Real-world cost analysis of endovascular repair versus open repair in patients with nonruptured abdominal aortic aneurysms

Development and Validation of a Novel Preoperative Risk Score to Identify Patients at Risk for Nonhome Discharge after Elective Endovascular Aortic Aneurysm Repair (EVAR)

BACKGROUND

Nonhome discharge (NHD) to a rehabilitation or skilled nursing facility after elective endovascular aortic repair (EVAR) is uncommon. However, NHD after surgery has an important impact on patient quality of life and postdischarge outcomes. Understanding factors that put patients undergoing EVAR at high risk for NHD is essential to providing adequate preoperative counseling and shared decision making. This study aimed to identify independent predictors of NHD following elective EVAR and to create a clinically useful preoperative risk score.

METHODS

Elective EVAR cases were queried from the Society for Vascular Surgery Vascular Quality Initiative 2014-2018. A risk score was created by splitting the data set into two-thirds for development and one-third for validation. A parsimonious stepwise hierarchical multivariable logistic regression controlling for hospital level variation was performed in the development dataset, and the beta-coefficients were used to assign points for a risk score. The score was then validated, and model performance assessed.

RESULTS

Overall, 24,426 patients were included and 932 (3.8%) required NHD. Multivariable analysis in the development group identified independent predictors of NHD, which were used to create a 20-point risk score. Patients were stratified into 3 groups based upon their risk score: low risk (0-7 points; n = 16,699) with an NHD rate of 1.8%, moderate risk (8-13 points; n = 7,315) with an NHD rate of 7.3%, and high risk (≥14 points; n = 412) with an NHD rate of 21.8%. The risk score had good predictive ability with c-statistic = 0.75 for model development and c-statistic = 0.73 in the validation dataset.

CONCLUSIONS

This novel risk score can predict NHD following EVAR using characteristics that can be identified preoperatively. Utilization of this score may allow for improved risk assessment, preoperative counseling, and shared decision making.

Outcomes and Economic Impact of Hypogastric Artery Management During Elective Endovascular Aortic Repair for Aorto-Iliac Aneurysms

BACKGROUND

To analyze clinical outcomes and perform a macro-costing evaluation of endovascular aortic repair (EVAR) for aorto-iliac aneurysms.

METHODS

This is a retrospective, financially unsupported, physician-initiated observational cohort study. Patients with iliac artery involvement treated with EVAR between January 1st, 2014 and December 31st, 2021 were identified. Inclusion criteria were intact aneurysm, elective EVAR with at least 1 hypogastric artery (HA) treatment, use of bifurcated endograft (EG), and at least 6 months of follow-up. Primary outcomes of interest were overall survival, freedom from aneurysm-related mortality (ARM), freedom from EVAR-related reintervention, and overall EVAR(procedure)-related costs.

RESULTS

We studied 122 (9.1%) patients: 119 (97.5%) were male and 3 (2.5%) females. Median age of patients was 76 years (range, 68.75-81). Overall, 107 (87.7%) patients had both HAs preserved according to following strategy: 45 (36.9%) with flared limbs, 13 (10.6%) with bilateral branched device, and 49 (40.2%) with a combination of flared limb on 1 side and branched device on the contralateral side. Bilateral overstenting was performed in 15 (12.3%) patients. Estimated overall survival was not different between groups of EVAR (Log-rank, P = 0.561). There was only 1 (0.8%) ARM ascertained during the follow-up. Estimated freedom from EVAR-related reintervention was not different among groups (Log-rank, P = 0.464). During the follow-up, 9 (7.4%) patients developed buttock claudication (Society for Vascular Surgery (SVS) grade 1, n = 4, SVS grade 2, n = 5), more frequently in HA overstenting (hazard ratio (HR): 3.6; 95% confidence intervals (CIs): 0.96-13.5, P = 0.058). When all cots were included, branched EVAR still carried the highest burden (P = 0.001) in comparison with the mixed subgroup, the overstenting subgroup, and the flared limbs subgroup.

CONCLUSIONS

Early mortality and pelvic ischemic syndromes rate were acceptably low in all techniques. Hypogastric artery preservation showed lower complication rate in comparison with HA overstenting which, however, appears to be safe an effective for option with similar overall costs for patients who are not candidates for HA preservation based on aortic anatomy.

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.

The Impact of Endovascular Repair of Abdominal Aortic Aneurysms on Vascular Surgery Training in Open Aneurysm Repair

BACKGROUND

Since the introduction of endovascular aneurysm repair (EVAR) in 1992, the number of open AAA repair (OAR) cases continue to decline. The consequence of reduced OAR cases raises valid concerns related to patient safety and the future training of vascular surgeons that need to be appropriately addressed. Our objective is to analyze trends in OAR and EVAR cases and to assess their implications on the quality of vascular surgery training.

METHODS

We analyzed the Accreditation Council for Graduate Medical Education (ACGME) case log database for total clinical experience in OAR and EVAR for graduating vascular surgery fellows (VSFs) finishing 5 + 2 programs between 2002 and 2019 and vascular surgery integrated residents (VSRs) between 2013 and 2019. VSF case totals were calculated by combining average total cases of open and endovascular supra- and infrarenal AAA repair during fellowship years combined with total cases performed during their general surgery residency. VSR case totals included only the cases performed during the 5-year residency period. Isolated Iliac and thoracic aortic aneurysms were excluded from our analysis.

RESULTS

The average number of OAR cases per trainee has decreased by 60% (from 36.9 to 14.7) with a rate of 1.4 cases per year (P < 0.001) for VSF. Meanwhile, EVAR average cases have increased by 102% (from 22 to 44.4). However, there were 2 different trends exhibited with EVAR over the study period. Between 2002 and 2007, EVAR cases tended to increase by 5.9 cases per year (P < 0.001). Whereas, between 2007 and 2019, there was a slightly decreased trend in EVAR cases by 0.3 cases per year (P = 0.01). For VSR, while no significant trend was observed in the mean number of OAR cases (Coef. -0.3, P = 0.2) due to the limited time frame, the proportion of open cases was significantly lower compared to endovascular cases. Additionally, there were 2 different trends exhibited with EVAR over the study period. Between 2013 and 2015, EVAR cases tended to increase by 1.7 cases per year (P = 0.1). Whereas, between 2015 and 2019, there was a slightly decreased trend in EVAR cases by 0.2 cases per year (P = 0.007).

CONCLUSIONS

A significant reduction in average OAR cases and an increase in EVAR cases were observed over the study period. Vascular surgery training programs may need to introduce further training programs in open surgical repair to ensure vascular surgery trainees have the required technical skills and expertize to perform such a high-risk procedure safely and independently.

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.

Abdominal aortic aneurysm clinical practice guidelines: a methodological assessment using the AGREE II instrument

OBJECTIVES

Abdominal aortic aneurysm (AAA) clinical practice guidelines (CPGs) provide evidence-based information on patient management; however, methodological differences exist in the development of CPGs. This study examines the methodological quality of AAA CPGs using a validated assessment tool.

METHODS

Medline, EMBASE and online CPG databases were searched from 1946 to 31 October 2021. Full-text, English language, evidence-based AAA CPGs were included. Consensus-based CPGs, summaries of CPGs or CPGs which were only available on purchase were excluded. Five reviewers assessed their quality using the Appraisal of Guidelines for Research and Evaluation II instrument. An overall guideline assessment scaled score of ≥80% was considered as the threshold to recommend CPG use in clinical practice.

RESULTS

Seven CPGs were identified. Scores showed good inter-reviewer reliability (intraclass correlation coefficient 0.943, 95% CI 0.915 to 0.964). On average, CPGs performed adequately with mean scaled scores of over 50% in all domains. However, between CPGs, significant methodological heterogeneity was observed in all domains. Four CPGs scored ≥80% (European Society of Cardiology, the Society of Vascular Surgery, the European Society of Vascular Surgery and the National Institute of Health and Care Excellence), supporting their use in clinical practice.

CONCLUSIONS

Four CPGs were considered of adequate methodological quality to recommend their use in clinical practice; nonetheless, these still showed areas for improvement, potentially through performing economic analysis and trial application of recommendations. A structured approach employing validated CPG creation tools should be used to improve rigour of AAA CPGs. Future work should also evaluate recommendation accuracy using validated appraisal tools.

Remodeling of abdominal Aortic Aneurysm Sac following EndoVascular Aortic Repair: Association with Clinical, Surgical, and Genetic factors

After successful EndoVascular Aortic Repair (EVAR), abdominal aortic aneurysms (AAA) sac will undergo negative remodeling (i.e. shrinkage) as a measure of successful exclusion. Determinants of shrinkage after EVAR are not fully known. In 84 post-EVAR patients, time course of AAA diameter after repair and occurrence of endoleaks (ELs) have been correlated with clinical history, medications, anthropometric data, vascular anatomy, and matrix metalloprotease (MMP) genetic variants (namely MMP-1 rs1799750, MMP-3 rs35068180, MMP-9 rs2234681, rs917576, rs917577, MMP-12 rs652438, and TIMP1 rs4898). During follow-up, 41 ELs were detected in 37 patients (44%, 10.4 events/100 pt./y), accounting for AAA dilation or reduced shrinkage (P<0.001). High-flow ELs (type 1 and/or 3) occurrence was associated with warfarin use, MMP9 rs17577 polymorphism, and unfavorable anatomy, while low-flow type 2 ELs occurred more often in TIMP1 rs4898 non-T carriers. In EL-free patients, AAA diameter decreased for the first three years, (-4, -3 and - 2 mm/year respectively) and remained stable thereafter. Shrinkage between two measurements (n= 120) was associated with smaller AAA diameter at the baseline, peripheral arterial disease (PAD), patients' older age at intervention, and G-/G- genotype in MMP1 rs1799750 (binary logistic regression, P=0.0001). Aneurysmal sac shrinking occurs for few years after EVAR, only in patients without EL, and is related to older age, PAD, smaller aneurysm size and putative lower MMP1 expression while EL occurrence prevents such a remodeling and is mainly related to local-acting factors like unfavorable anatomy, anticoagulation, and MMP9 and TIMP1 genetic polymorphisms.

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.

A Randomised Controlled Trial Assessing the Effects of Peri-operative Fenofibrate Administration on Abdominal Aortic Aneurysm Pathology: Outcomes From the FAME Trial

OBJECTIVE

Experimental studies suggest that fenofibrate prevents abdominal aortic aneurysm (AAA) development by lowering aortic osteopontin (OPN) concentration and reducing the number of macrophages infiltrating the aortic wall. The current study examined the effects of a short course of fenofibrate on AAA pathology in people with large AAAs awaiting aortic repair.

METHODS

This randomised double blind parallel trial included male and female participants aged ≥ 60 years who had an asymptomatic AAA measuring ≥ 50 mm and were scheduled to undergo open AAA repair. Participants were allocated to fenofibrate (145 mg/day) or matching placebo for at least two weeks before elective AAA repair. Blood samples were collected at recruitment and immediately prior to surgery. AAA biopsies were obtained during aortic surgery. The primary outcomes were (1) AAA OPN concentration; (2) serum OPN concentration; and (3) number of AAA macrophages. Exploratory outcomes included circulating and aortic concentrations of other proteins previously associated with AAA. Outcomes assessed at a single time point were compared using logistic regression. Longitudinal outcomes were compared using linear mixed effects models.

RESULTS

Forty-three participants were randomised. After three withdrawals, 40 were followed until the time of surgery (21 allocated fenofibrate and 19 allocated placebo). As expected, serum triglycerides reduced significantly from recruitment to the time of surgery in participants allocated fenofibrate. No differences in any of the primary and exploratory outcomes were observed between groups.

CONCLUSION

A short course of 145 mg of fenofibrate/day did not lower concentrations of OPN or aortic macrophage density in people with large AAAs.

Financial viability of endovascular aortic repair in the modern era

BACKGROUND

In the current era of cost containment, the financial impact of high-cost procedures such as endovascular aneurysm repair (EVAR) remains an area of intensive interest. Previous reports suggested slim to negative operating margins with EVAR, prompting widespread initiatives to reduce cost and to improve reimbursement. In 2015, the Centers for Medicare and Medicaid Services (CMS) announced the reclassification of EVAR to more specific diagnosis-related group (DRG) coding and predicted an overall increase in hospital reimbursement. The potential impact of this change has not been described.

METHODS

Patients undergoing elective EVAR at a single institution between January 2014 and December 2018 were identified retrospectively, then stratified by date. Group 1 patients underwent EVAR before DRG change in 2015 and were classified with DRG 237/238, major cardiovascular procedure. Group 2 patients underwent EVAR after the change and were classified as DRG 268/269, aortic/heart assist procedures. The total direct cost included implant cost, operating room (OR) labor, room and board, and other supply costs. Net revenue reflected real payer mix values without extrapolation based on standard Medicare rates. Hospital profit was defined as the contribution to indirect (CTI), subtracting total direct cost from net revenue.

RESULTS

A total of 188 encounters were included, 67 (36%) in group 1 and 121 (64%) in group 2. Medicare patients composed 84% of group 1 and 81% of group 2. CTI (profit) increased by $4447 (+123%) from $3615 in group 1 to $8062 in group 2. Net revenue per encounter increased by $2054 (+7.1%). In group 1, the higher reimbursement DRG code 237 was applied in 5 of 67 (7.5%) patients, whereas DRG code 268 was assigned in 19 of 121 (15.1%) patients in group 2. Total direct cost per encounter decreased by $2012 (-7.9%). This decrease in cost was driven by a reduction in implant cost, from a mean $16,914 per encounter in group 1 to a mean $15,655 in group 2 (-$1259 or -7.4% per encounter) and by a decrease in OR labor cost, $2838 in group 1 to $2361 in group 2 (-$477 or -17.0% per encounter).

CONCLUSIONS

A significant improvement in hospital CTI was observed for elective EVAR during the course of the study. The increased DRG reimbursement after the Centers for Medicare and Medicaid Services coding changes in 2015 was a major driver of this salutary change. Notably, efforts to reduce implant and OR cost as well as to improve coding and documentation accuracy over time had an equally important impact on financial return.

Longitudinal Spending on Endovascular and Open Abdominal Aortic Aneurysm Repair

BACKGROUND

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

METHODS AND RESULTS

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

CONCLUSIONS

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

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.