Most privately insured patients do not receive federally recommended abdominal aortic aneurysm screening.

OBJECTIVE: Since 2005, the United States Preventative Services Task Force has recommended abdominal aortic aneurysm (AAA) ultrasound screening for 65- to 75-year-old male ever-smokers. Integrated health systems such as Kaiser Permanente and the Veterans Affairs (VA) health care system report 74% to 79% adherence, but compliance rates in the private sector are unknown. METHODS: The IBM Marketscan Commercial and Medicare Supplemental databases (2006-2017) were queried for male ever-smokers continuously enrolled from age 65 to 75 years. Exclusion criteria were previous history of AAA, connective tissue disorder, and aortic surgery. Patients with abdominal computed tomographic or magnetic resonance imaging from ages 65 to 75 years were also excluded. Screening was defined as a complete abdominal, retroperitoneal, or aortic ultrasound. A logistic mixed-effects model utilizing state as a random intercept was used to identify patient characteristics associated with screening. RESULTS: Of 35,154 eligible patients, 13,612 (38.7%) underwent screening. Compliance varied by state, ranging from 24.4% in Minnesota to 51.6% in Montana (P < .05). Screening activity increased yearly, with 0.7% of screening activity occurring in 2008 vs 22.2% in 2016 (P <.05). In a logistic mixed-effects model adjusting for state as a random intercept, history of hypertension (odds ratio [OR], 1.07; 95% confidence interval [CI], 1.03-1.13), coronary artery disease (OR, 1.17; 95% CI, 1.10-1.22), congestive heart failure (OR, 1.14; 95% CI, 1.01-1.22), diabetes (OR, 1.1; 95% CI, 1.06-1.16), and chronic kidney disease (OR, 1.4; 95% CI, 1.24-1.53) were associated with screening. Living outside of a census-designated metropolitan area was negatively associated with screening (OR, 0.92; 95% CI, 0.87-0.97). CONCLUSIONS: In a private claims database representing 250 million claimants, 38.7% of eligible patients received United States Preventative Services Task Force-recommended AAA screening. Compliance was nearly one-half that of integrated health systems and was significantly lower for patients living outside of metropolitan areas. Efforts to improve early detection of AAA should include targeting non-metropolitan areas and modifying Medicare reimbursement and incentivization strategies to improve guideline adherence.

Cost-effectiveness of computed tomography versus ultrasound-based surveillance following endovascular aortic repair of intact infrarenal abdominal aortic aneurysms.

BACKGROUND: While Society for Vascular Surgery guidelines recommend computed tomography angiography (CTA) or ultrasound for surveillance following infrarenal endovascular aortic repair (EVAR), there is a lack of consensus regarding optimal timing and modalities. We hypothesized that ultrasound-based approaches would be more cost-effective and developed a cost-effectiveness analysis to estimate the lifetime costs and outcomes of various strategies. METHODS: We developed a decision tree with nested Markov models to compare five surveillance strategies: yearly CTA, yearly CDU, yearly CEU, CTA at first year followed by CDU, and CTA at first year followed by CEU. The model accounted for differential sensitivity, specificity, and risk of acute kidney injury after CTA, and was implemented on a monthly cycle with a willingness-to-pay threshold of $50,000 per quality-adjusted life year (QALY) and 3% annual discounting. RESULTS: Under base case assumptions, the CTA-CDU strategy was cost effective with a lifetime cost of $77950 for 7.74 QALYs. In sensitivity analysis, the CTA-CDU approach remained cost-effective when CEU specificity was less than 95%, and risk of acute kidney injury following CTA was less than 20%. At diagnostic sensitivities below 75% for CEU and 55% for CDU, a yearly CTA strategy maximized QALYs. CONCLUSIONS: A hybrid strategy in which CTA is performed in the first year and CDU is performed annually thereafter is the most cost-effective strategy for infrarenal EVAR surveillance in patients with less than a 20% risk of contrast-induced nephropathy. If the sensitivity of CEU and CDU are at the lower end of plausible estimates, a yearly CTA strategy is reasonable. Further research should aim to identify patients who may benefit from alternative surveillance strategies.

Variability in hospital costs for carotid artery revascularization.

OBJECTIVE: The objective of this study was to understand drivers of cost for carotid endarterectomy (CEA) and carotid artery stenting (CAS) and to compare variation in cost among cases performed by vascular surgery (VS) with other services (OSs). METHODS: We collected internal hospital claims data for CEA and CAS between September 2013 and August 2015 and performed a financial analysis of all hospital costs including room accommodations, medications, medical and surgical supplies, imaging, and laboratory tests. Cases were stratified by presence of symptoms and procedure type, and costs of procedures performed by VS were compared with those performed by OSs. RESULTS: The cohort comprised 144 patients (78 asymptomatic, 66 symptomatic; 44 CAS, 100 CEA) receiving unilateral revascularization. VS (24 CAS, 70 CEA) and neurosurgery and neurointerventional radiology services (20 CAS, 30 CEA) performed all procedures. Age (71 ± 9 years vs 70 ± 11 years; P = .8) and length of stay (1.7 ± 2.1 days vs 2.2 ± 2.4 days; P = .73) were similar for VS and OSs. Symptoms were present before revascularization for 46% and were more commonly treated by OSs (78% vs 29%; P < .001). Case mix index was similar after stratifying by symptoms (asymptomatic, 1.28 ± 0.35 vs 1.39 ± 0.42 [P = .5]; symptomatic, 1.66 ± 0.73 vs 1.82 ± 0.81 [P = .9]). The largest cost components were operating room (OR)-related costs, beds, and supplies, together accounting for 76% of costs. Asymptomatic patients had 37% lower average hospital costs. For asymptomatic CAS, average index hospitalization cost was 17% less for VS compared with OSs because of 78% lower intensive care unit costs, 44% lower OR-related costs, 40% lower medication costs, and 24% lower cardiac testing costs. VS had 22% higher supply costs. For asymptomatic CEA, average index hospitalization costs were 22% lower for VS, driven by lower OR-related costs (28%), medications (28%), imaging (62%), and neurointerventional monitoring (64%). Costs were 38% higher for CAS vs CEA. For symptomatic CAS, costs were similar for both groups. For symptomatic CEA, total costs were 14% lower for VS compared with OSs, driven by 25% lower OR-related costs, 62% lower neurointerventional monitoring, 20% step-down beds, and 28% lower supply costs (and counterbalanced by 117% higher intensive care unit costs). CONCLUSIONS: VS average hospital costs were lower for asymptomatic CAS and all CEAs compared with OSs. Drivers of higher cost appear to be attributed to variation in physicians' practice as well as patients' complexity, affording an opportunity to reduce cost by establishing standard practices when appropriate.

Episode-based cost reduction for endovascular aneurysm repair.

OBJECTIVE: Effective strategies to reduce costs associated with endovascular aneurysm repair (EVAR) remain elusive for many medical centers. In this study, targeted interventions to reduce inpatient EVAR costs were identified and implemented. METHODS: From June 2015 to February 2016, we analyzed the EVAR practice at a high-volume academic medical center to identify, to rank, and ultimately to reduce procedure-related costs. In this analysis, per-patient direct costs to the hospital were compared before (September 2013-May 2015) and after (March 2016-January 2017) interventions were implemented. Improvement efforts concentrated on three categories that accounted for a majority of costs: implants, rooming costs, and computed tomography scans performed during the index hospitalization. RESULTS: Costs were compared between 141 EVAR procedures before implementation (PRE period) and 47 EVAR procedures after implementation (POST period). Based on data obtained through the Society for Vascular Surgery EVAR Cost Demonstration Project, it was determined that implantable device costs were higher than those at peer institutions. New purchasing strategies were implemented, resulting in a 30.8% decrease in per-case device costs between the PRE and POST periods. Care pathways were modified to reduce use of and costs for computed tomography scans obtained during the index hospitalization. Compared with baseline, per-case imaging costs decreased by 92.9% (P < .001), including a 99.0% (P = .001) reduction in postprocessing costs. Care pathways were also implemented to reduce preprocedural rooming for patients traveling long distances the day before surgery, resulting in a 50% decrease in utilization rate (35.4% PRE to 17.0% POST; P = .021), without having a significant impact on median postprocedural length of stay (PRE, 2 days [interquartile range, 1-11 days]; POST, 2 days [1-7 days]; P = .185). Medication costs also decreased by 38.2% (P < .001) as a hospital-wide effort. CONCLUSIONS: Excessive costs associated with EVAR threaten the sustainability of these procedures in health care organizations. Targeted cost reduction efforts can effectively reduce expenses without compromising quality or limiting patients' access.

Long-term outcomes after repair of symptomatic abdominal aortic aneurysms.

OBJECTIVES: Previous studies have reported increased perioperative mortality of nonruptured symptomatic abdominal aortic aneurysms (Sx-AAA) compared with asymptomatic elective AAA (E-AAA) repairs, but no long-term-outcomes have been reported. We sought to compare long-term outcomes of Sx-AAA and E-AAA after repair at a single academic institution. METHODS: Patients receiving AAA repair for Sx-AAA and E-AAA from 1995 through 2015 were included. Ruptured AAA and suprarenal or thoracoabdominal AAA were excluded. Demographics, comorbidities, and operative approach were collected. Long-term mortality was the primary outcome, determined by chart review or link to Social Security Death Index. Additionally, long-term mortality and reinterventions were compared after groups were matched with nearest neighbor propensity to reduce bias. RESULTS: AAA repair was performed for 1054 E-AAA (383 open repair [36%], 671 endovascular aneurysm repair [EVAR] [64%]), and 139 symptomatic aneurysms (60 open repair [43%], 79 EVAR [57%]). Age (73 years vs 74 years; P = .13) and aneurysm diameter were similar between Sx-AAA and E-AAA (6.0 cm vs 5.8 cm; P = .5). The proportion of women was higher for Sx-AAA (26% vs 16%; P = .003), as was the proportion of non-Caucasians (40% vs 29%; P = .009). After propensity matching, there were no differences between groups for patient characteristics, AAA diameter, treatment modality, or comorbidities, including hypertension, coronary artery disease, congestive heart failure, diabetes, hyperlipidemia, lung disease, diabetes, renal disease, and smoking history. Women were treated for Sx-AAA at significantly smaller aortic diameters; however, compared with men (5.1 cm vs 6.3 cm; P < .001). Perioperative mortality was 5.0% for Sx-AAA and 2.3% for E-AAA (P = .055). By life-table analysis, Sx-AAA had lower 5-year (62% vs 71%) and 10-year (39% vs 51%) survivals (P = .01) compared with E-AAA for the entire cohort. Similar trends were observed for 5-year and 10-year mortality after propensity matching (63% and 40% vs 71% and 52%; P = .05). When stratified by repair type 5-year and 10-year survivals trended lower after open surgery (68% and 42% Sx-AAA vs 84% and 59% E-AAA; P = .08) but not EVAR (59% and 40% Sx-AAA vs 61% and 49% E-AAA; P = .4). Aneurysm-related reinterventions were similar for Sx-AAA and E-AAA (15% vs 14%; P = .8). Reinterventions were more common after EVAR compared with open repair (22% vs 7%, Sx-AAA P = .015; 20% vs 4% E-AAA; P = .007). CONCLUSIONS: Patients with Sx-AAA had lower long-term survival and similar aneurysm-related reinterventions compared with patients with E-AAA undergoing repair. Women also underwent repair for Sx-AAA at a significantly smaller size when compared with men, which emphasizes the role of gender in AAA symptomatology. Differences in long-term survival may be only partially explained by measured patient, aneurysm, and operative factors, and may reflect unmeasured social factors or suggest inherent differences in pathophysiology of Sx-AAAs.

Gaps in preoperative surveillance and rupture of abdominal aortic aneurysms among Medicare beneficiaries.

OBJECTIVE: Screening and surveillance are recommended in the management of small abdominal aortic aneurysms (AAAs). Gaps in surveillance after early diagnosis may lead to unrecognized AAA growth, rupture, and death. This study investigates the frequency and predictors of rupture of previously diagnosed AAAs. METHODS: Data were extracted from Medicare claims for patients who underwent AAA repair between 2006 and 2009. Relevant preoperative abdominal imaging exams were tabulated up to 5 years prior to AAA repair. Repair for ruptured AAAs was compared with repair for intact AAAs for those with an early diagnosis of an AAA, defined as having received imaging at least 6 months prior to surgery. Gaps in surveillance were defined as no image within 1 year of surgery or no imaging for more than a 2-year time span after the initial image. Logistic regression was used to examine independent predictors of rupture despite early diagnosis. RESULTS: A total of 9298 patients had repair after early diagnosis, with rupture occurring in 441 (4.7%). Those with ruptured AAAs were older (80.2 ± 6.9 vs 77.6 ± 6.2 years; P < .001), received fewer images prior to repair (5.7 ± 4.1 vs 6.5 ± 3.5; P = .001), were less likely to be treated in a high-volume hospital (45.4% vs 59.5%; P < .001), and were more likely to have had gaps in surveillance (47.4% vs 11.8%; P < .001) compared with those receiving repair for intact AAAs. After adjusting for medical comorbidities, gaps in surveillance remained the largest predictor of rupture in a multivariate analysis (odds ratio, 5.82; 95% confidence interval, 4.64-7.31; P < .001). CONCLUSIONS: Despite previous diagnosis of AAA, many patients experience rupture prior to repair. Improved mechanisms for surveillance are needed to prevent rupture and ensure timely repair for patients with AAAs.

Late diagnosis of abdominal aortic aneurysms substantiates underutilization of abdominal aortic aneurysm screening for Medicare beneficiaries.

OBJECTIVE: Abdominal aortic aneurysm (AAA) screening remains largely underutilized in the U.S., and it is likely that the proportion of patients with aneurysms requiring prompt treatment is much higher compared with well-screened populations. The goals of this study were to determine the proportion of AAAs that required prompt repair after diagnostic abdominal imaging for U.S. Medicare beneficiaries and to identify patient and hospital factors contributing to early vs late diagnosis of AAA. METHODS: Data were extracted from Medicare claims records for patients at least 65 years old with complete coverage for 2 years who underwent intact AAA repair from 2006 to 2009. Preoperative ultrasound and computed tomography was tabulated from 2002 to repair. We defined early diagnosis of AAA as a patient with a time interval of greater than 6 months between the first imaging examination and the index procedure, and late diagnosis as patients who underwent the index procedure within 6 months of the first imaging examination. RESULTS: Of 17,626 patients who underwent AAA repair, 14,948 met inclusion criteria. Mean age was 77.5 ± 6.1 years. Early diagnosis was identified for 60.6% of patients receiving AAA repair, whereas 39.4% were repaired after a late diagnosis. Early diagnosis rates increased from 2006 to 2009 (59.8% to 63.4%; P < .0001) and were more common for intact repair compared with repair after rupture (62.9% vs 35.1%; P < .0001) and for women compared with men (66.3% vs 59.0%; P < .0001). On multivariate analysis, repair of intact vs ruptured AAAs (odds ratio, 3.1; 95% confidence interval, 2.7-3.6) and female sex (odds ratio, 1.4; 95% confidence interval, 1.3-1.5) remained the strongest predictors of surveillance. Although intact repairs were more likely to be diagnosed early, over one-third of patients undergoing repair for ruptured AAAs received diagnostic abdominal imaging greater than 6 months prior to surgery. CONCLUSIONS: Despite advances in screening practices, significant missed opportunities remain in the U.S. Medicare population for improving AAA care. It remains common for AAAs to be diagnosed when they are already at risk for rupture. In addition, a significant proportion of patients with early imaging rupture prior to repair. Our findings suggest that improved mechanisms for observational management are needed to ensure optimal preoperative care for patients with AAAs.

Cost impact of extension cuff utilization during endovascular aneurysm repair.

BACKGROUND: Modular stent-graft systems for endovascular aneurysm repair (EVAR) most often require two to three components, depending on the device. Differences in path lengths and availability of main body systems often require additional extensions for appropriate aneurysm exclusion. These additional devices usually result in added expenses and can affect the financial viability of an EVAR program within a hospital. The purpose of this study was to analyze the use of extensions during EVAR, focusing on incidence, clinical impact, and financial impact, as well as determining the associated cost differences between two- and three-component EVAR device systems. METHODS: We reviewed available clinical data, images, and follow-up of 218 patients (203 males and 15 females, mean age: 74 ± 9 years) who underwent elective EVAR at a single academic center from 2004 to 2007. Patients were divided into two groups: patients undergoing EVAR using the standard number of pieces, that is, no extensions used (group A, n = 98), and those needing proximal or distal extensions during the index procedure (group B, n = 120). RESULTS: Both groups were similar in terms of demographics; preoperative characteristics, including aneurysm morphology; as well as intraoperative, postoperative, and midterm outcomes. Overall, 30-day operative mortality was 1.4%, with a mean follow-up of 24 months. Group A patients underwent repair with two-piece modular devices 41% of the time and three-piece systems 59% of the time, whereas group B patients underwent repair with two-piece modular systems 82% of the time and three-piece modular systems 18% of the time. The number of additional extensions per patient ranged from one to four (median: one piece). There was a 30% cost increase in overall mean device-related cost when using extensions versus the standard number of pieces (group A: $13,220 vs. group B: $17,107, p < 0.01). CONCLUSIONS: Clinical midterm aneurysm-related outcomes after EVAR in patients who required additional extensions was comparable with those treated with the standard number of pieces. An increased number of extensions led to increased costs and could have potentially been minimized with appropriate preoperative planning or device selection. Consideration should be made toward per-case pricing instead of per-piece pricing to further improve cost efficiency without compromising long-term patient outcomes.

Assessment of elastase-induced murine abdominal aortic aneurysms: comparison of ultrasound imaging with in situ video microscopy.

AIMS: The aim of this study was to definitively assess the validity of noninvasive high-frequency ultrasound (US) measurements of aortic luminal diameter (ALD) in a murine model of elastase-induced abdominal aortic aneurysm in comparison with in situ video microscopy (VM). METHODS: C57BL/6 mice underwent transient perfusion of the aorta with either elastase (n = 20: Elastase group) or saline (n = 10: Sham). Unoperated mice (n = 10) were also studied. RESULTS: ALD measurements by US had excellent linear correlation and absolute agreement with that by VM in both Control (unoperated or sham-operated mice) and elastase groups (r = 0.96, intraclass correlation coefficient (ICC) = 0.88 and r = 0.93, ICC = 0.92, resp.). Bland-Altman analysis of US compared with VM measurements in both groups indicated good agreement, however US measurements were slightly but significantly higher than VM measurements in the control group (mean bias 0.039 mm, P < .05). Linear regression analysis revealed excellent correlation between US and VM measurements in both groups. (R² = 0.91 in Control group, R² = 0.85 in elastase group.) The reliability of US measurements was also confirmed by ex vivo histological measurements. CONCLUSIONS: High-frequency US provides reliable ALD measurements in developing murine abdominal aortic aneurysms.

Reduction of postprocedure microemboli following retrospective quality assessment and practice improvement measures for carotid angioplasty and stenting.

OBJECTIVE: We have previously demonstrated a 70% incidence of microemboli on diffusion weighted magnetic resonance imaging (DW-MRI) following carotid angioplasty and stenting (CAS). The purpose of this study is to compare the incidence of microemboli in two distinct time periods when procedural modifications were implemented into a CAS program. METHODS: Following a retrospective quality review of our CAS cohort (n = 27) from November 2004 through April 2006 (period 1), we enrolled patients (n = 20) from May 2006 through February 2008 (period 2) undergoing CAS into a prospective cohort that included obtaining pre- and postprocedure DW-MRI exams. Procedural modifications during period 2 included the preferential use of closed-cell systems (60% vs 0% in period 1), early heparinization at the initiation of arterial access, and elimination of an arch angiogram. The hospital records of these 47 patients were reviewed; symptoms, comorbidities, lesion characteristics, periprocedural information, and postoperative outcomes were collected. The incidence and location of acute, postprocedural microemboli were determined using DW-MRIs. RESULTS: Twenty (74%) CAS patients from period 1 and seven (35%) patients from period 2 demonstrated acute microemboli on postprocedural DW-MRI (P = .02). The mean number of microemboli in period 1 was 4.1 +/- 5.3 vs 1.5 +/- 2.7 during period 2 (P = .04). Two of the 27 patients (7.4%) during period 1 experienced temporary neurologic changes that resolved within 36 hours. None of the patients during period 2 exhibited any neurologic changes. Patient demographics, comorbidities, and presenting symptoms were similar between the two groups except for smoking prevalence, female presence, and obesity (BMI > 30). Period 2 patients when compared with period 1 had more technically challenging anatomy with more calcified lesions (68% vs 27%), longer lesions (15.9 mm vs 8.2 mm), and higher incidence of ulceration (55% vs 27%) (all P < .04). CONCLUSION: Despite successful performance of 47 consecutive CAS procedures without permanent neurologic sequelae, significant reductions in periprocedural embolic events as identified via DW-MRI lesions may be achieved through implementation of quality improvement measures identified through continuous outcome analysis. The long-term neurologic benefits associated with reduced subclinical neurologic events remains to be determined.

Simulation-based endovascular skills assessment: the future of credentialing?

OBJECTIVES: Simulator-based endovascular skills training measurably improves performance in catheter-based image-guided interventions. The purpose of this study was to determine whether structured global performance assessment during endovascular simulation correlated well with trainee-reported procedural skill and prior experience level. METHODS: Fourth-year and fifth-year general surgery residents interviewing for vascular fellowship training provided detailed information regarding prior open vascular and endovascular operative experience. The pretest questionnaire responses were used to separate subjects into low (<20 cases) and moderate (20 to 100) endovascular experience groups. Subjects were then asked to perform a renal angioplasty/stent procedure on the Procedicus Vascular Intervention System Trainer (VIST) endovascular simulator (Mentice Corporation, Gothenburg, Sweden). The subjects' performance was supervised and evaluated by a blinded expert interventionalist using a structured global assessment scale based on angiography setup, target vessel catheterization, and the interventional procedure. Objective measures determined by the simulator were also collected for each subject. A postsimulation questionnaire was administered to determine the subjects' self-assessment of their performance. RESULTS: Seventeen surgical residents from 15 training programs completed questionnaires before and after the exercise and performed a renal angioplasty/stent procedure on the endovascular simulator. The beginner group (n = 8) reported prior experience of a median of eight endovascular cases (interquartile range [IQR], 6.5-17.8; range, 4-20), and intermediate group (n = 9) had previously completed a median of 42 cases (IQR, 31-44; range, 25-89, P = .01). The two groups had similar prior open vascular experience (79 cases vs 75, P = .60). The mean score on the structured global assessment scale for the low experience group was 2.68 of 5.0 possible compared with 3.60 for the intermediate group (P = .03). Scores for subcategories of the global assessment score for target vessel catheterization (P = .02) and the interventional procedure (P = .05) contributed more to the differentiation between the two experience groups. Total procedure time, fluoroscopy time, average contrast used, percentage of lesion covered by the stent, placement accuracy, residual stenosis rates, and number of cine loops utilized were similar between the two groups (P > .05). CONCLUSION: Structured endovascular skills assessment correlates well with prior procedural experience within a high-fidelity simulation environment. In addition to improving endovascular training, simulators may prove useful in determining procedural competency and credentialing standards for endovascular surgeons.