Cost-effectiveness of open versus endovascular repair of abdominal aortic aneurysm in the OVER trial

2022 ACC/AHA guideline for the diagnosis and management of aortic disease: A report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease" provides recommendations to guide clinicians in the diagnosis, genetic evaluation and family screening, medical therapy, endovascular and surgical treatment, and long-term surveillance of patients with aortic disease across its multiple clinical presentation subsets (ie, asymptomatic, stable symptomatic, and acute aortic syndromes).

METHODS

A comprehensive literature search was conducted from January 2021 to April 2021, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through June 2022 during the guideline writing process, were also considered by the writing committee, where appropriate.

STRUCTURE

Recommendations from previously published AHA/ACC guidelines on thoracic aortic disease, peripheral artery disease, and bicuspid aortic valve disease have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with aortic disease have been developed. There is added emphasis on the role of shared decision making, especially in the management of patients with aortic disease both before and during pregnancy. The is also an increased emphasis on the importance of institutional interventional volume and multidisciplinary aortic team expertise in the care of patients with aortic disease.

Cost-Effectiveness Analysis of Open Versus Endovascular Revascularization for Chronic Mesenteric Ischemia

BACKGROUND

Recent studies have shown a trend supporting endovascular revascularization (ER) in the treatment of chronic mesenteric ischemia (CMI). However, few studies have compared the cost effectiveness of ER and open revascularization (OR) for this indication. The purpose of this study is to conduct a cost-effectiveness analysis comparing open versus ER for CMI.

METHODS

We built a Markov model with Monte Carlo microsimulation using transition probabilities and utilities from existing literature for CMI patients undergoing OR versus ER. Costs were derived from the hospital perspective using the 2020 Medicare Physician Fee Schedule. The model randomized 20,000 patients to either OR or ER and allowed for 1 subsequent reintervention with 3 other intervening health states: alive, alive with complications, and dead. Quality-adjusted life years (QALYs), costs, and incremental cost-effectiveness ratio (ICER) were analyzed over a 5-year period. One-way sensitivity and probabilistic sensitivity analyses were conducted to study the impact of parameter variability on cost effectiveness.

RESULTS

OR cost $4,532 for 1.03 QALYs while ER cost $5,092 for 1.21 QALYs, leading to an ICER of $3,037 per QALY gained in the ER arm. This ICER was less than our willingness to pay threshold of $100,000. Sensitivity analysis demonstrated that our model was most sensitive to costs, mortality, and patency rates after OR and ER. Probabilistic sensitivity analysis demonstrated ER would be considered cost effective 99% of iterations.

CONCLUSIONS

This study found that while 5-year costs for ER were greater than OR, ER afforded greater QALYs than OR. Although ER is associated with lower long-term patency and higher rates of reintervention, it appears to be more cost effective than OR for the treatment of CMI.

2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease" provides recommendations to guide clinicians in the diagnosis, genetic evaluation and family screening, medical therapy, endovascular and surgical treatment, and long-term surveillance of patients with aortic disease across its multiple clinical presentation subsets (ie, asymptomatic, stable symptomatic, and acute aortic syndromes).

METHODS

A comprehensive literature search was conducted from January 2021 to April 2021, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through June 2022 during the guideline writing process, were also considered by the writing committee, where appropriate. Structure: Recommendations from previously published AHA/ACC guidelines on thoracic aortic disease, peripheral artery disease, and bicuspid aortic valve disease have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with aortic disease have been developed. There is added emphasis on the role of shared decision making, especially in the management of patients with aortic disease both before and during pregnancy. The is also an increased emphasis on the importance of institutional interventional volume and multidisciplinary aortic team expertise in the care of patients with aortic disease.

2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease" provides recommendations to guide clinicians in the diagnosis, genetic evaluation and family screening, medical therapy, endovascular and surgical treatment, and long-term surveillance of patients with aortic disease across its multiple clinical presentation subsets (ie, asymptomatic, stable symptomatic, and acute aortic syndromes).

METHODS

A comprehensive literature search was conducted from January 2021 to April 2021, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through June 2022 during the guideline writing process, were also considered by the writing committee, where appropriate.

STRUCTURE

Recommendations from previously published AHA/ACC guidelines on thoracic aortic disease, peripheral artery disease, and bicuspid aortic valve disease have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with aortic disease have been developed. There is added emphasis on the role of shared decision making, especially in the management of patients with aortic disease both before and during pregnancy. The is also an increased emphasis on the importance of institutional interventional volume and multidisciplinary aortic team expertise in the care of patients with aortic disease.

Cost of Follow Up After Endovascular Abdominal Aortic Aneurysm Repair in Patients With an Initial Post-Operative Computed Tomography Angiogram Without Abnormalities

OBJECTIVE

The Observing a Decade of Yearly Standardised Surveillance in EVAR patients with Ultrasound or CT Scan (ODYSSEUS) study was conducted to assess differences in outcomes of patients with continued or discontinued yearly follow up after endovascular abdominal aortic aneurysm repair (EVAR). Earlier results of this study showed that discontinued follow up was not associated with poor outcomes. Therefore, an incremental cost analysis and budget impact analysis of de-implementation of yearly imaging following EVAR was performed.

METHODS

In total, 1 596 patients from the ODYSSEUS study were included. The expected cost savings were assessed if yearly imaging was reduced in patients with a post-operative computed tomography angiogram without abnormalities made around 30 days after EVAR. Costs were derived from the Dutch costs manual, benchmark cost prices, and literature review. Costs were expressed in euros (€) and displayed at 2019 prices. Sensitivity analysis was performed by varying costs.

RESULTS

A difference of 24% in cost was found between patients with continued and discontinued imaging follow up. The cost per patient was €1 935 in the continued group vs. €1 603 per patient in the discontinued group at five years post-EVAR, with a mean difference of €332 (95% bias corrected and accelerated bootstrap confidence interval -741 to 114). De-implementation of yearly imaging would result in an annual nationwide cost saving of €678 471. Sensitivity analysis with variation in adherence rates, imaging, or secondary intervention costs resulted in a saving of at least €271 388 per year.

CONCLUSION

This study provided an in depth analysis of hospital costs for post-EVAR patients in the Netherlands with a modest impact on the Dutch healthcare budget.

Feasibility and Cost Analysis of Ambulatory Endovascular Aneurysm Repair

PURPOSE

We sought to compare the costs of ambulatory endovascular aneurysm repair (a-EVAR) and inpatient EVAR (i-EVAR) at up to 1-year of follow-up.

MATERIALS AND METHODS

A retrospective cohort study of consecutive patients undergoing elective EVAR between April 2016 and December 2018 at two academic centers. Patients planned for a-EVAR were compared with i-EVAR. Costs at 30 days and 1 year were extracted. These included operating room (OR) use, bed occupancy, laboratory and imaging, emergency department (ED) visits, readmissions, and reinterventions. Baseline characteristics were compared. Multiple regression model was used to identify predictors of increased EVAR costs. Repeated measures analysis of variance (ANOVA) was used to compare cost differences at 30 days and 1 year via an intention-to-treat analysis. Bonferroni post hoc test compared between-group differences. A p value<0.05 was considered statistically significant.

RESULTS

One hundred seventy patients were included. Most underwent percutaneous EVAR (>94%) under spinal anesthesia (>84%). Ambulatory endovascular aneurysm repair was successful in 84% (84/100). Ambulatory endovascular aneurysm repair patients (76±8 years) were younger than i-EVAR (78±9 years). They also had a smaller mean aneurysm diameter (56±6 mm) compared with i-EVAR (59±6 mm). Emergency department visits, readmissions, and reinterventions were similar up to 1 year (all p=NS). Ambulatory endovascular aneurysm repair costs showed a non-statistically significant reduction in total costs at 30 days and 1 year by 27% and 21%, respectively. Patients younger than 85 years and males had a 30-day cost reduction by 34% (p=0.027) and 33% (p=0.035), respectively with a-EVAR.

CONCLUSIONS

Same-day discharge is feasible and successful in selected patients. Patients younger than 85 years and males have a short-term cost benefit with EVAR done in the ambulatory setting without increased complications or reinterventions.

CLINICAL IMPACT

This study shows the overall safety of ambulatory EVAR with proper patient selection. These patient had similar post-intervention complications to inpatients. Same day discharge also resulted in short-term reduction in costs in male patients and patients younger than 85 years.

ANALYSIS OF SPIN IN VASCULAR SURGERY RANDOMIZED CONTROLLED TRIALS WITH NONSIGNIFICANT OUTCOMES

OBJECTIVES

Spin is the manipulation of language that distorts the interpretation of objective findings. The purpose of this study is to describe the characteristics of spin found in statistically nonsignificant randomized controlled trials (RCT) comparing carotid endarterectomy (CEA) to carotid artery stenting (CAS) for carotid stenosis (CS), and endovascular repair (EVAR) to open repair (OR) for abdominal aortic aneurysms (AAA).

METHODS

A search of MEDLINE, EMBASE, and the Cochrane Controlled Register of Trials was performed in June 2020 for studies published describing AAA or CS. All phase three RCTs with nonsignificant primary outcomes comparing OR to EVAR or CEA to CAS were included. Studies were appraised for the characteristics and severity of spin using a validated tool. Binary logistic regression was performed to assess the association of spin grade to (1) funding source (commercial vs non-commercial) and (2) the publishing journal's impact factor.

RESULTS

Thirty-one of 355 articles captured were included for analysis. Spin was identified in nine abstracts (9/18) and 13 main texts (13/18) of AAA articles and seven abstracts (7/13) and ten main texts (10/13) of CS articles. For both AAA and CS articles, spin was most commonly found in the manuscript discussion section, with the most commonly employed strategy being the interpretation of statistically nonsignificant primary results to show treatment equivalence or rule out adverse treatment effects. Increasing journal impact factor was associated with a statistically significant lower likelihood of spin in the study title or abstract conclusion (βOR = 0.96, 95% CI: 0.94 - 0.98, p < 0.01) while no significant association could be found with funding source (βOR = 1.33, 95% CI: 0.30-5.92, p = 0.71).

CONCLUSIONS

A large proportion of statistically nonsignificant RCTs contain interpretations that are inconsistent with their results. These findings should prompt authors and readers to appraise study findings independently and to limit the use of spin in study interpretations.

[Pro Endo: No Need for Open Any More... Surveillance is All Important]

Since its first report in 1991, endovascular aneurysm repair (EVAR) has become an established and preferred treatment modality for many patients. Several randomised controlled trials comparing EVAR and open repair have shown an early survival benefit, lower perioperative morbidity and shorter hospital stay with EVAR. As a result, EVAR has become the most common method of elective repair of BAAs in most vascular centres. Despite its widespread use, there are still subgroups of the patient population for whom the benefit of EVAR has not been clearly demonstrated. The most frequently discussed subgroup in this context is the patient with few risk factors - due to concerns about the durability and need of reinterventions. EVAR can provide durability and long-term survival similar to open repair in these younger patients, as long as the aneurysm anatomy and instructions for use are followed. The evidence on the effects of follow-up on patient survival is currently controversial. With increasing knowledge about the behavior of endoprostheses and factors that influence the complications of the endograft, changes in follow-up protocols have been made. A more patient-specific follow-up strategy and less compliance with a rigorous follow up scheme are required.

Cost-Effectiveness of Endovascular Versus Open Repair of Abdominal Aortic Aneurysm: A Systematic Review

PURPOSE

Abdominal aortic aneurysm (AAA) is a life-threatening condition which, in the absence of increasing diameter or rupture, often remains asymptomatic, and a diameter greater than 5.5 cm requires elective surgical repair. This study aimed to evaluate the cost-effectiveness of endovascular repair (EVAR) versus open surgical repair (OSR) in patients with AAA through a systematic review of published health economics studies.

METHODS

Using a systematic review method, an electronic search was conducted for cost-effectiveness studies published on AAA (both in English and Persian) on PubMed, Embase, ISI/Web of Science (WoS), SCOPUS, Global Health databases, and the national databases of Iran from 1990 to 2020 including the keywords "cost-effectiveness", "endovascular", "open surgical", and "abdominal aortic aneurysms". The quality of the studies was assessed using the Quality of Health Economic Studies (QHES) checklist.

RESULTS

In total, 958 studies were found, of which 16 were eligible for further study. All studies were conducted in developed countries, and quality-adjusted life years (QALY) and life years (LY) were used to measure the outcomes. According to the QHES checklist, most studies were of good quality. In European countries and Canada, EVAR has not been cost-effective, while most studies in the United States regard this technique as a cost-effective intervention. For example, incremental cost-effectiveness ratio (ICER) values ranged from $14,252.12 to $34,446.37 per QALY in the USA, while ICER was €116,600.40 per QALY in Portugal.

CONCLUSION

According to the results, the EVAR technique has been more cost-effective than OSR for high-risk patients, but the need for continuous follow-up, increased costs, and re-intervention over the long term and for low-risk patients has reduced the cost-effectiveness of this method. As the health systems vary among different countries (i.e. quality of care, cost of devices, etc.), and due to the heterogeneity of studies in terms of the follow-up period, time horizon, and threshold, all of which are inherent features of economic evaluation, generalizing the results should be done with much caution, and policymaking must be based on national evidence.

Two-year PAD-related health care costs in patients undergoing lower extremity endovascular revascularization: results from the LIBERTY 360° trial

BACKGROUND

Multiple studies have demonstrated the high economic burden related to the management of lower extremity peripheral artery disease (PAD). This is the first study to examine long-term PAD-related costs among unselected patients undergoing endovascular intervention, and to investigate how clinical and anatomic factors impact cost outcomes over time.

METHODS AND RESULTS

We performed a prospective health economic study alongside the LIBERTY 360° trial (ClinicalTrials.gov; identifier NCT01855412) - a prospective, multi-center study evaluating the long-term outcomes of endovascular revascularization to treat claudication or critical limb ischemia. Costs (2018) were calculated using a combination of standard "bottom-up" cost accounting methods (for index procedures), itemized hospital charges and department level cost-to-charge ratios (for non-procedural hospital resources), national Medicare Severity-Diagnosis Related Group-specific average reimbursements (for follow-up hospitalizations) and Medicare payments (for outpatient/chronic care). Methods for the analysis of censored cost data were used to adjust cost estimates for patients with incomplete follow-up. Independent predictors of cumulative 2-year costs were explored using generalized linear models. A total of 1,189 patients were included (500 Rutherford 2-3, 589 Rutherford 4-5, 100 Rutherford 6). Mean total costs associated with the index procedure hospitalization increased with Rutherford classification ($10,304, $11,418, and $19,403 for Rutherford 2-3, 4-5, and 6, respectively; p < 0.01 in all pairwise comparisons). Mean total 2-year follow-up costs were $11,416, $24,846, and $25,720 for Rutherford 2-3, 4-5, and 6, respectively (p < 0.001 comparing Rutherford 2-3 to the other 2 groups; p = 0.09 comparing Rutherford 4-5 and Rutherford 6). Key predictors of higher cumulative 2-year costs included female sex, pedal lesion location, severe lesion calcification, the presence of one or more chronic total occlusions, the number of wounds present on the target limb at baseline, and Rutherford classification.

CONCLUSIONS

Among patients with symptomatic lower extremity PAD undergoing endovascular revascularization, initial treatment costs and total 2-year costs vary significantly according to clinical and lesion-level characteristics, as well as symptom burden.

Cost effectiveness and the role of the National Institute of Health and Care Excellence (NICE) in interventional radiology

Healthcare expenditure is continually increasing and projected to accelerate in the future, with an increasing proportion being spent on interventional radiology. The role of cost effectiveness studies in ensuring the best allocation of resources is discussed, and the role of National Institute of Health and Care Excellence (NICE) in determining this. Issues with demonstrating cost effectiveness have been discussed, and it has been found that there is significant scope for improving cost effectiveness, with suggestions made for how this can be achieved. In this way, more patients can benefit from better treatment given limited healthcare budgets.

Editor's Choice - A Systemic Evaluation of the Costs of Elective EVAR and Open Abdominal Aortic Aneurysm Repair Implies Cost Equivalence

OBJECTIVE

The suggested high costs of endovascular aneurysm repair (EVAR) hamper the choice of insurance companies and financial regulators for EVAR as the primary option for elective abdominal aortic aneurysm (AAA) repair. However, arguments used in this debate are impeded by time related aspects such as effect modification and the introduction of confounding by indication, and by asymmetric evaluation of outcomes. Therefore, a re-evaluation minimising the impact of these interferences was considered.

METHODS

A comparative analysis was performed evaluating a period of exclusive open repair (OR; 1998-2000) and a period of established EVAR (2010-2012). Data from four hospitals in The Netherlands were collected to estimate resource use. Actual costs were estimated by benchmark cost prices and a literature review. Costs are reported at 2019 prices. A break even approach, defining the costs for an endovascular device at which cost equivalence for EVAR and OR is achieved, was applied to cope with the large variation in endovascular device costs.

RESULTS

One hundred and eighty-six patients who underwent elective AAA repair between 1998 and 2000 (OR period) and 195 patients between 2010 and 2012 (EVAR period) were compared. Cost equivalence for OR and EVAR was reached at a break even price for an endovascular device of €13 190. The main cost difference reflected the longer duration of hospital stay (ward and Intensive Care Unit) of OR (€11 644). Re-intervention rates were similar for OR (24.2%) and EVAR (24.6%) (p = .92).

CONCLUSION

Cost equivalence for EVAR and OR occurs at a device cost of €13 000 for EVAR. Hence, for most routine repairs, EVAR is not costlier than OR until at least the five year follow up.

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.

National temporal trends and determinants of cost of abdominal aortic aneurysm repair

INTRODUCTION

In recent decades, there has been a shift in the management of aortic abdominal aneurysm from open intervention (open aortic aneurysm repair) to an endovascular approach (endovascular aortic aneurysm repair). This shift has yielded clinical as well as socioeconomic reverberations. In our current study, we aim to analyze these effects brought about by the switch to endovascular treatment and to scrutinize the determinants of cost variations between the two treatment modalities.

METHODS

The National (Nationwide) Inpatient Sample database was queried for clinical data ranging from 2001 to 2013 using International Classification of Disease, 9th Revision (ICD-9) codes for open and endovascular aortic repair. Clinical parameters and financial data related to the two treatment modalities were analyzed. Temporal trends of index hospitalization costs were determined. Multivariate linear regression was used to characterize determinants of cost for endovascular aneurysm repair and open abdominal aortic aneurysm repair.

RESULTS

A total of 128,154 aortic repairs were captured in our analysis, including 62,871 open repairs and 65,283 endovascular repairs. Over the assessed time period, there has been a decrease in the cost of elective endovascular aortic aneurysm repair from $34,975.62 to $31,384.90, a $3,590.72 difference (p < 0.01), while the cost of open aortic repair has increased from $37,427.77 to $43,640.79 by 2013, a $6,212.79 increase (p < 0.01). The cost of open aortic aneurysm repair disproportionately increased at urban teaching hospitals, where by 2013, it costs $50,205.59, compared to $34,676.46 at urban nonteaching hospitals, and $34,696.97 at rural institutions. Urban teaching hospitals were found to perform an increasing proportion of complex open aneurysm repairs, involving concomitant renal and visceral bypass procedures. On multivariate analysis, strong determinants of cost increase for both endovascular aortic aneurysm repair and open aortic aneurysm repair are rupture status, prolonged length of stay, occurrence of complications, and the need for disposition to a nursing facility or another acute care institution.

CONCLUSION

As the vascular community has shifted from an open repair of abdominal aortic aneurysm to an endovascular approach, a number of unforeseen clinical and economic effects were noted. We have characterized these ramifications to help guide further clinical decision and resource allocation.

Index and follow-up costs of endovascular abdominal aortic aneurysm repair from the Endurant Stent Graft System Post Approval Study (ENGAGE PAS)

OBJECTIVE

Trials for endovascular aneurysm repair (EVAR) report lower perioperative mortality and morbidity, but also higher costs compared with open repair. However, few studies have examined the subsequent cost of follow-up evaluations and interventions. Therefore, we present the index and 5-year follow-up costs of EVAR from the Endurant Stent Graft System Post Approval Study.

METHODS

From August 2011 to June 2012, 178 patients were enrolled in the Endurant Stent Graft System Post Approval Study de novo cohort and treated with the Medtronic Endurant stent graft system (Medtronic Vascular, Santa Rosa, Calif), of whom 171 (96%) consented for inclusion in the economic analysis and 177 participated in the quality-of-life (QOL) assessment over a 5-year follow-up period. Cost data for the index and follow-up hospitalizations were tabulated directly from hospital bills and categorized by Uniform Billing codes. Surgeon costs were calculated by Current Procedural Terminology codes for each intervention. Current Procedural Terminology codes were also used to calculate imaging and clinic follow-up reimbursement as surrogate to cost based on year-specific Medicare payment rates. Additionally, we compared aneurysm-related versus nonaneurysm-related subsequent hospitalization costs and report EuroQol 5D QOL dimensions.

RESULTS

The mean hospital cost per person for the index EVAR was $45,304 (interquartile range [IQR], $25,932-$44,784). The largest contributor to the overall cost was operating room supplies, which accounted for 50% of the total cost at a mean of $22,849 per person. One hundred patients had 233 additional post index admission inpatient admissions; however, only 32 readmissions (14%) were aneurysm related, with a median cost of $13,119 (IQR, $4570-$24,153) compared with a nonaneurysm-related median cost of $6609 (IQR, $1244-$26,466). Additionally, 32 patients were admitted a total of 37 times for additional procedures after index admission, of which 14 (38%) were aneurysm-related. The median cost of hospitalization for aneurysm-related subsequent intervention was $22,023 (IQR, $13,177-$47,752), compared with a median nonaneurysm-related subsequent intervention cost of $19,007 (IQR, $8708-$33,301). After the initial 30-day visit, outpatient follow-up imaging reimbursement averaged $550 per person per year ($475 for computed tomography scans, $75 for the abdomen), whereas annual office visits averaged $107 per person per year, for a total follow-up reimbursement of $657 per person per year. There were no significant differences in the five EuroQol 5D QOL dimensions at each follow-up compared with baseline.

CONCLUSIONS

Costs associated with index EVAR are driven primarily by cost of operating room supplies, including graft components. Subsequent admissions are largely not aneurysm related; however, cost of aneurysm-related hospitalizations is higher than for nonaneurysm admissions. These data will serve as a baseline for comparison with open repair and other devices.

Does Implant Choice Affect the Episode Cost of Pertrochanteric Hip Fracture for US Veterans?

OBJECTIVE

To investigate an association between a surgeon's choice of a cephalomedullary nail (CMN) or sliding hip screw (SHS) with the cost of treating a pertrochanteric hip fracture.

DESIGN

Multicenter retrospective cohort study.

SETTING

US Veterans Health Administration Sierra Pacific Network.

PATIENTS/PARTICIPANTS

Two hundred ninety-four consecutive US veterans admitted for a principal diagnosis of an OTA/AO 31A-type pertrochanteric hip fracture of a native hip from 2000 to 2015.

INTERVENTION

Internal fixation using a CMN or an SHS.

MAIN OUTCOME MEASUREMENTS

Veterans Administration Health Economic Resource Center average national cost estimate of combined acute and postacute care episode cost, excluding implant cost, normalized to 2015 US dollars by the Consumer Price Index.

RESULTS

Median episode cost was $8223 lower with a CMN than an SHS (95% confidence interval, $5700-$10,746, P < 0.001) after matching on a propensity score for treatment with a CMN based on age, sex, body mass index, Charlson Comorbidity Index, fracture characteristics, study site, and admission year. A subgroup propensity-matched analysis excluding reverse obliquity pertrochanteric fractures was not sufficiently powered to detect a difference in episode cost (β = 0.76, P = 0.311).

CONCLUSIONS

Implant choice significantly affected the episode cost of care of hip fracture at Veterans Health Administration facilities.

LEVEL OF EVIDENCE

Economic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Anaerobic threshold as an independent predictor of mid-term survival following elective endovascular repair of abdominal aortic aneurysm

BACKGROUND

The aim of this study was to examine the value preoperative AT as predictor of postoperative survival in patients who underwent elective EVAR for repair of asymptomatic AAA.

METHODS

Consecutive patients who underwent elective EVAR between 2008 and 2018 were analyzed. Cardiopulmonary exercise testing was performed. Perioperative 30-day mortality was compared between patients who had AT ≥8 mL/kg/min and those with AT<8 mL/kg/min. Risk factors for postoperative survival following EVAR were examined using Cox's regression analysis.

RESULTS

Between 1^st January 2008 and 31^st December 2017, 430 patients underwent elective EVAR (standard device: N.=374, fenestrated/branched: N.=56); their median age was 76 years (range: 53-91 years), median AT was 9.3 (range: 5.4-16.1), and 30-day mortality was 0.9%. These patients were followed up for a median of 1630 days. There was no significant difference in perioperative 30-day mortality between patients who had AT≥8 and those who had AT<8 (χ²=1.56, P=0.22). Age (HR=1.51 [CI: 1.07-1.99], P<0.05) and AT (HR=0.59 [CI: 0.45-0.76], P=0.0003) were predictors of reduced postoperative survival following elective EVAR whereas gender (HR=0.75 [CI: 0.4-1.4], P=0.37), AAA diameter (HR=0.95 [CI: 0.77-1.16], P=0.6), and AAA morphology (HR=1.23 [CI: 0.68-1.76], P=0.95) were not.

CONCLUSIONS

Anaerobic threshold is an independent predictor of prolonged survival following elective EVAR and can be used to identify patients who receive most benefit from elective EVAR.

Optimizing Surveillance and Re-intervention Strategy Following Elective Endovascular Repair of Abdominal Aortic Aneurysms

BACKGROUND

EVAR for abdominal aortic aneurysm has an initial survival advantage over OR, but more frequent complications increase costs and long-term aneurysm-related mortality. Randomized controlled trials of EVAR versus OR have shown EVAR is not cost-effective over a patient's lifetime. However, in the EVAR-1 trial, postoperative surveillance may have been sub-optimal, as the importance of sac growth as a predictor of graft failure was overlooked.

METHODS

Real-world data informed a discrete event simulation model of postoperative outcomes following EVAR. Outcomes observed EVAR-1 were compared with those from 5 alternative postoperative surveillance and re-intervention strategies. Key events, quality-adjusted life years and costs were predicted. The impact of using complication and rupture rates from more recent devices, imaging and re-intervention methods was also explored.

RESULTS

Compared with observed EVAR-1 outcomes, modeling full adherence to the EVAR-1 scan protocol reduced abdominal aortic aneurysm (AAA) deaths by 3% and increased elective re-interventions by 44%. European Society re-intervention guidelines provided the most clinically effective strategy, with an 8% reduction in AAA deaths, but a 52% increase in elective re-interventions. The cheapest and most cost-effective strategy used lifetime annual ultrasound in primary care with confirmatory computed tomography if necessary, and reduced AAA-related deaths by 5%. Using contemporary rates for complications and rupture did not alter these conclusions.

CONCLUSIONS

All alternative strategies improved clinical benefits compared with the EVAR-1 trial. Further work is needed regarding the cost and accuracy of primary care ultrasound, and the potential impact of these strategies in the comparison with OR.

[New developements in endovascular infrarenal aortic aneurysm treatment]

CLINICAL/METHODICAL ISSUE

New technical developments in endovascular aortic repair (EVAR) have broadened the range of patients eligible for minimally invasive aneurysm treatment. Optimization of delivery sheaths and catheters by considerable downsizing of diameters, increase of pushability and stability combined with flexibility are important parameters.

PERFORMANCE

Especially patients characterized by small and tortuous iliac access vessels can nowadays be treated by EVAR. Ease and effectiveness of applicability guarantee safety and quality improvement, which results in better treatment of patients. Progress in stent-graft design with integrated options for repositioning, active positioning and aneurysm sealing facilitate treatment of angulated vessel segments or hitherto unsuitable sealing zones.

PRACTICAL RECOMMENDATIONS

Interventionalists have to be familiar with all available stent-graft materials and techniques. Profound knowledge helps to choose the best material for a patient's individual anatomy, confident application and long-term satisfactory results.

Recent developments and current controversies in short-stay endovascular aneurysm repair

INTRODUCTION

Short stay endovascular aneurysm repair pathways (SS-EVAR) provide potential advantages to both healthcare providers and patients. However, these benefits must be carefully balanced against the inherent risks to patient safety and tariff penalties associated with unplanned readmissions.

EVIDENCE ACQUISITION

A literature review was performed using the databases MEDLINE, Embase and Cochrane Library up until March 2019. Search terms used included "endovascular aneurysm repair," "aneurysm repair," "EVAR," "abdominal aortic aneurysm," "day case," "short stay," "fast track," and "ambulatory."

EVIDENCE SYNTHESIS

Nine relevant articles (including one prior review on the topic) were identified. This early data suggests that SS-EVAR is associated with good patient satisfaction and modest cost savings for healthcare providers. Patient selection, preoperative preparation and supported discharge with early follow-up are essential components of a SS-EVAR pathway. Increasingly, SS-EVAR tends to be delivered via bilateral percutaneous access and loco-regional anesthesia. Over 70% of patients enrolled onto SS-EVAR pathways successfully complete them. Long procedures with excessive blood loss are associated with pathway non-completion. All serious complications occur within 6 hours of the procedure and the mortality (0-1%), morbidity (8-58%) and readmission rates (0-6%) associated with SS-EVAR remains acceptably low. SS-EVAR pathways can be safely and effectively implemented in both teaching and non-teaching hospitals.

CONCLUSIONS

Short-stay EVAR pathways are safe and acceptable to patients. With appropriate selection of motivated patients, successful expedited discharge can be achieved with limited readmissions, thus facilitating increased resource efficiency and cost savings for healthcare providers.

Strategy of endovascular versus open repair for patients with clinical diagnosis of ruptured abdominal aortic aneurysm: the IMPROVE RCT

BACKGROUND

Ruptured abdominal aortic aneurysm (AAA) is a common vascular emergency. The mortality from emergency endovascular repair may be much lower than the 40-50% reported for open surgery.

OBJECTIVE

To assess whether or not a strategy of endovascular repair compared with open repair reduces 30-day and mid-term mortality (including costs and cost-effectiveness) among patients with a suspected ruptured AAA.

DESIGN

Randomised controlled trial, with computer-generated telephone randomisation of participants in a 1 : 1 ratio, using variable block size, stratified by centre and without blinding.

SETTING

Vascular centres in the UK (n = 29) and Canada (n = 1) between 2009 and 2013.

PARTICIPANTS

A total of 613 eligible participants (480 men) with a ruptured aneurysm, clinically diagnosed at the trial centre.

INTERVENTIONS

A total of 316 participants were randomised to the endovascular strategy group (immediate computerised tomography followed by endovascular repair if anatomically suitable or, if not suitable, open repair) and 297 were randomised to the open repair group (computerised tomography optional).

MAIN OUTCOME MEASURES

The primary outcome measure was 30-day mortality, with 30-day reinterventions, costs and disposal as early secondary outcome measures. Later outcome measures included 1- and 3-year mortality, reinterventions, quality of life (QoL) and cost-effectiveness.

RESULTS

The 30-day mortality was 35.4% in the endovascular strategy group and 37.4% in the open repair group [odds ratio (OR) 0.92, 95% confidence interval (CI) 0.66 to 1.28; p = 0.62, and, after adjustment for age, sex and Hardman index, OR 0.94, 95% CI 0.67 to 1.33]. The endovascular strategy appeared to be more effective in women than in men (interaction test p = 0.02). More discharges in the endovascular strategy group (94%) than in the open repair group (77%) were directly to home (p < 0.001). Average 30-day costs were similar between groups, with the mean difference in costs being -£1186 (95% CI -£2997 to £625), favouring the endovascular strategy group. After 1 year, survival and reintervention rates were similar in the two groups, QoL (at both 3 and 12 months) was higher in the endovascular strategy group and the mean cost difference was -£2329 (95% CI -£5489 to £922). At 3 years, mortality was 48% and 56% in the endovascular strategy group and open repair group, respectively (OR 0.73, 95% CI 0.53 to 1.00; p = 0.053), with a stronger benefit for the endovascular strategy in the subgroup of 502 participants in whom repair was started for a proven rupture (OR 0.62, 95% CI 0.43 to 0.89; p = 0.009), whereas aneurysm-related reintervention rates were non-significantly higher in this group. At 3 years, considering all participants, there was a mean difference of 0.174 quality-adjusted life-years (QALYs) (95% CI 0.002 to 0.353 QALYs) and, among the endovascular strategy group, a cost difference of -£2605 (95% CI -£5966 to £702), leading to 88% of estimates in the cost-effectiveness plane being in the quadrant showing the endovascular strategy to be 'dominant'.

LIMITATIONS

Because of the pragmatic design of this trial, 33 participants in the endovascular strategy group and 26 in the open repair group breached randomisation allocation.

CONCLUSIONS

The endovascular strategy was not associated with a significant reduction in either 30-day mortality or cost but was associated with faster participant recovery. By 3 years, the endovascular strategy showed a survival and QALY gain and was highly likely to be cost-effective. Future research could include improving resuscitation for older persons with circulatory collapse, the impact of local anaesthesia and emergency consent procedures.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN48334791 and NCT00746122.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 22, No. 31. See the NIHR Journals Library website for further project information.

Percutaneous Endovascular Aortic Aneurysm Repair for Abdominal Aortic Aneurysm

PURPOSE OF REVIEW

This review discusses the benefits of a completely percutaneous approach to endovascular aortic aneurysm repair (EVAR), and provides an outline as to how this is performed by a multidisciplinary team of cardiologists and cardiovascular surgeons at a quaternary care community hospital.

RECENT FINDINGS

Percutaneous endovascular aortic aneurysm repair (PEVAR) as compared to EVAR utilizing surgical femoral artery exposure is associated with a significant reduction in operation time, length of stay, access site complications, patient discomfort, and procedural cost. Furthermore, PEVAR may be the preferred approach in patients presenting with aneurysm rupture, as the avoidance of general anesthesia has been associated with improved 30-day mortality. Assuming no contraindication based on vascular anatomy, clinical status, or patient preference, these findings suggest that in properly selected patients, PEVAR should be the primary method for abdominal aortic aneurysm repair in both stable and unstable patients.

Direct health costs and clinical outcomes of open surgery in patients with abdominal aortic aneurysm in Spain. The RECAPTA study

OBJECTIVE

Abdominal aortic aneurysm (AAA) is a chronic, progressive disease that often requires surgical repair. This study aimed to assess the healthcare costs and clinical outcomes of open AAA repair in Spain.

METHOD

Observational, retrospective, multicenter study with a one-year follow-up. Healthcare resource use and costs related to the surgical procedure, hospital stay, and follow-up period were assessed.

RESULTS

Ninety patients with asymptomatic AAA who underwent open repair were recruited between 2003 and 2009 at three Spanish hospitals. Four patients (4.44%) died in the first 30 postoperative days. Mean [standard deviation] procedure time was 292.83 [72.10] minutes and mean hospital length of stay was 11.44 days [5.42]. Thirty two patients (35.56%) presented in-hospital complications and three patients (3.45%) underwent re-intervention during follow-up. The mean overall cost per patient during the study period was €21,622.59, of which 42.40% (€9,168.19), 52.08% (€11,261.74), and 5.52% (€1,192.66) corresponded to the surgical procedure, the inpatient stay, and the study follow-up period, respectively.

CONCLUSIONS

Given the economic burden imposed by the treatment of patients admitted with AAA on the Spanish health system, additional efforts comparing the cost of open repair with endovascular treatments are needed to ensure greater efficiency.

Mechanical and geometrical determinants of wall stress in abdominal aortic aneurysms: A computational study

An aortic aneurysm (AA) is a focal dilatation of the aortic wall. Occurrence of AA rupture is an all too common event that is associated with high levels of patient morbidity and mortality. The decision to surgically intervene prior to AA rupture is made with recognition of significant procedural risks, and is primarily based on the maximal diameter and/or growth rate of the AA. Despite established thresholds for intervention, rupture occurs in a notable subset of patients exhibiting sub-critical maximal diameters and/or growth rates. Therefore, a pressing need remains to identify better predictors of rupture risk and ultimately integrate their measurement into clinical decision making. In this study, we use a series of finite element-based computational models that represent a range of plausible AA scenarios, and evaluate the relative sensitivity of wall stress to geometrical and mechanical properties of the aneurysmal tissue. Taken together, our findings encourage an expansion of geometrical parameters considered for rupture risk assessment, and provide perspective on the degree to which tissue mechanical properties may modulate peak stress values within aneurysmal tissue.

The UK EndoVascular Aneurysm Repair (EVAR) randomised controlled trials: long-term follow-up and cost-effectiveness analysis

BACKGROUND

Short-term survival benefits of endovascular aneurysm repair (EVAR) compared with open repair (OR) of intact abdominal aortic aneurysms have been shown in randomised trials, but this early survival benefit is soon lost. Survival benefit of EVAR was unclear at follow-up to 10 years.

OBJECTIVE

To assess the long-term efficacy of EVAR against OR in patients deemed fit and suitable for both procedures (EVAR trial 1; EVAR-1); and against no intervention in patients unfit for OR (EVAR trial 2; EVAR-2). To appraise the long-term significance of type II endoleak and define criteria for intervention.

DESIGN

Two national, multicentre randomised controlled trials: EVAR-1 and EVAR-2.

SETTING

Patients were recruited from 37 hospitals in the UK between 1 September 1999 and 31 August 2004.

PARTICIPANTS

Men and women aged ≥ 60 years with an aneurysm of ≥ 5.5 cm (as identified by computed tomography scanning), anatomically suitable and fit for OR were randomly assigned 1 : 1 to either EVAR (n = 626) or OR (n = 626) in EVAR-1 using computer-generated sequences at the trial hub. Patients considered unfit were randomly assigned to EVAR (n = 197) or no intervention (n = 207) in EVAR-2. There was no blinding.

INTERVENTIONS

EVAR, OR or no intervention.

MAIN OUTCOME MEASURES

The primary end points were total and aneurysm-related mortality until mid-2015 for both trials. Secondary outcomes for EVAR-1 were reinterventions, costs and cost-effectiveness.

RESULTS

In EVAR-1, over a mean of 12.7 years (standard deviation 1.5 years; maximum 15.8 years), we recorded 9.3 deaths per 100 person-years in the EVAR group and 8.9 deaths per 100 person-years in the OR group [adjusted hazard ratio (HR) 1.11, 95% confidence interval (CI) 0.97 to 1.27; p = 0.14]. At 0-6 months after randomisation, patients in the EVAR group had a lower mortality (adjusted HR 0.61, 95% CI 0.37 to 1.02 for total mortality; HR 0.47, 95% CI 0.23 to 0.93 for aneurysm-related mortality; p = 0.031), but beyond 8 years of follow-up patients in the OR group had a significantly lower mortality (adjusted HR 1.25, 95% CI 1.00 to 1.56, p = 0.048 for total mortality; HR 5.82, 95% CI 1.64 to 20.65, p = 0.0064 for aneurysm-related mortality). The increased aneurysm-related mortality in the EVAR group after 8 years was mainly attributable to secondary aneurysm sac rupture, with increased cancer mortality also observed in the EVAR group. Overall, aneurysm reintervention rates were higher in the EVAR group than in the OR group, 4.1 and 1.7 per 100 person-years, respectively (p < 0.001), with reinterventions occurring throughout follow-up. The mean difference in costs over 14 years was £3798 (95% CI £2338 to £5258). Economic modelling based on the outcomes of the EVAR-1 trial showed that the cost per quality-adjusted life-year gained over the patient's lifetime exceeds conventional thresholds used in the UK. In EVAR-2, patients died at the same rate in both groups, but there was suggestion of lower aneurysm mortality in those who actually underwent EVAR. Type II endoleak itself is not associated with a higher rate of mortality.

LIMITATIONS

Devices used were implanted between 1999 and 2004. Newer devices might have better results. Later follow-up imaging declined, particularly for OR patients. Methodology to capture reinterventions changed mainly to record linkage through the Hospital Episode Statistics administrative data set from 2009.

CONCLUSIONS

EVAR has an early survival benefit but an inferior late survival benefit compared with OR, which needs to be addressed by lifelong surveillance of EVAR and reintervention if necessary. EVAR does not prolong life in patients unfit for OR. Type II endoleak alone is relatively benign.

FUTURE WORK

To find easier ways to monitor sac expansion to trigger timely reintervention.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN55703451.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and the results will be published in full in Health Technology Assessment; Vol. 22, No. 5. See the NIHR Journals Library website for further project information.

Midterm Analysis of Survival and Cause of Death Following Endovascular Abdominal Aortic Aneurysm Repair

Purpose:

To assess rates of complications, secondary interventions, survival, and cause of death following endovascular abdominal aortic aneurysm (AAA) repair over a 10-year period.

Materials and Methods:

Single-institution retrospective cohort study of all patients undergoing primary endovascular aortic aneurysm repair (EVAR) between July 2006 and June 2015. The population constituted 175 patients with 163 fusiform and 12 saccular AAAs. Of these, 149 (85%) were male, with mean age 75.4 (±7.1) years. Patients were followed up until June 30, 2016. Cause of death was determined from the national death register.

Results:

Mean follow-up was 34.4 (±24.4) months. The secondary intervention rate was 9.7%, and there were 4 aneurysm ruptures (0.8% annual incidence). Thirty-day mortality was 0.6%. Survival at 1, 3, and 5 years was 93.1%, 84%, and 64.9%, respectively. Forty-eight patients died during follow-up, 3 secondary to rupture, leading to overall and aneurysm-related death rates of 9.7 and 0.6 per 100 person-years. All other deaths were due to nonaneurysm causes, most commonly cardiovascular (n = 15), pulmonary (n = 13), and malignancy (n = 9). Baseline renal impairment ( P < .001), ischemic heart disease ( P < .05), age greater than 75 years ( P < .05), and urgent/emergency EVAR were associated with inferior long-term survival. Type II endoleak negatively influenced fusiform aneurysm sac regression ( P = .02), but there was no association between survival and occurrence of any complication or secondary intervention.

Conclusion:

The majority of deaths during medium-term follow-up post-EVAR are due to nonaneurysm-related causes. Survival is determined by the following baseline factors: renal impairment, ischemic heart disease, advanced age, and the presence of a symptomatic/ruptured aneurysm.

Ultrasound fusion imaging with real-time navigation for the surveillance after endovascular aortic aneurysm repair

Ultrasound can be an effective alternative to computed tomography for surveillance following endovascular aneurysm repair (EVAR). Recently, ultrasound fusion imaging with the real-time navigation system was introduced. Here we described 3 patients who underwent post-EVAR surveillance using this novel technique. Complete coregistration was achieved in all patients. The origin of left renal artery was selected for the target of coregistration. Ultrasound fusion imaging was useful to differentiate the confusing lesion and to evaluate the complete resolution of endoleak and newly developed delayed endoleak. Ultrasound fusion image with real-time navigation system can be a feasible imaging tool for post-EVAR surveillance.

Endovascular anatomic reconstruction of the iliac bifurcation with covered stentgrafts in sandwich-technique for the treatment of complex aorto-iliac aneurysms

OBJECTIVE

Endovascular anatomic reconstruction of iliac artery bifurcation in aorto-iliac aneurysms using commercial stentgrafts in sandwich-technique by bilateral transfemoral approach.

METHODS

24 patients (mean 73.8±standard deviation 6.8years) with complex aorto-iliac aneurysms (AAA): n=17; diameter 64±15 [48-100]mm; common-iliac-artery (CIA): n=27; 43±15 [30-87]mm; internal-iliac-artery (IIA): n=14; 28±8 [15-43]mm) were prospectively enrolled for EVAR with preservation of the IIA (n=31; bi-lateral n=7). Maintenance of antegrade flow to IIA by iliac reconstruction was performed in sandwich-technique prior to EVAR. Follow-up of 15.0±10.8 [1-40]months included contrast-enhanced ultrasound and computed-tomography after 1week, 3, 6 and every 12months.

RESULTS

Initial technical success for anatomic reconstruction of the iliac arteries in 31 instances was 100%. Primary patency of iliac neo-bifurcations was 90.9% (20/22) at 6months and 84.2% (16/19) at 1year. Postprocedural gutter-endoleaks type 1b were obvious in 6.5% (2/31) of cases, which disappeared 3months later. Aortic/iliac aneurysm-size after 1year decreased (>5mm) in 61.5% of patients. No aneurysm-size increase or late rupture occurred.

CONCLUSIONS

Endovascular reconstruction of the iliac bifurcation with commercial standard stentgrafts is safe and effective. Transfemoral approach allows extension of distal landing zone for EVAR while preserving the internal iliac artery blood-flow, even in unfavorable iliac anatomy.

Hemodynamic Functions of Fenestrated Stent Graft under Resting, Hypertension, and Exercise Conditions

The aim of this study was to assess the hemodynamic performance of a patient-specific fenestrated stent graft (FSG) under different physiological conditions, including normal resting, hypertension, and hypertension with moderate lower limb exercise. A patient-specific FSG model was constructed from computed tomography images and was discretized into a fine unstructured mesh comprising tetrahedral and prism elements. Blood flow was simulated using Navier-Stokes equations, and physiologically realistic boundary conditions were utilized to yield clinically relevant results. For a given cycle-averaged inflow of 2.08 L/min at normal resting and hypertension conditions, approximately 25% of flow was channeled into each renal artery. When hypertension was combined with exercise, the cycle-averaged inflow increased to 6.39 L/min but only 6.29% of this was channeled into each renal artery, which led to a 438.46% increase in the iliac flow. For all the simulated scenarios and throughout the cardiac cycle, the instantaneous flow streamlines in the FSG were well organized without any notable flow recirculation. This well-organized flow led to low values of endothelial cell activation potential, which is a hemodynamic metric used to identify regions at risk of thrombosis. The displacement forces acting on the FSG varied with the physiological conditions, and the cycle-averaged displacement force at normal rest, hypertension, and hypertension with exercise was 6.46, 8.77, and 8.99 N, respectively. The numerical results from this study suggest that the analyzed FSG can maintain sufficient blood perfusion to the end organs at all the simulated conditions. Even though the FSG was found to have a low risk of thrombosis at rest and hypertension, this risk can be reduced even further with moderate lower limb exercise.

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.

Characterizing the evolution of perioperative outcomes and costs of endovascular abdominal aortic aneurysm repair

OBJECTIVE

The purpose of this study is to characterize the evolution in perioperative outcomes and costs of endovascular abdominal aortic aneurysm (AAA) repair (EVAR) by detailing changes in adjusted outcomes and costs over time.

METHODS

National Inpatient Sample (2000-2011) data were used to evaluate patient characteristics, outcomes, and perioperative costs for elective EVAR performed for intact AAA. Outcomes were adjusted for patient demographics and comorbidities, and hospital factors by multivariate analysis. Costs were calculated from hospital cost to charge ratio files and adjusted to 2011 dollars.

RESULTS

From 2000 to 2011, 185,249 patients underwent elective EVAR for intact AAA. The absolute rates of in-hospital major morbidity, mortality, and procedural costs all decreased significantly over time (P < .0001). The prevalence of major comorbidities in patients undergoing EVAR, including obesity, diabetes, and dyslipidemia, all increased significantly over time. After adjusting for multiple demographics, comorbidities, and hospital-level factors, recent outcomes of EVAR (2009-2011) remain superior to the early experience (2000-2002) with respect to mortality and major complications.

CONCLUSIONS

From 2000-2011, the perioperative outcomes of EVAR improved significantly despite a higher prevalence of comorbidities among patients undergoing repair. Concurrently, procedure-associated costs declined. Advanced technology is often implicated in escalating healthcare spending, and the value of novel techniques is often questioned. These findings highlight that, in the case of EVAR, procedural outcomes have improved while the initial costs of repair have declined over time. EVAR offers an interesting example for stakeholders to consider in the era of cost-containment pressures and criticism of nascent, expensive technology in healthcare.

The role of cost-effectiveness for vascular surgery service provision in the United Kingdom

OBJECTIVE

The cost of health care is increasingly becoming an international issue, with many health care systems requiring evaluation of cost when agreeing to fund health care. In the United Kingdom (UK), for example, the National Institute for Health and Care Excellence highlights the importance of using cost-effectiveness analyses to facilitate the effective use of resources. This study evaluates the use of cost-effectiveness analyses and the provision of vascular surgery.

METHODS

A systematic review of published literature was performed. UK-based studies assessing cost-effectiveness or cost-utility of superficial venous interventions, abdominal aortic aneurysm (AAA) repair, and carotid endarterectomy (CEA) were included. All included studies were quality assessed to determine the overall strength of UK economic evidence for each intervention.

RESULTS

Four superficial venous, six AAA, and two CEA studies met the inclusion criteria. After quality assessment, the UK evidence supporting the cost-effectiveness of superficial venous intervention was graded strong. The economic evidence for asymptomatic and symptomatic CEA was graded limited and insufficient, respectively, owing to a paucity of UK literature in this field. There was strong UK economic evidence affirming that endovascular aneurysm repair (EVAR) is unlikely to be a cost-effective alternative to open repair.

CONCLUSIONS

There is strong economic evidence for symptomatic superficial venous intervention. However, funding for varicose vein treatments remains controversial. Future economic analyses are required for symptomatic and asymptomatic CEA to better advise national policy. Despite strong economic evidence, current UK guidance is for EVAR over open repair in the elective setting, with the majority of elective AAA repairs being EVAR.

The power of disruptive technological innovation: Transcatheter aortic valve implantation

We sought to evaluate the principles of disruptive innovation, defined as technology innovation that fundamentally shifts performance and utility metrics, as applied to transcatheter aortic valve implantation (TAVI). In particular, we considered implantation procedure, device design, cost, and patient population. Generally cheaper and lower performing, classical disruptive innovations are first commercialized in insignificant markets, promise lower margins, and often parasitize existing usage, representing unattractive investments for established market participants. However, despite presently high unit cost, TAVI is less invasive, treats a "new," generally high risk, patient population, and is generally done by a multidisciplinary integrated heart team. Moreover, at least in the short-term TAVI has not been lower-performing than open surgical aortic valve replacement in high-risk patients. We conclude that TAVI extends the paradigm of disruptive innovation and represents an attractive commercial opportunity space. Moreover, should the long-term performance and durability of TAVI approach that of conventional prostheses, TAVI will be an increasingly attractive commercial opportunity.

Open vs. endovascular repair of abdominal aortic aneurysm: a comparative analysis

Context:Abdominal aortic aneurysm (AAA) is a condition that is usually asymptomatic, but potentially fatal, and has a prevalence in men over 60 years old ranging from 4.3% to 8%. There are two treatment options available: open surgery (OS) and endovascular treatment (ET).Objective:To compare the results of repairs conducted using these two treatment methods from 2008 to 2013 in a tertiary hospital.Methods:A retrospective analysis comparing 119 patients treated with OS and 219 patients who underwent ET for AAA repair.Results:The ET group was older (71.3 vs. 68.2 years; p<0.001) and had a higher rate of coronary disease (44.7% vs. 27.7%; p=0.002) and a lower ejection fraction (57.6% vs. 64.3%; p<0.001); in turn, the OS group had more chronic obstructive pulmonary disease (16.0% vs. 5.9%; p=0.004) and a smaller proximal infrarenal neck (15.5 mm vs. 23.0 mm; p<0.001). However, there was no difference in ASA classification (American Society of Anesthesiology) (p=0.36). The ET group had less intraoperative bleeding (171 mL vs. 729 mL; p<0.001) and required fewer blood transfusions (11.9% vs. 73.1% p<0.001), and spent shorter stays in both ICU (2.4 vs. 3.5 days; p=0.002) and hospital (5.8 vs. 10.3 days; p<0.001). Thirty-day mortality was similar (OS 5.0% vs. ET 4.1%; p=0.78) and there was also no difference in postoperative complications. The average cost of ET was higher (R$34,277.76 vs. R$4,778.60; p<0.001).Conclusions:Rates of morbidity and mortality were similar, although ET was associated with less bleeding, fewer transfusions and shorter hospital stays, but was more expensive.