Impact of chronic kidney disease on outcomes after abdominal aortic aneurysm repair

Chronic Kidney Disease is a Stronger Predictor for Mortality than Charlson Comorbidity Index after Abdominal Aortic Aneurysm Repair

BACKGROUND

Patients undergoing abdominal aortic aneurysm (AAA) repair face elevated mortality risk associated with advanced age and comorbidities, including chronic kidney disease (CKD). CKD alone demonstrates an increased risk for mortality in patients. Our cohort study aimed to identify whether CKD and/or comorbid burden using the Charlson Comorbidity Index (CCI) are potential contributors toward negative outcomes in patients who underwent AAA repair.

METHODS

We conducted a single-center retrospective cohort study on patients undergoing AAA repair between 2014 and 2024. The primary outcome is comorbidity burden (measured with CCI) and disease-specific burden (CKD measured by glomerular filtration rate (GFR)), as contributors to increased risk for mortality. Secondary outcomes included 30-day and mid-term complications and reinterventions after AAA repair. Propensity score matching was also conducted based on age, sex, hypertension, diabetes, smoking status, and coronary artery disease to assess for CKD and CCI burden.

RESULTS

A total of 212 matched patients underwent AAA repair, with 106 patients in the no CKD (GFR ≥60 mL/min) group and 106 in the CKD (GFR <60 mL/min) group. Sociodemographic variables, including age (no CKD: 75.29 ± 8.17 vs. CKD: 75.94 ± 8.80; P = 0.576), sex proportions (P = 0.846), and mean household income (no CKD: $99,199.08 ± 37,846.82 vs. CKD: $91,333.38 ± 32,128; P = 0.091), were similar between groups. Patients with CKD had significantly higher CCI scores (no CKD: 4.99 ± 1.96 vs. CKD: 6.11 ± 2.26; P < 0.001). Thirty-day complications (no CKD: 5.7% vs. CKD: 7.5%; P = 0.580) and aortic-related reintervention rates (no CKD: 13.2% vs. CKD: 12.3%; P = 0.837) were comparable between groups. Mortality was significantly higher in the CKD group (no CKD: 17.9% vs. CKD: 32.1%; P = 0.017). Logistic regression analysis demonstrated that stage 5 CKD (odds ratio (OR): 9.33, 95% confidence interval (CI): 1.26-97.09; P = 0.04), CKD (OR: 2.16 95% CI: 1.15-4.17; P = 0.018), and CCI score (OR: 1.42, 95% CI: 1.26-1.67; P < 0.001) are significantly associated with mortality.

CONCLUSION

Higher CCI and CKD stage are risk factors for a higher mortality rate in patients who underwent AAA repair. Subgroup analysis between CKD stages demonstrated that stage 5 has a stronger association with mortality than CCI. Strategies to decrease mid-term mortality rates might include enhanced preoperative optimization and individualized approach to care.

Kidney Function, Kidney Function Decline, and the Risk of Abdominal Aortic Aneurysm: The Stockholm CREAtinine Measurements (SCREAM) Project

OBJECTIVE

Low estimated glomerular filtration rate (eGFR) increases the risk of arterial diseases, possibly including abdominal aortic aneurysm (AAA). This study explored the relationship between eGFR (2008 CKD-EPI equation), annual eGFR decline, and subsequent risk of developing AAA in a large, community based sample.

METHODS

This was an observational study using complete healthcare records of Stockholm residents free from AAA who underwent routine creatinine testing during 2011 - 2021. Cox regression, adjusted for age, sex, comorbidities, and ongoing medications, was used to analyse the association between a single point eGFR or the change in eGFR within a year and the rate of both a de novo AAA diagnosis (both intact and ruptured) and fatal AAA (i.e., AAA followed by death within 30 days).

RESULTS

The study included 1 586 410 participants (mean age 48 years; 53% female; median eGFR 96 mL/min/1.73 m2). During a median follow up of 7.6 years, 5 313 participants (0.34%) experienced AAA, of which 321 (0.02%) were fatal. In multivariable analyses, compared with eGFR 90 mL/min/1.73 m2, the rates of AAA events were higher across lower eGFRs: for eGFR 30 mL/min/1.73 m2, the hazard ratio (HR) of AAA was 1.24 (95% confidence interval [CI] 1.09 - 1.40) and of fatal AAA was 2.51 (95% CI 1.67 - 3.75); for eGFR 15 mL/min/1.73 m2, the HR of AAA was 1.49 (95% CI 1.19 - 1.86) and of fatal AAA was 3.73 (95% CI 2.04 - 6.81). When analysed separately, the results were similar for intact and ruptured AAA risk. Among the 638 959 participants who had repeated eGFR tests, 3 447 (0.54%) experienced AAA events, of which 217 (0.04%) were fatal. Compared with stable eGFR (change -1 to 1 mL/min/year), the rate of AAA events was 15% higher (HR 1.15, 95% CI 1.05 - 1.26) in participants with an eGFR decline of 1 to 3 mL/min/year and 46% higher (HR 1.46, 95% CI 1.16 - 1.84) in those with an eGFR decline of > 3 mL/min/year.

CONCLUSION

In this observational study, both a single point eGFR and a faster eGFR decline were associated with the risk of experiencing AAA. The incidence of AAA, and particularly fatal AAA, was higher in individuals with greater severity of chronic kidney disease or faster eGFR decline.

Hospital Volume and Social Determinants of Health Do Not Impact Outcomes in Fenestrated Visceral Segment Endovascular Aortic Repair for Patients Treated at VQI Centers

ObjectiveThe purpose of this study is to investigate the impact of social determinants of health on access to high volume centers and clinical outcomes in fenestrated abdominal aortic endografting. Further, the effect of center volume in fenestrated endografting on outcomes will be sought as this is ill defined. The data herein have the potential to affect referral patterns and locations of complex fenestrated aortic aneurysm care. If lower volume centers achieve equivalent outcomes to higher volume centers, then limiting access to a small number of centers may not be justified.MethodsVascular Quality Initiative (VQI) was utilized as the data source. Four adverse outcomes categories were investigated : (1) Lack of follow up data in the VQI database at 1 year postoperatively; (2) Thirty day operative mortality; (3) Composite perioperative adverse event outcome; and (4) Twelve month mortality. Social determinants of health exposure variables included rural status, non-metropolitan living area, highest and lowest decile and quintile area deprivation index, insurance status, and non-home living status. Designated categories were created for patients operated on in centers within the top 25% of case volume, centers in the bottom 25% of case volume, and in centers with less than 10 total fenestrated endograft cases. Univariable analyses were performed with Chi-squared testing for categorical variables and t test for comparison of means. Multivariable binary logistic regression was performed to identify risks for the composite adverse perioperative event.ResultsThere was no statistically significant association with the composite adverse perioperative event category, 30-day mortality or 12-month mortality for any of the social determinants of health or center volume categories. Patients who live in rural areas (P = .029) and patients with Military/VA insurance (P < .001) were significantly more likely to be lost to follow up at their index VQI center at 1 year. When accounting for all standard co-morbidities, none of the following variables had any significant association with the composite adverse perioperative event on multivariable analysis: absolute center volume as an ordinal variable (P = .985); procedure at a bottom 25th percentile volume center (P = .214); procedure at a center with less than 10 total fenestrated cases in the database (P = .521); rural home status (P = .622); remote from metropolitan home status (P = .619); highest 10% ADI (P = .903); highest 20% ADI (P = .219); Lowest 10% of ADI (P = .397). The variables that had a statistically significant multivariable association with the composite adverse event were 3 or 4 visceral vessels stented vs 2 vessels (P < .001), baseline renal insufficiency (P < .001), female sex (P < .001), ESRD on dialysis (P = .002), and history of coronary revasculizaiton (P = .047). There was noted to be a statistically significant (P < .01) increase in 30 day mortality, composite adverse perioperative event, and 12 month mortality in moving from 2 to 3 to 4 fenestrated stented vessels. However, amongst patients who were treated with 3 and 4 vessel fenestrated stenting, patients treated at bottom 25th percentile centers and centers with less than 10 total cases did not experience a higher rate of composite adverse perioperative event, 30 day mortality, or 12 month mortality relative to top 25% volume centers indicating safety of these procedures in lower volume centers.ConclusionsSocial determinants of health and center volume do not impact outcomes in fenestrated visceral segment aortic endograft procedures performed at centers participating in the Vascular Quality Initiative. There is progressive morbidity and mortality in moving from 2 to 3 to 4 visceral stents and fenestrations, however lower volume centers within VQI achieve equivalent outcomes to high volume centers in performing 3 and 4 vessel visceral fenestrated stent cases. Female sex, ESRD, prior coronary revascularization, and baseline renal insufficiency portend an increased risk for perioperative morbidity for fenestrated visceral segment aortic endografting.

Predicting Short-Term Mortality after Endovascular Aortic Repair Using Machine Learning-Based Decision Tree Analysis

BACKGROUND

Endovascular aneurysm repair (EVAR) has revolutionized the treatment of abdominal aortic aneurysms by offering a less invasive alternative to open surgery. Understanding the factors that influence patient outcomes, particularly for high-risk patients, is crucial. The aim of this study was to determine whether machine learning (ML)-based decision tree analysis (DTA), a subset of artificial intelligence, could predict patient outcomes by identifying complex patterns in data.

METHODS

This study analyzed 169 patients who underwent EVAR to identify predictors of short-term mortality (within 3 years) using DTA. Data included 23 variables such as age, gender, nutritional status, comorbidities, and surgical details. The Python 3.7 was used as the programming language, and the scikit-learn toolkit was used to complete the derivation and verification of the decision tree classifier.

RESULTS

DTA identified poor nutritional status as the most significant predictor, followed by chronic kidney disease, chronic obstructive pulmonary disease, and advanced age (octogenarian). The decision tree identified 6 terminal nodes with a risk of short-term mortality ranging from 0% to 79.9%. This model had 68.7% accuracy, 65.7% specificity, and 79.0% sensitivity.

CONCLUSIONS

ML-based DTA is promising in predicting short-term mortality after EVAR, highlighting the need for comprehensive preoperative assessment and individualized management strategies.

Outcomes of Thoracic and Complex Endovascular Aortic Repair in Patients with Renal Insufficiency

BACKGROUND

Thoracic endovascular aortic repair (TEVAR) and complex endovascular aneurysm repair (cEVAR) are effective and minimally invasive treatment options for preventing rupture and decreasing mortality of aortic aneurysms. Patients with renal insufficiency are prone to worse postoperative cardiovascular morbidity and mortality due to the atherosclerosis burden as well as increased levels of angiotensin II. Nonetheless, knowledge about the outcomes of aortic stent graft therapy in patients with chronic kidney disease (CKD) or dialysis is scarce. This study aimed to examine outcomes after TEVAR and cEVAR in patients on CKD and dialysis.

METHODS

Utilizing data from the Vascular Quality Initiative (VQI) Vascular Implant Surveillance and Interventional Outcomes Network database, we retrospectively evaluated patients who underwent TEVAR or cEVRA from 2010 to 2018. Patients were divided into patients with no CKD or dialysis, CKD patients, and dialysis patients. Outcomes were in-hospital stroke, myocardial infarction (MI), spinal cord ischemia (SCI), 30-day mortality, 1-year mortality, aneurysmal rupture, and reintervention. In-hospital outcomes were assessed using multivariable logistic regression analysis and 1-year outcomes were evaluated using Kaplan-Meier Survival and Cox regression analyses.

RESULTS

A total of 4,867 patients were included in the study, 2,694 had no CKD or dialysis, 2,047 had CKD, and 126 were on dialysis. Dialysis patients were significantly younger, and more likely to be non-White and of Hispanic/Latino origin. They were also more likely to have medical comorbidities. CKD patients had higher odds of in-hospital MI (odds ratio [OR]: 2.02, 95% confidence interval [CI] (1.43-2.86), P < 0.001) and 30-day mortality (OR: 1.56, 95% CI (1.18-2.07), P < 0.001) compared to patients with no CKD or dialysis. Dialysis patients had higher odds of 30-day mortality (OR: 3.31, 95% CI (1.73-6.35), P < 0.001). At 1 year, dialysis was associated with a higher risk of mortality (hazard ratio [HR]: 3.48, 95% CI (2.39-5.07), P < 0.001) and reintervention (HR: 1.72, 95% CI (1.001-2.94), P < 0.049). CKD was associated with a higher risk of mortality (HR: 1.45, 95% CI (1.21-1.75), P < 0.001) compared to patients with no CKD or dialysis.

CONCLUSIONS

Among patients undergoing TEVAR or cEVAR, there was no significant difference in the risk of in-hospital stroke, SCI, and 1-year aneurysmal rupture among dialysis and CKD patients compared to patients with no CKD or dialysis. However, CKD patients had twice the risk of in-hospital MI. Dialysis patients had a higher risk of 1-year reintervention. Both dialysis and CKD patients had a higher risk of 30-day and 1-year mortality.

Hospital-level variation in costs of elective nonruptured abdominal aortic aneurysm repair

BACKGROUND

With the aging population in the United States, the incidence of abdominal aortic aneurysms is shifting to older ages. Given changing demographic characteristics and increasing health care expenditures, the present study evaluated the degree of center-level variation in the cost of elective abdominal aortic aneurysm repair.

METHODS

We identified all adult (≥18 years) hospitalizations for elective repair of nonruptured abdominal aortic aneurysms in the 2017 to 2020 Nationwide Readmissions Database. Hierarchical mixed-effects models were used to rank hospitals based on risk-adjusted costs. The interclass coefficient was used to calculate the amount of variation attributable to hospital-level characteristics. High-cost hospitals were classified as centers in the top decile of costs. The association of high-cost hospitals status with outcomes of interest was examined.

RESULTS

An estimated 62,626 patients underwent abdominal aortic aneurysm repair, and 5,011 (8.0%) were managed at high-cost hospitals. Compared with non-high-cost hospitals, high-cost hospitals were more commonly large (52.6% vs 48.3%) metropolitan (78.3% vs 66.9%) teaching centers (all P < .001). The interclass coefficient found that 28% of the observed variation in cost is attributable to hospital factors. After adjustment, high-cost hospitals were associated with increased odds of gastrointestinal (adjusted odds ratio = 1.42; 95% CI, 1.05-1.90) and infectious (adjusted odds ratio = 1.35; 95% CI, 1.14-1.59) complications. Finally, the Elixhauser index (β = +$2,700/unit; 95% CI, $2,500-$3,000) and open repair (β = +$4,100; 95% CI, $3,100-$5,200) were associated with increased costs.

CONCLUSION

We observed significant variation in cost attributable to center-level differences. Our findings have implications for reimbursement paradigms and the establishment of quality and cost benchmarks in the elective repair of abdominal aortic aneurysm.

Development of a comorbidity index for patients undergoing abdominal aortic aneurysm repair

BACKGROUND

Endovascular aneurysm repair (EVAR) and open surgical repair (OSR) are two modalities to treat patients with abdominal aortic aneurysm (AAA). Alternative to individual comorbidity adjustment, a summary comorbidity index is a weighted composite score of all comorbidities that can be used as standard metric to control for comorbidity burden in clinical studies. This study aimed to develop summary comorbidity indices for patients who underwent AAA repair.

METHODS

Patients who went under EVAR or OSR were identified in National Inpatient Sample (NIS) between the last quarter of 2015 to 2020. In each group, patients were randomly sampled into experimental (2/3) and validation (1/3) groups. The weights of Elixhauser comorbidities were determined from a multivariable logistic regression and single comorbidity indices were developed for EVAR and OAR groups, respectively.

RESULTS

There were 34,668 patients underwent EVAR (2.19% mortality) and 4792 underwent OSR (10.98% mortality). Both comorbidity indices had moderate discriminative power (EVAR c-statistic, 0.641; 95% confidence interval [CI], 0.616-0.665; OSR c-statistic, 0.600; 95% CI, 0.563-0.630) and good calibration (EVAR Brier score, 0.021; OSR Brier score, 0.096). The indices had significantly better discriminative power (DeLong P <.001) than the Elixhauser Comorbidity Index (ECI) (EVAR c-statistic, 0.572; 95% CI, 0.546-0.597; OSR c-statistic, 0.502; 95% CI, 0.472-0.533). For internal validation, both indices had similar performance compared with individual comorbidity adjustment (EVAR DeLong P = .650; OSR DeLong P = .431). These indices demonstrated good external validation, exhibiting comparable performance to their respective validation groups (EVAR DeLong P = .891; OSR DeLong P = .757).

CONCLUSIONS

ECI, the comorbidity index formulated for the general population, exhibited suboptimal performance in patients who underwent AAA repair. In response, we developed summary comorbidity indices for both EVAR and OSR for AAA repair, which were internally and externally validated. The EVAR and OSR comorbidity indices outperformed the ECI in discriminating in-hospital mortality rates. They can standardize comorbidity measurement for clinical studies in AAA repair, especially for studies with small samples such as single-institute data sources to facilitate replication and comparison of results across studies.

Cardiac risk after elective endovascular repair for infrarenal abdominal aortic aneurysm: Results from the Italian Collaborators for EVAR multicenter registry

OBJECTIVE

Major adverse cardiac events (MACEs) were common complications after endovascular aortic repair (EVAR) causing significant postoperative morbidity and mortality. The aim of the study was to evaluate the cardiac risk after elective EVAR for uncomplicated noninfected infrarenal abdominal aortic aneurysm in a large multicenter cohort.

METHODS

This is a multicenter, retrospective, financially unsupported physician-initiated observational cohort study conducted by four academic tertiary referral hospitals from January 2018 to March 2021. Baseline, perioperative, and postoperative information of elective EVARs was evaluated. The primary outcome was the incidence of MACEs after EVAR, which was defined as acute coronary syndrome, non-ST-elevation myocardial infarction, unstable angina pectoris, de novo atrial fibrillation, hospitalization for heart failure, and revascularization as well as cardiovascular death. Secondary outcomes were 1-year overall survival (all-cause mortality) and freedom from aorta-related mortality. Comparative analysis was conducted between MACE and overall population, and univariate and multivariate logistic regression analyses were used to analyze factors associated with the risk of the MACE occurrence and early 1-year mortality.

RESULTS

The study has enrolled 497 patients (35 females, 7%) with a mean age of 75.3 ± 7.8 years. The MACE rate was 6.4% (32/497, events/patients), and the majority of the events were recorded in the postoperative period (24/32, 75%; overall 24/497, 4.8%). One-year survival from all-cause mortality was 94% (95% confidence interval [CI]: 91-96), and the MACE population showed a significantly lower survival estimation rate (Overall - MACEs, 95.8% [95% CI: 93-97] - 67.9% [95% CI: 47-82], log-rank 41.950, P = .0001). Freedom from aorta-related mortality was 99.3% (95% CI: 98-100). The perioperative need for red blood cell transfusions was strongly related to the MACE occurrence (odds ratio: 2.67, 95% CI: 1.52-4.68, P = .001) and 1-year mortality (hazard ratio: 2.14, 95% CI: 1.48-3.09, P = .0001).

CONCLUSIONS

MACEs represent a common complication in the postoperative and early period after elective EVAR. Blood loss requiring red blood cell transfusions is associated with increased postoperative MACEs and early mortality, suggesting that all the efforts should be carried out to reduce the bleeding during and after elective interventions.

Impact of Physician Experience on Stroke or Death Rates in Transfemoral Carotid Artery Stenting: Insights from the Vascular Quality Initiative

Objective

With the recent expansion of the Centers for Medicare and Medicaid Services (CMS) coverage, transfemoral carotid artery stenting (tfCAS) is expected to play a larger role in the management of carotid disease. Existing research on the tfCAS learning curve, primarily conducted over a decade ago, may not adequately describe the current effect of physician experience on outcomes. This study evaluates the tfCAS learning curve using VQI data.

Methods

We analyzed tfCAS patient data from 2005-2023. Each physician's procedures were chronologically grouped into 12 categories, from procedure counts 1-25 to 351+. Primary outcome was in-hospital stroke/death rate; secondary outcomes were in-hospital stroke/death/MI, 30-day mortality, and in-hospital stroke/TIA. The relationship between outcomes and procedure counts was analyzed using Cochran Armitage test and a generalized linear model with restricted cubic splines, validated using generalized estimating equations.

Results

We analyzed 43,147 procedures by 2,476 physicians. In symptomatic patients, there was a decrease in rates of in-hospital stroke/death (procedure counts 1-25 to 351+: 5.2% to 1.7%), in-hospital stroke/death/MI (5.8% to 1.7%), 30-day mortality (4.6% to 2.8%), in-hospital stroke/TIA (5.0% to 1.1%) (all p-values<0.05). The in-hospital stroke/death rate remained above 4% until 235 procedures. Similarly, in asymptomatic patients, there was a decrease in rates of in-hospital stroke/death (2.1% to 1.6%), in-hospital stroke/death/MI (2.6% to 1.6%), 30-day mortality (1.7% to 0.4%), and in-hospital stroke/TIA (2.8% to 1.6%) with increasing physician experience (all p-values<0.05). The in-hospital stroke/death rate remained above 2% until 13 procedures.

Conclusions

In-hospital stroke/death and 30-day mortality rates post-tfCAS decreased with increasing physician experience, showing a lengthy learning curve consistent with previous reports. Given that physicians' early cases may not be included in the VQI, the learning curve was likely underestimated. With the recent CMS coverage expansion for tfCAS, a significant number of physicians would enter the early stage of the learning curve, potentially leading to increased post-operative complications.

Simplifying Hospital Quality Comparisons for Vascular Surgery Using Center-Level Frailty Burden Rather Than Comorbidities

BACKGROUND

Failure to rescue (FtR), or inpatient death following complication, is a publicly reported hospital quality measure. Previous work has demonstrated significant variation in the proportion of frail patients across hospitals. However, frailty is not incorporated into risk-adjustment algorithms for hospital quality comparisons and risk adjustment is made by comorbidity scores. Our aim was to assess the impact of frailty on FtR quality measurement and as a means of risk adjustment.

METHODS

Patients undergoing open or endovascular aneurysm repair or lower extremity bypass in the Vascular Quality Initiative (VQI) at centers performing ≥ 25 vascular procedures annually (2003-2019) were included. Multivariable logistic regression evaluated in-hospital death using scaled hierarchical modeling clustering at the center level. Center FtR observed/expected ratios were compared with expected values adjusted for either standard comorbidity profiles or frailty as measured by the VQI Risk Analysis Index. Centers were divided into quartiles using VQI-linked American Hospital Association data to describe the hospital characteristics of centers whose ranks changed.

RESULTS

A total of 63,143 patients (213 centers) were included; 1,630 patients (2.58%) were classified as FtR. After accounting for center-level variability, frailty was associated with FtR [scaled odds ratio 1.9 (1.8-2.0), P < 0.001]. The comorbidity-centric and frailty-based models performed similarly in predicting FtR with C-statistics of 0.85 (0.84-0.86) and 0.82 (0.82-0.84), respectively. Overall changes in ranking based on observed/expected ratios were not statistically significant (P = 0.48). High and low performing centers had similar ranking using comorbidity-centric and frailty-based methods; however, centers in the middle of the performance spectrum saw more variability in ranking alterations. Forty nine (23%) of hospitals improved their ranking by five or more positions when using frailty versus comorbidity risk adjustment. The centers in Quartile 4, those who performed the highest number of vascular procedures annually, experience on average a significant improvement in hospital ranking when frailty was used for risk adjustment, whereas centers performing the fewest number of vascular procedures and the lowest proportion of vascular surgery cases annually (Quartile 1) saw a significant worsening of ranking position (all P < 0.05). However, total number of surgical procedures annually, total hospital beds, for-profit status, and teaching hospital status were not significantly associated with changes in rank.

CONCLUSIONS

A simple frailty-adjusted model has similar predictive abilities as a comorbidity-focused model for predicting a common quality metric that influences reimbursement. In addition to distilling the risk-adjustment algorithm to a few variables, frailty can be assessed preoperatively to develop quality improvement efforts for rescuing frail patients. Centers treating a greater proportion of frail patients and those who perform higher volumes of vascular surgery benefit from a risk adjustment strategy based on frailty.

Dying to Get There: Patients Who Reside at Increased Distance from Tertiary Center Experience Increased Mortality Following Abdominal Aortic Aneurysm Rupture

BACKGROUND

Centralization of vascular surgery care for Ruptured Abdominal Aortic Aneurysms (RAAAs) to high-volume tertiary centers may hinder access to timely surgical intervention for patients in remote areas. The objective of this study was to determine the association between distance from vascular care and mortality from RAAAs in the province of Nova Scotia, Canada.

METHODS

A retrospective cohort study of all RAAAs in Nova Scotia between 2005 and 2015 was performed through linkage of administrative databases. Patients were divided into groups by estimated travel time from their place of residence to the tertiary center (<1 hr and ≥1 hr) using geographic information software. Baseline and operative characteristics were identified for all patients through available databases and completed through chart review. Mortality at home, during transfer to the vascular center, and overall 30-day mortality were compared between groups using t-test and chi-squared test, as appropriate. Multivariable logistic regression analysis was used to calculate the independent effect of travel time on survival outcomes.

RESULTS

A total of 567 patients with RAAA were identified from 2005-2015, of which 250 (44%) resided <1 hr travel time to the tertiary center and 317 (56%) resided ≥1 hr. On multivariable analysis, travel time ≥1 hr from vascular care was an independent predictor of mortality at home (odds ratio [OR] 1.68, 95% confidence interval [CI] 1.07-2.63, P = 0.02), mortality prior to operation (OR 2.64, 95% CI 1.81-3.83, P < 0.001), and overall 30-day mortality (OR 1.61, 95% CI 1.10-2.37, P = 0.02). In patients who received an operation (n = 294), there was no association between increased travel time and mortality (OR 1.02, 95% CI 0.60-1.73, P = 0.94).

CONCLUSIONS

Travel time ≥1 hr to the tertiary center is associated with significantly higher mortality from ruptured abdominal aortic aneurysm (AAA). However, there was no difference in overall chance of survival between groups for patients that underwent AAA repair. Therefore, strategies to facilitate early detection, and timely transfer to a vascular surgery center may improve outcomes for patients with RAAA.

Predicting Infection Related Complications After Endovascular Repair of Infective Native Aortic Aneurysms

OBJECTIVE

Endovascular aortic repair (EVAR) as surgical treatment for infective native aortic aneurysm (INAA) is associated with superior survival compared with open surgery, but with the risk of infection related complications (IRCs). This study aimed to assess the association between baseline clinical and computed tomography (CT) features and the risk of post-operative IRCs in patients treated with EVAR for INAA. It also sought to develop a model to predict long term IRCs in patients with abdominal INAA treated with EVAR.

METHODS

All initial clinical details and CT examinations of INAAs between 2005 and 2020 at a major referral hospital were reviewed retrospectively. The images were scrutinised according to aneurysm features, as well as peri-aortic and surrounding organ involvement. Data on post-operative IRCs were found in the patient records. Cox regression analysis was used to derive predictors for IRCs and develop a model to predict five year IRCs after EVAR in abdominal INAA.

RESULTS

Of 3 780 patients with the diagnosis of aortic aneurysm or aortitis, 98 (3%) patients were treated with EVAR for abdominal INAAs and were thus included. The mean follow up time was 52 months (range 0 ‒ 163). The mean transaxial diameter was 6.5 ± 2.4 cm (range 2.1 ‒14.7). In the enrolled patients, 38 (39%) presented with rupture. The five year IRC rate in abdominal INAAs was 26%. Female sex, renal insufficiency, positive blood culture, aneurysm diameter, and psoas muscle involvement were predictive of five year IRC in abdominal INAA after EVAR. The model had a C-index of 0.76 (95% CI 0.66 - 0.87).

CONCLUSION

Pre-operative clinical and CT features have the potential to predict IRC after endovascular aortic repair in INAA patients. These findings stress the importance of rigorous clinical, laboratory, and radiological follow up in these patients.

Chronic kidney disease impacts outcomes after abdominal aortic aneurysm repair

OBJECTIVE

Chronic kidney disease (CKD) and end-stage renal disease are traditionally associated with worse outcomes after endovascular and open repair of abdominal aortic aneurysm (AAA). This study stratifies outcomes of AAA repair by approach, CKD severity, and dialysis dependence.

METHODS

All patients undergoing elective infrarenal open aneurysm repair (OAR) and endovascular aortic repair (EVAR) with preoperative renal function data captured by the Vascular Quality Initiative between January 2003 and September 2020 were analyzed. Patients were stratified by CKD class as follows: CKD stages 1 and 2, CKD stage 3a, CKD stage 3b, CKD stages 4 and 5, and dialysis. Primary outcomes were perioperative and 1-year mortality. Predictors of survival were identified by Cox multivariate regression models.

RESULTS

In total, 53,867 elective AAA repairs were identified: 5396 (10%) OARs and 48,471 (90%) EVARs. Most patients were White (90%) and male (81%), with a mean age of 73 ± 9 years. Patients who underwent EVAR were older and had more comorbidities. The use of elective EVAR for AAA increased from 52% in 2003 to 91% in 2020 (P < .001). The OAR cohort had more perioperative complications and short-term mortality. The CKD 1 and 2 group had the highest 1-year survival compared with the other groups after both OAR and EVAR. On Cox regression analysis, after EVAR, compared with CKD 1 and 2, worsening CKD stage (CKD 3a: hazard ratio [HR], 1.25; 95% confidence interval [CI], 0.93-1.68; P = .13; CKD 3b: HR, 1.74; 95% CI, 1.23-2.45; P < .050; CKD 4-5: HR, 3.23; 95% CI, 2.13-4.88; P < .001), and dialysis (HR, 4.48; 95% CI, 1.90-10.6; P < .001) were independently associated with worse 1-year survival rates. After OAR, compared with CKD 1 and 2, worsening CKD stage (CKD 3a: HR, 1.08; 95% CI, 0.96-1.20; P = .20; CKD 3b: HR, 1.60; 95% CI, 1.41-1.81; P < .001; CKD 4-5: HR, 2.85; 95% CI, 2.39-3.41; P < .001), and dialysis (HR, 3.79; 95% CI, 3.01-4.76; P < .001) were independently associated with worse 1-year survival rates.

CONCLUSIONS

Regardless of the treatment approach, CKD severity is an important predictor of perioperative and 1-year mortality rates after infrarenal AAA repair and may reflect the natural history of CKD. Open repair is associated with high perioperative mortality risk in patients with CKD stages 4 and 5, as well as end-stage renal disease. Individualization of patient decision-making is especially important in patients with a glomerular filtration rate of less than 45 and perhaps consideration should be given to raising the threshold for elective AAA repair in these patients. Further studies focusing on appropriate size threshold for repair in these patients may be warranted.

Selection criterion for endovascular aortic repair in those with chronic kidney disease

OBJECTIVE

Endovascular aortic repair (EVAR) is the preferred method of repair for abdominal aortic aneurysms (AAAs). However, patients with advanced chronic kidney disease (CKD) are a high-risk group, and it is unknown which patients with CKD benefit from EVAR vs continued surveillance. The purpose of this study was to identify which patients with advanced CKD may benefit from EVAR.

METHODS

The Vascular Quality Initiative Database was utilized to identify elective EVARs for AAAs. Patients were excluded if they underwent urgent or emergent repairs. CKD stages were categorized based on preoperative estimated glomular filtration rate (eGFR) and dialysis status. Predicted 1-year mortality of untreated AAAs was calculated by modifying a validated comorbidity score that predicts 1-year mortality (Gagne Index) without repair. The primary outcome was actual 1-year mortality, which was compared with the predicted 1-year mortality without repair.

RESULTS

A total of 34,926 patient met study criteria. There were differences in Gagne Indices among the varying classes of CKD. Patients with CKD 4 and CKD 5 had the highest 1-year mortality rates, followed by CKD 3b, which was significantly higher than those with CKD 1 and CKD 2. Patients with CKD 4 had no differences between actual 1-year mortality with EVAR and predicted 1-year survival without EVAR across all AAA sizes. Those with CKD 5 had worse actual 1-year survival with EVAR than predicted 1-year survival without EVAR for AAAs <5.5 cm. Patients with CKD 5 only experienced an actual mortality benefit with EVAR compared with predicted 1-year mortality without EVAR for AAAs ≥7.0 cm.

CONCLUSION

The current data suggest that patients with CKD 3b, 4, and 5 represent a high-risk group who may not benefit from elective EVAR utilizing traditional size criteria. Patients with CKD 4 and 5 with AAAs <5.5 cm do not benefit from elective EVAR. In patients with CKD 5, elective EVAR may need to be reserved for AAAs ≥7.0 cm unless there are other concerning anatomic characteristics.

Open Abdominal Aortic Aneurysm Surgery and Renal Dysfunction; Association of Demographic and Clinical Variables with Proximal Clamp Location

BACKGROUND

While cross-clamp site is a known risk factor for postoperative acute and chronic renal dysfunction following open abdominal aortic aneurysm surgery (AAA), the additive impact of patient demographic and clinical factors is lacking. In this study, we investigated the impact of body mass index (BMI), surgical duration and aneurysm diameter on the association between proximal cross-clamp location and postoperative renal dysfunction.

METHODS

In this study, we conducted a retrospective analysis of 4,197 patients undergoing open AAA surgery between 2011 and 2018 using data housed in the American College of Surgeons National Safety Quality Improvement Program (ACS-NSQIP) database. The primary outcome was renal dysfunction, which was defined as patients requiring dialysis within 30 days or patients with ≥2 mg/dL rise in creatinine from baseline. We assessed the incidence of renal dysfunction with regard to clamp location and subsequently used multivariable logistic regression to assess clinical and demographic factors associated with renal dysfunction. We used a regression model to plot the association of BMI, surgical duration, and aneurysm diameter with an adjusted probability of postoperative acute and chronic renal dysfunction for individual cross-clamp locations.

RESULTS

Of the 4,197 patients analyzed, 405 patients (9.6%) developed renal dysfunction within 30 days with 287 patients requiring dialysis. Patients with supraceliac clamp location had the highest incidence of renal dysfunction (20.4%). Our data showed a significant association of renal dysfunction with higher BMI patients [OR 1.04 (1.02, 1.07), P = 0.001], longer operative times [OR1.01 (1.01, 1.02), P < 0.001], clamp location between the superior mesenteric artery (SMA) and renal artery [OR 1.80 (1.17, 2.78), P = 0.007] and supraceliac clamp location [OR 2.47 (1.62, 3.76), P < 0.001].

CONCLUSIONS

The incidence of renal dysfunction increases with suprarenal clamps. Patients with higher BMI, longer operative times, and increasing aneurysm diameter, and a suprarenal clamp have a significantly increased risk of renal dysfunction compared to those who also had a suprarenal clamp but lower BMI, shorter operative times and smaller aneurysm diameter.

Failure to Preserve the Internal Iliac Artery During Abdominal Aortic Aneurysm Repair is Associated with Mortality and Ischemic Complications

OBJECTIVE

Open or endovascular repair of abdominal aortic aneurysms may involve the sacrifice of the internal iliac artery. The effect of internal iliac artery exclusion on ischemic complications and overall mortality was investigated.

METHODS

Data of 326 patients who underwent elective open surgical or endovascular treatment for a non-ruptured abdominal aortic aneurysm between January 2010 and December 2019 in a tertiary hospital were retrospectively reviewed. Ischemic complications included buttock claudication and spinal ischemia, including paraparesis, ischemic colitis, lower limb paresthesia, and skin necrosis. Their duration and mortality during this period were investigated.

RESULTS

Nearly 50% of patients (148; 45.4%) underwent endovascular aortic repair and 178 (54.6%) underwent open surgery. The median patient age was 78.00 years (range: 31-94 years). The median follow-up period was 1,140 days (range: 0-4,757 days). A total of 50 patients (15.3%) died during follow-up. Bilateral internal iliac arteries were preserved in 187 patients (57.4%); a single internal iliac artery was preserved in 86 patients (26.4%), and no internal iliac artery was preserved in 53 patients (16.3%). Ischemic complications occurred in 57 patients (17.5%). According to the multivariable analysis, failure to preserve bilateral internal iliac arteries (hazard ratio: 8.65, 95% confidence interval: 4.31-17.36, p<0.01), management of the internal iliac artery (hazard ratio: 3.05, 95% confidence interval: 2.17-4.28, p<0.01), and hyperlipidemia (hazard ratio: 2.09, 95% confidence interval: 1.04-4.17, p=0.04) affected ischemic complications. Further, according to the univariable analysis, patients experienced more ischemic complications when a single (hazard ratio: 6.97; 95% confidence interval: 3.74-13.02; p<0.01) or none of the internal iliac arteries were preserved (hazard ratio: 8.88; 95% confidence interval: 4.12-19.16; p<0.01) than when both internal iliac arteries were preserved. Moreover, according to the multivariable analysis, stage 5 chronic kidney disease (hazard ratio: 2.7, 95% confidence interval: 1.09-6.14, p=0.03), age > 75 years (hazard ratio: 2.48, 95% confidence interval: 1.12-5.49, p=0.03), cerebrovascular accident (hazard ratio: 1.95, 95% confidence interval: 1.00-3.78, p=0.05), and failure to preserve bilateral internal iliac arteries (hazard ratio: 1.91, 95% confidence interval: 1.02-3.46, p=0.04) were associated with higher mortality rates following abdominal aortic aneurysm repair.

CONCLUSIONS

Internal iliac artery exclusion is a risk factor for ischemic complications and overall mortality. Regarding abdominal aortic aneurysm repair, preservation of the internal iliac artery as much as possible is recommended.

Incidence and Risk Factors for Sac Expansion after Endovascular Aneurysm Repair of Abdominal Aortic Aneurysms

Purpose

This study aimed to examine the sac changes after endovascular aneurysm repair (EVAR) in patients with abdominal aortic aneurysms.

Methods

Materials and We examined the aneurysm sac size initially and regularly after surgery in 157 consecutive patients who underwent EVAR in 2009-2019. Contrast-enhanced computed tomography (CT) scans were used as well as ultrasound images with non-enhanced CT scans in the patients with renal insufficiency. Sac expansion (SE) at 3 years was divided into two categories: progressive SE (PSE) defined as continuous sac enlargement of ≥5 mm on serial follow-up images at 1 and 3 years compared with the initial sac and delayed SE (DSE) defined as re-expansion of ≥5 mm compared with the regressed or stable sac at 1 year. The SE rate at 1 and 3 years and the risk factors for SE at 3 years were analyzed using logistic regression.

Results

During a median follow-up of 32.5 months, nine reinterventions in six patients were performed with open conversion (n=5) and endovascular repair (n=4). At 1 year, 112 patients underwent follow-up imaging. SE and sac regression were noted in 4 (3.6%) and 57 (50.9%) patients, respectively. Of the 64 patients with 3-year follow-up images, 16 (25%) exhibited SE (PSE [n=6] and DSE [n=10]). In the multivariable analysis, the risk factors for overall SE at 3 years were endoleaks at 1 year (P=0.006) and renal insufficiency (P=0.003).

Conclusion

During post-EVAR follow-up, patients with any endoleak at 1 year or renal insufficiency must be strictly monitored for SE development.

Outcomes after endovascular reintervention for aortic interventions

OBJECTIVE

Endovascular reinterventions are often performed after previous open or endovascular aortic procedures. We used the GREAT (Global Registry for Endovascular Aortic Treatment) database to compare the outcomes between these groups. We also compared reintervention of any type with a group of patients who had undergone primary endovascular abdominal aortic aneurysm repair (EVAR).

METHODS

All patients enrolled in GREAT were grouped according to a previous EVAR or open abdominal aortic procedure (OAP). Univariate analysis was performed using the χ², Wilcoxon rank sum, and Fisher exact tests. Cox proportional analysis was used to test the predictors for all-cause and aorta-related mortality.

RESULTS

A total of 3974 subjects who had undergone EVAR with follow-up data available were included in the GREAT. Of the 3974 procedures, 196 (4.9%) were reinterventions (49 after OAP and 147 after previous EVAR). Reintervention after previous EVAR showed a trend toward a greater endoleak rate through 2 years (13.6% vs 4.1%; P = .07), although no difference was found in the occurrence of the intervention (12.2% vs 17.7%; P = .37). Reintervention after OAP resulted in higher all-cause mortality through 2 years of follow-up (32.7% vs 17.7%; P = .0.03). The predictors of mortality included prior OAP, renal insufficiency, and the use of cutdown for access. Compared with the patients who had undergone primary endovascular repair, patients in the reintervention cohort were older (75.3 years vs 73.3 years; P = .0005), had had only femoral artery access used (95.8% vs 90.3%; P < .0001), and were more likely to have undergone aortic branch vessel procedures (32.3% vs 13.3%; P < .0001). Both all-cause and aorta-related mortality through 2 years was higher in the reintervention group than in the primary EVAR group (21.4% vs 12.5% [P = .0003; and 4.6% vs 1% [P < .0001], respectively). On multivariate analysis, the predictors of aortic-related mortality included reintervention, renal insufficiency, chronic obstructive pulmonary disease, underweight body mass index, increasing aortic diameter, and the use of brachial artery or other arterial access sites.

CONCLUSIONS

Endovascular reintervention for aortic pathology was associated with higher mortality than was primary EVAR. Reinterventions after prior OAPs were associated with higher mortality than were prior EVARs.

Early outcomes of the t-Branch off-the-shelf multi-branched stent graft in 542 patients for elective and urgent aortic pathologies - a retrospective observational study

OBJECTIVE

The t-Branch, a standardized off-the-shelf multi-branched stent graft has been used for the treatment of elective and urgent cases in aortic disease. The aim of this study was to assess the early outcomes in terms of technical success, mortality, and morbidity in >500 patients being treated with the t-Branch device.

METHODS

A two-center retrospective observational study was undertaken including patients treated using the t-Branch (Cook Medical, Bloomington, IN) in elective or urgent settings for complex abdominal aortic aneurysm and thoraco-abdominal aortic aneurysm between 2014 and 2019 (early experience 2014-2016; late experience 2017-2019). Primary endpoints were technical success and early (30-day) mortality, and secondary endpoints were early morbidity, endoleak, and target vessel patency rates. Multivariable regression models were used to determine the independent association of risk factors with (1) mortality and (2) spinal cord ischemia.

RESULTS

A total of 542 patients (mean age, 70.5 ± 8.5 years; 388 men [72%]; mean aneurysm diameter, 7.5 ± 2.5 cm) were included (63% elective; 90% thoraco-abdominal aortic aneurysm). The technical success rate was 97% (526/542) (elective, 96.7% [328/339] vs urgent, 97.6% [208/213]). The total 30-day mortality rate was 12.3% (8.5% in elective, 15% in symptomatic, and 30% in contained rupture). After multivariate regression analysis, the mortality rate was associated with older age (odds ratio [OR], 1.07; 95% confidence interval [CI], 1.03-1.11; P < .001) and with lower baseline glomerular filtration rate (OR, 0.98; 95% CI, 0.98-0.99; P < .001). In elective cases, the mortality rate was associated with a history of coronary artery disease (OR, 0.26; 95% CI, 0.09-0.73; P < .011) and higher body mass index (OR, 0.87; 95% CI, 0.77-0.98; P < .027). In urgent cases, the mortality rate was associated with older age, (OR, 1.07; 95% CI, 1.02-1.13; P < .010) and lower baseline glomerular filtration rate (OR, 0.97; 95% CI, 0.95-0.99; P < .001). The spinal cord ischemia rate was 10.5% (6.5% temporary, 4% permanent) and was associated with the early study period (OR, 2.01; 95% CI, 1.03-3.89; P < .038). The renal impairment rate was 13%, the stroke rate was 2.5%, and the myocardial infarction rate was 1.8%, whereas the access complications rate was 7.7%. On early computed tomography angiography, the primary patency rate for the right renal artery was 99.6%, for the left renal artery was 100%, for the superior mesenteric artery was 99.4%, and for the coeliac trunk was 99.8%. The endoleak I and III rates were 2.7% (15/542) and 2.7% (15/542), respectively.

CONCLUSIONS

Elective and urgent use of the t-Branch multi-branched off-the shelf stent graft showed high technical success and early target vessel patency rates. Early mortality and morbidity rates were acceptable.

Impact of Chronic Kidney Disease on Aortic Disease-related Mortality: A Four-year Community-Based Cohort Study

Objective Despite advances in medicine, aortic diseases (ADs), such as aneurysm rupture and aortic dissection, remain fatal and carry extremely high mortality rates. Due to its low frequency, the risk of developing AD has not yet been fully elucidated. Chronic kidney disease (CKD) is an established risk factor for cardiovascular disease and mortality. The aim of the present study was to examine whether or not CKD is a risk for AD-related mortality in the general population. Methods We used a nationwide database of 554,442 subjects (40-75 years old) who participated in the annual "Specific Health Check and Guidance in Japan" checkup between 2008 and 2013. Results There were 131 aortic aneurysm and dissection deaths during the follow-up period of 2,123,512 person-years. A Kaplan-Meier analysis revealed that subjects with CKD had a higher rate of AD-related deaths than those without it. A multivariate Cox proportional hazard regression analysis demonstrated that CKD was an independent risk factor for AD-related death in the general population after adjusting for cardiovascular risk factors. The addition of CKD to cardiovascular risk factors significantly improved the C, net reclassification, and integrated discrimination indexes. Conclusion CKD is an additional risk for AD-related death, suggesting that CKD may be a target for the prevention and early identification of subjects at high risk for AD-related death in the general population.

Effect of renal function on patient survival after endovascular thoracoabdominal and pararenal aortic aneurysm repair

BACKGROUND

Renal dysfunction can be a prohibitive risk for open repair of complex thoracoabdominal aortic aneurysms (TAAAs) and pararenal aortic aneurysms (PRAAs). However, the effect of renal dysfunction from fenestrated and branched endovascular aneurysm repair (FB-EVAR) on outcomes is poorly defined. Our objective was to review the association of renal function on patient survival after FB-EVAR.

METHODS

The present study reviewed the clinical data of consecutive patients enrolled in a prospective nonrandomized study to investigate FB-EVAR for PRAAs and TAAAs at a single institution with 1 year of follow-up (2013-2017). The patients were categorized by preoperative chronic kidney disease (CKD) classification, and the early- and long-term mortality was assessed.

RESULTS

During the study period, 231 patients had undergone FB-EVAR for 80 PRAAs, 89 type I-III TAAAs, and 62 type IV TAAAs. The mean age was 74.6 ± 6.7 years, and 71% were men. Of the 231 patients, 126 had had CKD stage 1-2, 96 CKD stage 3, and 9 CKD stage 4-5 (all with baseline creatinine >2.0 mg/dL). Patients with CKD stage 4-5 had demographic data similar to those with normal renal function but had had slightly larger aneurysms (6.5 vs 7 cm; P = .15). The 30-day mortality was 0.5% (n = 1) for those with CKD 1-3 vs 0% for those with CKD 4-5 (P = .73). The 1- and 3-year survival analysis showed no major hazards (95% vs 88% and 84% vs 75%, respectively; log-rank P = .98) between the CKD 1-3 and CKD 4-5 groups. The median follow-up period was 2.6 years (interquartile range, 1.5-3.7 years). Two patients with CKD 4-5 had died during the follow-up period.

CONCLUSIONS

Although a small sample size for evaluation, selected patients with CKD 4-5 might have similar short- and long-term mortality compared with those with normal to moderate renal dysfunction after FB-EVAR. Although a major contraindication for open repair, renal dysfunction might not be as prohibitive for endovascular repair in well-selected patients.

Late outcomes of endovascular aortic stent graft therapy in patients with chronic kidney disease

Endovascular aneurysm repair (EVAR) and thoracic endovascular aortic repair (TEVAR) are effective and minimally invasive treatment options for high-risk surgical candidates. Nevertheless, knowledge about the management of aortic stent graft therapy in chronic kidney disease (CKD) is scarce. This study aimed to examine outcomes after EVAR and TEVAR in patients with CKD.Utilizing data from the Taiwan National Health Insurance Research Database, we retrospectively assessed patients who underwent EVAR and TEVAR therapy between January 1, 2006, and December 31, 2013. Patients were divided into CKD and non-CKD groups. Outcomes were in-hospital mortality, all-cause mortality, readmission, heart failure, and major adverse cardiac and cerebrovascular events.There were 1019 patients in either group after matching. The CKD group had a higher in-hospital mortality rate than the non-CKD group (15.2% vs 8.3%, respectively; odds ratio, 1.92; 95% confidence interval [CI], 1.46-2.54). Patients with CKD had higher risks of all-cause mortality including in-hospital death (46.1% vs 33.1%; hazard ratio [HR], 1.61; 95% CI, 1.35-1.92), readmission rate (62.6% vs 55.0%; subdistribution HR [SHR], 1.61; 95% CI, 1.32-1.69), redo stent (7.8% vs 6.2%; SHR, 1.50; 95% CI, 1.09-2.07), and major adverse cardiac and cerebrovascular events (13.3% vs 8.8%; SHR, 1.50; 95% CI, 1.15-1.95). The subgroup analysis did not demonstrate a variation in mortality between the TEVAR and EVAR cohorts (P for interaction = .725). The dialysis group had higher risks of all-cause mortality and readmission than the CKD without dialysis and non-CKD groups.Among EVAR/TEVAR recipients, CKD was independently associated with higher in-hospital mortality, postoperative complication, and all-cause mortality rates. Patients with end-stage renal disease on dialysis had worse outcomes than those in the CKD non-dialysis and non-CKD groups.

Thirty-day outcomes of open abdominal aortic aneurysm repair by proximal clamp level in patients with normal and impaired renal function

OBJECTIVE

Open surgical repair (OSR) of abdominal aortic aneurysms (AAAs) has often been reserved in contemporary practice for complex aneurysms requiring a suprarenal or supraceliac proximal clamp level. The present study investigated the associated 30-day outcomes of different proximal clamp levels in OSR of complex infrarenal/juxtarenal AAA in patients with normal renal function and those with chronic renal insufficiency (CRI).

METHODS

All patients undergoing elective OSR of infrarenal and juxtarenal AAA were identified in the American College of Surgeons National Surgical Quality Improvement Program-targeted AAA database from 2012 to 2018. The patients were stratified into two cohorts (normal renal function [estimated glomerular filtration rate, ≥60 mL/min] and CRI [estimated glomerular filtration rate, <60 mL/min and no dialysis]) before further substratification into groups by the proximal clamp level (infrarenal, inter-renal, suprarenal, and supraceliac). The 30-day outcomes, including mortality, renal and pulmonary complications, and major adverse cardiovascular event rates, were compared within each renal function cohort between proximal clamp level groups using the infrarenal clamp group as the reference. Supraceliac clamping was also compared with suprarenal clamping.

RESULTS

A total of 1284 patients with normal renal function and 524 with CRI were included in the present study. The proximal clamp levels for the 1808 patients were infrarenal for 1080 (59.7%), inter-renal for 337 (18.6%), suprarenal for 279 (15.4%), and supraceliac for 112 (6.2%). In the normal renal function cohort, no difference was found in 30-day mortality with any clamp level. Increased 30-day acute renal failure was only observed in the supraceliac vs infrarenal clamp level comparison (5.9% vs 1.5%; adjusted odds ratio [aOR], 3.97; 95% confidence interval [CI], 1.04-5.18; P = .044). In the CRI cohort, supraceliac clamping was associated with an increased rate of renal composite complications (22.7% vs 5.6%; aOR, 8.81; 95% CI, 3.17-24.46; P < .001) and ischemic colitis (13.6% vs 3.0%; aOR, 4.78; 95% CI, 1.38-16.62; P = .014) compared with infrarenal clamping and greater 30-day mortality (13.6% vs 2.4%; aOR, 6.00; 95% CI, 1.14-31.55; P = .034) and renal composite complications (22.7% vs 10.8%; aOR, 2.87; 95% CI, 1.02-8.13; P = .047) compared with suprarenal clamping. Suprarenal clamping was associated with greater renal dysfunction (10.8% vs 5.6%; aOR, 2.77; 95% CI, 1.08-7.13; P = .035) compared with infrarenal clamping, with no differences in mortality. No differences were found in 30-day mortality or morbidity for inter-renal clamping compared with infrarenal clamping in either cohort. No differences were found in major adverse cardiovascular events with higher clamp levels in either cohort.

CONCLUSIONS

In elective OSR of infrarenal and juxtarenal AAAs for patients with CRI, this study found a heightened mortality risk with supraceliac clamping and increased renal morbidity with suprarenal clamping, though these effects were not present for patients with normal renal function. Every effort should be made to keep the proximal clamp level as low as possible, especially in patients with CRI.

Peroperative Intravascular Ultrasound for Endovascular Aneurysm Repair versus Peroperative Angiography: A Pilot Study in Fit Patients with Favorable Anatomy

BACKGROUND

The aim of this study was to compare intravascular ultrasound (IVUS) assistance for endovascular aortic aneurysm repair (EVAR) to standard assistance by angiography.

METHODS

From June 2015 to June 2017, 173 consecutive patients underwent EVAR. In this group, 69 procedures were IVUS-assisted with X-ray exposure limited to completion angiography for safety purposes because an IVUS probe does not yet incorporate a duplex probe (group A), and 104 were angiography-assisted procedures (group B). All IVUS-assisted procedures were performed by vascular surgeons with basic duplex ultrasound (DUS) training. The primary study endpoints were mean radiation dose, duration of fluoroscopy, amount of contrast media administered, procedure-related outcomes, and renal clearance expressed as the glomerular filtration rate (GFR) before and after the procedure. Secondary endpoints were operative mortality, morbidity, and arterial access complications.

RESULTS

Mean duration of fluoroscopy time was significantly lower for IVUS-assisted procedures (24 ± 15 min vs. 40 ± 30 min for angiography-assisted procedures, P < 0.01). Moreover, mean radiation dose (Air KERMA) was significantly lower in IVUS-assisted procedures (76m Gy [44-102] vs. 131 mGy [58-494]), P < 0.01. IVUS-assisted procedures required fewer contrast media than standard angiography-assisted procedures (60 ± 20 mL vs. 120 ± 40 mL, P < 0.01). The mean duration of the procedure was comparable in the two groups (120 ± 30 min vs. 140 ± 30 min, P = 0.07). No difference in renal clearance before and after the procedure was observed in either of the two groups (99.0 ± 4/97.8 ± 2 mL/min in group A and 98.0 ± 3/97.6 ± 5 mL/min in group B) (P = 0.28). The mean length of follow-up was nine months (6-30 months). No postoperative mortality, morbidity, or arterial access complications occurred. No type 1 endoleak was observed. Early type II endoleaks were observed in 21 patients (11%), 12 in the angiography-assisted group (11%) and nine in the IVUS-assisted group (12%). They were not associated with sac enlargement ≥5 mm diameter and therefore did not require any additional treatment.

CONCLUSIONS

Compared with standard angiography-assisted EVAR, IVUS significantly reduces renal load with contrast media, fluoroscopy time, and radiation dose while preserving endograft deployment efficiency. Confirmation from a large prospective study with improved IVUS probes will be required before IVUS-assisted EVAR alone can become standard practice.

The removal of all proximal aneurysmal aortic tissue does not affect anastomotic degeneration after open juxtarenal aortic aneurysm repair

OBJECTIVE

For the open treatment of juxtarenal aortic aneurysms (JRAAs), some argue for the removal of all proximal aneurysmal aortic tissue to prevent future degeneration, whereas others deem it unnecessary. This study sought to compare perioperative and long-term outcomes of two different approaches to treatment of JRAAs.

METHODS

Patients who underwent open JRAA repair from 2007 to 2015 at our institution were reviewed and stratified by operative technique: plication of the aneurysm cuff with graft sewn up to the renal arteries (PLI) vs a beveled anastomosis with left renal artery bypass (LRB). Patients who underwent additional mesenteric bypasses were excluded. Primary outcomes included death, anastomotic degeneration, and decline in renal function. Univariate and Kaplan-Meier analyses were performed.

RESULTS

There were 199 patients identified, 56% PLI (n = 112) and 44% LRB (n = 87). The majority were male (68%), white (89%), and smokers (58%). Mean age was 71.5 ± 8.5 years. LRB patients were more likely to have chronic kidney disease (29% vs 13%; P = .01) and larger juxtarenal diameters (median, 25 mm vs 28 mm; P = .001). LRB patients had longer postoperative length of stay (median, 8 days vs 7 days; P = .003) and longer operative times (median, 4.7 hours vs 3.7 hours; P < .001). Overall 30-day mortality was 2% (n = 4), with no difference between cohorts. There were no differences in perioperative complications except for the development of acute kidney injury, which was more common in LRB patients (47% vs 23%; P < .001). During 3-year follow-up, there was no difference in anastomotic aneurysmal degeneration or sac growth. In the long term, LRB patients were more likely to develop an occluded left renal artery (20% vs 0%; P = .004) and right renal artery stenosis (29% vs 3%; P = .002). However, neither group was more likely to have a decline in renal function (PLI, 23%; LRB, 25%; P = .84). There was no difference in 5-year mortality (P = .72).

CONCLUSIONS

The more complex technique involving LRB was not protective against long-term anastomotic degeneration, decline in renal function, or mortality. In addition, LRB led to longer length of stay and operative times, with increased risk of perioperative acute kidney injury. In an era when fewer open aortic repairs are being performed, it is reasonable to consider the PLI technique in the treatment of JRAAs, particularly in patients with baseline chronic kidney disease.

National Study of Index and Readmission Mortality and Costs for Thoracic Endovascular Aortic Repair in Patients With Renal Disease

BACKGROUND

In the current era of value-based health care delivery, an understanding of patient populations at greatest risk for mortality, complications, and readmissions after thoracic endovascular aortic repair (TEVAR) is warranted. Thus, the present study aimed to evaluate outcomes after TEVAR for patients with varying degrees of renal dysfunction.

METHODS

All patients who underwent TEVAR from 2010 to 2015 in the Nationwide Readmissions Database were identified. These patients were further stratified into four groups: no chronic kidney disease (NCKD), chronic kidney disease (CKD) stages 1 to 3 (CKD1-3), CKD 4 to 5 (CKD4-5), and end-stage renal disease (ESRD) requiring dialysis. Multivariable regression analysis was used to study index mortality, early (30 days) and intermediate (31-90 days) readmissions, costs, and length of stay. Kaplan-Meier analyses were performed to compare readmission performance among all four groups.

RESULTS

An estimated 121,046 patients underwent TEVAR with 26,653 (22.1%) being elective. Patients with ESRD comprised 2.7% of elective and 5.4% of nonelective TEVAR operations. Patients with CKD4-5 (17.8%; P = .01) and with ESRD (21.1%; P < .001), but not with CKD1-3 (14.1%; P = .12), had remarkably higher early readmission rate than the NCKD cohort (9.2%). Patients with ESRD had remarkably higher hospitalization costs than the NCKD group ($7456; 95% confidence interval, $2629-$12,283). Cardiovascular, infectious, and vascular complications were the most prevalent diagnoses on readmission, with no remarkable difference among the NCKD and CKD4-5/ESRD groups.

CONCLUSIONS

Nearly 10% of all patients with TEVAR have evidence of chronic kidney disease of varying severity. Only patients with ESRD are at risk of substantially higher odds of mortality, readmissions, index length of stay, and costs compared with the non-CKD cohort.

Variation in center-level frailty burden and the impact of frailty on long-term survival in patients undergoing elective repair for abdominal aortic aneurysms

OBJECTIVE

Frailty is increasingly recognized as a key determinant in predicting postoperative outcomes. Centers that see more frail patients may not be captured in risk adjustment, potentially accounting for poorer outcomes in hospital comparisons. We aimed to (1) determine the effect of frailty on long-term mortality in patients undergoing elective abdominal aortic aneurysm (AAA) repair and (2) evaluate the variability in frailty burden among centers in the Vascular Quality Initiative (VQI) database.

METHODS

Patients undergoing elective open and endovascular AAA repair (2003-2017) were identified, and those with complete data on component variables of the VQI-derived Risk Analysis Index (VQI-RAI) and centers with ≥10 AAA repairs were included. VQI-RAI characteristics are sex, age, body mass index, renal failure, congestive heart failure, dyspnea, preoperative ambulation, and functional status. Frailty was defined as VQI-RAI ≥35 based on prior work in surgical patients using other quality improvement databases. This corresponds to the top 12% of patients at risk in the VQI. Center-level VQI-RAI differences were assessed by analysis of variance test. Relationships between frailty and survival were compared by Kaplan-Meier analysis and the log-rank test for open and endovascular procedures. Multivariable hierarchical Cox proportional hazards regression models were calculated with random intercepts for center, controlling for frailty, race, insurance, AAA diameter, procedure type, AAA case mix, and year.

RESULTS

A total of 15,803 patients from 185 centers were included. Mean VQI-RAI scores were 27.6 (standard deviation, 5.9; range, 4-56) and varied significantly across centers (F = 2.41, P < .001). The percentage of frail patients per center ranged from 0% to 40.0%. In multivariable analysis, frailty was independently associated with long-term mortality (hazard ratio, 2.88; 95% confidence interval, 2.6-3.2) after accounting for covariates and center-level variance. Open AAA repair was not associated with long-term mortality after adjusting for frailty (hazard ratio, 0.98; 95% confidence interval, 0.86-1.13). There was a statistically significant difference in the percentage of frail patients compared with nonfrail patients who were discharged to a rehabilitation facility or nursing home after both open (40.5% vs 17.8%; P < .0001) and endovascular repair (17.7% vs 4.6%; P < .0001).

CONCLUSIONS

There is considerable variability of preoperative frailty among VQI centers performing elective AAA repair. Adjusting for center-level variation, frailty but not procedure type had a significant association with long-term mortality; however, frailty and procedure type were both associated with nonhome discharge. Routine measurement of frailty preoperatively by centers to identify high-risk patients may help mitigate procedural and long-term outcomes and improve shared decision-making regarding AAA repair.

Outcomes after thoracic endovascular aortic repair in patients with chronic kidney disease in the Medicare population

OBJECTIVE

Thoracic endovascular aortic repair has been increasingly performed in higher-risk patients with renal failure. The objective was to compare Medicare patients with preoperative chronic kidney disease with patients with normal renal function to determine differences in postoperative survival and complications.

METHODS

From 2000 to 2014, 27,079 Medicare fee-for service patients underwent thoracic endovascular aortic repair. Patients were stratified by kidney function, and 23,375 patients (86%) had no chronic kidney disease, 2957 patients (11%) had chronic kidney disease stage I/IV, and 747 patients (3%) had end-stage renal disease or hemodialysis. Groups were then compared with determined differences in adjusted all-cause mortality and rates of postoperative complications.

RESULTS

Overall survival was significantly worse among patients with chronic kidney disease and end-stage renal disease or hemodialysis compared with patients with no chronic kidney disease (1-year survival no chronic kidney disease: 78%; chronic kidney disease I/II: 77%; chronic kidney disease III: 67%; chronic kidney disease IV: 58%; and end-stage renal disease or hemodialysis: 48%, P < .001). Mortality was significantly increased among patients with chronic kidney disease III (hazard ratio [HR], 1.29; P < .001), chronic kidney disease IV (HR, 1.74; P < .001), and end-stage renal disease or hemodialysis (HR, 2.03; P < .001). No mortality difference was found between patients with no chronic kidney disease and patients with chronic kidney disease stage I/II. At 30 days after thoracic endovascular aortic repair, sepsis was increased for patients with chronic kidney disease stage III/IV (HR, 1.7; P < .001) and end-stage renal disease or hemodialysis (HR, 2.7; P < .001).

CONCLUSIONS

In this elderly Medicare population undergoing thoracic endovascular aortic repair, patients with chronic kidney disease stage III, chronic kidney disease stage IV, or end-stage renal disease/hemodialysis had poor survival and increased morbidity compared with those with normal kidney function. These data may suggest that patients with chronic kidney disease stage III, chronic kidney disease stage IV, or end-stage renal disease/hemodialysis should be more cautiously evaluated for thoracic endovascular aortic repair, weighing the benefits of the procedure against the high expected mortality.

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.

Patients with end-stage renal disease have poor outcomes after endovascular abdominal aortic aneurysm repair

OBJECTIVE

Although endovascular repair of abdominal aortic aneurysms (AAAs) has been demonstrated to have favorable outcomes, not all cohorts of patients with AAA fare equally well. Our goal was to investigate perioperative and 1-year outcomes in patients with end-stage renal disease (ESRD) on dialysis, who have traditionally fared worse after vascular interventions, to assess how ESRD affects outcomes in a large modern cohort of endovascular aneurysm repair (EVAR) patients.

METHODS

The Vascular Quality Initiative database was queried for all patients undergoing EVAR from 2010 to 2017. ESRD patients were compared with patients not on dialysis. Propensity-matched scoring and multivariable analysis were used to isolate the effects of ESRD.

RESULTS

Of 28,683 EVARs identified, there were 321 (1.12%) patients with ESRD on dialysis. Patients with ESRD had no difference in presenting AAA size (57.5 ± 12.7 mm vs 56.7 ± 17.2 mm; P = .44); however, they had more urgent/emergent repairs (20.6% vs 13.6%; P = .002) than those without ESRD. ESRD patients were more often younger, nonwhite, and nonobese and less likely to have commercial insurance (P < .05). ESRD patients more often had hypertension, coronary artery disease, congestive heart failure, previous lower extremity bypass, aneurysm repair, and carotid interventions (P < .05). There was no difference in the rate of concomitant procedures. Matching based on demographics, comorbidities, and operative details showed that ESRD patients had longer hospital length of stay (4.8 ± 9.4 days vs 4.1 ± 12.6 days; P = .026) and higher 30-day mortality (7% vs 2.4%; P < .001). There was no difference in cardiac, pulmonary, lower extremity, bowel, and stroke complications or return to the operating room. On multivariable analysis, ESRD was associated with 30-day mortality (odds ratio, 4.1; 95% confidence interval, 2.6-6.7; P < .001). Of the 24,750 elective EVARs, 1.04% had ESRD on dialysis. Matched data for elective EVAR show increased postoperative length of stay, hospital mortality, and 30-day mortality for ESRD patients on dialysis compared with those who are not. There was no association with postoperative myocardial infarction or pulmonary complications. At 1 year, patients with ESRD on dialysis had worse survival (78% vs 94%; P < .001), and ESRD was associated with higher mortality (hazard ratio, 3.3; 95% confidence interval, 2.5-4.2; P < .001).

CONCLUSIONS

Among patients undergoing EVAR, ESRD is independently associated with higher perioperative and 1-year mortality despite not being associated with higher postoperative complications. This should be taken into account during informed consent for EVAR and risk-benefit considerations in this high-risk population, particularly for elective repair.

Volumetric Nephrogram Represents Renal Function and Complements Aortic Anatomic Severity Grade in Predicting EVAR Outcomes

INTRODUCTION

Chronic kidney disease (CKD) is a predictor of poor outcomes for patients undergoing endovascular aortic aneurysm repair (EVAR). Anatomic severity grade (ASG) represents a quantitative mechanism for assessing anatomical suitability for endovascular aortic repair. Anatomic severity grade has been correlated with repair outcomes and resource utilization. The purpose of this study was to identify a novel renal perfusion metric as a way to assist ASG with predicting EVAR outcomes.

METHODS

Retrospective review of a prospectively maintained database identified elective infrarenal aortic aneurysm repair cases. Anatomic grading was undertaken by independent reviewers. Using volumetric software, kidney volume, and a novel measure of kidney functional volume, the volumetric nephrogram (VN) was recorded. Systematic evaluation of the relationship of kidney volume and VN to CKD and ASG was undertaken using linear regression and receiver-operator statistical tools.

RESULTS

A total of 386 cases with patient and anatomic data were identified and graded. Mean age was 72.9 ± 0.4 years. Renal volume <281 mL correlated with CKD (area under the curve [AUC] = .708; P ≤ .0001). Volumetric nephrogram <22.5 HU·L correlated with CKD (AUC = 0.764; P ≤ .0001). High (≥15) ASG scores correlated with both renal volume (AUC = .628; P ≤ .0001) and VN (AUC = .628; P ≤ .0001). Regression analysis demonstrated a strong, inverse relationship between ASG and VN ( R² = .95).

CONCLUSION

These data demonstrate that VN is a strong predictor of CKD in a large database of patients undergoing elective aneurysm repair. We demonstrate an inverse relationship between renal function and ASG that has not been previously described in the literature. Additionally, we have shown that VN complements ASG as a model of overall cardiovascular health and atherosclerotic burden. Outcomes in patients with poor renal function may be related to anatomical issues in addition to well-described systemic ramifications.

Chronic Kidney Disease Class Predicts Mortality After Abdominal Aortic Aneurysm Repair in Propensity-matched Cohorts From the Medicare Population

INTRODUCTION

Chronic kidney disease (CKD) predicts mortality after abdominal aortic aneurysm (AAA) repair. Few studies are adequately powered to stratify outcomes by CKD severity. This study assesses the effect of CKD severity on survival after AAA repair.

METHODS

Patients who underwent AAA repair from 2006 to 2007 were retrospectively identified in the Medicare database and stratified by CKD class as follows: normal (CKD class 1 and 2), moderate (CKD class 3), and severe (CKD class 4 and 5). Propensity matching (30:1) by clinical factors and procedure type was performed to derive well-matched comparative cohorts. Primary outcomes were 30-day and long-term mortality; secondary outcomes included hospital length of stay and cost.

RESULTS

A total of 47,715 patients were included (96.7% normal, 1.88% moderate, and 1.65% severe). Propensity matching was corrected for differences between cohorts. Thirty-day mortality was higher in moderate (5.7% vs normal 2.5%; P < 0.01) and severe (9.9% vs normal 1.8%; P < 0.01) groups. Hospital length of stay increased with CKD severity (4.4 ± 3.7 days normal vs 6.5 ± 4.2 days moderate CKD; P < 0.01/4.7 ± 3.8 days normal vs 9.1 ± 4.5 days severe CKD; P < 0.01) as did cost ($23 ± 14K normal vs $25 ± 16K moderate; P < 0.01 /$22 ± 11K normal vs $29 ± 22K severe; P < 0.01). Three-year survival favored the normal cohort (80% vs 64% moderate; log rank P < 0.01 /82% normal vs 44% severe; log rank P < 0.01).

CONCLUSIONS

CKD severity is an important predictor of perioperative mortality and long-term survival after AAA repair in propensity-matched cohorts. The 5-fold increase in 30-day mortality and 44% in 3-year survival suggest that elective AAA repair is contraindicated in most severe CKD patients.

Concurrent renal artery stent during endovascular infrarenal aortic aneurysm repair confers higher risk for 30-day acute renal failure

OBJECTIVE

Concurrent renal artery angioplasty and stenting (RAAS) during endovascular aneurysm repair (EVAR) of infrarenal abdominal aortic aneurysm (AAA) has been practiced in an attempt to maintain renal perfusion. The aim of this study was to identify the current practice of RAAS during EVAR and its effect on perioperative renal outcome.

METHODS

Patients with infrarenal AAA were identified from the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP, 2011-2014) database. Baseline characteristics of patients with concurrent RAAS during EVAR were compared with those of patients who underwent EVAR only. Bivariate and multivariable logistic regression analyses controlling for patients' demographics, comorbidities, and operative factors were used to evaluate the predictors of 30-day acute renal failure (ARF). Sensitivity analysis was done to evaluate the role of RAAS in patients with prior kidney disease.

RESULTS

Overall, 6183 patients underwent EVAR for infrarenal AAA during the study period. Of them, 281 patients had RAAS during EVAR (4.5%). The median age of the patients was 74 years; 81.7% of the cohort was male, but a higher proportion of female patients received EVAR + RAAS compared with patients who underwent EVAR only (26.3% vs 17.9%; P < .001). There was no difference between groups in terms of comorbidities, being on dialysis, or functional status, yet the EVAR + RAAS group had a higher proportion of patients with glomerular filtration rate <60 mL/min/1.73 m2 (45.2% vs 37.2%; P = .011). RAAS was associated with significantly higher odds for development of ARF (adjusted odds ratio [aOR], 4.27; 95% confidence interval [CI], 2.06-8.84; P < .001). Other highly predictive factors of 30-day ARF were glomerular filtration rate <60 (aOR, 2.92; 95% CI, 1.47-5.78; P = .002), emergency status (aOR, 2.97; 95% CI, 1.21-7.27; P = .017), and ruptured AAA as the indication for EVAR (aOR, 4.74; 95% CI, 1.80-12.50; P = .002). Patients with prior kidney disease who had EVAR + RAAS demonstrated a 12-fold higher odds for 30-day ARF (aOR, 12.37; 95% CI, 4.66-32.89; P < .001).

CONCLUSIONS

Concurrent RAAS was found to be a significant determinant of adverse renal outcomes after EVAR for infrarenal AAA. This effect was present even after controlling for patients' risk factors that might contribute to postoperative ARF.

Management of Immediate Post-Endovascular Aortic Aneurysm Repair Type Ia Endoleaks and Late Outcomes

BACKGROUND

Post-endovascular aortic aneurysm repair (EVAR) endoleaks and the need for reintervention are challenging. Additional endovascular treatment is advised for type Ia endoleaks detected on post-EVAR completion angiogram. This study analyzed management and late outcomes of these endoleaks.

STUDY DESIGN

This was a retrospective review of prospectively collected data from EVAR patients during a 10-year period. All post-EVAR type Ia endoleaks on completion angiogram were identified (group A) and their early (30-day) and late outcomes were compared with outcomes of patients without endoleaks (group B). Kaplan-Meier analysis was used for survival analysis, sac expansion, late type Ia endoleak, and reintervention.

RESULTS

Seventy-one of 565 (12.6%) patients had immediate post-EVAR type Ia endoleak. Early intervention (proximal aortic cuffs and/or stenting) was used in 56 of 71 (79%) in group A vs 31 of 494 (6%) in group B (p < 0.0001). Late type Ia endoleak was noted in 9 patients (13%) in group A at a mean follow-up of 28 months vs 10 patients (2%) in group B at a mean follow-up of 32 months (p < 0.0001). Late sac expansion and reintervention rates were 9% and 10% for group A vs 5% and 3% for group B (p = 0.2698 and p = 0.0198), respectively. Freedom rates from late type Ia endoleaks at 1, 3, and 5 years for group A were 88%, 85%, and 80% vs 98%, 98%, and 96% for group B (p < 0.001); and for late intervention, were 94%, 92%, and 77% for group A, and 99%, 97%, and 95% for group B (p = 0.007), respectively. Survival rates were similar.

CONCLUSIONS

Immediate post-EVAR type Ia endoleaks are associated with higher rates of early interventions, late endoleaks and reintervention, which will necessitate strict post-EVAR surveillance.

Postoperative renal dysfunction independently predicts late mortality in patients undergoing aortic reconstruction

OBJECTIVE

Preoperative chronic kidney disease (CKD) has been shown to predict postoperative renal complications and mortality after open aortic surgery; the impact of postoperative renal complications less severe than permanent dialysis are unknown. We evaluated the impact of postoperative renal dysfunction severity on survival using a regional quality improvement registry.

METHODS

Patients undergoing intact open aortic reconstruction in the Vascular Study Group of New England registry (2003-2012) were stratified by severity of postoperative renal complications; none, creatinine increase of greater than 0.5 mg/dL (incCr), or any hemodialysis (HD). Predictors of renal dysfunction and impact of renal complications on survival were analyzed using multivariable methods.

RESULTS

We included 2695 patients, of which 65% (n = 1733) underwent open abdominal aortic aneurysm repair, and 35% (n = 962) open aortoiliac reconstruction. At baseline, 15% of patients had preoperative moderate CKD and 1.2% had severe CKD. Postoperative renal complications of incCr occurred in 8.5% of patients, and 1.5% required HD. Multivariable cumlogit regression identified severe baseline CKD (odds ratio [OR], 15; 95% confidence interval [CI], 6.4-34; P < .001, moderate CKD (OR, 2.8; 95% CI, 1.9-3.3; P < .001), suprarenal clamp use (OR, 2.2; 95% CI, 1.6-2.9; P < .001), perioperative vasopressor requirements (OR, 2.2; 95% CI, 1.6-2.9; P < .001), operating time (OR, 1.004 per minute; 95% CI, 1.003-1.006; P < .001), and chronic obstructive pulmonary disease (OR, 1.5; 95% CI, 1.2-1.8; P < .001) as independent predictors of worsening strata of postoperative renal dysfunction. Multivariable logistic regression analysis showed that patient age (OR, 1.06 per year; 95% CI, 1.01-1.1; P = .01), baseline chronic obstructive pulmonary disease (OR, 1.6; 95% CI, 1.2-2.2; P < .01), incCr (OR, 3.7; 95% CI, 1.8-7.4; P = .009), and HD (OR, 4.8; 95% CI, 1.8-12.7); P = .009) independently increased 30-day mortality. Risk-adjusted multivariable Cox regression showed that incCr (hazard ratio, 1.8; 95% CI, 1.3-2.6; P < .001) and HD (hazard ratio, 4.4; 95% CI, 2.8-6.9; P < .001) increased risk of late death independent of a variety of other clinical variables, including baseline CKD. The 5-year survival was lower (log-rank P < .001) in patients with incCr (66% ± 4%), and HD (38% ± 10%) compared with those with no renal complications (77% ± 1%).

CONCLUSIONS

Increasing severity of postoperative renal dysfunction independently predicts increased risk of late mortality after open aortic surgery. Perioperative measures to decrease renal complications may potentially prolong the survival of patients after open aortic surgery.

The impact of concomitant procedures during endovascular abdominal aortic aneurysm repair on perioperative outcomes

BACKGROUND

Concomitant procedures during endovascular aneurysm repair (EVAR) of an abdominal aortic aneurysm are performed to facilitate endograft delivery, to simultaneously treat unrelated conditions, or to resolve intraoperative pitfalls. The frequency and perioperative impact of these procedures are not well described. This study aimed to assess the frequency and perioperative impact of various concomitant procedures performed at the time of EVAR.

METHODS

We included all elective EVARs in the Vascular Study Group of New England between January 2003 and November 2014 and identified those with and those without concomitant procedures. Multivariable logistic regression analysis was used to establish the independent association between concomitant procedures and perioperative outcomes.

RESULTS

The study included 4033 patients, with 1168 (29.0%) patients undergoing one or more additional procedures. Independent risk factors for 30-day mortality were concomitant femoral endarterectomy (odds ratio [OR], 4.8; 95% confidence interval [CI], 2.1-11.2) and renal angioplasty or stenting (OR, 3.1; 95% CI, 1.2-8.3). Postoperative bowel ischemia was associated with hypogastric embolization (OR, 3.8; 95% CI, 1.1-13.4) and iliac angioplasty or stenting (OR, 3.5; 95% CI, 1.3-9.6). Leg ischemia was associated with unplanned graft extension (OR, 2.3; 95% CI, 1.02-5.0), other artery reconstruction (OR, 5.2; 95% CI, 1.8-15.1), thromboembolectomy (OR, 5.2; 95% CI, 1.3-20.8), and repair of arterial injury (OR, 4.6; 95% CI, 1.2-18.3). Risk factors for deterioration of renal function were iliofemoral bypass (OR, 3.9; 95% CI, 1.3-12.2), other artery reconstruction (OR, 2.7; 95% CI, 1.3-5.8), renal angioplasty or stenting (OR, 2.5; 95% CI, 1.3-4.6), and repair of arterial injury (OR, 4.5; 95% CI, 1.6-12.2). Myocardial infarction was associated with femorofemoral bypass (OR, 3.9; 95% CI, 1.7-8.7), other artery reconstruction (OR, 3.9; 95% CI, 1.6-9.2), and repair of arterial injury (OR, 6.1; 95% CI, 1.8-21.0). Wound complications were predicted by femorofemoral bypass (OR, 13.4; 95% CI, 5.8-31.1).

CONCLUSIONS

Concomitant procedures during EVAR are associated with increased postoperative morbidity and mortality. The need for performing concomitant procedures should be carefully considered. The morbidity associated with intraoperative complications highlights the importance of avoidance of arterial injury and thromboembolic events where possible.

Endovascular repair of abdominal aortic aneurysms: vascular anatomy, device selection, procedure, and procedure-specific complications

Abdominal aortic aneurysm (AAA) is abnormal dilatation of the aorta, carrying a substantial risk of rupture and thereby marked risk of death. Open repair of AAA involves lengthy surgery time, anesthesia, and substantial recovery time. Endovascular aneurysm repair (EVAR) provides a safer option for patients with advanced age and pulmonary, cardiac, and renal dysfunction. Successful endovascular repair of AAA depends on correct selection of patients (on the basis of their vascular anatomy), choice of the correct endoprosthesis, and familiarity with the technique and procedure-specific complications. The type of aneurysm is defined by its location with respect to the renal arteries, whether it is a true or false aneurysm, and whether the common iliac arteries are involved. Vascular anatomy can be divided more technically into aortic neck, aortic aneurysm, pelvic perfusion, and iliac morphology, with grades of difficulty with respect to EVAR, aortic neck morphology being the most common factor to affect EVAR appropriateness. When choosing among the devices available on the market, one must consider the patient's vascular anatomy and choose between devices that provide suprarenal fixation versus those that provide infrarenal fixation. A successful technique can be divided into preprocedural imaging, ancillary procedures before AAA stent-graft placement, the procedure itself, postprocedural medical therapy, and postprocedural imaging surveillance. Imaging surveillance is important in assessing complications such as limb thrombosis, endoleaks, graft migration, enlargement of the aneurysm sac, and rupture. Last, one must consider the issue of radiation safety with regard to EVAR.