A comparison of reintervention rates after endovascular aneurysm repair between the Vascular Quality Initiative registry, Medicare claims, and chart review

Biodesign: Engineering an aortic endograft explantation tool

Endovascular aortic repair (EVAR) graft failure can be as high as 16% to 30% owing to endoleak, graft migration, or infection, often necessitating explantation, leading to potential morbidity (31%) and mortality (6.3%). Graft prongs frequently tear through the endothelium during explantation, leading to endothelial damage and subsequent fatal bleeding. The current standard of care involves different suboptimal techniques such as the syringe technique in which a cylinder is improvised by cutting a syringe in half and pushed over the graft hooks in a rotating motion, until covered for manual explantation. Because there is no commercially available product to address this shortcoming in graft explantation, we engage in the biodesign process to produce a functional explantation device. We designed and prototyped multiple potential solutions to remove EVAR endografts safely. Silicone tubing with EVAR endografts deployed in the lumen were used to simulate a grafted aorta and test each prototype. Prototypes were compared in their ability to meet design criteria including decrease in graft diameter, prevention of arterial dissection, ease of use, and decrease in procedure time. After determining the single best prototype, surgeon feedback was elicited to iteratively improve the original design. The most effective design uses a tapered lumenal geometry that decreases the EVAR graft diameter and uses stainless steel beads to prevent shear stress to the simulated aorta. A distal grip allows for easy single hand manipulation of the device, while a latching mechanism allows for smooth placement and removal over the endograft. After rigorous prototyping, our device proved feasible and effective for safe EVAR explantation, allowing this procedure to be performed safely.

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

BACKGROUND

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

METHODS

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

RESULTS

A total of 11,199 EVAR patients were examined (mean age 76 ± 7 years; female: 20%; nonelective: 10%). DUS-only imaging surveillance after the first postoperative year was more likely to occur after elective repairs, as well as among older, male patients. Smaller (<6 cm) preoperative AAA diameter and absence of documented concurrent iliac aneurysm was also associated with DUS-only follow-up. Additionally, no endoleak detection on index EVAR completion imaging, as well as a documented >5 mm decrease in AAA sac diameter at 1-year follow-up was more common with DUS-only surveillance protocols. Post-EVAR DUS-only imaging after the first postoperative year had the lowest incidence of reintervention, conversion to open repair, and rupture (as well as the composite reintervention/open conversion/rupture; log-rank P < 0.001 for all). Further, patients receiving exclusively DUS after their first postoperative year had better overall survival (log-rank P < 0.001). These outcome advantages that were associated with DUS-only surveillance compared with CT/MRI-only surveillance after EVAR persisted when controlling for baseline covariates, preoperative AAA diameter, prior aortic surgery history, sac growth, and presence of endoleak (all P < 0.01).

CONCLUSIONS

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

Low energy virtual monochromatic CT with deep learning image reconstruction to improve delineation of endoleaks

AIM

This study aimed to investigate the utility of low-energy virtual monochromatic imaging (VMI) combined with deep-learning image reconstruction (DLIR) in improving the delineation of endoleaks (ELs) after endovascular aortic repair (EVAR) in contrast-enhanced dual-energy CT (DECT).

METHODS

A total of 61 consecutive patients (mean age, 77 years; 46 men) after EVAR who underwent contrast-enhanced DECT were enrolled. Virtual monochromatic 40- and 70-keV images were reconstructed using DLIR (TrueFidelity-H) and conventional hybrid iterative reconstruction (IR). Contrast-to-noise ratio (CNR) of the EL on the venous-phase CT was calculated. Four different reconstructed image series (hybrid IR and DLIR at two energy levels, 40- and 70-keV) were displayed side-by-side and visually assessed for EL conspicuity on a 5-point comparative scale from 0 (best) to -4 (significantly inferior). Two experienced radiologists independently conducted a qualitative evaluation of the CT images.

RESULTS

A total of 30 out of 61 patients presented with an EL. On both 40- and 70-keV images, the CNR of the EL was significantly higher in DLIR than in hybrid IR (40-keV, 14.5 ± 7.3 vs 8.6 ± 4.2, P<0.001; 70-keV, 8.7 ± 4.5 vs 5.5 ± 2.6, P<0.001). The comparative scale of EL conspicuity in the 40-keV DLIR images (Observer1, -0.2 ± 0.4; Observer2, 0.0 ± 0.0) was significantly higher than 40-keV hybrid IR (Observer1, -0.5 ± 0.5; Observer2, -1.0 ± 0.0; P<0.05), 70-keV DLIR (Observer1, -1.8 ± 0.4; Observer2, -2.0 ± 0.0; P<0.001) and 70-keV hybrid IR images (Observer1, -1.8 ± 0.4; Observer2, -2.4 ± 0.5; P<0.001), respectively.

CONCLUSIONS

Using 40-keV VMI in combination with DLIR improves EL delineation after EVAR compared with the 70-keV VMI with hybrid IR or DLIR.

Mid-term results of "off-label" use of the Endurant stentgraft in patients with infrarenal abdominal aortic aneurysms

OBJECTIVES

EVAR is the preferred treatment modality for patients with an infrarenal abdominal aortic aneurysm with suitable anatomy. Each manufacturer of aortic stentgrafts has specific anatomic requirements. In some patients, it is not possible to adhere to the instructions for use, but alternative treatment is also not possible. In these patients, EVAR can be performed outside instructions for use.

METHODS

In this study, all consecutive patients in whom an Endurant II or IIS stentgraft was used between 1 January and 31 December were reviewed. We compared the two patient groups in whom this stentgrafts was used outside and inside instructions for use. Patients with planned adjuvant therapy, for example, chimney procedure or iliac side branches, were excluded.

RESULTS

In 74 of 178 (41.6%) patients, the instructions for use were not adhered. The main reason was pathology of the aortic neck. There were more patients with type IA endoleak, this difference was borderline significant (p = .06). There were more patients with limb occlusion in the early postoperative period, but at the end of the follow-up period, the incidence was comparable. Aneurysm-related mortality and all-cause mortality were comparable in both groups.

CONCLUSION

In this study, real-life experience with the Endurant II and IIS stentgraft is described. Non-adherence with instructions for use was associated with a higher risk of endoleak type IA (p = .06). In the early postoperative period, there were more patients with limb occlusion; this finding was not observed anymore at the end of the follow-up period.

Safety of preoperative branch embolization in patients undergoing evar

The purpose of this systematic review is to evaluate the safety of pre-endovascular abdominal aortic aneurysm repair (EVAR) embolization of aortic side branches - the inferior mesenteric artery and lumbar arteries. Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were followed. A search of MEDLINE and DIMENSION databases identified 9 studies published from 2011 to 2021 that satisfied the inclusion and exclusion criteria. These studies were analyzed to detect the incidence of embolization-related complications. A total of 482 patients underwent preoperative aortic side branch embolization, 30 (6.2%) of whom suffered some kind of minor complication. The only major complication observed was ischemic colitis in 4 (0.82%) patients, two (0.41%) of whom died after bowel resection surgery. Regarding these findings, aortic side branch embolization seems to be a safe procedure, with very low percentages of both minor and major complications.

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.

Sex differences in outcomes among adults undergoing abdominal aortic aneurysm repair

OBJECTIVE

Although the differences in short-term outcomes between male and female patients in abdominal aortic aneurysm (AAA) repair have been well studied, it remains unclear if these sex disparities extend to other long-term adverse outcomes after AAA repair, such as reintervention and late rupture.

METHODS

We performed a retrospective cohort study of 13,007 patients who underwent either endovascular (EVAR) or open AAA repair (OAR) between 2003 and 2015 using data from the Vascular Quality Initiative registries. Eligible patients were linked to fee-for-service Medicare claims to identify late outcomes of rupture and aneurysm-specific reintervention.

RESULTS

The mean age of our cohort was 76 ± 6.7 years, 22% were female, 94% were White, and 77% underwent EVAR. The 10-year rupture incidence was slightly higher for women at 4.8 per 1000 person-years, vs 3.9 for men, but this difference was not statistically significant after risk adjustment (hazard ratio [HR] = 1.13, 95% confidence interval [CI]: 0.74-1.73). Likewise, we found no sex difference in reintervention rates (5.1 vs 4.8 in women per 1000 person-years) even after risk adjustment (HR = 0.95, 95% CI: 0.83-1.09). Regression models suggest effect modification by repair type for reintervention, where women who underwent index EVAR had a higher risk of reintervention than men (HR = 1.08, 95% CI: 0.93-1.26), whereas women who underwent OAR were at a lower risk of reintervention than men (HR = 0.79, 95% CI: 0.58-1.08); however, neither effect reached statistical significance within each subgroup. In addition, we found that the risk of reintervention for women vs men varied by clinical presentation, where women were less likely to undergo reintervention after an elective or symptomatic AAA repair but were more likely to undergo reintervention after a repair for AAA rupture (HR = 1.70, 95% CI: 1.05-2.75).

CONCLUSIONS

Male and female patients who underwent AAA repair had similar rates of reintervention and late aneurysm rupture in the 10 years after their procedure. However, our findings suggest that repair type and clinical presentation may affect the role of sex in clinical outcomes and warrant further exploration in these subgroups.

Long-term Mortality and Reintervention After Repair of Ruptured Abdominal Aortic Aneurysms Using VQI-matched Medicare Claims

OBJECTIVE

The objective of this study was to compare endovascular aortic aneurysm repair (EVAR) versus open aortic repair (OAR) on mortality and reintervention after ruptured infrarenal abdominal aortic aneurysm (rAAA) repair in the Vascular Quality Initiative (VQI).

BACKGROUND

The optimal treatment modality for rAAA remains debated, with little data on long-term comparisons.

METHODS

VQI rAAA repairs (2004-2018) were matched with Medicare claims (VQI-VISION). Primary outcomes were in-hospital and long-term mortality. Secondary outcome was reintervention. Inverse probability weighting was used to adjust for treatment selection, and Cox Proportional Hazards models and negative binomial regressions were used for analysis. Landmark analysis was performed among patients surviving hospital discharge.

RESULTS

Among 1885 VQI/Medicare rAAA patients, 790 underwent OAR, and 1095 underwent EVAR. Median age was 76 years; 73% were male. Inverse probability weighting produced comparable groups. In-hospital mortality was lower after EVAR versus OAR (21% vs 37%, odds ratio: 0.52, 95% CI, 0.4-0.7). One-year mortality rates were lower for EVAR versus OAR [hazard ratio (HR) 0.74, 95% CI, 0.6-0.9], but not statistically different after 1 year (HR: 0.95, 95% CI, 0.8-1.2). This implies additional benefits to EVAR in the short term. Reintervention rates were higher after EVAR than OAR at 2 and 5 years (rate ratio: 1.79 95% CI, 1.2-2.7 and rate ratio:2.03 95% CI, 1.4-3.0), but not within the first year. Reintervention was associated with higher mortality risk for both OAR (HR: 1.66 95% CI, 1.1-2.5) and EVAR (HR: 2.14 95% CI, 1.6-2.9). Long-term mortality was similar between repair types (HR: 0.99, 95% CI, 0.8-1.2).

CONCLUSIONS

Within VQI/Medicare patients undergoing rAAA repair, the perioperative mortality rate favors EVAR but equalizes after 1 year. Reinterventions were more common after EVAR and were associated with higher mortality regardless of treatment.

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.

Impact of Medicaid expansion on outcomes after abdominal aortic aneurysm repair

OBJECTIVE

Lack of insurance has been independently associated with an increased risk of in-hospital mortality after abdominal aortic aneurysm repair, possibly due to worse control of comorbidities and delays in diagnosis and treatment. Medicaid expansion has improved insurance rates and access to care, potentially benefiting these patients. We sought to assess the association between Medicaid expansion and outcomes after abdominal aortic aneurysm repair.

METHODS

A retrospective analysis of Healthcare Cost and Utilization Project State Inpatient Databases data from 14 states between 2012 and 2018 was conducted. The sample was restricted to first-record abdominal aortic aneurysm repairs in adults under age 65 in states that expanded Medicaid on January 1, 2014 (Medicaid expansion group) or had not expanded before December 31, 2018 (non-expansion group). The Medicaid expansion and non-expansion groups were compared between pre-expansion (2012-2013) and post-expansion (2014-2018) time periods to assess baseline demographic and operative differences. We used difference-in-differences multivariable logistic regression adjusted for patient factors, open vs endovascular repair, and standard errors clustered by state. Our primary outcome was in-hospital mortality. Outcomes were stratified by insurance type.

RESULTS

We examined 8995 patients undergoing abdominal aortic aneurysm repair, including 3789 (42.1%) in non-expansion states and 5206 (57.9%) in Medicaid expansion states. Rates of Medicaid insurance were unchanged in non-expansion states but increased in Medicaid expansion states post-expansion (non-expansion: 10.9% to 9.8%; P = .346; expansion: 9.7% to 19.7%; P < .001). One in 10 patients from both non-expansion and Medicaid expansion states presented with ruptured aneurysms, which did not change over time. Rates of open repair decreased in both non-expansion and Medicaid expansion states over time (non-expansion: 25.1% to 19.2%; P < .001; expansion: 25.2% to 18.4%; P < .001). On adjusted difference-in-differences analysis between expansion and non-expansion states pre-to post-expansion, Medicaid expansion was associated with a 1.02% absolute reduction in in-hospital mortality among all patients (95% confidence interval, -1.87% to -0.17%; P = .019). Additionally, among patients who were either on Medicaid or were uninsured (ie, the patients most likely to be impacted by Medicaid expansion), a larger 4.17% decrease in in-hospital mortality was observed (95% confidence interval, -6.47% to -1.87%; P < .001). In contrast, no significant difference-in-difference in mortality was observed for privately insured patients.

CONCLUSIONS

Medicaid expansion was associated with decreased in-hospital mortality after abdominal aortic aneurysm repair among all patients and particularly among patients who were either on Medicaid or were uninsured. Our results provide support for improved access to care for patients undergoing abdominal aortic aneurysm repair through Medicaid expansion.

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.

The impact of completion and follow-up endoleaks on survival, reintervention, and rupture

OBJECTIVE

Endoleaks may be seen at case completion of endovascular abdominal aortic aneurysm repair (EVAR), and the presence of an endoleak may impact outcomes. However, the clinical implications of various endoleaks seen during follow-up is not well-described. Therefore, we studied the impact of endoleaks at completion and at follow-up on mid-term outcomes.

METHODS

We reviewed patients who underwent EVAR from 2003 to 2016 within the Vascular Quality Initiative-Medicare database and identified patients with endoleak at procedure completion and during follow-up, excluding those presenting with rupture. We stratified cohorts by presence of completion and follow-up endoleak subtypes. The primary outcome was 5-year survival, and secondary outcomes included 5-year freedom from reintervention and freedom from rupture. We used Kaplan-Meier estimates and log-rank tests to analyze differences in time-to-event endpoints.

RESULTS

Of 21,745 patients with completion endoleak data, 5085 (23%) had an endoleak. Compared with those without endoleak, those with type I endoleaks had lower 5-year survival (69% vs 75%; P < .001), type II endoleaks had higher survival (79%; P < .001), and types III, IV, and indeterminate were not statistically different (73%, 73%, and 75%, respectively). Freedom from reintervention for types I and III endoleaks were significantly lower than no endoleak cohort (I: 76%; P < .001; III: 72%; P < .001 vs 83%), but freedom from rupture was higher for those with type II and III endoleak (95% and 97% vs 94%; P < .001). Of 14,479 patients with detailed follow-up endoleak data, 2290 (16%) had an endoleak. Compared with those without endoleak, types I and III had significantly lower 5-year survival (I: 80%; P = .002; III: 66%; P < .001 vs 84%), but there were no differences for types II (82%) and indeterminate (77%). Those with any type of follow-up endoleak had lower 5-year freedom from reintervention (I: 70%; P < .001; II: 76%; P = .006; III: 36%; P < .001; indeterminate: 60%; P = .007 vs 84%), and lower freedom from rupture (I: 92%; P < .001; II: 91%; P = .16; III: 88%; P = .01; indeterminate: 90%; P = .11 vs 94%).

CONCLUSIONS

Compared with patients with no endoleak, those with type I completion endoleaks have lower 5-year survival and freedom from reintervention. Patients with types I and III follow-up endoleaks also have lower survival, and any endoleak at follow-up is associated with lower freedom from reintervention and freedom from rupture. These data highlight the importance of careful patient selection and close postoperative follow-up after EVAR, as the presence of endoleaks, specifically type I and III, over time portends worse outcomes.

Association between sex and long-term outcomes of endovascular treatment for peripheral artery disease

BACKGROUND

Endovascular peripheral vascular intervention (PVI) has become the primary revascularization technique used for peripheral artery disease (PAD). Yet, there is limited understanding of long-term outcomes of PVI among women versus men. In this study, our objective was to investigate sex differences in the long-term outcomes of patients undergoing PVI.

METHODS

We performed a cohort study of patients undergoing PVI for PAD from January 1, 2010 to September 30, 2015 using data in the Vascular Quality Initiative (VQI) registry. Patients were linked to fee-for-service Medicare claims to identify late outcomes including major amputation, reintervention, major adverse limb event (major amputation or reintervention [MALE]), and mortality. Sex differences in outcomes were evaluated using cumulative incidence curves, Gray's test, and mixed effects Cox proportional hazards regression accounting for patient and lesion characteristics using inverse probability weighted estimates.

RESULTS

In this cohort of 15,437 patients, 44% (n = 6731) were women. Women were less likely to present with claudication than men (45% vs. 49%, p < 0.001, absolute standardized difference, d = 0.08) or be able to ambulate independently (ambulatory: 70% vs. 76%, p < 0.001, d = 0.14). There were no major sex differences in lesion characteristics, except for an increased frequency of tibial artery treatment in men (23% vs. 18% in women, p < 0.001, d = 0.12). Among patients with claudication, women had a higher risk-adjusted rate of major amputation (hazard ratio [HR] = 1.72, 95% confidence interval [CI]: 1.18-2.49), but a lower risk of mortality (HR = 0.86, 95% CI: 0.75-0.99). There were no sex differences in reintervention or MALE for patients with claudication. However, among patients with chronic limb-threatening ischemia, women had a lower risk-adjusted hazard of major amputation (HR = 0.79, 95% CI: 0.67-0.93), MALE (HR = 0.86, 95% CI: 0.78-0.96), and mortality (HR = 0.86, 95% CI: 0.79-0.94).

CONCLUSION

There is significant heterogeneity in PVI outcomes among men and women, especially after stratifying by symptom severity. A lower overall mortality in women with claudication was accompanied by a higher risk of major amputation. Men with chronic limb-threatening ischemia had a higher risk of major amputation, MALE, and mortality. Developing sex-specific approaches to PVI that prioritizes limb outcomes in women can improve the quality of vascular care for men and women.

Aligning Orifice of the Renal Artery with Fish-Mouth FIXation Technique During Endovascular Aortic Aneurysm Repair for Hostile Neck Anatomy

Background: As the success of endovascular aortic aneurysm repair (EVAR) depends on sufficient proximal fixation of the endograft to the aortic wall, the proximal hostile neck anatomy (HNA) is the major potential treatment-limiting factor in EVAR. The Aorfix endovascular stent graft was designed to operate on highly angulated aortic necks. The Aligning Orifice of the Renal artery with fish-mouth FIXation (AORFIX) technique uniquely and accurately aligns the trough part of the proximal stent end with the orifice of the lower renal artery and is used to optimize the proximal fish-mouth design for maximum proximal seal use. Herein, we aimed to evaluate the usefulness of the AORFIX technique for EVAR in patients with HNA. Methods: Eighty-one consecutive patients who underwent EVAR with the AORFIX technique (+AORFIX technique group, n = 16) and without (standard group, n = 65) were evaluated. The HNA was defined as any of the following: neck angulation ≥60°, neck length ≤15 mm, or neck thrombus or calcification ≥50% of the circumference and conical neck. Results: Each HNA criterion was similar between the two groups. However, the average number of HNA criteria was significantly higher in the +AORFIX technique group (1.9 ± .2 vs. 1.3 ± .1; P < .01). The two groups showed 100% procedural success. The concurrent renal angioplasty and stenting rates (88% vs. 4.6%; P < .01) were significantly higher in the +AORFIX technique group. There were no 30-day deaths in either group and no in-hospital device-related events in the +AORFIX technique group. The median follow-up period was 39 months, and there was no significant between-group difference in freedom from reintervention rate (+AORFIX group vs. standard group, 100% vs. 91.0%; P = .327). Conclusion: EVAR using the AORFIX technique might be useful even in patients with more complex HNA.

Using the Evaluating Devices Using Claims and RegisTry Data (EDUCATe) Plan within the Vascular Implant Surveillance and Interventional Outcomes Network (VISION) to Analyze the Long-Term Outcomes following Endovascular Aortic Aneurysm Repair

BACKGROUND

Implanted devices undergo clinical trials to assess their safety and effectiveness. However, pivotal device trials are limited in their follow-up while postmarket surveillance may incompletely capture late failure. Linking clinical trials to Medicare claims can address these limitations. This study matched patients from investigational device exemption (IDE) clinical trials for endovascular aortic aneurysm repair (EVAR) to Medicare claims-based registry data to compare long-term device outcomes between the 2 sources.

METHODS

Patient-level data from 2 industry-sponsored IDE trials of EVAR devices was provided by a single industry partner. Trial data were matched at the patient level to data from the Vascular Implant Surveillance and Interventional Outcomes Network (VISION), a registry that is a part of the Society for Vascular Surgery Patient Safety Organization. The primary outcomes analyzed were survival and freedom from aneurysm-related reintervention.

RESULTS

Of 159 clinical trial patients, 134 were eligible for claims-based matching and 115 (85.5%) were successfully matched to VISION registry data. For the matched cohort, the Kaplan-Meier estimated survival was 94.8% at 1 year, 82.6% at 3 years, and 68.1% at 5 years. Estimates for freedom from reintervention were 90% at 1 year, 82.4% at 3 years, and 78.1% at 5 years. The estimates for survival were nearly identical between the clinical trial data and that found in the VISION data (log-rank P = 0.89). Freedom from reintervention was similar between the groups, with IDE trial reported freedom from reintervention of 87.3% and 73.3%, compared to VISION of 92.6% and 83% at 1 and 5 years, respectively (log-rank P = 0.13).

CONCLUSIONS

Clinical trial patients who undergo EVAR can be successfully matched to claims-based registry data to improve long-term device surveillance and outcomes reporting. Claims-based results agreed well with IDE trial results for patients through 5 years, supporting the accuracy of claims-based data for longer-term surveillance. Linking clinical trial and claims-based registry data can lead to robust device monitoring.

Endovascular aneurysm repair offers a survival advantage and is cost-effective compared with conservative management in patients physiologically unfit for open repair

OBJECTIVE

The endovascular aneurysm repair-2 (EVAR-2) trial suggested that EVAR in patients unfit for open surgical repair (OSR) failed to provide a significant overall survival advantage compared with conservative management. The aim is to compare survival and cost-effectiveness in patients with poor cardiopulmonary exercise test (CPET) metrics who underwent EVAR or were managed conservatively.

METHODS

A prospective database of all CPETs (1435 patients) performed to assess preoperative fitness for abdominal aortic aneurysm repair was maintained. A total of 350 patients deemed unfit for OSR underwent EVAR or were managed conservatively. A 1:1 propensity-matched analysis incorporating age, gender, anaerobic threshold, and aneurysm size was used to compare survival. Cost-effectiveness analysis was based on the economic model for the National Institute for Health and Care Excellence clinical guideline on abdominal aortic aneurysm treatment.

RESULTS

Propensity matching produced 122 pairs of patients in the EVAR and conservative management groups. The median overall survival for the EVAR group was significantly longer than that for the conservative management group (84 vs 30 months, P < .001). One-, three-, and five-year mortality in the EVAR group was 7%, 40%, and 68%, respectively, compared with 25%, 68%, and 82% in the conservative management group, all P < .001. The increment cost-effectiveness ratio for EVAR was £8023 (US$11,644) per quality-adjusted life year gained compared with £430,602 (US$624,967) in the National Institute for Health and Care Excellence guideline, which is based on EVAR-2 results.

CONCLUSIONS

EVAR offers a survival advantage and is cost-effective in selected patients deemed unfit for OSR based on CPET compared with conservative management.

Use of linked registry claims data for long term surveillance of devices after endovascular abdominal aortic aneurysm repair: observational surveillance study

OBJECTIVE

To evaluate long term outcomes (reintervention and late rupture of abdominal aortic aneurysm) of aortic endografts in real world practice using linked registry claims data.

DESIGN

Observational surveillance study.

SETTING

282 centers in the Vascular Quality Initiative Registry linked to United States Medicare claims (2003-18).

PARTICIPANTS

20 489 patients treated with four device types used for endovascular abdominal aortic aneurysm repair (EVAR): 40.6% (n=8310) received the Excluder (Gore), 32.2% (n=6606) the Endurant (Medtronic), 16.0% (n=3281) the Zenith (Cook Medical), and 11.2% (n=2292) the AFX (Endologix). Given modifications to AFX in late 2014, patients who received the AFX device were categorized into two groups: the early AFX group (n=942) and late AFX group (n=1350) and compared with patients who received the other devices, using propensity matched Cox models.

MAIN OUTCOME MEASURES

Reintervention and rupture of abdominal aortic aneurysm post-EVAR; all patients (100%) had complete follow-up via the registry or claims based outcome assessment, or both.

RESULTS

Median age was 76 years (interquartile range (IQR) 70-82 years), 80.0% (16 386/20 489) of patients were men, and median follow-up was 2.3 years (IQR 0.9-4.1 years). Crude five year reintervention rates were significantly higher for patients who received the early AFX device compared with the other devices: 14.9% (95% confidence interval 13.7% to 16.2%) for Excluder, 19.5% (18.1% to 21.1%) for Endurant, 16.7% (15.0% to 18.6%) for Zenith, and early 27.0% (23.7% to 30.6%) for the early AFX. The risk of reintervention for patients who received the early AFX device was higher compared with the other devices in propensity matched Cox models (hazard ratio 1.61, 95% confidence interval 1.29 to 2.02) and analyses using a surgeon level instrumental variable of >33% AFX grafts used in their practice (1.75, 1.19 to 2.59). The linked registry claims surveillance data identified the increased risk of reintervention with the early AFX device as early as mid-2013, well before the first regulatory warnings were issued in the US in 2017.

CONCLUSIONS

The linked registry claims surveillance data identified a device specific risk in long term reintervention after EVAR of abdominal aortic aneurysm. Device manufacturers and regulators can leverage linked data sources to actively monitor long term outcomes in real world practice after cardiovascular interventions.

Survival, reintervention and surveillance reports: long-term, centre-level evaluation and feedback of vascular interventions

The combination of registry and administrative claims data have facilitated research and quality improvement efforts. Using Vascular Quality Initiative (VQI) registry data and Medicare claims we have generated centre-specific survival, reintervention and surveillance reports which benchmark participating centres' performance to the VQI as a whole and to published guidelines. In 2021, we distributed these reports to 303 participating centres. These reports offer an opportunity for centres to evaluate their performance and identify focus areas for quality improvement work.

Contemporary incidence, outcomes, and survival associated with endovascular aortic aneurysm repair conversion to open repair among Medicare beneficiaries

OBJECTIVE

The widespread application of endovascular abdominal aortic aneurysm repair (EVAR) has ushered in an era of requisite postoperative surveillance and the potential need for reintervention. The national prevalence and results of EVAR conversion to open repair, however, remain poorly defined. The purpose of this analysis was to define the incidence of open conversion and its associated outcomes.

METHODS

The SVS Vascular Quality Initiative EVAR registry linked to Medicare claims via Vascular Implants Surveillance and Interventional Outcomes Network was queried for open conversions after initial EVAR procedures from 2003 to 2016. Cumulative conversion incidence within up to 5 years after EVAR and outcomes after open intervention were determined. Multivariable logistic regressions were used to identify independent predictors of conversion and mortality.

RESULTS

Among 15,937 EVAR patients, 309 (1.9%) underwent an open conversion: 43% (n = 132) early (<30 days) and 57% (n = 177) late (>30 days). The longitudinally observed rate of conversion was constant over time, as well as by geographic region. Independent predictors of conversion included female sex (hazard ratio [HR], 1.49; P < .001), aneurysm diameter or more than 6.0 cm at the time of index EVAR (HR, 1.74; P < .001), nonelective repair (compared with elective presentation: HR, 1.72; P < .001), and aortouni-iliac repairs (HR, 2.19; P < .001). In contrast, adjunctive operative procedures such as endo-anchors or cuff extensions (HR, 0.62; P = .06) were protective against long-term conversion. Both early (HR, 1.6; P < .001) and late (HR, 1.26; P = .07) open conversions were associated with significant 30-day (total cohort, 15%) and 1-year mortality (total cohort, 25%). Patients undergoing open conversion experienced high rates of 30-day readmission (42%) and cardiac (45%), renal (32%), and pulmonary (30%) complications.

CONCLUSIONS

This large, registry-based analysis is among the first to document the incidence and outcomes for open conversion after EVAR in a national cohort with long-term follow-up. Importantly, women, patients with large aneurysms, and complex anatomy, as well as urgent or emergent EVARs are at an increased risk for open conversion. It seems that more conversions are performed in the early postoperative period, despite perceptions that conversion is a delayed phenomenon. In all instances, conversion is associated with significant morbidity and mortality and highlights the importance of appropriate patient selection at the time of index EVAR.

Endovascular versus open repair in patients with abdominal aortic aneurysm: a claims-based data analysis in Japan

Objectives

Endovascular aortic repair (EVAR) evolved through competition with open aortic repair (OAR) as a safe and effective treatment option for appropriately selected patients with abdominal aortic aneurysm (AAA). Although endoleaks are the most common reason for post-EVAR reintervention, compliance with lifelong regular follow-up imaging remains a challenge.

Design

Retrospective data analysis.

Setting

The Japan Medical Data Center (JMDC), a claims database with anonymous data linkage across hospitals, consists of corporate employees and their families of ≤75 years of age.

Participants

The analysis included participants in the JMDC who underwent EVAR or OAR for intact (iAAA) or ruptured (rAAA) AAA. Patients with less than 6 months of records before the aortic repair were excluded.

Main outcome measures

Overall survival and reintervention rates.

Results

We identified 986 cases (837 iAAA and 149 rAAA) from JMDC with first aortic repairs between January 2015 and December 2020. The number of patients, median age (years (IQR)), follow-up (months) and post-procedure CT scan (times per year) were as follows: iAAA (OAR: n=593, 62.0 (57.0–67.0), 26.0, 1.6, EVAR: n=244, 65.0 (31.0–69.0), 17.0, 2.2), rAAA (OAR: n=110, 59.0 (53.0–59.0), 16.0, 2.1, EVAR: n=39, 62.0 (31.0–67.0), 18.0, 2.4). Reintervention rate was significantly higher among EVAR than OAR in rAAA (15.4% vs 8.2%, p=0.04). In iAAA, there were no group difference after 5 years (7.8% vs 11.0%, p=0.28), even though EVAR had initial advantage. There were no differences in mortality rate between EVAR and OAR for either rAAA or iAAA.

Conclusions

Claims-based analysis in Japan showed no statistically significant difference in 5-year survival rates of the OAR and EVAR groups. However, the reintervention rate of EVAR in rAAA was significantly higher, suggesting the need for regular post-EVAR follow-up with imaging. Therefore, international collaborations for long-term outcome studies with real-world data are warranted.

Decreasing Trends in Reintervention and Readmission After Endovascular Aneurysm Repair in a Multiregional Implant Registry

OBJECTIVES

As endovascular aortic aneurysm repair (EVAR) matures into its third decade, measures such as long-term reintervention and readmission have become a focus of quality improvement efforts. Within a large United States integrated healthcare system, we describe time trends in the rates of long-term reinterventions utilization measures.

METHODS

Data from a US multiregional EVAR registry was used to perform a descriptive study of 3,891 adults who underwent conventional infrarenal EVAR for infrarenal abdominal aortic aneurysm between 2010 to 2019. Three-year follow-up was 96.7%. Outcomes included 1-, 3-, and 5-year graft revision (defined as a procedure involving placement of a new endograft component), secondary interventions (defined as a procedure necessary for maintenance of EVAR integrity, e.g., coil embolization and balloon angioplasty/stenting), conversion to open, interventions for type II endoleaks alone, and 90-day readmission. Crude cause-specific reintervention probabilities were calculated by operative year using the Aalen-Johansen estimator, with death as a competing risk and December 31, 2020 as the study end date.

RESULTS

Excluding interventions for type II endoleak alone, 1-year secondary intervention incidence decreased from 5.9% for EVARs in 2010 to 2.0% in 2019 (p<0.001) and 3-year incidence decreased from 7.2% to 3.6% from 2010 to 2017 (p=0.03). The 3-year incidences of graft revision (mean incidence 3.4%) and conversion to open remained fairly stable (mean incidence 0.6%) over time. The 3-year incidence of interventions for type II endoleak alone also decreased from 3.4% in 2010 to 0.7% in 2017 (p=0.01). 90-day readmission rates decreased from 19.3% for index EVAR in 2010 to 9.2% in 2019 (p=0.03).

CONCLUSIONS

Comprehensive data from a multiregional healthcare system demonstrates decreasing long-term secondary intervention and readmission rates over time in patients undergoing EVAR. These trends are not explained by evolving management of type II endoleaks and suggest improving graft durability, patient selection or surgical technique. Further study is needed to define implant and anatomic predictors of different types of long-term reintervention.

Administrative healthcare data as an addition to the Dutch surgaical aneurysm audit to evaluate mid-term reinterventions following abdominal aortic aneurysm repair: A pilot study

BACKGROUND

The Dutch Surgical Aneurysm Audit (DSAA) is a nationwide mandatory quality registry that evaluates the perioperative outcomes of abdominal aortic aneurysms (AAAs). The DSAA includes perioperative outcomes that occur up to 30 days, but various complications following AAA repair occur after this period. Administrative healthcare data yield the possibility to evaluate later occuring outcomes such as reinterventions, without increasing the registration burden. The aim of this study is to assess the feasibility and the potential benefit of administrative healthcare data to evaluate mid-term reinterventions following intact AAA repair.

METHOD

All patients that underwent primary endovascular aneurysm repair (EVAR) or open surgical repair (OSR) for an intact infrarenal AAA between January 2017 and December 2018 were selected from the DSAA. Subsequently, these patients were identified in a database containing reimbursement data. Healthcare activity codes that refer to reinterventions following AAA repair were examined to assess reinterventions within 12 and 15 months following EVAR and OSR.

RESULTS

We selected 4043 patients from the DSAA, and 2059 (51%) patients could be identified in the administrative healthcare database. Reintervention rates of 10.4% following EVAR and 9.5% following OSR within 12 months (p = 0.719), and 11.5% following EVAR and 10.8% following OSR within 15 months (p = 0.785) were reported.

CONCLUSION

Administrative healthcare data as an addition to the DSAA is potentially beneficial to evaluate mid-term reinterventions following intact AAA repair without increasing the registration burden for clinicians. Further validation is necessary before reliable implementation of this tool is warranted.

Validation of an indirect linkage algorithm to combine registry data with Medicare claims

INTRODUCTION

Linkage of registries to Medicare claims data can help extend follow-up for patients receiving medical devices. This study sought to test and validate an algorithm that does not require patient identifiers to link a national vascular registry and Medicare claims data.

METHODS

We used data from the Vascular Quality Initiative (VQI), a registry capturing data from more than 600 centers on several different vascular procedures and Medicare claims from 2003 to 2018. We restricted to patients aged 65 years and older who had fee-for-service entitlement at the time of the procedure for this study. We performed an indirect linkage to combine VQI with Medicare at the patient level using a sequential algorithm based on patient's date of birth, sex, zip code, procedure date, and procedure facility. We compared this against a gold standard of a cohort directly linked using social security numbers (SSNs). We calculated the matching rate and accuracy overall, and before and after October 2015 when the ICD-10 system was adopted in the US.

RESULTS

A total of 144,045 VQI-Medicare linked patients were in the gold standard cohort. Using the indirect linking algorithm, we matched 133,966 of the 144,045 VQI patients to their Medicare claims (matching rate: 93.0%). Among these, 133,104 patients were correctly matched (matching accuracy: 99.4%). The matching rate was higher when the indirect linkage was implemented in ICD-10 coded data than in ICD-9 coded data (94.0% vs. 92.2%). Accuracy of the indirect linkage remained high for all procedure modules post-ICD-10 coding change (overall 99.4%, range 99.0-99.7%).

CONCLUSION

In this study, we successfully used indirect identifiers to link the VQI to Medicare claims with more than 90% success and more than 99% accuracy. When direct linkage of registry-claims data using SSNs is not possible because of availability, confidentiality, or both, this method for indirect linkage provides a suitable alternative. The matching rate and accuracy help ensure the accuracy of long-term follow-up and the completeness and representativeness of linked databases for relevant research and quality improvement initiatives.

Racial Disparities Associated With Reinterventions After Elective Endovascular Aortic Aneurysm Repair

BACKGROUND

There are substantial racial and socioeconomic disparities underlying endovascular abdominal aortic aneurysm repair (EVAR) in the United States. To date, race-based variations in reinterventions following elective EVAR have not been studied. Here, we aim to examine racial disparities associated with reinterventions following elective EVAR in a real-world cohort.

MATERIALS AND METHODS

We used the Vascular Quality Initiative EVAR dataset to identify all patients undergoing elective EVAR between January 2009 and December 2018 in the United States. We compared the association of race with reinterventions after EVAR and all-cause mortality using Welch two-sample t-tests, multivariate logistic regression, and Cox proportional hazards analyses adjusting for baseline differences between groups.

RESULTS

At median follow-up of 1.1 ± 1.1 y (1.3 ± 1.4 y Black, 1.1 ± 1.1 y White; P = 0.02), a total of 1,164 of 42,481 patients (2.7%) underwent reintervention after elective EVAR, including 2.7% (n = 1,096) White versus 3.2% (n = 68) Black (P = 0.21). Black patients requiring reintervention were more frequently female, more frequently current or former smokers, and less frequently insured by Medicare/Medicaid (P < 0.05). After adjusting for baseline differences, the risk of reintervention after elective EVAR was significantly lower for Black versus White patients (HR 0.74, 95% CI 0.55-0.99; P = 0.04). All-cause mortality was comparable between groups (HR 0.81, 95% CI 0.33-2.00, P = 0.65).

CONCLUSIONS

There are significant differences between Black and White patients in the risk of reintervention after elective EVAR in the United States. The etiology of this difference deserves investigation.

Effect of Abdominal Aortic Aneurysm Size on Mid-Term Mortality After Endovascular Repair

BACKGROUND

Previous studies have suggested that large preoperative AAA size may impact late survival after elective EVAR. It is unclear, however, whether this association applies to patients with smaller AAA between 5.0-5.5 cm, who constitute a substantial portion of patients undergoing elective EVAR. The purpose of this study was to delineate the effect of AAA size between 5.0 and 5.5 cm on mid-term mortality after EVAR by analyzing a large national cohort, the Vascular Quality Initiative (VQI) database.

METHODS

Using the Vascular Quality Initiative (VQI) national database, patients who underwent EVAR for intact AAA between 2003 and 2018 were identified and stratified based on maximal AAA diameter into 3 groups: Group 1 (4.0 cm ≤ AAA <5.0 cm); Group 2 (5.0 cm ≤ AAA < 5.5 cm); and Group 3 (AAA ≥ 5.5 cm). Cox proportional hazard model and propensity score matching method were used to estimate AAA size effect on all-cause mortality at 1, 3, and 5 years after EVAR while adjusting for potential confounders.

RESULTS

The study included 32,398 patients, of whom 81% were men with a mean age of 74. The most common group who underwent EVAR was Group 2 (5.0 cm ≤ AAA < 5.5 cm). Larger AAA size was associated with male sex (75% versus 79% versus 84%, for Groups 1, 2, and 3 respectively; P < 0.0001) and with coronary artery disease (27% versus 29% versus 31%, for Groups 1, 2, and 3 respectively, P< 0.0001); but was negatively associated with active smoking (33% versus 31% versus 30%, for Groups 1, 2, and 3, respectively, P< 0.001). While 10% of the largest and smallest AAA groups (Groups 3 and 1, respectively) were symptomatic, only 5% of patients in Group 2 were symptomatic (P < 0.01). Adjusted Cox proportional hazard modeling revealed that patients in Group 2 were at significantly lower risk of 5-year mortality when compared to patients in Group 3 (HR 0.66, 95% CI 0.61-0.72, P< 0.01), while similar in risk when compared to patients in Group 1 (HR 1.11, 95% CI 0.93-1.32, P= 0.26).

CONCLUSION

Our analysis found that over 40% of EVAR in the national VQI cohort were performed for AAA < 5.5 cm, with the greatest number of patients undergoing EVAR at AAA size 5.0-5.5cm. Patients with AAA size 5.0-5.5 cm had better 5-year survival outcomes than patients with AAA ≥ 5.5 cm, and similar survival to patients with small AAA between 4.0-5.0 cm.

Long-term Reintervention After Endovascular Abdominal Aortic Aneurysm Repair

OBJECTIVE

To describe the long-term reintervention rate after endovascular abdominal aortic aneurysm repair (EVR), and identify factors predicting reintervention.

SUMMARY OF BACKGROUND DATA

EVR is the most common method of aneurysm repair in America, and reintervention after EVR is common. Clinical factors predicting reintervention have not been described in large datasets with long-term follow-up.

METHODS

We studied patients who underwent EVR using the Vascular Quality Initiative registry linked to Medicare claims. Our primary outcome was reintervention, defined as any procedure related to the EVR after discharge from the index hospitalization. We used classification and regression tree modeling to inform a multivariable Cox-regression model predicting reintervention after EVR.

RESULTS

We studied 12,911 patients treated from 2003 to 2015. Mean age was 75.5 ± 7.3 years, 79.9% were male, and 89.1% of operations were elective. The 3-year reintervention rate was 15%, and the 10-year rate was 33%. Five factors predicted reintervention: operative time ≥3.0 hours, aneurysm diameter ≥6.0 cm, an iliac artery aneurysm ≥2.0 cm, emergency surgery, and a history of prior aortic surgery. Patients with no risk factors had a 3-year reintervention rate of 12%, and 10-year rate of 26% (n = 7310). Patients with multiple risk factors, such as prior aortic surgery and emergent surgery, had a 3-year reintervention rate 72%, (n = 32). Modifiable factors including EVR graft manufacturer or supra-renal fixation were not associated with reintervention (P = 0.76 and 0.79 respectively).

CONCLUSIONS

All patients retain a high likelihood of reintervention after EVR, but clinical factors at the time of repair can predict those at highest risk.

Significant aortic neck dilation occurs after repair of juxtarenal aneurysms with fenestrated endovascular aneurysm repair

OBJECTIVE

Aortic neck dilation is a reported mode of failure and can be associated with aneurysm sac expansion after standard endovascular abdominal aortic aneurysm repair (EVAR). Fenestrated EVAR (FEVAR) of the juxtarenal segment increases the seal zone length and is often used to treat this disease progression. However, the frequency and risk factors for neck dilation after FEVAR is unknown.

METHODS

We evaluated 124 consecutive FEVARs performed under an investigational device exemption clinical trial for juxtarenal aneurysms (ClinicalTrials.gov identifier, NCT01538056). The aortic diameter at the level of the superior mesenteric artery (SMA; highest fenestration) and lowest renal artery (lowest fenestration) was assessed from computed tomography angiography preoperatively, at 30 days, and annually thereafter. A subgroup analysis was performed to assess aortic neck dilation by the graft type used, degree of oversizing, infrarenal neck length, effective seal zone length, and aortic diameter at the level of the lowest and highest fenestration. Multivariable analysis was then performed to evaluate for predictors of aortic neck dilation.

RESULTS

Of the 124 patients, 56 had complete anatomic detail and follow-up data available for ≥3 years. Those without preoperative or follow-up data available were excluded. The aortic diameter had increased significantly by 3 years at the level of both the SMA (2.4 mm; P < .01) and the lowest renal artery (3.2 mm; P < .01). When those with and without aortic dilation (>3 mm) were compared, only oversizing differed at the level of the SMA (14% vs 19%; P < .01). At the level of the lowest renal artery, the graft diameter differed (30 mm vs 28 mm; P = .02). However, after adjusted analysis, these differences were not significant. Finally, a subgroup analysis was performed to evaluate aortic dilation over time stratified by anatomic factors and should that aortic dilation occurred across differing aneurysm diameters, percentage of oversizing, graft types, and seal zone lengths.

CONCLUSIONS

Aortic neck dilation in the visceral segment can occur after endovascular repair of juxtarenal aneurysms using FEVAR. Further research is warranted to determine how these changes might affect the long-term outcomes.

Quantitative analysis of dynamic computed tomography angiography for the detection of endoleaks after abdominal aorta aneurysm endovascular repair: A feasibility study

Objectives

To assess the feasibility of quantitative analysis of dynamic computed tomography angiography (dCTA) for the detection of endoleaks in patients who underwent endovascular repair of abdominal aortic aneurysms (EVAR).

Material and methods

Twenty patients scheduled for contrast-enhanced CT angiography (CTA) of the abdominal aorta post-EVAR were prospectively enrolled. All patients received a standard triphasic CTA protocol, followed by an additional dCTA. The dCTA acquisition enabled reconstruction of color-coded maps depicting blood perfusion and a dCTA dataset of the aneurysm sac. Observers assessed the dCTA and dynamic CT perfusion (dCTP) images for the detection of endoleaks, establishing diagnostic confidence based on a modified 5-point Likert scale. An index was calculated for the ratio between the endoleak and aneurysm sac using blood flow for dCTP and Hounsfield units (HU) for dCTA. The Wilcoxon test compared the endoleak index and the diagnostic confidence of the observers.

Results

In total, 19 patients (18 males, median age 74 years [70.5–75.7]) were included for analysis. Nine endoleaks were detected in 7 patients using triphasic CTA as the reference standard. There was complete agreement for endoleak detection between the two techniques on a per-patient basis. Both dCTA and dCTP identified an additional endoleak in one patient. The diagnostic confidence using dCTP for detection of endoleaks was not significantly superior to dCTA (5.0 [5–5] vs. 4.5 [4–5], respectively; p = 0.11); however, dCTP demonstrated superior diagnostic confidence for endoleak exclusion compared to dCTA (1.0 [1–1] vs 1.5 [1.5–1.5], respectively; p <0.01). Moreover, the dCTP endoleak index was significantly higher than the dCTA index (18.5 [10.8–20.5] vs. 3.5 [5–2.7], respectively; p = 0.02).

Conclusions

Quantitative analysis of dCTP imaging can aid in the detection of endoleaks and demonstrates a higher endoleak detection rate than triphasic CTA, as well as a strong correlation with visual assessment of dCTA images.

Preliminary Results of the Outpatient Endovascular and Interventional Society National Registry

Purpose

To present a new outcomes-based registry to collect data on outpatient endovascular interventions, a relatively new site of service without adequate historical data to assess best clinical practices. Quality data collection with subsequent outcomes analysis, benchmarking, and direct feedback is necessary to achieve optimal care.

Materials and Methods

The Outpatient Endovascular and Interventional Society (OEIS) established the OEIS National Registry in 2017 to collect data on safety, efficacy, and quality of care for outpatient endovascular interventions. Since then, it has grown to include a peripheral artery disease (PAD) module with plans to expand to include cardiac, venous, dialysis access, and other procedures in future modules. As a Qualified Clinical Data Registry approved by the Centers for Medicare and Medicaid Services, this application also supports new quality measure development under the Quality Payment Program. All physicians operating in an office-based laboratory or ambulatory surgery center can use the Registry to analyze de-identified data and benchmark performance against national averages. Major adverse events were defined as death, stroke, myocardial infarction, acute onset of limb ischemia, index bypass graft or treated segment thrombosis, and/or need for urgent/emergent vascular surgery.

Results

Since Registry inception in 2017, 251 participating physicians from 64 centers located in 18 states have participated. The current database includes 18,134 peripheral endovascular interventions performed in 12,403 PAD patients (mean age 72.3±10.2 years; 60.1% men) between January 2017 and January 2020. Cases were performed primarily in an office-based laboratory (85.1%) or ambulatory surgery center setting (10.4%). Most frequently observed procedure indications from 16,086 preprocedure form submissions included claudication (59%), minor tissue loss (16%), rest pain (9%), acute limb ischemia (5%), and maintenance of patency (3%). Planned diagnostic procedures made up 12.2% of cases entered, with the remainder indicated as interventional procedures (87.6%). The hospital transfer rate was 0.62%, with 88 urgent/emergent transfers and 24 elective transfers. The overall complication rate for the Registry was 1.87% (n=338), and the rate of major adverse events was 0.51% (n=92). Thirty-day mortality was 0.03% (n=6).

Conclusion

This report describes the current structure, methodology, and preliminary results of OEIS National Registry, an outcomes-based registry designed to collect quality performance data with subsequent outcome analysis, benchmarking, and direct feedback to aid clinicians in providing optimal care.

The financial evolution of endovascular aneurysm repair delivery in contemporary practice

OBJECTIVE

The fiscal impact of endovascular repair (EVR) of aortic aneurysms and the requisite device costs have previously highlighted the tenuous long-term financial sustainability among Medicare beneficiaries. The Centers for Medicare & Medicaid Services have since reclassified EVR remuneration paradigms with new Medicare Severity Diagnosis-Related Groups (MS-DRGs) intended to better address the procedure's cost profile. The impact of this change remains unknown. The purpose of this analysis was to compare EVR-specific costs and revenue among Medicare beneficiaries both before and after this change.

METHODS

All infrarenal EVRs performed in fiscal years (FYs) 2014 and 2015, before the MS-DRG change, and those performed in FYs 2017 and 2018, after the MS-DRG change, were identified using the DRG codes 238 (n = 108) and 269 (n = 84), respectively. We then identified those who were treated according to the instructions for use guidelines with a single manufacturer's device and billed to Medicare (n = 23 in FY14-15; n = 22 in FY17-18). From these cohorts, we determined total procedure technical costs, technical revenue, and net technical margin in conjunction with the hospital finance department. Results were then compared between these two groups.

RESULTS

The two cohorts demonstrated similar demographic profiles (FY14-15 vs FY17-18 cohort: age, 78 years vs 74 years; median length of stay, 1.0 day vs 1.0 day). Mean total technical costs were slightly higher in the FY17-18 group ($24,511 in FY14-15 vs $26,445 in FY17-18). Graft implants continued to account for a significant portion of the total cost, with the device cost accounting for 56% of the total procedure costs in both cohorts. Net revenue was greater in the FY17-18 group by $5800 ($30,698 in FY14-15 vs $36,498 in FY17-18), resulting in an increased overall margin in the FY17-18 group compared with the FY14-15 group ($6188 in FY14-15 vs $10,053 in FY17-18).

CONCLUSIONS

Device costs remain the single greatest cost driver associated with EVR delivery. DRG reclassification of EVR to address total procedure and implant costs appears to better address the requisite associated procedure costs and may thereby better support long-term fiscal sustainability of this procedure for hospitals and health systems alike.

Medicare costs for endovascular abdominal aortic aneurysm treatment in the Vascular Quality Initiative

BACKGROUND

Reintervention after endovascular repair (EVR) of abdominal aortic aneurysms is common. However, the cumulative financial impact of reintervention after EVR on a national scale is poorly defined. Our objective was to describe the cost to Medicare for aneurysm treatment (EVR plus reinterventions) among a cohort of patients with known follow-up for 5 years after repair.

METHODS

We identified patients who underwent EVR within the Vascular Quality Initiative who were linked to their respective Medicare claims file (n = 13,995). We excluded patients who underwent EVR after September 30, 2010, and those who had incomplete Medicare coverage (n = 12,788). The remaining cohort (n = 1207) had complete follow-up until death or 5 years (Medicare data available through September 30, 2015). We then obtained and compiled the corresponding Medicare reimbursement data for the index EVR hospitalization and all subsequent reinterventions.

RESULTS

We studied 1207 Medicare patients who underwent EVR and had known follow-up for reinterventions for 5 years. The mean age was 76.2 years (±7.1 years), 21.6% of patients were female, and 91.1% of procedures were elective. The Kaplan-Meier reintervention rate at 5 years was 18%. Among patients who underwent reintervention, 154 (73.7%) had a single reintervention, 40 (19.1%) had two reinterventions, and 15 (7.2%) had three or more reinterventions. The median cost to Medicare for the index EVR hospitalization was $25,745 (interquartile range, $21,131-$28,774). The median cost for subsequent reinterventions was $22,165 (interquartile range, $17,152-$29,605). The cumulative cost to Medicare of aneurysm treatment (EVR plus reinterventions) increased in a stepwise fashion among patients who underwent multiple reinterventions, with each reintervention being similar in cost to the index EVR.

CONCLUSIONS

The overall cost incurred by Medicare to reimburse for each reintervention after EVR is roughly the same as for the initial procedure itself, meaning that Medicare cost projections would be greater than $100,000 for any individual who undergoes an EVR with three reinterventions. The long-term financial impact of EVR must be considered by surgeons, patients, and healthcare systems alike as these cumulative costs may hinder the fiscal viability of an EVR-first therapeutic approach and highlight the need for judicious patient selection paradigms.

Longitudinal Spending on Endovascular and Open Abdominal Aortic Aneurysm Repair

BACKGROUND

Endovascular repair (EVR) has replaced open surgery as the procedure of choice for patients requiring elective abdominal aortic aneurysm (AAA) repair. Long-term outcomes of the 2 approaches are similar, making the relative cost of caring for these patients over time an important consideration.

METHODS AND RESULTS

We linked Medicare claims to Vascular Quality Initiative registry data for patients undergoing elective EVR or open AAA repair from 2004 to 2015. The primary outcome was Medicare's cumulative disease-related spending, adjusted to 2015 dollars. Disease-related spending included the index operation and associated hospitalization, surveillance imaging, reinterventions (AAA-related and abdominal wall procedures), and all-cause admissions within 90 days. We compared the incidence of disease-related events and cumulative spending at 90 days and annually through 7 years of follow-up. The analytic cohort comprised 6804 EVR patients (median follow-up: 1.85 years; interquartile range: 0.82-3.22 years) and 1889 open repair patients (median follow-up: 2.62 years; interquartile range: 1.13-4.80 years). Spending on index surgery was significantly lower for EVR (median [interquartile range]: $25 924 [$22 280-$32 556] EVR versus $31 442 [$24 669-$40 419] open; P<0.001), driven by a lower rate of in-hospital complications (6.6% EVR versus 38.0% open; P<0.001). EVR patients underwent more surveillance imaging (1.8 studies per person-year EVR versus 0.7 studies per person-year open; P<0.001) and AAA-related reinterventions (4.0 per 100 person-years EVR versus 2.1 per 100 person-years open; P=0.041). Open repair patients had higher rates of 90-day readmission (12.9% EVR versus 17.8% open; P<0.001) and abdominal wall procedures (0.6 per 100 person-years EVR versus 1.5 per 100 person-years open; P<0.001). Overall, EVR patients incurred more disease-related spending in follow-up ($7355 EVR versus $2706 open through 5 years). There was no cumulative difference in disease-related spending between surgical groups by 5 years of follow-up (-$33 EVR [95% CI: -$1543 to $1476]).

CONCLUSIONS

We observed no cumulative difference in disease-related spending on EVR and open repair patients 5 years after surgery. Generalized recommendations about which approach to offer elective AAA patients should not be based on relative cost.

Translating coding lists in administrative claims-based research for cardiovascular procedures

BACKGROUND

To effectively use administrative claims for healthcare research, clinical events must be inferred from coding data according to validated algorithms. In October 2015, the United States transitioned from the International Classification of Diseases Ninth Revision (ICD-9) to the Tenth Revision (ICD-10). We describe our method to derive new ICD-10 codes for outcomes after vascular procedures from our prior, validated ICD-9 codes.

METHODS

We began with validated ICD-9 coding lists known to represent outcomes after lower extremity revascularization, thoracic aortic endograft placement, abdominal aortic aneurysm reintervention, and carotid revascularization. We used the publicly available general equivalence mapping tools to derive corresponding ICD-10 codes for each of the ICD-9 codes in our current lists. The resulting lists were then manually reviewed by multiple authors to ensure clinical relevance for appropriate event detection. Clinically nonrelevant and duplicated codes were removed.

RESULTS

A total of 475 ICD-9 codes were translated to ICD-10 with a 98-fold increase (n = 46,630) in the total number of codes. Overall, we found that 77% of codes (n = 35,833) were either duplicated or not clinically relevant upon manual review. For example, for thoracic aortic endograft placement, 97 ICD-9 codes mapped to 14,661 ICD-10 codes in total. A total of 890 codes were removed as duplicates and 9035 codes were removed during manual clinical review. The resultant, reviewed list contained 4736 ICD-10 codes representing a 49-fold increase from the initial ICD-9 list. Findings were similar across the other procedures studied.

CONCLUSIONS

ICD-10 has expanded the number of codes necessary to describe outcomes after vascular procedures. More than 75% of the codes obtained using the general equivalence mapping database were either duplicated or not clinically relevant. Manual review of codes by researchers with clinical knowledge of the procedures is imperative.

Mortality After Paclitaxel Coated Balloon Angioplasty and Stenting of Superficial Femoral and Popliteal Artery in the Vascular Quality Initiative

BACKGROUND

To compare mortality after treatment of superficial femoral-popliteal artery disease with paclitaxel and nonpaclitaxel devices using a multicenter vascular registry.

METHODS

Patients (N=8376) undergoing endovascular treatment of superficial femoral-popliteal artery disease in the Society for Vascular Surgery Vascular Quality Initiative were studied from October 2016 to December 2017. One-year mortality was compared between 3 groups; plain balloon angioplasty (N=2104) versus paclitaxel-coated balloon angioplasty (N=3543), bare-metal stenting (N= 2045) versus paclitaxel-eluting stents (N=684), and combined paclitaxel versus nonpaclitaxel devices. Mortality rates with hazard ratios (HR) and 95% CI were compared in unadjusted and propensity-matched cohorts and illustrated by Kaplan-Meier analysis with subgroup analysis for intermittent claudication, chronic limb-threatening ischemia, and secondary interventions.

RESULTS

In propensity-matched analyses, mortality was similar after plain balloon angioplasty (12.6%) and paclitaxel-coated balloon angioplasty (9.6%; HR=0.84 [95% CI, 0.66-1.06], P=0.14). In propensity-matched groups, mortality was similar after bare-metal stenting (9.8%) and paclitaxel-eluting stenting (8.8%; HR=0.93 [95% CI, 0.62-1.41], P=0.75). In the combined, matched analysis mortality was significantly lower in the paclitaxel device group (8.5%) compared with the nonpaclitaxel device group (11.5%; HR=0.82 [95% CI, 0.68-0.98], P=0.03). Secondary interventions were similar after nonpaclitaxel (N=1113/4149, 26.8%) and paclitaxel device use (N=1113/4227, 26.3%). For intermittent claudication, mortality was lower after paclitaxel device use (1.6%) compared with nonpaclitaxel devices (4.4%; adjusted HR=0.59 [95% CI, 0.39-0.89], P=0.01). For chronic limb-threatening ischemia, the mortality difference was not significant; paclitaxel (12.8%) versus nonpaclitaxel devices (15.5%; adjusted HR=0.85 [95% CI, 0.72-1.00], P=0.05).

CONCLUSIONS

At 1 year, mortality was similar if not lower after treatment of femoral-popliteal occlusive disease with paclitaxel versus nonpaclitaxel devices. This work highlights the potential use of the Society for Vascular Surgery Vascular Quality Initiative for surveillance of the safety of new peripheral arterial devices.

Five-year reintervention after endovascular abdominal aortic aneurysm repair in the Vascular Quality Initiative

OBJECTIVE

Patients who undergo endovascular abdominal aortic aneurysm repair (EVR) remain at risk for reintervention and rupture. We sought to define the 5-year rate of reintervention and rupture after EVR in the Vascular Quality Initiative (VQI).

METHODS

We identified all patients in the VQI who underwent EVR from 2003 to 2015. We linked patients in the VQI to Medicare claims for long-term outcomes. We stratified patients on baseline clinical and procedural characteristics to identify those at risk for reintervention. Our primary outcomes were 5-year rates of reintervention and late aneurysm rupture after EVR. We assessed these with Kaplan-Meier survival estimation.

RESULTS

We studied 12,911 patients who underwent EVR. The mean age was 75.5 years, 79.9% were male, 3.9% were black, and 89.1% of operations were performed electively. The 5-year rate of reintervention for the entire cohort was 21%, and the 5-year rate of late aneurysm rupture was 3%. Reintervention rates varied across categories of EVR urgency. Patients who underwent EVR electively had the lowest 5-year rate of reintervention at 20%. Those who underwent surgery for symptomatic aneurysms had higher rates of reintervention at 25%. Patients undergoing EVR emergently for rupture had the highest rate of reintervention, 27% at 4 years (log-rank across the three groups, P < .001). Black race and aneurysm size of 6.0 cm or greater were associated with significantly elevated reintervention rates (black, 31% vs white, 20% [log-rank, P < .001]; aneurysm size 6.0 cm or greater, 27% vs all others, <20% [log-rank, P < .001]). There were no significant associations between age or gender and the 5-year rate of reintervention.

CONCLUSIONS

More than one in five Medicare patients undergo reintervention within 5 years after EVR in the VQI; late rupture remains low at 3%. Black patients, those with large aneurysms, and those who undergo EVR urgently and emergently have a higher likelihood of adverse outcomes and should be the focus of diligent long-term surveillance.

Claims-based surveillance for reintervention after endovascular aneurysm repair among non-Medicare patients

OBJECTIVE

Many patients who undergo endovascular aortic aneurysm repair (EVR) also undergo repeat procedures, or reinterventions, to address suboptimal device performance and prevent aneurysm rupture. Quality improvement initiatives measuring reintervention after EVR has focused on fee-for-service Medicare patients. However, because patients aged less than 65 years and those with Medicare Advantage represent an important growing subgroup, we used a novel approach leveraging a state data source that captures patients of all ages and with all types of insurance.

METHODS

We identified patients who underwent EVR (2011-2015) within the Vascular Quality Initiative registry and were also listed in the Statewide Planning and Research Cooperative System all-payer claims database of New York. We linked patients in the Vascular Quality Initiative to their Statewide Planning and Research Cooperative System claims file at the patient level with a 96% match rate. We compared outcomes between fee-for-service Medicare eligible, defined as age 65 or older or on dialysis, versus ineligible patients, defined as those younger than 65 and not on dialysis. Our primary outcome was reintervention. We used Cox proportional hazards regression and propensity score matching for risk adjustment.

RESULTS

We studied 1285 patients with a median follow-up of 16 months (range, 1-57 months). The mean age was 74 years, 79% were male, and 84% of procedures were elective. Nearly one in six patients were not Medicare eligible (14%), and the remainder (86%) were Medicare eligible. Medicare-eligible patients were less likely to be male (77% vs 91%; P < .001), have a history of smoking (79% vs 93%; P < .001), and have a nonelective procedure (15% vs 23%; P = .013). The 3-year Kaplan-Meier rate of reintervention was 21%. We found similar rates of reintervention between Medicare-eligible patients and those who were not (19% vs 20%, log-rank P = .199; unadjusted hazard ratio [HR], 0.75; 95% confidence interval [CI], 0.49-1.16). This finding persisted in both the adjusted and propensity-matched analyses (adjusted HR, 0.82; 95% CI, 0.50-1.34; propensity-matched HR, 0.70; 95% CI, 0.36-1.37).

CONCLUSIONS

Reintervention can be monitored using administrative claims from both Medicare and non-Medicare payers, and serve as an important outcome metric after EVR in patients of all ages. The rate of reintervention seems to be similar between older, Medicare-eligible individuals, and those who are not yet eligible.