estimated glomerular function rate and creatinine were 69.8 ± 21.0 mL/min/1.73 m2 and 1.1 ± 0.4 mg/dL respectively, and 30.0% had chronic kidney disease stage ≥3. There were no differences in any other baseline or operative metrics between the groups. The rate of AKI at 30 days was 11.3% overall (risk, 7.5%; injury, 2.5%; failure, 1.3%) and did not differ between groups. There were no 30-day deaths. There was no difference in 2-year freedom from renal function decline between treatment groups (56.2% vs 81.1%; log-rank P = .12).

CONCLUSIONS

Renal ischemic preconditioning using arm ischemia did not confer a 30-day AKI or mortality or long-term renal protection benefit in patients undergoing elective FEVAR.

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.

A Systematic Review of Renal Perfusion in Complex Abdominal Aortic Aneurysm Open Repair

INTRODUCTION

This systematic review aims to analyze the current literature regarding 30-day mortality and postoperative acute kidney disease (AKI) in complex abdominal aortic aneurysms (cAAAs), which included juxtarenal aortic aneurysm (JAA), suprarenal aortic aneurysm (SRAA), and type IV thoracoabdominal aortic aneurysm (TAAA) open surgery (OS), to evaluate the impact of renal perfusion on AKI and to try to define which is the best way to perform it.

METHODS

A literature search in PubMed and Cochrane Library was performed, and articles published from January 1986 to January 2024 reporting on JAA, SRAA, and TAAA type IV open surgery management were identified. Multicenter studies, single-center series, and case series with ≥10 patients were considered eligible. Comparisons of outcomes of patients who underwent OS for complex abdominal aortic aneurysms (cAAAs) with or without perfusion of the renal arteries were analyzed when available. The titles, abstracts, and full texts were evaluated by two authors independently. The primary outcomes included AKI and 30-day mortality rates. The new-onset dialysis rate was considered a secondary outcome.

RESULTS

A total of 295 articles were evaluated, and 21 were included, totaling 5708 patients treated for cAAAs with OS. The male patients totaled 4094 (71.7%), with a mean age of 70.35 ± 8.01 and a mean renal ischemia time of 32.14 ± 12.89 min. Data were collected and analyzed, at first in the entire cohort and then divided into two groups (no perfusion of the renal arteries-group A vs. selective perfusion-group B), with 2516 patients (44.08%) who underwent cAAAs OS without perfusion of the renal arteries and 3192 patients (55.92%) with perfusion. In group B, four types of renal perfusion were reported. Among the 21 studies included, 10 reported on selective renal perfusion in cAAA OS, with several types of fluids described: (1) "enriched" Ringer's solution, (2) "Custodiol" (Istidine-tryptophan-ketoglutarate or Custodiol HTKsolution), (3) other cold (4 °C) solutions (i.e., several combinations of 4 °C isotonic heparinized balanced salt solution containing mannitol, sodium bicarbonate, and methylprednisolone), and (4) warm blood. Thirty-day mortality for patients in group A was 4.25% (107/2516) vs. 4.29% (137/3192) in group B. The reported incidence of AKI and new onset of dialysis was, respectively, 22.14% (557/2516) and 5.45% (137/2516) for group A and 22.49% (718/3192) and 4.32% (138/3192) for group B. A total of 579 patients presented with chronic kidney disease (CKD) at admission across all studies, which included 350 (13.91%) in group A vs. 229 (7.17%) in group B. Acute kidney injury, 30-day mortality, and new-onset dialysis rate were reported in four subgroups: (1) In the "Ringer" group, 30-day mortality was 2.52% (3/113), AKI affected 27.73% (33/119) of patients, and the new-onset dialysis rate was 2.52% (3/113). (2) In the "Custodiol" group, 30-day mortality was 3.70% (3/81), AKI affected 20.17% (24/81) of patients, and the new-onset dialysis rate was 2.46% (2/81). (3) In the "cold solutions" group (i.e., NaCl and mannitol), 30-day mortality was 4.38% (130/2966), AKI affected 21.81% (647/2966) of patients, and the new-onset dialysis rate was 4.48% (133/2966). (4) In the "Warm blood" group, 30-day mortality was 3.85% (1/26), AKI affected 53.84% (14/26) of patients, and the new-onset dialysis rate was 0% (0/26).

CONCLUSIONS

This systematic review highlights the lack of standard definitions for AKI, CKD, and the type of renal perfusion. Despite similar results in terms of AKI and 30-day mortality, renal perfusion seems to be protective of the new-onset hemodialysis rate. Moreover, Custodiol appears to have lower rates of AKI and hemodialysis than the other perfusion types. A prospective randomized controlled trial to perform further subgroup analysis and research the various types of renal perfusion may be necessary to identify possible benefits.

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.

Heterogeneity in the definition of major adverse kidney events: a scoping review

Acute kidney injury (AKI) is associated with persistent renal dysfunction, the receipt of dialysis, dialysis dependence, and mortality. Accordingly, the concept of major adverse kidney events (MAKE) has been adopted as an endpoint for assessing the impact of AKI. However, applied criteria or observation periods for operationalizing MAKE appear to vary across studies. To evaluate this heterogeneity for MAKE evaluation, we performed a systematic scoping review of studies that employed MAKE as an AKI endpoint. Four major academic databases were searched, and we identified 122 studies with increasing numbers over time. We found marked heterogeneity in applied criteria and observation periods for MAKE across these studies, with some even lacking a description of criteria. Moreover, 13 different observation periods were employed, with 30 days and 90 days as the most common. Persistent renal dysfunction was evaluated by estimated glomerular filtration rate (34%) or serum creatinine concentration (48%); however, 37 different definitions for this component were employed in terms of parameters, cut-off criteria, and assessment periods. The definition for the dialysis component also showed significant heterogeneity regarding assessment periods and duration of dialysis requirement (chronic vs temporary). Finally, MAKE rates could vary by 7% [interquartile range: 1.7-16.7%] with different observation periods or by 36.4% with different dialysis component definitions. Our findings revealed marked heterogeneity in MAKE definitions, particularly regarding component assessment and observation periods. Dedicated discussion is needed to establish uniform and acceptable standards to operationalize MAKE in terms of selection and applied criteria of components, observation period, and reporting criteria for future trials on AKI and related conditions.

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.

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.

Relationship between preoperative high triglyceride-glucose index and myocardial injury following non-cardiac surgery in advanced-age patients: a retrospective cohort study

BACKGROUND

Myocardial injury after non-cardiac surgery (MINS) is a common and insidious postoperative complication. This study aimed to evaluate the relationship between the triglyceride-glucose index (TyG) and MINS in advanced-age patients.

METHODS

We performed a single-center retrospective study including patients ≥ 65 years of age who underwent non-cardiac surgery. The relationship between TyG and MINS was investigated using univariate and multivariate logistic regression analyses. Multivariate logistic regression analysis involved three models: Model I adjusted for preoperative factors, Model II adjusted for surgery-related factors, and Model III adjusted for both preoperative and surgery-related factors. Propensity score matching (PSM) was used to reduce the confounding effects of covariates. Subgroup analyses were then performed to evaluate the relationship between TyG and MINS in various subsamples.

RESULTS

A total of 7789 patients were studied, among whom 481 (6.2%) developed MINS. A cut-off value of TyG of 8.57 was determined using a receiver operating characteristic (ROC) curve to be associated with the best predictive performance. Participants with TyG ≥ 8.57 were at a higher risk of developing MINS than those with TyG < 8.57 [n = 273 (7.6%) vs. n = 208 (4.9%), respectively; p < 0.001]. The univariate analysis showed that TyG ≥ 8.57 was significantly associated with MINS in elderly patients [odds ratio (OR): 1.58; 95% confidence interval (95%CI): 1.32-1.91; p < 0.001)]. In multivariate logistic regression, adjustments were made for risk factors including age, sex, body mass index (BMI), hypertension, coronary heart disease, and duration of surgery, etc. The adjusted ORs for TyG ≥ 8.57 were 1.46 (95%CI: 1.17-1.82), p = 0.001; 1.46 (95%CI: 1.19-1.77), p < 0.001; and 1.43 (95%CI: 1.13-1.81), p = 0.003, in the three multivariate models, respectively. The relationship remained after PSM (adjusted OR: 1.35, 95% CI: 1.03-1.78, p = 0.029). Furthermore, the relationship between TyG and MINS remained in a number of subgroups in the sensitivity analyses, but not in participants with peripheral vascular stenosis.

CONCLUSIONS

A preoperative high TyG (≥ 8.57) is associated with a higher risk of MINS in advanced-age patients undergoing non-cardiac surgery.

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.

Understanding the current acute aortic syndrome (AAS) pathways-The Collaborative Acute Aortic Syndrome Project (CAASP) protocol

BACKGROUND

Acute aortic syndrome (AAS) is an emergency associated with high peri-hospital mortality rates. Variable clinical presentation makes timely diagnosis challenging and such delays in diagnosis directly impact patient outcomes.

AIMS AND OBJECTIVES

The aims of the Collaborative Acute Aortic Syndrome Project (CAASP) are to characterise and evaluate the current AAS pathways of a cohort of hospitals in the UK, USA and New Zealand to determine if patient outcomes are influenced by the AAS pathway (time to hospital admission, diagnosis and management plan) and demographic, social, geographic and patient-specific factors (clinical presentation and comorbidities). The objectives are to describe different AAS pathways and time duration between hospital admission to diagnosis and management plan instigation, and to compare patient outcomes between pathways.

METHODS

The study is a multicentre, retrospective service evaluation project of adult patients diagnosed on imaging with AAS. It will be coordinated by the UK National Interventional Radiology Trainee Research (UNITE) network and Vascular and Endovascular Research Network (VERN) in conjunction with The Aortic Dissection Charitable Trust (TADCT). All AAS cases diagnosed on imaging between 1st January 2018 to 1st June 2021 will be included and followed-up for 6 months. Eligibility criteria include aortic dissection (AD) Type A, Type B, non A/B, penetrating aortic ulcer, and intramural haematoma. Exclusion criteria are non-AAS pathology, acute on chronic AAS, and age<18. This project will evaluate patient demographics, timing of presentation, patient symptoms, risk factors for AD, physical examination findings, timing to imaging and treatment, hospital stay, and mortality. Univariate and multivariate analysis will be used to identify predictors associated with prolonged time to diagnosis or treatment and mortality at 30 days.

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.

Association of Baseline Chronic Kidney Disease Stage With Short- and Long-Term Outcomes After Fenestrated Endovascular Aneurysm Repair

BACKGROUND

Fenestrated endovascular aneurysm repair (FEVAR) is a well-established treatment approach for juxtarenal and short-neck infrarenal aortic aneurysms. Recommendations and clinical outcomes are lacking for offering FEVAR in patients with chronic kidney disease (CKD). We aimed to compare short- and long-term outcomes for patients with none-to-mild versus moderate-to-severe CKD undergoing FEVAR.

METHODS

We retrospectively reviewed consecutive patients undergoing standard FEVAR with Cook devices at a single institution. The cohort was stratified by preoperative CKD stage none-to-mild or moderate-to-severe (CKD 1-2 and CKD 3-5, respectively). The primary outcome was postoperative acute kidney injury (AKI). Secondary outcomes included 30-day perioperative complications, 1- and 5-year rates of overall survival, dialysis, renal target artery patency, endoleak, and reintervention assessed by the Kaplan-Meier method. Aneurysm sac regression, number of surveillance computed tomography (CT) scans, and CKD stage progression were assessed at latest follow-up. Multivariate Cox proportional hazards modeling was used to evaluate the association of CKD stage 3 and stage 4-5 with all-cause mortality, controlling for differences in baseline characteristics.

RESULTS

From 2012- to 2022, 184 patients (of which 82% were male) underwent FEVAR with the Cook ZFEN device (mean follow-up 34.3 months). Group CKD 3-5 comprised 77 patients (42%), was older (75.2 vs. 73.0 years, P = 0.04), had increased preoperative creatinine (1.6 vs. 0.9 mg/dL, P < 0.01), and demonstrated increased renal artery ostial calcification (37.7% vs. 21.5%, P = 0.02) compared with Group CKD 1-2. Perioperatively, CKD 3-5 sustained higher estimated blood loss (342 vs. 228 ml, P = 0.01), longer operative times (186 vs. 162 min, P = 0.04), and longer length of stay (3 vs. 2 days, P < 0.01). Kaplan-Meier 1- and 5-year survival estimates were lower for CKD 3-5 (82.3% vs. 95.1%, P < 0.01 and 55.4% vs. 70.8%, P = 0.02). Fewer CKD 3-5 patients remained free from chronic dialysis at 1 year (94.4% vs. 100%, P = 0.015) and 5 years (84.7% vs. 100%, P < 0.01). There were no significant differences in postoperative AKI rate (CKD 1-2 6.5% vs. CKD 3-5 14.3%, P = 0.13), long-term renal artery patency, reinterventions, type I or III endoleak, mean sac regression, or total follow-up CT scans between groups. CKD stage progression occurred in 47 patients (31%) at latest follow-up but did not differ between stratified groups (P = 0.17). On multivariable modeling, age (hazard ratio 1.05, 95% confidence interval 1.01-1.09, P = 0.02) and CKD stage 4-5 (hazard ratio 6.39, 95% confidence interval 2.26-18.05, P < 0.01) were independently associated with mortality.

CONCLUSIONS

Preoperative CKD status did not negatively impact the durability or technical success related to aneurysm outcomes after FEVAR. Worsening CKD stage was associated with lower 1- and 5-year overall survival and freedom from dialysis after FEVAR with no statistically significant differences in 30-day or long-term technical aneurysm outcomes.

Severity of acute kidney injury is associated with decreased survival after fenestrated and branched endovascular aortic aneurysm repair

OBJECTIVE

Acute kidney injury (AKI) occurs frequently in complex aortic surgery and has been implicated in perioperative and long-term survival. This study sought to characterize the relationship between AKI severity and mortality after fenestrated and branched endovascular aortic aneurysm repair (F/B-EVAR).

METHODS

Consecutive patients enrolled by the US Aortic Research Consortium in 10, prospective, nonrandomized, physician-sponsored investigational device exemption studies evaluating F/B-EVAR, between 2005 and 2023, were included in this study. Perioperative AKI during hospitalization was defined by and staged using the 2012 Kidney Disease Improving Global Outcomes criteria. Determinants of AKI were evaluated with backward stepwise mixed effects multivariable ordinal logistic regression. Survival was analyzed with conditionally adjusted survival curves and backward stepwise mixed effects Cox proportional hazards modelling.

RESULTS

In the study period, 2413 patients with a median (interquartile range [IQR]) age of 74 years (IQR, 69-79 years) underwent F/B-EVAR. The median follow-up duration was 2.2 years (IQR, 0.7-3.7 years). The median baseline estimated glomerular filtration rate (eGFR) and creatinine were 68 mL/min/1.73 m2 (IQR, 53-84 mL/min/1.73 m2) and 1.1 mg/dL (IQR, 0.9-1.3 mg/dL), respectively. Stratification of AKI identified 316 patients (13%) with stage 1 injury, 42 (2%) with stage 2 injury, and 74 (3%) with stage 3 injury. Renal replacement therapy was initiated during the index hospitalization in 36 patients (1.5% of cohort, 49% of stage 3 injuries). Thirty-day major adverse events were associated with AKI severity (all P ≤ .0001). Multivariable predictors of AKI severity included baseline eGFR (proportional odds ratio, 0.9 per 10 mL/min/1.73 m2 [95% confidence interval (CI), 0.85-0.95 per 10 mL/min/1.73 m2]; P < .0001), baseline serum hematocrit (0.58 per 10% [95% CI, 0.48-0.71 per 10%]; P < .0001), renal artery technical failure during aneurysm repair (3 [95% CI,1.61-5.72]; P = .0006), and total operating time (1.05 per 10 minutes [95% CI, 1.04-1.07 per 10 minutes]; P < .0001). One-year unadjusted survivals for AKI severity strata were 91% (95% CI, 90%-92%) for no injury, 80% (95% CI, 76%-85%) for stage 1 injury, 72% (95% CI, 59-87%) for stage 2 injury, and 46% (95% CI, 35-59%) for stage 3 injury (P<.0001). Multivariable determinants of survival included AKI severity (stage 1, hazard ratio [HR], 1.6 [95% CI, 1.3-2]); stage 2, HR, 2.2 [95% CI, 1.4-3.4]); stage 3 HR, 4 [95% CI, 2.9-5.5]; P < .0001), decreased eGFR (HR, 1.1 [95% CI, 0.9-1.3]; P = .4), patient age (HR, 1.6 per 10 years [95% CI, 1.4-1.8 per 10 years]; P < .0001), baseline chronic obstructive pulmonary disease (HR, 1.5 [95% CI, 1.3-1.8]; P < .0001), baseline congestive heart failure (HR, 1.7 [95% CI, 1.6-2.1]; P < .0001), postoperative paraplegia (HR, 2.1 [95% CI, 1.1-4]; P = .02), and procedural technical success (HR, 0.6 [95% CI, 0.4-0.8]; P = .003).

CONCLUSIONS

AKI, as defined by the 2012 Kidney Disease Improving Global Outcomes criteria, occurred in 18% of patients after F/B-EVAR. Greater severity of AKI after F/B-EVAR was associated with decreased postoperative survival. The predictors of AKI severity identified in these analyses suggest a role for improved preoperative risk mitigation and staging of interventions in complex aortic repair.

The Gender Gap in Aortic Dissection: A Prospective Analysis of Risk and Outcomes

Aortic dissection (AD) is a severe cardiovascular condition that could have negative consequences. Our study employed a prospective design and examined preoperative, perioperative, and postoperative data to evaluate the effects of gender on various medical conditions. We looked at how gender affected the results of aortic dissection (AD). In contrast to female patients who had more systemic hypertension (p=0.031), male patients had higher rates of hemopericardium (p=0.003), pulmonary hypertension (p=0.039), and hemopericardium (p=0.003). Dobutamine administration during surgery significantly raised the mortality risk (p=0.015). There were noticeably more women patients (p=0.01) in the 71 to 80 age group. Significant differences in age (p=0.004), eGFR at admission (p=0.009), and eGFR at discharge (p=0.006) were seen, however, there was no association between gender and mortality. In conclusion, our findings highlight that gender may no longer be such an important aspect of aortic dissection disease as we previously thought, and this information could have an important contribution for surgeons as well as for anesthesiologists involved in the management of acute aortic dissection.

Renal perfusion in complex abdominal aortic aneurysm open repair: a scoping review

INTRODUCTION

To perform a scoping review analyzing the current evidence reporting on acute kidney injury (AKI) after elective open surgery (OS) of complex abdominal aortic aneurysms (c-AAAs) and evaluate the impact of renal perfusion, and the different types of solutions on renal morbidity.

EVIDENCE ACQUISITION

Research questions were defined, and a literature search was performed following the PRISMA guidelines for scoping reviews. Multicenter, single-center observational studies were considered eligible. No abstracts only and unpublished literature were included.

EVIDENCE SYNTHESIS

Two hundred and fifty studies were screened, 20 studies met screening criteria and were included, reporting 1552 patients treated for c-AAAs. The majority did not receive renal perfusion and the others received different types of renal perfusions. Acute kidney injury is a common complication after c-AAAs OS, with an incidence up to 32.5%. Heterogeneity in AKI classifications reduce the ability to compare outcomes after perfusion and nonperfusion strategies. Pre-existing CKD, ischemic injury due to suprarenal aortic clamping are major determinants of AKI after aortic surgery. Most papers reported chronic kidney disease (CKD) at admission. Another debated topic is the indication for renal perfusion during c-AAAs OS. Controversial results for cold renal perfusion have been found.

CONCLUSIONS

In the context of c-AAAs, this review identified the need to standardize the definition of AKI to reduce reporting bias. Besides this, it showed the need to assess the indication for renal perfusion and the type of perfusion solution to be used.

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.

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).

A novel pre-operative risk assessment tool to identify patients at risk of contrast associated acute kidney injury after endovascular abdominal aortic aneurysm repair

OBJECTIVES

Contrast-associated acute kidney injury (CA-AKI) after endovascular abdominal aortic aneurysm repair (EVAR) is associated with mortality and morbidity. Risk stratification remains a vital component of preoperative evaluation. We sought to generate and validate a pre-procedure CA-AKI risk stratification tool for elective EVAR patients.

METHODS

We queried the Blue Cross Blue Shield of Michigan Cardiovascular Consortium (BMC2) database for elective EVAR patients and excluded those on dialysis, with a history of renal transplant, death during procedure, and without creatinine measures. Association with CA-AKI (rise in creatinine > 0.5 mg/dL) was tested using mixed effects logistic regression. Variables associated with CA-AKI were used to generate a predictive model via a single classification tree. The variables selected by the classification tree were then validated by fitting a mixed effects logistic regression model into the Vascular Quality Initiative (VQI) dataset.

RESULTS

Our derivation cohort included 7,043 patients, 3.5% of whom developed CA-AKI. After multivariate analysis, age (OR 1.021, 95% CI 1.004-1.040), female sex (OR 1.393, CI 1.012-1.916), GFR < 30 ml/min (OR 5.068, CI 3.255-7.891), current smoking (OR 1.942, CI 1.067-3.535), COPD (OR 1.402, CI 1.066-1.843), maximum AAA diameter (OR 1.018, CI 1.006-1.029), and presence of iliac artery aneurysm (OR 1.352, CI 1.007-1.816) were associated with increased odds of CA-AKI. Our risk prediction calculator demonstrated that patients with a GFR <30 ml/min, females, and patients with a maximum AAA diameter of > 6.9 cm are at higher risk of CA-AKI after EVAR. Using the VQI dataset (N = 62,986), we found that GFR <30 ml/min (OR 4.668, CI 4.007-5.85), female sex (OR 1.352, CI 1.213-1.507), and maximum AAA diameter > 6.9 cm (OR 1.824, CI 1.212-1.506) were associated with increased risk of CA-AKI after EVAR.

CONCLUSIONS

Herein, we present a simple and novel risk assessment tool that can be used pre-operatively to identify patients at risk of CA-AKI after EVAR. Patients with a GFR < 30 ml/min, maximum AAA diameter > 6.9 cm, and females who are undergoing EVAR may be at risk for CA-AKI after EVAR. Prospective studies are needed to determine the efficacy of our model.

Use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers increases the risk of postoperative acute kidney injury after elective endovascular abdominal aortic aneurysm repair

BACKGROUND

Endovascular abdominal aortic aneurysm repair (EVAR) is the major treatment for abdominal aortic aneurysm (AAA); however, EVAR still carries a considerable risk of acute kidney injury (AKI). The present study aimed to investigate the risk factors for AKI after elective EVAR procedures.

METHODS

This was a retrospective observational study. Eligible patients who underwent EVAR from September 2011 to March 2019 in West China Hospital were included. The primary outcome was the occurrence of AKI within two days after EVAR, which was defined by the Kidney Disease Improving Global Outcomes Clinical Practice Guideline. Demographics, comorbidities, medications, laboratory tests, anatomical parameters of AAA, and relative operative details were collected as variables. Univariable and multivariable logistic regression analyses were applied to identify the risk factors among variables, and covariate interactions were further assessed.

RESULTS

A total of 679 eligible patients were included. The incidence of postoperative AKI was 8.2% (56/679) in the whole cohort, and it was associated with a lower 5-year survival rate (63.5% vs . 80.9%; χ 2  = 4.10; P  = 0.043). The multivariable logistic regression showed that chronic kidney disease (OR, 5.06; 95% CI: 1.43-17.95; P  = 0.012), angiotensin-converting enzyme inhibitors (ACEIs)/angiotensin receptor blockers (ARBs) (OR, 2.60; 95% CI: 1.17-5.76; P  = 0.019), and short neck (OR, 2.85; 95% CI: 1.08-7.52; P  = 0.035) were independent risk factors for postoperative AKI. In the covariate interaction analysis, the effect of ACEIs/ARBs use on postoperative AKI was similar across all subgroups ( P  > 0.05), thereby suggesting a robust effect of ACEIs/ARBs use in all patients undergoing elective endovascular abdominal aortic aneurysm repair.

CONCLUSIONS

Postoperative AKI was associated with lower survival rate, and the use of ACEIs/ARBs was the only adjustable independent risk factor. Clinicians should consider withdrawing ACEIs/ARBs in high-risk patients undergoing elective endovascular abdominal aortic aneurysm repair to prevent postoperative AKI.

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

OBJECTIVE

Acute kidney injury (AKI) is a well known complication following cardiovascular procedures. The objective was to assess the incidence, risk factors, and prognostic significance of AKI after infrarenal endovascular aneurysm repair (EVAR) and complex EVAR (cEVAR; fenestrated or branched EVAR).

METHODS

Consecutive patients undergoing elective infrarenal EVAR or cEVAR between 2000 and 2018 in two large teaching hospitals in the Netherlands were included. AKI was determined by serum creatinine levels increasing > 1.5 times or by an absolute increase of 26.5 mmol/L from baseline value (KDIGO criteria). The primary outcome was incidence of peri-operative AKI development. Secondary outcomes included mid-term renal function (RIFLE criteria), overall survival, and risk factors for AKI development. To determine survival and risk factors for AKI, multivariable Cox regression and logistic regression analyses were performed, accounting for pre-operative renal function and other confounders.

RESULTS

In total, 540 patients who underwent infrarenal EVAR with 147 patients who underwent cEVAR also included. The incidence of AKI was 8.7% (n = 47) in infrarenal EVAR patients and 23% (n = 34) in cEVAR patients (fenestrated EVAR 18%; branched EVAR 38%). In contrast to patients without AKI, the renal function of surviving patients with AKI remained significantly reduced at six weeks and did not return to pre-operative values following infrarenal EVAR (three year estimated glomerular filtration rate [eGFR] 59.3 ± 23.1 mL/min/1.73m2vs. pre-operative eGFR 74.0 ± 21.7 mL/min/1.73m2; p = .006) or following cEVAR (three year eGFR 52.0 ± 23.7 mL/min/1.73m2vs. pre-operative eGFR 65.4 ± 18.6 mL/min/1.73m2; p = .082). After risk adjusted analysis, compared with non-AKI, post-operative AKI development was associated with a higher three year mortality rate following both infrarenal and cEVAR (infrarenal EVAR mortality hazard ratio [HR 1.6, 95% confidence interval [CI] 1.01 - 2.7 [p = .046]; cEVAR mortality HR 2.4, 95% CI 1.1 - 5.2 [p = .033]). Following multivariable logistic regression, pre-operative chronic kidney disease (eGFR < 60 mL/min/1.73m2; odds ratio [OR] 2.2, 95% CI 1.03 - 4.8) and neck diameter (OR 1.1, 95% CI 1.01 - 1.2) were significantly associated with AKI following infrarenal EVAR, whereas for cEVAR only contrast volume (OR 1.1, 95% CI 1.0 - 1.2]) was found to be statistically significantly associated with AKI.

CONCLUSION

AKI is a well described complication following infrarenal EVAR and is common after cEVAR. As AKI seems to be associated with permanent renal deterioration and lower survival, efforts to prevent AKI are essential. Future studies are required to assess what factors are associated with a higher risk of developing AKI following cEVAR.

Effect of contrast administration on the renal function of predialysis patients undergoing fistuloplasty

OBJECTIVE

The aim of this study was to investigate if administration of iodinated contrast during endovascular interventions in arteriovenous fistula (AVF) in patients not requiring dialysis (predialysis patients) (1) negatively affects their renal function and (2) if oral hydration has a protective effect.

METHODS

All pre-dialysis patients who underwent endovascular interventions in AVF between August 2010 and April 2019 were included in the study. During the procedures, 35-50mL of Iodixanol were administered. A pre-hydration protocol was introduced in March 2015. Data were grouped before and after this date. The difference between pre- and post-contrast estimated glomerular filtration rate (eGFR) and the difference between the eGFR of hydrated and non-hydrated groups were calculated.

RESULTS

Eighty four patients who underwent 151 procedures were included in the study. In 60.3% of procedures a mean decrease of 1.35 mL/min/1.73 m² in eGFR was noted (95%CI 1.02, 1.69), while in 35.1% there was a mean increase of 1.06 mL/min/1.73 m² (95%CI 0.84, 1.28). The mean difference between pre- and post-procedure eGFR was -0.44 mL/min/1.73 m² (95% CI -0.72, -0.16) (p=.002). Oral hydration was associated with a smaller mean change in eGFR of -0.32 mL/min/1.73 m² (95%CI -0.62, -0.03) compared to the non-hydrated group with mean change of -0.47 mL/min/1.73 m² (95% CI -0.91, -0.03), but this was not statistically significant (p=.586).

CONCLUSIONS

This study demonstrates that administration of up to 50mL of iodinated contrast for endovascular interventions in AVF in predialysis patients has minimal adverse effect on the eGFR with questionable clinical significance. In addition, oral hydration before and after the procedure has only a mild protective effect against a decrease in eGFR.

Acute Kidney Injury Risk and Contrast Volume in Intact Versus Ruptured Endovascular Aneurysm Repair in the Vascular Quality Initiative

Objective

Renal impairment after repair of ruptured abdominal aortic aneurysm has been associated with post-operative mortality. Acute kidney injury (AKI) risk specifically related to contrast administration in endovascular aneurysm repair (EVAR) for intact vs ruptured aneurysms has not been previously described. It was our objective to evaluate the risk of AKI and the association with contrast administration in EVAR for ruptured (rEVAR) and intact (iEVAR) aneurysm repair in the Vascular Quality Initiative (VQI).

Methods

Adult patients less than 90 years old undergoing EVAR in the VQI without prior abdominal aortic surgery or who were not actively on dialysis preoperatively were included. Patients immediately converted to an open repair were excluded. Patients were grouped by repair urgency, and patient and operative characteristics and outcomes compared. Univariable and multivariable analyses were performed to identify factors associated with the primary outcome of AKI. Survival was evaluated by Kaplan-Meier analysis.

Results

Of 38,775 EVAR patients identified, 86.5% underwent elective surgery for an intact aneurysm, 8.4% had urgent surgery for a symptomatic, intact aneurysm, and 5.1% had emergent repair for a ruptured aneurysm. Significant risk factors for AKI included contrast volume, a preoperative eGFR <30 mL/min, procedure urgency, COPD, congestive heart failure (CHF), and total procedure time. The factor most associated with AKI was aneurysm rupture prior to repair (OR 8.6, CI 7.2-10.3, P <.01). The association of contrast volume with the outcome was the least strong with a 4% increase in risk per 25 mL of contrast (OR 1.04, 95% CI 1.01-1.07). With the development of AKI, postoperative survival was reduced regardless of indication.

Conclusions

Of all factors assessed, aneurysm rupture was the most and contrast volume the least associated with AKI after EVAR. Further studies should evaluate methods of preventing post-EVAR AKI.

The PERCEIVE quantitative study: PrEdiction of Risk and Communication of outcome following major lower-limb amputation: protocol for a collaboratiVE study

BACKGROUND

Accurate prediction of outcomes following surgery with high morbidity and mortality rates is essential for informed shared decision-making between patients and clinicians. It is unknown how accurately healthcare professionals predict outcomes following major lower-limb amputation (MLLA). Several MLLA outcome-prediction tools have been developed. These could be valuable in clinical practice, but most require validation in independent cohorts before routine clinical use can be recommended. The primary aim of this study is to evaluate the accuracy of healthcare professionals' predictions of outcomes in adult patients undergoing MLLA for complications of chronic limb-threatening ischaemia (CLTI) or diabetes. Secondary aims include the validation of existing outcome-prediction tools.

METHOD

This study is an international, multicentre prospective observational study including adult patients undergoing a primary MLLA for CLTI or diabetes. Healthcare professionals' accuracy in predicting outcomes at 30-days (death, morbidity and MLLA revision) and 1-year (death, MLLA revision and ambulation) will be evaluated. Sixteen existing outcome-prediction tools specific to MLLA will be examined for validity. Data collection began on 1 October 2020; the end of follow-up will be 1 May 2022. The C-statistic, Hosmer-Lemeshow test, reclassification tables and Brier score will be used to evaluate the predictive performance of healthcare professionals and prediction tools, respectively.

STUDY REGISTRATION AND DISSEMINATION

This study will be registered locally at each centre in accordance with local policies before commencing data collection, overseen by local clinician leads. Results will be disseminated to all centres, and any subsequent presentation(s) and/or publication(s) will follow a collaborative co-authorship model.

Pre-Operative Moderate to Severe Chronic Kidney Disease is Associated with Worse Short-Term and Mid-Term Outcomes in Patients Undergoing Fenestrated-Branched Endovascular Aortic Repair

OBJECTIVE

To review experience of fenestrated-branched endovascular aortic repair (F-BEVAR) for pararenal/thoraco-abdominal aortic aneurysms (PRAA/TAAA) and to assess the association between pre-operative moderate to severe chronic kidney disease (CKD) and post-operative outcomes.

METHODS

All consecutive patients undergoing (elective and non-elective) F-BEVAR at a single centre (1 January 2011 - 1 July 2019) were identified. Renal function was calculated as the estimated glomerular filtration rate (eGFR) using the Modification of Diet in Renal Disease formula. Accordingly, presence of moderate to severe CKD was defined as eGFR < 60 mL/min/1.73m².

RESULTS

Overall, 202 consecutive patients (mean age 72 ± 8 years; 25% women) underwent F-BEVAR for the treatment of PRAA/TAAA during the study period. Of these, 51 had a history of moderate to severe CKD (none on chronic haemodialysis). No statistically significant differences were found in demographics and major comorbidities between patients with or without a history of CKD. The overall peri-operative mortality rate was 2%, without statistically significant differences between study groups (p = .26). Patients with prior CKD had statistically significantly higher rates of acute kidney injury (AKI) (37% vs. 12%, p < .001). At three years, overall survival was statistically significantly lower in patients with history of CKD compared with those without pre-operative CKD (57% vs. 82%, p = .010). Similarly, freedom from renal function decline at three years was statistically significantly poorer in patients with prior history of CKD compared with those without pre-operative CKD (43% vs. 80%, p = .020). In a multivariable analysis CKD was independently associated with higher odds of peri-operative AKI (OR 2.8, 95% CI 1.9 - 5.8, p = .030), renal function decline (OR 4.9, 95% CI 1.7 - 9.2, p = .003), and all cause mortality (HR 3.2, 95% CI 1.2 - 8.6, p = .020).

CONCLUSION

Despite low peri-operative mortality rates that are comparable to patients with unimpaired renal function, occurrence of AKI was statistically significantly higher in subjects with pre-existing moderate to severe CKD. History of CKD was independently associated to renal function decline and poorer midterm survival.

The impact of the COVID-19 pandemic on vascular surgery: Health care systems, economic, and clinical implications

The novel severe acute respiratory syndrome coronavirus-2 (coronavirus disease 2019 [COVID-19]) pandemic is responsible for more than 500,000 deaths in the United States and nearly 3 million worldwide, profoundly altering the landscape of health care delivery. Aggressive public health measures were instituted and hospital efforts became directed at COVID-19–related concerns. Consequently, routine surgical practice was virtually halted, resulting in billions of dollars in hospital losses as pandemic costs escalated. Navigating an uncertain new landscape of scarce resource allocation, exposure risk, role redeployment, and significant practice pattern changes has been challenging. Furthermore, the overall effect on the financial viability of the health care system and vascular surgical practices is yet to be elucidated. This review explores the economic and clinical implications of COVID-19 on the practice of vascular surgery in addition to the health care system as a whole.

Perioperative and long-term outcome after ascending aortic and arch repair with elephant trunk and open thoracoabdominal aortic aneurysm repair

OBJECTIVE

To describe the outcome of open thoracoabdominal aortic aneurysm (TAAA) repair following previous aortic arch repair including elephant trunk (ET) or frozen elephant trunk (FET) for acute and chronic pathologies.

METHODS

This was a retrospective, observational, multicenter study including 32 patients treated between 2006 and 2019 in two aortic centers using identical surgical protocols. Assessment focused on perioperative and long-term outcome, namely in-hospital morbidity and mortality, as well as procedure-related reintervention rate and aortic-related mortality rate. Kaplan-Meier curves with 95% confidence intervals were used to analyze the overall survival after surgery within the cohort.

RESULTS

Thirty-two patients (mean age, 45.0 ± 13.6 years; 20 males [62.5%]) were treated because of acute (34.38% [n = 11]) or chronic (65.62% [n = 21]) aortic pathologies, including residual dissection following acute, symptomatic type A dissection (n = 7) and symptomatic mega aortic syndrome (n = 4), as well as post-dissection TAAA (n = 18) and asymptomatic mega aortic syndrome (n = 3). Twenty-eight patients (87.5%) received type II repair, and 4 patients (12.5%) received type III repair after previous ascending aorta and arch repair including ET/FET. Concomitant infrarenal and iliac vessel repair was performed in 38.7% (n = 12) and 29.4% (n = 10), respectively. The in-hospital mortality rate was 18.75% (n = 6). Spinal cord ischemia occurred in two cases, both after one-stage emergency procedure with one case of permanent paraplegia. Temporary acute kidney injury occurred in 41.94% (n = 13). The estimated 1-year survival rate was 78.1% (95% confidence interval, 63.9%-95.6%), with a median follow-up time of 1.29 years (interquartile range, 0.26-3.88 years). No procedure-related reinterventions and one case of aortic-related mortality, namely sepsis because of graft infection, was observed.

CONCLUSIONS

Open TAAA repair following aortic arch repair including ET or FET because of acute or chronic aortic pathologies is associated with a relevant perioperative morbidity and mortality rate. During follow-up, a low aortic-related mortality rate and procedure-related reintervention rate were observed.

Impact of Human Umbilical Cord Blood Mononuclear Cells on Gentamicin-Induced Renal Injury and Genotoxicity in Rats

Background: Acute kidney injury (AKI), also known as acute renal failure (ARF), has received considerable critical attention in recent years. Gentamicin (GM) is an antibiotic whose prolonged use results in AKI with a high mortality rate.

Methods: Fifty adult female albino rats weighing 150–200 g were used. The animals were divided into five groups: the first group was the normal healthy control one, the second group received only 1 × 10⁶ HUCB mononuclear cells (MNCs)/rat by intravenous (iv) injection, the third diseased group was given GM 100 mg/kg for 10 consecutive days by intraperitoneal injections, the fourth preventive group received 1 × 10⁶ HUCB MNCs/rat by iv injection 24 h before gentamicin treatment, and the fifth treated group received 1 × 10⁶ HUCB MNCs/rat by iv injection 24 h after gentamicin treatment. After 1 week of treatment, blood samples were collected, and kidneys were removed for histopathological examination.

Results: Rats treated with HUCB MNCs in the treated group had a significant decrease in renal damage, low levels of biomarkers for nephrotoxicities such as serum creatinine and blood urea nitrogen, and low chromosomal aberrations compared to the diseased third group. The gene expression of KIM-1 and NGAL was decreased in response to HUCB treatment.

Conclusions: HUCB MNCs have a curative effect against AKI and gentamicin-induced genotoxicity owing to their regenerative property.

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.

Clinical effect of accessory renal artery coverage after endovascular repair of aneurysms in abdominal and thoracoabdominal aorta

BACKGROUND

The aim of our systematic review and meta-analysis was to assess the effect of accessory renal artery (ARA) coverage on renal function in terms of acute kidney injury (AKI), renal infarction, chronic renal failure (CRF), and mortality in patients undergoing standard endovascular aortic aneurysm repair (EVAR) or endovascular repair of complex aneurysms.

METHODS

An electronic search of the English language medical literature from 2000 to September 2020 was conducted using the MEDLINE, EMBASE, and Cochrane databases with the PRISMA (preferred reporting items for systematic reviews and meta-analyses) method for studies reporting on ARA management in patients undergoing endovascular repair of aneurysms in the abdominal and thoracoabdominal aorta. The patients were divided into two groups: group 1, patients with ARA coverage; and group 2, patients without an ARA or without coverage of the ARA. Each group included two arms, one of patients who had undergone standard EVAR and one of patients who had undergone endovascular treatment of a complex aortic aneurysm. The GRADE (grading of recommendations assessment, development, evaluation) approach was used to evaluate the quality of evidence and summary of the findings. The primary outcomes included the incidence of AKI, renal infarction, CRF, and mortality.

RESULTS

Ten retrospective, nonrandomized, control studies were included in the systematic review reporting on 1014 patients (302 with a covered ARA vs 712 without an ARA or without ARA coverage). In six studies, the mean diameter of the covered ARA was <4 mm (range, 2.7-3.4 mm). The mean follow-up was 22.74 months (range, 1-42 months). In the standard EVAR subgroup, the risk of AKI (odds ratio [OR], 0.72; 95% confidence interval [CI], 0.21-2.51; I² = 0%] in the early period, and CRF (OR, 4.44; 95% CI, 0.46-42.61; I² = 87%) and death (OR, 0.91; 95% CI, 0.36-2.31; I² = 0%) during follow-up were similar between groups 1 and 2. Only the risk of renal infarction was greater in group 1 than in group 2 (OR, 93.3; 95% CI, 1.48-5869; I² = 92%). In the complex aneurysm repair subgroup, the risk of AKI (OR, 1.85; 95% CI, 0.61-5.64; I² = 42%) in early period and CRF (OR, 1.64; 95% CI, 0.88-3.07; I² = not applicable) and death (OR, 3.63; 95% CI, 0.14-96.29; I² = 56%) during follow-up were similar between groups 1 and 2. Only the risk of renal infarction was greater for group 1 compared with group 2 (OR, 8.58; 95% CI, 4.59-16.04; I² = 0%).

CONCLUSIONS

ARA (<4 mm) coverage in patients undergoing standard EVAR or endovascular repair of complex aneurysms is associated with an increased risk of renal infarction. However, we found no clinical effects of ARA coverage on renal function or mortality in early postoperative and follow-up period. Preservation of an ARA >4 mm should be considered.

Proximal fixation of endovascular aortic device may not be associated with renal function decline after abdominal aortic aneurysm repair

OBJECTIVE

Significant debate exists among providers who perform endovascular abdominal aortic aneurysm repair (EVAR) regarding the renal function change between suprarenal (SuF) and infrarenal (InF) fixation devices. The purpose of this study is to review our institution's experience using these devices in terms of renal function.

METHODS

This is a retrospective review of all elective EVARs performed within a three-site health system (Florida, Minnesota, and Arizona) during the period of 2000 to 2018. The primary outcome was renal function decline on long-term follow-up depending on the anatomical fixation of the device (SuF vs InF). Secondary outcomes were length of hospitalization (LOH) and progression to hemodialysis. Multivariable regression analysis was performed to test for associations affecting LOH.

RESULTS

There were 1130 elective EVARs included in our review. Of those, 670 (59.3%) had SuF and 460 (40.7%) InF. Long-term follow-up was 4.8 ± 3.7 years, and the rate of change in creatinine and estimated glomerular filtration rate (eGFR) were not statistically significant among groups (SuF vs InF). LOH was higher in those individuals with a SuF device (3.4 ± 2.2 vs 2.3 ± 1.0 days; P < .001). Ten patients with chronic kidney disease progressed to hemodialysis at 6.7 ± 3.8 years from EVAR. On Kaplan-Meier analysis, patients with chronic kidney disease with SuF were more likely to progress to hemodialysis (P = .039). On multivariable regression, female sex (Coef, 2.4; 95% confidence interval [CI], 0.17-0.41; P = .02), SuF (Coef, 9.5; 95% CI, 0.11-1.11; P < .0001), and intraoperative blood loss of greater than 150 mL (Coef, 15.4; 95% CI, 0.11-1.76; P < .0001) were predictors of prolonged LOH.

CONCLUSION

Our three-site, single-institution data indicate that, although the starting eGFR was statistically lower in those individuals undergoing elective EVAR with InF, device fixation type did not affect the creatinine and eGFR on long-term follow-up. However, caution should be exercised at the time of abdominal aortic aneurysm repair in those individuals who already presented with renal dysfunction.

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.

A Review of UK-based National and International Scientific Meeting Published Abstracts in Response to the Draft NICE Aortic Aneurysm Guidelines

BACKGROUND

UK National Institute for Health and Care Excellence (NICE) draft clinical guidelines (CG) (2018) regarding aortic aneurysm repair were disputed internationally. We aim to appraise the academic response to the draft CG in terms of quantity and scientific quality by reviewing published conference abstracts from three major national and international, UK meetings.

METHODS

Abstracts related to aortic practice from The Vascular Societies Annual Scientific Meeting, British Society for Endovascular Therapy (BSET) & Charing Cross (CX) meetings from 2019 were reviewed for methodology, sample size, data collection period, scientific quality and conclusions that supported or conflicted the draft guideline.

RESULTS

A total of 549 abstracts were identified from VSGBI, BSET and CX abstract books of which, 226 (41.2%) were related to aortic practices. Of these, 115 (50.9%) were related to EVAR. Twenty-two of these abstracts (19.1%) were identified as having findings relevant to the draft guidelines. Eighteen (15.7%) were identified as findings that potentially conflict the draft CG and 4 (3.5%) that could support the initial recommendations. Six abstracts (5.2%) made direct reference to or challenged the draft CG. The median data collection period was 4 years. The median sample size was 102 patients. In general, scientific quality was poor, with 82% of selected abstracts were graded at level 2b.

CONCLUSION

We have demonstrated a concerted response to the draft NICE clinical guidelines relating to the treatment of abdominal aortic aneurysms at three large scientific meetings. As a result of which and other factors, significant changes were made to the finalized NG156. There is still paucity in evidence regarding the long-term safety and cost-effectiveness of EVAR.

Groin wound Infection after Vascular Exposure (GIVE) Study Group. Groin wound infection after vascular exposure (GIVE) multicentre cohort study

Surgical site infections (SSIs) of groin wounds are a common and potentially preventable cause of morbidity, mortality, and healthcare costs in vascular surgery. Our aim was to define the contemporaneous rate of groin SSIs, determine clinical sequelae, and identify risk factors for SSI. An international multicentre prospective observational cohort study of consecutive patients undergoing groin incision for femoral vessel access in vascular surgery was undertaken over 3 months, follow-up was 90 days. The primary outcome was the incidence of groin wound SSI. 1337 groin incisions (1039 patients) from 37 centres were included. 115 groin incisions (8.6%) developed SSI, of which 62 (4.6%) were superficial. Patients who developed an SSI had a significantly longer length of hospital stay (6 versus 5 days, P = .005), a significantly higher rate of post-operative acute kidney injury (19.6% versus 11.7%, P = .018), with no significant difference in 90-day mortality. Female sex, Body mass index≥30 kg/m2 , ischaemic heart disease, aqueous betadine skin preparation, bypass/patch use (vein, xenograft, or prosthetic), and increased operative time were independent predictors of SSI. Groin infections, which are clinically apparent to the treating vascular unit, are frequent and their development carries significant clinical sequelae. Risk factors include modifiable and non-modifiable variables.

Study protocol for COvid-19 Vascular sERvice (COVER) study: The impact of the COVID-19 pandemic on the provision, practice and outcomes of vascular surgery

BACKGROUND

The novel Coronavirus Disease 2019 (COVID-19) pandemic is having a profound impact on global healthcare. Shortages in staff, operating theatre space and intensive care beds has led to a significant reduction in the provision of surgical care. Even vascular surgery, often insulated from resource scarcity due to its status as an urgent specialty, has limited capacity due to the pandemic. Furthermore, many vascular surgical patients are elderly with multiple comorbidities putting them at increased risk of COVID-19 and its complications. There is an urgent need to investigate the impact on patients presenting to vascular surgeons during the COVID-19 pandemic.

METHODS AND ANALYSIS

The COvid-19 Vascular sERvice (COVER) study has been designed to investigate the worldwide impact of the COVID-19 pandemic on vascular surgery, at both service provision and individual patient level. COVER is running as a collaborative study through the Vascular and Endovascular Research Network (VERN), an independent, international vascular research collaborative with the support of numerous national and international organisations). The study has 3 'Tiers': Tier 1 is a survey of vascular surgeons to capture longitudinal changes to the provision of vascular services within their hospital; Tier 2 captures data on vascular and endovascular procedures performed during the pandemic; and Tier 3 will capture any deviations to patient management strategies from pre-pandemic best practice. Data submission and collection will be electronic using online survey tools (Tier 1: SurveyMonkey® for service provision data) and encrypted data capture forms (Tiers 2 and 3: REDCap® for patient level data). Tier 1 data will undergo real-time serial analysis to determine longitudinal changes in practice, with country-specific analyses also performed. The analysis of Tier 2 and Tier 3 data will occur on completion of the study as per the pre-specified statistical analysis plan.

Global impact of the first coronavirus disease 2019 (COVID-19) pandemic wave on vascular services

This online structured survey has demonstrated the global impact of the COVID-19 pandemic on vascular services. The majority of centres have documented marked reductions in operating and services provided to vascular patients. In the months during recovery from the resource restrictions imposed during the pandemic peaks, there will be a significant vascular disease burden awaiting surgeons. One of the most affected specialties.