Assessment of fitness for open repair in patients with infrarenal abdominal aortic aneurysms.

OBJECTIVE: Endovascular aortic repair (EVAR) was originally designed as a treatment modality for patients with abdominal aortic aneurysms (AAAs) deemed unfit for open repair. However, the definition of "unfit for open repair" is largely subjective and heterogenous. The purpose of this study was to compare patients deemed unfit for open repair who underwent EVAR to a matched cohort who underwent open repair for infrarenal AAAs. METHODS: The Vascular Quality Initiative of the Society for Vascular Surgery was queried for patients who underwent EVAR and open infrarenal AAA repair from 2003 to 2022. Patients that underwent EVAR were included if they were deemed unfit for open repair by the operating surgeon. EVAR patients deemed unfit because of a hostile abdomen were excluded. Patients in both the open and EVAR datasets were excluded if their repair was deemed non-elective or if they had prior aortic surgery. EVAR patients were matched to a cohort of open patients. The primary outcome for this study was 1-year mortality. Secondary outcomes included 30-day mortality, major adverse cardiac events, pulmonary complications, non-home discharge, reinterventions, and 5-year survival. RESULTS: A total of 5310 EVAR patients were identified who were deemed unfit for open repair. Of those, 3028 EVAR patients (57.0%) were able to be matched 1:1 to a cohort of open patients. Open patients had higher rates of major adverse cardiac events (20.2% vs 4.4%; P < .001), pulmonary complications (12.8% vs 1.6%; P < .001), non-home discharges (28.5% vs 7.9%; P < .001), and 30-day mortality (4.5% vs 1.4%; P < .001). There were no differences in early survival, but open repair had better middle and late survival compared with EVAR over the course of 5 years. A total of 74 EVAR patients (2.4%) had reinterventions during the study period. EVAR patients that required interventions had higher 1-year (40.5% vs 7.3%; P < .001) and 5-year mortality (43.2% vs 14.1%; P < .001) compared with those that did not require reinterventions. EVAR patients who had reinterventions had higher 1-year (40.5% vs 6.3%; P < .001) and 5-year (43.2% vs 20.3%; P = .006) mortality compared with their matched open cohort. CONCLUSIONS: Patients undergoing EVAR for AAAs who are deemed unfit for open repair have better perioperative morbidity and mortality compared with open repair. However, patients who had an open repair had better middle and late survival over the course of 5 years. The categorization of unfitness for open surgery may be inaccurate and re-evaluation of this terminology/concept should be undertaken.

Image-based assessment of aortoiliac aneurysm anatomical characteristics in patients from the global iliac branch study.

OBJECTIVE: Endovascular repair is the preferred treatment for aortoiliac aneurysm, with preservation of at least one internal iliac artery recommended. This study aimed to assess pre-endovascular repair anatomical characteristics of aortoiliac aneurysm in patients from the Global Iliac Branch Study (GIBS, NCT05607277) to enhance selection criteria for iliac branch devices (IBD) and improve long-term outcomes. METHODS: Pre-treatment CT scans of 297 GIBS patients undergoing endovascular aneurysm repair were analyzed. Measurements included total iliac artery length, common iliac artery length, tortuosity index, common iliac artery splay angle, internal iliac artery stenosis, calcification score, and diameters in the device's landing zone. Statistical tests assessed differences in anatomical measurements and IBD-mediated internal iliac artery preservation. RESULTS: Left total iliac artery length was shorter than right (6.7 mm, P = .0019); right common iliac artery less tortuous (P = .0145). Males exhibited greater tortuosity in the left total iliac artery (P = .0475) and larger diameter in left internal iliac artery's landing zone (P = .0453). Preservation was more common on right (158 unilateral, 34 bilateral) than left (105 unilateral, 34 bilateral). There were 192 right-sided and 139 left-sided IBDs, with 318 IBDs in males and 13 in females. CONCLUSION: This study provides comprehensive pre-treatment iliac anatomy analysis in patients undergoing endovascular repair with IBDs, highlighting differences between sides and sexes. These findings could refine patient selection for IBD placement, potentially enhancing outcomes in aortoiliac aneurysm treatment. However, the limited number of females in the study underscores the need for further research to generalize findings across genders.

Long-term costs to Medicare associated with endovascular and open repairs of infrarenal and complex abdominal aortic aneurysms.

OBJECTIVE: The vast majority of patients with abdominal aortic aneurysms (AAAs) undergoing repairs receive endovascular interventions (EVARs) instead of open operations (OARs). Although EVARs have better short-term outcomes, OARs have improved longer-term durability and require less radiographic follow-up and monitoring, which may have significant implications on health care economics surrounding provision of AAA care nationally. Herein, we compared costs associated with EVAR and OAR of both infrarenal and complex AAAs. METHODS: We examined patients undergoing index elective EVARs or OARs of infrarenal and complex AAAs in the 2014-2019 Vascular Quality Initiative-Vascular Implant Surveillance and Interventional Outcomes Network (VQI-VISION) dataset. We defined overall costs as the aggregated longitudinal costs associated with: (1) the index surgery; (2) reinterventions; and (3) imaging tests. We evaluated overall costs up to 5 years after infrarenal AAA repair and 3 years for complex AAA repair. Multivariable regressions adjusted for case-mix when evaluating cost differences between EVARs vs OARs. RESULTS: We identified 23,746 infrarenal AAA repairs (8.7% OAR, 91% EVAR) and 2279 complex AAA repairs (69% OAR, 31% EVAR). In both cohorts, patients undergoing EVARs were more likely to be older and have more comorbidities. The cost for the index procedure for EVARs relative to OARs was lower for infrarenal AAAs ($32,440 vs $37,488; P < .01) but higher among complex AAAs ($48,870 vs $44,530; P < .01). EVARs had higher annual imaging and reintervention costs during each of the 5 postoperative years for infrarenal aneurysms and the 3 postoperative years for complex aneurysms. Among patients undergoing infrarenal AAA repairs who survived 5 years, the total 5-year cost of EVARs was similar to that of OARs ($35,858 vs $34,212; -$223 [95% confidence interval (CI), -$3042 to $2596]). For complex AAA repairs, the total cost at 3 years of EVARs was greater than OARs ($64,492 vs $42,212; +$9860 [95% CI, $5835-$13,885]). For patients receiving EVARs for complex aneurysms, physician-modified endovascular grafts had higher index procedure costs ($55,835 vs $47,064; P < .01) although similar total costs on adjusted analyses (+$1856 [95% CI, -$7997 to $11,710]; P = .70) relative to Zenith fenestrated endovascular grafts among those that were alive at 3 years. CONCLUSIONS: Longer-term costs associated with EVARs are lower for infrarenal AAAs but higher for complex AAAs relative to OARs, driven by reintervention and imaging costs. Further analyses to characterize the financial viability of EVARs for both infrarenal and complex AAAs should evaluate hospital margins and anticipated changes in costs of devices.

The ARIA trial protocol: a randomised controlled trial to assess the clinical, technical, and cost-effectiveness of a cloud-based, ARtificially Intelligent image fusion system in comparison to standard treatment to guide endovascular Aortic aneurysm repair.

BACKGROUND: Endovascular repair of aortic aneurysmal disease is established due to perceived advantages in patient survival, reduced postoperative complications, and shorter hospital lengths of stay. High spatial and contrast resolution 3D CT angiography images are used to plan the procedures and inform device selection and manufacture, but in standard care, the surgery is performed using image-guidance from 2D X-ray fluoroscopy with injection of nephrotoxic contrast material to visualise the blood vessels. This study aims to assess the benefit to patients, practitioners, and the health service of a novel image fusion medical device (Cydar EV), which allows this high-resolution 3D information to be available to operators at the time of surgery. METHODS: The trial is a multi-centre, open label, two-armed randomised controlled clinical trial of 340 patient, randomised 1:1 to either standard treatment in endovascular aneurysm repair or treatment using Cydar EV, a CE-marked medical device comprising of cloud computing, augmented intelligence, and computer vision. The primary outcome is procedural time, with secondary outcomes of procedural efficiency, technical effectiveness, patient outcomes, and cost-effectiveness. Patients with a clinical diagnosis of AAA or TAAA suitable for endovascular repair and able to provide written informed consent will be invited to participate. DISCUSSION: This trial is the first randomised controlled trial evaluating advanced image fusion technology in endovascular aortic surgery and is well placed to evaluate the effect of this technology on patient outcomes and cost to the NHS. TRIAL REGISTRATION: ISRCTN13832085. Dec. 3, 2021.

One-time screening for abdominal aortic aneurysm in Ontario, Canada: a model-based cost-utility analysis.

BACKGROUND: Screening programs for abdominal aortic aneurysm (AAA) are not available in Canada. We sought to determine the effectiveness and costutility of AAA screening in Ontario. METHODS: We compared one-time ultrasonography-based AAA screening for people aged 65 years to no screening using a fully probabilistic Markov model with a lifetime horizon. We estimated life-years, quality-adjusted life-years (QALYs), AAA-related deaths, number needed to screen to prevent 1 AAA-related death and costs (in Canadian dollars) from the perspective of the Ontario Ministry of Health. We retrieved model inputs from literature, Statistics Canada, and the Ontario Case Costing Initiative. RESULTS: Screening reduced AAA-related deaths by 84.9% among males and 81.0% among females. Compared with no screening, screening resulted in 0.04 (18.96 v. 18.92) additional life-years and 0.04 (14.95 v. 14.91) additional QALYs at an incremental cost of $80 per person among males. Among females, screening resulted in 0.02 (21.25 v. 21.23) additional life-years and 0.01 (16.20 v. 16.19) additional QALYs at an incremental cost of $11 per person. At a willingness-to-pay of $50 000 per year, screening was cost-effective in 84% (males) and 90% (females) of model iterations. Screening was increasingly cost-effective with higher AAA prevalence. INTERPRETATION: Screening for AAA among people aged 65 years in Ontario was associated with fewer AAA-related deaths and favourable cost-effectiveness. To maximize QALY gains per dollar spent and AAA-related deaths prevented, AAA screening programs should be designed to ensure that populations with high prevalence of AAA participate.

Size thresholds for repair of abdominal aortic aneurysms warrant reconsideration.

BACKGROUND: The historical size threshold for abdominal aortic aneurysm (AAA) repair is widely accepted to be 5.5 cm for men and 5.0 cm for women. However, contemporary AAA rupture risks may be lower than historical benchmarks, which has implications for when AAAs should be repaired. Our objective was to use contemporary AAA rupture rates to inform optimal size thresholds for AAA repair. METHODS: We used a Markov chain analysis to estimate life expectancy for patients with AAA. The primary outcome was AAA-related mortality. We estimated survival using Social Security Administration life tables and published contemporary AAA rupture estimates. For those undergoing repair, we modified survival estimates using data from the Vascular Quality Initiative and Medicare on complications, late rupture, and open conversion. We used this model to estimate the AAA repair size threshold that minimizes AAA-related mortality for 60-year-old average-health men and women. We performed a sensitivity analysis of poor-health patients and 70- and 80-year-old base cases. RESULTS: The annual risk of all-cause mortality under surveillance for a 60-year-old woman presenting with a 5.0 cm AAA using repair thresholds of 5.5 cm, 6.0 cm, 6.5 cm, and 7.0 cm was 1.7%, 2.3%, 2.7%, and 2.8%, respectively. The corresponding risk for a man was 2.3%, 2.9%, 3.3%, and 3.4% for the same repair thresholds, respectively. For a 60-year-old average-health woman, an AAA repair size of 6.1 cm was the optimal threshold to minimize AAA-related mortality. Life expectancy varied by <2 months for repair at sizes from 5.7 cm to 7.1 cm. For a 60-year-old average-health man, an AAA repair size of 6.9 cm was the optimal threshold to minimize AAA-related mortality. Life expectancy varied by <2 months for repair at sizes from 6.0 cm to 7.4 cm. Women in poor health, at various age strata, had optimal AAA repair size thresholds that were >6.5 cm, whereas men in poor health, at all ages, had optimal repair size thresholds that were >8.0 cm. CONCLUSIONS: The optimal threshold for AAA repair is more nuanced than a discrete size. Specifically, there appears to be a range of AAA sizes for which repair is reasonable to minmized AAA-related mortality. Notably, they all are greater than current guideline recommendations. These findings would suggest that contemporary AAA size thresholds for repair should be reconsidered.

Initial two-day blood pressure management after endovascular aneurysm repair improves midterm outcomes by reducing the incidence of early type II endoleak.

OBJECTIVE: The aim of this study was to evaluate midterm outcomes of our novel strategy of postoperative initial 2-day blood pressure management (BPM) after endovascular aneurysm repair (EVAR) for the prevention of subsequent type II endoleak (T2EL) in a single-center series. METHODS: Between 2008 and 2014, 137 patients who underwent EVAR for abdominal aortic aneurysm (AAA) were reviewed. Starting from 2013, the mean blood pressure was maintained between 75 and 90 mmHg for the initial 24 hours after EVAR followed by systolic pressure controlled below 120 mmHg during the next 24 hours in the treatment group (n = 76). The incidence of T2EL detected at 7 days, reintervention, and AAA sac diameter up to 5 years after EVAR were compared with those of the control group comprising of 60 consecutive patients who underwent standard EVAR without BPM prior to 2013. RESULTS: Between the treatment group and the control group, significant differences were achieved in the incidence of T2EL at 7 days (19.7% vs 40.0%; P = .009), a mean decrease of AAA sac diameter at 1-year (-5.1 ± 4.9 vs -2.2 ± 6.7 mm; P = .013) and 2-year (-5.4 ± 7.7 vs -1.7 ± 10.8 mm; P = .045). In addition, there was a significant decrease in the incidence of T2EL detected at 7 days with the use of the Gore Excluder with 22.7% in the treatment group vs 80.0% in the control group (P < .001), which resulted in a significant decrease in the aneurysm sac diameter up to 4 years after EVAR. Survival rate without AAA sac enlargement at 5 years after EVAR (83.0% vs 70.0%; P = .021) in the treatment group was significantly higher than that of the control group, whereas no significant differences were observed in the freedom rates of reintervention, T2EL-related reintervention, and all-cause mortality between the groups. CONCLUSIONS: Postoperative initial 2-day BPM had a preventive effect on AAA sac enlargement until midterm periods, by reducing the incidence of T2EL at 7 days after EVAR. The usage of Gore Excluder under BPM was especially associated with sustained positive effects until the midterm follow-up.

One-year aneurysm-sac dynamics are associated with reinterventions and rupture following infrarenal endovascular aneurysm repair.

OBJECTIVE: One-year aneurysm sac changes have previously been found to be associated with mortality and may have the potential to guide personalized follow-up following endovascular aneurysm repair (EVAR). In this study, we examined the association of these early sac changes with long-term reintervention and rupture. METHODS: We identified all patients undergoing first-time EVAR for intact abdominal aortic aneurysm between 2003 and 2018 in the Vascular Quality Initiative with linkage to Medicare claims for long-term outcomes. We included patients with an imaging study at 1 year postoperatively. Aneurysm sac behavior was defined as per the Society for Vascular Surgery guidelines: stable sac (<5 mm change), sac regression (≥5 mm), and sac expansion (≥5 mm). Outcomes included mortality, reintervention, and rupture within 8 years, which were assessed with Kaplan-Meier methods and multivariable Cox regression analysis. Secondarily, we utilized polynomial spline interpolation to demonstrate the continuous relationship of diameter change to 8-year hazard of reintervention, rupture, or mortality as a composite outcome. RESULTS: Of 31,185 EVAR patients, 16,102 (52%) had an imaging study at 1 year and were included in this study. At 1 year, 44% of sacs remained stable, 49% regressed, and 6.2% displayed expansion. Following risk adjustment, compared with a stable sac at 1 year, sac regression was associated with lower 8-year mortality (49% vs 53%; hazard ratio [HR], 0.92; 95% confidence interval [CI], 0.85-0.99; P = .036), reintervention rate (8.9% vs 15%; HR, 0.58; 95% CI, 0.50-0.68; P < .001), and rupture rate (2.0% vs 4.0%; HR, 0.45; 95%CI, 0.29-0.69; P < .001). Conversely, compared with a stable sac, sac expansion was associated with higher 8-year mortality (64% vs 53%; HR, 1.31; 95% CI, 1.14-1.51; P < .001) and reintervention rate (27% vs 15%; HR, 1.98; 95% CI, 1.57-2.51; P < .001), but similar risk of rupture (7.2% vs 4.0%; HR, 1.61; 95% CI, 0.88-2.96; P = .12). Polynomial spline interpolation demonstrated that, compared with no diameter change at 1 year, increased sac regression was associated with an incrementally lower risk of late outcomes, whereas increased sac expansion was associated with an incrementally higher risk of late outcomes. CONCLUSIONS: Following EVAR, compared with a stable sac at 1-year imaging, sac regression and expansion are associated with a lower and higher risk respectively of long-term mortality, reinterventions, and ruptures. Moreover, the amount of regression or expansion seems to be incrementally associated with these late outcomes, too. Future studies are needed to determine how to improve 1-year sac regression, and whether it is safe to extend follow-up intervals for patients with regressing sacs.

Prospective assessment of dynamic changes in frailty and its impact on early clinical outcomes following physician-modified fenestrated-branched endovascular repair of complex abdominal and thoracoabdominal aortic aneurysms.

INTRODUCTION: Frailty, a predictor of poor outcomes, has been widely studied as a screening tool in surgical decision-making. However, the impact of frailty on the outcomes after fenestrated-branched endovascular aortic repairs (FBEVARs) is less well established. In addition, the changes in frailty during recovery after FBEVAR are unknown. We aim to assess the impact of frailty on outcomes of high-risk patients undergoing physician-modified FBEVARs for complex abdominal and thoracoabdominal aortic aneurysms, as well as the changes in frailty during follow-up. METHODS: Consecutive patients enrolled in a single-center prospective Physician-Sponsored Investigational Device Exemption protocol (FDA# G200159) were evaluated. In addition to the baseline characteristics, frailty was assessed using the Hopkins Frailty Score (HFS) and frailty index (FI) measured by the Frailty Meter. Sarcopenia was measured by L3 total psoas muscle area (PMA). These measurements were repeated during follow-up. The follow-up HFS and FI were compared with baseline scores using the Wilcoxon signed-rank test, whereas follow-up PMA measurements were compared with the baseline using the paired t test. The association between baseline frailty and morbidity was evaluated by the Wilcoxon rank-sum test. RESULTS: Seventy patients were analyzed in a prospective Physician-Sponsored Investigational Device Exemption study from February 9, 2021, to June 2, 2023. At baseline, HFS identified 54% of patients as not frail, 43% as intermediately frail, and 3% as frail. Technical success of FBEVAR was 94% with one in-hospital mortality. Early major adverse events were seen in 10 (14.3%) patients. No difference in baseline FI was seen between patients with early morbidity and those without. Patients who were not frail per HFS were less likely to experience early morbidity (P = .033), and there was a significantly lower baseline PMA in patients who experienced early morbidity (P = .016). At 1 month, patients experienced a significant increase in HFS and HFS category (P = .001 and P = .01) and a significant decrease in sarcopenia (mean PMA: -96 mm2, P = .005). At 6 months, HFS and HFS category as well as PMA returned toward baseline (P = .42, P = .38, and mean PMA: +4 mm2, P = .6). CONCLUSIONS: Preoperative frailty and sarcopenia were associated with early morbidity after physician-modified FBEVAR. During follow-up, patients became more frail and sarcopenic by 1 month. Recovery from this initial decline was seen by 6 months, suggesting that frailty and sarcopenia are reversible processes rather than a unidirectional phenomenon of continued decline.

An Analysis of Cost-Effectiveness and Clinical Outcomes of a Comprehensive Aortic Service in a Tertiary Center over One Year.

BACKGROUND: Endovascular aortic repair (EVAR) is an established and attractive alternative to open surgical repair (OSR) of abdominal aortic aneurysms (AAA) due to its superior short-term safety profile. However, opinions are divided regarding its long-term cost-effectiveness. We compared the total yearly cost of running endovascular and OSR services in a single tertiary center to determine whether fenestrated EVAR (FEVAR) represents a clinically efficacious, affordable treatment option. METHODS: A single-center retrospective review was performed on 109 patients undergoing a procedure related to index or previous abdominal aortic repair, with 1 year follow-up. Data was collected from the National Vascular Registry and hospital records. The primary outcome was cost per quality-adjusted life year. Secondary outcomes included 30-day mortality and morbidity, reintervention rates, length of hospital stay, aneurysm, and all-cause mortality at 1 year for elective index procedures. RESULTS: The average cost per patient of all FEVAR was £16,041.53 (±8,857.54), £13,893.51 (±£21,425.25) for standard EVAR, and £15,357.22 (±£15,904.49) for OSR (FEVAR versus EVAR P = 0.55, FEVAR versus OSR P = 0.83, OSR versus EVAR P = 0.76). Of the secondary outcomes, significant findings included increased length of stay and respiratory morbidity for patients undergoing open versus endovascular repair. There was no significant difference in 30-day or 1-year mortality between groups. CONCLUSIONS: FEVAR, EVAR, and OSR all represent cost-effective options for aortic repair with similar outcomes. Our data highlights the potential for FEVAR to present a viable alternative to open repair, particularly in higher-risk groups, when performed in specialist centers.

Effectiveness of Intra-operative Contrast-Enhanced Ultrasound Assessment to Optimize Type II Endoleak Embolization.

PURPOSE: To analyze the effectiveness of type II endoleaks (T2E) embolization using intra-operative contrast-enhanced ultrasound (CEUS). METHODS: Consecutive patients treated for T2E underwent a standardized protocol with trans-arterial or trans-lumbar access, large volume embolization, onlay fusion, and intra-operative CEUS. Technical success was defined by exclusion of endoleak by CEUS. RESULTS: Twenty-six patients (mean age 81 ± 11 years old; 89% male) were treated. The mean aneurysm sac enlargement was 11 ± 8 mm from T2E diagnosis. Embolization was performed using Onyx® 18 in all patients with adjunctive coils in 13 patients (50%). After the first embolization, CEUS documented residual T2E in 13 patients (50%). Ten patients (38%) had additional embolization, which successfully eradicated the T2E in seven of them. Technical success was 50% after the first embolization attempt and 77% after additional attempts guided by CEUS (P = 0.080). There was no mortality. Median imaging follow-up was 22 months. Among the 20 patients with no residual T2E on completion CEUS, 16 (80%) had sac stabilization and none required additional interventions for T2E. Of the six patients with residual T2Es on CEUS, three had sac stabilization (50%) and one required additional reintervention for T2E. There was one late aortic rupture at 56 months. CONCLUSION: One in two patients treated by T2E embolization had residual endoleak on intra-operative CEUS after a first embolization attempt, decreasing to one in four patients after multiple attempts. A negative completion CEUS following embolization was associated with higher rates of sac stabilization and no need for additional T2E embolization.

Vascular Ultrasound for In Vivo Assessment of Arterial Pathologies in a Murine Model of Atherosclerosis and Aortic Aneurysm.

Vascular diseases like atherosclerosis and abdominal aortic aneurysm (AAA) are common pathologies in the western world, promoting various potentially fatal conditions. Here, we evaluate high-resolution (HR) ultrasound in mouse models of atherosclerosis and AAA as a useful tool for noninvasive monitoring of early vascular changes in vivo. We used Apolipoprotein E-deficient (ApoE-/-) mice as an atherosclerosis model and induced AAA development by the implementation of Angiotensin II-releasing osmotic minipumps. HR ultrasound of the carotid artery or the abdominal aorta was performed to monitor vascular remodeling in vivo. Images were analyzed by speckle tracking algorithms and correlated to histological analyses and subsequent automated collagen quantification. Consistent changes were observed via ultrasound in both models: Global radial strain (GRS) was notably reduced in the AAA model (23.8 ± 2.8% vs. 12.5 ± 2.5%, p = 0.01) and in the atherosclerotic mice (20.6 ± 1.3% vs. 15.8 ± 0.9%, p = 0.02). In mice with AAA, vessel distensibility was significantly reduced, whereas intima-media thickness was increased in atherosclerotic mice. The area and collagen content of the tunica media were increased in diseased arteries of both models as measured by automated image analysis of Picrosirius Red-stained aortic sections. Correlation analysis revealed a strong correlation of multiple parameters, predicting early vascular damage in HR ultrasound and histological examinations. In conclusion, our findings underscore the potential of HR ultrasound in effectively tracing early alterations in arterial wall properties in murine models of atherosclerosis and AAA.

Insulin Dependence is Associated with Poor Long-Term Outcomes Following AAA Repair.

BACKGROUND: While prior studies have confirmed the protective effect of diabetes on abdominal aortic aneurysm (AAA) development, much less is known about the effect of diabetes, and in particular insulin dependence, on outcomes following AAA repair. In this study, we aim to evaluate the role of insulin-dependent diabetes on short-term and long-term outcomes following open and endovascular AAA repair. METHODS: The Vascular Implant Surveillance and Interventional Outcomes Network (VISION), a registry linking the Vascular Quality Initiative (VQI) data with Medicare claims, was queried for patients who underwent open or endovascular AAA repair from 2011 to the present. Exclusion criteria were unknown diabetes status, prior aortic intervention, maximum aneurysm diameter <45 mm at presentation, and Medicare Advantage coverage due to inconsistent follow-up. Patients were stratified based on diabetes status (no diabetes versus diabetes) and insulin dependence (no diabetes or non-insulin-dependent diabetes versus insulin-dependent diabetes). RESULTS: Of the 38,437 cases in the VISION endovascular aortic aneurysm (EVAR) and open aortic aneurysm repair (OAR) databases, 21,943 met inclusion criteria. Perioperative outcomes after OAR were comparable between diabetic and nondiabetic patients. However, diabetic patients undergoing EVAR were significantly more likely to have a postoperative myocardial infarction (1.0% vs 0.6%, P = 0.04) and have a 30-day readmission (10.9% vs 8.8%, P < 0.001). Insulin-dependent diabetic patients were more likely to require a 30-day readmission after OAR (24.5% vs 13.5%, P = 0.02) and EVAR (15.1% vs 9.0%, P < 0.001); however, only insulin-dependent diabetes mellitus (IDDM) patients undergoing EVAR experienced higher rates of postoperative myocardial infarction (1.9% vs 0.7%, P < 0.01). After propensity score matching, patients with IDDM undergoing EVAR were additionally at increased risk of mortality at 1-year, 3-year, and 5-year follow-up with the highest risk occurring at the 1-year mark (hazard ratio 1.79, P < 0.0001), while IDDM patients undergoing OAR were only at a significantly increased risk of mortality at 5-year follow-up (hazard ratio 1.90, P = 0.01). CONCLUSIONS: Patients with insulin-dependent diabetes have greater than 14% one-year mortality following open or endovascular aneurysm repair, compared to 8% for all others. Our findings raise questions about whether insulin-dependent diabetics should have a higher size threshold for prophylactic repair, although further studies are needed to address this question and consider the influence of glycemic control on these outcomes.

Three-dimensional growth and biomechanical risk progression of abdominal aortic aneurysms under serial computed tomography assessment.

Growth of abdominal aortic aneurysms (AAAs) is often described as erratic and discontinuous. This study aimed at describing growth patterns of AAAs with respect to maximal aneurysm diameter (Dmax) and aneurysm volume, and to characterize changes in the intraluminal thrombus (ILT) and biomechanical indices as AAAs grow. 384 computed tomography angiographies (CTAs) from 100 patients (mean age 70.0, standard deviation, SD = 8.5 years, 22 women), who had undergone at least three CTAs, were included. The mean follow-up was 5.2 (SD = 2.5) years. Growth of Dmax was 2.64 mm/year (SD = 1.18), volume 13.73 cm3/year (SD = 10.24) and PWS 7.3 kPa/year (SD = 4.95). For Dmax and volume, individual patients exhibited linear growth in 87% and 77% of cases. In the tertile of patients with the slowest Dmax-growth (< 2.1 mm/year), only 67% belonged to the slowest tertile for volume-growth, and 52% and 55% to the lowest tertile of PWS- and PWRI-increase, respectively. The ILT-ratio (ILT-volume/aneurysm volume) increased with time (2.6%/year, p < 0.001), but when adjusted for volume, the ILT-ratio was inversely associated with biomechanical stress. In contrast to the notion that AAAs grow in an erratic fashion most AAAs displayed continuous and linear growth. Considering only change in Dmax, however, fails to capture the biomechanical risk progression, and parameters such as volume and the ILT-ratio need to be considered.

Greater Patient Travel Distance is Associated with Perioperative and One-Year Cost Increases After Complex Aortic Surgery.

BACKGROUND: With increasing regionalization of complex aortic surgery within fewer US centers, patients may face increased travel burden when accessing aortic surgery. Longer travel distances have been associated with inferior outcomes after major surgery; however, the impacts of distance on reinterventions and costs have not been described. This study aims to assess the association between patient travel distance and longer-term outcomes including costs and reinterventions after complex aortic surgery. METHODS: A retrospective review was conducted of all patients in the Vascular Implant Surveillance and Interventional Outcomes Network database undergoing complex endovascular aortic repair including internal iliac or visceral vessel involvement, complex thoracic endovascular aortic repair including Zone 0-2 proximal extent or branched devices, and complex open abdominal aortic aneurysm repair including suprarenal or higher clamp sites. Travel distance was stratified by Rural-Urban Commuting Area population-density category. Multinomial logistic regression models, negative-binomial models, and zero-inflated Poisson models were used to assess the association between travel distance and index procedural and comprehensive first-year costs, long-term imaging, and long-term reinterventions, respectively. RESULTS: Between 2011 and 2018, 8,782 patients underwent complex aortic surgery in the Vascular Implant Surveillance and Interventional Outcomes Network database, including 4,822 complex endovascular aortic repairs, 2,672 complex thoracic endovascular aortic repairs, and 1,288 complex open abdominal aortic aneurysm repairs. Median travel distance was 22.8 miles (interquartile range 8.6-54.8 miles, range 0-2,688.9 miles). Median age was 75 years for all distance quintiles. Patients traveling farther were more likely to be female (26.8% in quintile 5 [Q5] vs. 19.9% in Q1, P < 0.001) and to have had a prior aortic surgery (20.8% for Q5 vs. 5.9% for Q1, P < 0.001). Patients traveling farther had higher index procedural costs, with adjusted odds ratio (OR) 2.34 (95% confidence interval [CI] 1.86-2.94, P < 0.0001) of being in the highest cost tertile versus lowest for patients in Q5 vs. Q1. For patients with ≥ 1-year follow-up, those traveling farther had higher imaging costs, with adjusted Q5 OR 1.55 (95% CI 1.22-1.95, P = 0.0002), and comprehensive first-year costs, with adjusted Q5 OR 2.06 (95% CI 1.57-2.70, P < 0.0001). In contrast, patients traveling farther had similar numbers of reinterventions and imaging studies postoperatively. CONCLUSIONS: Patients traveling farther for complex aortic surgery have higher procedural costs, postoperative imaging costs, and comprehensive first-year costs. These patients should be targeted for increased care coordination for improved outcomes and healthcare system burden.

High incidence of type 2 endoleak and low associated adverse events in the Vascular Quality Initiative linked to Medicare claims.

INTRODUCTION: Type 2 endoleak (T2EL) is the most common adverse finding on postoperative surveillance after endovascular aortic aneurysm repair (EVAR). A low rate of aneurysm-related mortality with T2EL has been established. However, the optimal management strategy and the efficacy of reintervention remain controversial. This study used data from the Vascular Quality Initiative linked to Medicare claims (VQI-Medicare) to evaluate T2LE in a real-world cohort. METHODS: This retrospective review of EVAR procedures in VQI-Medicare included patients undergoing their first EVAR procedure between 2015 and 2017. Patients with an endoleak other than T2EL on completion angiogram and those without VQI imaging follow-up were excluded. Patients without Medicare part A or part B enrollment at the time of the procedure or without 1-year complete Medicare follow-up data were also excluded. The exposure variable was T2EL, defined as any branch vessel flow detected within the first postoperative year. Outcomes of interest were mortality, reintervention, T2EL-related reintervention, post-EVAR imaging, and T2EL behavior including spontaneous resolution, aneurysm sac regression, and resolution after reintervention. The association of prophylactic branch vessel embolization (PBE) with T2EL resolution and aneurysm sac regression was also evaluated. RESULTS: In a final cohort of 5534 patients, 1372 (24.7%) had an identified T2EL and 4162 (75.2%) did not. The median age of patients with and without T2EL was 77 and 75 years, respectively. There were no differences in mortality, imaging, reintervention, or T2EL-related reintervention at 3 years after the procedure for patients with T2EL. The aneurysm sac diameter decreased by 4 mm (range: 9-0 mm decrease) in the total cohort. Patients with inferior mesenteric artery-based T2EL had the smallest decrease in aneurysm diameter (median 1 mm decrease compared with 1.5 mm for accessory renal artery-based T2EL, 2 mm for multiple feeding vessel-based T2EL, and 4 mm for lumbar artery-based T2EL; P < .001). Spontaneous resolution occurred in 73.7% of patients (n = 809). T2ELs with evidence of multiple feeding vessels were associated with the lowest rate of spontaneous resolution (n = 51, 54.9%), compared with those with a single identified feeding vessel of inferior mesenteric artery (n = 99, 60.0%), lumbar artery (n = 655, 77.7%), or accessory renal artery (n = 31, 79.5%) (P < .001). PBE was performed in 84 patients. Patients who underwent PBE and were without detectable T2EL after EVAR had the greatest rate of sac regression at follow-up (7 mm decrease) compared with baseline. CONCLUSIONS: T2EL after EVAR is associated with high rates of spontaneous resolution, low rates of aneurysm sac growth, and no evidence of increased early mortality or reintervention. PBE in conjunction with EVAR may be indicated in some circumstances.

A Novel Preoperative Risk Assessment Tool to Identify Patients at Risk of Contrast-Associated Acute Kidney Injury After Endovascular Abdominal Aortic Aneurysm Repair.

BACKGROUND: Contrast-associated acute kidney injury (CA-AKI) after endovascular abdominal aortic aneurysm repair (EVAR) is associated with mortality and morbidity. Risk stratification remains a vital component of preoperative evaluation. We sought to generate and validate a preprocedure CA-AKI risk stratification tool for elective EVAR patients. METHODS: We queried the Blue Cross Blue Shield of Michigan Cardiovascular Consortium database for elective EVAR patients and excluded those on dialysis, with a history of renal transplant, death during procedure, and without creatinine measures. Association with CA-AKI (rise in creatinine > 0.5 mg/dL) was tested using mixed-effects logistic regression. Variables associated with CA-AKI were used to generate a predictive model via a single classification tree. The variables selected by the classification tree were then validated by fitting a mixed-effects logistic regression model into the Vascular Quality Initiative dataset. RESULTS: Our derivation cohort included 7,043 patients, 3.5% of whom developed CA-AKI. After multivariate analysis, age (odds ratio [OR] 1.021, 95% confidence interval [CI] 1.004-1.040), female sex (OR 1.393, CI 1.012-1.916), glomerular filtration rate (GFR) < 30 mL/min (OR 5.068, CI 3.255-7.891), current smoking (OR 1.942, CI 1.067-3.535), chronic obstructive pulmonary disease (OR 1.402, CI 1.066-1.843), maximum abdominal aortic aneurysm (AAA) diameter (OR 1.018, CI 1.006-1.029), and presence of iliac artery aneurysm (OR 1.352, CI 1.007-1.816) were associated with increased odds of CA-AKI. Our risk prediction calculator demonstrated that patients with a GFR < 30 mL/min, females, and patients with a maximum AAA diameter of > 6.9 cm are at a higher risk of CA-AKI after EVAR. Using the Vascular Quality Initiative dataset (N = 62,986), we found that GFR < 30 mL/min (OR 4.668, CI 4.007-5.85), female sex (OR 1.352, CI 1.213-1.507), and maximum AAA diameter > 6.9 cm (OR 1.824, CI 1.212-1.506) were associated with an increased risk of CA-AKI after EVAR. CONCLUSIONS: Herein, we present a simple and novel risk assessment tool that can be used preoperatively to identify patients at risk of CA-AKI after EVAR. Patients with a GFR < 30 mL/min, maximum AAA diameter > 6.9 cm, and females who are undergoing EVAR may be at risk for CA-AKI after EVAR. Prospective studies are needed to determine the efficacy of our model.