Cost-effectiveness of abdominal aortic aneurysm repair: A systematic review

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.

CEUS versus CT Angiography in the follow-up of abdominal aortic endoprostheses: diagnostic accuracy and activity-based cost analysis

PURPOSE

To evaluate diagnostic accuracy and to perform an activity-based cost analysis of contrast-enhanced ultrasonography (CEUS) compared to computed tomography (CT) during annual surveillance after abdominal aortic aneurysm repair with endovascular procedure (EVAR).

MATERIALS AND METHODS

This retrospective study included 137 patients in post-EVAR follow-up over a 6-year period (average post-operatory follow-up without aneurysm sac volumetric reduction). Sensitivity, specificity, positive predictive values, negative predictive values and accuracy were considered for CEUS using CT angiography (CTA) as reference standard. An activity-based cost analysis was performed to evaluate potential savings due to the introduction of CEUS as an alternative to CT, after the first year of postoperative negative controls.

RESULTS

CEUS reported accuracy, sensitivity, specificity, positive predictive values, negative predictive values of 97.4, 96, 100, 100 and 93.1% in the detection and characterization of endoleaks. CEUS cost was € 84.7, and CTA cost was € 157.77, with a differential cost of € 73.07; using CEUS as an alternative to CT allowed a potential saving of 50.052,95 € during follow-up.

CONCLUSIONS

CEUS is an accurate and cheap imaging method in post-EVAR follow-up patients, and it could be considered as a valid alternative to CTA, after the first year of negative controls, reducing the number of unnecessary CT examinations.

Calculating when elective abdominal aortic aneurysm repair improves survival for individual patients: development of the Aneurysm Repair Decision Aid and economic evaluation

BACKGROUND

Abdominal aortic aneurysm (AAA) repair aims to prevent premature death from AAA rupture. Elective repair is currently recommended when AAA diameter reaches 5.5 cm (men) and 5.0 cm (women). Applying population-based indications may not be appropriate for individual patient decisions, as the optimal indication is likely to differ between patients based on age and comorbidities.

OBJECTIVE

To develop an Aneurysm Repair Decision Aid (ARDA) to indicate when elective AAA repair optimises survival for individual patients and to assess the cost-effectiveness and associated uncertainty of elective repair at the aneurysm diameter recommended by the ARDA compared with current practice.

DATA SOURCES

The UK Vascular Governance North West and National Vascular Database provided individual patient data to develop predictive models for perioperative mortality and survival. Data from published literature were used to model AAA growth and risk of rupture. The cost-effectiveness analysis used data from published literature and from local and national databases.

METHODS

A combination of systematic review methods and clinical registries were used to provide data to populate models and inform the structure of the ARDA. Discrete event simulation (DES) was used to model the patient journey from diagnosis to death and synthesised data were used to estimate patient outcomes and costs for elective repair at alternative aneurysm diameters. Eight patient clinical scenarios (vignettes) were used as exemplars. The DES structure was validated by clinical and statistical experts. The economic evaluation estimated costs, quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratios (ICERs) from the NHS, social care provider and patient perspective over a lifetime horizon. Cost-effectiveness acceptability analyses and probabilistic sensitivity analyses explored uncertainty in the data and the value for money of ARDA-based decisions. The ARDA outcome measures include perioperative mortality risk, annual risk of rupture, 1-, 5- and 10-year survival, postoperative long-term survival, median life expectancy and predicted time to current threshold for aneurysm repair. The primary economic measure was the ICER using the QALY as the measure of health benefit.

RESULTS

The analysis demonstrated it is feasible to build and run a complex clinical decision aid using DES. The model results support current guidelines for most vignettes but suggest that earlier repair may be effective in younger, fitter patients and ongoing surveillance may be effective in elderly patients with comorbidities. The model adds information to support decisions for patients with aneurysms outside current indications. The economic evaluation suggests that using the ARDA compared with current guidelines could be cost-effective but there is a high level of uncertainty.

LIMITATIONS

Lack of high-quality long-term data to populate all sections of the model meant that there is high uncertainty about the long-term clinical and economic consequences of repair. Modelling assumptions were necessary and the developed survival models require external validation.

CONCLUSIONS

The ARDA provides detailed information on the potential consequences of AAA repair or a decision not to repair that may be helpful to vascular surgeons and their patients in reaching informed decisions. Further research is required to reduce uncertainty about key data, including reintervention following AAA repair, and assess the acceptability and feasibility of the ARDA for use in routine clinical practice.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Endovascular aneurysm repair delivery redesign leads to quality improvement and cost reduction

OBJECTIVE

Endovascular aneurysm repair (EVAR) is now a mainstay of therapy for abdominal aortic aneurysm, although it remains associated with significant expense. We performed a comprehensive analysis of EVAR delivery at an academic medical center to identify targets for quality improvement and cost reduction in light of impending health care reform.

METHODS

All infrarenal EVARs performed from April 2011 to March 2012 were identified (N = 127). Procedures were included if they met standard commercial instructions for use guidelines, used a single manufacturer, and were billed to Medicare diagnosis-related group 238 (n = 49). By use of DMAIC (define, measure, analyze, improve, and control) quality improvement methodology (define, measure, analyze, improve, control), targets for EVAR quality improvement were identified and high-yield changes were implemented. Procedure technical costs were calculated before and after process redesign.

RESULTS

Perioperative services and clinic visits were identified as targets for quality improvement efforts and cost reduction. Mean technical costs before the intervention were $31,672, with endograft implants accounting for 52%. Pricing redesign in collaboration with hospital purchasing reduced mean EVAR technical costs to $28,607, a 10% reduction in overall cost, with endograft implants now accounting for 46%. Perioperative implementation of instrument tray redesign reduced instrument use by 32% (184 vs 132 instruments), saving $50,000 annually. Unnecessary clinic visits were reduced by 39% (1.6 vs 1.1 clinic visits per patient) through implementation of a preclinic imaging protocol. There was no difference in mean length of stay after the intervention.

CONCLUSIONS

Comprehensive EVAR delivery redesign leads to cost reduction and waste elimination while preserving quality. Future efforts to achieve more competitive and transparent device pricing will make EVAR more cost neutral and enhance its financial sustainability for health care systems.

Impact of anesthesia technique on the incidence of major complications after open aortic abdominal surgery: a cohort study

STUDY OBJECTIVE

To determine the risk factors of perioperative complications and the impact of intrathecal morphine (ITM) in major vascular surgery.

DESIGN

Retrospective analysis of a prospective cohort.

SETTINGS

Operating room, intensive care unit, and Postanesthesia Care Unit of a university hospital.

MEASUREMENTS

Data from 595 consecutive patients who underwent open abdominal aortic surgery between January 1997 and December 2011 were reviewed. Data were stratified into three groups based on the analgesia technique delivered: systemic analgesia (Goup SA), thoracic epidural analgesia (Group TEA), and intrathecal morphine (Group ITM). Preoperative patient characteristics, perioperative anesthetic and medical interventions, and major nonsurgical complications were recorded.

MAIN RESULTS

Patients managed with ITM (n=248) and those given thoracic epidural analgesia (n=70) required lower doses of intravenous (IV) sufentanil intraoperatively and were extubated sooner than those who received systemic analgesia (n=270). Total inhospital mortality was 2.9%, and 24.4% of patients experienced at least one major complication during their hospital stay. Intrathecal morphine was associated with a lower risk of postoperative morbidity (OR 0.51, 95% CI 0.28 - 0.89), particularly pulmonary complications (OR 0.54, 95% CI 0.31 - 0.93) and renal dysfunction (OR 0.52, 95% CI 0.29 - 0.97). Other predictors of nonsurgical complications were ASA physical status 3 and 4 (OR 1.94, 95% CI 1.07 - 3.52), preoperative renal dysfunction (OR 1.61, 95% CI 1.01 - 2.58), prolonged surgical time (OR 1.78, 95% CI 1.16 - 2.78), and the need for blood transfusion (OR 1.77, 95% CI 1.05 - 2.99).

CONCLUSIONS

This single-center study showed a decreased risk of major nonsurgical complications in patients who received neuraxial analgesia after abdominal aortic surgery.

Meeting the need for regenerative therapies: translation-focused analysis of U.S. regenerative medicine opportunities in cardiovascular and peripheral vascular medicine using detailed incidence data

Cardiac and vascular diseases represent one of the most substantial medical areas for the applications of regenerative medicine. Despite advances in endovascular repair, surgical intervention, and disease management, atherosclerosis and heart failure continue to be prominent health problems. This report analyzes the regenerative medicine treatment opportunities in both cardiovascular and peripheral vascular repair, examining the treatment opportunities for tissue-engineered vascular grafts as well as cell-based therapies. U.S. hospital discharge data were used to generate a detailed estimate of the relative target populations for cardiac and vascular disease. Gap analyses were performed for vascular access, small caliber vascular grafts, and cell-based therapies for revascularization and heart failure. The analysis compared current alternatives, gaps in medical need, and what a tissue-engineered or regenerative alternative should achieve for optimum medical and commercial feasibility. Although the number of coronary bypass grafts vastly outnumbered peripheral grafts, a detailed consideration of re-grafts and the success of first grafts combined with gap analysis (GAP) leads us to conclude that peripheral vascular disease is the more commercially feasible and attractive target opportunity for engineered small caliber grafts for the foreseeable future. Cardiac bypass would need substantial long-term clinical experience, which could be a significant hurdle. Vascular access, often regarded as a first-in-man indication, is an excellent opportunity for an engineered graft as an alternative to arteriovenous fistula that could overcome complications associated with a prosthetic graft. The GAP also suggests that for heart failure, cellular therapies should link near-term changes in repair, such as improvement in cardiac output and reduced scarring with limiting progression of the disease, reducing the need for complex pharmacologic management, and reducing rates of hospitalization. Naturally, researchers must determine where their technology and know-how can be applied most effectively, but it is clear from our analysis that an astute strategy in the use of science and technology will be important to successful translation in this space.

Should endovascular repair be reimbursed for low risk abdominal aortic aneurysm patients? Evidence from ontario, Canada

Background. This paper presents unpublished clinical and economic data associated with open surgical repair (OSR) in low risk (LR) patients and how it compares with EVAR and OSR in high risk (HR) patients with an AAA > 5.5 cm. Design. Data from a 1-year prospective observational study was used to compare EVAR in HR patients versus OSR in HR and LR patients. Results. Between 2003 and 2005, 140 patients were treated with EVAR and 195 with OSR (HR: 52; LR: 143). The 1-year mortality rate with EVAR was statistically lower than HR OSR patients and comparable to LR OSR patients. One-year health-related quality of life was lower in the EVAR patients compared to OSR patients. EVAR was cost-effective compared to OSR HR but not when compared to OSR LR patients. Conclusions. Despite a similar clinical effectiveness, these results suggest that, at the current price, EVAR is more expensive than open repair for low risk patients.

Should the size threshold for elective abdominal aortic aneurysm repair be lowered in the endovascular era? Yes

According to current international guidelines, patients with infrarenal or juxtarenal abdominal aortic aneurysms (AAAs) measuring > or = 5.5 cm should undergo repair to reduce the risk of rupture. The 5.5-cm-diameter threshold is the size when the AAA rupture rate balances the mortality rates of elective open surgical AAA repair (3%). Endovascular AAA repair (EVAR) is associated with lower perioperative mortality and complication rates compared with open surgical repair. This debate addresses the issue whether the current size threshold for elective AAA repair needs to be lowered in the endovascular era. This paper supports the position that the size threshold for AAA repair should be lowered in the endovascular era.

Endovascular Abdominal Aortic Aneurysm Repair (EVAR) Procedures: Counterbalancing the Benefits With the Costs

Endovascular abdominal aortic aneurysm (AAA) repair (EVAR) is associated with lower 30-day mortality rates compared with open repair. Despite that, there are no significant differences in mortality rates between the two procedures at 2 years. On the other hand, EVAR is associated with considerably higher costs compared with open repair. The lack of significant long-term differences between the two procedures together with the substantially higher cost of EVAR may question the appropriateness of EVAR as an alternative to open surgical repair in patients fit for surgery. With several thousands of AAA procedures performed worldwide, the employment of EVAR for the management of all AAAs irrespective of the patient’s surgical risk may hold implications for several national health economies. The lower perioperative mortality and morbidity rates associated with EVAR should thus be counterbalanced against the considerable costs of these procedures.

Failure properties of intraluminal thrombus in abdominal aortic aneurysm under static and pulsating mechanical loads

OBJECTIVES

It has been suggested that mechanical failure of intraluminal thrombus (ILT) could play a key role in the rupture of abdominal aortic aneurysms (AAAs), and in the present study, this hypothesis has been investigated. An in vitro experimental approach has been proposed, which provides layer-specific failure data of ILT tissue under static and pulsatile mechanical loads.

METHODS

In total, 112 bone-shaped test specimens are prepared from luminal, medial, and abluminal layers of eight ILTs harvested during open elective AAA repair. Three different types of mechanical experiments, denoted as control test, ultimate strength test, and fatigue test were performed in Dulbecco's modified eagle's medium (DMEM) supplemented with fetal calf serum, L-ascorbic acid, and antibiotics at 37 degrees C and pH 7.0. In detail, fatigue tests, which are experiments, where the ILT tissue is loaded in pulsatile manner, were carried out at three different load levels with a natural frequency of 1.0 Hz.

RESULTS

ILT's ultimate strength (156.5 kPa, 92.0 kPa, and 47.7 kPa for luminal, medial, and abluminal layers, respectively) and referential stiffness (62.88 kPa, 47.52 kPa, and 41.52 kPa, for luminal, medial, and abluminal layers, respectively) continuously decrease from the inside to the outside. ILT tissue failed within less than 1 hour under pulsatile loading at a load level of 60% ultimate strength, while a load level of about 40% ultimate strength did not cause failure within 13.9 hours.

CONCLUSIONS

ILT tissue is vulnerable against fatigue failure and shows significant decreasing strength with respect to the number of load cycles. Hence, after a reasonable time of pulsating loading ILT's strength is far below its ultimate strength, and when compared with stress predictions from finite element (FE) studies, this indicates the likelihood of fatigue failure in vivo. Failure within the ILT could propagate towards the weakened vessel wall behind it and could initialize AAA failure thereafter.