Long-term decline in renal function is more significant after endovascular repair of infrarenal abdominal aortic aneurysms

Open Conversion with Explantation of Stent Grafts After Endovascular Aneurysm Repair for Abdominal Aortic Aneurysm

BACKGROUND

Although endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) is widely used worldwide, the fact that it is associated with increased rates of reintervention has been considered a problem. This study aimed to analyze the outcomes of primary open AAA repair and open conversion with explantation of stent grafts after EVAR.

METHODS

In this retrospective study, we enrolled 1,120 patients (open repair, n = 664; EVAR, n = 456) who underwent AAA repair at Kobe University from 1999 to 2019. Of the 664 patients who underwent open repair, 121 (patients who underwent primary open repair (POR) as a concomitant procedure and patients with ruptured AAA) were excluded from the study. The outcomes of POR were compared with those of open conversion with explantation of stent grafts.

RESULTS

Of the 543 patients who underwent open repair, 513 underwent POR and 30 underwent open conversion with explantation of stent grafts. The operation time for POR was significantly less than that for open conversion with explantation. During surgery, patients who underwent open conversion with explantation required significantly more transfusions of red cell concentrate, fresh frozen plasma, and platelet concentrate than those who underwent POR. Overall, 30 patients who underwent open conversion with explantation required a total of 48 reinterventions before surgery. Hospital mortality rates were 0.7% and 0% in the POR and open conversion with explantation groups, respectively (P = 0.62). Although overall survival at 5 years in the POR group was significantly better than that in the open conversion with explantation group (89.3 ± 1.7% vs. 79.5 ± 9.6%; P = 0.01), there were no significant differences between the 2 groups regarding the freedom from aortic event (hospital death, reintervention, and aortic death). According to the multivariate analysis, open conversion with explantation was not an independent risk factor for late death. There were 20 patients who were hesitant to undergo OCE, although we recommended OCE. In a subgroup analysis, the overall mean cost borne by patients who underwent EVAR was approximately 2.3 times higher compared with that borne by patients who underwent POR.

CONCLUSIONS

Although demanding, both early and long-term outcomes of OCE have been favorable in our present study. OCE is highly recommended in patients with persistent sac enlargement after EVAR.

Duplex Ultrasound Only Surveillance After Endovascular Abdominal Aortic Aneurysm Repair is Associated with Favorable Long-Term Outcomes

OBJECTIVE

Long-term data surrounding the impact of different endovascular abdominal aortic aneurysm repair (EVAR) surveillance strategies is limited. Therefore, the purpose of this study was to characterize postoperative imaging patterns, as well as to evaluate the association of duplex ultrasound surveillance after the first postoperative year with 5-year EVAR outcomes.

METHODS

EVAR patients (2003-2016), who survived at least 1-year without aneurysm rupture, conversion to open repair, and reintervention in the Vascular Implant Surveillance and Interventional Outcomes Network (VISION) were examined to provide all subjects ≥3-years of follow-up time. Patients were categorized into 6 cohorts after the first postoperative year: No imaging (N=953); CT/MRI-only (N=2,976); Duplex ultrasound-only (DUS; N=1,808); Combined CT/MRI+DUS with >50% being CT/MRI (N=1,937); Combined CT/MRI+DUS with >50% being DUS (N=2,253); and Mixed (CT+DUS+MRI-N=1,272). Abdominal aortic aneurysm (AAA) related re-intervention, rupture, conversion to open repair, and all-cause mortality were estimated using Kaplan-Meier analysis. Multivariable logistic regression models identified variables associated with using DUS-only imaging (vs. CT/MRI only). Cox regression models compared 5-year outcomes between patients receiving DUS-only vs. CT/MRI-only imaging.

RESULTS

A total of 11,199 EVAR patients were examined (mean age-76±7 years; female-20%; non-elective-10%). DUS-only imaging surveillance after the first postoperative year was more likely to occur after elective repairs, as well as among older, male patients. Smaller (<6cm) preoperative AAA diameter and absence of documented concurrent iliac aneurysm was also associated with DUS-only follow-up. Additionally, no endoleak detection on index EVAR completion imaging, as well as a documented >5mm decrease in AAA sac diameter at 1-year follow-up was more common with DUS-only surveillance protocols. Post-EVAR DUS-only imaging after the first postoperative year had the lowest incidence of re-intervention, conversion to open repair, and rupture (as well as the composite reintervention/open conversion/rupture; log-rank P<.001 for all). Further, patients receiving exclusively DUS after their first postoperative year had better overall survival (log-rank P<.001). These outcome advantages that were associated with DUS-only surveillance compared with CT/MRI-only surveillance after EVAR persisted when controlling for baseline co-variates, preoperative AAA diameter, prior aortic surgery history, sac growth, and presence of endoleak (all P<.01).

CONCLUSIONS

EVAR patients selected for DUS-only surveillance after the first postoperative year have excellent freedom from AAA-related reintervention, conversion to open repair, rupture and all-cause mortality. These findings remained on multivariable analysis after adjusting for baseline characteristics, endoleak status and sac diameter changes within the first year. This is the first registry-based investigation to document long-term EVAR outcomes for patients entered into a DUS-only monitoring protocol which serves to corroborate the growing evidence base that DUS may be able to supplant CT surveillance in certain subgroups. A prospective randomized multi-center trial comparing DUS versus CT-based imaging after EVAR is needed to validate these findings which may serve to change current practice guidelines, as well as industry and regulatory stakeholder requirements.

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.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Evaluando la experiencia local: primeros 50 casos de reparo endovascular de aneurismas aórticos en Manizales, Colombia

Introducción. En las últimas décadas, la terapia endovascular en aneurismas aórticos abdominales ha ganado un papel representativo en los escenarios quirúrgicos, lo que nos motivó a conocer los resultados de este procedimiento en nuestra población. Métodos. Estudio analítico retrospectivo en el cual se incluyeron los primeros 50 casos de aneurismas aórticos abdominales con terapia endovascular, en la ciudad de Manizales, Colombia, entre los años 2015 y 2021. Se describió la población estudiada, la relación de los antecedentes prequirúrgicos con las complicaciones posoperatorias, la estancia hospitalaria y la mortalidad. Resultados. La edad promedio fue de 73 años, el sexo predominante fue el femenino (72 %), el aneurisma fusiforme fue el tipo más frecuente (63,3 %), con un diámetro promedio de 70 mm (+/- 17,3 mm). En relación con los antecedentes, el más frecuente fue hipertensión arterial (86 %), encontrándose una asociación entre la presencia de enfermedad pulmonar obstructiva crónica e hipertensión arterial con las complicaciones. Se encontró también relación entre el valor de creatinina con las complicaciones. Las complicaciones tempranas fueron de carácter leve en la mayoría de los casos (30,6 %), a diferencia de las tardías, que fueron principalmente graves (12,5 %), asociadas a una mortalidad del 10,2 % y una estancia hospitalaria promedio de 10,8 días (mediana de 5 días). Conclusiones. La población analizada tiene una alta carga de morbilidad, en la cual factores como los antecedentes médicos prequirúrgicos y la función renal, se asocian con una mayor morbilidad postquirúrgica y mortalidad.

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.

Predictors of Decline in Renal Function 5 Years after EVAR

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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

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

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

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Fenestrated Endovascular Aneurysm Repair Affords Fewer Renal Complications than Open Surgical Repair for Juxtarenal Abdominal Aortic Aneurysms in Patients with Chronic Renal Insufficiency

OBJECTIVE

Although fenestrated endovascular aneurysm repair (FEVAR) has been associated with lower morbidity and mortality than open surgical repair (OSR) in juxtarenal aneurysms (JAAA), there is a paucity of data in the literature comparing outcomes of the approaches specifically in patients with chronic renal insufficiency (CRI). We hypothesized that benefits of FEVAR over OSR observed in the general patient population may be diminished in CRI patients due to their heightened vulnerability to renal dysfunction stemming from contrast-induced nephropathy. This study compares 30-day outcomes between FEVAR and OSR for JAAA in patients with non-dialysis dependent CRI.

METHODS

All adults with estimated glomerular filtration rate (eGFR) < 60 mL/min (but not requiring dialysis) undergoing elective, non-ruptured JAAA repairs were identified in the American College of Surgeons - National Surgical Quality Improvement (ACS-NSQIP) Targeted EVAR and AAA databases from 2012-2018. JAAA were identified by recorded proximal aneurysm extent. FEVAR patients were identified in the Targeted EVAR database as those receiving the "Cook Zenith Fenestrated" endograft. OSR cases were defined as those that required proximal clamp positions "above one renal" or "between SMA & renals." Infra-renal or supra-celiac proximal clamp placement, or cases involving concomitant renal/visceral revascularization were excluded. Thirty-day outcomes including mortality, major adverse cardiovascular events (MACE), pulmonary, and renal complications were compared between FEVAR and OSR groups.

RESULTS

There were 284 patients with CRI who underwent elective repair of JAAA (FEVAR: 89; OSR: 195). FEVAR patients were significantly older than those undergoing OSR (77.3±7.2 vs. 74.2±7.7, P=0.001) and less likely to be smokers (25.8% vs 42.1%; P = 0.009). Other baseline demographic and pre-operative parameters were comparable between the two groups.Multivariable analysis revealed no significant difference between FEVAR and OSR in 30-day mortality (4.5% vs 4.6%; OR=1.22; 95% CI=0.35 - 4.22; P=0.753) or unplanned re-operation (4.5% vs 5.1%; OR=0.78; 95% CI=0.22 - 2.70; P=0.693). Patients undergoing FEVAR had significantly fewer pulmonary complications (3.4% vs 18.5%; OR=0.12; 95% CI=0.03 - 0.42; P<0.001) and renal dysfunction (3.4% vs 11.8%; OR 0.24 95% CI=0.07 - 0.86; P=0.029) compared to OSR. FEVAR was also associated with significantly shorter ICU and hospital lengths of stay (ICU stay: 0 days vs 3 days, P<0.0001; hospital stay: 3 days vs 8 days, P<0.0001).

CONCLUSION

For patients with chronic renal insufficiency, FEVAR offered improved perioperative renal morbidity compared to OSR without a corresponding mortality benefit. Future studies will be required to determine long term outcomes of this procedure in this vulnerable population.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The risk of renal function deterioration in abdominal aortic stent graft patients with and without previous kidney function failure - an analysis of risk factors

Purpose

Kidney failure influences the treatment outcomes of abdominal aortic aneurysm (AAA). A prospective study of renal function before and after aortic stent-graft treatment was performed. Special attention was paid to the influence of preoperative kidney function as well as the impact of the radiological follow-up.

Material and methods

A total of 214 endovascularly treated AAA patients were included. In all cases, pre- and postope-rative estimated glomerular filtration rate (eGFR) and serum creatinine were noted. Patients were prospectively followed up for a minimum of two years.

Results

The baseline eGFR was 69.38 ± 16.29 ml/min/1.73 m². Chronic kidney disease at baseline was noted in 29% of patients. In the direct postoperative period, acute kidney injury was identified in 8.4% of cases. Additional endo-vascular procedures within two years of observation were performed in 5.6% of cases, and over the two years of follow-up, in the study group from one to six angio-computed tomographic scans (angio-CT) per patient were performed. The mean eGFR value after the 24-month follow-up was significantly lower than the preoperative value. Among the factors influencing kidney function, an angio-CT during the same hospital stay of the primary stent-graft procedures was identified. The type of stent-graft, contrast volume during the primary procedure, need for reintervention, concomitant disease presence, and statin use did not show statistical significance.

Conclusions

Angio-CT followed by stent-graft implantation over a short time interval (within the same hospitalisation) significantly worsened renal function in the late follow-up and should be avoided in elective AAA cases.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Endovascular Aneurysm Repair Assisted by CO2 Digital Subtraction Angiography and Intraoperative Contrast-Enhanced Ultrasonography: Single-Center Experience

BACKGROUND

Allergy to iodinated contrast (IC) agent and advanced chronic kidney disease are major limitations to endovascular repair (EVAR) of abdominal aortic aneurysms (AAAs). We describe our experience combining CO₂-assisted EVAR with intraoperative contrast-enhanced ultrasound (CEUS) in an attempt to avoid contrast-induced allergy or nephropathy.

METHODS

Observational cohort study using prospectively acquired data on patients undergoing CO₂-assisted EVAR in single institution. EVAR planning was performed using computed tomographic angiography or magnetic resonance aortography in patients contraindicated for IC. Patients were considered if their estimated glomerular filtration rate was <40 mL/min and anatomically suitable for conventional infrarenal EVAR. Outcomes of interest included technical success rate and reintervention rates, total radiation dose, length of hospital stay, and graft kinking or migration.

RESULTS

Fifteen patients (10 male) were treated across a 5-year period. Technical success was achieved in all cases. Completely IC-free EVAR was performed in 9 cases, whereas the remaining 6 required IC administration for adjunct procedures. CO₂ completion angiography detected all type I endoleaks (2 Ia and 1 Ib) but was less sensitive to type II. Intraoperative CEUS confirmed all type I and 2 cases of type II endoleaks. Median hospital stay was 4 days. No significant deterioration in renal function was seen postoperatively.

CONCLUSIONS

In patients with abdominal aortic aneurysms and with contraindication for IC, a combined approach of using CO₂ digital subtraction angiography and CEUS can be used safely and efficiently to minimize or obviate the need for IC agents with satisfactory mid-term results.

Outcomes of fenestrated-branched endovascular aortic repair in patients with a solitary functional kidney

OBJECTIVE

The aim of this study was to evaluate outcomes of fenestrated-branched endovascular aortic repair (F-BEVAR) of pararenal abdominal aortic aneurysms or thoracoabdominal aortic aneurysms (TAAAs) in patients with a solitary functional kidney (SFK).

METHODS

We analyzed the outcomes of 287 consecutive patients (206 male; mean age, 74 ± 8 years old) enrolled in a prospective nonrandomized study to investigate use of F-BEVAR for treatment of patients with pararenal abdominal aortic aneurysms or TAAAs between 2013 and 2018. Outcomes were analyzed in patients with solitary kidney (functional or congenital) and compared with control patients who had two functioning kidneys. Acute kidney injury (AKI) was defined using Risk, Injury, Failure, Loss of kidney function, and End-stage renal disease criteria, and renal function deterioration (RFD) was defined by a decline in estimated glomerular filtration the estimated glomerular filtration rate of more than 30% from baseline. End points included 30-day mortality and major adverse events, AKI, freedom from RFD, and patient survival.

RESULTS

There where 30 patients (10%) with a SFK and 257 patients with two functioning kidneys. Patients with a SFK were younger and had significantly (P < .05) higher baseline creatinine (+0.3 mg/dL), lower estimated glomerular filtration rate (-16 mL/minute/1.73 m²) and more often had stage III to V chronic kidney disease (73% vs 43%). There were no differences in cardiovascular risk factors and aneurysm extent. Technical success was achieved in 98.9% of patients with SFK and in 99.8% of controls (P = .10). At 30 days, there was no significant differences in mortality (0% vs 1%) and major adverse events (40% vs 24%; P = .08), including rates of AKI (20% vs 12%) and new-onset dialysis (3% vs 1%) between patients with a SFK and the control group, respectively. Mean follow-up was 18 ± 15 months. At 2 years, there was no difference (P = .36) in patient survival (92 ± 5% vs 84 ± 3%) and freedom from RFD (100 ± 0% vs 84 ± 3%) for patients with SFK and controls, respectively. Presence of a SFK was not a predictor for AKI or RFD. By multivariable analysis, estimated blood loss of more than 1 L (odds ratio [OR], 2.9; P = .04) and total fluoroscopy time (OR, 1.8; P = .05) were predictors for AKI, and postoperative AKI (OR, 4.9; P < .001), renal branch occlusion/stenosis (OR, 3.1; P = .001), and Crawford extent II TAAA (OR, 2.4; P = .007) were predictors for RFD.

CONCLUSIONS

Despite the worse baseline renal function, F-BEVAR is safe and effective with nearly identical outcomes in patients with a SFK as compared with patients with two functioning kidneys. Development of postoperative AKI is the most important predictor for RFD.

The effect of Endovascular Aneurysm Repair on Renal Function in Patients Treated for Abdominal Aortic Aneurysm

Aim:

The effect of endovascular aneurysm repair in patients treated for abdominal aortic aneurysm has not been clearly defined. The objective of the present article was to provide a contemporary literature review and perform an analysis to determine the effect of EVAR on renal function in the early post-operative period and during follow-up.

Methods:

A systematic review of the literature was undertaken to identify all studies reporting the effect of EVAR on renal function. Outcome data were pooled and combined overall effect sizes were calculated using fixed or random-effects models.

Results:

Thirty-two studies reporting on 24846 patients were included. Acute renal failure after EVAR occurred with an estimated frequency of 9% (95%CI: 5-16%; I2=97%). Median follow-up period was 19.5 months (range 1-60 months). The estimated frequency of chronic renal failure during follow-up was 7% (95%CI: 3-17%; I2=98%). Hemodialysis was required in 2% (1-3%; I2=97%) of the cases.

Conclusion:

High-level evidence demonstrating the effect of EVAR on the incidence of acute and chronic renal failure is lacking. Based on the current available data, nearly 10% of patients undergoing EVAR for AAA have an increased risk for renal dysfunction after the procedure. Whether this deterioration may lead to a worse outcome has not been adequately proved.

Intra-arterial catheter-directed CT angiography for assessment of endovascular aortic aneurysm repair

OBJECTIVE

To compare the efficacy and safety as well as associated image quality of catheter-directed CT angiography (CCTA) with a low dose of iodine contrast agent compared to intravenous CTA in patients undergoing endovascular aortic aneurysm repair (EVAR).

METHODS

Retrospective data analysis of 92 patients undergoing EVAR between January 2009 and December 2017 was performed. Patients were divided in two groups; those receiving CTA (n = 59) after intravenous contrast agent application and those receiving CCTA (n = 33) via an intraarterial catheter placed in the descending aorta. Demographic and cardiovascular risk factors as well as renal function parameters before, immediately after and 6-60 months after EVAR were evaluated. As primary endpoint, changes in serum creatinine levels in the two groups were evaluated. Secondary endpoints encompassed complications associated with intraarterial catheter placement. Objective (signal-to-noise ratios) and subjective image quality (5-point Likert scale) were compared.

RESULTS

Amount of contrast medium was significantly lower in CCTA compared to i.v. CTA (23 ± 7 ml vs. 119 ± 15 ml, p<0.0001). Patients undergoing catheter-directed CTA had higher baseline creatinine values compared to the group with intravenous iodine application (1.9 ± 0.6 mg/dl vs. 1.3 ± 0.5 mg/dl; p<0.0001). Follow-up serum creatinine levels however did not show significant alterations between the two groups (1.9 ± 0.4 mg/dl vs. 1.3 ± 0.5 mg/dl). No major complications were detected in the CCTA group. Signal-to-noise ratio (SNR) was comparable between i.v. CTA and CCTA (8.5 ± 4.6 vs. 7.7 ± 4.0; p = 0.37) and subjective image similarly revealed no differences with a good interobserver agreement (ICC = 0.647).

CONCLUSIONS

Catheter-directed CTA is safe and provides comparable image quality with a substantial retrenchment of the needed amount of iodine-based contrast medium. However, no benefit of the reduced contrast medium protocol with respect to renal function was observed.

Renal function after abdominal aortic aneurysm repair in patients with baseline chronic renal insufficiency: open vs. endovascular repair

BACKGROUND

The aim of this study is to analyze renal function impairment (RFI) after abdominal aortic aneurysm (AAA) repair in patients with preoperative chronic kidney disease (CKD).

METHODS

Retrospective cohort study of patients with CKD undergoing elective AAA repair between 2008-2015, dividing the sample into two groups: open repair (OR) and endovascular repair (EVAR). The primary outcome was RFI defined by the RIFLE scale, studying Risk (1.5-fold increase in Cr or GFR decline >25% compared to baseline) and kidney injury (doubling of Cr or GFR decline >50%).

RESULTS

Seventy-five patients (OR=29, EVAR=46). Baseline characteristics for OR and EVAR were similar except for age (70.4 vs. 77.2 years; P<0.001), coronary artery disease (31% vs. 56.5%; P=0.04), neck length (12.3 vs. 22.7 mm; P=0.001) and baseline GFR (40.6 vs. 36.9 mL/min; P=0.03). There were no inter-group differences in postoperative RFI: Risk of RFI 13.8% OR vs. 13% EVAR and kidney Injury 6.9% vs. 0% (P=0.19). There were also no differences in RFI at one year. Comparing GFR and Cr after surgery and at 12 months to baseline values, the OR group presented a significant postoperative decline in GFR compared to EVAR group (-3.8% vs. 11.1%; P=0.03), which had recovered at one-year follow-up (16.6% vs. 9.5%; P=0.43), while EVAR group presented with a tendency toward increased Cr during follow-up (-9.2% vs. 2.2%; P=0.08). Multivariate analysis did not identify independent RFI prognostic factors.

CONCLUSIONS

Both techniques can be used safely in patients with CKD and baseline CKD is not a limiting factor for either technique. RFI is rare and transient in both groups.